JP3804092B2 - Medical expansion / contraction drive - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a medical inflation / deflation drive device that inflates / deflates a medical device such as an intra-aortic balloon pump (IABP) by alternately outputting positive pressure and negative pressure, for example.
[0002]
[Prior art]
For example, in an IABP balloon catheter, the balloon is inserted into an arterial blood vessel near the patient's heart, and inflated and deflated in accordance with the heart beat, thereby performing an adjuvant treatment of the heart. As a drive device for inflating and deflating a balloon, a drive device disclosed in Japanese Patent Application Laid-Open No. 60-106464 is known.
[0003]
The drive device shown in this publication has a primary piping system and a secondary piping system, and these systems are isolated by a pressure transmission partition device (generally called a capacity limiting device (VLD) or an isolator), The pressure fluctuation generated in the primary piping system is transmitted to the secondary piping system, and the balloon is inflated and contracted by the pressure change generated in the secondary piping system. In this way, the primary piping system and the secondary piping system are separated from each other by separating the fluid for driving the balloon and the fluid that is the source of the positive pressure and the negative pressure, and expanding and contracting the balloon. By maintaining the secondary piping system airtight except for leakage due to diffusion while improving responsiveness, pressure is generated at low cost without consuming a large amount of fluid gas in the relatively expensive secondary piping system. Because. In addition, by interposing a pressure transmission partition device between them, when the balloon is inflated and deflated in a state where the balloon membrane is damaged, the risk of gas exceeding a certain volume leaking from the balloon into the body is prevented. .
[0004]
By the way, in such an IABP balloon catheter, helium gas having a small mass and excellent responsiveness is preferably used as the gas sealed in the secondary piping system. However, since this helium gas has a low molecular weight, it diffuses through the balloon membrane and the walls of the tubes constituting the piping system even if pinholes are not formed in the secondary piping system. For example, even if helium gas is sealed in a sealed secondary piping system, the helium pressure may drop by several mmHg when the balloon is driven for 20 to 30 minutes.
[0005]
For this reason, it is necessary to appropriately replenish helium gas into the secondary piping system even during use of the balloon catheter. If this is neglected, the helium gas disappears from the secondary piping system, the balloon as the driven device does not expand sufficiently, and the cardiac function assisting effect is lost. For this reason, as a device for replenishing helium gas, the internal pressure of the secondary piping system is monitored by a pressure sensor, and when the detected pressure becomes a predetermined value or less, the electromagnetic pressure is set so that the detected pressure becomes a predetermined value or more. An apparatus is known in which a valve is opened a predetermined number of times in a short time, and helium gas is replenished from a high-pressure gas cylinder via a helium gas tank that is regulated for safety.
[0006]
However, such a helium gas replenishment device can supply gas indefinitely, because when a hole such as a pinhole is opened in a balloon, a large amount of gas is injected into the blood vessel of the patient, and the obstruction gas obstruction, and thus life There is a danger of causing a crisis. Therefore, in a conventional apparatus, a method is adopted in which helium gas is kept in a relatively low pressure state using a mechanical regulator or the like, and this is further divided into a plurality of times to supplement the secondary piping system. A mechanism is provided for monitoring and limiting the number of times the solenoid valve is opened and closed during a series of fillings and the time interval between the series of fillings and the start of the next series of fillings.
[0007]
[Problems to be solved by the invention]
However, in such a device according to the conventional example, the number of times of opening and closing by the electromagnetic valve can be grasped, but the filling capacity of helium gas per unit time cannot be grasped accurately. For example, the pressure inside the helium gas tank cannot be kept constant before and after opening and closing of the valve, and there is also variation in the opening and closing time of the solenoid valve, and the balloon pressure fluctuates due to the patient's blood pressure. To do. Therefore, the filling capacity of helium per opening and closing of the solenoid valve is not constant, and naturally the number of opening and closing of the solenoid valve when filling with helium is not constant. For this reason, it is not possible to accurately grasp the total filling capacity of helium gas from the number of opening and closing by the solenoid valve. Naturally, the time from the number of fillings or a series of fillings until the pressure in the secondary piping system drops and the next filling starts If the limit by monitoring at an interval or the like is set strictly, an uneasy warning or the like is generated due to the influence of the variation. Also, if the above monitoring restrictions are relaxed, gas leakage due to abnormalities such as pinholes formed in the secondary piping system or balloon catheter as a driven device (abnormal gas leakage), and leakage due to diffusion during normal operation It was difficult to distinguish (normal gas leakage).
[0008]
For example, as shown in FIG. 6B, even if the number of times of opening and closing of the solenoid valve for replenishing the helium gas is plotted on the vertical axis and the time axis is plotted on the horizontal axis, the number of times of opening and closing the valve is accurate. It is not reflected in. For this reason, it is difficult to clearly distinguish between abnormal gas leakage and normal gas leakage even if the time interval between the replenishment of helium gas is observed.
[0009]
The present invention has been made in view of such a situation, and provides a medical inflation / deflation drive device that can easily distinguish between normal and abnormal gas leaks in use. Objective.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the medical expansion / contraction drive device according to the present invention applies a positive pressure and a negative pressure to a piping system communicating with the driven device so as to repeat expansion and contraction of the driven device. The pressure generating means for applying alternately, the piping system pressure detecting means for detecting the internal pressure of the piping system, the gas supplementing means for supplementing the piping system with gas, and the amount of gas supplemented by the gas supplementing means. A medical expansion / contraction drive device having control means for controlling,
The gas replenishing means includes a primary gas tank in which the gas to be replenished to the piping system is sealed, a first valve means connected to the output side of the primary gas tank, and an openable / closable first valve means. A secondary gas tank communicated with the output side of the primary gas tank, tank pressure detecting means for detecting the pressure in the secondary gas tank, and connected to the output side of the secondary gas tank, the secondary gas tank connected to the inside of the piping system A second valve means for controlling replenishment of gas from the secondary gas tank by opening and closing the valve;
When the pressure detected by the piping system pressure detecting means at a timing when the control means switches the driven device from the contracted state to the expanded state becomes a predetermined value or less, the first valve means is closed, The second valve means is opened, the gas from the secondary gas tank to the piping system is replenished, and the pressure in the secondary gas tank detected by the tank pressure detecting means before and after the gas replenishment is detected. The operation is based on calculating the replenishment amount of the gas to the piping system.
[0011]
The piping system pressure detection means detects the pressure of the piping system at the timing of switching the driven device from the contracted state to the expanded state, and the control means determines whether or not the detected pressure is equal to or less than a predetermined value. It is preferable to do.
As the driven device, for example, an IABP balloon catheter can be preferably exemplified.
[0012]
In order to calculate the gas replenishment amount into the driven equipment side piping system using the medical expansion / contraction driving device according to the present invention, the following procedure is performed.
When the pressure detected by the piping system pressure detecting means becomes a predetermined value or less, the first valve means is closed and the second valve means is opened. Thereby, replenishment of the gas from a secondary gas tank to a piping system can be performed. Before and after the gas replenishment, the tank pressure detecting means detects the tank internal pressure. Meanwhile, since the secondary gas tank is shut off from the primary gas tank by the first valve means, the piping from the secondary tank is calculated from the pressure difference (P1-P2) before and after the gas replenishment and the volume V of the secondary gas tank. The replenishment amount of gas transferred to the system is required. The replenishment amount is proportional to (P1−P2) × V.
[0013]
The gas replenishment amount thus determined is recorded over time. The recording means preferably records on a semiconductor memory, a magnetic disk, an optical recording medium, or other recording medium, and can output to a screen or paper as necessary. Then, the time-dependent change of the recorded gas replenishment amount is observed, and when the gas replenishment interval is shortened and the calculated gas replenishment amount starts to increase, it is determined that an abnormal gas leak has occurred, and the process is advanced. An alarm can be issued. Whether or not the gas replenishment amount has started to increase can be automatically alerted if the central information processing unit (CPU) or the like appropriately reads and judges the change over time of the gas replenishment amount recorded in the recording means.
[0014]
In the present invention, it becomes possible to accurately grasp the amount of gas replenished to the driven equipment side piping system regardless of patient-side factors and mechanical variations, and pinholes generated in the driven equipment or piping system. It is possible to clearly distinguish between abnormal leakage due to the above and leakage at normal time, and an early warning can be given when abnormal.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a medical expansion / contraction drive device according to the present invention will be described in detail based on an embodiment shown in the drawings.
FIG. 1 is a schematic configuration diagram of a medical inflation / deflation drive device according to an embodiment of the present invention.
[0016]
The drive device according to the embodiment shown in FIG. 1 is used to inflate and deflate the balloon 22 of the IABP balloon catheter 20.
Prior to describing the medical inflation / deflation drive device according to the present embodiment, the IABP balloon catheter 20 will be described first.
[0017]
As shown in FIG. 7, the IABP balloon catheter 20 has a balloon 22 that expands and contracts in accordance with the heartbeat. The balloon 22 is formed of a cylindrical balloon film having a film thickness of about 100 to 150 μm. In the present embodiment, the shape of the balloon membrane in the expanded state is a cylindrical shape, but is not limited thereto, and may be a polygonal cylindrical shape.
[0018]
The IABP balloon 22 is made of a material excellent in bending fatigue resistance. The outer diameter and length of the balloon 22 are determined in accordance with the inner volume of the balloon 22 that greatly affects the assisting effect on the cardiac function, the inner diameter of the arterial blood vessel, and the like. The balloon 22 usually has an internal volume of 30 to 50 cc, an outer diameter of 14 to 16 mm when expanded, and a length of 210 to 270 mm.
[0019]
The distal end of the balloon 22 is attached to the outer periphery of the distal end of the inner tube 30 through a short tube 25 or directly by means such as heat fusion or adhesion.
The proximal end of the balloon 22 is joined to the distal end of the catheter tube 24 via a contrast marker such as a metal tube 27 or directly. Through the first lumen formed inside the catheter tube 24, pressure fluid is introduced or led into the balloon 22 so that the balloon 22 is expanded or contracted. The balloon 22 and the catheter tube 24 are joined by heat fusion or adhesion with an adhesive such as an ultraviolet curable resin.
[0020]
The distal end of the inner tube 30 projects farther from the distal end of the catheter tube 24. The inner tube 30 is inserted in the balloon 22 and the catheter tube 24 in the axial direction. The proximal end of the inner tube 30 communicates with the second port 32 of the branch portion 26. A second lumen that does not communicate with the first lumen formed inside the balloon 22 and the catheter tube 24 is formed inside the inner tube 30. The inner tube 30 is configured to send blood pressure taken at the opening end 23 at the distal end to the second port 32 of the branching portion 26 and measure blood pressure fluctuation therefrom.
[0021]
When the balloon catheter 20 is inserted into the artery, the second lumen of the inner tube 30 located in the balloon 22 is also used as a guide wire insertion lumen for conveniently inserting the balloon 22 into the artery. When the balloon catheter is inserted into a body cavity such as a blood vessel, the balloon 22 is wound around the outer periphery of the inner tube 30. The inner tube 30 shown in FIG. 5 is made of the same material as the catheter tube 24, for example. The inner diameter of the inner tube 30 is not particularly limited as long as the guide wire can be inserted, and is, for example, 0.15 to 1.5 mm, preferably 0.5 to 1 mm. The wall thickness of the inner tube 30 is preferably 0.1 to 0.4 mm. The total length of the inner tube 30 is determined according to the axial length of the balloon catheter 20 inserted into the blood vessel and is not particularly limited, but is, for example, about 500 to 1200 mm, preferably about 700 to 1000 mm.
[0022]
The catheter tube 24 is preferably made of a material having a certain degree of flexibility. The inner diameter of the catheter tube 24 is preferably 1.5 to 4.0 mm, and the wall thickness of the catheter tube 24 is preferably 0.05 to 0.4 mm. The length of the catheter tube 24 is preferably about 300 to 800 mm.
[0023]
Connected to the proximal end of the catheter tube 24 is a bifurcation 26 placed outside the patient's body. The branch portion 26 is formed separately from the catheter tube 24 and fixed by means such as heat fusion or adhesion. The bifurcation 26 includes a first port 28 for introducing or leading a pressure fluid into the first lumen in the catheter tube 24 and the balloon 22, and a second port 32 communicating with the second lumen of the inner tube 30. Is formed.
[0024]
The first port 28 is connected to, for example, a pump device 9 shown in FIG. 8, and fluid pressure is introduced into or led out from the balloon 22 by the pump device 9. The fluid to be introduced is not particularly limited, but helium gas having a small viscosity and mass is used so that the balloon 22 can be expanded or contracted quickly in response to the driving of the pump device 9.
[0025]
Details of the pump device 9 will be described later with reference to FIG.
The second port 32 is connected to the blood pressure fluctuation measuring device 29 shown in FIG. 8 and can measure the blood pressure fluctuation in the artery taken from the opening end 23 at the distal end of the balloon 22. Based on the blood pressure fluctuation measured by the blood pressure measuring device 29, the pump device 9 is controlled according to the pulsation of the heart 1 shown in FIG. 6, and the balloon 22 is expanded and contracted in a short cycle of 0.4 to 1 second. It is like that.
[0026]
In the IABP balloon catheter 20, as described above, helium gas having a small viscosity and mass is used as a fluid to be introduced into and led out from the balloon 22 in order to cause the balloon to expand and contract at a higher speed. Since it is not economical to create the positive and negative pressures of helium gas directly with a pump or a compressor, considering that helium gas is lost due to leakage from the seal portion, the structure shown in FIG. Adopted. That is, the secondary piping system 18 that communicates with the balloon 22 and the primary piping system 17 that communicates with the pumps 4a and 4b as primary pressure generating means are separated by the pressure transmission partition device 40. As shown in FIG. 2, for example, the pressure transmission partition device 40 includes a first chamber 46 and a second chamber 48 that are airtightly partitioned by a diaphragm 52 and a plate 50.
[0027]
The first chamber 46 communicates with the primary piping system 17 shown in FIG. The second chamber 48 communicates with the secondary piping system 18 through the port 44. Although the fluid communication between the first chamber 46 and the second chamber 48 is interrupted, the pressure change (volume change) in the first chamber 46 changes due to the displacement of the diaphragm 52. Change). By adopting such a structure, the pressure fluctuation of the primary piping system 17 can be transmitted to the secondary piping system 18 without causing the primary piping system 17 and the secondary piping system 18 to communicate with each other. Moreover, it is easy to control the volume (chemical equivalent) of the gas sealed in the secondary piping system 18 to be constant.
[0028]
In this embodiment, the internal fluid of the primary piping system 17 is air, and the internal fluid of the secondary piping system 18 is helium gas. The reason why the internal fluid of the secondary piping system 18 is helium gas is to increase the response of inflation / deflation of the balloon 22 by using a gas having low viscosity and mass.
[0029]
As shown in FIG. 1, the primary piping system 17 is provided with two pumps 4a and 4b as primary pressure generating means. One first pump 4a is a positive pressure generating pump (also referred to as a compressor; the same applies hereinafter), and the other second pump 4b is a negative pressure generating pump. A first pressure tank 2 as a positive pressure tank is connected to the positive pressure output port of the first pump 4 a via a pressure reducing valve 7. A second pressure tank 3 serving as a negative pressure tank is connected to the negative pressure output port of the second pump 4b via a throttle valve 8.
[0030]
The first pressure tank 2 and the second pressure tank 3 are equipped with pressure sensors 5 and 6 as pressure detecting means for detecting respective internal pressures. The pressure tanks 2 and 3 are connected to the input ends of the solenoid valve 11 and the solenoid valve 12, respectively. The opening and closing of the electromagnetic valves 11 and 12 is controlled by a control means (not shown), for example, corresponding to the heartbeat of the patient. The output ends of these solenoid valves 11 and 12 are connected to an input port 42 (see FIG. 2) of a pressure transmission partition device 40 as a secondary pressure generating means.
[0031]
The output port 44 of the pressure transmission partition device 40 shown in FIG. 2 is connected to the secondary piping system 18 shown in FIG. The secondary piping system 18 communicates with the inside of the balloon 22 and is a sealed system in which helium gas is sealed. The secondary piping system 18 is constituted by a hose or a tube. The secondary piping system 18 is equipped with a pressure sensor 15 as piping system pressure detecting means for detecting the internal pressure. The output of the pressure sensor 15 is input to the control means.
[0032]
Further, although not shown in the figure, an exhaust pump is connected to the secondary piping system 18 via a solenoid valve. The solenoid valve and the exhaust pump are for evacuating the inside of the piping system 18 in order to replace the inside of the secondary piping system 18 with helium gas before using the balloon catheter. The solenoid valve is closed and the exhaust pump is not driven.
[0033]
Further, the secondary piping system 18 is equipped with an electromagnetic valve 19, and when the gas pressure in the secondary piping system 18 rises above a predetermined value, the electromagnetic valve 19 opens for a predetermined time, It is configured to let gas escape. This control is performed by the control means 10.
Furthermore, a replenishing device 60 for replenishing a predetermined amount of helium gas is connected to the secondary piping system 18 so that the chemical equivalent of the gas is always kept constant in the secondary piping system 18. . The replenishing device 60 has a primary helium gas tank 61 as a primary gas tank. A first electromagnetic valve 63 as a first valve means is connected to the output side of the helium gas tank 61 via a pressure reducing valve 62. The opening and closing of the first electromagnetic valve 63 is controlled by the control means 10. A secondary helium gas tank as a secondary gas tank is connected to the output side of the first electromagnetic valve 63, and the secondary helium gas tank 64 communicates with the output side of the primary helium gas tank 61 by opening and closing the electromagnetic valve 63. It is supposed to be.
[0034]
The secondary helium gas tank 64 is equipped with a pressure sensor 65 as tank pressure detecting means, and detects the pressure in the tank 64 and is controlled so that the pressure in the tank 64 is kept substantially constant. For example, the pressure in the tank 64 is controlled to about 100 mmHg or less. The pressure detected by the pressure sensor 65 is input to the control means 10.
[0035]
The secondary helium tank 64 is connected to a second electromagnetic valve 68 as second valve means. The electromagnetic valve 68 is controlled by the control means 10. Although not shown, an initial charging solenoid valve is connected in parallel with the solenoid valve 68. The electromagnetic valve for initial filling is used when the helium gas is first filled in the secondary piping system 18 which is set to a negative pressure. In normal use, this solenoid valve does not operate.
[0036]
Next, an operation example of the medical inflation / deflation drive device according to the present embodiment will be described.
In the present embodiment, by driving the pump 4a, the pressure PT1 in the first pressure tank 2 is set to about 300 mmHg (gauge pressure), for example, and by driving the pump 4b, the pressure in the second pressure tank 3 is set. For example, PT2 is set to about -150 mmHg (gauge pressure). And the pressure added to the input end of the pressure transmission partition apparatus 40 shown in FIG. 1 is switched to the pressure of the 1st pressure tank 2 and the 2nd pressure tank 3 by driving the solenoid valves 11 and 12 alternately. The timing of this switching is controlled by the control means 10 so as to be performed in accordance with the heartbeat of the patient.
[0037]
FIG. 4A shows the pressure fluctuation detected by the pressure sensors 5 and 6. Further, FIG. 4B shows a result of detecting the pressure fluctuation in the secondary piping system 18 shown in FIG. 1 by the pressure sensor 15 as a result of the pressure switching drive by the electromagnetic valves 11 and 12. The maximum value of pressure fluctuation in the secondary piping system 18 is, for example, 289 mmHg (cage pressure), and the minimum value is −114 mmHg (gauge pressure). As a result of the pressure fluctuation shown in FIG. 4 (B) in the secondary piping system 18, the volume change shown in FIG. 4 (C) occurs in the balloon 22, and the balloon 22 is inflated and matched to the heartbeat. The contraction becomes possible, and an auxiliary treatment of the heart can be performed.
[0038]
Next, the operation of the control means shown in FIG. 1 will be described with reference to FIG.
First, in step S1, the pressure in the secondary piping system from the pressure sensor 15 shown in FIG. 1 is detected. At this time, in the present embodiment, the pressure sensor 15 shown in FIG. 1 at the timing * 2 shown in FIG. 5D (the timing at which the balloon is switched from the deflated state to the inflated state in FIGS. 5A and 5B). Is detected, and it is determined whether the detected pressure P3 (FIG. 5A) is equal to or less than a predetermined value Pm1. Otherwise, repeat step S1. The predetermined value Pm1 is, for example, 0 mmHg. The case where the detected pressure P3 (FIG. 5A) is equal to or less than the predetermined value Pm1 is a case where the amount of helium gas in the secondary piping system 18 is reduced. Proceed and refill with gas.
[0039]
In this embodiment, the pressure P3 when the balloon is deflated is used as a reference without using the plateau pressure P4 (pressure at the time of balloon inflation) detected at the timing of * 1 shown in FIG. 5C as the reference pressure. The pressure was used for the following reason.
When the balloon side pressure is detected at the timing indicated by * 1 in FIG. 5C and the gas in the balloon side piping is replenished so as to keep this pressure constant, , Without being aware of balloon volume fluctuations that occur due to inadvertent pressurization (applying wrong pressure, bending of the patient's blood vessels) or accidental trapping when inserted into a protrusion in the patient's blood vessel, There is a danger of filling the balloon side piping with helium gas as a driving gas in an insufficient amount and continuing to use it. Naturally, the expected life of such a deformed balloon is shorter than the original case, which is not preferable for the patient. Furthermore, if the internal pressure of the balloon exceeds the set upper limit due to an increase in blood pressure due to patient recovery, it is controlled so that helium gas is extracted from the balloon in the worst case, and the balloon may not be inflated.
[0040]
On the other hand, in this embodiment, as shown in FIG. 5 (D), in a state where the balloon 22 is deflated, the closed piping system 18 connected to the balloon 22 has a certain capacity (a certain number of moles: chemical equivalent ratio). Of gas. Thereafter, the reduction of the gas that is reduced due to permeation from the balloon 22 or the like is always monitored while the balloon 22 is deflated.
[0041]
For this reason, in this embodiment, the influence on the gas pressure of the portion of the balloon 22 that can be deformed by an external force is eliminated, and the chemical equivalent of the gas according to the capacity of the arbitrary drive piping system 18 (including tubes and hoses) and the balloon is determined. It becomes possible to keep it constant. By controlling in this way, the plateau pressure (pressure when the balloon is inflated) P4 is also observed to detect that the volume of the balloon 22 has changed due to an unexpected situation such as the balloon 22 being bent. be able to. For example, when the plateau pressure P4 becomes higher than usual, it can be determined that the balloon 22 is bent. Further, when the plateau pressure P4 becomes smaller than normal, it can be determined that the gas is leaking due to an unexpected situation other than permeation.
[0042]
In the present embodiment, when the patient blood pressure becomes higher than the plateau pressure P4, the volume of the balloon 22 is kept substantially constant, and the plateau pressure P4 changes at substantially the same value as the blood pressure.
Next, step S2 and subsequent steps shown in FIG. 3 will be described.
[0043]
If it is determined in step S1 that gas replenishment is necessary, in this embodiment, the first electromagnetic valve 63 shown in FIG. 1 is closed in step S2. As a result, communication between the primary helium gas tank 61 and the secondary helium gas tank 64 is blocked. Next, in step S3, the pressure P1 of the tank pressure sensor 65 shown in FIG. 1 is read. Next, in step S 4, the second electromagnetic valve 68 is opened n times for t milliseconds, and helium gas is replenished from the gas tank 64 into the secondary piping system 18. The t millisecond is not particularly limited, but is, for example, 8 milliseconds. Further, n times is not particularly limited, but is 1 to 10 times.
[0044]
Next, in step S5, the pressure sensor 15 reads the pressure P3 at the timing * 2 shown in FIG. 5D, and determines whether or not the pressure P3 has reached a predetermined value Pm2. This Pm2 is, for example, 10 mmHg. Step S4 is repeated until the pressure P3 becomes equal to or higher than the predetermined value Pm2, and the gas is continuously replenished.
[0045]
In step S5, when the detected pressure P3 becomes equal to or higher than the predetermined value Pm2, it can be determined that the gas supply is sufficient, and thus the gas supply is completed. Next, in step S6, the detected pressure by the pressure sensor 65 is detected. Read P2. The pressure P1 detected by the pressure sensor 65 is the pressure in the secondary helium tank 64 before gas replenishment, and the detected pressure P2 is the pressure in the secondary helium tank 64 after completion of gas replenishment. In addition, the communication from the primary helium gas tank 61 into the secondary helium gas tank 64 is blocked by the electromagnetic valve 63. Therefore, the replenishment amount of gas moved from the secondary helium tank 64 to the secondary piping system 18 is obtained from the pressure difference (P1−P2) and the volume V (measured in advance) of the secondary helium gas tank 64. The replenishment amount is proportional to (P1−P2) × V.
[0046]
Next, in step S8, the gas replenishment amount thus obtained is recorded over time. The recording means preferably records on a semiconductor memory, a magnetic disk, an optical recording medium, or other recording medium, and can output to a screen or paper as necessary. Then, the time-dependent change of the recorded gas replenishment amount is observed, and as shown in FIG. 6A, when the gas replenishment interval is shortened and the gas replenishment amount starts to increase, abnormal gas leakage occurs. It can be determined that it has occurred, and an alarm can be issued early. Whether or not the gas replenishment has started to increase can be automatically alerted if the central information processing device (CPU) or the like appropriately reads and determines the change over time of the gas replenishment amount recorded in the recording means.
[0047]
The present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention.
For example, in the above-described embodiment, the two pumps 4a and 4b are used as the primary pressure generating means. However, in the present invention, a single pump is used, and a first positive pressure tank is provided at the positive pressure output end thereof. The pressure tank 2 may be connected, and a second pressure tank 3 as a negative pressure tank may be connected to the negative pressure output end of the pump. In that case, the number of pumps can be reduced, which contributes to weight saving and energy saving of the apparatus. The pump is not limited to a diaphragm pump, and a linear piston pump, a rotary vane pump, a piston pump, a compressor, or the like may be used.
[0048]
Moreover, in the said embodiment, although two solenoid valves, the 3rd solenoid valve 11 and the 4th solenoid valve 12, were used as a pressure switching means, this invention is not limited to this, A single three-way switching valve May be used to switch the pressure applied to the input end of the pressure transmission partition wall 40.
[0049]
Furthermore, the gas type of the primary piping system 17 is not limited to air, and may be other fluids. Further, the gas type of the secondary piping system 18 is not limited to helium gas, and may be other fluid.
Furthermore, in the present invention, as shown in FIG. 9, pressure generating means for reciprocating a predetermined volume of gas directly into the secondary piping system 18 may be used without using the primary piping system 17 and the pressure transmission partition device 40. it can. The pressure means includes, for example, a bellows 40a and a driving means (for example, a motor 40b) that drives the bellows 40a to extend and contract in the axial direction, and the inside or the outside of the bellows 40a is directly communicated with the secondary piping system 18. By reciprocating the bellows 40a in the axial direction by a motor 40b or the like, gas is reciprocated directly into the secondary piping system 18 at a predetermined timing, and the balloon 22 is expanded and contracted. Other configurations are the same as those of the embodiment shown in FIG.
[0050]
In the above-described embodiment, the balloon catheter is used as the driven device. However, the driving device according to the present invention may be used for driving other medical devices as long as the medical device repeats expansion and contraction. it can.
[0051]
【The invention's effect】
As described above, according to the present invention, it is possible to accurately grasp the amount of gas replenished to the driven equipment side piping system, which is abnormal due to pinholes or the like generated in the driven equipment or the piping system. Leaks can be clearly distinguished from normal leaks, and warnings can be issued early in the event of an abnormality.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a medical inflation / deflation drive device according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of an essential part showing an example of a pressure transmission partition device.
FIG. 3 is a flowchart showing a control example of the medical inflation / deflation drive device according to the embodiment of the present invention.
4A is a graph showing changes in internal pressure of each pressure tank, FIG. 4B is a graph showing changes in pressure on the balloon side, and FIG. 4C is a graph showing changes in volume of the balloon. .
FIG. 5 is a chart showing pressure detection timing.
FIG. 6A is a graph showing a change over time in the amount of helium gas replenished, and FIG. 6B is a graph showing a change over time in the number of helium replenishments.
FIG. 7 is a schematic sectional view showing an example of a balloon catheter.
FIG. 8 is a schematic view showing an example of use of a balloon catheter.
FIG. 9 is a schematic configuration diagram of a medical inflation / deflation drive device according to another embodiment of the present invention.
[Explanation of symbols]
2 ... 1st pressure tank 3 ... 2nd pressure tank 4a, 4b ... Pump 5, 6 ... Pressure sensor 10 ... Control means 11, 12, 16, 19 ... Solenoid valve 15 ... Pressure sensor (piping system pressure detection means)
17 ... Primary piping system 18 ... Secondary piping system 20 ... Balloon catheter 22 ... Balloon 40 ... Pressure transmission partition wall 60 ... Replenishing device (gas replenishing means)
61 ... Primary helium gas tank (primary gas tank)
63 ... 1st solenoid valve (1st valve means)
64 ... Secondary helium gas tank (secondary gas tank)
65 ... Pressure sensor (tank pressure detection means)
68 ... Second solenoid valve (second valve means)

Claims (1)

Pressure generating means for alternately applying a positive pressure and a negative pressure to a piping system communicating with the driven device so as to repeat expansion and contraction of the driven device;
Piping system pressure detecting means for detecting the internal pressure of the piping system;
Gas replenishing means for replenishing the piping system with gas;
A medical expansion / contraction drive device having control means for controlling the amount of gas replenished by the gas replenishing means,
The gas replenishing means;
A primary gas tank filled with the gas to replenish the piping system;
A first valve means that can be opened and closed connected to the output side of the primary gas tank;
A secondary gas tank communicated with the output side of the primary gas tank by opening and closing the first valve means;
Tank pressure detecting means for detecting the pressure in the secondary gas tank;
A second valve means connected to the output side of the secondary gas tank and controlling replenishment of gas from the secondary gas tank into the piping system by opening and closing the valve;
When the pressure detected by the piping system pressure detection means at a timing when the control means switches the driven device from the contracted state to the expanded state becomes a predetermined value or less, the first valve means is closed, The second valve means is opened, gas is replenished from the secondary gas tank to the piping system, and the pressure fluctuation in the secondary gas tank detected by the tank pressure detecting means before and after the gas replenishment is detected. Based on the above, the medical expansion / contraction drive device operates to calculate the replenishment amount of the gas to the piping system.

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