JP2014200363A - Medicine solution administration device, and medicine solution administration method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medicine solution administration device controlling an amount of solution at high accuracy with a compact configuration.SOLUTION: A main body 2 of a medicine solution administration device 1 is structured as follows: a magnet 68 is placed on a diaphragm 64 of an injection pump 44; a detection part 69 composed of a Hall element 67 is mounted in the vicinity of the magnet; and a detection signal SD corresponding to a displacement width of the diaphragm 64 is generated in non-contact state by the Hall element 67. The main body 2 controls a voltage control signal CV to control the detection signal SD to feed back so as to come close to a target voltage, so that the displacement width of the diaphragm 64 is made close to a target distance to meet a unit discharge amount to a target discharge amount. Accordingly, the main body 2 controls a supply time of the voltage control signal CV to discharge the target discharge amount of the medicine solution as many times as desire and thereby the administration amount of the medicine solution can be adjusted at high accuracy.

Description

  The present invention relates to a drug solution administration device and a drug solution administration method, and is suitable for application when, for example, insulin is administered into the body.

  2. Description of the Related Art Conventionally, as a device that administers medicinal solution (insulin) to a patient, it is a portable device that is used by adhering to the patient's skin, the tip of a thin catheter is reached subcutaneously, and the medicinal solution is supplied by a pump through the catheter. Therefore, there has been proposed a drug solution administration device for administration into the body.

  As a pump mounted on such a drug solution administration device, it is desirable that the pump is small and lightweight and has low power consumption. Thus, as an example of a chemical solution administration device, a device equipped with a diaphragm pump that supplies a chemical solution by vibrating a diaphragm (vibrating plate) using a piezoelectric element has been proposed (for example, see Patent Document 1).

Japanese Patent Laid-Open No. 2003-299732 (FIG. 6)

  However, in general, a diaphragm pump using a piezoelectric element, even if a constant voltage is applied to the piezoelectric element, changes in pressure due to changes in fluid resistance, such as clogging on the subcutaneous side, and fluid resistance of the flow path on the chemical solution holding unit side. Due to the change, the distance (amplitude) from the position (top dead center) where the diaphragm is maximally displaced upward to the position (bottom dead center) where it is maximally displaced downward is not necessarily constant. There was a problem that the amount of the chemical supplied by the vibration (one stroke) was not constant.

  For this reason, the chemical liquid administration device equipped with the diaphragm pump has a problem that the discharge amount per stroke is not constant, and it is difficult to adjust the chemical liquid dosage to a desired value by controlling the number of times the diaphragm is driven. there were.

  In addition, there is a method of measuring and controlling the flow rate with a flow meter in a drug solution administration device. In the case of a drug, for example, insulin, a precise flow meter of 1 [μl] per hour is required, and a flow meter that can be used for this. There is a problem that a large size of the device is caused, and in particular, when it is used for carrying, a new problem such as an increase in size and weight of the device occurs.

  On the other hand, in order to make the amount of diaphragm displacement constant, the diaphragm drive is physically restricted to a range narrower than the drive displacement width generated by applying a sufficient drive voltage to the diaphragm. There is a device (for example, European Patent Application Publication No. 2469089) that makes the amount of displacement constant by using a displacement restricting portion sandwiched between restricting members such as a restricting plate.

  However, in such a configuration, the diaphragm is driven in a state in which the diaphragm is always in contact with the regulation plate, which causes a problem in the durability of the diaphragm. In particular, in the case of a diaphragm pump in which a piezoelectric element is directly bonded for miniaturization, an impact is directly applied to the piezoelectric element, causing problems such as cracking and durability due to the weakness of the piezoelectric element.

  In addition, when insulin is used as a drug solution, the diaphragm and the regulating member collide with each other and give a large stress to the drug solution, so that the aggregation of insulin is accelerated, the efficacy is deteriorated, and the catheter may be clogged by the aggregate. .

  The present invention has been made in view of the above points, and an object of the present invention is to propose a drug solution administration device and a drug solution administration method capable of controlling the liquid supply amount with high accuracy by a small configuration.

  In order to solve such a problem, the drug administration device of the present invention is a drug administration device that administers a drug solution into the user's body, and includes a pump unit that includes a pump for feeding the drug solution into the user's body; A reservoir for storing a chemical solution and a control unit for controlling the pump are provided, and the pump unit is used for a pump chamber for temporarily storing the chemical solution, and a suction channel for communicating between the pump chamber and the reservoir. A discharge channel communicating between the catheter and the pump chamber, the tip of which reached the body of the person, a one-way valve provided in each of the suction channel and the discharge channel, and a side of the pump chamber, A diaphragm for changing the volume of the pump chamber, a displacement means for displacing the diaphragm based on a set displacement amount, and a detection unit for detecting the displacement amount of the diaphragm are provided, and the control unit detects the displacement amount detected by the detection unit. When And to control the displacement means so as to eliminate the difference between the constant displacement.

  Further, in the chemical solution administration method of the present invention, it has a pump unit including a pump for feeding the chemical solution into the user's body, a reservoir for storing the chemical solution, and a control unit for controlling the pump, A pump chamber that temporarily stores a chemical solution, an inhalation flow path that communicates between the pump chamber and the reservoir, and a discharge flow that communicates between the catheter and the pump chamber whose tip reaches the body of the user Passage, one-way valve provided in each of the suction flow path and the discharge flow path, a diaphragm provided on the side of the pump chamber, and changing the volume of the pump chamber, and a displacement for displacing the diaphragm based on a set displacement amount And a detection step of detecting a displacement amount of the diaphragm by a predetermined detection unit, and a difference between the displacement amount and the set displacement amount by the predetermined control unit. As was to be provided and a control step of controlling the displacement means.

  As a result, the present invention does not use a precision flowmeter, and restricts the displacement of the diaphragm by the displacement restricting member and keeps it constant, thereby quantifying the displacement of the partition plate that discharges the chemical (upper). By making the distance from the dead center to the bottom dead center close to the specified target value, the amount of change in the volume of the storage space can be adjusted to a desired value, and the discharge amount per pump stroke can be made constant. The diaphragm can be driven without contacting other members, and there is no fear of the diaphragm being damaged, and a durable and small-sized metering pump can be realized.

  According to the present invention, the displacement width of the partition plate can be set to the target value without using a large precision flow meter, and by restricting the displacement of the diaphragm by the displacement restricting member and making it constant without quantification. In addition, since the amount of change in the volume of the storage space can be adjusted to the desired value, the durability is high, and when protein preparations such as insulin are used for the medicine, protein aggregation is small, resulting in the alteration of the medicine. Solution that is small in size, can prevent clogging due to aggregates, and is small and lightweight with a low patient burden when used on the skin surface. An administration device and a drug solution administration method can be realized.

It is a rough-line perspective view which shows the whole structure of a chemical | medical solution administration apparatus. It is a rough-line perspective view which shows the structure (1) of a main-body part. It is a basic diagram which shows the structure (2) of a main-body part. It is a rough-line perspective view which shows the structure of a bubble sensor. It is a rough-line circuit diagram which shows the structure of a bubble detection circuit. It is a rough-line perspective view which shows the structure (1) of a mounting part. It is a basic diagram which shows the structure (2) of a mounting part. It is a basic diagram which shows the flow path of the chemical | medical solution in a main-body part. It is a rough-line perspective view which shows the structure (1) of an infusion pump. It is a basic diagram which shows the structure (2) of an infusion pump. It is a basic diagram which shows the relationship between the back pressure and flow velocity in an infusion pump. It is a rough-line block diagram which shows the structure of an infusion pump control circuit. It is a flowchart which shows a chemical | medical solution administration processing procedure. It is a basic diagram which shows the structure of a puncture apparatus. It is an approximate line figure showing puncture operation (1). It is an approximate line figure showing puncture operation (2).

  Hereinafter, modes for carrying out the invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

[1. overall structure]
As shown in FIG. 1, the drug solution administration device 1 is roughly composed of a main body 2, a puncture device 3, and a controller (not shown).

  The puncture device 3 punctures the patient's skin with the puncture needle 97, thereby causing the distal end of the elongated tubular catheter tip 92 to reach subcutaneously. The puncture device 3 is used by being attached to the attachment portion 2N of the main body 2 only when a puncture needle is punctured into the patient's skin, and is removed from the main body 2 after the puncture (details will be described later).

  The controller stores the administration time and dose for basal administration set in advance by the doctor based on the prescription in a memory (such as a flash memory described later) in the main body 2. The controller also stores a dose per carbohydrate amount prescribed and taken by a doctor for bolus administration and a bolus dose calculated from the amount of carbohydrate input by the patient at the time of administration in a memory in the main body 2. Remember.

  The main body 2 stores a medical solution such as insulin therein, and injects a medicinal solution having a memorized dose subcutaneously through the catheter chip 92. Moreover, the main-body part 2 is comprised small and lightweight, and it is assumed that it is continuously used for about 2 to 3 days, for example, in the state affixed on the patient's skin with the adhesive tape 2S.

[2. Main unit]
As shown in FIG. 1, the main body 2 is formed in a flat rectangular parallelepiped shape as a whole. As a result, the main body 2 has a small amount of protrusion from the skin surface, reduces sleep disturbance at bedtime, and reduces interference with the door handle when worn on the abdomen. Is not conspicuous in appearance.

  Further, as shown in an exploded perspective view in FIG. 2, the main body 2 is entirely covered with an upper housing 11 and a lower housing 12 that respectively constitute approximately half of a rectangular parallelepiped. Furthermore, the main body 2 achieves a waterproof function by screwing both of the upper casing 11 and the lower casing 12 with an elastomer sealing material (so-called packing, not shown) sandwiched therebetween. .

  The lower housing 12 constitutes the lower unit 2B by incorporating various components therein. The upper unit 2A is stacked on the upper side of the lower unit 2B so as to be accommodated in the upper housing 11.

  The upper casing 11 is formed into a thin hollow rectangular parallelepiped shape, and the upper surface, the front surface, the rear surface, the left surface, and the right surface are closed, the lower surface is open, and there are through holes in the vertical direction. doing.

  In the vicinity of the front end of the upper surface of the upper casing 11, a hole portion 11H made of a round hole penetrating vertically is formed, and further, an upper cylindrical shape made of a hollow cylinder so as to communicate with the hole portion 11H. The part 11C is erected downward. The upper cylindrical portion 11C constitutes a part of the mounting portion 2N, and a spiral thread groove 11S is formed on the inner peripheral surface thereof.

  Further, on the lower side of the upper surface plate in the upper housing 11, cylindrical screw receiving projections (bosses) 11P elongated in the vertical direction are provided at four positions.

[2-1. Configuration of upper unit]
The upper unit 2 </ b> A is configured around a plate-like substrate 13. The substrate 13 is formed in a thin plate shape in the vertical direction and is a so-called wiring substrate, and a wiring pattern is formed on the surface or inside thereof. The board 13 is provided with mounting holes 13H at four locations corresponding to the screw receiving projections 11P of the upper housing 11.

  On the surface of the substrate 13, as shown in FIG. 3A, an electronic component 15 made of a semiconductor element such as a CPU, a communication-like LSI, a resistor, a capacitor, etc. is attached, and a plurality of batteries for supplying power 16 and an antenna (not shown) for communication with the controller are also attached.

  Incidentally, the electronic component 15 includes a CPU (Central Process Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a flash memory, and the like. The CPU, ROM, RAM, flash memory, and the like function as a control unit 20 that controls the entire body 2 (details will be described later).

  A bubble sensor 21 is attached to the upper surface of the substrate 13. The bubble sensor 21 is formed in an elongated cylindrical shape in the front-rear direction, connected to the lower unit 2B side by a pipe 22 connected to the front end, and connected to the bubble removal filter 24 by a pipe 23 attached to the rear end. ing.

  As shown in FIG. 4, the bubble sensor 21 is configured around a cylindrical tube 21A. The tube 21A is made of a non-conductive material, and is configured to be strong enough not to be easily deformed, so that a chemical solution flows inside.

  Around the tube 21A, two electrodes 21B and 21C are arranged so as to face each other. The electrodes 21B and 21C are both made of a flat metal material, but are curved along the outer periphery of the tube 21A. Further, around the electrodes 21B and 21C, a tube 21A and a shield 21D for protecting the electrodes 21B and 21C are attached.

  Since the electrodes 21B and 21C are opposed to each other with the tube 21A interposed therebetween, they can be regarded as capacitors. Hereinafter, this is referred to as a capacitor 31. The capacitance of the capacitor 31 is determined by the relative dielectric constant of the nonconductor present between the electrodes 21B and 21C, that is, the relative dielectric constant of the substance present in the tube 21A and the tube 21A, in addition to the distance and area of the electrodes 21B and 21C.

  In general, the relative dielectric constant of air is about 1, and the relative dielectric constant of chemicals such as water and insulin is about 80. For this reason, the capacity | capacitance of the capacitor | condenser 31 changes greatly according to whether the bubble which is contained in the chemical | medical solution which flows into the tube 21A is contained.

  Therefore, the main body 2 detects whether or not bubbles are included in the chemical liquid flowing in the tube 21 </ b> A of the bubble sensor 21 based on the capacitance of the capacitor 31 by the bubble detection circuit 30 shown in FIG. 5. . Incidentally, the bubble detection circuit 30 is incorporated on the substrate 13 (FIG. 2).

  In the bubble detection circuit 30, a capacitor 31 and a resistor 32 having a predetermined resistance value are connected in parallel, one end of which is grounded, and the other end is connected to a common terminal of the switch 33. The switch 33 has two terminals t1 and t2 in addition to the common terminal, and switches the connection destination of the common terminal to the terminal t1 or the terminal t2 based on the control of the control unit 20.

  A terminal t 1 of the switch 33 is connected to the reference voltage source 34. The reference voltage source 34 generates a predetermined reference voltage E1.

  On the other hand, the terminal t2 of the switch 33 is connected to the inverting input terminal of the operational amplifier 35 used as a comparator. A DC power source 36 that generates a predetermined reference voltage E2 with respect to the ground potential is connected to the non-inverting input terminal of the operational amplifier 35. The reference voltage E2 is a voltage lower than the reference voltage E1. The operational amplifier 35 supplies an output signal output from the output terminal to the control unit 20.

  With this configuration, the bubble detection circuit 30 charges the capacitor 31 by first switching the switch 33 to the terminal t1 side. At this time, the potential difference between the electrodes 21B and 21C in the capacitor 31 is the reference voltage E1 or the vicinity thereof.

  Next, the bubble detection circuit 30 switches the switch 33 to the terminal t2 side. In the operational amplifier 35, immediately after the switch 33 is switched to the terminal t2, the reference voltage E2 is applied to the non-inverting input terminal, while the inverting input terminal has a larger reference voltage E1 or a voltage value close thereto. Since it is applied, a negative output signal is output to the control unit 20. At this time, the control unit 20 starts timing by the built-in timer from the time when the output signal is switched to negative.

  Thereafter, the capacitor 31 is gradually discharged as a current flows through the resistor 32, and accordingly, the potential difference between the electrodes 21B and 21C is gradually reduced. When the potential difference between the electrodes 21B and 21C eventually becomes equal to or less than the reference voltage E2, the operational amplifier 35 outputs a positive output signal to the control unit 20. At this time, the control unit 20 recognizes the time from when the output signal switches to negative until it returns to positive (hereinafter referred to as the discharge time TED).

  Here, when the capacity of the capacitor 31 is relatively large, that is, when there are almost no bubbles in the chemical solution in the tube 21A (FIG. 4) of the bubble sensor 21, the discharge time TED is a relatively long time. On the other hand, when the capacity of the capacitor 31 is relatively small, that is, when many bubbles are included in the chemical solution in the tube 21A, the discharge time TED is a relatively short time.

  Therefore, the control unit 20 compares the discharge time TED with a predetermined threshold value to determine whether or not the capacity of the capacitor 31 is large, that is, whether or not there are many bubbles in the chemical solution in the tube 21A.

  As described above, the bubble sensor 21 utilizes the fact that the capacitance of the capacitor 31 changes according to the bubbles contained in the chemical solution, detects the capacitance by the bubble detection circuit 30, and determines whether or not there are many bubbles by the control unit 20. It is made to determine. Incidentally, when it is determined that the chemical solution in the tube 21A contains many bubbles, the control unit 20 executes a bubble removal process described later.

  The bubble removal filter 24 is formed in a long and narrow cylindrical shape in the front-rear direction, connected to the bubble sensor 21 by a pipe 23 connected to the rear end, and connected to the lower unit 2B side by a pipe 25 connected to the front end. Yes.

  The bubble removal filter 24 includes a large number of porous hollow fibers having an outer diameter of about 300 [μm], for example. Further, on the outlet side (the piping 22 side) of the bubble removal filter 24, a narrow tube or a throttle (not shown) that generates a specified fluid resistance with respect to a specified flow rate is installed. Pressure is applied to the chemical solution inside the hollow fiber to expel bubbles from the hollow fiber to the outside. When a chemical solution containing bubbles is supplied via the pipe 23, the bubble removal filter 24 allows the chemical solution to pass through the hollow fiber and then flows out from the pipe 25.

  At this time, the hole of the hollow fiber allows the gas in the chemical solution to escape to the outside of the hollow fiber, while retaining the liquid in the hollow fiber without passing the liquid. As a result, the bubble removal filter 24 can remove bubbles while leaving the liquid contained in the chemical solution.

[2-2. Configuration of lower unit]
The lower unit 2 </ b> B (FIGS. 2 and 3B) is configured around the lower housing 12. The lower housing 12 is formed in the shape of a hollow rectangular parallelepiped thin like the upper housing 11 and is generally vertically symmetrical with the upper housing 11, that is, the front, rear, left, right and bottom surfaces are substantially symmetrical. It is blocked and the top surface is open.

  However, the lower housing 12 is provided with a screw mounting hole through which the upper and lower casings are screwed, a catheter puncture port on the lower surface, a hole for injecting a drug solution into the drug holding portion (reservoir 41), and the like. For example, the lower housing 12 is provided with attachment holes 12H at four locations corresponding to the screw receiving protrusions 11P of the upper housing 11, respectively.

  A reservoir 41 is attached near the center rear of the lower housing 12. The reservoir 41 is formed in a flat cylindrical shape that is thin in the vertical direction, and occupies about half the volume in the lower housing 12. The reservoir 41 is made of a flexible material and is formed in a hollow shape so that a chemical solution can be stored therein.

  An injection part 42 is disposed on the left rear side of the reservoir 41. The injection portion 42 has an injection port opened on the lower surface side, and normally closes the injection port with a rubber stopper (not shown). This inlet is connected to the reservoir 41 via a pipe 43.

  When the reservoir 41 is filled with a chemical solution, the injection unit 42 inserts a syringe injection needle (not shown) filled with the chemical solution from the drug bottle into the rubber stopper and is injected from the syringe through the injection needle. Is supplied to the reservoir 41 via the pipe 43. In addition, even after the injection needle 42 is pulled out after the supply of the chemical solution from the syringe, the injection portion 42 can be prevented from leaking the chemical solution because the insertion port of the injection needle is naturally closed by the rubber plug elasticity.

  In the left front of the reservoir 41, an infusion pump 44 for flowing the chemical solution is disposed. The infusion pump 44 has a suction port 44A for sucking a chemical liquid connected to the reservoir 41 via a pipe 45, and a discharge port 44B for discharging the chemical liquid connected to a flow sensor 47 via a pipe 46.

  Based on the control of the control unit 20, the infusion pump 44 sucks the chemical solution in the reservoir 41 through the suction port 44 </ b> A and the pipe 45 and discharges the chemical solution from the discharge port 44 </ b> B to the flow sensor 47 through the pipe 46. (Details will be described later).

  The flow sensor 47 is configured in a columnar shape, and causes the chemical liquid flowing in from the pipe 46 connected to one end to flow out from the pipe 48 connected to the other end, and the chemical liquid flows when the injection pump 44 moves. Or not, and notifies the control unit 20 of the detection result.

  By the way, the flow sensor 47 indicates whether or not the chemical solution is flowing in synchronism with the timing of driving the pump by checking whether the catheter or piping is clogged or whether there is an uncontrolled flow (free flow). Is detected by

  As the flow sensor 47, for example, as a system using a thermistor alone as a heating source and a temperature sensor, for example, a sensor that heats the thermistor with a constant current and detects a temperature change of the thermistor due to a continuous flow of a chemical solution is applicable. The flow sensor 47 uses a heating source and a temperature sensor separately. For example, the thermistor, resistor, heater wire, or semiconductor is used as the heating source, and the thermistor, platinum resistor, semiconductor, or the like is used as the temperature sensor. A combination of these can be used as appropriate.

  The pipe 48 is connected to the middle cylindrical portion 49. As shown in the perspective view of FIG. 6 and the cross-sectional view of FIG. 7, the middle cylindrical portion 49 is a member formed in a hollow cylindrical shape, and is provided at a position near the front of the lower housing 12. It is attached to the lower cylindrical part 12C. Both the middle cylindrical portion 49 and the lower cylindrical portion 12C constitute a part of the mounting portion 2N.

  The lower cylindrical portion 12C has a shape such that a short cylindrical outer peripheral portion 12CB is connected vertically along the outer periphery of the bottom portion 12CA formed in a disc shape. The bottom portion 12CA is formed in a conical shape whose upper surface is downward, the center is located below the periphery, and a hole portion 12CH penetrating vertically is formed in the center.

  The inner cylindrical surface 49 has a smooth inner peripheral surface 49S. Further, the outer peripheral portion at the lower end of the middle cylindrical portion 49 is scraped off to form a fitting portion 49A (FIG. 6), and the middle cylindrical portion 49 is bonded in a state where the fitting portion 49A is fitted with the outer peripheral portion 12CB of the lower cylindrical portion 12C. Thus, the lower cylindrical portion 12C is integrated.

  Further, in the middle of the middle cylindrical portion 49, a hole portion 49H penetrating inside and outside is formed. The hole 49H is inserted so that the pipe 48 (FIG. 3) is in close contact with each other, so that the inside of the pipe 48 communicates with the internal space of the middle tubular portion 49.

  Further, the vicinity of the upper end of the middle cylindrical portion 49 is formed thick so as to protrude outward, and a circumferential groove portion 49D is formed on the upper surface thereof. A packing 50 made of an annular member having flexibility is fitted into the groove 49D. When the upper casing 11 is fixed to the lower casing 12, the packing 50 is sandwiched between the middle cylindrical portion 49 and the upper cylindrical portion 11 </ b> C, thereby bringing the two into close contact with each other. .

  With this configuration, the middle cylindrical portion 49 is bonded to the lower cylindrical portion 12C by the fitting portion 49A, and the upper casing 11 is fixed to the lower casing 12 and combined with the upper cylindrical portion 11C. As a result, the mounting portion 2N is formed.

  On the other hand, a bubble removal pump 51 that causes the chemical liquid to flow is disposed in front of the reservoir 41. The bubble removal pump 51 has a suction port 51A for sucking a chemical solution connected to the reservoir 41 via a pipe 52, and a discharge port 51B for discharging the chemical solution connected to a pipe 53. The pipe 53 is connected to the pipe 22 of the upper unit 2A.

  The pipe 52 is connected to the distribution connector 41D in the reservoir 41. The distribution connector 41D is fixed to the central portion of the lower sheet in the reservoir 41, and is a four-distribution type connector that connects the pipe 52 and the four pipes 41P to each other. The four pipes 41P are respectively arranged in the reservoir 41 from the vicinity of the center toward the front-rear direction and the left-right direction, and an opening is fixed to the end portion of the lower sheet in the reservoir 41.

  In general, when there are bubbles in the reservoir 41, the bubbles are collected on the upper side in the reservoir 41 because the specific gravity is smaller than that of the chemical solution. On the other hand, the main body 2 may be directed in various directions because the patient may change postures in various directions after being attached to the skin of the patient in any direction.

  In this respect, the pipe 52 can suck the air bubbles in the reservoir 41 through the pipe 41P connected to the distribution connector 41D regardless of which direction the main body 2 faces.

  The bubble removing pump 51 sucks the chemical solution in the reservoir 41 through the suction port 51A and the pipe 52 based on the control of the control unit 20, and sequentially connects the upper unit 2A from the discharge port 51B through the pipe 53 and the pipe 22. The liquid chemical is discharged to the bubble sensor 21 (details will be described later).

  A pipe 54 is connected to the reservoir 41. The pipe 54 extends forward to the right of the reservoir 41 and has a tip directed upward, and the tip is connected to the pipe 25 of the upper unit 2A. For this reason, the chemical solution flowing out from the bubble removal filter 24 of the upper unit 2A is supplied into the reservoir 41 through the pipe 25 and the pipe 54 in order.

[2-3. Chemical route]
Here, if the path | route of the chemical | medical solution in the main-body part 2 is arranged, it can represent like the schematic diagram of FIG. As can be seen from FIG. 8, the main body 2 is formed with two systems of paths, an injection path F1 and a bubble removal path F2.

  The injection path F1 is a one-way path from the reservoir 41 to the pipe 45, the injection pump 44, the pipe 46, the flow sensor 47, the pipe 48, and the mounting portion 2N. That is, in the injection path F1, the chemical solution sucked from the reservoir 41 by the injection pump 44 is made to flow to the mounting portion 2N via the flow sensor 47.

  Actually, in the main body 2, when the chemical solution administration process for administering the chemical solution in the reservoir 41 to the patient is performed, the chemical solution is operated along the injection path F <b> 1 by operating the injection pump 44 based on the control of the control unit 20. Is fed to reach the mounting portion 2N.

  On the other hand, the bubble removal path F2 starts from the reservoir 41 and returns to the reservoir 41 again through the pipe 52, the bubble removal pump 51, the pipes 53 and 22, the bubble sensor 21, the pipe 23, the bubble removal filter 24, and the pipes 25 and 54. It has become an annular path.

  That is, in the bubble removal path F2, the chemical liquid sucked from the reservoir 41 by the bubble removal pump 51 is passed through the bubble removal filter 24 via the bubble sensor 21, and then returned to the reservoir 41 again.

  In practice, the main body 2 periodically performs an air bubble detection operation for detecting whether or not air bubbles are contained in the chemical solution in the reservoir 41, for example, once every hour. If so, the bubble removing operation for removing the bubbles is further executed.

  Specifically, the control unit 20 causes the chemical solution to flow along the bubble removal path F2 by operating the bubble removal pump 51 for a certain period of time as the bubble detection operation. This fixed time is a time that is defined in advance as a time for the bubble in the reservoir 41 to reach the bubble sensor 21.

  At this time, the control unit 20 determines whether or not bubbles exist in the chemical based on whether or not the detection value by the bubble detection circuit 30 (FIG. 5) including the bubble sensor 21 is greater than a predetermined threshold value. To do.

  Here, when the detected value is larger than the predetermined threshold value, the control unit 20 causes the bubble removal pump 51 to continue to operate as the bubble removal operation to cause the chemical liquid to flow along the bubble removal path F2, thereby removing the bubble removal filter. 24, bubbles in the chemical solution are removed.

  At this time, the control unit 20 monitors the bubbles in the chemical solution detected by the bubble sensor 21 and stops the bubble removal operation when the detection value by the bubble detection circuit 30 falls below a predetermined threshold.

  As described above, the main body 2 causes the chemical liquid to flow along the injection path F1, thereby causing the chemical liquid to reach the mounting portion 2N, and also causes the chemical liquid to flow along the bubble removal path F2, thereby causing the chemical liquid in the chemical liquid to flow. While detecting a bubble, it is made to remove this bubble.

[2-4. Configuration and control of pump]
Next, the configuration and control of the injection pump 44 and the bubble removal pump 51 will be described. Since the bubble removal pump 51 is configured in substantially the same manner as the infusion pump 44, the infusion pump 44 will be described below as an example.

[2-4-1. Infusion pump configuration]
As shown in FIG. 9, the infusion pump 44 as a pump part is formed in a rectangular parallelepiped shape as a whole, and is configured around a base 61 that occupies the lower side. The base portion 61 is formed in a flat rectangular parallelepiped shape that is vertically thin, and a suction port 44 </ b> A and a discharge port 44 </ b> B each having a thin cylindrical shape are provided projecting rearward on the rear surface.

  As shown in a schematic cross-sectional view in FIG. 10, the upper surface of the base 61 is formed with a slit-shaped recess. In addition, a channel for allowing the chemical liquid to flow from the suction port 44A to the discharge port 44B is formed inside the base 61.

  A valve 62 as a one-way valve is provided between a flow path 61A and a flow path 61B as a suction flow path communicating from the suction port 44A. The valve 62 is a so-called check valve, and functions as an intake valve that allows the chemical liquid to flow in the direction from the flow path 61 </ b> A toward the flow path 61 </ b> B but not in the opposite direction.

  The channel 61B communicates with a storage space 61C as a pump chamber. The storage space 61C is formed between a depression formed on the upper surface of the base 61 and a diaphragm 64 that covers the upper side of the depression so as to be sealed. The depression formed on the upper surface of the base 61 is formed so that the volume of the storage space 61C becomes substantially zero when the diaphragm 64 is bent to the maximum in the downward direction.

  Further, a flow path 61D as a discharge flow path is communicated with the storage space 61C. The flow path 61D communicates with a flow path 61E as a discharge flow path with a valve 63 as a one-way valve interposed therebetween. The valve 63 is a so-called check valve similar to the valve 62, and functions as a discharge valve that allows the chemical liquid to flow in the direction from the flow path 61D to the flow path 61E but not in the opposite direction. ing. The flow path 61E communicates with the discharge port 44B.

  The diaphragm 64 has a plate shape that is thin in the vertical direction and slightly smaller than the base 61, and is fixed so as to be in close contact with the upper surface of the base 61. The diaphragm 64 is made of a flexible material such as a silicon plate or a stainless steel plate, and the center portion can be displaced vertically with respect to the base portion 61.

  Incidentally, the depression formed on the upper surface of the base 61 has a shape that minimizes the volume of the storage space 61C without coming into contact with the diaphragm 64 when the diaphragm 64 is displaced so as to protrude downward. .

  The piezoelectric element 65 as the displacement means is formed in a plate shape that is thin in the vertical direction and slightly smaller than the diaphragm 64, and its lower surface is in close contact with the upper surface of the diaphragm 64. The piezoelectric element 65 is a laminated piezoelectric element or a bimorph piezoelectric element, and is displaced in the vertical direction integrally with the diaphragm 64 when a voltage based on the control of the control unit 20 is applied.

  With this configuration, when a predetermined voltage (for example, a positive voltage) is applied to the piezoelectric element 65 based on the control of the control unit 20, the infusion pump 44 displaces the central portion of the piezoelectric element 65 and the diaphragm 64 upward. The volume of the storage space 61C is expanded.

  At this time, the injection pump 44 causes the chemical liquid to flow in from the flow path 61B by the action of the valves 62 and 63, but does not flow in the chemical liquid from the flow path 61D. That is, the infusion pump 44 sucks the chemical solution from the suction port 44A. The amount of the chemical solution sucked here corresponds to an enlarged portion in the volume of the storage space 61C, and is an amount corresponding to the displacement width of the piezoelectric element 65 and the diaphragm 64. Incidentally, the displacement width of the piezoelectric element 65 and the diaphragm 64 is about 10 [μm] at the maximum.

  Next, when a different voltage (for example, a negative voltage) is applied to the piezoelectric element 65 based on the control of the control unit 20, the infusion pump 44 displaces the central portion of the piezoelectric element 65 and the diaphragm 64 downward. The volume of the storage space 61C is reduced.

  At this time, the injection pump 44 causes the chemical liquid to flow out from the flow path 61D by the action of the valves 62 and 63, but does not flow out from the flow path 61B. That is, the infusion pump 44 discharges the chemical solution from the discharge port 44B. The amount of the chemical liquid discharged here corresponds to a reduction in the volume of the storage space 61C, and is an amount corresponding to the displacement width of the piezoelectric element 65 and the diaphragm 64.

  Thus, the infusion pump 44 drives the diaphragm 64 by periodically changing the voltage applied to the piezoelectric element 65 based on the control of the control unit 20, and sucks and discharges the liquid medicine from the suction port 44A. The chemical solution is alternately discharged from the pump so as to function as a so-called diaphragm type metering pump.

  FIG. 11 is a diagram showing the relationship between the back pressure and the flow rate change when the drive frequency of the pump to be used is varied. As shown in FIG. 11, the infusion pump 44 has a flow rate (that is, a flow rate) per unit time in accordance with a pressure (hereinafter referred to as a back pressure) applied to the diaphragm 64 due to the magnitude of the fluid resistance of the subcutaneous infusion portion. ) Will change.

  The flow rate of the infusion pump 44 is reduced by about 30% when a back pressure of 40 [kPa] is applied, compared to a case where no back pressure is applied. When used for an insulin pump, the required maximum flow rate is about 20 [μl / min].

  For this reason, the displacement width of the diaphragm 64 is set to 10 [μm] when the vibration frequency is 50 [Hz] and no back pressure is applied, and 7 [μm] when the back pressure of 40 [kPa] is applied. Varies.

  In addition to this configuration, as shown in FIGS. 9 and 10, four columnar portions 61 </ b> P are erected on the top surface of the base portion 61 in the vicinity of the front, rear, left, and right vertices. The columnar portion 61P is made of a highly rigid material, for example, a ceramic substrate or a resin containing glass fiber.

  A plate-like substrate 66 having a projection area substantially equal to that of the base 61 is attached to the upper end of the columnar part 61P. That is, the substrate 66 is supported at the four corners from below by the columnar portion 61P.

  The substrate 66 is formed in a plate shape that is relatively thin in the vertical direction, and is made of a strong material having a large rigidity and a small deflection, such as a ceramic plate. For this reason, unlike the diaphragm 64 and the piezoelectric element 65, the substrate 66 is hardly displaced with respect to the base portion 61.

  A Hall element 67 is attached to the lower surface side of the center of the substrate 66. On the other hand, a magnet 68 is attached to a substantially upper surface side of the piezoelectric element 65. Hereinafter, the Hall element 67 and the magnet 68 are collectively referred to as a detection unit 69.

  The Hall element 67 changes the resistance value according to the change of the surrounding magnetic field due to the so-called Hall effect. Therefore, in this embodiment, a constant resistance is connected in series with the Hall element 67, a constant voltage or a constant current is applied, and the voltage at this time is amplified and supplied to the control unit 20 as the detection signal SD. This detection signal SD changes the voltage according to the distance between the Hall element 67 and the magnet 68, that is, according to the position of the diaphragm 64 relative to the base 61.

  Based on the detection signal SD supplied from the hall element 67, the control unit 20 recognizes the distance between the hall element 67 and the magnet 68, that is, the displacement of the diaphragm 64 with respect to the base 61 (details will be described later). To do).

  For example, when the voltage of the detection signal SD is 1 [Vp-p] (hereinafter referred to as a target voltage), the infusion pump 44 is 3 [μm] on the side on which the diaphragm 64 protrudes downward and protrudes upward. The dimensions of each part are set so as to displace 3 [μm] toward the side. Thus, the infusion pump 44 has a total displacement width of the diaphragm 64 of 6 [μm] (hereinafter referred to as a target distance). At this time, the discharge amount by one vibration is 0.025 [μl] (hereinafter referred to as this). Called a target discharge amount).

  Here, in the infusion pump 44, when the back pressure is applied, the displacement amount when the chemical solution is discharged from the discharge port 44B, that is, the displacement amount when the diaphragm 64 is convex downward is smaller than the designed displacement amount. There is a possibility. For this reason, in the infusion pump 44, the amount of vertical displacement in the diaphragm 64 is made uniform by adjusting the rectangular wave applied to the piezoelectric element 65 in consideration of the back pressure.

  For example, it is assumed that the positive and negative peak values in the detected SD signal become +0.3 [V] and −0.5 [V], respectively, with the back pressure applied to the infusion pump 44. At this time, the diaphragm 64 is displaced by 1.8 [μm] on the downward convex side and 3 [μm] on the upward convex side.

  Here, a positive drive voltage is applied to the piezoelectric element 65 when the diaphragm 64 is distorted to the downward convex side. In this infusion pump 44, for example, a positive and negative asymmetric rectangular wave with positive and negative peak voltages of + (10 + α) [V] (where α is a positive real number) and −10 [V] with respect to the piezoelectric element 65, respectively. By applying this voltage, the amount of displacement in the upper and lower sides of the diaphragm 64 can be made equal.

  As described above, the infusion pump 44 is provided with a detection unit 69 that detects the displacement width of the diaphragm 64 by the Hall element 67 and the magnet 68 in addition to the same configuration as the general diaphragm pump.

[2-4-2. Control of infusion pump]
Next, the control of the infusion pump 44 by the control unit 20 will be described. An infusion pump control circuit 70 shown in FIG.

  As described above, the control unit 20 includes a CPU, a ROM, a RAM (all not shown), and the like, and refers to a time signal supplied from a real-time clock (RTC) 71 with reference to a medicinal solution administration program (in detail, (To be described later).

  The oscillator (OSC) 72 generates a source signal S <b> 1 having a rectangular wave of 50 [Hz], for example, based on the control of the control unit 20, and supplies this to the switch 73. The switch 73 is configured to switch “ON” or “OFF” based on the control signal CS from the control unit 20 and supplies the source signal S1 to the programmable booster circuit 74 when “ON”.

  The control unit 20 outputs a voltage control signal CV that is a digital value for setting a voltage to be applied to the piezoelectric element 65 of the infusion pump 44, and converts this to an analog value by a digital / analog (D / A) converter 75. And supplied to the programmable booster circuit 74.

  The programmable booster circuit 74 generates the drive signal S2 for the piezoelectric element 65 by boosting the amplitude of the source signal S1 to the voltage represented by the voltage control signal CV, and supplies this to the piezoelectric element 65 of the injection pump 44. Here, for example, the drive signal S2 is a rectangular wave including positive and negative asymmetry having a voltage of about 0 to 20 [Vp-p] and a period of 50 [Hz].

  When the drive signal S2 is supplied, the piezoelectric element 65 drives the diaphragm 64 every 20 [ms] which is the cycle of the drive signal S2. At this time, the piezoelectric element 65 moves the magnet 68 fixed integrally therewith in the vertical direction with the same amount of displacement as that of the diaphragm 64.

  The control unit 20 controls the constant voltage source 76 to supply a predetermined voltage from the constant voltage source 76 to the constant resistance circuit connected in series with the Hall element 67 only when the infusion pump 44 is in operation. Incidentally, the control unit 20 cuts off the voltage supply from the constant voltage source 76 except when the injection pump 44 is in operation, and suppresses the power consumption of the entire main body unit 2.

  The Hall element 67 generates a detection signal SD that changes according to the position of the magnet 68 by the voltage supplied from the constant voltage source 76, converts the detection signal SD into a digital value by the analog / digital converter 77, and controls the controller 20. To supply.

  The detection signal SD obtained here is an output in which the displacement width of the diaphragm 64 is a voltage change (ie, amplitude), and the amplitude changes according to the displacement width.

  The control unit 20 compares the voltage change of the detection signal SD that is a detection value of the displacement width of the diaphragm 64 with 1 [Vp−p] that is the target voltage. Thereby, the control unit 20 can recognize whether the discharge amount of one stroke of the diaphragm 64 is larger, smaller, or equivalent to the target discharge amount of 0.025 [μl].

  Further, the control unit 20 controls the voltage of the programmable booster circuit 74 to reduce the difference between the voltage of the detection signal SD and the target voltage (1 [Vp-p]), and the voltage of the detection signal SD is set to the target voltage. The actual discharge amount by one stroke of the next diaphragm 64 can be brought close to the target discharge amount of 0.025 [μl].

  Specifically, for example, the control unit 20 may reduce the value of the voltage control signal CV when the voltage of the detection signal SD is larger than the target voltage, and the voltage control signal when the voltage of the detection signal SD is smaller than the target voltage. What is necessary is just to increase the value of CV.

  Therefore, the control unit 20 controls the voltage supplied to the programmable booster circuit 74 so as to reduce the difference between the voltage of the detection signal SD and the target voltage based on the comparison result between the acquired detection signal SD and the target value in the chemical solution administration process. Control to adjust the signal CV.

  There is a physical upper limit for the voltage applied to the piezoelectric element 65. Therefore, the control unit 20 needs to keep the control range within the dynamic range in which the piezoelectric element 65 can be displaced. Further, the relationship between the applied voltage and the displacement in the infusion pump 44 is deteriorated in linearity as the displacement increases due to the characteristics of the diaphragm 64. Therefore, it is desirable to use the piezoelectric element 65 in a range where the displacement is 1/10 or less of the dynamic range.

  The back pressure on the horizontal axis in FIG. 11 mainly corresponds to an increase in pressure due to fluid resistance such as clogging on the catheter side punctured under the skin of a living body. In the infusion pump 44, assuming that the normal use is possible if the back pressure can be controlled to be 40 [kPa] or less, when the drive frequency is 50 [Hz], the applied voltage is 200 [Vp-p] at the maximum. The maximum flow rate is 230 [μl / min].

  In the case of insulin administration, the maximum flow rate may be 20 [μl / min], and this value is 1/10 or less of the above-mentioned 230 [μl / min].

  When the flow rate is set to 20 [μl / min] or less in insulin administration, the infusion pump 44 can reduce the displacement of the piezoelectric element 65 to 1/10 or less of the dynamic range, and the linearity between the applied voltage and the displacement can be reduced. It can be secured. That is, the infusion pump 44 can be controlled and used as long as the applied voltage is within a range of approximately 0 to 20 [Vp-p], which is 1/10 or less of the dynamic range.

[2-5. Chemical solution treatment]
Next, details of the chemical solution administration process by the main body 2 will be described. The main body 2 is provided with two types of operation modes such as a bolus mode and a basal mode.

  The basal mode is an operation mode in which a specified amount of drug solution is steadily administered, for example, 1 [μl] per hour. However, in this basal mode, the main body 2 does not always administer a very small amount of drug solution, but intensively administers 1 [μl] drug solution, for example, once per hour for about 0.8 seconds, An intermittent operation is performed such as resting for the remaining 59 minutes and 59.2 seconds.

  On the other hand, the bolus mode is an operation mode that is set, for example, before the patient ingests a meal, and temporarily administers a specified amount of drug solution such as 10 [μl].

  Specifically, the main body 2 executes the chemical solution administration process in the basal mode or the bolus mode according to the flowchart of FIG.

  Incidentally, the main body 2 is in a state in which the puncturing operation described later is completed, that is, the hub 91 is attached to the attachment portion 2N, and the distal end of the catheter tip 92 has reached the patient's skin, and priming to the distal end of the catheter sleeve is completed It is assumed that the drug solution in the reservoir 41 can be administered subcutaneously to the patient.

  When the start of medication is instructed via a controller (not shown), the control unit 20 of the main body 2 starts the chemical solution administration processing procedure RT1 and proceeds to step SP1. In step SP1, the control unit 20 acquires a time measurement signal representing the current time from the real-time clock 71 (FIG. 12), and proceeds to the next step SP2.

  In step SP2, the control unit 20 determines whether or not the current time is a predetermined operation end time. If a negative result is obtained here, this indicates that the chemical solution administration process can be continued. At this time, the control unit 20 proceeds to the next step SP3.

  Incidentally, as the operation end time, for example, a time after 3 days (72 hours later), which is a permissible limit time for the change of the medicine over time, is set in advance after a predetermined operation start operation is performed via an operation unit (not shown). Yes.

  In step SP3, the control unit 20 is requested to operate in the bolus mode by receiving an instruction from a controller (not shown) or by operating a bolus switch (not shown) provided in the operation unit. Determine whether or not. If a negative result is obtained here, this indicates that the operation should be performed in the basal mode. At this time, the control unit 20 proceeds to the next step SP4.

  In step SP4, the control unit 20 reads from the flash memory the operation start time in the basal mode, that is, the time to administer the drug solution once per hour, and proceeds to the next step SP5.

  In step SP5, the control unit 20 determines whether or not the current time is the operation start time. If a negative result is obtained here, this means that the drug solution should not be administered at this time. At this time, the control unit 20 returns to step SP1 again and repeats a series of processes.

  On the other hand, if an affirmative result is obtained in step SP5, this indicates that the current time is the operation start time in the basal mode, and the drug solution should be administered. At this time, the control unit 20 proceeds to the next step SP6.

  Further, when a positive result is obtained in step SP3, this indicates that the drug solution should be administered in the bolus mode in accordance with the operation instruction of the patient or the like. At this time, the control unit 20 proceeds to the next step SP6.

  In step SP6, the control unit 20 reads the dose stored in the flash memory in advance in the basal mode, and reads out the dose stored in the flash memory in advance in the bolus mode, or the controller ( The set dose AD of the drug solution is acquired based on the content received from (not shown), and the process proceeds to the next step SP7.

  In step SP7, the control unit 20 sets the operation time T according to the following equation (1) based on the acquired set dose AD, and proceeds to the next step SP8.

  However, the variable G represents a target value of one discharge amount in the infusion pump 44, and is specifically 0.025 [μl]. The variable f is the operation cycle of the diaphragm 64, specifically 50 [Hz].

  For example, if the set dose AD is 1 [μl] in the basal mode, the control unit 20 calculates the operating time T as 0.8 seconds using the equation (1), and the set dose AD is 10 [μl in the bolus mode. ], The operation time T is calculated as 8 seconds according to the equation (1).

  In step SP8, the control unit 20 initializes the value of the timer t to “0”, and proceeds to the next step SP9. Incidentally, the timer t is a variable representing the time since the initialization, and is updated from time to time based on the time signal from the real time clock 71 (FIG. 12).

  In step SP9, the control unit 20 sets the voltage control signal CV to a predetermined initial value, and makes the switch 73 conductive by the control signal CS and supplies it to the programmable booster circuit 74, thereby starting the operation of the infusion pump 44. The process proceeds to the next step SP10.

  In step SP10, the control unit 20 acquires the detection signal SD from the hall element 67, and proceeds to the next step SP11.

  In step SP11, the control unit 20 determines whether or not the peak voltage VSD of the detection signal SD is larger than 1 [Vp-p], that is, whether or not the displacement width of the diaphragm 64 is larger than 6 [μm]. If a positive result is obtained here, this means that the displacement width of the diaphragm 64 is larger than 6 [μm], and the discharge amount of the chemical solution by one operation in the infusion pump 44 is the target value of 0.025 [μl]. Than that. At this time, the control unit 20 proceeds to the next step SP12.

  In step SP12, the control unit 20 reduces the voltage applied to the piezoelectric element 65 in the next stroke by reducing the value of the voltage control signal CV supplied to the programmable booster circuit 74 by a predetermined width, and the next time in the injection pump 44. The amount of the chemical discharged by the stroke operation is reduced by a necessary amount, and the process proceeds to the next step SP15.

  On the other hand, if a negative result is obtained in step SP11, the control unit 20 moves to next step SP13, where the peak voltage VSD of the detection signal SD is smaller than 1 [Vp−p], that is, the displacement width of the diaphragm 64 is 6. It is determined whether it is smaller than [μm]. If a positive result is obtained here, this means that the displacement width of the diaphragm 64 is smaller than 6 [μm], and the discharge amount of the chemical liquid by one operation in the infusion pump 44 is a target value of 0.025 [μl]. Less than that. At this time, the control unit 20 proceeds to the next step SP14.

  In step SP14, the control unit 20 increases the voltage applied to the piezoelectric element 65 in the next stroke by increasing the value of the voltage control signal CV supplied to the programmable booster circuit 74 by a predetermined width. The amount of the chemical solution discharged by the stroke operation is increased by a necessary amount, and the process proceeds to the next step SP15.

  On the other hand, if a negative result is obtained in step SP13, this means that the displacement width of the diaphragm 64 is approximately 6 [μm], and the discharge amount of the chemical liquid by one operation in the infusion pump 44 is the target value of 0.025. Since it is [μl], it indicates that it is not necessary to change the value of the voltage control signal CV. At this time, the control unit 20 sets the value of the voltage control signal CV in the next stroke to the same value as the current one, and proceeds to the next step SP15.

  In step SP15, the control unit 20 determines whether or not the value of the timer t, that is, the elapsed time from the start of the drug solution administration operation is equal to or longer than the operation time T. If a negative result is obtained here, this means that the dose of the drug solution after the start of the operation of the infusion pump 44 has not reached the set dose AD, and the drug solution administration operation should be continued. . At this time, the control unit 20 returns to step SP10 again.

  On the other hand, if a positive result is obtained in step SP15, this means that the dose of the drug solution after the start of the operation of the infusion pump 44 has reached the set dose AD, and the drug solution administration operation should be terminated. ing. At this time, the control unit 20 proceeds to the next step SP16.

  In step SP16, the control unit 20 makes the switch 73 non-conductive by the control signal CS and stops the supply of the voltage control signal CV to the programmable booster circuit 74, thereby terminating the operation of the infusion pump 44 and returning to step SP1. Return.

  On the other hand, if an affirmative result is obtained in step SP2, this indicates that the current time is the preset operation end time, and therefore the chemical solution administration process should be terminated. The process proceeds to the next step SP17 and the series of chemical solution administration processing procedure RT1 is completed.

  As described above, when the infusion pump 44 is operated, the control unit 20 increases or decreases the voltage control signal CV based on the comparison result between the detection signal SD and the target voltage (1 [Vp-p]), thereby discharging the chemical liquid. Is adjusted to a target value of 0.025 [μl].

[3. Puncture device]
Next, the puncture device 3 (FIG. 1) will be described. The puncture device 3 includes an upper operation unit 81 and a lower hub unit 82, as shown in a sectional view in FIG.

  Incidentally, in the drug solution administration device 1, it is assumed that the hub unit 82 is exchanged at every puncture operation from the viewpoint of hygiene and the like, while the operation unit 81 is used a plurality of times from the viewpoint of cost and the like. Assumed.

[3-1. Configuration of operating unit]
The operation unit 81 which is the upper part of the puncture device 3 is configured around a housing 83. The casing 83 is configured in a cylindrical shape with the central axis directed in the vertical direction, and a large cavity is formed in the casing so as to penetrate vertically.

  At the lower end of the housing 83, an aperture 83A is formed by reducing (i.e., reducing) the outer diameter from the upper portion. In addition, an inner projecting portion 83 </ b> B projecting from the periphery toward the inside is provided on the inner peripheral surface side of the upper and lower portions of the housing 83.

  A first relay body 84 and a puncture spring 85 are incorporated between the throttle portion 83 </ b> A and the inner protrusion 83 </ b> B inside the housing 83. The first relay body 84 is configured around a flat cylindrical base portion 84A with the central axis directed in the up-down direction, and the outer peripheral surface of the housing 83 is slid on the inner peripheral surface of the housing 83, whereby The body 83 can move up and down.

  On the lower surface of the base portion 84A, a plurality of lower arm portions 84B are erected downward. The lower arm portion 84B is disposed along a virtual circumference surrounding the central axis of the base portion 84A on the lower surface of the base portion 84A, and has flexibility as a whole. Further, an engaging portion 84BX protrudes inward from the tip of each lower arm portion 84B.

  A plurality of upper arm portions 84C are provided upright on the upper surface of the base portion 84A. The upper arm portion 84C is arranged along a virtual circumference surrounding the central axis of the base portion 84A on the upper surface of the base portion 84A, and has flexibility as a whole. Further, an engaging portion 84CX protrudes outward from the tip of each upper arm portion 84C. Furthermore, a through hole 84D penetrating vertically is formed in the center of the base portion 84A.

  A puncture spring 85 is positioned above the base portion 84A. The puncture spring 85 is a so-called coil spring, and is sandwiched between the upper surface of the base portion 84A and the inner protrusion 83B of the housing 83 while being compressed in the vertical direction from the natural state in the housing 83. For this reason, the puncture spring 85 is configured to urge the first relay body 84 downward with respect to the inner protrusion 83B of the housing 83 by the action of the restoring force.

  A spiral thread groove 83 </ b> C is formed on the outer peripheral surface slightly above the throttle portion 83 </ b> A of the housing 83. The thread groove 83C is screwed into a thread groove 11S (FIG. 2) formed on the inner peripheral surface of the hole 11H in the upper housing 11 of the main body 2.

  Further, a through hole 83D penetrating between the inside and the outside is formed in a predetermined one direction side as viewed from the central axis slightly above the inner projecting portion 83B in the housing 83.

  A lock pin 86 is inserted into the through hole 83D. The lock pin 86 is formed in an elongated cylindrical shape along the radial direction from the central axis of the housing 83. An inclined surface 86 </ b> A is formed at the inner end of the lock pin 86 so that the lower side is separated from the central axis of the housing 83 than the upper side. A claw-like portion 86 </ b> B extends upward at the outer end of the lock pin 86.

  A lock spring 87 is provided around the lock pin 86. The lock spring 87 is a so-called coil spring, and is inserted into the lock pin 86 and has one end fixed to the peripheral side surface of the housing 83 and the other end fixed to the lock pin 86. The lock spring 87 has a relatively short natural length and is attached in a state of being extended from the natural length, thereby urging the lock pin 86 toward the central axis of the housing 83 by the action of a restoring force. .

  Further, two bearing projections 83E are erected outwardly slightly above the through hole 83D on the peripheral side surface of the housing 83. Each bearing projection 83E is provided with a shaft hole penetrating substantially along the tangential direction of the outer peripheral surface of the housing 83.

  A puncture lever 88 is sandwiched between the two bearing projections 83E. The puncture lever 88 is configured by an operation portion 88A made of a long plate-like member inclined from the vertical direction and a transmission portion 88B made of a long plate-like member inclined from the vertical direction in the opposite direction to the operation portion 88A. . That is, the puncture lever 88 joins the operation part 88A and the transmission part 88B so that the plate surfaces intersect each other at a predetermined angle.

  Further, the puncture lever 88 is provided with a thin cylindrical rotation shaft 88C at both ends of the joint portion between the operation portion 88A and the transmission portion 88B. The puncture lever 88 is rotatably held with respect to the housing 83 by inserting the rotation shaft 88C through the shaft hole of the bearing projection 83E. In other words, the puncture lever 88 is configured such that the transmission unit 88B is separated from the housing 83 when the operation unit 88A is close to the housing 83, and conversely, the transmission unit 88B is attached to the housing 83 when the operation unit 88A is moved away from the housing 83. Proximity.

  Further, an operation spring 89 is sandwiched between the operation portion 88 A of the puncture lever 88 and the housing 83. The operation spring 89 is sandwiched between the operation unit 88A and the housing 83 in a state of being slightly compressed from the natural length, and moves the operation unit 88A away from the housing 83 by the action of an extension force (restoring force). Energized in the direction.

  In other words, when no external force is applied, the puncture lever 88 is caused by the restoring force of the lock spring 87 acting on the transmission portion 88B via the lock pin 86 and the extension force of the operation spring 89 acting on the operation portion 88A. The operation portion 88A is biased in the direction of arrow R2, which is a direction in which the operation portion 88A is pulled away from the housing 83.

  A pull-out operation unit 90 is provided on the upper side of the housing 83. The drawing operation unit 90 is configured around a cylindrical portion 90A. The outer diameter of the cylindrical portion 90A is slightly smaller than the inner diameter of the housing 83, and the cylindrical portion 90A can be slid vertically with respect to the housing 83 by being inserted into the housing 83. Has been made.

  By the way, a vertically elongated groove 83F is formed in a range extending from slightly above the through hole 83D on the inner peripheral surface of the housing 83 to the vicinity of the upper end of the housing 83.

  Correspondingly, a regulation projection 90B is projected from the lower end of the cylindrical portion 90A. The restriction projection 90 </ b> B is fitted into the groove 83 </ b> F of the housing 83, thereby restricting the movement range when sliding with respect to the housing 83.

  Near the upper end of the cylindrical portion 90A, a grip portion 90C having an outer diameter that is slightly larger than the cylindrical portion 90A and closing the upper side is formed. A step is formed between the grip portion 90C and the cylindrical portion 90A, and when the patient grips the cylindrical portion 90A and applies an upward force to pull the pull-out operation portion 90 upward, the finger moves. Even if it slips, the finger is caught in this step, so that the force applied upward is received.

  A support column 90D is erected downward substantially at the center of the lower surface of the upper portion of the grip 90C. The column portion 90D is formed in a column shape that is elongated in the vertical direction, and is positioned substantially at the center of the cylindrical portion 90A. That is, the support column 90D is positioned substantially at the center of the casing 83 when the pulling operation unit 90 is inserted into the casing 83.

  The support column 90D is formed to be relatively long in the vertical direction, and when the pulling operation unit 90 is inserted to the lowest position with respect to the housing 83, that is, the restriction projection 90B is positioned at the lowermost end of the groove 83F. Sometimes, the lower end can reach the vicinity of the throttle portion 83A. In addition, the lower end of the support column 90D has a holding groove for holding a puncture needle, which will be described later, or a conical cylindrical spring material with a bottom surface having an inner diameter slightly larger than the outer diameter of the needle, and a comb-shaped vertical groove. A puncture needle holding portion 90E in which is engraved is formed.

  Incidentally, the outer diameter of the support column 90D is smaller than the inner diameter of the through hole 84D that vertically penetrates the base 84A of the first relay body 84. For this reason, the support column 90D can reach the lower end thereof below the lower surface of the base 84A without interfering with the first relay body 84.

[3-2. Hub unit configuration]
The hub unit 82 is configured around the hub 91. The hub 91 is formed in a cylindrical shape as a whole, and an internal space 91S is formed inside by a peripheral side portion 91A forming a peripheral side portion and a bottom portion 91B forming a bottom portion, and the upper side is released. ing. As will be described later, the hub 91 is configured to store a chemical in the internal space 91S.

  The inner side surface of the peripheral side portion 91A, that is, the peripheral side surface of the internal space 91S is formed smoothly. The upper surface of the bottom portion 91B, that is, the bottom surface of the internal space 91S forms a downward conical surface, and the center side is located below the outer peripheral side.

  A bottom hole 91BH that penetrates the center portion in the vertical direction is formed in the bottom portion 91B. A short cylindrical sleeve holding portion 91C projects downward from the bottom surface side of the bottom portion 91B. A center hole 91CH that penetrates in the vertical direction and communicates with the bottom hole 91BH is formed in the center of the sleeve holding portion 91C.

  A cylindrical catheter tip 92 is attached to the lower side of the hub 91 so as to be in close contact with the inside of the bottom hole 91BH of the bottom part 91B and the center hole 91CH of the sleeve holding part 91C.

  The catheter tip 92 is made of a flexible material and is formed in a hollow tubular shape. The catheter tip 92 communicates with the internal space 91S of the hub 91 on the upper end side, and communicates with the external space on the lower end side. For this reason, the catheter tip 92 is configured to allow the drug solution stored in the internal space 91 </ b> S of the hub 91 to reach the skin under the condition that the lower end reaches the skin of the patient as will be described later.

  A plug 93 is provided inside the hub 91. The plug body 93 is configured around a flat cylindrical column part 93A. The peripheral side surface of the cylindrical portion 93A is formed smoothly and is in contact with the inner side surface of the peripheral side portion 91A. Therefore, the plug body 93 can move in the vertical direction in the hub 91 by sliding the circumferential side surface of the cylindrical portion 93A along the inner side surface of the circumferential side portion 91A when an external force in the vertical direction is applied. .

  On the other hand, a restricting portion 91D that protrudes inward is provided in the vicinity of the upper end of the inner peripheral surface of the peripheral side portion 91A of the hub 91. The restricting portion 91D restricts the upward movement range of the plug body 93 by contacting the upper surface of the plug body 93 when the plug body 93 is moved upward in the hub 91. ing.

  Further, the plug body 93 is made of a material having elasticity such as latex or elastomer rubber, and the peripheral side surface of the cylindrical portion 93A is in close contact with the inner peripheral surface of the peripheral side portion 91A. For this reason, the plug 93 separates the space below the upper side of the cylindrical portion 93A and the space above the cylindrical portion 93A in the internal space 91S both when the hub 91 is stationary and when moving vertically. In addition, the flow of gas or liquid between both spaces can be prevented.

  Further, the lower surface of the cylindrical portion 93A corresponds to the upper surface of the bottom portion 91B, and the center portion is a conical surface protruding downward. For this reason, when the plug body 93 is positioned at the lowest position in the internal space 91S, the lower surface of the columnar portion 93A is brought into contact with the upper surface of the bottom portion 91B, and the space between the lower surface of the columnar portion 93A and the upper surface of the bottom portion 91B ( Hereinafter, the volume of the lower space 91SL) is substantially zero.

  Incidentally, the plug body 93 is pushed down to the lowermost part in the internal space 91S at the time of manufacture, and the volume of the lower space 91SL is substantially zero in the initial state.

  Further, a plurality of upper arm portions 93B are erected on the plug body 93 from the upper surface of the cylindrical portion 93A upward. The upper arm portion 93B is disposed along a virtual circumference surrounding the central axis of the cylindrical portion 93A on the upper surface of the cylindrical portion 93A, and has flexibility as a whole. Further, at the tip of each upper arm portion 93B, an engaging portion 93BX protrudes inward.

  Incidentally, on the outer peripheral surface of the peripheral side portion 91A of the hub 91, three groove portions 91E, 91F, and 91G are provided along the circumferential direction so as to be spaced apart from each other in the vertical direction. O-rings 94 and 95 are fitted in the lower groove portion 91E and the upper groove portion 91G, respectively.

  The central groove portion 91F is located above and below the restricting portion 91D so as to be positioned below the lower surface of the columnar portion 93A when the plug 93 is moved to the uppermost position and comes into contact with the restricting portion 91D. A position with respect to the direction is defined. Further, a side hole 91H penetrating the circumferential side portion 91A is formed in the bottom portion of the groove portion 91F.

  A cylindrical second relay body 96 is provided above the plug body 93. On the outer peripheral side of the second relay body 96, grooves 96B and 96C along the circumferential direction are formed in the vicinity of the lower end and the upper end, respectively.

  When the second relay body 96 is pressed against the plug body 93 from above the plug body 93 so that the central axes thereof are aligned, the lower end of the second relay body 96 is brought into contact with the upper surface of the plug body 93 and the upper arm portion 93B is engaged. The joining portion 93BX is engaged with the groove portion 96B.

  At this time, the second relay body 96 is integrated with the plug body 93, and when a force is applied in a direction in which the second relay body 96 is separated from each other, the engagement of the upper arm portion 93B with the groove portion 96B is released and the plug body 93 is released. And can be separated.

  Further, when the hub unit 82 is approached upward from the lower side of the operation unit 81 so that the centers thereof are aligned with each other, the upper end of the second relay body 96 is located between the lower arm portions 84B of the first relay body 84. The engaging portion 84BX is engaged with the groove portion 96C.

  At this time, the second relay body 96 is relatively strongly integrated with the first relay body 84, and only when a very strong force is applied in a direction to separate them from each other, the lower arm portion 84B with respect to the groove portion 96C. The engagement can be released and the first relay body 84 can be separated.

  In addition, a needle support 96D is provided inside the second relay body 96. The needle support 96D has a thick cylindrical shape, and has a hole penetrating in the vertical direction at the center thereof. The puncture needle 97 is positioned at the center of the second relay body.

  A puncture needle 97 is provided at the center of the hub unit 82. The puncture needle 97 is configured in an elongated cylindrical shape, and its lower end is sharply formed. In the initial state, the puncture needle 97 is inserted through the center of the second relay body 96, penetrates through the center of the cylindrical portion 93A of the plug body 93, and is further inserted into the tube of the catheter tip 92, and the lower end of the puncture needle 97 is inserted into the catheter. The chip 92 is exposed from the lower end.

  Incidentally, the cylindrical portion 93A of the plug 93 is not provided with a hole for allowing the puncture needle 97 to pass therethrough. For this reason, the plug 93 is penetrated while forming a new hole by the puncture needle 97 being pierced from the lower end with respect to the upper surface of the cylindrical portion 93A.

  Further, the cylindrical portion 93A of the plug body 93 can close the formed hole by the elasticity of the constituent material when the puncture needle 97 is pulled out, and the space below the cylindrical portion 93A in the internal space 91S. The flow of gas and liquid between the upper space can be continuously prevented.

[3-3. Puncture action]
Next, the puncturing operation of the puncture device 3 will be described. As shown in FIG. 14, the puncture apparatus 3 is initially in a state where the operation unit 81 and the hub unit 82 are separated from each other, and are integrated as shown in FIG. .

  At this time, the hub unit 82 is gradually lifted upward from below the operating unit 81 to engage the lower arm portion 84B of the first relay body 84 and the second relay body 96, and to The upper end of the relay body 96 is brought into contact with the lower surface of the base portion 84 </ b> A of the first relay body 84.

  The hub unit 82 continues to be lifted upward, thereby applying an upward force to the first relay body 84 via the second relay body 96. Thereby, the first relay body 84 moves upward in the housing 83 while compressing the puncture spring 85.

  Eventually, the hub unit 82 causes the upper end of the peripheral side portion 91A of the hub 91 to reach the vicinity of the throttle portion 83A of the housing 83. At this time, the first relay body 84 slightly moves the lock pin 86 outward while sliding the engaging portion 84CX of the upper arm portion 84C with the inclined surface 86A of the lock pin 86, and then lowers the lower end of the engaging portion 84CX. Is moved upward from the upper end of the inclined surface 86 </ b> A, the lock pin 86 is moved to the center axis side of the housing 83 by the lock spring 87 and engaged with the lock pin 86.

  As a result, the puncture spring 85 is maintained in a compressed state between the upper surface of the base portion 84A of the first relay body 84 and the inner protruding portion 83B of the housing 83.

  At this time, the upper end of the puncture needle 97 is inserted into the puncture needle holding portion 90E provided at the lower end of the column portion 90D of the pulling operation portion 90, and is held by the puncture needle holding portion 90E.

  On the other hand, the main body 2 is subjected to a priming operation in which the reservoir 41 is filled with a chemical solution corresponding to 72 hours, and the chemical solution is filled in the pipe to the hole 49H. In addition, the preparation of the medication process is completed in the main body 2 by storing the drug solution administration time and the dose in an internal memory by a controller (not shown).

  Subsequently, in the puncture device 3, the hub 91, the catheter tip 92, etc., which are the lower end portions, are inserted into the mounting portion 2N of the main body 2 with respect to the main body 2 that has been prepared for the medication processing in this way, and further the watch Rotated in the direction. Thereby, in the puncture device 3, the screw groove 83C of the housing 83 is screwed with the screw groove 11S (FIG. 2) of the hole 11H in the upper housing 11, and is fixed to the main body 2. Thus, the main-body part 2 to which the puncture apparatus 3 was attached is affixed with the adhesive tape 2S with the lower surface facing the patient's skin.

  Next, the puncture device 3 is pushed in a direction in which the operation portion 88A of the puncture lever 88 is close to the housing 83 by the operation of the patient or the like. At this time, the transmission portion 88B of the puncture lever 88 moves the lock pin 86 so as to be pulled out from the housing 83 and releases the engagement with the engagement portion 84CX of the first relay body 84.

  Thereby, as shown in FIG. 15 (B), the puncture apparatus 3 applies the restoring force of the puncture spring 85, and the first relay body 84, the second relay body 96, the hub 91, the catheter tip 92, the plug body 93, The puncture needle 97 and the extraction operation unit 90 are moved downward together.

  Along with this, the puncture needle 97 is punctured into the patient's skin together with the catheter tip 92 to allow the tip of the catheter tip 92 to reach subcutaneously. The hub 91 is in contact with the bottom portion 12CA of the lower housing 12 in the mounting portion 2N, and the groove portion 91F is positioned at substantially the same height as the hole portion 49H of the middle cylindrical portion 49.

  At this time, the hub 91 causes the groove portion 91F communicating with the side hole 91H to communicate with the hole portion 49H. Therefore, the hub 91 can communicate the side hole 91H and the hole portion 49H via the groove portion 91F even if the side hole 91H faces a different direction from the hole portion 49H with respect to the central axis.

  At this time, the O-rings 94 and 95 seal the space between the outer peripheral surface of the hub 91 and the inner peripheral surface of the mounting portion 2N in the upper and lower portions of the hole 49H. Thereby, a flow path is formed from the pipe 48 to the internal space 91S through the hole 49H, the groove 91F, and the side hole 91H.

  Next, as shown in FIG. 16A, the puncture device 3 is pulled upward with respect to the housing 83 by the operation of the patient or the like. At this time, the pull-out operation unit 90 keeps the puncture spring 85 extended, and without moving the first relay body 84, the second relay body 96, the plug body 93, the hub 91, and the catheter tip 92, the puncture needle holding section. The puncture needle 97 held by 90E is lifted upward, and the tip is pulled out of the patient's skin. Thereby, the catheter tip 92 is in a state where the lower end is left under the skin.

  Further, the extraction operation unit 90 also extracts the puncture needle 97 held by the puncture needle holding unit 90E from the plug 93. At this time, as described above, the plug 93 closes the hole through which the puncture needle 97 is inserted by the action of the elastic body, and maintains the airtightness of the lower space 91SL.

  Finally, the puncture device 3 is rotated counterclockwise with respect to the main body 2 by an operation of a patient or the like, whereby a screw groove 83C of the housing 83 and a screw groove 11S of the hole 11H in the upper housing 11 are formed. The screwing is released and the main body 2 is detached as shown in FIG.

  At this time, in the puncture device 3, the first relay body 84 abuts on the throttle portion 83 </ b> A in the housing 83, and the engaging portion 84 </ b> BX of the lower arm portion 84 </ b> B in the first relay body 84 is the groove portion 96 </ b> C of the second relay body 96. The engaging portion 93BX of the upper arm portion 93B of the plug body 93 is engaged with the groove portion 96B of the second relay body 96. The puncture device 3 holds the puncture needle 97 by the puncture needle holding unit 90E of the pulling operation unit 90.

  For this reason, when an upward force is applied to the housing 83 by a patient or the like, the puncture device 3 pulls the plug 93 upward via the first relay body 84 and the second relay body 96, and the lower space The volume of 91SL is gradually expanded. At this time, since the lower space 91SL is not in communication with the outside, a negative pressure is generated as the volume increases.

  Eventually, the plug body 93 stops when the upper surface of the cylindrical portion 93A comes into contact with the restricting portion 91D, so that the upward movement is restricted and stopped, and the puncture device 3 is continuously lifted, whereby the engaging portion of the upper arm portion 93B. The engagement between 93BX and the groove 96B of the second relay body 96 is released.

  At this time, since the bottom surface of the cylindrical portion 93A is higher than the side hole 91H drilled in the peripheral side portion 91A of the hub 91, the plug body 93 communicates the lower space 91SL with the side hole 91H. The groove portion 91F, the hole portion 49H, and the pipe 48 are communicated. Thereby, the piping 48 is communicated with the catheter tip 92 through the hole 49H, the groove 91F, the side hole 91H, and the lower space 91SL.

  Accordingly, the main body 2 includes a groove portion 91F that is surrounded by the O-ring 94 and the O-ring 95 of the hub 91 with the chemical solution supplied from the hole portion 49H due to the negative pressure generated in the lower space 91SL in the hub 91. Priming can be performed by filling the sealed space and the lower space 91SL.

  That is, when the puncture device 3 is pulled away from the main body 2, the puncture device 3 is lifted up to a position where the plug 93 is brought into contact with the restricting portion 91 </ b> D in the hub 91 to increase the volume of the lower space 91 </ b> SL. The second relay body 96 and the puncture needle 97 are integrated with the operation unit 81 while being left on the mounting portion 2N side of the main body portion 2 and removed from the main body portion 2.

  Thereafter, the main body 2 fills the catheter tip 92 with a chemical solution by operating the infusion pump 44 (FIG. 3, FIG. 8, etc.) for a specified time so as to discharge a specified amount under the control of the control unit 20.

[4. Operation and effect]
In the above configuration, the main body 2 of the drug solution administration device 1 according to the present embodiment is provided with the detection unit 69 including the magnet 68 and the Hall element 67 in the infusion pump 44.

  The magnet 68 is attached to the piezoelectric element 65 that drives the diaphragm 64, and is displaced integrally with the diaphragm 64. The Hall element 67 is attached to a portion of the highly rigid substrate 66 fixed to the base portion 61 through the columnar portion 61P so as to face the magnet 68, and is displaced even when the diaphragm 64 is vibrated. It stops at a certain position.

  In the Hall element 67, when the magnet 68 is displaced integrally with the diaphragm 64 by the piezoelectric element 65, the surrounding magnetic field is changed by the magnet 68, and the resistance value is changed.

  For example, when the Hall element 67 and a predetermined resistor are connected to a series circuit, when a constant voltage is applied to the circuit by a constant voltage source of the infusion pump control circuit, the change in the resistance value of the Hall element 67 is It can be detected as a voltage drop.

  The Hall element 67 amplifies this voltage drop to generate a detection signal SD in which the displacement of the diaphragm 64 appears as a voltage change. For this reason, the control unit 20 can indirectly recognize the displacement width of the diaphragm 64 based on the voltage of the detection signal SD.

  Further, the control unit 20 converts the voltage control signal CV into an analog value by the infusion pump control circuit 70 (FIG. 12) and supplies the analog value to the programmable booster circuit 74. As a result, the programmable booster circuit 74 supplies the piezoelectric element 65 with a driving pulse composed of a rectangular wave of 50 [Hz] that has been changed to an amplitude corresponding to the voltage control signal CV.

  Furthermore, the control unit 20 increases or decreases the value of the voltage control signal CV by feedback control so that the voltage of the detection signal SD approaches 1 [Vp−p] that is the target voltage.

  As a result, the control unit 20 can bring the displacement width of the diaphragm 64 closer to the target distance of 6 [μm], so that the injection amount per one stroke (hereinafter referred to as a unit discharge amount) is applied to the diaphragm 64 in the infusion pump 44. ) Can be adjusted to the target discharge amount of 0.025 [μl].

  Further, the control unit 20 fixes the cycle of the voltage control signal CV to 20 [ms]. Therefore, the control unit 20 changes the number of strokes per hour of the diaphragm 64 and changes the discharge amount per hour in the infusion pump 44 by controlling the time when the switch 73 is “ON” by the control signal CS. Can be made.

  Therefore, the control unit 20 can adjust the unit discharge amount to the target discharge amount of 0.025 [μl] by using the detection signal SD to bring the displacement width of the diaphragm 64 close to the target distance. By simply controlling the CV supply time, the dose of the drug solution can be adjusted with high accuracy.

  In general, the diaphragm pump has a problem that it is difficult to keep the flow rate constant even when a rectangular wave having a constant amplitude is supplied to the piezoelectric element. Therefore, in a device using a diaphragm pump, a method of detecting the flow rate using a large and expensive high-accuracy flow meter (flow sensor) to control the frequency of the rectangular wave, or making the diaphragm pump have a constant hydraulic pressure. It is conceivable to control the flow rate using a highly accurate throttle. However, in any of the methods, there is a possibility that the size of the apparatus is increased, the power consumption is increased, and the cost is increased.

  In this regard, in the present embodiment, the actual discharge amount from the infusion pump 44 is not measured, but the displacement amount of the diaphragm 64 is detected and feedback controlled by the detection unit 69 that is a combination of the Hall element 67 and the magnet 68. As a result, the entire main body 2 can be made extremely small, and the cost can be kept relatively low without increasing the power consumption.

  According to the above configuration, the main body part 2 of the drug solution administration device 1 according to the present embodiment is provided with the detection unit 69 including the magnet 68 and the hall element 67 in the infusion pump 44, and the hall element 67 sets the displacement width of the diaphragm 64. A detection signal SD having a corresponding amplitude is generated. Further, the main body 2 indirectly recognizes the displacement width of the diaphragm 64 based on the voltage of the detection signal SD and changes the voltage of the voltage control signal CV to perform feedback control so that the detection signal SD approaches the target voltage. The displacement width of the diaphragm 64 can be made closer to the target distance, and the unit discharge amount can be adjusted to the target discharge amount. Therefore, the main body 2 can discharge the target amount of the chemical solution a desired number of times by controlling the supply time of the voltage control signal CV whose period is fixed, so that the dose of the chemical solution can be adjusted with high accuracy. .

[5. Other Embodiments]
In the above-described embodiment, the detection unit 69 that combines the Hall element 67 and the magnet 68 detects the displacement width of the diaphragm 64 based on the detection signal SD in which the amount of change in the magnetic field appears in the voltage. Said.

  However, the present invention is not limited to this, and the displacement width of the diaphragm 64 may be detected by a detection unit that detects various physical quantities such as a sound wave and a capacitor capacity.

  Further, in the above-described embodiment, the case where the piezoelectric element 65 as the displacement means is attached to the diaphragm 64 and both are vibrated as a unit has been described.

  However, the present invention is not limited to this. For example, an actuator instead of the piezoelectric element 65 may be attached to the base 61 of the infusion pump 44, and only the diaphragm 64 may be vibrated by this actuator.

  In the above-described embodiment, the case where both the valve 62 functioning as the suction valve of the injection pump 44 and the valve 63 functioning as the discharge valve are passive valves has been described.

  However, the present invention is not limited to this. For example, in synchronization with the movement of the diaphragm 64, the suction valve is opened and the discharge valve is closed when the diaphragm is at the top dead center, and the diaphragm is displaced from the top dead center to the bottom dead center. This state is maintained for a while, and when the diaphragm is at bottom dead center, the suction valve is closed and the discharge valve is opened, and control is possible to maintain this state while the diaphragm is displaced from bottom dead center to top dead center. An active valve that opens and closes by a piezoelectric element or the like may be used.

  Further, in the embodiment described above, the cycle of the drive signal S2 supplied from the programmable booster circuit 74 to the piezoelectric element is fixed to 50 [Hz], and the injection pump 44 supplies the voltage control signal CV from the control unit 20 according to the supply time. The case where the discharge amount of the chemical was adjusted was described.

  However, the present invention is not limited to this. Instead of changing the amplitude of the drive signal S2, the frequency of the drive signal S2 is determined according to the comparison result between the peak voltage VSD of the detection signal SD and the target voltage 1 [Vp-p]. It is also possible to adjust the discharge amount of the chemical solution from the infusion pump 44 by changing.

  Further, in the above-described embodiment, when 1 [μl] is administered per hour in the basal mode, 1 [μl] drug solution is intensively administered once every hour for about 0.8 seconds. Then, the case where the intermittent operation such as the rest for the remaining 59 minutes and 59.2 seconds is performed has been described.

  However, the present invention is not limited to this, and in the basal mode, for example, it is divided into arbitrary unit times such as 15 minutes or 30 minutes, and a predetermined amount of the drug solution is administered every unit time so that the drug solution is administered. Also good.

  Further, in the above-described embodiment, the case where the drug solution made of insulin is caused to flow by the infusion pump 44 incorporated in the main body 2 of the drug solution administration device 1 has been described.

  However, the present invention is not limited to this, and may be applied to a diaphragm pump that is incorporated in various devices that handle liquids and flows various liquids.

  Further, in the embodiment described above, the storage space 61C as the pump chamber, the flow paths 61A and 61B as the suction flow paths, the flow paths 61D and 61E as the discharge flow paths, the valve 62 as the one-way valve, and 63, a diaphragm 64 as a diaphragm, a piezoelectric element 65 as a displacement means, an infusion pump 44 as a pump unit having a detection unit 69 as a detection unit, a reservoir 41 as a reservoir, and a control as a control unit The case where the main body 2 as a chemical solution administration device is configured with the unit 20 has been described.

  However, the present invention is not limited to this, and a pump unit having various other configurations, a suction channel, a discharge channel, a one-way valve, a diaphragm, a displacement means, and a pump unit having a detection unit, You may make it comprise a chemical | medical solution administration apparatus with a reservoir | reserver and a control part.

  The present invention can be applied, for example, when a chemical solution is supplied using a diaphragm pump.

DESCRIPTION OF SYMBOLS 1 ... Chemical solution administration apparatus, 2 ... Main-body part, 3 ... Puncture apparatus, 20 ... Control part, 41 ... Reservoir, 44 ... Infusion pump, 51 ... Bubble removal pump, 61 ... Base part, 61A, 61B, 61D, 61E: Flow path, 61C: Storage space, 61P: Columnar part, 62, 63: Valve, 64: Diaphragm, 65: Piezoelectric element, 66: Substrate, 67: Hall element , 68... Magnet, 69... Detection unit, 70... Infusion pump control circuit, 74... Programmable booster circuit, AD... Set dose, CV ... voltage control signal, S1. Drive signal, SD: Detection signal.

Claims (6)

A chemical administration device for administering a chemical into a user's body,
A pump unit including a pump for feeding a chemical into the user's body;
A reservoir for storing the drug solution;
A control unit for controlling the pump,
The pump part is
A pump chamber for temporarily storing chemicals;
A suction flow path communicating between the pump chamber and the reservoir;
A discharge flow path that communicates between the pump chamber and a catheter whose tip has reached the user's body;
One-way valves respectively provided in the suction flow path and the discharge flow path;
A diaphragm provided at a side portion of the pump chamber, and changing a volume of the pump chamber;
Displacement means for displacing the diaphragm based on a set displacement amount;
A detection unit for detecting a displacement amount of the diaphragm,
The controller is
The drug solution administration device characterized by controlling the displacement means so as to eliminate the difference between the displacement amount detected by the detection unit and the set displacement amount. The controller is
The medicinal-solution administration device according to claim 1, wherein an increase / decrease amount of the set displacement amount is changed according to a difference between the displacement amount detected by the detection unit and the set displacement amount. The controller is
The drug solution administration device according to claim 2, wherein the diaphragm is displaced during a predetermined operation period of a predetermined unit time, and the diaphragm is stopped during the other stop period. The displacement means is
It is a piezoelectric element that changes the amount of displacement according to the applied voltage,
The controller is
The drug solution administration device according to claim 1, wherein a voltage applied to the piezoelectric element is controlled. The detector is
The drug solution administration device according to claim 1, further comprising: a magnet that is displaced together with the diaphragm; and a hall element that detects a change in a magnetic field by the magnet. A pump unit including a pump for feeding a chemical solution into a user's body, a reservoir for storing the chemical solution, and a control unit for controlling the pump, wherein the pump unit temporarily stores the chemical solution A pump chamber that communicates between the pump chamber and the reservoir, a discharge channel that communicates between the pump chamber and a catheter whose tip has reached the body of the user, A one-way valve provided in each of the suction flow path and the discharge flow path, a diaphragm provided on a side portion of the pump chamber and changing the volume of the pump chamber, and a displacement for displacing the diaphragm based on a set displacement amount A drug solution administration method for a drug solution administration device comprising:
A detection step of detecting a displacement amount of the diaphragm by a predetermined detector;
And a control step of controlling the displacing means so as to eliminate a difference between the displacement amount and the set displacement amount by a predetermined control unit.