CN1242710A - Liquid Syringe - Google Patents

Abstract

A liquid medicine syringe (2) comprises: an air detection system (122) for detecting air in the neck of a syringe; a manual control lever (29) for controlling the movement of a syringe drive cylinder; magnetic conductors (94) for transmitting a magnetic field from a panel of a power head to an internal circuit board, thereby enabling detection of different panels; a tilt sensor (158) for detecting the tilt angle of the power head to control the movement speed formed by the manual control lever and to control a reversible display (30); and monitoring microcontrollers (192, 196, 198) for monitoring the operation of a central processing unit (175, 193, 194) controlling the syringe, thereby detecting and responding to error conditions.

Description

Liquid Syringe

field of invention

The present invention relates to a syringe for injecting medicinal liquid into animals.

Background of the invention

In many medical situations, it is necessary to inject medicinal liquid into the patient's body during diagnosis or treatment. An example is the use of a powered auto-injector to inject contrast media into a patient to enhance CT, angiography, magnetic resonance or ultrasound imaging.

Syringes suitable for this and similar applications must generally employ relatively large volume syringes and be capable of producing relatively high flow rates and injection pressures. For this reason, injectors in this application are usually motorized and include a large, heavy injector motor and drive train. For ease of use, the motor and drive train are usually housed in an injector head supported by an arm mounted on the floor, wall or ceiling.

The syringe head is usually hingedly mounted on the arm so that the syringe head can be tilted up (so that the injection nozzle is higher than the rest of the syringe) to facilitate filling of the syringe and can be tilted down (to make the syringe The injection nozzle is lower than the rest of the injection tube) for injection. Tilting the syringe head in this manner facilitates expulsion of air out of the syringe during injection, thereby reducing the likelihood of air being injected into the subject being injected. Still, the accidental injection of air into a patient remains a serious safety concern.

In addition to the syringe heads discussed above, many syringes contain a separate console to control the syringe. The console usually contains programmable circuitry to automatically control the injector by programming so that the injector operates in a predictable manner and can be synchronized with the operation of other equipment, such as scanners or imaging equipment.

Thus, at least a portion of the injection process is usually controlled automatically; however, there are usually several parts of the filling process as well as the injection process that are performed by the operator using the manual motion controller of the syringe head. Typically, manual motion controls include buttons for controlling reverse and forward movement of the syringe drive cylinder to fill or empty the syringe, respectively. In some cases, a set of buttons is used to initiate or control the speed of movement of the drive cylinder. The injector head also typically contains a gauge or display to show the operator injection parameters, such as the remaining volume of the syringe, for use by the operator in controlling the injector. Unfortunately, operators have found it cumbersome to use the manual movement buttons and read the syringe head gauges and displays for a number of reasons including at least the need to align the syringe head in the up fill position with the down injection Tilting between positions, changing the position of the manual motion button relative to the operator, and at certain tilt angles can make the gauge or display difficult to read.

In many applications it is desirable to have a syringe with multiple syringes of different sizes. For example, it is desirable for syringes used in pediatrics to be smaller than those used in adults. To facilitate the use of syringes of different sizes, the syringe is provided with removable panels, each different panel shaped to fit a particular size syringe. Typically, the injection parameters of the syringe can be adjusted by detecting which panel is mounted on the syringe, for example, by detecting the presence of a magnet on the panel with a magnetic detector mounted on the syringe housing. Unfortunately, installing a magnetic detector in the housing of the syringe head adds complexity and expense to the manufacture of the syringe head.

Summary of the invention

According to the present invention, these aspects of normal syringe operation are improved.

In particular, a syringe according to the present invention is characterized as including an air bubble detection system positioned adjacent the injection nozzle for detecting the presence of air in the syringe. An air bubble detection system electrically connected directly to the control circuit in the syringe allows the syringe to detect air in the injection nozzle and, if air is detected, to stop any pending or ongoing injection. Since the air is detected before leaving the syringe and before passing through the catheter leading to the patient, rather than at some intermediate point in the catheter, the syringe is more likely to detect the air early enough that it arrives at the The patient previously withheld or discontinued the injection.

In the particular proposed embodiment, the air detector generates a light beam and directs this light beam into the injection nozzle, the light beam is reflected by the inner wall of the injection nozzle and returns to a detector. Other methods of air detection, such as ultrasonic air detection, are also possible with a probe mounted on the injection nozzle with the same advantages and are included within the scope of the present invention.

Another feature of the syringe is the injection nozzle, which includes a projecting transparent section that is mechanically connected to the light source in the air detector to allow light to pass into the injection nozzle and reflect from the inner wall of the mouth. Return to the detector. The overhanging section forms a lens for concentrating light and entering it into the injection nozzle so that the light is properly reflected on the inner wall of the injection nozzle.

The syringe according to the present invention also includes a manual filling/discharging lever for the operator to control the syringe conveniently. The control lever comprises a rod movable between home, forward and reverse positions, wherein movement of the rod toward the forward position causes the syringe to move the piston cylinder forward to expel fluid from the syringe, Movement of the rod toward the reverse position causes the syringe to reverse the piston drive cylinder to draw liquid into the syringe.

In particular embodiments, the lever is mounted on a hinge and is urged toward the original position by return springs located on opposite sides of the lever. As the rod is rotated away from its original position, the rod will gradually bend both springs as the rod is rotated through an increasing angle. A detector, in particular a rotary potentiometer, is used to detect the angle of rotation of the rod so that this angle can be used to control the speed of movement of the piston cylinder. With this structure and control lever, the relative position of the lever and (if desired) the return torque applied by the spring to the lever can be configured to be approximately proportional to the flow rate of liquid into or out of the syringe, thereby providing the operator with information about the operation of the syringe. intuitive feedback information. Alternatively, the injector may control the injection pressure generated by the injector according to the angle of rotation of the lever, thereby providing feedback to the operator as to the applied injection pressure.

As a safety feature, in the particular embodiment presented, said return spring and lever are elements in an electrical circuit for generating a motion control signal. When one of the return springs is broken, the central processing unit displays a fault signal according to this signal or disables the manual movement control lever to control the injector, so that in this case, the injector does not respond possibly due to a broken spring The resulting movement of the rod inadvertently shifting from its original position.

As an aid to the filling process of the syringe, an additional stop spring is positioned relative to the lever so as to vary the return torque exerted on the lever when the lever is rotated beyond a given angle from its original position. The result is a "stop" signal recognizable by the operator, ie an angle at which the resistive torque increases significantly. This detent angle can have any desired significance, but in the presented embodiment, this angle corresponds to a recommended maximum velocity for syringe filling that liquid can be drawn into the syringe without significant bubble generation. Increased maximum speed. As with other springs, the stop spring can be an electrical contact that generates a second control signal indicating that the lever has been rotated to the stop angle, allowing the syringe control circuit to calibrate when the lever contacts the stop spring speed so that this rod position corresponds to the recommended maximum speed. Alternatively, the second control signal can also be used to prevent the operator from attempting to fill the syringe at any faster flow rate.

In addition to the intuitive feedback function obtained from the previously described fill/discharge lever, the syringe according to the present invention features a tilt compensating display. The injector head includes an inclination angle sensor to detect the inclination angle of the injector head, and the injector head selects one of the two display orientations according to the inclination angle. As a result, whether the syringe is tilted up to fill or down to inject, the display always maintains an orientation that is convenient for the operator to read.

In a particularly proposed embodiment, the display is a light emitting diode display comprising elements arranged such that the display displays the same information whether it is in a vertical orientation or in a reverse orientation. However, other embodiments may be used, such as using a liquid crystal display, or a full pixel display that allows the characteristics and orientation of the display to be completely changed.

As an additional aspect of this feature, tilt detection circuitry is also incorporated into the syringe to ensure proper operation of the syringe. For example, manual movement of the control lever provides a greater range of fill and discharge speeds when the syringe head is tilted up than when the syringe head is tilted down. In addition, the injector prevents automatic injection unless the injector head is tilted downward, and/or when the injector tip does not reach a sufficient downward tilt, the injector will warn the operator of possible air injection.

The syringe head according to the present invention has a compact modular structure for ease of manufacture and use. In particular, all control circuits can be combined on a single printed circuit board for this purpose. In particular, a feature of the syringe of the present invention is the use of a magnetic conductor such that magnetic field energy from a magnet in the faceplate of the syringe passes through the syringe housing and is transmitted to a magnetic detector (such as a Hall sensor) mounted on the main circuit board. effect switch) nearby. By using a magnetic conductor that carries the magnetic field through the syringe housing, it is possible to use a magnetic detector that can be mounted on a circuit board, thus significantly reducing the overall cost.

In addition to the aforementioned safety features, injectors according to the present invention also include a hardware safety feature to detect processor or software failures and prevent erroneous injections. Specifically, the injector head contains a central processor for controlling all functions of the injector head, and a monitoring microcontroller for monitoring the operation of the central processor. The central processing unit transmits information reflecting its working status to the monitoring microcontroller. The monitoring microcontroller is also used to monitor the manual control action of the syringe head and the movement of the syringe drive cylinder to ensure that these control actions and movements are consistent with the processor status reflected by the central processor. If the two are not the same, the monitoring microcontroller The controller stops operation of the syringe head.

In a particularly proposed embodiment, each of the injector head, console, and power pack contains a central processing unit, and the three central processing units communicate with each other to operate the injector in various states , and each central processing unit is connected to a monitoring microcontroller, and the monitoring microcontroller also performs the same two-way communication to ensure that the central processing units individually and collectively operate correctly.

The above and other features, aspects, objects and advantages of the present invention will be made more apparent by the accompanying drawings and explanations thereof.

Brief description of the drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate some embodiments of the invention and, together with the general description of the invention given above and the detailed description of the embodiments given below, serve to explain the principles of the invention .

Figure 1 is a perspective view of an injector according to the principles of the present invention, comprising a powerhead, console and power pack (under a cover), with the injection tube, pressure jacket, heating pad and air detection module removed;

Figure 2 is a perspective view of the power head of the syringe shown in Figure 1, with a pressure jacket, injection tube, and heating pad mounted thereon, showing details of the power head display, manual control lever, and support arm fixture;

Fig. 3 is an exploded view of the internal structure of the power head shown in Fig. 2, showing the panel, circuit board, piston cylinder transmission device and housing in detail;

Fig. 4 is a partial sectional view of the internal structure of an assembled power head along line 4-4 in Fig. 3;

Fig. 5 is a partial cross-sectional view along line 5-5 in Fig. 4, showing the relative positions of the circuit board, the housing, the display and the magnetic conductor in the housing;

Figure 6 is a partially cutaway perspective view of the manual control lever assembly;

Figure 7A is a cross-sectional view of the manual control lever assembly shown in Figure 6 along line 7A-7A in Figure 6, showing the return and stop springs;

Figure 7B is a cross-sectional view of the manual control lever assembly, showing the manual control lever moved from its original position to a position in contact with the stop spring;

Figure 7C is an electrical schematic diagram of a circuit consisting of a manual control lever, a reset and a stop spring;

Figure 8 is a perspective view of a heating pad for heating liquid in a syringe barrel;

Fig. 9 is a partial cross-sectional view of the injection tube installed in the pressure jacket when the air detection module is in place, showing the internal structure of the air detection module and its interaction with the injection nozzle;

Fig. 10 is a view of the air detection module along line 10-10 in Fig. 9, wherein the injection tube and the pressure sleeve are removed;

Figure 11A is an electrical block diagram of the analog circuit in the power head, including temperature control, air detection and manual control circuits;

Figure 11B is an electrical block diagram of the digital control circuit in the power head, including a central processing unit, a monitoring microcontroller, digital status, control and interface connections;

Fig. 11C is the electrical block diagram of power head, power pack, central processing unit in the console, monitoring microcontroller and their interconnection;

Figure 12 shows the temperature control algorithm of the heating pad in the central processing unit of the power head;

Figure 13A shows the tilt range determined by the software in the powerhead microprocessor used to control the operation of the injector, and Figure 13B shows the elements in the powerhead's display and the typical output of the display when the powerhead is at a first tilt angle mode, and FIG. 13C shows the same information output by the display similar to FIG. 13B when the power head is at the second tilt angle.

Detailed Description of Specific Embodiments

Referring to FIG. 1, a syringe 20 according to the present invention includes various functional components, such as a power head 22, a console 24, and a power pack 26 (installed under a cover). A syringe 36 (FIG. 2) is mounted on the syringe 20 and is located in the panel 28 of the powerhead 22, along with various levers for filling the syringe with fluid, such as that required for CT, angiography, or other procedures agent, which is then injected into a subject under the supervision of an operator or a preprogrammed controller.

The powerhead 22 includes a manual motion control lever 29 to control the movement of the internal drive motor, and a display 30 to show the operator the current status and operating parameters of the injector. The console 24 includes a touch screen display 32 that can be used by the operator to remotely control the operation of the injector 20, and can also be used to program and store programs that automatically control the operation of the injector 20, which can then be accessed after the operator activates the injector. The syringe does it automatically.

The power head 22 and the console 24 are connected to a power pack 26 via cables (not shown). The power pack 26 contains an injector power supply, interface circuitry for connecting the console 24 to the powerhead 22, and additional circuitry for interfacing the injector 20 with a remote control system, such as a remote console, hand or foot remote switch, or original equipment Other remote connectors provided by the manufacturer (OEM) for, for example, synchronizing the operation of the injector 20 with the exposure of the imaging system X-rays.

The power head 22, console 24 and power pack 26 are mounted on a chassis 34 which includes a support arm 35 supporting the power head 22 to facilitate positioning of the power head 22 near the test object. However, other mounting arrangements are also possible; for example, the console 24 and power pack 26 may be placed on a table or mounted on an electronics rack in the laboratory, while the power head 22 may be mounted on the ceiling, floor, or wall. supported by the support arm.

Referring now to FIG. 2, in operation, a syringe 36 and pressure sleeve 38 are mounted on the power head 22 so that a motor inside the power head 22 can be energized to drive a piston 37 toward and away from the barrel of the syringe 36. A discharge nozzle 40 of the syringe moves to expel liquid from the syringe 36 or to fill the syringe with liquid. The pressure sleeve 38 is used to support the outer wall of the injection tube 36 to protect the wall of the injection tube 36 from failure when the injection pressure is high.

The injection tube 36 and the pressure jacket 38 are made of a transparent plastic through which the operator can see the current position of the piston 37 and whether there is liquid or air between the piston 37 and the discharge nozzle 40 . Thus, as described above, the operator can tilt the powerhead 22 upward, fill the syringe 36 with fluid from a fluid source and visually monitor the filling process, and thereafter connect the syringe to the catheter leading to the patient. Remove the air from the syringe and visually monitor the fluid level in the syringe. When the air has been removed, tilt the syringe down and inject the fluid into a subject.

To facilitate the priming process and other manipulations during injection into a subject, the powerhead 22 incorporates a manual movement control lever in the form of a rotatable rod 29 . In particular, the rod 29 is rotatable about an axis of rotation located in the powerhead 22 . When the manual motion control lever 29 is in its original position, as shown in FIG. 2 , no piston movement occurs in the power head 22 . However, when the manual movement control lever 29 is rotated toward the syringe 36 , positive piston movement is generated in the powerhead 22 to expel liquid or air from the syringe 36 . Additionally, when the manual movement control lever 29 is rotated away from the syringe 36 , reverse piston motion is generated in the powerhead 22 to fill the syringe 36 with liquid or air. The detailed structure and operation of the manual motion control lever 29 will be explained later with reference to FIGS. 6-7C.

To ensure that the fluid injected into the subject remains at around body temperature, a heating pad 42 is mounted against the outer wall of the pressure jacket 38 . The heating pad 42 includes an electric heater that generates heat to regulate the temperature of the liquid in the injection tube 36 . Heating pad 42 (shown separately in FIG. 8 ) is mounted on a post 44 extending from panel 28 and holding heating pad 42 in thermally conductive contact with pressure jacket 38 .

At the rear end of the powerhead 22 is an indicator light 46 (covered by a light diffusing cover) for displaying the status of the powerhead, as discussed in more detail below.

Please refer now to Figure 3 to explain the internal structure of the power head.

The powerhead 22 is made up of two outer half-shells 47a and 47b. The half shells 47a and 47b cooperate to form the complete housing of the powerhead 22 . The upper half shell 47a contains an opening for displaying the display 30, the indicator light 46 and a support surface for supporting a shaft 48 to which the manual motion control lever 29 is attached. The detailed structure of the manual movement control lever installed inside the upper half shell 47a will be discussed in further detail later.

The lower half shell 47b contains an opening through which a knob 49 is connected to the internal drive chain. Knob 49 can be turned by hand to move the drive chain of the piston cylinders, thereby precisely controlling the movement of the cylinders and enabling the powerhead to move even if an electrical failure renders the powerhead 22 inoperative. A second opening 51 on the lower half shell 47b is used to connect the power head circuit board 55 (see below) with the heating pad 42 (see FIGS. 2, 8) and the air detector attachment (see FIGS. 9, 10) The wires are connected.

The lower half shell 47b also includes a mounting rail (on the opposite side of the recess 50 in the lower half shell 47b) for receiving a mount 52 for mounting the half shell 47b on a articulated arm On, for example, the arm 35 shown in FIGS. 1 and 2 . The fixing part 52 can be inserted into the installation guide rail of the lower half-shell 47b from any side of the power head 22, so as to install the power head 22 on any side of a test bench. A knob 53 is used to fix the fixing member 52 in the mounting rail of the lower half-shell 47b.

The internal structure of the powerhead 22 includes a circuit board 55 that carries substantially all of the circuitry that controls the operation of the powerhead 22 . Notable components on circuit board 55 include magnetic detectors 56 a , 56 b and 56 c and flag sensor 58 . The function of the magnetic detectors 56a, 56b, 56c and the flag sensor 58 will be explained in detail below.

Below the circuit board 55 in the power head 22 is installed a drive chain 60 for moving the piston drive cylinder 62 . Drive chain 60 comprises a rotary motor 63 controlled by circuit board 55 which (via a gearbox 68 ) rotates a drive gear 64 . The transmission gear 64 meshes with a main gear 65, and the main gear 65 drives a ball screw 66 to rotate. The piston transmission cylinder 62 is installed on a ball screw nut 67, and the ball screw nut 67 can convert the rotational motion of the ball screw 66 into a linear movement of the piston transmission cylinder 62 in and out of the power head 22, so that the piston transmission cylinder 62 can be installed on the power head 22 A plunger 37 (FIG. 2) of a syringe 36 moves. The knob 49 is connected to the axis of the drive gear 64 so that the drive chain 60 can be rotated by hand and the piston drive cylinder moved.

These elements of the drive chain 60 are mounted on a drive housing 69 . When the upper and lower half shells 47a and 47b are assembled around the drive shell 69, the front surface 70 of the drive shell 69 is exposed. The faceplate 28 of the injector is secured to the front face 70 so that a syringe can be mounted to the front face 70 of the drive housing 69 so that the plunger drive barrel 62 can engage and move the plunger 37 .

Panel 28 is hinged to front face 70 by a hinge pin 72 . When panel 28 is attached to front surface 70 by hinge pin 72, panel 28 is rotatable in direction 73 on hinge pin 72 and movable a limited distance in direction 74 along the hinge pin. This combination of rotation and movement allows the faceplate 28 to engage and disengage the front surface 70, thereby allowing syringes to be installed and removed from the faceplate 28 and simultaneously connect and disconnect the syringe plunger to the plunger drive cylinder 62.

When the panel 28 is fully engaged on the front surface 70, the flaps 75a and 75b on the panel 28 fit into the grooves 76a and 76b of the front surface 70, respectively. This coordination relationship is shown in Figure 4. If it is necessary to disengage the panel 28 from the front surface 70, the panel 28 can be moved in a direction 74 to disengage the wings 75a and 75b from the grooves 76a and 76b, so that the panel 28 can be moved around the hinge pin 72 in a direction 73 (Fig. 3) Rotate so that the injection tube mounted on panel 28 is accessible.

To facilitate movement of the panel 28 in direction 74 , a cam lever 78 is mounted on the drive housing 69 between the panel 28 and the drive housing 69 . The cam lever 78 is fixed to and rotatable on a cam lever shaft 79 mounted in the drive housing 69 . Cam lever 78 includes a knob 81 extending toward faceplate 28 . The knob 81 cooperates with a channel 80 formed on the inner surface of the panel 28 (see FIG. 4 ), so that the rotation of the cam lever 78 can drive the knob 81 to move the panel 28 in the direction 74, thereby causing the wing 75a and 75b engage and disengage slots 76a and 76b.

An index washer 82 is mounted on the cam shaft 79 and held in place by a nut 83 . The hole on the index washer 82 and the cam lever 78 to which the cam lever shaft 79 is connected is keyed so that the cam lever 78 and the index washer 82 can be aligned with each other in orientation. Since both the flag washer 82 and the cam lever 78 are keyed to the shaft 79, rotating the cam lever 78 will cause the shaft 79 and the flag washer 82 to rotate. Flag surface 84 extends from flag pad 82; movement of the flag surface due to rotation of cam lever 78 will be sensed and used to determine whether panel 28 is engaged with powerhead 22 as described hereinafter.

Referring now to FIGS. 3 and 4 , when the powerhead 22 is in the position shown in FIG. 4 , the flag pad 82 is located on the circuit board 55 opposite the flag sensor 58 . Flag sensor 58 generates a beam of light that is reflected back and detected by sensor 58 when flag surface 84 is positioned opposite sensor 58 . Cam lever 78 and flag spacer 82 are keyed to shaft 79 so that flag surface 84 can rotate opposite sensor 58 only when cam lever 78 is in the position shown in FIG. The panel 28 moves into position to engage the front surface 70 of the drive housing 69 . Thus, when the flag surface 84 is opposite the sensor 58, this means that the panel is in the closed position, ready for filling or injection.

Power head 22 includes a safety lock to prevent cam lever 78 from rotating to a disengaged position when piston drive cylinder 62 is not fully retracted. Specifically, referring to FIG. 4 , a spring-loaded lock plate 86 is mounted on the drive housing 69 in such a way that it can move in translation along direction 90 . Screws 87 hold the lock plate 86 to the drive housing 69 and allow this translational movement. A spring 88 is connected between the lock plate 86 and the transmission housing 69 to provide a force to make the lock plate 86 tend to slide towards the front surface 70 of the transmission housing 69 into the position shown in FIG. 4 .

When the lock plate 86 is in this forwardmost position, the front corner 89 of the lock plate 86 is adjacent to the index pad 82 as shown in FIG. 4 . As a result, the interference between the notch 85 (see FIG. 3 ) on the flag washer 82 and the front corner 89 of the lock plate 86 prevents the flag washer 82 (and the cam lever 78 ) from coming out of the way shown in FIG. 4 . The engaged position rotates to a disengaged position in which the panel is disengaged from the front face 70 of the drive housing 69 and can be unscrewed from the front face 70 to replace a syringe. However, when the lock plate is slid back in direction 90 (against the force of spring 88), the interference between front corner 89 and notch 85 is eliminated, allowing cam lever 78 to rotate toward a disengaged position.

A joint 91 on the piston drive cylinder 62 engages the lock plate 86 so that when the piston drive cylinder 61 is withdrawn from the panel 28 to a rearmost position, the joint 91 engages the lock plate 86 and moves the lock plate to its on the rear position. However, when the piston drive cylinder 62 moves forward from this position, the force of the spring 88 will move the lock plate to its forward position. Thus, as a result of the interaction between piston drive cylinder 62, lock plate 86 and index shim 82, panel 28 cannot translate in direction 74, i.e., disengage from front face 70 of drive housing 69, unless piston drive cylinder 62 is positioned therein. In the rearmost position. This interlock function prevents an operator from attempting to disengage faceplate 28 from faceplate 70 when piston drive cylinder 62 extends into the interior of a syringe mounted on faceplate 28 .

Referring now to Figures 4 and 5, three magnetic conductors 94a, 94b and 94c are shown. These conductors are made of a high-permeability, low-coercivity material, such as steel or iron, and are inserted into holes in the front surface 70 of the drive housing 69 .

Each panel 20 may be provided with permanent magnets inserted at locations that align with the locations of the three magnetic conductors 94a, 94b and 94c. There may be three, two, one or no permanent magnets and the magnets may face the magnetic conductors 94a, 94b and 94c with their north or south poles.

Panel 28 shown in FIG. 4 includes two permanent magnets 96a and 96b aligned with magnetic conductors 94a and 94b, respectively. However, no magnets are located opposite the magnetic conductor 94c in the faceplate 28 shown in FIG. 4 .

A variety of different panels 28 may be used in the powerhead 22 shown in FIGS. 3 and 4 . Different panels 28 may be used to accommodate different types of syringes 36 for the powerhead 22; for example, one panel sized for low volume pediatric syringes and another panel sized for adult volume syringes. The priming syringe may be of a different size or gauge than the syringe purchased empty. Different panels 28 are required to accommodate these different size syringes.

The circuitry on the circuit board 55 needs to be able to detect which panel is mounted on the powerhead 22 . First, the control circuit must determine whether an air detection module is attached to the panel. In addition, different types of syringes 36 may have different lengths, in which case the powerhead 22 must be able to compensate for this length variation when determining the end-of-travel position of the piston cylinder and calculating the volume of fluid in the syringe 36 . Likewise, under the same operating speed of the piston drive cylinder 62, the flow rates of syringes of different diameters are different; when converting the required flow rate into the operating speed of the piston drive cylinder 62, the control circuit must compensate for this difference.

For identification purposes, the combination of permanent magnets mounted in alignment with the magnetic conductors 94a, 94b and 94c in the front surface 70 of the drive housing 69 on each different panel 28 is unique. Specifically, the panel shown in FIG. 4 includes two permanent magnets facing the magnetic conductors 94a and 94b, respectively. There may be only one permanent magnet on the other panel, which faces the magnetic conductor 94b. There may be three permanent magnets on the third panel facing all magnetic conductors 94a, 94b and 94c respectively. There can be no magnets at each position, and the polarity of the magnets can also be changed, so that these magnets can generate a total of 27 (33) magnet combinations, so that 27 different panels can be uniquely identified in this way.

To detect the number and position of the permanent magnets in the panel, the control circuitry in the powerhead 22 includes magnetic detectors 56a, 56b and 56c, which may be, for example, Hall effect sensors (or, alternatively, reed switches). The three magnetic detectors 56a, 56b and 56c are located at one edge of the circuit board 55 and are aligned with the inner ends of the three magnetic conductors 94, as can be seen by comparing FIGS. 4 and 5 . Typically, drive housing 69 is made of a non-magnetic material, such as aluminum. Like this, the magnetic field that permanent magnet 96a and 96b produces can pass through permeable magnetic conductor 94a, 94b and 94c, and enters near magnetic detector 56a, 56b and 56c, thereby can be detected on the panel 28 far away from panel 28 by circuit board 55 presence of permanent magnets.

These magnetic conductors significantly reduce the cost of the electronics portion of the powerhead 22 by conducting the magnetic field from the permanent magnets on the faceplate 28 to the remote detectors located on the circuit board 55 . While it is possible to purchase separate magnetic detectors and mount them to the front surface 70 of the drive housing 69, separate magnetic detectors are generally more expensive than detectors that can be mounted to a printed circuit board. In addition, the use of independent magnetic detectors requires the manufacture of multiple separate circuit boards and/or wiring harnesses and their installation in the housing of the power head, and then connected to the main circuit board through suitable cables, therefore, the same as the present embodiment Compared with the structure in which the detector is mounted on the main circuit board, the previous structure will make the manufacture of the power head 22 more complicated, expensive and time-consuming. Therefore, the use of magnetic conductors 94a, 94b and 94c can significantly reduce the manufacturing cost of power head 22.

Referring to Figure 6, the manual motion control lever can now be explained. As previously indicated, rotation of the manual motion control lever 29 in the forward or reverse direction indicates that the operator wishes to move the piston cylinder in the forward or reverse direction, respectively. To determine the direction and angle of rotation of the rod 29, a rotary potentiometer 98 is connected to the shaft 48 of the rod 29, such that rotation of the rod 29 will rotate a brush inside the potentiometer 98, thereby producing a varying resistance, the The resistance can be detected by the power head control circuit.

As shown above, when the control rod 29 rotates positively along the direction 99, the control circuit will detect this rotational action according to the electric signal generated by the potentiometer 98, so that the transmission cylinder 62 of the piston will move forward, that is, from the power head The container moves outwards, and the moving speed is proportional to the angle at which the control rod 29 deviates from the original position shown in FIG. 6 . On the other hand, when the control rod 29 rotates in the opposite direction along the direction 100, the control circuit will detect this rotation action according to the electric signal generated by the potentiometer 98, so that the transmission cylinder 62 of the piston will move in the opposite direction, that is, move into the power head. The moving speed of the housing is proportional to the angle at which the control rod 29 deviates from the original position shown in FIG. 6 .

FIG. 6 shows two return springs 102a and 102b which bear against the shaft 48 and generate a moment which tends the shaft 48 to return to the original position shown in FIG. 6 . Also shown is a combined flag/contact plate 104 which surrounds the shaft 48 and which may be in contact with the return springs 102a and 102b. When the return springs 102a and 102b are in contact with the flag/contact plate 104, an electrical connection can be made between them and a spring torque is applied to tend the shaft 48 to return to its original position. Also visible is a retaining spring 106, the function of which will be explained in more detail below. There is also a mark sensor 108, which is an optical detector that generates pulsed light and passes it through a gap, detects the pulsed light received on the other side of the gap and generates a digital signal to indicate whether the gap is blocked And prevent the transmission of optics.

Referring now to Figures 6, 7A and 7B, it can be seen that when the lever 29 is in the home position (see Figures 6 and 7A), the flag/contact plate 104 is positioned equidistant between the return springs 102a and 102b, the two The return spring applies a torque in the opposite direction to the lever 29, so that the lever 29 tends to be held in this home position, where the sign plate 105 of the sign/contact plate 104 is seated in the sign sensor 108 so that the sign sensor 108 A digital signal is generated to indicate that the rod 29 is in its original position. In this case, the control circuitry of the powerhead 22 can determine that manual movement of the control rod is not required to move the piston.

However, when the lever 29 is rotated away from its original position, such as when reaching the position shown in FIG. left its original location. In this case, the control circuit can read the electrical signal generated by the potentiometer 98 to determine the position of the rod 29 and cause the appropriate movement of the piston cylinder.

As previously indicated, the speed at which the piston cylinder moves is proportional to the extent to which rod 29 is displaced from its original position. At the same time, as the rod 29 rotates from the original position and increases the included angle, the mechanical structure of the return springs 102 a and 102 b can ensure that a return moment is applied to the rod 29 . Depending on the stiffness of the springs 102a and 102b and the range of motion of the rod 29, this return moment can be nearly equal at all deflection angles, or can increase or decrease with increasing deflection angles. If the return torque increases with increasing deflection angle, the operator can obtain additional piston speed feedback function.

As shown in FIG. 7B , when the lever 29 rotates in the opposite direction and increases the included angle, the sign plate 105 will eventually contact the stop spring 106 and the stop spring 106 will start to bend together with the return springs 102a and 102b. This results in an increased torque being applied and is perceived by the operator as a "stop" in the rotation of the manual motion control lever.

When filling a syringe, there is an ideal maximum velocity at which liquid can be drawn into the syringe without the formation of air bubbles due to the non-laminar flow of the liquid. When increasing the filling speed of the syringe, once this ideal speed is reached, the operator should get a feedback signal to make the syringe fill at the desired speed. The purpose of the stop spring 106 is to provide a mechanical feedback signal to the operator of the angle of deflection of the lever 29, which position corresponds to the desired filling speed. More specifically, when the rotation of the rod 29 brings the flag plate 105 into contact with the stop spring 106, the control circuit of the power head 22 can confirm that the piston drive cylinder is moved near the ideal filling speed. Thus, an operator wishing to prime near the desired speed can rotate the lever 29 until an increased detent torque is perceived, and then can hold the lever 29 in the detent position to prime.

The return spring 102 , flag/contact plate 104 and stop spring 106 not only function mechanically to provide a mechanical feedback signal to the operator, but also serve as electrical components in the control circuit of the powerhead 22 . Specifically, referring to FIG. 7C , each of these elements is a circuit element in a circuit to generate digital control signals required by the control circuit of the power head 22 .

As can be seen in Figure 7C, the return springs 102a and 102b with the flag/contact plate 104 in between and a resistor 110 are connected in series between a digital +5 volt supply and ground. A signal line 115 extends from between resistor 110 and return spring 102a and carries a logic voltage signal to indicate whether there is electrical contact between return springs 102a and 102b and flag/contact plate 104 . Under normal conditions, there is an electrical path from this line to ground to keep the voltage on line 115 at a low level. However, if any one of the springs 102a and 102b fails and is no longer in contact with the flag/contact plate 104, this electrical contact is broken and the voltage on the line 115 rises to a high level to Indicates that a return spring has failed. Failure of one return spring can be detected by monitoring the voltage on line 115, although the lever 29 will inadvertently deflect from its original position only if both return springs fail. Once such a failure is detected, a warning can be issued to the operator, or the manual motion control lever can be disabled.

Similar to the previous method, the stop spring 106 constitutes an electrical contact and is connected in series with a resistor 111 , and a stop signal line 116 protrudes from between the resistor 111 and the stop spring 106 . If the lever 29 is not rotated into the detent spring, the voltage on line 116 will rise to a high level to indicate that the lever 29 is not in the detent position. However, if the lever 29 is rotated such that the flag plate 105 contacts the detent spring 106, the voltage on line 116 will drop to a low level to indicate that the lever 29 has been rotated to the detent position. The signal on line 116 can be used in a variety of ways. For example, this signal can be used to correct a manual movement control lever so that the angle of rotation of the lever in the detent position corresponds to the desired filling speed. Alternatively, the signal can be used to prevent reverse movement of the piston cylinder at a speed higher than the desired filling speed. Finally, this signal can be used to establish a motion "dead band" where the piston cylinder will move at the desired fill speed while allowing the control rod to rotate beyond the "dead band" to produce a faster reverse speed.

Also shown in Figure 7C is a circuit detail of the sign sensor 108; a light emitting diode can be charged with a bias current through a resistor 113; The phototransistor causes a current to pass through resistor 112, thereby dropping the home signal on line 117 to a low voltage value to indicate that lever 29 is not in its home position. Otherwise, if light does not reach the base of the phototransistor in sensor 108, no current will flow through resistor 112 and the home signal on line 117 will rise to a high voltage value to indicate that lever 29 is in its home position . Accordingly, the control circuitry of powerhead 22 can use the signal on line 117 to determine whether to terminate movement of the piston cylinder.

Referring now to FIG. 8, the heating pad 42 according to the present invention employed in the powerhead 22 comprises an annular plastic section 118 and a molded plastic base. Plastic segment 118 contains a heating wire 120 made of resistive wire which generates heat when an electric current flows through the heating wire from a suitable power source. The heating wire 120 extends through the entire area of the annular plastic section 118. When the heating pad 42 is installed on the support 44, as shown in FIG. The wires in the cable 117 , the insulated cable 117 can be inserted into the control circuit of the power head 22 through the opening 51 ( FIG. 3 ), as shown in FIG. 2 . When the current starts from the power head, passes through the wires in the cable 117 and flows through the heating wire 120 , the heating wire 120 will evenly generate heat to heat the liquid in the injection tube in the pressure jacket 38 .

Ring segment 118 may be opaque, or may also be transparent or translucent. If the ring section 118 is transparent, the heating wire 120 can be seen (like in a car defroster or window screen), so that the operator can see through the ring section, the pressure jacket 38 and the wall of the injection tube. liquid. This facilitates the operator's primary line of sight to the interior of the injection tube during use, which would otherwise be blocked by the heating pad.

The base 119 of the heating pad is made of soft plastic and is molded over a resilient frame. The resilient backbone is shaped in the form of a disc 121 sized to slightly interfere with the struts 44 . As a result, the heating pad 42 can be press fit over the post 44 for common installation and removal (eg, for cleaning).

Please refer now to Figures 9 and 10 for an explanation of the integrated air detection system. Air detection module 122 is mounted on the end of strut 44 and is shaped to wrap around the distal portion of pressure jacket 38 and engage a collar 124a that surrounds the discharge neck of syringe 36 and projects outwardly. The air detection module 122 includes a light source 126 and a light sensor 127 at the point of contact with the collar 124a. Light sensor 127 is a commercially available circuit that includes a sensor 127 and an oscillator that generates a trigger signal to indicate when power should be applied to light source 126 to produce a light beam. The output of the sensor 127 is a digital signal to indicate whether a light beam is received by the sensor after the light source is triggered.

9 and 10 show the trajectory of the light beam emitted by the light source 126 . The light source 126 comprises an integral focusing lens, while the collar 124a on the discharge neck of the syringe 36 constitutes a second focusing lens. These lenses cooperate to transmit light from the light source 126 along a trajectory 129 toward the collar 124b located on the discharge neck of the syringe 36 . The inner shape of the collar 124b forms a corner reflector so that light from the light source 126 is reflected toward the sensor 127 after it hits the collar 124b.

As a result of this configuration, when the neck of the syringe 36 is filled with liquid, the light emitted from the light source 126 will pass through the trajectory in the neck of the syringe and be reflected back to the light sensor 127, as shown in FIGS. 9 and 10 . Trace 129 is shown. Therefore, in this condition, the sensor 127 will generate a digital signal indicating that light is received, which indicates that there is no air in the neck of the syringe. (The sum of the focal lengths of the light source 126 and the lens at the collar 124a is greater than the distance the light travels along the trajectory 129, ie greater than twice the distance between the collar 124a and the collar 124b).

However, if the syringe neck contains air or air bubbles, diffraction of light at the gas/liquid or gas/syringe boundary will cause the light to deviate from trace 129 in FIGS. 9 and 10 . Specifically, light rays entering the neck of the syringe 36 will travel along the trajectory 130 shown in FIG. 9 or the trajectory 131 shown in FIG. 10 . In either case, the presence of air bubbles will prevent the light emitted from light source 126 from being reflected at the syringe neck to light sensor 127, causing the light sensor to generate a signal indicating failure to receive light, which indicates that the light sensor has failed to receive light. Air trapped in syringe neck.

In order to obtain stable and repeatable results, the structure of the air detection module 122 can ensure that the light source 126 , the light sensor 127 are in close contact with the surface of the collar 124 a of the injection tube 36 . Specifically, the air detection module 122 has an inner frame 133 made of spring metal, which is wrapped by a soft elastic plastic 134 formed by molding. One end of a spring metal skeleton 133 is mounted on the strut 44 by a screw 135 (which is accessible through a space in the wrapping plastic 134). The other end of the frame 133 supports the air detection module, which includes a hard plastic molding 136 that supports the light source 126 and the light sensor 127 . Included in the molding 136 is a beveled section 137 sized to fit into a chamfer 138 at the opening of the pressure jacket 38 . The interaction of the sloped section 137 and the chamfer 138 can ensure precise positioning of the light source 126 and light sensor 127 relative to the pressure jacket 38 .

The neck of the syringe 36 is sized for a slight interference fit so that when the syringe 36 is inserted into the pressure sleeve 38, the collar 124a contacts and deflects the air detection module 122 slightly, thereby bending the spring backbone 133 and causing the Light source 126 and light sensor 127 apply a uniform force to collar 124a of syringe 36 . This applied force can ensure that the light emitted by the light source 126 enters the neck of the injection tube 36 with a good transmission path, and then enters the light sensor 127 from the neck of the injection tube 36 .

Turn now to FIG. 11A to explain the circuit details of the air detection module and other simulated electrical systems. Specifically, a commercially available synchronous detection circuit 140 is used in the air detection module, which includes an internal oscillator that can generate a trigger pulse on line 141, and the circuit 140 can be activated at the start of each trigger pulse. Simultaneously, a signal on line 142 indicating light received by light sensor 127 is detected. A higher order signal is generated on line 143 whenever light is detected at the same time as each trigger pulse. In the case where the circuit 140 according to the invention is used, the signal on line 143 indicates whether air is detected in the neck of the syringe 36 or not.

The control circuit of the power head 22 can control the light intensity applied to the air detector to control the sensitivity of the detector. To this end, the control circuit generates a pulse width modulated (PWM) digital signal on line 145 . The PWM signal is filtered by a low pass filter 146 to generate an analog control voltage for controlling an adjustable regulator 147 to generate a power supply signal for circuit 140 on line 148 .

In response to the trigger signal on line 141 , a PNP phototransistor 149 turns on, causing the power signal on line 148 to energize light source 126 . Thus, the voltage of the power signal on line 148 directly affects the intensity of the light produced by light source 126 .

In order for the control circuit to monitor possible malfunctions of the air detection circuit 140, the trigger signal on line 141 is connected to the base of a PNP phototransistor 149 through an LED in an optoisolator 150. Thus, once the trigger signal is activated, the phototransistor in optoisolator 150 is turned on, causing the voltage on line 151 to go low. Thus, if the synchronous air detection circuit 140 is functioning properly and generates a periodic trigger signal, pulses will appear on line 151 which can be detected by the control circuit to determine that the oscillator in circuit 140 is functioning properly.

FIG. 11A also shows an analog-to-digital (A/D) converter 152, which is installed in the power head control circuit to digitize the analog signals generated by various electrical components. For example, a potentiometer 98 (see FIG. 6 ) is connected to the shaft 48 of the fill/drain rod 29 . The wiper of the potentiometer is connected to a signal line 154 which carries an analog voltage indicating the rotational position of the fill/discharge lever shaft 48 . The opposite ends of the potentiometer are connected to a reference voltage and ground, respectively, so that the voltage on line 154 lies between these two limits and depends on the rotational position of the fill/drain lever 29 . Line 154 is connected to A/D converter 152, and converter 152 can convert the analog voltage on line 154 into a digital signal, which is placed on a "SPI" serial interface bus 156 for CPU (see Fig. 11B) Use, so that the CPU can determine the rotational position of the fill/drain lever 29 and react.

The air analog voltage is also input into the A/D converter 152 . Specifically, a monolithic accelerometer takes the form of an inclination sensor 158 to generate an analog voltage on line 159 to indicate the inclination angle of sensor 158 . (A monolithic accelerometer suitable for this purpose is available from Analog Devices of Norwood, Mass., part number ADXL05AH.) Sensor 158 is mounted on circuit board 55 and is used to generate an output voltage to indicate the relative The angle of inclination in the direction of Earth's gravity. This analog tilt signal is converted and input to the CPU for use, as described below, to control the display and other operating components of the powerhead 22 .

The third analog signal is generated by a linear potentiometer 160 whose brushes are mechanically connected to the piston cylinder 62 and move in response to the movement of the piston cylinder. Thus, the brush voltage on line 161 is an analog signal representative of the position of the drive cylinder, which is between the forwardmost position and the rearmost position. This signal is converted and input to the CPU for use in determining the position of the drive cylinder and other parameters such as the remaining volume of the syringe.

Two additional analog signals are generated by thermistors 163a and 163b, respectively, in series with biasing resistors to produce signals on lines 164a and 164b reflecting the thermistor temperature. The temperature measurement obtained from the thermistor is used to control the electrical power applied to the heating pad which is used to heat the liquid in the injection tube 36 . Specifically, the heating power applied to the syringe varies with the ambient temperature, which is measured by thermistors 163a and 163b, so that the liquid can be kept at a target temperature, such as 30 degrees Celsius.

Thermistors 163a and 163b are duplicates of each other, that is, they measure the same temperature and their measurements are compared to each other to ensure they are nearly equal. As a result, if a thermistor fails, it can be judged from the difference between the temperatures measured by the two thermistors, thereby preventing errors in temperature control.

Thermistors 163 a and 163 b may be mounted on circuit board 55 inside power head 22 . Alternatively, the thermistors 163a and 163b could also be mounted outside the vessel to ensure more accurate temperature readings, or both possibilities could be provided as an option, with built-in thermistors and, if used for replacement, external If the thermistor is connected to the power head 22, the built-in thermistor stops working.

Using thermistors 163a and 163b, powerhead 22 can control the heating power applied to injection tube 36 via heating pad 42, as described above. To accomplish this function, the CPU (see FIG. 11B ) generates a pulse width modulation (PWM) control signal on line 166 to control the heating power applied to the heating wire 120 of the heating pad. Specifically, the PWM control signal on line 166 is filtered by a low pass filter 167 to produce an analog control signal for controlling adjustable regulator 168 . The signal output by regulator 168 on line 169 is a variable voltage that is applied to heating pad heating wire 120 to cause heating wire 120 to generate heat.

A sense amplifier 170 which filters and conditions the voltage applied to the heating wire 120 produces an analog output signal on line 171 which is proportional to the voltage applied to the heating wire 120 .

A detection resistor 173 is connected in series with the heating wire 120 so that the current in the heating wire 120 flows through the detection resistor 173 , and the voltage generated on the detection resistor is proportional to the current flowing through the heating wire 120 . The resistance of the detection resistor is much smaller than the resistance of the heating wire 120 , so the small voltage drop across the detection resistor 173 is much smaller than the voltage drop across the heating wire 120 .

The voltage drop across sense resistor 173 is amplified and filtered by a gain/filter circuit 172 to produce an analog voltage on line 174 which is proportional to the current through heating wire 120.

Lines 171 and 174 are connected to A/D converter 152, which converts the voltage on lines 171 and 174 into digital signals that can be read by the CPU. In this way, the CPU can determine the current and voltage drop in the heating wire 120 , and use these values to determine the output heat of the heating wire 120 . This allows the CPU to perform closed-loop control of the heat output of the heating pad, as discussed below in conjunction with FIG. 12 .

Please refer now to FIG. 11B to understand how the CPU of the powerhead 22 is connected. CPU 175, which may be a 68332 microprocessor, available from Motorola Corporation, controls data and address bus 176, which connects CPU 175 to random access memory (RAM) 178 and a flash memory 177. CPU 175 also controls an SPI serial interface bus 156 for communicating with A/D converter 152, display 30 and a monitoring microcontroller 192. The CPU 175 also includes an RS-422 serial port 179 for connecting the CPU 175 to the power pack (see Figure 11C).

CPU 175 includes a set of digital data input lines to monitor the operation of powerhead 22. In particular, CPU 175 receives a stop signal on line 116, a safety signal on line 115, and a home signal on line 117, so that CPU 175 receives input about the operating state of the aforementioned manual motion control lever Signal. The CPU 175 also receives the air bubble signal on line 143 so that the CPU 175 can detect air in the neck of the syringe and take appropriate action, and also receives the bubble detection oscillator signal on line 151 as previously described , to confirm whether the oscillator in the air detection module 122 works normally. In addition, the CPU 175 also receives the output signal of the mark sensor 58, so that the CPU 175 can determine whether the panel is locked on the power head 22. In addition, the CPU 175 receives digital signals from the three magnetic detectors 56a, 56b and 56c which can indicate which of several available panels is installed on the powerhead 22 so that the CPU 175 can adjust it accordingly operation.

The CPU 175 also receives digital signals from a parallel rotary encoder 182 which generates pulse signals on lines 183a and 183b to indicate the rotation of the piston drive train. These pulses are used by the CPU 175 to determine the movement of the piston cylinder. Lines 183a and 183b are also connected to the power pack (see Figure 11C) so that the power pack's CPU can close loop control the piston movement by counting pulses from the encoder and comparing the rate of pulses received to the desired rate. A closed-loop control approach is proposed in US Patent No. 4,812,724, which is hereby incorporated by reference in its entirety.

The CPU 175 also generates a number of digital control signals, including those previously mentioned, for example, the bubble detector power PWM signal on line 145, the heating pad power PWM signal on line 166, both of which are controlled by the CPU 175. pulse width modulation to generate the desired power level. CPU 175 also generates an output signal on line 187 to ignite a light-emitting diode in indicator light 46 (FIG. 2), which is used to indicate the status of the syringe. Additional signals output on the SPI serial interface bus 156 are used to control the display 30 .

The CPU 175 utilizes the aforementioned input and output signals to implement basic control of the powerhead 22 through software that resides in the CPU 175 or is read from the RAM 178. As previously mentioned, CPU 175 is also connected to a microcontroller 192 by SPI serial interface bus 156, and microcontroller 192 is used as a monitor to monitor the work of CPU 175 to ensure that there are no software or hardware failures. (microcontroller can be a one-chip microcontroller, can be purchased from Microchip Technologies company, article number is no.PIC16C63) microcontroller 192 receives the signal that is used for displaying CPU 175 working state by bus 156, to complete its this function.

Specifically, the CPU 175 displays the operating status of the CPU 175 via the bus 156, i.e., whether the CPU 175 requires piston movement, whether the required movement is in response to manual or automatic (program) control, and other possible special information, such as the required speed of movement, etc. The monitoring microcontroller 192 reads this status information on the bus 156 and compares this information with the significant digital input signals from the powerhead 22 to ensure that they agree with each other.

For example, microcontroller 192 receives a safe signal on line 115 and a home signal on line 117 . If these signals indicate that the manual control lever is in the home position, the CPU 175 will not generate movement under the manual control lever. If a spring fails (will be shown by a signal on line 115), this will be shown in the status of the CPU 175. Like this, in this state, microcontroller 192 reads information from bus line 156, to ensure that CPU 175 can not take the action that is incompatible with the signal that manual joystick sends.

As a second example, microcontroller 192 receives the signal output by encoder 182 on lines 183a and 183b. Microcontroller 192 detects these signals to determine whether the piston cylinder is moving, thereby ensuring that the cylinder can only move if the state of the CPU 175 indicates that the cylinder should move, and not in other states. Also in this regard, it should be noted that the microcontroller 192 receives the door mark signal from the door mark sensor 58 . If the signal indicates that the door of the power head 22 is not in the locked position, the CPU 175 cannot command the piston cylinder to act, and the microcontroller 192 will determine this by detecting that no pulses are sent from the encoder 182.

Please refer now to FIG. 11C for a further understanding of the interaction of the powerhead 22 , powerpack 26 and console 24 . Specifically, all comprise a CPU 175,192,194 in the power head 22, the power pack 26 and the console 24. These CPUs realize the control of the injector through the interaction of external interfaces. For example, the piston cylinder can be controlled by the lever 29 on the powerhead 22 (as previously discussed), or it can be automatically controlled by the operator using the touch screen 32 of the console 24 (using the CPU 194) to enter the injector program and then start the injection program. . Injection parameters, such as motor speed and injection volume, can be generated by the CPU 194, which communicates with the CPU 192 of the power pack to implement these program-controlled actions. Additionally, an automatic injection process can be accomplished using the touch screen 32, or an injection process can be initiated using a manual switch or OEM remote trigger connected to the power pack 26. In either case, a suitable one of the CPUs 192 and 194 will generate an enable signal to begin automatic injection.

As previously mentioned, the CPU 175 of the power head is connected with a monitoring microcontroller 192, and the monitoring microcontroller 192 is used to monitor the state of the CPU 175 to ensure that the action of the CPU 175 is consistent with the output signal from the power head 22. Likewise, CPUs 192 and 194 are connected to supervisory microcontrollers 196 and 198, respectively. Both supervisory microcontrollers monitor the activity of the connected CPUs 192 and 194 to ensure consistent trouble-free operation.

The communication between the monitoring microcontrollers 192, 196 and 198 is parallel to the communication between the CPUs 175, 192 and 194. Specifically, the three monitoring microcontrollers exchange the state information they get from the connected CPUs with each other to ensure that the three CPUs are in the same working state, eg, manual motion, automatic motion, no motion, etc. In addition, each microcontroller receives external input signals to ensure that state transitions that should occur actually occur. In this manner, microcontroller 196 receives a manual or OEM trigger signal so that microcontroller 196 can determine when an automatic injection procedure is initiated. Microcontroller 198 receives input signals from touch screen 32 so that it can also determine when the automatic injection process is initiated. Other monitoring functions may also be implemented to ensure correct and consistent operation of the CPUs 175, 192, and 194.

As mentioned above, the CPU 175 of the power head transmits a control signal to the power group 26, requesting a drive cylinder action. The power pack 26 includes a motor servo control circuit, which is used to generate a suitable power signal on the line 200 to drive the motor 63 and realize closed-loop control of the motor movement according to the encoder pulse on the line 183 .

In a fault condition, each monitoring microcontroller can stop any movement of the piston cylinder by cutting off power to the motor 63 by disabling the hardware, namely the switch 202 connected in series in the power line 200 . This hardware shutdown ensures that the respective monitoring microcontrollers are able to prevent incorrect fluid injections in fault conditions.

Please refer to Fig. 12 now, to explain the control function of the heating pad of CPU 175 of power head. To realize the heating pad control, the CPU 175 first measures the outside temperature through the first and second thermistors 163a and 163b (steps 204 and 206). (As part of these steps, the CPU 175 first consults a calibration table to convert the thermistor voltage to a corresponding temperature.) The CPU 175 then determines whether the temperature readings are consistent (step 208). If not, then one of the thermistors is faulty, a warning signal will be generated and the heating pad will be disabled (step 210).

If the thermistor temperature readings agree, the CPU 175 will operate to determine a desired heating pad output power level P _OUT based on the measured ambient temperature T _AMBIENT (step 210). A thermal model was used to calculate the power required to maintain the liquid temperature at 37°C. The power can be varied according to this thermal model within the ambient temperature range of 0°C to 32°C. When the outside temperature exceeds 32°C, the heating pad will be turned off to prevent the liquid from overheating. When the outside temperature is lower than 0° C., the power generated by the heating pad is limited to 8 watts to prevent the heating wire 120 in the heating pad from overheating. A simple thermal model is the linear model, in which the output power is determined by the formula: P _OUT = B-AT _AMBIENT , where B and A are empirically calculated correction and amplification factors, respectively, and P _OUT is limited to 8 watt. Other models, especially nonlinear models, may also be used.

To generate the desired output thermal energy, CPU 175 generates a PWM signal on line 166 (FIG. 11A) per duty cycle (step 212). The liquid in the syringe is heated from the first duty cycle selected.

After this PWM duty cycle produces, CPU 175 will be used for displaying the voltage and the electric current (step 214 and 216 steps) that are applied on the heating wire 120 from reading (by A/D converter 152) on lines 171 and 174. Multiplying these values gives the actual output power of the heating pad, which is compared to the desired output power calculated earlier (step 218). If the current output power is substantially equal to the required power, the current PWM duty cycle is correct, and the CPU 175 will return to step 204 to re-measure the outside temperature, thereby continuously controlling the heater output power. However, if the heater output power is too large or too small, the CPU 175 will first perform step 220, and adjust the PWM duty cycle to change the output heating power as required (if it is too large, the duty cycle is shortened, if it is too small, it is increased Working period). Afterwards, the CPU 175 will return to step 204 to re-measure the outside temperature, thereby continuously controlling the heater output power.

This temperature control method can compensate the temperature change of the liquid caused by the external temperature change, thereby ensuring accurate control of the liquid in the injection tube 36, reducing the heat to the injection object caused by the injection liquid not being at the required temperature. shock.

Please refer now to Figures 13A-13C to understand the operation of the reversible display. Specifically, as previously mentioned, the CPU 175 receives a signal from the inclination sensor 158 for displaying the inclination angle of the power head 22 relative to the direction of gravity of the earth. The CPU 175 repeatedly samples from this signal to determine the tilt angle of the powerhead 22 relative to the direction of Earth's gravity (direction 122). All possible rotation angles are divided into six operating regions, as shown in Fig. 13A.

Zone 1 is the "fill" zone; the powerhead 22 should be at an angle in this zone when filling the syringe. When the power head 22 is at an angle in zone 1, or in the adjacent zone 2A or 2B, the power head allows manual movement of the piston drive cylinder in the forward or reverse direction so that the operator can fill the syringe Or to expel air from the syringe after initial priming. A wide range of speeds of movement can be obtained by manually moving the control lever, allowing rapid filling of syringes. When the powerhead 22 is in zone 1, 2A or 2B, programmed injection operations are inhibited; thus, when the powerhead 22 is in the upper right position, the operator cannot initiate an injection into a subject according to the preprogrammed injection protocol. This minimizes the chance of accidentally injecting air into the subject.

Zone 4 is the "injection" zone. When the power head 22 is tilted into this region, the programmed injection operation can begin. Additionally, a manual motion control lever 29 can be used to move the piston cylinder in either the forward or reverse direction; however, the range of speeds of motion produced by the manual motion control lever is relatively narrow compared to areas 1, 2A or 2B. In this way, a finely tuned controlled liquid injection operation can be achieved by manually moving the control lever.

Areas 3A and 3B can also be used for injection. If a hypertrophied patient or other obstacle prevents the operator from rotating the powerhead to the fully downward position in zone 4, the powerhead can adopt the tilt angles in zones 3A and 3B. However, operating in areas 3A and 3B is discouraged due to the possibility of injecting air into the subject, and thus the operator cannot operate in these two areas without accessing an overloaded software via the console touch screen 32 . Before entering the overload software, the display 30 will blink and the syringe will not be able to perform programmed injections. Once the overload software is entered, the display will stop flashing and the syringe can be programmed for injection. In addition, in zone 4, the manual movement control lever 19 can be used to move the piston cylinder in a narrow range of moving speeds in the forward or reverse direction, so that finely tuned control of fluid injection can be achieved by manual movement of the control lever. (or discharge) operation.

The various angular areas mentioned above also relate to display orientation. Specifically, as shown in Figures 13B and 13C, the display 30 of the powerhead 22 is a segmented display and the segments can be illuminated to display injection information such as the amount injected, the amount remaining, and the current flow rate. The segments are arranged so that the above-mentioned information can be displayed both in a first orientation (see FIG. 13B) and in a second orientation (see FIG. 13C).

When the angle of the power head 22 is in the area 1, 2A or 2B, the CPU 175 in the power head 22 drives the display 30 to generate the display orientation, so that the display elements adopt the mode shown in FIG. 13C. Additionally, in area 3A, 3B or 4, CPU 175 drives display 30 to produce the display orientation shown in FIG. 13B. As a result, the information displayed on the display 30 is always upward relative to the operator for ease of use of the display. (There is a blocking function in the direction of the border between the regions shown in Figure 13A to prevent inadvertently staying between the regions).

While the invention has been illustrated by illustration of various embodiments, and these embodiments have been described in considerable detail, it is the applicant's intention not to limit the scope of the appended claims or to limit them in any way to these detailed in description. Additional advantages and modifications may suggest to those skilled in the art. For example, the control circuit may make an injection pressure or filling volume proportional to the angular displacement of the control rod 29 relative to the original position, rather than a speed proportional to the degree of rotation. Bubble detection can be accomplished with an ultrasonic source and an ultrasonic detector attached to the neck of the syringe. In this case, air can be detected because sound attenuation is more severe in air than in liquid. Air bubble detectors can be mounted elsewhere in the syringe instead of the neck. In addition, an air bubble detector can be used with the powerhead control circuit to enable automatic syringe filling functions, for example, to detect when air is expelled from the syringe after filling. Additionally, a full pixel display may be employed in the powerhead 22 and controlled by the powerhead CPU to produce various display orientations. The invention in its broadest aspects is therefore not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described herein. Accordingly, departures may be made from the specific details described above without departing from the spirit and scope of the general inventive concept of the present invention.

Claims (38)

1. A syringe for injecting a liquid from a syringe into an animal subject, comprising an air detector for detecting air flow from said syringe to said animal subject, the syringe comprising: a piston cylinder, a motor for moving the piston drive cylinder, a syringe holder for securing a syringe to position a syringe relative to the syringe such that the piston drive cylinder engages a piston and moves the piston within the syringe, an air detector positioned apart from the piston drive cylinder to engage a wall of the syringe, the air detector including a signal source for emitting a signal passing through the syringe through the liquid or The air detection signal of the air also includes a signal receiver for detecting the air detection signal transmitted through the liquid or air in the injection tube, if the air detection signal received by the signal receiver shows that the injection air is present in the pipe, the air detector produces a warning signal, and a control circuit that controls the motor to move the barrel and plunger to inject the liquid in the syringe, and in response to the warning signal, the control circuit prevents movement of the barrel to prevent air from being trapped Injected into said subject. 2. The syringe of claim 1, wherein said signal source is a light emitting diode and said air detection signal is an electromagnetic signal. 3. The syringe of claim 1, wherein said signal source is an ultrasonic transmitter and said air detection signal is an acoustic signal. 4. The syringe of claim 1, wherein said syringe further comprises a housing, said syringe mountably extends outside said housing, and said syringe further comprises a An outwardly protruding pillar on which the air detector is mounted. 5. The syringe according to claim 4, further comprising a cylindrical barrel, a piston compactly installed in said cylindrical barrel in a slidable manner, a discharge nozzle having liquid communication capability with said cylindrical barrel, and a an overhang on said discharge spout, Wherein, when the syringe is installed in the syringe, the extension section will be pressed against the detector so as to transmit the body detection signal to the row of the syringe. in the liquid mouth. 6. The syringe of claim 5, wherein said overhanging section of said syringe is a circumferential ring surrounding said spout. 7. The syringe according to claim 5, wherein said signal source is a light emitting diode, and said air detection signal is an electromagnetic signal, and said syringe is shaped so that only when said discharge nozzle contains When liquid is present, it is capable of substantially reflecting said electromagnetic signal originating from an inner wall of said discharge nozzle towards said signal receiver. 8. A syringe for mounting to a syringe containing an air detector, the syringe comprising: a cylindrical barrel, a piston slidably mounted compactly within said cylindrical barrel, a drain nozzle having liquid communication capability with said barrel, and an overhanging section located on said spout, said section being shaped to substantially transmit an air detection signal received from outside said section to inside said spout so that said The air detection signal reflects back from an inner wall of the spout and passes through the segment. 9. The syringe of claim 8, wherein said overhanging section of said syringe is a circumferential ring surrounding said spout. 10. The syringe of claim 9, wherein said ring has an arcuate cross-section and forms a lens to focus light received from the outside of said ring to said spout of said syringe middle. 11. A syringe for injecting a liquid from a syringe into an animal subject, comprising a manual movement control lever for controlling movement of said syringe, the syringe comprising: a piston cylinder, a motor for moving the piston drive cylinder, a syringe holder for securing a syringe to position a syringe relative to the syringe such that the piston drive cylinder engages a piston and moves the piston into or out of the syringe, a control circuit that controls the motor to move the barrel and piston to inject the liquid in the syringe, and a manual motion control lever consisting of a lever that can be moved between a home position and a forward and reverse position, In response to movement of the rod to the forward position, the control circuit moves the plunger cylinder into the syringe to expel fluid from the syringe, and in response to movement of the rod to the reverse position, The control circuit will move the plunger cylinder out of the syringe to draw liquid into the syringe. 12. The syringe according to claim 11, wherein said rod is mounted on a hinge in said syringe and further comprises return springs respectively located on opposite sides of said rod so that when said rod is moved from said When the home position is rotated away, the return spring is bent. 13. The syringe according to claim 12, further comprising a rotation detector fixed on said hinge shaft, which rotates together with said rod to detect the rotation angle of said rod and generate a rotation angle signal, wherein, as a In response to the rotational angle signal, the control circuit moves the piston drive cylinder at a speed related to the rotational angle signal. 14. The syringe of claim 13, wherein said control signal causes said piston drive cylinder to move at a rate proportional to said angle of rotation of said rod. 15. The syringe of claim 13, wherein said rotation detector is a rotary potentiometer. 16. The syringe according to claim 12, further comprising a rotation detector fixed on said hinge shaft, which rotates together with said rod to detect the rotation angle of said rod and generate a rotation angle signal, wherein, as a In response to the rotational angle signal, the control circuit moves the piston drive cylinder to generate an injection pressure relative to the rotational angle signal. 17. The syringe of claim 12, wherein said return spring and said rod are electrical contacts, and further comprising a safety circuit that generates a signal indicating the presence or absence of contact between said return spring and said rod. Safety control signals for electrical contacts, the control circuit is responsive to the safety control signal, Thus, a failure of a return spring can be electrically detected by the control circuit. 18. The syringe according to claim 12, further comprising a retaining spring positioned relative to said lever such that when said lever is rotated to an angle between a position and an original position exceeding a predetermined angle, said lever The stop spring engages the rod, the stop spring creating an additional resistive moment in the direction opposite to the rotation of the rod beyond the predetermined angle from the original position. 19. The syringe of claim 18, wherein said stop spring is positioned relative to said lever such that said stop spring engages said lever when said lever is rotated toward a reverse position. 20. The syringe of claim 19, wherein said detent spring and said lever are electrical contacts, and further comprising a detent circuit that generates a signal for displaying said return spring and said lever stop signal for the presence or absence of electrical contact between In response to the detent signal, the control circuit will move the plunger cylinder out of the syringe to draw liquid into the syringe at the predetermined recommended maximum velocity. 21. A syringe for injecting liquid from a syringe into an animal subject, the syringe comprising: a piston drive cylinder; an electric motor for moving the piston cylinder; a syringe holder for securing a syringe to position the syringe relative to the syringe such that the piston drive cylinder engages a piston and moves the piston into or out of the syringe; an electronic display for displaying information about the action and status of operation of the injector, and the display can display information in at least a first and a second orientation; an inclination sensor that generates an inclination angle signal indicative of the inclination angle of the syringe relative to the direction of gravity of the earth, and A control circuit, which is connected to the motor, and controls the motor to move the piston drive cylinder and the piston to inject the liquid in the syringe, and the control circuit generates display information and transmits the display information to the the display, Wherein, the display is responsive to the tilt angle signal, and for a first range of values of the tilt angle signal, the display displays information in a first orientation, and for a second range of values of the tilt angle signal, the display displays information in a second orientation. Azimuth display information. 22. The syringe of claim 21, wherein said display includes display elements therein positioned such that the display produces numbers in either an upward orientation or a downward orientation. 23. A syringe according to claim 22, wherein said display is a light emitting diode display. 24. A syringe according to claim 21 wherein said display is a matrix of uniformly shaped pixels which are selectively activated and combined to form images or characters on the display. 25. The syringe of claim 21, wherein said control circuit determines a speed of movement of the motor based on the tilt angle signal. 26. The syringe according to claim 25, wherein said control circuit operates said motor when said tilt angle signal indicates that said syringe is tilted upward and a discharge nozzle of said syringe is positioned above said syringe at a first speed; and when the tilt angle signal indicates that the syringe is tilted downward and a discharge nozzle of the syringe is positioned below the syringe, the control circuit operates the motor at a speed lower than the first speed. One speed second speed operation. 27. The syringe according to claim 21 , further comprising a manual movement control lever coupled to said control circuit for generating a movement signal, said control circuit responsive to said movement signal to cause said motor to move along said The direction shown by the motion signal, the control circuit also responds to the stored program to automatically control the operation of the motor to complete the injection, Wherein, the control circuit responds to the tilt angle signal to prevent the motor from automatically operating according to the stored program, unless the tilt angle signal indicates that the syringe is tilted within a predetermined range of an included angle relative to the direction of gravity of the earth Inside. 28. The injector of claim 21 , wherein said control circuit is further responsive to said tilt angle if said tilt angle signal indicates that said syringe is tilted within a predetermined range of angles relative to the direction of gravity of the earth. signal, thereby generating a display message to warn the operator not to administer the injection. 29. A syringe for injecting liquid from a syringe into an animal subject, the syringe comprising: a piston drive cylinder; an electric motor for moving the piston cylinder; a syringe holder for securing a syringe to position the syringe relative to the syringe such that the piston drive cylinder engages a piston and moves the piston into or out of the syringe; an inclination sensor that generates an inclination angle signal indicative of the inclination angle of the syringe relative to the direction of gravity of the earth, and A control circuit is connected with the motor, and controls the motor to move the piston drive cylinder and the piston to inject the liquid in the syringe, and the control circuit determines a moving speed of the motor according to the tilt angle signal. 30. The syringe according to claim 29, wherein said control circuit operates said motor when said tilt angle signal indicates that said syringe is tilted upward and a discharge nozzle of said syringe is positioned above said syringe at a first speed; and when the tilt angle signal indicates that the syringe is tilted downward and a discharge nozzle of the syringe is positioned below the syringe, the control circuit operates the motor at a speed lower than the first speed. One speed second speed operation. 31. The syringe according to claim 29, further comprising a manual movement control lever connected to said control circuit and adapted to generate a movement signal, said control circuit responsive to said movement signal to cause said motor to move along said The direction indicated by the motion signal, the control circuit also responds to the stored program to automatically control the operation of the motor to complete the injection, Wherein, the control circuit responds to the tilt angle signal to prevent the motor from automatically operating according to the stored program, unless the tilt angle signal indicates that the syringe is tilted within a predetermined range of an included angle relative to the direction of gravity of the earth Inside. 32. The injector according to claim 29, wherein said control circuit is further responsive to said tilt angle if said tilt angle signal indicates that said syringe is tilted within a predetermined range of angles relative to the direction of gravity of the earth signal, thereby generating a display message to warn the operator not to administer the injection. 33. A syringe for injecting liquid from a syringe into an animal subject, comprising: a container, a piston drive cylinder mounted in said housing, a panel mounted on an outer surface of the housing for receiving a removable panel for positioning a syringe relative to the syringe housing so that the piston drive cylinder can engaging a plunger and moving the plunger into or out of said syringe, said panel containing one or more magnetic field energy sources, the presence or orientation of said magnetic field energy sources in a given panel indicating said panel the properties and type of a syringe mounted on said syringe through said panel, one or more magnetic conductors of magnetically permeable material extending from the panel and mounted within the enclosure, the magnetic conductors being positioned such that they transmit the one or more magnetic field energy sources The magnetic field energy is transferred into the enclosure, and a control circuit, which is connected to the motor and controls the motor to move the barrel and piston to inject the liquid in the syringe, the control circuit includes one or more magnetic field detectors, the a magnetic field detector located inside the containment adjacent to the magnetic conductor to detect a magnetic field transmitted into the containment through the magnetic conductor, the control circuit responsive to the magnetic field detector based on the The presence or orientation of magnetic field energy detected by the magnetic field detector identifies a panel mounted on the injector and operates the motor in a manner appropriate to the type of syringe through which the syringe may pass. mounted on the syringe. 34. A syringe for injecting liquid from a syringe into an animal subject, comprising: a piston cylinder, a motor for moving the piston drive cylinder, a syringe holder for securing a syringe to position the syringe relative to the syringe such that the piston drive cylinder engages a piston and moves the piston into or out of the syringe, a manual motion control lever for generating a motion demand signal indicating that the operator desires said piston cylinder to move, an encoder, which is connected to the motor to generate a motion signal for displaying the motion of the piston drive cylinder, a motor control circuit, which is connected to the motor, the manual movement control rod and the encoder control the motor to move the barrel and piston to inject the liquid in the syringe, the motor control A circuit responds to the motion request signal to instruct the motor to move the barrel and piston, and the motor control circuit also generates a status signal for displaying the working status of the motor control circuit, and passes the status signal through the a monitor interface of said motor control circuit, said status signal at least indicating whether said motor control circuit responds to said motion request signal by operating said motor, a motor monitoring circuit connected to the motor control circuit, the encoder and the monitor interface of the motor control circuit to monitor the motion request signal, the motion signal and the status signal, the The motor monitoring circuit is used to determine that the state signal is consistent with the motion request signal and the motion signal. This determination process needs to at least determine: when the motion request signal shows that the motor is expected to run, and the state signal When the motor control circuit is shown to operate the motor in response to the motion request signal, the motion signal indicates that the motor is operating in accordance with the motion request signal. 35. The syringe of claim 34, wherein said motor monitoring circuit generates a warning signal if said status signal is inconsistent with said motion request signal and said motion signal. 36. The syringe of claim 35, wherein said motor prevents further movement of said piston drive cylinder in response to said warning signal when said motor monitoring circuit generates said warning signal. 37. The syringe according to claim 34, further comprising a console enabling an operator to program a desired movement of said piston cylinder, a console control circuit coupled to said console for acquiring and storing an operator programmed desired movement, The console control circuit generates an exercise request signal based on the stored program of desired exercise. 38. The injector according to claim 37, wherein said console control circuit generates a console status signal for displaying the operating status of said console control circuit, and further comprises a console monitor circuit which communicates with said communicating with the console control circuit to obtain the console status signal once the console control circuit has generated the motion demand signal to verify that the motor control circuit is responsive to the motion demand signal as determined by the motor monitoring circuit , the console monitor circuit also communicates with the motor monitor circuit.

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