JP2008229313A - Injection needle puncturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an injection needle puncturing device which can be made compact and whose cost is reduced and which can detect puncture of a needle point into a blood vessel with high sensitivity, while preventing wasteful use of liquid chemicals. <P>SOLUTION: The injection needle puncturing device includes: a liquid storage part 10; an injection needle 20 placed on one end side of the liquid storage part 10 to be punctured into a living body; a force detecting part 30 to detect force applied to the injection needle 20 from outside; a piston part 40 in the liquid storage part 10; a movement part 50 to move the piston part 40 along the longitudinal direction of the liquid storage part 10; and a movement control part 60 to stop the movement part 50 on the basis of the fact that the magnitude of detected force reaches a predetermined value after moving the movement part 50 in a direction the injection needle 20 is punctured. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a needle insertion device for inserting a needle into a blood vessel of a vein.

  Tail vein injection technology for small animals is not only used in life science, pharmacy, basic medicine, and clinical medicine research fields, but also in vivo screening at the drug discovery stage, pharmacokinetics and safety tests at the preclinical stage, etc.・ Food, chemistry, medical equipment, clinical testing, and other technologies used daily by various companies.

  However, this technique is a skilled person technique that requires skill, and it takes a lot of time to learn. Particularly difficult is accurate position recognition of the tail vein. If the position cannot be recognized, a situation occurs in which the injection needle penetrates the blood vessel or the injection needle does not pierce the blood vessel.

  Conventionally, position recognition of tail vein blood vessels has been based on a sense cultivated through experience. Specifically, the change of the pressure applied by the injection needle tip by the insertion operation of the injection needle is determined by directly capturing the change with the hand. This is not limited to the tail vein, but is a blood vessel position recognition method common to drug administration and blood collection operations using an injection needle from a vein. Recently, it is desired to develop an automated technique for the position recognition method.

The prior art describes a blood collection device, particularly a technique for automatically searching for blood vessels. In this device, it has been proposed to incorporate a pressure detection device that detects whether or not the blood collection needle accurately punctures a blood vessel based on a pressure change in the blood collection needle (for example, Patent Document 1).
JP-A-4-338458

  Theoretically, blood collection and drug solution administration are the reverse procedures, and thus it is considered possible to apply the above-described conventional device to drug solution administration, but this has the following problems.

  First of all, in this apparatus, in addition to the vacuum pump for negative pressure inside the injection needle and inside the apparatus for collecting blood, a pressure for detecting the pressure inside the injection needle is provided around the injection needle. A detection device must be provided, and there is a problem that the entire device becomes large.

  In addition, when administering a drug solution, not only the drug solution is filled inside the injection needle, but also a connection tube that connects the injection needle and the pressure detection device, and also a connection tube that connects the injection needle and the vacuum pump. It is necessary to fill the chemical. Therefore, a large amount of chemical solution must be prepared, and it is difficult to administer an accurate amount of the chemical solution.

  Furthermore, in order to prevent contamination of the specimen, in order to replace the injection needle, not only the injection needle but also the connecting tube connected to the injection needle must be replaced. The cost of was high.

  In addition, in order to detect a pressure change with high sensitivity, it is necessary to reduce the internal volume of the space (injection needle, pressure detection device, and a pipe or tube connecting them) that is a pressure measurement target. However, if the internal volume of the pressure measurement space is extremely small, the pressure fluctuates due to disturbance such as slight air leaks, resulting in high noise, making it impossible to detect stable pressure changes.

  Therefore, the present invention has been made to solve the above-described problems. The needle tip is inserted into the blood vessel while reducing the size and cost of the apparatus and avoiding waste of the chemical solution. An object of the present invention is to provide an injection needle insertion device that can detect this with high sensitivity.

  In order to achieve the above object, an apparatus of the present invention includes a liquid storage part, an injection needle disposed on one end side of the liquid storage part and inserted into a living body, and force detection for detecting a force applied to the injection needle. A moving portion that moves the piston portion along a length direction of the liquid storage portion, and a direction in which the injection needle is inserted. And an operation control unit that stops the moving unit based on the fact that the magnitude of the detected force reaches a predetermined value after the movement.

  In the needle insertion device according to the present invention, there is no need to make the inside of the injection needle and the inside of the device negative pressure, so there is no need to provide a vacuum pump for making the negative pressure, and the whole device is made smaller than before. be able to. In addition, since there is no need to provide a vacuum pump, it is not necessary to inject a chemical into the connecting pipe that connects the vacuum pump and the liquid container, and the amount of chemical to be prepared can be minimized, and an accurate amount of You can administer medicinal solution. Furthermore, since there is no connection pipe connected to the liquid storage part, for example, a connection pipe connecting the vacuum pump and the liquid storage part, the disposable part is reduced as compared with the conventional case, and the cost can be reduced. Further, in order to detect whether or not the injection needle has been inserted into the living body, the pressure applied to the force detection unit itself is detected, not the pressure fluctuation in the liquid storage unit. For this reason, it is possible to detect with high accuracy whether or not the injection needle has been inserted into the living body without being influenced by the pressure fluctuation caused by the air leaking from the liquid container.

  That is, according to the present invention, it is possible to detect with high sensitivity that the needle tip has been inserted into the blood vessel while reducing the size and cost of the apparatus and not wasting the chemical solution.

  The force detection unit of the injection needle insertion device according to the present invention is disposed on the needle surface of the injection needle and the other end opposite to the one end inserted into the living body or the surface of the liquid storage unit. As a result, when the injection needle is inserted, the force detection unit is arranged at the portion (the other end portion) where the displacement is greatest in the injection needle, so the force detection unit more reliably detects the displacement of the injection needle. can do.

  The force detection unit of the present invention has a hollow part into which the injection needle or the liquid storage part is press-fitted, and is detachable from the injection needle or the liquid storage part. Thereby, when discarding a liquid storage part etc., since a force detection part can be removed from the other end part of an injection needle or the said liquid storage part, a force detection part can be used effectively.

  The force detection unit of the present invention includes at least two micro displacement detection units, and the operation control unit is based on the fact that any of the forces detected by the micro displacement detection unit has reached a predetermined value. Stop the moving part.

  In the operation control unit of the needle insertion device according to the present invention, the moving unit is stopped based on the fact that the total value of the forces detected by each of the minute displacement detection units has reached a predetermined value. According to the present invention, by using two or more minute displacement detection units, it is possible to detect displacement more accurately and reliably without depending on only one displacement detection result.

  The apparatus of the present invention includes a liquid container, an injection needle that is disposed on one end side of the liquid container and is inserted into a living body, a force detector that detects an external force applied to the injection needle, and the liquid After moving the moving part in the direction in which the injection needle is inserted, the moving part that moves the piston part along the length direction of the liquid containing part, and the piston part provided in the containing part And an operation control unit that stops the moving unit based on detection of a temporal change in the magnitude of the detected force.

  In the operation control unit of the needle insertion device according to the present invention, after the detected magnitude of the force reaches a first predetermined value, a predetermined value based on a second predetermined value lower than the first predetermined value is used. When the force continues for a predetermined period in the allowable range, the piston part is stopped via the moving part.

  In the injection needle insertion device according to the present invention, the moving unit is stopped based on the fact that the temporal change in the detected force is present at a predetermined stage. According to the present invention, the pressure change applied to the injection needle is mainly in (1) the stage before being inserted into the skin, (2) the stage inserted into the skin, and (3) the stage inserted into the blood vessel. Therefore, it is possible to reliably specify the movement until the injection needle is inserted into the blood vessel, so that it is possible to detect with high sensitivity that the needle tip has been inserted into the blood vessel.

  The present invention can provide an injection needle insertion device that can detect with high sensitivity that a needle tip has been inserted into a blood vessel. This technique can prevent leakage at the time of administration of a drug solution into a blood vessel or leakage at the time of blood collection, and at the same time, can realize downsizing and cost reduction with respect to a conventional device.

BEST MODE FOR CARRYING OUT THE INVENTION

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a basic configuration of a needle insertion device 1 according to the present invention. An injection needle insertion device 1 according to the present invention detects a liquid storage unit 10, an injection needle 20 that is disposed on one end side of the liquid storage unit 10 and is inserted into a living body, and a force applied to the injection needle 20 from the outside. In the direction in which the injection needle 20 is inserted, the force detection unit 30 that performs, the piston unit 40 provided in the liquid storage unit, the moving unit 50 that moves the piston unit 40 along the longitudinal direction of the liquid storage unit 10 After the moving unit 50 is moved, the operation control unit 60 is configured to stop the moving unit 50 based on the fact that the magnitude of the detected force has reached a predetermined value (Pe shown in FIG. 6). In addition, after the movement control part 60 moved the moving part 50 to the direction in which the injection needle 20 is inserted, the time change of the magnitude | size of the detected force was detected (for example, Pb shown in FIG. 6). -Pc ', Pc'-Pc, Pc-Pd, Pd-Pe), the moving unit 50 may be stopped.

(First embodiment)
As a first embodiment, a series of operations when injecting PBS into the venous blood vessel of the tail of an 8-week-old Balb / c mouse by the apparatus of the present invention in order to perform a control experiment when conducting a drug administration experiment Is described.

  First, the configuration of the needle insertion device 1 will be described in detail. The injection needle 20 is made of stainless steel, has a thickness of 22-27G, and has an inner wall that is anticoagulated with an anticoagulant such as heparin. The liquid container 10 uses a plastic syringe 201 containing PBS inside. A pressure sensor 102 is used as a detection element of the force detection unit 30.

  The pressure sensor 102 is detachable with respect to the injection needle 20 or the syringe 201. For example, as shown in FIGS. 2A and 2B, the pressure sensor 102 is connected to the injection needle 20 via the needle base 101. Or as shown in FIG.2 (c), it connects directly with the syringe 201 connected with the injection needle 20. FIG. As shown in FIG. 9, the pressure sensor 102 is connected after the injection needle 20 and the syringe 201 are connected, and is configured to be detached from the injection needle 20 and the syringe 201 after a series of drug solution administration operations is completed. The above-described operations related to attachment / detachment are preferably performed in an aseptic space in order to prevent contamination of the specimen via the pressure sensor 102.

  Next, the configuration of a signal transmission path between each element will be described with reference to FIG. 3, and the operation of the apparatus will be described with reference to a flow chart 5 showing an operation of drug solution administration.

  First, the output signal of the pressure sensor 102 is sent to the operation control unit 60 through the first wiring 301. The operation control unit 60 includes a force detection unit 306, a calculation unit 307, a piston control unit 308, and an XYZ stage control unit 309. Based on the output signal of the pressure sensor 102, the actuator 203 and the XY stage. The operation of 207, the Z stage 208, and the Z stage 209 is controlled.

  A signal sent from the XYZ stage control unit 309 in the operation control unit 60 is transmitted to the XY stage 207 that controls the relative position between the support base 206 and the substrate 210, and the Z stage 208 and the Z stage 209. Thus, the position and angle of the support 206 with respect to the substrate 210 are changed, and the incident angle of the injection needle 20 with respect to the skin and blood vessels is controlled. The support platform 206 has a joint 204 and a joint 205 thereon. The joint 204 supports the syringe 201 and the piston part 40 in which PBS is housed, and the joint 205 supports the actuator 203 that controls the operation of the piston part 40.

  The actuator 203, the joint 204, the joint 205, the support base 206, the XY stage 207, and the Z stages 208 and 209 constitute a moving unit.

  In the present invention, it is most important to monitor the pressure change applied to the injection needle 20 and determine the venous blood vessel position, so this part will be described in detail.

  First, the 8-week-old Balb / c mouse is fixed with its legs down, and the thickness of the tail is measured in advance. This information is used in step S7 to set as a limit distance that the injection needle 20 can move within the tail. Here, the limit distance is set to the radius of the tail section at the insertion position of the injection needle 20, and the information is given in advance to the calculation unit 307 of the operation control unit 60.

  In order to administer PBS to the tail vein, the injection needle 20 starts to advance (step S1). After the apparatus is started, the output signal of the pressure sensor 102 is constantly sent to the force detection unit 306 and measured (step S2). At this time, since the experiment so far has confirmed that the position of the injection needle 20 and the pressure applied to the injection needle 20 are as shown in FIG. 4, these pieces of information are stored in advance in the calculation unit 307 as known information. Give it. Therefore, the information input from the force detection unit 306 to the calculation unit 307 and the information of the position of the XY stage 207 input from the XYZ stage control unit 309 to the calculation unit 307 are compared with each other. Thus, the position of the tip of the injection needle 20 in the living body can be accurately controlled.

  The injection needle 20 is moved by the XY stage 207 until the signal in the force detection unit 306 changes discontinuously from Pc ′ to Pc (first predetermined value). This pressure change applied to the injection needle 20 is generated when the skin of the mouse tail is inserted. Next, the injection needle 20 moves in the subcutaneous tissue of the mouse tail by the XY stage 207. The pressure measured by the force detection unit 306 in this section shows a constant rate of change from Pc to Pd. Eventually, a location (second predetermined value) where the pressure measured by the force detection unit 306 changes discontinuously from Pd to Pe is detected (step S3). In the predetermined permissible range based on the second predetermined value, when the measured pressure continues for a predetermined period, it is determined in the calculation unit 307 that the injection needle 20 has crossed the venous blood vessel wall. A signal to be stopped is sent from the calculation unit 307 to the XY stage 207 via the XYZ stage control unit 309, and the movement of the injection needle 20 is stopped (step S4). The predetermined allowable range is preferably within a range of ± 5% with respect to the second predetermined value.

  At this position, the chemical solution administration operation is started (step S5). First, in the calculation unit 307, information on a preset dose is converted into an operation amount of the piston unit 40, and the signal is sent to the piston control unit 308. The signal sent to the piston control unit 308 controls the operation of the piston unit 40 in the longitudinal direction via the actuator 203, and controls the dose for injecting the drug solution in the syringe 201 into the venous blood vessel. When it is determined that the administration of the preset dose has been completed based on the signal sent from the piston control unit 308 to the calculation unit 307 (step S6), the calculation unit 307 notifies the XYZ stage control unit 309. A signal is given, and the XY stage 207 is retracted to the initial position (step S11). In this way, a series of steps for injecting PBS into the venous blood vessel of the tail of an 8-week-old Balb / c mouse is completed.

  However, when the injection needle 20 is moved in the subcutaneous tissue of the mouse tail by the XY stage 207 in the above-described process, the calculation unit 307 performs the XY stage 207 via the XYZ stage control unit 309. The signal input from the force detection unit 306 to the calculation unit 307 continues to exhibit a constant rate of change from Pc to Pd even after the limit distance to which the injection needle 20 can move within the tail is given to In some cases, a discontinuous pressure change (second predetermined value) from Pd to Pe is not detected. This indicates that the blood vessel is not captured by a minute error in the vicinity of the venous blood vessel. In this case, the calculation unit 307 determines whether or not the injection needle 20 has moved to the limit distance (step S7).

  When the limit has not yet been reached, the signal from the calculation unit 307 moves the XY stage 207 to the initial position via the XYZ stage control unit 309 in order to withdraw the injection needle 20 from the mouse tail. . Then, a series of operations are performed in which the injection needle 20 is moved by the XY stage 207 until the signal in the force detection unit 306 changes discontinuously from Pc ′ to Pc. If the limit distance is reached, the injection needle 20 is retracted to the initial position by the XY stage 207 (step S8), and the incident angle θ of the injection needle 20 with respect to the skin and blood vessels, that is, the injection needle 20 is installed. An angle θ formed between the support 206 and the substrate 210 is adjusted. Specifically, the operation unit 307 is contracted to the Z stage 208 via the XYZ stage control unit 309, and the Z stage 209 is extended to increase the angle θ to a preset value (step S9). . At this time, if the angle θ is smaller than the limit θmax, the movement of the XY stage 207 is started from the calculation unit 307 via the XYZ stage control unit 309 (step S10). Then, a series of operations in which the injection needle 20 is moved by the XY stage 207 is performed again until the signal is discontinuously changed from Pc ′ to Pc in the force detection unit 306. If the angle θ is larger than the limit θmax, the calculation unit 307 determines to stop the chemical solution administration operation, and moves the XY stage 207 back to the initial position via the XYZ stage control unit 309 to thereby store the chemical solution. The administration operation is terminated (step S11).

  In the injection needle insertion device 1 according to the present invention, it is not necessary to make the negative pressure inside the injection needle 20 and the inside of the device, so it is not necessary to provide a vacuum pump for making the negative pressure, and the entire device is smaller than the conventional device. Can be In addition, since there is no need to provide a vacuum pump, it is not necessary to inject a chemical into the connecting pipe that connects the vacuum pump and the liquid container, and the amount of the chemical to be prepared can be minimized, and an accurate amount can be obtained. You can administer a drug solution. Furthermore, since there is no connecting pipe connected to the syringe 201, for example, a connecting pipe that connects the vacuum pump and the liquid storage portion, the number of disposable parts is smaller than in the conventional case, and the cost can be reduced. Further, in order to detect whether or not the injection needle 20 has been inserted into the living body, the pressure applied to the pressure sensor 102 itself is detected, not the pressure fluctuation in the syringe 201. For this reason, it is possible to detect with high accuracy whether or not the injection needle 20 has been inserted into the living body without being influenced by the pressure fluctuation caused by the air leaking from the syringe 201.

  That is, according to the present invention, it is possible to detect with high sensitivity that the needle tip has been inserted into the blood vessel while reducing the size and cost of the apparatus and not wasting the chemical solution.

  In addition, when the injection needle 20 is inserted, the pressure sensor 102 is disposed at a portion (the other end portion) where the displacement is the largest in the injection needle 20, so that the pressure sensor 102 more reliably displaces the injection needle 20. Can be detected. Furthermore, since the pressure sensor can be removed from the other end of the injection needle 20 when the syringe 201 or the like is discarded, the pressure sensor 102 can be used effectively.

  In the injection needle insertion device 1 according to the present invention, the moving unit is stopped based on the fact that the detected temporal change in the force exists at a predetermined stage. According to the present invention, the pressure change applied to the injection needle 20 is mainly in the stage (1) before being inserted into the skin, (2) the stage where it is inserted into the skin, and (3) the stage where it is inserted into the blood vessel. Since the movement until the injection needle 20 is inserted into the blood vessel can be reliably identified, it is possible to detect with high sensitivity that the needle tip has been inserted into the blood vessel.

  The application of the device of the present invention according to the present embodiment may be not only for drug solution administration but also for blood collection. At that time, blood is collected as the pressurizing operation by the piston portion 40 in step S5, on the contrary, by the pulling operation by pulling the piston portion 40. Accordingly, in step S6, the completion of blood collection is determined.

  Moreover, according to this embodiment, the usage target of the needle insertion device is not limited to animals, but may be humans.

(Second embodiment)
As a second embodiment, a series of operations when injecting PBS into the venous blood vessel of the tail of an 8-week-old Balb / c mouse by the apparatus of the present invention in order to perform a control experiment when conducting a drug administration experiment Is described.

  First, the configuration of the apparatus will be described in detail. The injection needle 20 is made of stainless steel, has a thickness of 22-27G, and has an inner wall that is anticoagulated with an anticoagulant such as heparin. The liquid container 10 uses a plastic syringe 201 containing PBS inside. A strain sensor 103 is used as a detection element of the force detection unit 30.

  The strain sensor 103 is connected to the injection needle 20 via the needle base 101 as shown in FIGS. Or as shown in FIG.2 (f), it connects directly with the syringe 201 connected with the injection needle 20. FIG. As shown in FIG. 9, the strain sensor 103 is connected after the injection needle 20 and the syringe 201 are connected, and is detachable from the injection needle 20 and the syringe 201 after a series of chemical solution administration operations is completed. It has become. The above-described operations related to attachment / detachment are performed in a sterile space in order to prevent contamination of the specimen via the strain sensor 103.

  The strain sensor 103 includes two or more micro displacement detectors that can detect a longitudinal force received by the tip of the injection needle 20 as a micro displacement. Specifically, as shown in FIG. 8, the strain sensor 103 includes a minute displacement detector 401, a minute displacement detector 402, a minute displacement detector 403, a minute displacement detector 404, and these four minute displacement detectors are hollow. It takes the structure connected in the shape which divided the in-plane into 4 parts. The strain sensor 103 to which the four minute displacement detection units are connected has a structure capable of detecting the force applied to the injection needle by being press-fitted and brought into close contact with the injection needle 20 or the liquid storage unit 10. The motion control unit 60 stops the moving unit 50 based on the fact that any of the forces detected by the four minute displacement detection units has reached a predetermined position. Alternatively, the moving unit 50 is stopped based on the fact that the sum of the forces detected by the four minute displacement detection units has reached a predetermined position.

  These minute displacement detectors also serve as a noise component detection and removal system for the force applied to the injection needle 20. This noise component removal system will be described with reference to the flowchart of FIG. First, the injection needle 20 starts to advance in order to start administration of the chemical solution (step S201). After starting the apparatus, the force applied to the injection needle 20 is detected by the four minute displacement detectors (step S202), and the force detector 306 calculates an output signal from each minute displacement detector (step S203). Here, the noise component applied to the injection needle 20 is removed by taking the difference between the signals (step S204). After the blood vessel is detected by the calculation result of the output signal (step S205), the injection needle 20 is stopped and the drug solution administration is completed (step S206).

  Next, the configuration of the signal transmission path between each element will be described with reference to FIG.

  First, the output signal of the strain sensor 103 is sent to the operation control unit 60 through the first wiring 301. The motion control unit 60 includes a force detection unit 306, a calculation unit 307, a piston control unit 308, and an XYZ stage control unit 309. Based on the output signal of the strain sensor 103, the actuator 203 and the XY stage. The operation of 207, the Z stage 208, and the Z stage 209 is controlled.

  A signal sent from the XYZ stage control unit 309 in the operation control unit 60 is transmitted to the XY stage 207 that controls the relative position between the support base 206 and the substrate 210, and the Z stage 208 and the Z stage 209. Thus, the position and angle of the support 206 with respect to the substrate 210 are changed, and the incident angle of the injection needle 20 with respect to the skin and blood vessels is controlled. The support platform 206 has a joint 204 and a joint 205 thereon. The joint 204 supports the syringe 201 and the piston part 40 in which PBS is housed, and the joint 205 supports the actuator 203 that controls the operation of the piston part 40.

In the present invention, it is most important to monitor the strain change applied to the injection needle 20 and determine the venous blood vessel position.
First, the 8-week-old Balb / c mouse is fixed with its legs down, and the thickness of the tail is measured in advance. This information is used in step S7 to set as a limit distance that the injection needle 20 can move within the tail. Here, the limit distance is set to the radius of the tail section at the insertion position of the injection needle 20, and the information is given in advance to the calculation unit 307 of the operation control unit 60.

  In order to administer PBS to the tail vein, the injection needle 20 starts to advance (step S101). After the apparatus is started, the output signal of the strain sensor 103 is constantly sent to the force detection unit 306 and measured (step S102). At this time, the position of the injection needle 20 and the strain applied to the injection needle 20 have been confirmed by experiments so far as shown in FIG. 6, and thus these pieces of information are given in advance to the calculation unit 307 as known information. Keep it. Therefore, the information input from the force detection unit 306 to the calculation unit 307 and the information of the position of the XY stage 207 input from the XYZ stage control unit 309 to the calculation unit 307 are compared with each other. Thus, the position of the tip of the injection needle 20 in the living body can be accurately controlled.

  The injection needle 20 is moved by the XY stage 207 until the signal in the force detection unit 306 changes discontinuously from Pc ′ to Pc (first predetermined value). This strain change applied to the injection needle 20 is generated when the skin of the mouse tail is inserted. Next, the injection needle 20 moves in the subcutaneous tissue of the mouse tail by the XY stage 207. The strain measured by the force detection unit 306 in this section shows a constant rate of change from Pc to Pd. Eventually, a location (second predetermined value) where the strain measured by the force detection unit 306 changes discontinuously from Pd to Pe is detected (step S103). When this change continues for a predetermined period, the calculation unit 307 determines that the injection needle 20 has crossed the venous blood vessel wall, and a signal for immediately stopping the injection needle 20 is sent from the calculation unit 307 to the XYZ stage control. It is sent to the XY stage 207 via the unit 309, and the movement of the injection needle 20 is stopped (step S104).

  At this position, the chemical solution administration operation is started (step S105). First, in the calculation unit 307, information on a preset dose is converted into an operation amount of the piston unit 40, and the signal is sent to the piston control unit 308. The signal sent to the piston control unit 308 controls the operation of the piston unit 40 in the longitudinal direction via the actuator 203, and controls the dose for injecting the drug solution in the syringe 201 into the venous blood vessel. When it is determined that the administration of the preset dose has been completed based on the signal sent from the piston control unit 308 to the calculation unit 307 (step S106), the calculation unit 307 notifies the XYZ stage control unit 309. A signal is given, and the XY stage 207 is retracted to the initial position (step S111). In this way, a series of steps for injecting PBS into the venous blood vessel of the tail of an 8-week-old Balb / c mouse is completed.

  However, when the injection needle 20 is moved in the subcutaneous tissue of the mouse tail by the XY stage 207 in the above-described process, the calculation unit 307 performs the XY stage 207 via the XYZ stage control unit 309. The signal input from the force detection unit 306 to the calculation unit 307 continues to exhibit a constant rate of change from Pc to Pd even after the limit distance to which the injection needle 20 can move within the tail is given to In some cases, a discontinuous strain change (second predetermined value) from Pd to Pe is not detected. This indicates that the blood vessel is not captured by a minute error in the vicinity of the venous blood vessel. In this case, the calculation unit 307 determines whether or not the injection needle 20 has moved to the limit distance (step S107).

  When the limit has not yet been reached, the signal from the calculation unit 307 moves the XY stage 207 to the initial position via the XYZ stage control unit 309 in order to withdraw the injection needle 20 from the mouse tail. . Then, a series of operations are performed in which the injection needle 20 is moved by the XY stage 207 until the signal in the force detection unit 306 changes discontinuously from Pc ′ to Pc. If the limit distance is reached, the injection needle 20 is retracted to the initial position by the XY stage 207 (step S108), and the incident angle θ of the injection needle 20 with respect to the skin and blood vessels, that is, the injection needle 20 is installed. An angle θ formed between the support 206 and the substrate 210 is adjusted. Specifically, the operation unit 307 is contracted to the Z stage 208 via the XYZ stage control unit 309, and the Z stage 209 is extended to increase the angle θ to a preset value (step S109). . At this time, if the angle θ is smaller than the limit θmax, the movement of the XY stage 207 is started from the calculation unit 307 via the XYZ stage control unit 309 (step S110). Then, a series of operations in which the injection needle 20 is moved by the XY stage 207 is performed again until the signal is discontinuously changed from Pc ′ to Pc in the force detection unit 306. If the angle θ is larger than the limit θmax, the calculation unit 307 determines to stop the chemical solution administration operation, and moves the XY stage 207 back to the initial position via the XYZ stage control unit 309 to thereby store the chemical solution. The administration operation is terminated (step S111).

  In addition, as an application of this apparatus by this embodiment, not only chemical | medical solution administration but blood collection may be sufficient. In that case, blood is collected as the pressurizing operation by pulling the piston portion 40 in the pressurizing operation by the piston portion 40 in step S105. Accordingly, in step S106, it is determined whether blood collection is complete.

  As described above, according to the present embodiment, the same effects as those of the first embodiment can be obtained while reducing the size and cost of the apparatus.

(Third embodiment)
In 3rd embodiment, the structure of the pressure sensor 102 differs from the structure of 1st embodiment and 2nd embodiment. Hereinafter, the contents common to the configurations of the first embodiment and the second embodiment will be omitted.

  The pressure sensor 102 includes two or more micro displacement detectors that can detect a longitudinal force received by the tip of the injection needle 20 as a micro displacement. Specifically, as shown in FIG. 8, the pressure sensor 102 includes a minute displacement detector 401, a minute displacement detector 402, a minute displacement detector 403, a minute displacement detector 404, and these four minute displacement detectors are hollow. It takes the structure connected in the shape which divided the in-plane into 4 parts. The pressure sensor 102 to which the four minute displacement detection units are connected has a structure capable of detecting the force applied to the injection needle by press-fitting and closely contacting the injection needle 20 or the liquid storage unit 10. The motion control unit 60 stops the moving unit 50 based on the fact that any of the forces detected by the four minute displacement detection units has reached a predetermined position. Alternatively, the moving unit 50 is stopped based on the fact that the sum of the forces detected by the four minute displacement detection units has reached a predetermined position.

  These minute displacement detection units may also serve as a noise component detection / removal system for the force applied to the injection needle 20. This noise component removal system will be described with reference to the flowchart of FIG. First, the injection needle 20 starts to advance in order to start administration of the chemical solution (step S201). After starting the apparatus, the force applied to the injection needle 20 is detected by the four minute displacement detectors (step S202), and the force detector 306 calculates an output signal from each minute displacement detector (step S203). Here, the noise component applied to the injection needle 20 is removed by taking the difference between the signals (step S204). After the blood vessel is detected by the calculation result of the output signal (step S205), the injection needle 20 is stopped and the drug solution administration is completed (step S206).

  In the present embodiment, four micro displacement detectors are provided, but the present invention is not limited to this. Specifically, two minute displacement detectors may be provided. The minute displacement detection unit may be combined with other minute displacement detection units, and it is desirable that an even number of minute displacement detection units be provided.

1 is an overall configuration diagram of a needle insertion device according to the present invention. It is a figure which shows the force detection part which concerns on this invention, and its periphery. It is an internal block diagram of the injection needle insertion apparatus which concerns on this invention. It is a figure which shows the time change of the pressure concerning an injection needle position and an injection needle. It is a flowchart which shows operation | movement of the injection needle insertion apparatus which concerns on this invention. It is a figure which shows the time change of the distortion concerning an injection needle position and an injection needle. It is a flowchart which shows operation | movement of the injection needle insertion apparatus which concerns on this invention. It is a figure which shows that the force detection part which concerns on this invention is comprised from a micro displacement detection part. It is a figure which shows attachment / detachment operation | movement of the force detection part which concerns on this invention. It is a flowchart figure of the noise component removal system by a minute displacement detection part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Liquid storage part 20 Injection needle 30 Force detection part 40 Piston part 50 Movement part 60 Operation control part 101 Needle base 102 Pressure sensor 103 Strain sensor 104 Needle pipe 201 Syringe 202 Joint 203 Actuator 204 Joint 205 Joint 206 Support stand 207 XY stage 208 Z stage 209 Z stage 210 Substrate 301 Wiring 302 Wiring 303 Wiring 304 Wiring 306 Force detection unit 307 Calculation unit 308 Piston control unit 309 XYZ stage control unit 401 Micro displacement detection unit 402 Micro displacement detection unit 403 Micro displacement detection Section 404 Minute displacement detector

Claims (10)

A liquid container;
An injection needle that is disposed on one end side of the liquid container and is inserted into a living body;
A force detector for detecting a force applied to the injection needle;
A piston part provided in the liquid storage part;
A moving part for moving the piston part along the length direction of the liquid container;
An operation control unit that stops the moving unit based on the fact that the magnitude of the detected force reaches a predetermined value after moving the moving unit in a direction in which the injection needle is inserted. A needle insertion device characterized by that. The injection needle has the other end opposite to the one end inserted into the living body,
The injection needle insertion device according to claim 1, wherein the force detection unit is provided at the other end.   The injection needle insertion device according to claim 2, wherein the force detection unit is detachable from the injection needle.   The injection needle insertion device according to claim 1, wherein the force detection unit is provided in the liquid storage unit.   The injection needle insertion device according to claim 4, wherein the force detection unit is detachable from the liquid storage unit.   6. The injection needle insertion device according to claim 3, wherein the force detection unit includes a hollow part into which the injection needle or the liquid storage unit is press-fitted. The force detection unit includes at least two minute displacement detection units,
2. The injection needle stick according to claim 1, wherein the motion control unit stops the moving unit based on a fact that any of the forces detected by the minute displacement detection unit has reached a predetermined value. Input device. The force detection unit includes at least two minute displacement detection units,
2. The injection according to claim 1, wherein the motion control unit stops the moving unit based on a sum of force values detected by the minute displacement detection units reaching a predetermined value. Needle insertion device. A liquid container;
An injection needle disposed on one end side of the liquid container and inserted into a living body;
A force detection unit for detecting a force applied from the outside to the injection needle;
A piston portion provided in the liquid storage portion;
A moving part for moving the piston part along the length direction of the liquid container;
An operation control unit for stopping the moving unit based on detection of a temporal change in the magnitude of the detected force after moving the moving unit in a direction in which the injection needle is inserted; and A needle insertion device characterized by comprising:   The operation control unit continues the force for a predetermined period within a predetermined allowable range based on a second predetermined value lower than the first predetermined value after the detected magnitude of the force reaches a first predetermined value. The injection needle insertion device according to claim 1, wherein when it is, the piston portion is stopped via the moving portion.

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