JP2001055984A - Medical injector head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medical injector head with a safety means for stopping a piston, when detected to be malfunctioned. SOLUTION: This medical injector head has a sensor part 121 and a malfunction detection part. The sensor part includes a collar 114 and a microswitch 115. The collar which is fixed to a piano wire 113 is moved together with a piston by a movement transmission part 122 and then located at a given space from the piston at the time when it is moved back. When malfunction occurs particularly during manual operation, the collar contacts the microswitch to cause the stop of the piston, when detected to be malfunctioned.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical injector head, and more particularly to a medical injector head provided with a safety means for detecting a malfunction.

[0002]

2. Description of the Related Art In recent years, various devices have been developed as devices for inspecting the functions of the human body. One of them is a circulatory organ X-ray diagnostic apparatus for diagnosing the circulatory function of the human body. This circulatory organ X-ray diagnostic apparatus is equipped with a medical injector head for injecting a contrast agent into a patient, as one of instruments for performing a procedure required for X-ray diagnosis.

[0003] Here, a conventional medical injector head will be described. 11 and 12, the medical injector head 100 has a piston 1 inside.
Syringe 10 provided with 0b is attached. The piston 10b is connected to a plunger 104 provided on the injector head 100. By moving the plunger 104 forward, the contrast agent sealed in the syringe 10 is injected into the patient. On the other hand, the plunger 104
Is retracted, the contrast agent can be sealed in the syringe 10.

[0004] At the rear end of the plunger 104, a ball screw 106 is mounted. By rotating the ball screw 106 by the motor 110, the plunger 104 can be moved forward or backward.

A position plate 112 is mounted on the plunger 104. This position plate 112 is linked to the movement of the plunger 104. The four corners of the position plate 112 are guided by guide rods 111 provided in the main body frame.

The motor 110 is provided with a potentiometer 108 for detecting the position of the plunger 104. A plunger position signal S3 is sent from the potentiometer 108 to the main body control unit 100C. The plunger position signal S3 is a so-called feedback signal. Thus, the position of the plunger 104 can be accurately controlled.

[0007] A motor 110 is provided from the main body control unit 100C.
, A motor drive voltage S2 is output. When the injection amount of the contrast agent is input to the control panel 100B, a predetermined signal is sent from the control panel 100B to the main body control unit 100C, and the motor drive voltage S2 is output from the main body control unit 100C to the motor 110. .

By the way, when the contrast agent sealed in the syringe 10 is injected into a patient, the contrast agent is injected into the piston 10b.
Therefore, a relatively large pressure acts on the syringe 10. In general, the syringe 10 is made of a disposable member, and thus has insufficient pressure resistance, and the syringe 10 tends to expand.

Therefore, even when the movement of the piston 10b is completed, the contrast agent exceeding the predetermined amount and the predetermined time continues to flow out of the distal end of the syringe 10.

Therefore, in order to prevent this, the piston 10b is moved to the rear end side by a distance corresponding to the increased amount of the contrast agent exceeding a predetermined amount. Main unit control unit 100C
Is connected to a reverse rotation control unit 100D that outputs a signal for moving such a piston 10b to the rear end side.

Next, the operation of the above-described medical injector head will be specifically described. First, referring to FIG. 13, contrast agent 1 is sealed in syringe 10 mounted on medical injector head 100. Next, referring to FIG. 14, in order to inject a predetermined amount (Q) of the contrast agent into the patient, the plunger 104 is moved by a predetermined amount (Q) and an arbitrary increase amount (+ α).
It is moved by a distance corresponding to the piston 10b L ₁
Let go forward. Here, the position of the piston 10b in the state shown in FIG. 13 and B _1, the position of the piston 10b in the state shown in FIG. 14 and B _2.

Thereafter, in order to reduce the pressure acting on the syringe 10, as shown in FIG.
Retracting by an arbitrary amount of increase (-.alpha.) component in the direction indicated by the arrow D ₂ to. The position of the piston 10b at this time is B _3. Thus, by retracting the piston 10b by a predetermined amount, the pressure acting on the syringe 10 is reduced, and a predetermined amount (Q) of the contrast agent can be injected into the patient from the tip of the extraction unit 10a. it can.

Such a series of injection operations is performed in either a manual operation mode or an automatic operation mode. In the case of manual operation, the person in charge performs ON / OFF operation from the control panel 100B to drive the motor 110.

On the other hand, in the case of automatic operation, for example, the motor 11 is set as set based on a predetermined program previously installed in the main body control unit 100C or the like.
0 drives.

A conventional medical injector head is constructed and operates as described above.

[0016]

As described above, the conventional medical injector head is operated in either a manual operation mode or an automatic operation mode. In the case of manual operation, the person in charge performs a series of injection operations while checking the surroundings of the medical injector head, the patient, etc., so if a failure occurs in the medical injector head,
The injection operation can be stopped immediately.

However, in the case of automatic operation, the following problems are assumed. As described above, in order to reduce the pressure acting on the syringe 10, the piston 1
0b is retracted by an arbitrary increment (-α). At this time, if a malfunction occurs in the main body control unit 100C due to, for example, a runaway of the installed program or the like, the piston 10b may be retracted by more than an arbitrary increment (−α).

In this case, the patient's blood is to be sucked from the distal end of the syringe 10 attached to the patient.
There can be problems that can adversely affect the patient.

Further, when the next injection operation is performed while blood is sucked into the distal end portion of the syringe 10, the amount of the contrast agent decreases by the amount of the sucked blood, and a predetermined amount of the contrast medium is reduced. Another problem is that the agent cannot be injected into the patient.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and when the piston moves backward beyond a predetermined distance due to a malfunction when the piston is moved backward, the movement of the piston is prevented. It is an object of the present invention to provide a medical injector head that can stop the operation.

[0021]

SUMMARY OF THE INVENTION A medical injector head according to the present invention has a tubular body having an extraction portion at the front end and an opening at the rear end, and a front end and a rear end of the body. A medical injector head mounted with a syringe portion having a piston movably provided between the body portion and a piston for forming a space for enclosing a liquid inside the body portion, wherein a piston driving means and a first piston are provided. Control means, second piston control means, and safety means are provided. The driving means gives the piston a movement toward the front end or the rear end. The first piston control means outputs a signal for moving the piston to the distal end side by a predetermined distance to the piston drive means in order to send out the liquid from the extraction part in a state where the liquid is sealed in the syringe part, to the piston drive means. . The second piston control means moves the piston to the rear end side by a predetermined distance in order to reduce the pressure of the liquid applied to the syringe after the first piston control means moves the piston by a predetermined distance. When the piston attempts to move beyond the predetermined distance due to a malfunction when the piston is moved rearward by a predetermined distance by the second piston control means, the safety means detects the malfunction and moves the piston. Is output to the piston driving means.

According to this medical injector head,
The first piston control means controls the piston to move toward the distal end by a distance corresponding to an arbitrary increment of the predetermined amount of liquid, and the second piston control means moves the piston to the arbitrary increment of liquid. By controlling the movement to the rear end side by a corresponding distance, the pressure acting on the body is reduced, and a predetermined amount of liquid is injected into the patient from the extraction part of the body. At this time, if the piston attempts to move to the rear end side beyond a distance corresponding to an arbitrary increase due to a malfunction, the safety means detects the malfunction and immediately stops the movement of the piston. As a result, the patient's blood is not sucked by the medical injector head, and the patient is not adversely affected. Further, the next injection operation is not performed while the blood is being sucked, and a predetermined amount of liquid can be injected into the patient.

Preferably, the safety means has a sensor unit for detecting a malfunction and a signal processing unit for outputting a signal for stopping the piston driving unit based on a signal sent from the sensor unit. The sensor section has a switch section fixed on the side of the piston driving means and a collar that moves in accordance with the direction of the piston, and detects a malfunction when the collar contacts the switch section.

Preferably, when the piston moves toward the distal end, the collar moves by a predetermined length,
When the piston moves to the rear end side, the piston moves along with the rear end, and is arranged so as not to contact the switch unit at a fixed interval when the movement of the piston is completed.

In this case, in the state of normal operation,
When the retraction movement of the piston in each injection operation is completed, the collar is located every time at a predetermined distance from the switch unit and does not come into contact with the switch unit. If a malfunction occurs, it is detected that the collar contacts the switch unit and the malfunction has occurred, and the signal processing unit can immediately stop the piston driving unit.

More preferably, the collar is fixed to a rod portion provided along a direction in which the piston moves, and the rod portion has a movement transmitting portion in which the movement of the piston is transmitted to the rod portion by frictional force. In the vicinity of the piston-side end of the rod-shaped portion, there is provided a movement preventing portion for preventing the piston from moving beyond a predetermined length in the direction in which the piston moves toward the distal end.

Preferably, the movement transmitting section has a moving body that moves together with the piston, and a contact section that receives a biasing force from the moving body and comes into contact with the rod-shaped section.

In this case, the collar fixed to the rod portion is
When the piston moves a predetermined length when moving forward toward the distal end, the piston is stopped by the movement preventing unit and does not move any further. Next, the collar is also retracted from the position with the backward movement of the piston, and when the backward movement is completed, the collar can be positioned every time at a predetermined distance from the switch unit. The predetermined length depends on the distance for moving the piston to the rear end side.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A medical injector head according to an embodiment of the present invention will be described. In the present medical injector head 100, a safety device for stopping the motor when a malfunction occurs is provided in addition to the conventional medical injector head.

Specifically, as shown in FIG. 1, a microswitch 115 and a collar 114 are provided as a sensor section 121 for detecting a malfunction. And
As shown in FIG. 10, in response to a signal from the sensor unit 121, a signal for stopping the motor
A malfunction detection control unit 10 as a signal processing unit for sending to C
0E is provided.

Although a syringe including a piston is not shown in FIG. 1, a syringe similar to the syringe shown in FIG. 13 and the like described in the section of the prior art is mounted. Other configurations are the same as those of the conventional medical injector head shown in FIGS. 1 and 11, and therefore, the same members are denoted by the same reference numerals and description thereof will be omitted.

Next, the sensor section 121 will be described more specifically. As shown in FIG.
5 is arranged on a frame to which the motor 110 is fixed. The collar 114 is fixed to a piano wire 113 disposed substantially parallel to the plunger 104. The piano wire 113 is provided so as to penetrate the position plate 112 guided by the guide rod 111. The diameter of the piano wire 113 is preferably about 2 mm, and it is desirable that the diameter is as light as possible.

The reason for making the piano wire as light as possible is that the injector head is usually used in a state where the syringe portion is tilted downward by about 45 ° to prevent air from entering, so that the piano wire is heavy. This is because they do not work quickly.

The piano wire 113 is positioned on the position plate 11
In the portion penetrating through 2, the predetermined movement transmitting portion 122 is provided so that when the plunger 104 moves, the piano wire 113 can also move along with the movement.

The movement transmitting section 122 will be described more specifically. As shown in FIG. 2 and FIG.
A cylinder 117 made of, for example, Teflon is mounted on 13. The cylinder 117 is fixed to the position plate 112. A concave portion 117a is provided in the cylinder 117, and the surface of the piano wire 113 is exposed. A contact portion 118 made of, for example, Teflon contacts the exposed surface of the piano wire 113 by receiving the elastic force of the spring 119.

Next, a malfunction detection mechanism for detecting a malfunction will be described with reference to a schematic diagram. Referring to FIG. 4, piano wire 11 provided with collar 114 and movement transmitting unit 122
Reference numeral 3 is arranged to pass between the motor-side frame 116a and the syringe-side frame 116b. The motor-side end 113a of the piano wire 113 is
The guide hole 120a of the frame 116b is inserted into the guide hole 120a of the frame 116b.
Has been accepted by each.

The piano wire 113 can move in the direction in which the piston moves due to the frictional force caused by the contact portion 118 contacting the piano wire 113. The guide hole 120b is provided with a detent 123, and the movement of the piano wire 113 toward the piston is particularly restricted.

By providing this detent 123,
In each injection operation, at the time when the movement of the piston to the rear end side is completed by a distance corresponding to an arbitrary increase amount of the contrast agent,
The collar 114 is always located at a predetermined distance S from the microswitch 115.
The predetermined interval S is, for example, 2 mm.

However, when the piston attempts to move to the rear end side beyond a predetermined distance due to a malfunction, the collar 114 comes into contact with the microswitch 115. In this way, the collar 114 is
A malfunction is detected by touching 15.

Next, the operation of the medical injector head will be described. First, FIG. 5 schematically shows an arrangement of the malfunction detection mechanism in a state corresponding to FIG. In this state, the collar 114 is located at a predetermined distance (for example, S = 2 mm) from the microswitch 115.

Further, the tip 113b of the piano wire 113
Distance W ₁ of the detent 123 of the guide hole 120b
Is, for example, 5 mm.

Next, in order to inject the contrast medium into the patient, FIG.
As shown in FIG. 4, the plunger 104 is moved a distance corresponding to the predetermined amount (Q) and the arbitrary increase amount (+ α), and the piston is advanced by L1. At this time, the piano wire 113 is moved by the movement transmitting section 122 of the position plate 112.
Also starts to move in accordance with the movement of the piston as indicated by arrow 131.

Then, as shown in FIG.
Where 3 is moved by a distance W _1, the distal end portion 113b
Corresponds to the detent 123. At this point, piano wire 11
3 can no longer move with the piston.

On the other hand, as described above, the movement transmitting section 122
The contact portion 118 is in contact with the piano wire 113 by receiving the elastic force of the spring 119. For this reason, even if the movement of the piano wire 113 is blocked, the position plate 112 does not stop and moves toward the arrow 132 as shown in FIG.
It stops when it has moved the distance L1.

Next, as shown in FIG. 15, for reducing the pressure in the syringe, optionally increment in the direction indicated the piston 10b in the arrow D ₂ (-α) amount corresponding to retract. At this time, the piano wire 113 moves together with the piston and stops in the direction of the arrow 133 as shown in FIG. The retreat distance of the piano wire 113 depends on an arbitrary increase amount of the contrast agent, but is preferably about 3 mm.

At the time when the backward movement of the piston 10b is completed, the collar 114 is located at a predetermined distance (for example, 2 mm) from the microswitch 115. That is, the collar 114 and the microswitch 115 return to the state shown in FIG. If the medical injector head is operating normally, the above operation is repeated, and a predetermined amount of the contrast agent is injected into the patient.

When such a series of injection operations is performed manually, the operator operates while checking the state of the medical injector head and the like. Therefore, when a malfunction occurs in the medical injector head, Is
The injection operation can be stopped immediately.

However, when the injection operation of the contrast agent is performed automatically, when the piston is moved backward, a malfunction occurs due to, for example, a program runaway, and the distance corresponding to the above-mentioned arbitrary increase amount (-α). It is conceivable that the piston moves backward beyond.

In such a case, in the medical injector head, as shown in FIG. 9, the piano wire 113 retreats in the direction of arrow 134 as the piston retreats. When the piano wire 113 retreats, the collar 114 fixed to the piano wire 113 comes into contact with the microswitch 115.

Then, as shown in FIG.
When 4 contacts micro switch 115, malfunction detecting section 100E recognizes that a malfunction has occurred, and sends a signal for stopping driving of motor 110 to main body control section 100C. Main unit control unit 1 that received the signal
In 00C, the output of the motor drive voltage S2 is immediately stopped by hardware control not receiving program control.

Thus, the backward movement of the piston 10B is stopped. As a result, the patient's blood is not sucked from the distal end portion of the syringe 10, and the patient is prevented from being adversely affected.

Further, in the next operation of injecting the contrast agent, the contrast agent is not injected into the patient together with the sucked blood. As a result, a predetermined amount of the contrast agent can be injected into the patient.

It should be noted that this medical injector head is not limited to the above-described series of injection operations, and may be operated in a case where the piston moves backward due to some malfunction from the standby state of the piston. It is possible to detect and stop the piston.

Further, in the above embodiment, the contrast agent is described as an example of the liquid to be injected into the patient. However, the present invention is not limited to the contrast agent but may be any other liquid. Similar effects can be obtained.

The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a medical injector head according to an embodiment of the present invention.

FIG. 2 shows the medical injector head II shown in FIG.
It is sectional drawing which shows the cross-sectional structure in -II.

FIG. 3 is an enlarged perspective view showing a structure of a portion of the position plate of the medical injector head shown in FIG. 1 through which a piano wire passes.

FIG. 4 is a schematic diagram showing a structure of a malfunction detecting mechanism for detecting a malfunction of the medical injector head shown in FIG. 1;

FIG. 5 is a schematic view showing an arrangement of a malfunction detection mechanism in a first injection step by the medical injector head shown in FIG. 1;

FIG. 6 is a schematic view showing an arrangement of a malfunction detecting mechanism in a second injection step by the medical injector head shown in FIG. 1;

FIG. 7 is a schematic view showing an arrangement of a malfunction detection mechanism in a third injection step by the medical injector head shown in FIG. 1;

FIG. 8 is a schematic view showing an arrangement of a malfunction detection mechanism in a fourth injection step by the medical injector head shown in FIG. 1;

FIG. 9 is a schematic diagram showing an arrangement of a malfunction detection mechanism when a malfunction occurs in the medical injector head shown in FIG. 1;

FIG. 10 is a block diagram of a part for controlling the operation of the medical injector head shown in FIG. 1;

FIG. 11 is a cross-sectional view of a conventional medical injector head.

FIG. 12 is a block diagram of a part for controlling the operation of a conventional medical injector head.

FIG. 13 is a schematic view showing a first injection step using a conventional medical injector head.

FIG. 14 is a schematic view showing a second injection step using a conventional medical injector head.

FIG. 15 is a schematic view showing a third injection step using a conventional medical injector head.

[Explanation of symbols]

100 medical injector head, 104 plunger, 106 ball screw, 108 potentiometer, 110 motor, 100B control panel, 100C body control unit, 100D reverse rotation control unit,
100E malfunction detector, 111 guide rod, 11
2 position plate, 113 piano wire, 113
a, 113b Tip, 114 Collar, 114a
Female screw, 114b Male screw, 115 Micro switch, 116a, 116b Frame, 117 cylinders, 11
7a recess, 118 contact part, 119 spring, 120
a, 120b opening, 121 sensor part, 122 movement transmitting part, 123 detent, 131-134 arrows.

Claims (5)

[Claims] 1. A cylindrical body having an extraction part on the front end side and an opening on the rear end side, and a movable body provided between the front end side and the rear end side of the body part. A medical injector head equipped with a syringe portion having a piston for forming a space for enclosing a liquid therein, and a piston driving means for giving the piston a distal or rearward movement. In a state in which the liquid is sealed inside the syringe portion,
A first piston control unit that outputs a signal for moving the piston to a distal end side by a predetermined distance to the piston driving unit in order to send out the liquid from the extraction unit; and a first piston control unit that controls the piston by a predetermined amount. A second piston control unit that outputs a signal for moving the piston to a rear end side by a predetermined distance to the piston driving unit in order to reduce a pressure of the liquid applied to the syringe unit after moving the distance, By the second piston control means, when moving the piston to the rear end side by a predetermined distance, if the piston attempts to move beyond the predetermined distance due to a malfunction, the malfunction is detected and the movement of the piston is detected. A safety means for outputting a signal for stopping the piston driving means to the piston driving means. 2. The safety device includes a sensor unit for detecting a malfunction, and a signal processing unit for outputting a signal for stopping the piston driving unit based on a signal sent from the sensor unit. The sensor unit has a switch unit fixed to the piston driving unit side and a collar that moves in accordance with the direction of the piston, and detects a malfunction by the collar contacting the switch unit. The medical injector head according to claim 1, wherein 3. The collar moves by a predetermined length when the piston moves toward the front end, and moves along with the piston when moving toward the rear end. When the movement of the piston toward the rear end of the distance is completed,
The medical injector head according to claim 2, wherein the medical injector head is arranged so as not to contact with the switch unit at a predetermined interval. 4. The collar is fixed to a rod-shaped portion provided along a direction in which the piston moves, and the rod-shaped portion has a movement transmitting portion in which the movement of the piston is transmitted to the rod-shaped portion by friction. In the vicinity of the piston-side end of the rod-shaped portion, a movement preventing portion is provided so that the rod-shaped portion does not move beyond the predetermined length in the direction in which the piston moves to the distal end side. 4. The medical injector head according to claim 3, wherein: 5. The medical injector according to claim 4, wherein the movement transmitting section has a moving body that moves together with the piston, and a contact section that receives an urging force from the moving body and comes into contact with the rod-shaped part. head.