JP3582216B2 - Monitoring equipment for medical equipment drives - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a monitoring device for a medical device driving device that drives a medical device such as an intra-aortic balloon pump (IABP) or an artificial heart (AH).
[0002]
[Prior art]
In medical devices such as IABP and AH, a medical device inserted into a patient is driven using gas as a driving fluid.
In such a medical device, it is necessary to prevent gas from entering the patient's blood by pinholes or the like generated in the medical device as much as possible, and to prevent gas occlusion of a patient's blood vessel. As means for that purpose, for example, as shown in Japanese Patent Application Laid-Open No. 60-106464, a primary piping system communicating with a pressure source and a secondary piping system for driving are connected to a pressure transmission partition device (generally, a capacity limiting device). (Referred to as a VLD or an isolator), and a driving device in which a secondary piping system in which a driving gas is sealed is closed. In such a driving device, since the driving secondary piping system is a closed system, even if gas leaks due to a pinhole or the like, compared to a case where a medical device is directly connected to a pressure source, the gas is leaked. The amount of leakage can be limited.
[0003]
[Problems to be solved by the invention]
However, when a balloon made of a thin polymer film is used as a driven device, such as IABP, gas escapes from the polymer film constituting the balloon by diffusion. Therefore, it is necessary to monitor the pressure of the driving secondary piping system (closed system) and, when the amount of gas decreases, to appropriately replenish the gas in the closed secondary piping system. This is because if the gas loss due to the diffusion is left as it is, the amount of gas for driving becomes too small, and the original functions such as IABP and AH may be lost.
[0004]
Therefore, the pressure in the secondary piping system, which is a closed system, is monitored.However, the pressure drops due to the natural escape to the outside of the system due to the diffusion, and the abnormalities such as pinholes in the medical equipment cause abnormalities outside the system. It is not always easy to determine that the pressure has decreased due to escaping.
[0005]
In addition, it is conceivable to provide a sensor in the drive fluid piping system to detect mixing of body fluid, but the detection is not easy.
The present invention has been made in view of such circumstances, and has been developed to prevent abnormalities such as pinholes occurring in medical devices.Early andAn object of the present invention is to provide a monitoring device for a medical device drive device that can accurately detect the drive device.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a monitoring device for a medical device drive device according to the present invention,
Driving gas composed of hose or tube for driving driven equipment by driving gasIn the middle of the piping system, a sensor that detects body fluid mixed in the piping system is mounted,
The piping system has an exhaust line branched from a main line to exhaust the driving gas under reduced pressure, and the sensor is mounted on the exhaust line..
[0007]
The sensor has a light emitting unit that irradiates light to the driving fluid flowing through the piping system, and a light receiving unit that receives light passing through the driving fluid from the light emitting unit. When the body fluid is not included, the detection by the light receiving unit is at a high level, and when the fluid flowing through the drive piping system includes the body fluid, the detection by the light receiving unit is at a low level, Preferably, the light emitting means and the light receiving means are set. In this case, a light emitting diode (LED) with or without a filter that emits blue or green light, a laser diode, or the like is preferably used as the light emitting means. As the light receiving means, a photo sensor diode, a CCD or the like is preferably used. It is preferable that the light emitting means and the light receiving means are arranged so as to face each other at a position of about 180 degrees in a direction substantially perpendicular to the longitudinal direction of the line of the drive piping system.
[0008]
The sensor has a light emitting unit that irradiates light to a fluid flowing through the piping system, and a light receiving unit that can receive light that is radiated from the light emitting unit to the driving fluid and diffusely reflected, and the driving pipe When the body fluid is not contained in the driving fluid flowing through the system, the detection by the light receiving means is at a low level, and when the body fluid is contained in the fluid flowing through the driving piping system, the detection by the light receiving means is at a high level. It is preferable that the light emitting means and the light receiving means are set so as to be at a level. In this case, as the light emitting means, a light emitting diode (LED) with or without a filter that emits red or yellow light, a laser diode, or the like is preferably used. As the light receiving means, a photo sensor diode, a CCD or the like is preferably used. It is preferable that the light emitting means and the light receiving means are arranged at positions substantially perpendicular to the longitudinal direction of the line of the drive piping system and at positions substantially at 90 degrees to each other.
[0009]
In the present invention, the sensor for detecting a body fluid such as blood is not limited to the optical sensor as described above, but may be a chemical sensor or the like capable of detecting a body fluid. However, an optical sensor is the simplest and cheapest and is preferred.
In the monitoring device of the medical device drive device according to the present invention, if a pinhole or other abnormality is formed in the medical device disposed in the patient's body, the pressure of the drive fluid is detected in order to detect the pinhole or other abnormalities. Instead of monitoring, it directly detects whether or not bodily fluids are mixed in the drive piping system of the drive fluid. This utilizes that when a pinhole or the like occurs in a medical device such as a balloon, a bodily fluid (for example, blood) corresponding to the gas leaked from the pinhole enters the drive piping system. In the present invention, since the body fluid such as blood that has entered the drive piping system is detected by the sensor, an abnormality such as a pinhole generated in the medical device can be detected at an early stage.
[0010]
It is difficult to determine the abnormal leakage of the driving fluid due to the pinhole and the escape (diffusion leakage) of the driving fluid due to diffusion through a membrane or the like constituting a medical device based on the gas pressure of the driving fluid. Abnormal leakage of fluid is easily mistaken for diffusion leakage. Unless misidentification is detected early, body fluids such as blood may enter the drive piping system from the pinhole and coagulate there. When a medical device is inserted into the body of a patient, coagulation of blood or the like in the drive piping system must be avoided as much as possible. In particular, it is necessary to avoid a situation in which blood or the like accumulates gradually inside the drive piping system over a long period of time.
[0011]
In the present invention, since the body fluid such as blood which has entered the drive piping system is directly detected by the sensor, an abnormality such as a pinhole generated in the medical device can be detected at an early stage, and the drive including the medical device can be detected. A situation such as blood coagulation occurring inside the piping system can be favorably prevented.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a monitoring device for a medical device drive device according to the present invention will be described in detail based on an embodiment shown in the drawings.
First embodiment
FIG. 1 is a schematic configuration diagram of a monitoring device of a medical device driving device according to an embodiment of the present invention, FIG. 2 is a circuit diagram of the monitoring device, and FIG. 3 is a schematic configuration diagram of a driving device using the monitoring device.
[0013]
The monitoring device 80 of the medical device drive device according to the embodiment shown in FIG. 1 is used, for example, incorporated in the drive device 9 for inflating and deflating the balloon 22 of the IABP balloon catheter 20 shown in FIG.
Prior to describing the monitoring device according to the present embodiment, the IABP balloon catheter 20 (FIGS. 3, 7, and 8) will be described first.
[0014]
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 thickness of about 100 to 150 μm. In the present embodiment, the balloon membrane in the expanded state has a cylindrical shape, but is not limited to this, and may have a polygonal cylindrical shape.
[0015]
The IABP balloon 22 is made of a material having excellent bending fatigue resistance. The outer diameter and length of the balloon 22 are determined according to the inner volume of the balloon 22, which greatly affects the assisting effect of the heart function, the inner diameter of the arterial blood vessel, and the like. The balloon 22 usually has an inner volume of 30 to 50 cc, an outer diameter of 14 to 16 mm when expanded, and a length of 210 to 270 mm.
[0016]
The distal end of the balloon 22 is attached to the outer periphery of the distal end of the inner tube 30 via a short tube 25 or directly by means such as heat fusion or adhesion.
The proximal end of balloon 22 is joined to the distal end of catheter tube 24 via a contrast marker, such as a metal tube 27, or directly. Through a first lumen formed inside the catheter tube 24, a driving gas body is introduced or led into the balloon 22, and the balloon 22 expands or contracts. The bonding between the balloon 22 and the catheter tube 24 is performed by heat fusion or adhesion with an adhesive such as an ultraviolet curable resin.
[0017]
The distal end of the inner tube 30 projects farther than the distal end of the catheter tube 24. The inner tube 30 is inserted through the inside of 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. Inside the inner tube 30, a second lumen that is not communicated with the inside of the balloon 22 and the first lumen formed in the catheter tube 24 is formed. The inner tube 30 sends the blood pressure taken in at the open end 23 at the distal end to the second port 32 of the branch portion 26, and measures the blood pressure fluctuation therefrom.
[0018]
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 inserting the balloon catheter into a body cavity such as a blood vessel, the balloon 22 is folded around the inner tube 30 and wound. The inner tube 30 shown in FIG. 7 is made of, for example, the same material as the catheter tube 24. The inner diameter of the inner tube 30 is not particularly limited as long as it is a diameter through which a guide wire can be inserted, and is, for example, 0.15 to 1.5 mm, and preferably 0.5 to 1 mm. The 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, and preferably about 700 to 1000 mm.
[0019]
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 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.
[0020]
Connected to the proximal end of the catheter tube 24 is a bifurcation 26 that is located outside the patient's body. The branch part 26 is formed separately from the catheter tube 24, and is fixed by means such as heat fusion or adhesion. The bifurcation 26 includes a first lumen 28 in the catheter tube 24 and a first port 28 for introducing or withdrawing a pressurized fluid into the balloon 22 and a second port 32 communicating with the second lumen of the inner lumen 30. Is formed.
[0021]
The first port 28 is connected to, for example, a driving device 9 shown in FIG. 8, and fluid pressure is introduced or led out into the balloon 22 by the driving device 9. The fluid to be introduced is not particularly limited, but helium gas or the like having a small mass is used so that the balloon 22 expands or contracts quickly according to the drive of the pump device 9.
[0022]
Details of the driving 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 fluctuation of the blood pressure in the artery taken from the open end 23 at the distal end of the balloon 22. Based on the fluctuation of the blood pressure measured by the blood pressure measuring device 29, the driving device 9 is controlled in accordance with the pulsation of the heart 1 shown in FIG. 8 to expand and contract the balloon 22 in a short cycle of 0.4 to 1 second. It has become.
[0023]
In the IABP balloon catheter 20, as described above, a helium gas or the like having a small mass is used as the fluid to be introduced and introduced into the balloon 22 in consideration of responsiveness and the like. Producing the positive pressure and the negative pressure of the helium gas directly by a pump or a compressor requires a large amount of gas consumption, which is difficult in terms of economy, and it is difficult to control the capacity. Has adopted. That is, the secondary piping system 18 communicating with the inside of the balloon 22 and the primary piping system 17 communicating with the pumps 4 a and 4 b as pressure generating means are separated by the pressure transmission partition device 40. The pressure transmission partition device 40 has a first chamber 46 and a second chamber 48 which are air-tightly partitioned by a diaphragm 52 and a plate 50, as shown in FIG. 4, for example. The plate 50 may not be necessarily provided, and the first chamber 46 and the second chamber may be partitioned only by the diaphragm 52.
[0024]
The first chamber 46 of the device 40 shown in FIG. 4 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. Further, the second chamber 48 communicates with the moisture removal line 71 through the port 72. The detailed description of the moisture removal line 71 will be described later.
[0025]
The fluid communication between the first chamber 46 and the second chamber 48 is cut off, but the pressure change (volume change) of the first chamber 46 is changed by the displacement of the diaphragm 52 (pressure change) of the second chamber 48 (volume). Change). By employing such a structure, the pressure fluctuation of the primary piping system 17 can be transmitted to the secondary piping system 18 without making the primary piping system 17 and the secondary piping system 18 communicate with each other. In addition, the volume (chemical equivalent) of the gas sealed in the secondary piping system 18 can be easily controlled to be constant. Furthermore, even if an abnormality occurs in the balloon 22 and gas leaks, it is possible to prevent the leak amount from becoming excessive.
[0026]
In the present 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 the balloon 22 to inflation / deflation by using a gas having a small mass.
[0027]
As shown in FIG. 3, in the primary piping system 17, two pumps 4a and 4b are arranged as 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. The first pressure tank 2 as a positive pressure tank is connected to a positive pressure output port of the first pump 4a via a pressure reducing valve 7. The second pressure tank 3 as a negative pressure tank is connected to the negative pressure output port of the second pump 4b via a check valve 8.
[0028]
The first pressure tank 2 and the second pressure tank 3 are provided with pressure sensors 5 and 6 as pressure detecting means for detecting the respective internal pressures. The pressure tanks 2 and 3 are connected to input terminals of a first solenoid valve 11 and a second solenoid valve 12, respectively. The opening and closing of these solenoid valves 11, 12 is controlled by control means (not shown), for example, in response to the pulsation of the patient's heart. The output terminals of the solenoid valves 11 and 12 are connected to an input port 42 (see FIG. 4) of a pressure transmission partition device 40 as a secondary pressure generating means.
[0029]
The output port 44 of the pressure transmission bulkhead device 40 shown in FIG. 4 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 closed system in which helium gas is sealed. This secondary piping system 18 is constituted by a hose or a tube. The secondary piping system 18 is provided with a pressure sensor 15 as pressure detecting means for detecting the internal pressure. The output of the pressure sensor 15 is input to the control means.
[0030]
The secondary piping system 18 is connected to an exhaust line 18b, which branches off from the main line 18a. The exhaust line 18b is connected via a solenoid valve 81 to a power-saving exhaust pump shown in the figure. The solenoid valve 81 and the exhaust pump provided in the exhaust line 18b are for evacuating the inside of the secondary piping system 18 to replace the interior of the secondary piping system 18 with helium gas before use. In a normal use state, the solenoid valve 81 is closed and the pump is not driven. Note that the exhaust pump may also serve as the second pump 4b. Further, in a system in which the inside of the secondary piping system 18 which is a driving piping system is periodically depressurized and evacuated, and the helium gas is regularly replenished, the exhaust pump may be operated even while the balloon 22 is in use.
[0031]
Further, 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 inside the secondary piping system 18. The replenishing device 60 has a primary helium gas tank 61. A secondary helium gas tank 64 is connected to the helium gas tank 61 via pressure reducing valves 62 and 63. A pressure sensor 65 is mounted on the secondary helium gas tank 64, detects the pressure in the tank 64, and controls the pressure in the tank 64 to be kept constant. For example, the pressure in the tank 64 is controlled to about 100 mmHg or less.
[0032]
A replenishing solenoid valve 66 is connected to the secondary helium tank 64 via a throttle valve 67, and an initial filling solenoid valve 68 is connected in parallel with the refilling solenoid valve 66. These solenoid valves 66 and 68 are controlled by control means. The initial charging electromagnetic valve 68 is opened in conjunction with the evacuation pump, and is used when initially filling the negative pressure secondary piping system 18 with helium gas. In a normal use state, the solenoid valve 68 does not operate.
[0033]
In the present embodiment, the inside of the secondary piping system 18 is set to a negative pressure, and when the helium gas is filled (replaced), the pressure in the system is monitored by the pressure sensor 15 and the helium gas is maintained until the pressure is determined by the capacity of the balloon 22. Is enclosed. For example, when a balloon catheter 20 having a capacity of 40 cc is used, the gas pressure at the time of filling the secondary piping system 18 is set to + 10 ± 4 mmHg (gauge pressure). The gas pressure at the time of filling the secondary piping system 18 is set to −30 ± 4 mmHg (gauge pressure).
[0034]
As shown in FIGS. 3 and 4, in the driving device of the present embodiment, the water removal line 71 is connected to the secondary piping system 18 as a driving piping system via the port 72 of the pressure transmission bulkhead device 40. is there. The moisture removal line 71 communicates with the main line 18 a of the secondary piping system 18 via the second chamber 48 of the partition device 40.
[0035]
As shown in FIG. 4, the moisture removing line 71 is configured to connect the second chamber 48 of the partition device 40 with the inside of the moisture condensing device 70 as the moisture removing means. The moisture condensing device 70 has a pipe connection portion 74 made of, for example, Duracon in order to obtain heat insulation. The cooling unit 76 is made of aluminum or stainless steel, and has an inner surface that is smooth so that water drops are easily dropped by gravity. In addition, a part of the outer surface of the cooling unit 76 is brought into close contact with a surface to be cooled by energization of a Peltier element capable of performing heat transfer by the Peltier effect. As the element, for example, a thermo module KSM-04017A manufactured by Komatsu Electronics is used. The opposite surface of the element is heated by heat transfer, so that cooling fins for heat radiation are closely attached. The periphery of the cooling unit 76 is covered with a heat insulating material 75 except for a part in contact with the Peltier element and the cooling fin. Thus, the inner surface of the coolant is kept at a low temperature 1 with a small amount of electric power. The cooling temperature is not particularly limited, but is preferably 5 ° C. or lower than room temperature. However, it is necessary to pay attention to freezing when the temperature is 0 ° C or less.
[0036]
The lower outlet where the condensed water flows down is provided with a pipe connection 78 made of a heat insulating material, just like the pipe connection 74 at the inlet. These connection portions can prevent the cooling unit 76 from being heated by conduction heat transfer from the connected pipes or the like. A discharge pipe 79 is connected below the pipe connection part 78.
[0037]
As shown in FIG. 3, the drainage pipe 79 is connected to the water reservoir 100. It is preferable that a water level sensor as shown in, for example, JP-A-3-63,068 is mounted on the water reservoir 100. The water level sensor detects the water level in the water reservoir 100. Only when the water level is sufficient, the electromagnetic valve 102 is opened to drain water to the outside. Further, it is preferable to open the electromagnetic valve 102 at a timing when a positive pressure is applied to the secondary piping system 18. This is because the positive pressure acts on the water surface of the water reservoir 100, and the water can be forcibly discharged to the outside. When the water level in the water reservoir 100 is sufficient, the drainage is performed at such a timing so that the driving gas (shuttle gas) such as helium gas sealed in the secondary piping system 18 is effectively leaked to the outside. Can be prevented.
[0038]
Such a water condensing device 70 is mounted on the secondary piping system 18 because the water vapor passes through the balloon 22 from the blood and mixes with the helium gas in the secondary piping system 18. This is for discharging from the inside of the next piping system 18 to the outside. In addition, the water removal line 71 may be configured to branch directly to the main line 18a of the secondary piping system 18, but it is better to separate the main line 18a from the main line 18a in this way, because the water removal efficiency is excellent. Water droplets can be prevented from splashing on the main line 18a where the driving gas reciprocates at high speed.
[0039]
Next, the monitoring device 80 of the present embodiment will be described in detail with reference to FIGS.
The monitoring device 80 is for detecting blood mixed in the secondary piping system 18 and has a light emitting diode 84 as a light emitting unit and a photo sensor diode 86 as a light receiving unit. These diodes 84 and 86 are held by the casing 82 so as to be substantially perpendicular to the longitudinal direction of the transparent tube constituting the secondary piping system 18 and centered on the transparent tube constituting the secondary piping system 18. , Are arranged at approximately 180 degrees symmetrical positions. The casing 82 is preferably made of a material that prevents light from entering from the surroundings.
[0040]
These diodes 84 and 86 may be arranged outside the tube constituting the piping system 18 or may be arranged inside the tube. The light emitting diode 84 emits blue or green light, and the light is received at a high level by the photo sensor diode 86 when a transparent fluid is flowing inside the tube. In the state where red fluid such as blood flows inside the tube, the light from the light emitting diode is low in light detection by the photo sensor diode 86.
[0041]
As shown in FIG. 2, the photo sensor diode 86 is connected in series with the resistor 87 between the ground and the constant voltage. Resistances 88 and 89 are connected in parallel with the diode 86 and the resistance 87. A connection point between the diode 86 and the resistor 87 is connected to the positive-phase input terminal of the comparator 92. Further, a connection point between the resistors 88 and 89 is connected to a negative-phase input terminal as a reference voltage. The output terminal of the comparator 92 is connected to a positive-phase input terminal via a high resistance 90 to provide hysteresis. The output terminal of the comparator is connected to a constant voltage via a resistor 91.
[0042]
When light is incident on the photosensor diode 86, the photosensor diode 86 is turned on, and the positive-phase input terminal of the comparator 92 is at a higher level than the negative-phase input terminal. Output goes high. When the light irradiated to the photosensor diode 86 becomes low level, the photosensor diode 86 is turned off, and the positive-phase input terminal of the comparator 92 becomes low level as compared with the negative-phase input terminal. The output of the output terminal 92 goes low.
[0043]
Therefore, if it is detected that the output of the output terminal becomes low level, the blue or green light from the light emitting diode 84 to the photo sensor diode 86 shown in FIG. It is possible to detect a state in which the like is mixed.
[0044]
In the present embodiment, the monitoring device 80 shown in FIG. 1 is connected to any position of the main line 18a of the secondary piping system 18 shown in FIG. (A part of the secondary piping system 18 including the water condensing device 70, the discharge pipe 79, and the water reservoir 100, and a part of the secondary piping system 18). It is attached. The monitoring device 80 may be installed at a plurality of positions. In particular, it is preferable to provide a monitoring device in the exhaust line 18b. This is because, in a system in which the inside of the secondary piping system 18 which is a driving piping system is periodically depressurized and evacuated, and the helium gas is regularly replenished, when a pinhole is generated in the balloon 22, the line 18b is connected to the line 18b. This is because blood is often involved. Further, if the monitoring device 80 is installed in the water reservoir 100, the blood gradually mixed into the secondary piping system 18 mixes with the water stored in the water reservoir 100, and the state is detected by the monitoring device 80. it can. In the above-described balloon catheter, the present monitoring device 80 may be provided at the catheter portion.
[0045]
Next, an operation example of the medical device drive device according to the present embodiment will be described.
In this embodiment, the pressure PT1 in the first pressure tank 2 is set to about 300 mmHg (gauge pressure) by driving the pump 4a shown in FIG. 3, and the second pressure tank 3 is driven by driving the pump 4b. Is set to about -150 mmHg (gauge pressure). Then, the pressure applied to the input end of the pressure transmission partition device 40 shown in FIG. 3 is switched to the pressure of the first pressure tank 2 and the second pressure tank 3 by alternately driving the solenoid valves 11 and 12. This switching timing is controlled by the control means so as to be performed in accordance with the heartbeat of the patient.
[0046]
FIG. 5A shows the pressure fluctuation detected by the pressure sensors 5 and 6. FIG. 5B shows the result of pressure change in the secondary piping system 18 shown in FIG. 3 detected by the pressure sensor 15 as a result of the pressure switching drive by the solenoid valves 11 and 12. The maximum value of the 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. 5B in the secondary piping system 18, a volume change occurs in the balloon 22 as shown in FIG. 5C, and the balloon 22 inflates and expands according to the heartbeat. Contraction becomes possible, and adjuvant treatment of the heart can be performed.
[0047]
In the present embodiment, the pressure detected by the pressure sensor 15 shown in FIG. 3 is changed at the timing * 2 shown in FIG. 6D (the timing at which the balloon is switched from the deflated state to the inflated state in FIGS. 6A and 6B). The solenoid valve 66 shown in FIG. 3 is opened so that the detected pressure P3 (FIG. 6A) becomes a predetermined value, and gas is replenished to the secondary piping system 18. The opening degree control of the electromagnetic valve 66 is not particularly limited, but is, for example, control of opening the valve 66 at a timing of 8 msec × n times. The n times are, for example, 2 to 10 times. In the present embodiment, the predetermined value of the detection pressure P3 is different depending on the volume of the balloon 22, and is, for example, + 10 ± 4 mmHg (gauge pressure) when the capacity is 40 cc, and − when the capacity is 30 cc. 30 ± 4 mmHg (gauge pressure). When the detected pressure P3 falls below these values, the control means drives the solenoid valve 66 to replenish helium gas into the secondary piping system 18 from the secondary helium gas tank 64, as shown in FIG. The detected pressure P3 is controlled so as to be a predetermined value.
[0048]
In the present embodiment, with the balloon 22 deflated, a gas of a fixed volume (constant mole number: chemical equivalent ratio) is introduced into the closed piping system 18 connected to the balloon 22. Thereafter, the reduction of the gas that decreases due to the permeation from the balloon 22 or the like is always monitored in a state where the balloon 22 is deflated.
[0049]
For this reason, in the present embodiment, the influence on the gas pressure of the balloon 22 that can be deformed by an external force is eliminated, and the chemical equivalent of the gas according to the volume of the arbitrary drive piping system 18 (including tubes and hoses) and the balloon is reduced. It is possible to keep it constant. With this control, the plateau pressure (pressure in a state where the balloon is inflated) P4 is also observed at the timing shown in FIG. 6 (C), and the balloon 22 is bent due to an unexpected situation such as bending. Can be detected. 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 usual, it can be determined that gas is leaking due to an unexpected situation other than permeation.
[0050]
Moreover, in the present embodiment, in addition to such pressure monitoring, the blood flowing into the secondary piping system 18 as the driving piping system is detected by the photosensor diode 86 using the monitoring device 80 shown in FIGS. Therefore, an abnormality such as a pinhole generated in the balloon 22 can be detected at an early stage. Therefore, it is possible to satisfactorily prevent blood coagulation from occurring inside the secondary piping system 18 including the balloon catheter 20.
[0051]
Second embodiment
The present embodiment is the same as the above embodiment except that the configuration of the monitoring device is the configuration shown in FIGS. 9 and 10, so that the description of the common parts is omitted and only the differences are described.
[0052]
As shown in FIG. 9, a monitoring device 80a according to the present embodiment is for detecting blood mixed in the secondary piping system 18, and includes a light emitting diode 84a as a light emitting unit and a photo sensor diode as a light receiving unit. 86a. These diodes 84a and 86a are held by the casing 82a so as to be substantially perpendicular to the longitudinal direction of the transparent tube constituting the secondary piping system 18, and centered on the transparent tube constituting the secondary piping system 18. , Approximately 90 degrees. The casing 82a is preferably made of a material that does not allow light to enter from the surroundings.
[0053]
These diodes 84a and 86a may be arranged outside the tube constituting the piping system 18, or may be arranged inside the tube. The light emitting diode 84a emits red or yellow light, and when a transparent fluid is flowing inside the tube, the light is hardly received by the photosensor diode 86a. When a red fluid such as blood flows inside the tube, the light from the light emitting diode 84a is irregularly reflected by the red fluid and also enters the photosensor diode 86a, and the light detection by the diode 86a is high. Level.
[0054]
As shown in FIG. 10, the photosensor diode 86a is connected in series with the resistor 87 between the ground and the constant voltage. Resistances 88 and 89 are connected in parallel with the diode 86a and the resistance 87. A connection point between the diode 86 a and the resistor 87 is connected to the negative-phase input terminal of the comparator 92. A connection point between the resistors 88 and 89 is connected to a positive-phase input terminal as a reference voltage. The output terminal of the comparator 92 is connected to a positive-phase input terminal via a high resistance 90 to provide hysteresis. The output terminal of the comparator is connected to a constant voltage via a resistor 91.
[0055]
In a state where the photosensor diode 86a is not irradiated with light (low level), the photosensor diode 86a is turned off, and the negative-phase input terminal of the comparator 92 is at a low level as compared with the positive-phase input terminal. Output terminal is at a high level. When the photosensor diode 86a is irradiated with light, the photosensor diode 86a is turned on, the negative-phase input terminal of the comparator 92 becomes higher in level than the positive-phase input terminal, and the output of the comparator 92 becomes higher. The output of the terminal goes low.
[0056]
Therefore, if it is detected that the output of the output terminal becomes low, the red or yellow light from the light emitting diode 86a shown in FIG. 10 is irregularly reflected by the red fluid inside the piping system 18, That is, it is possible to detect a state in which blood or the like is mixed in the piping system 18.
[0057]
The monitoring device 80a shown in FIG. 9 can be installed at the same position as in the first embodiment, and has the same operation and effect.
Third embodiment
In the first embodiment, an optical water level sensor is used as the water level sensor attached to the water reservoir 100 shown in FIG. 3, but the present invention is not limited to the optical sensor, and may be a capacitance type water sensor. A water level sensor or an ultrasonic water level sensor may be used. Rather, such a capacitance type water level sensor or an ultrasonic type water level sensor is preferable.
[0058]
FIG. 11 shows an example of a capacitance type water level sensor.
In the water level sensor shown in FIG. 11, semi-cylindrical electrode plates 104 and 106 are arranged on the outer periphery of the water reservoir 100 shown in FIG. 3, and an AC oscillator 105 is connected to one of the electrode plates 104. The other electrode plate 106 is connected to a positive-phase input terminal of an operational amplifier 108. The negative-phase input terminal of the operational amplifier is connected to the output terminal of the amplifier 108. An output terminal of the operational amplifier 108 is connected to a positive-phase input terminal of another operational amplifier 114 via a low-pass filter including a resistor 110 and a capacitor 112. A reference voltage setting means including a variable resistor 116 and a DC power supply 118 is connected to the negative-phase input terminal of the operational amplifier 114. By adjusting the resistance value of the variable resistor 116, the reference voltage (threshold voltage) changes, and the minimum voltage of the positive-phase input terminal at which the output terminal of the operational amplifier 114 becomes high level is determined.
[0059]
The output terminal of the operational amplifier 114 is connected to the base electrode of the transistor 120. When the output of the output terminal goes to a high level, the transistor 120 is turned on, and the drive coil of the solenoid valve 102 is driven. The valve 102 is opened to drain water. That is, when the water level (water in the water reservoir 100) existing between the electrodes 104 and 106 shown in FIG. 11 is high, the capacity between the electrodes 104 and 106 changes, the transistor 120 is turned on, and the electromagnetic valve 102 is turned on. Are driven to open the solenoid valve 102 shown in FIG. 3 to drain water. The water level at which the transistor 120 is turned on is adjusted by the variable resistor 116.
[0060]
According to the water level sensor of this embodiment, the water level of the water storage unit 100 shown in FIG. 3 can be accurately detected as compared with the optical water level sensor.
Note that the present invention is not limited to the above-described embodiments, and can be variously modified within the scope of the present invention.
[0061]
For example, in the above-described embodiment, as shown in FIG. 3, two pumps 4a and 4b are used as the pressure generating means. However, in the present invention, a single pump is used and a positive pressure output terminal is provided at its positive pressure output terminal. A first pressure tank 2 as a tank may be connected, and a second pressure tank 3 as a negative pressure tank may be connected to a negative pressure output terminal of the pump. In that case, the number of pumps can be reduced, which contributes to weight reduction and energy saving of the device.
[0062]
Further, in the above-described embodiment, the two solenoid valves of the third solenoid valve 11 and the fourth solenoid valve 12 shown in FIG. 3 are used as the pressure switching means. However, the present invention is not limited to this. The pressure applied to the input end of the pressure transmission partition 40 may be switched using the three-way valve.
[0063]
Further, the gas type of the primary piping system 17 is not limited to air, and may be another fluid. Further, the gas type of the secondary piping system 18 is not limited to helium gas, but may be another fluid.
Further, in the present invention, as shown in FIG. 12, a pressure generating means for directly reciprocating a predetermined volume of gas into the drive piping system 18 'may be used without using the primary piping system 17 and the pressure transmission bulkhead device 40. it can. The pressure means comprises, for example, a bellows 40a and a driving means (for example, a motor 40b) for driving the bellows 40a to expand and contract in the axial direction, and makes the inside or outside of the bellows 40a communicate directly 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 inflated and deflated. Other configurations are the same as those of the embodiment shown in FIG.
[0064]
In the first and second embodiments, the LED is used as the light emitting element and the photodiode is used as the light receiving element. However, various light receiving elements may be used. Examples include laser diodes, fluorescent tubes with filters, incandescent bulbs, phototransistors, Cds cells, solar cells, and the like.
[0065]
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 is driven by positive pressure and negative pressure. Can also be used. As another medical device, for example, an artificial heart can be exemplified.
[0066]
【The invention's effect】
As described above, according to the present invention, since the body fluid such as blood that has entered the drive piping system is directly detected by the sensor, it is possible to early detect an abnormality such as a pinhole occurring in a medical device. Can be. For this reason, it is possible to favorably prevent coagulation of blood or the like from occurring inside the drive piping system including the medical device.
Further, in the present invention, since the sensor is provided in the exhaust line, the body fluid such as blood which has entered the drive piping system can be detected early and accurately. This is because in a system in which the secondary piping system, which is the driving piping system, is periodically depressurized and evacuated, and helium gas is periodically replenished, when a pinhole is formed in the balloon, blood is supplied to this exhaust line. Is often involved.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a monitoring device for a medical device drive device according to an embodiment of the present invention.
FIG. 2 is a circuit diagram of a monitoring device.
FIG. 3 is a schematic configuration diagram of a driving device in which the monitoring device is used.
FIG. 4 is a sectional view of a main part showing an example of a pressure transmission partition device.
5 (A) is a graph showing a change in internal pressure of each pressure tank, FIG. 5 (B) is a graph showing a change in pressure on the balloon side, and FIG. 5 (C) is a graph showing a change in volume of the balloon. .
FIG. 6 is a chart showing the timing of pressure detection.
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 monitoring device according to another embodiment of the present invention.
FIG. 10 is a circuit diagram of a monitoring device.
FIG. 11 is a circuit diagram showing an example of a water level sensor.
FIG. 12 is a schematic configuration diagram of another drive device in which the monitoring device according to the embodiment of the present invention is installed.
[Explanation of symbols]
2 ... 1st pressure tank
3. Second pressure tank
4a, 4b ... Pump
5,6,15 ... Pressure sensor
11, 12, 16, 16, 19, 66, 68, 81 ... Solenoid valve
17 ... Primary piping system
18 Secondary piping system (driving piping system)
18 '... Drive piping system
20 ... Balloon catheter
22 ... Balloon
40 ... Pressure transmission partition
40a ... Bellows
60 ... Refilling device
70 ... Moisture condensing device (moisture removing device)
71 ... Water removal line
80, 80a ... Monitoring device
82, 82a ... Casing
84, 84a ... Light emitting diode
86, 86a ... Photosensor diode
100 ... pool
102 ... Solenoid valve

Claims (2)

During the driving gas driving the gas piping system composed of a hose or tube for driving a driven device, Ri tare sensor for detecting a body fluid mixed in the pipe system is mounted,
A monitoring device for a medical device drive device, wherein the piping system has an exhaust line branched from a main line to exhaust the drive gas under reduced pressure, and the sensor is attached to the exhaust line . The monitoring device for a medical device driving device according to claim 1, wherein the driven device is a balloon of a balloon catheter for an intra-aortic balloon pump.

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