Implantable drug delivery device

Abstract

The invention discloses an implantable drug delivery device. The implantable drug delivery device comprises a drug storage and infusion assembly implanted in vivo and a control assembly in vitro. The medicine storage and infusion assembly comprises a medicine storage unit, an infusion unit and a pipeline unit, the medicine storage unit comprises a pressure cavity, a medicine storage bag in the pressure cavity and a magnetic positioner, the infusion unit comprises a medicine feeding cavity, a funnel-shaped baffle is arranged on the upper half portion of the infusion unit, a medicine outlet is formed in the bottom end of the infusion unit, and a biconical magnetic valve is arranged in the middle of the infusion unit. The diameter width of the biconical magnetic valve is designed to only move between the two medicine outlets, and the two medicine outlets are not blocked at the same time; the pipeline unit comprises an access pipeline communicated with the medicine storage bag and the medicine feeding cavity and a medicine release pipeline communicated with the bottom end medicine outlet and the target organ. Only the non-circuit part is implanted into the human body, the size of foreign matter implanted into the human body is reduced, the comfort of the human body is higher, the in-vivo implanted assembly part does not need a battery to provide energy, and the defect that the battery needs to be taken out of the human body again to be replaced after the power of the current implanted drug delivery device is exhausted is overcome.

Description

Technical Field

[0001] The invention belongs to the technical field of medical devices and relates to an implantable drug delivery device. Background Art

[0002] Implantable infusion therapy is a new and revolutionary way of drug administration. Through minimally invasive surgery, doctors implant an implantable drug infusion pump that can store drugs and adjust the flow rate into the body, usually under the skin of the chest and abdominal wall, and inject the drugs directly into the target organ through a soft catheter, which can achieve fast, continuous and convenient medication. For example, after the intrathecal drug infusion system of Medtronic is implanted in the human body, only 1 / 300 of the dose of oral analgesics is given to the corresponding pain center at the end of the catheter to achieve better analgesic effect and reduce side effects. Medtronic's intrathecal drug infusion system and patent CN216091721U are all based on this concept to achieve the purpose of treatment. Medtronic's products can currently accurately control the injection of at least 48μL of liquid medicine on demand every day.

[0003] However, the current implantable drug delivery devices require that the drug delivery power parts such as power supply, drug storage box and flow control circuit pump are directly sealed in the system and implanted in the human body, and the power generated by the battery implanted in the human body drives the drug to act on the target organ through the catheter. This type of system faces a series of problems after being implanted in the human body: first, the volume is too large. In addition to the necessary drug storage bag and catheter, it is also necessary to implant components unrelated to treatment such as batteries, control circuits and drive motors, which significantly increases the volume. After implantation in the human body, the patient feels obvious discomfort; second, the complex circuit system will inevitably face problems such as machine circuit and battery failure, and the patient will face additional pain and risks unrelated to treatment, such as the need for surgery to remove, replace or repair; in addition, this series of products on the market cannot objectively monitor the remaining amount of medicine in the implanted drug bag in the body, but only calculate the remaining amount of medicine by the set speed and medication time. When a mechanical failure occurs, such as pipeline blockage, it is impossible to detect the abnormal amount of liquid medicine in time; finally, under the premise that the inductive charging technology is not yet mature in the human body, the power of the implanted system can only provide power for a few years. After several years of power exhaustion, it is necessary to remove the battery from the human body again and replace it, which is unrelated to treatment but the patient must endure the pain of surgery. Summary of the invention

[0004] The present invention is directed to the above-mentioned problems and provides an implantable drug delivery device. The technical idea of ​​the present invention is as follows: only the non-circuit parts such as the drug storage, infusion execution part and pipeline are introduced into the human body, thereby reducing the volume of foreign bodies implanted in the human body and making the human body more comfortable. In terms of control, the control components including the power supply, magnetic generator, controller and induction receiver are integrated and arranged outside the body. When used, the skin is attached to the body (such as being designed to be fixed in the form of a belt, etc.). The power control part generates a magnetic driving force to accurately control the infusion of drugs to meet the treatment needs. It is preferred to use a constant pressure-driven pulsed drug delivery, which is more in line with the physiological process. At the same time, a magnetic positioning device is installed on the drug capsule implanted in the body, and the drug delivery situation can be objectively monitored by the in vitro applied sensor, which is safer and more accurate. The main purpose of the present invention is to solve the risk problem that the fully implanted infusion system needs to implant batteries and circuit controls that are not related to treatment in the human body, while reducing the precision but easy to fail structures such as gear rotors implanted in the human body infusion system, and solving the problem that the current implanted drug delivery system cannot objectively and real-time monitor indicators such as the amount of drugs implanted in the body and the drug delivery speed.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] The implantable drug delivery device provided by the present invention has the following technical features: it comprises a drug storage and infusion component implanted in the body and a control component arranged outside the body.

[0007] The drug storage and infusion assembly includes a drug storage unit, an infusion unit, and a pipeline unit;

[0008] The drug storage unit includes an outer shell, the interior of which is divided into a closed pressure chamber and a compressible drug storage bag; magnetic locators are arranged on the pressure chamber and the drug storage bag; the outer shell is made of an inert material that is non-magnetic and has stable physical and chemical properties in the body, and a temperature insulation layer is arranged on the inner wall; the pressure chamber is filled with a gas-liquid two-phase mixture, the drug storage bag is made of compressible rubber or hard plastic, the main body has a retractable pleated design, and a drug filling hole is arranged on the top, so that the drug solution can be repeatedly injected into the drug storage bag through skin puncture; magnetic locators are arranged on the pressure chamber and the drug storage bag.

[0009] As the drug is injected into or out of the drug storage bag, the volume of the drug storage bag will change, thereby affecting the volume in the closed pressure chamber and causing the gas-liquid phase ratio of the gas-liquid substance to change at different volumes, but the air pressure is always maintained constant, that is, the drug bag is always in a constant air pressure-driven compression state, and this constant air pressure is greater than the tissue pressure of the target organ as the driving force for the drug solution to flow out.

[0010] The infusion unit includes a drug delivery chamber, the upper part of which is provided with a funnel-shaped baffle, a drug outlet at the bottom, and a double-conical magnetic valve in the middle part. The maximum width of the double-conical magnetic valve is larger than the drug outlet of the funnel-shaped baffle and the inner diameter of the drug outlet at the bottom, and the two drug outlets are not blocked at the same time. The magnetic valve can only move up and down between the two drug outlets.

[0011] The pipeline unit includes a passage pipeline connecting the drug storage bag and the drug delivery cavity and a drug release pipeline connecting the bottom drug outlet and the target organ;

[0012] The control component comprises a shell, a power source, a magnetic force generator, a controller and an inductive receiver wirelessly connected to the inductor arranged in the shell.

[0013] Preferably, in the implantable drug delivery device provided by the present invention, the material requirements for the shell are as follows: non-magnetic conductive material but hard and able to withstand pressure and will not deform under the pressure of 37°C in the body, preferably plastic steel material.

[0014] The thermal insulation layer is made of rubber or silicone. Rubber and silicone have good thermal insulation properties and are often used as thermal insulation materials for pipes, equipment, etc., and can resist the impact of high temperature environments on equipment. In the present invention, the gas-liquid two-phase material mixture will generate or absorb heat during the gas-liquid conversion process, and the thermal insulation layer can buffer and prolong the temperature change time to prevent damage to human tissue. In the present invention, the thermal insulation layer material is preferably silicone, which is a conventional medical material and its safety is guaranteed.

[0015] The pressure chamber is filled with a gas-liquid two-phase mixture similar to a refrigerant, which has stable chemical properties and will not react chemically with the capsule material and the shell. The gas-liquid two-phase mixture is selected from fluorinated alkane, propane, trichloromonofluoromethane, butane, etc. These substances can be safely converted between gas and liquid as the external pressure changes within the constant temperature range of the human body at around 37°C.

[0016] Under the condition of 37℃ relative constant temperature in human body, as the pressure environment changes due to the change of volume of medicine bag, the gas part and liquid transform into each other to keep constant air pressure. When the pressure of medicine bag increases (the volume of medicine injected into medicine bag increases and compresses the pressure chamber part), the heat released in the process of gas conversion into liquid should be small and slow, so as not to burn the human body. When the volume of pressure chamber increases (drug liquid in medicine bag decreases slowly during infusion, the volume of medicine bag decreases slowly, and the relative volume of pressure chamber increases), part of liquid is converted into gaseous state, and heat is absorbed slowly from human body, so as not to cause frostbite. Before leaving the factory, gas and liquid substances are sealed in the pressure chamber according to the parameters required for safety and clinical treatment.

[0017] Preferably, in the implantable drug delivery device provided by the present invention, in the drug storage unit, memory silica gel is fixedly provided in the drug filling hole. The entire drug storage and infusion assembly contacts the tissue under the human skin through the top part of the memory silica gel, and the bottom part is located in the opening of the drug storage bag. The passage pipe seal passes through the pressure chamber and is sealed and connected to the opening of the drug storage bag. The top of the memory silica gel is provided with a puncture indication point, which can be accurately inserted by touch, ultrasonic positioning or using a special non-destructive puncture needle tip to touch and feel. A liquid medicine guide tube is provided inside, and a filter tank is provided at the bottom of the liquid medicine guide tube. The filter tank is flush with the bottom opening of the memory silica gel or slightly protrudes from the memory silica gel.

[0018] The memory silicone is the contact point between the infusion component and the subcutaneous tissue of the patient's skin. As the penetration point of the injection needle, a special non-destructive puncture needle can be used through the skin to repeatedly puncture the filling hole to inject additional liquid medicine to ensure continuous use after implantation. When the liquid medicine in the drug storage bag is lower than the preset amount, the injection needle passes through the skin and the memory silicone contact point to filter the liquid medicine through the liquid medicine filter tank and then inject it into the drug storage bag.

[0019] The puncture indicator point is used to guide the needle into the drug liquid guide tube. The drug liquid guide tube plays a certain temporary storage role for the drug liquid injected by the needle. The drug liquid in the tube enters the drug storage bag after being filtered through the filter tank.

[0020] Preferably, in the implantable drug delivery device provided by the present invention, the top end of the drug storage bag is fixedly arranged in the pressure chamber, and the gas-liquid two-phase material pre-sealed in the pressure chamber will generate a constant pressure, which compresses the elastic drug liquid in the drug storage bag to generate a driving pressure inside the drug liquid. In the absence of external magnetic force, the internal driving pressure is greater than the pressure of the target organ tissue in the human body. Under the action of the pressure difference, the double-conical magnetic valve is pushed to the bottom drug outlet of the drug delivery chamber to seal it.

[0021] In terms of structure, the drug storage bag is in the shape of a compressible cylindrical fold with a smooth bottom end and a serrated compressible fold in the middle column. It has a drug injection port at the top and is fixed in the pressure chamber. The constant air pressure generated by the gas-liquid two-phase mixture presses the drug storage bag to move upward and compress, generating a constant internal driving pressure that meets the requirements of clinical treatment. In the absence of external magnetic force, the internal driving pressure is greater than the pressure of the target organs in the human body, moving the double-conical magnetic valve to the bottom drug outlet of the drug delivery chamber to seal it.

[0022] In terms of materials, the drug storage capsule is made of TPE, PP, PE or PVA; these materials are non-toxic to the human body and are hard plastics. They do not generate elastic force themselves and only produce deformation and volume changes under pressure.

[0023] Preferably, in the implantable drug delivery device provided by the present invention, the positioning device is a positioning permanent magnet, a total of three, which are respectively arranged at the bottom of the drug storage bag and the top and bottom inner walls of the pressure chamber. The inductive receiver of the external part receives three position information in real time, and the controller monitors the compression degree of the drug storage bag and obtains the remaining situation of the drug solution according to the displacement change of the compressible active part of the drug storage bag obtained by the relative intensity change of the magnetic signal of the sensor, and accordingly obtains the pressure of the drug solution in the drug storage bag and the connecting pipeline and the infusion unit. At the same time, the relative position of the positioning magnet and the magnetic valve is fixed, so the sensor can calculate the position of the magnetic valve according to the magnetic lines of force of the positioning magnet. When the electromagnet part in the external control component moves to the corresponding optimal position of the magnetic valve skin, a prompt sound or a color signal light prompt is issued to facilitate the determination of the optimal position of the external component for skin application.

[0024] In addition, the position of the positioning permanent magnets on the top and bottom inner walls of the pressure chamber remains unchanged, and the positioning permanent magnet on the top of the movable part of the drug storage bag gradually changes in displacement with the output of the drug and the compression of the drug bag. When it changes to the preset displacement space, it indicates that the drug liquid reserves in the drug storage bag are insufficient and drug filling is required.

[0025] Preferably, in the implantable drug delivery device provided by the present invention, the center of the double-cone magnetic valve is a magnetic material, and the outside is wrapped with a non-magnetic and chemically stable coating that does not react with the drug solution, and the material is selected from silicone or polyethylene. The distance between the drug outlet of the funnel-shaped baffle and the bottom drug outlet is about 1.5 times the length of the double-cone magnetic valve, ensuring that the double-cone magnetic valve does not block the two drug outlets at the same time and does not react with the drug solution.

[0026] In the present invention, the volume of the lower half of the drug delivery chamber is not only able to accommodate the double-cone magnetic valve, but also preferably has a drug solution capacity of about 0.05 to 0.1 ml. The frequency and drug solution concentration are controlled to achieve the purpose of precise drug delivery that meets the actual requirements of treatment.

[0027] The double-conical magnetic valve design can ensure that the pipeline is automatically blocked in the event of an accident (for example, when a patient undergoes an MRI examination, a strong external magnetic field may cause the magnetic valve to leave the sealing port, but in this design, the upper drug outlet will be directly blocked) to prevent accidents such as excessive infusion of drug solution and backflow of body fluids (blood or cerebrospinal fluid, etc.).

[0028] Preferably, in the implantable drug delivery device provided by the present invention, in the control component, a fixing belt, a switch, a display screen, a drug injection amount setting key, a drug storage indicator light and a power indicator light are arranged on the housing. The power source is a common or rechargeable lithium battery or a power supply coil, the magnetic force generator includes an electromagnet, the controller is a microprocessor, and the magnetic induction receiver is a wireless receiver.

[0029] The fixing strap style is preferably a shoulder strap or a waist belt to improve the fixing stability; the switch is used to open the control component before administering the drug to achieve wireless communication connection between the components inside and outside the body; the display screen scrolls to display the injection time, set injection amount, and injected amount when the device is working, and displays the battery power when the device is not working; the injection amount setting key is used to set the dosage, and after the setting is completed, turn on the switch device to start working.

[0030] The working principle of the device of the present invention is as follows:

[0031] The gas partial pressure P of the gas-liquid biphase substance in the pressure chamber of the drug storage bag A (This value can be sealed and designed at the factory, and the pressure difference is greater than the tissue pressure of the target organ to drive the liquid medicine according to the treatment needs) B Pressure. The internal driving pressure P B It is greater than the pressure Pc of the target organs in the human body to achieve the purpose of driving drug delivery.

[0032] The drug administration process is as follows: start the switch, and when the microprocessor starts according to the preset program, the power supply and the magnetic generator are connected. After the magnetic generator is energized, the current gradually generates magnetic force from small to large, and its magnetic flux acts on the double-conical magnetic valve. As the current increases, the magnetic flux increases, and the electromagnetic force generated gradually increases to a driving pressure greater than the drug liquid in the drug storage bag, driving the double-conical magnetic valve to move up to block the drug outlet of the funnel-shaped baffle and then stop moving. The external control system can sense the changes in indicators such as magnetic flux and induced current and then judge that the magnetic valve has moved to the upper drug outlet, and immediately cut off the current in the electromagnet coil and the magnetic force disappears. Under the action of the pressure difference, the magnetic valve leaves the funnel-shaped upper drug outlet and moves again to the bottom lower drug outlet to seal.

[0033] In the present invention, only when the magnetic valve moves up and down for a short period of time, the upper and lower drug outlets are connected to complete drug administration under constant pressure drive. It is entirely possible to achieve the precision capacity of controlling a drug administration cycle at the microliter level by adjusting the size of the corresponding electromagnetic force according to indicators such as the subcutaneous implant thickness after the preliminary design and implantation in the human body. Clinicians can calculate the amount of drug solution given by a magnetic valve movement cycle for a specific patient based on the amount of drug solution that can be given by the manufacturer under different pressure differences and the pressure of the patient's target organ, and further adjust the drug solution concentration and drug administration frequency as well as the corresponding drug administration time plan according to the treatment needs to achieve the treatment purpose.

[0034] In the present invention, the induction receiver not only senses the changes in the positioning information of the positioning magnet and the magnetic flux current, but also can expand and install the remote control function in accordance with relevant medical safety regulations, remotely transmit the medication information to the doctor, and remotely control the medication dosage and speed adjustment.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The implantable drug delivery device of the present invention only introduces non-circuit parts such as drug storage, infusion execution part and pipeline into the human body, which not only reduces the volume of foreign objects implanted in the human body and makes the human body more comfortable, but also does not require batteries to provide energy for the implanted components in the body, thus overcoming the disadvantage that the current implantable drug delivery device needs to be taken out of the human body again to replace the battery after the power is exhausted. Without increasing the volume of the implant, the capacity of the drug that can be loaded is further increased (for example, the implant of Medtronic products can only load 40 ml of liquid medicine at most), which can reduce the inconvenience caused by the frequent drug addition of current products, and the drug delivery method is also more flexible, which can not only achieve the purpose of continuous drug delivery, but also can be designed for intermittent drug delivery at a predetermined time.

[0037] At the same time, the present invention adopts a magnetic positioning method, and the movement times of the double-conical magnetic valve can objectively and real-time monitor the drug capacity in the drug bag and the drug administration situation. This is different from the method of fully implanted products on the market that only calculates the remaining drug amount by the set speed and drug administration time, which increases the safety and accuracy of treatment.

[0038] At the same time, the design of the present invention is simple and durable, without too many gear rollers and other linkage mechanical devices to reduce non-medical accidents such as mechanical structure wear or failure after implantation in the human body, which requires skin incision for replacement or repair. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic diagram of the structure of the implantable drug delivery device provided by the present invention when no drug is delivered;

[0040] Figure 2 This is a schematic diagram of the structure of the implantable drug delivery device provided by the present invention when delivering drugs;

[0041] Figure 3 It is a schematic diagram of the internal structure of the housing of the present invention;

[0042] Figure 4 Schematic diagram of displacement change of the drug storage capsule;

[0043] Figure 5 Schematic diagram of the change process of the double-cone magnetic valve. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] according to Figure 1and Figure 2 The implantable drug delivery device 100 provided in this embodiment includes a drug storage and infusion component 10 implanted in the body and a control component 20 disposed outside the body.

[0046] The drug storage and infusion assembly 10 comprises a drug storage unit 11, an infusion unit 12 and a pipeline unit 13 connecting the two. The drug storage unit 11 comprises a housing 110, the interior of which is divided into a sealed pressure chamber 111 and a compressible drug storage bag 112, and a magnetic locator 113 arranged on the pressure chamber and the drug storage bag.

[0047] The material requirements for the outer shell 110 are as follows: non-magnetic conductive material but hard and able to withstand pressure and will not deform under the body pressure of 37°C, preferably plastic steel material. A thermal insulation layer is arranged on the inner wall, and the thermal insulation layer is made of rubber or silicone material. Rubber and silicone have good thermal insulation properties and are often used as thermal insulation materials for pipes, equipment, etc., and can resist the influence of high temperature environment on the equipment. In the present invention, the gas-liquid two-phase mixture will generate or absorb heat during the gas-liquid conversion process, and the thermal insulation layer can buffer and prolong the temperature change time to prevent damage to human tissue. In the present invention, the thermal insulation layer material is preferably silicone, which is a conventional medical material and its safety is guaranteed.

[0048] The pressure chamber 111 is sealed and enclosed by the medicine storage unit shell and the compressible medicine storage bag, and is filled with a gas-liquid two-phase mixture. The pressure chamber is filled with a gas-liquid two-phase mixture similar to a refrigerant, which has stable chemical properties and will not react chemically with the medicine bag material and the shell. The gas-liquid two-phase mixture is preferably selected from any one or a mixture of fluorinated alkane, propane, trichloromonofluoromethane, and butane. These substances can be safely converted into gas and liquid states as the external pressure changes within the constant temperature range of the human body at around 37°C.

[0049] Under the condition of 37℃ relative constant temperature in human body, as the pressure environment changes due to the change of volume of medicine bag, the gas part and liquid transform into each other to keep constant air pressure. When the pressure of medicine bag increases (the volume of medicine injected into medicine bag increases and compresses the pressure chamber part), the heat released in the process of gas conversion into liquid should be small and slow, so as not to burn the human body. When the volume of pressure chamber increases (drug liquid in medicine bag decreases slowly during infusion, the volume of medicine bag decreases slowly, and the relative volume of pressure chamber increases), part of liquid is converted into gaseous state, and heat is absorbed slowly from human body, so as not to cause frostbite. Before leaving the factory, gas and liquid substances are sealed in the pressure chamber according to the parameters required for safety and clinical treatment.

[0050] Specifically, according to Figure 4 When the pressure in the drug storage bag increases (the volume of the drug injected into the drug bag increases and compresses the pressure chamber), the gas is converted into liquid to maintain P AThe heat released in the process should be small and slow so as not to burn the human body. When the volume of the pressure chamber increases (the liquid in the medicine bag is compressed and the relative volume of the pressure chamber increases), part of the liquid is converted into gas, P A The required gas and liquid substances are injected into the pressure chamber according to the required pressure before leaving the factory.

[0051] The top of the drug storage bag 112 is fixedly arranged in the pressure chamber. The gas-liquid two-phase material pre-sealed in the pressure chamber will generate a constant pressure, which compresses the elastic drug liquid in the drug storage bag to generate an internal driving pressure of the drug liquid. In the absence of external magnetic force, the internal driving pressure is greater than the pressure of the target organ tissue in the human body. Under the action of the pressure difference, the double-conical magnetic valve is pushed to the bottom drug outlet of the drug delivery chamber to seal it.

[0052] In terms of structure, the drug storage bag 112 is cylindrical, with a smooth bottom, a serrated middle column, and a drug injection port at the top. Memory silicone 112a is fixedly arranged in the drug injection port. The entire drug storage infusion assembly contacts the subcutaneous tissue of the human body through the top part of the memory silicone 112a. The bottom part of the memory silicone is located in the opening of the drug storage bag 112, and the passage pipe seal passes through the pressure chamber 111 and is sealed and connected to the opening of the drug storage bag. The memory silicone is the contact point between the in vivo infusion assembly and the subcutaneous tissue of the patient's skin. As the penetration point of the injection needle, it can be repeatedly punctured through the skin with a special non-destructive puncture needle to inject supplementary liquid medicine through the filling hole by touch, ultrasonic positioning or using a special non-destructive puncture needle tip to touch and feel, so as to ensure continuous use after implantation. When the liquid medicine in the drug storage bag is lower than the preset amount, the injection needle passes through the skin and the memory silicone contact point to filter the liquid medicine through the liquid medicine filter tank and then inject it into the drug storage bag.

[0053] In order to achieve liquid medicine filtration, a puncture indication point is provided at the top of the memory silica gel 112a, a liquid medicine guide tube is provided inside, and a filter groove is provided at the bottom of the liquid medicine guide tube, which is flush with the bottom opening of the memory silica gel or slightly protrudes from the memory silica gel. The puncture indication point is used to guide the needle into the liquid medicine guide tube, and the liquid medicine guide tube plays a certain role in temporarily storing the liquid medicine injected by the needle, and the liquid medicine in the liquid medicine guide tube enters the medicine storage bag after being filtered through the filter groove.

[0054] The constant air pressure generated by the gas-liquid two-phase mixture compresses the drug storage bag upward and generates a constant internal driving pressure required for clinical treatment. In the absence of external magnetic force, the internal driving pressure is greater than the pressure of the target organ in the human body, and the double-conical magnetic valve is moved to the bottom drug outlet of the drug delivery cavity to seal it. The drug storage bag is made of TPE, PP, PE or PVA; these materials are non-toxic to the human body and are hard plastics. They do not generate elastic force themselves and only produce deformation and volume changes under pressure.

[0055] Combination Figure 1 , Figure 2 , Figure 4 , Figure 5 When the drug liquid is slowly injected through the drug filling hole, the volume of the drug storage bag gradually increases, and the pressure generated on the gas-liquid mixed gas in the closed volume space is greater than the critical pressure of the gas-liquid conversion of the substance. Correspondingly, part of the gas will be converted into liquid. As the liquid increases and the gas decreases, the pressure in the pressure chamber returns to a constant critical preset pressure under the condition of compressed space. When the drug liquid in the drug storage bag is slowly given out and the volume gradually decreases, the volume in the pressure chamber increases accordingly, and the pressure generated on the gas-liquid mixed gas in the closed volume space gradually becomes less than the critical pressure of the gas-liquid conversion of the substance P A， Under the constant temperature of about 37℃ in the human body, the liquid part gradually transforms into gas, and the gas pressure returns to the constant critical preset pressure. In short, during the whole process, as the gas-liquid mixed substances in the pressure chamber transform into each other, the change in the gas-liquid ratio can compress the liquid in the elastic drug storage bag to produce a constant liquid driving pressure P that meets the needs of clinical treatment. B , in the absence of external magnetic force, the internal driving pressure P B Greater than the pressure P of target organs in human body C , move the double-conical magnetic valve to the bottom drug outlet of the drug delivery chamber and seal it.

[0056] Sensor 113 is a positioning permanent magnet, there are three of them, which are respectively arranged at the bottom of the medicine storage bag and the inner wall of the top and bottom of the pressure chamber, and are numbered 113a, 113b, and 113c. As the drug administration process progresses, the medicine storage bag is gradually compressed by the air pressure in the pressure chamber, the positions of the positioning permanent magnets 113b and 113c are fixed, and the displacement between the positioning permanent magnets 113a and 113b and 113c changes. The inductive receiver in the in vitro control component receives the three position information in real time. The controller obtains the displacement change of the mobile end of the medicine storage bag according to the change of the magnetic signal of the sensor, and can monitor the compression degree and the remaining amount of medicine in the medicine storage bag according to the displacement change information. When it changes to the preset displacement space, it indicates that the liquid medicine reserve in the medicine storage bag is insufficient and drug filling is required. At the same time, the sensor can also obtain the relative position of the magnetic valve implanted under the skin and the depth from the skin surface according to the positioning signals of the locators 113b and 113c and the relative fixed position relationship between the two permanent magnets and the infusion unit, thereby indicating the best skin application location of the extracorporeal control unit and obtaining the size of the magnetic air gap with the magnetic valve.

[0057] The infusion unit 12 includes a drug delivery chamber 121, the upper half of which is provided with a funnel-shaped baffle 121a, a drug outlet 121b at the bottom, and a double-cone magnetic valve 121c at the middle. The funnel-shaped baffle 121a is wide at the top and narrow at the bottom, and the wide mouth at the top is connected to or integrally formed with the passage pipe of the pipe unit 13; the drug outlet 121b is provided at the bottom, and has the same inner diameter as the bottom outlet of the funnel-shaped baffle 121a, and is connected to the drug release pipe of the pipe unit.

[0058] The center of the double-cone magnetic valve 121c is a magnetic material, and the outside is wrapped with a non-magnetic and chemically stable coating that does not react with the liquid medicine. The material is selected from silicone or polyethylene. The maximum width of the double-cone magnetic valve is larger than the inner diameter of the medicine outlet of the funnel-shaped baffle and the bottom medicine outlet. At the same time, the distance between the medicine outlet of the funnel-shaped baffle and the bottom medicine outlet is about 1.5 times the length of the double-cone magnetic valve, ensuring that the double-cone magnetic valve can only move between the two medicine outlets, and ensure that the two medicine outlets are not blocked at the same time, and do not react with the liquid medicine.

[0059] In the present invention, the precise minimum dosage can be achieved by controlling the number of cycles of the magnetic valve movement. The manufacturer can control the dosage more precisely and accurately by designing the diameter of the drug inlet and outlet, the speed of the electromagnetic force, etc., to reach or exceed the precise dosage of 48 microliters per day in foreign countries. At present, the minimum daily dosage of most analgesic pumps in China is about 1.2 ml. Clinicians can dilute the drug and inject it into the drug storage bag according to the minimum controllable precision of the product's drug volume and the daily dosage required for treatment, and set the drug administration program in the control module to achieve the treatment purpose (it can be designed into various modes such as intermittent drug administration or continuous drug administration at a specified time every day).

[0060] The pipeline unit 13 includes a passage pipeline 131 connecting the drug storage bag and the drug delivery cavity and a drug release pipeline 132 connecting the bottom drug outlet and the target organ. One end of the passage pipeline 131 seals through the pressure chamber 111 and is sealed and connected to the opening of the drug storage bag 112, and the other end is connected to the upper wide opening portion of the funnel-shaped baffle 121a.

[0061] Combination Figure 1 and Figure 3 The control component 20 includes a housing 21, a power supply 22, a magnetic force generator 23, a controller 24 and an inductive receiver 25 wirelessly connected to the sensor.

[0062] The left and right ends of the housing 21 are provided with fixing belts 211, and the surface is provided with switches 212, display screens 213, injection amount setting keys 214, medicine storage indicator lights 215, and power indicator lights 216. The fixing belt 211 is preferably a shoulder strap or a waist belt to improve the fixing stability; the switch 212 is used to open the control component before medication to achieve wireless communication connection between the components inside and outside the body; the display screen 213 scrolls to display the injection time, set injection amount, and injected amount when the device is working, and displays the battery power when the device is not working; the injection amount setting key 214 is used to set the medication amount. After the setting is completed, the switch device is turned on to start working. The single injection amount is set remotely in advance by the doctor. When the patient uses it, press the button to directly display the amount set in advance, and the patient cannot adjust it by himself; the medicine storage indicator light 215 displays the amount of medicine stored in the medicine storage bag. When the liquid medicine in the medicine storage bag reaches the preset residual amount, the light color changes, prompting the patient to go to the hospital for refilling; the power indicator light 216 prompts the battery power. When the power is insufficient, the color changes, prompting the patient to replace the battery or charge.

[0063] The power source 22 is a common or rechargeable lithium battery or a power supply coil; the magnetic force generator 23 is a common structure in the prior art, including an electromagnet and a coil; the controller 24 is a microprocessor, and the induction receiver 25 is a wireless receiver. These structures are integrated to form a loop.

[0064] The working process and principle of the device of the present invention are as follows:

[0065] Combination Figure 1 , Figure 2 and Figure 5 In the present invention, the driving force for the flow of the drug solution comes from the critical constant pressure P maintained by the gas-liquid phase substance in the closed pressure chamber at 37 degrees Celsius human body temperature that can be mutually transformed with the change of the pressure chamber volume. A , the constant gas pressure P in the pressure chamber of the drug storage bag A The P is always maintained constant under the action of B pressure, generating a constant driving pressure P in the liquid B . In the absence of magnetic force, Figure 1 , pressure P B Greater than the pressure of the target organ in the human body C When the drug outlet at the bottom of the drug delivery chamber is opened, at the pressure P B -P C Driven by the pressure difference, the drug solution is injected into the drug release pipeline.

[0066] After setting the injection amount, the switch is turned on. When the microprocessor 24 is turned on according to the preset program, the power supply and the magnetic force generator are connected. After the magnetic force generator is powered on, the current gradually increases from small to large to generate magnetic force. The magnetic flux acts on the double-conical magnetic valve 121c through the non-magnetic air gaps such as the skin liquid and the implant device shell. As the current increases, the magnetic flux increases, and the electromagnetic force F generated gradually increases to a level greater than the liquid in the drug storage bag to generate the driving pressure P in the liquid. B , driving the double-conical magnetic valve to move upward to block the drug outlet of the funnel-shaped baffle 121a, and the drug solution flows into the drug release pipeline through the released liquid outlet 121b at the bottom of the drug delivery cavity.

[0067] according to Figure 5 The displacement of the double-cone magnetic valve 121c under the action of magnetic force will inevitably cut the magnetic lines and generate induced current which is sensed by the in vitro sensor. When the magnetic valve moves to the upper medicine outlet and stops moving, the in vitro sensor can sense that the magnetic valve moves to the upper medicine outlet through the cessation of the change of magnetic flux and induced current. The logic circuit cuts off the electromagnet current and the corresponding magnetic force disappears. The magnetic valve is at (P B -P C ) driven by pressure difference to return to the lower drug outlet to complete a drug delivery cycle. Only when the upper and lower drug outlets are open at the same time during the short period of time when the magnetic valve moves up and down can the drug delivery be completed under constant pressure drive. Manufacturers can accurately control the size of the individualized electromagnetic force required for re-correction after implantation under the human skin and design each drug delivery cycle to achieve microliter-level precision capacity. Clinicians can adjust the concentration of the drug solution and the frequency, cycle and time of drug delivery according to treatment needs to achieve the treatment purpose.

[0068] In the present invention, the induction receiver not only senses changes in magnetic flux, current, etc., but can also expand and install remote control functions in accordance with relevant medical safety regulations, remotely transmit medication information to the doctor, and remotely control medication dosage and speed adjustment.

[0069] The preferred embodiments of the present invention have been specifically described above, but the present invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. An implantable drug delivery device, characterized in that: It includes a drug storage and infusion component implanted in the body and a control component set outside the body. The drug storage and infusion assembly comprises a drug storage unit, an infusion unit and a pipeline unit; The drug storage unit comprises an outer shell, the interior of which is divided into a sealed pressure chamber and a compressible drug storage bag; the outer shell is made of an inert material that is non-magnetic and has stable physical and chemical properties in the body, and a temperature insulation layer is arranged on the inner wall; the pressure chamber is filled with a gas-liquid two-phase mixture, the drug storage bag is made of compressible rubber or hard plastic, the main body is pleated in design, and a drug filling hole is arranged on the top to repeatedly puncture and inject the drug solution into the drug storage bag; the pressure chamber and the drug storage bag are provided with a magnetic locator; The infusion unit comprises a drug delivery cavity, wherein the upper part of the drug delivery cavity is provided with a funnel-shaped baffle, the bottom end is provided with a drug outlet, and the middle part is provided with a double-cone magnetic valve, the maximum width of the double-cone magnetic valve is greater than the inner diameter of the drug outlet of the funnel-shaped baffle and the bottom end drug outlet, and the two drug outlets are not blocked at the same time, and the magnetic valve can only move up and down between the two drug outlets; The pipeline unit includes a passage pipeline connecting the drug storage bag and the drug delivery cavity and a drug release pipeline connecting the bottom drug outlet and the target organ; The control assembly includes a shell, a power supply, a magnetic force generator, a controller, and an inductive receiver wirelessly connected to the sensor.

2. The implantable drug delivery device according to claim 1, characterized in that: in, The shell is made of plastic steel, and the insulation layer is made of rubber or silicone; The gas-liquid two-phase mixture filled in the pressure chamber is selected from any one of fluorinated alkane, propane, trichlorofluoromethane, butane or a mixture thereof; under the condition of 37°C in the human body, as the volume of the drug storage bag changes causing the pressure environment to change, the gas part and the liquid of the gas-liquid two-phase mixture transform into each other, thereby always maintaining a constant gas pressure as the drug storage bag drug delivery power.

3. The implantable drug delivery device according to claim 1, characterized in that: in, In the drug storage unit, memory silica gel is fixedly arranged in the drug filling hole, the drug storage infusion component contacts the tissue under the human skin through the top part of the memory silica gel, and the bottom part is located in the opening of the drug storage bag, and the passage pipe seal passes through the pressure chamber and is sealed and connected to the opening of the drug storage bag; The top of the memory silicone is provided with a puncture indication point, which can be accurately inserted by touch, ultrasonic positioning or using a special non-destructive puncture needle tip to touch and feel. A liquid medicine guide tube is provided inside, and a filter tank is provided at the bottom end of the liquid medicine guide tube. The filter tank is flush with the bottom opening of the memory silicone or slightly protrudes from the memory silicone.

4. The implantable drug delivery device according to claim 2, Features: in, The medicine storage bag is made of TPE, PP, PE or PVA; The medicine storage bag is cylindrical, with a smooth bottom end, a middle cylindrical bag body that can be folded and compressed along the axial surface, a folded surface that is serrated, a medicine injection port at the top end, and is fixedly arranged in the pressure chamber; The constant air pressure generated by the gas-liquid two-phase mixture compresses the drug storage bag and generates a constant internal driving pressure that meets the requirements of clinical treatment. In the absence of external magnetic force, the internal driving pressure is greater than the pressure of the target organs in the human body, moving the double-conical magnetic valve to the bottom drug outlet of the drug delivery cavity and sealing it.

5. The implantable drug delivery device according to claim 1, Features: in, The sensors are permanent magnets, three in total, which are respectively arranged at the bottom of the medicine storage bag, the top of the pressure chamber and the inner wall of the bottom. The inductive receiver receives the three position information in real time, and the controller monitors the compression degree of the medicine storage bag according to the displacement change of the top of the medicine storage bag obtained by the relative change of the magnetic signal of the sensor; At the same time, the position of the implanted sensor and its subcutaneous distance are obtained according to the relative relationship between the positioning permanent magnets, and then the optimal position for the corresponding application of the control component to the skin on the body surface is obtained.

6. The implantable drug delivery device according to claim 1, characterized in that: in, The center of the double-cone magnetic valve is a magnetic material, and the outside is wrapped with a non-magnetic coating that is chemically stable and does not react with the liquid medicine. The distance between the medicine outlet of the funnel-shaped baffle and the bottom medicine outlet ensures that the magnetic valve can only move up and down between the two medicine outlets.

7. The implantable drug delivery device according to claim 1, characterized in that: in, In the in vitro control component, a fixing belt, a switch, a display screen, an injection volume setting key and a power indicator light are arranged on the shell, the power source is a common or rechargeable lithium battery or a power supply circuit, the magnetic generator includes an electromagnet, the controller is a microprocessor, and the induction receiver is a wireless receiver.

8. The implantable drug delivery device according to claim 7, characterized in that: in, When the microprocessor is started according to the preset program, the power supply and the magnetic generator are turned on. After the magnetic generator is powered on, the current gradually generates magnetic force from small to large, and its magnetic flux acts on the double-cone magnetic valve. As the current increases, the magnetic flux increases, and the electromagnetic force generated gradually increases to a driving pressure greater than the drug liquid in the drug storage bag to generate the drug liquid, driving the double-cone magnetic valve to move up to block the drug outlet of the funnel-shaped baffle. The movement of the double-cone magnetic valve causes the magnetic flux in the air gap between the magnetic generator and the double-cone magnetic valve to change, and is sensed by the induction receiver and transmitted to the microprocessor. After judging that the magnetic valve moves to the drug outlet, the current of the electromagnet coil is cut off, and the magnetic valve begins to move to the lower drug outlet again under the action of the pressure difference and seals again to complete a drug administration cycle; only during the short time when the magnetic valve moves up and down, the upper and lower drug outlets are connected to complete the drug administration under constant pressure drive.

9. The implantable drug delivery device according to claim 7, characterized in that: in, The precision capacity of a drug administration cycle is controlled at the microliter level by designing the size of the electromagnetic force and the diameters of the upper and lower drug outlets.

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