Medical Injection Force Sensor

Abstract

The present invention relates to a medical injection force sensor, comprising: a support body; a pressure sensing module installed on the support body, the pressure sensing module is provided with a conical boss for sensing the pressure on the syringe piston and a plurality of strain gauges spaced around the conical boss, the conical boss applies force to the surroundings when sensing the pressure and drives the plurality of strain gauges to deform; an electrical signal processing module connected to the plurality of strain gauges, the electrical signal processing module converts the resistance increment generated by the deformation into a voltage signal output when the plurality of strain gauges are deformed. The present invention has a simple structure, small space occupation, high reliability, high precision, long service life, is not limited by the force application angle in traditional technology when sensing pressure, can automatically sense the injection pressure of the syringe in real time during the injection process, greatly reduces labor costs and reduces medical risks.

Description

Technical Field

[0001] The invention relates to the technical field of medical injection, and in particular to a medical injection force sensor. Background Art

[0002] The current method of drug injection with a medical syringe pump is: usually a motor is used to drive the screw to rotate and drive the nut forward or backward to realize the movement of the syringe piston, thereby completing the injection or aspiration. It can also be called a constant speed pump or a constant volume pump. The high injection accuracy of this type of pump is controlled by mechanical and electronic precision, and is completely unaffected by the resistance of the syringe and pipeline. In other words, regardless of whether the pressure in the front-end pipeline fluctuates or whether the friction resistance of the syringe piston changes, the syringe pump will complete the injection at the set speed. However, in this way, it is completely unclear about the situation of the syringe piston or the human drug injection pipeline. It is only a simple mechanical movement, and it is impossible to achieve closed-loop monitoring and early warning of the pipeline situation, which endangers personal safety. At present, in order to reduce the risk of injection, manpower must be arranged to check the injection situation in real time, which increases labor costs and has poor reliability. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a medical injection force sensor, which can automatically sense the injection pressure of the syringe in real time during the injection process, greatly reducing labor costs and lowering medical risks.

[0004] The present invention is implemented by the following scheme: A medical injection force sensor, comprising:

[0005] Support body;

[0006] A pressure sensing module installed on the support body, the pressure sensing module is provided with a conical boss for sensing the pressure of the syringe piston and a plurality of strain gauges spaced around the conical boss, the conical boss applies force to the surroundings and drives the plurality of strain gauges to deform when sensing the pressure;

[0007] An electrical signal processing module connected to the plurality of strain gauges converts the resistance increment caused by the deformation into a voltage signal for output when the plurality of strain gauges are deformed.

[0008] During the compressed movement of the piston, the present invention senses the change in pressure (i.e., the change in resistance of the piston pipeline) through the conical boss, and drives the surrounding strain gauges to deform by applying force to the surrounding areas, thereby obtaining a resistance increment, and then converts the resistance increment into a voltage signal output corresponding to the changed pressure through an electrical signal processing module, thereby realizing the monitoring of the entire process state of drug injection and the protection of personnel safety, greatly reducing labor costs and medical risks. At the same time, the force sensor has a simple structure, occupies a small space, has high reliability, high precision, and a long service life, and the conical boss design ensures that the force sensor will not be limited by the force application angle in traditional technologies when sensing pressure.

[0009] A further improvement of the medical injection force sensor of the present invention is that the support body is cylindrical, the pressure sensing module is embedded in the first barrel opening of the support body, and the conical boss protrudes from the support body.

[0010] A further improvement of the medical injection force sensor of the present invention is that the pressure sensing module is disc-shaped, and protrudes into the disc at the middle and edge to form a first protrusion and a second protrusion respectively, the middle of the first protrusion further protrudes into the disc to form the conical boss, a plurality of strain gauges are arranged on the bottom of the disc and the bottom of the disc is embedded in the support body, and the second protrusion blocks and is fixed to the edge of the first barrel mouth.

[0011] A further improvement of the medical injection force sensor of the present invention is that a plurality of riveted columns are fixed at intervals along the circumferential direction on the edge of the first barrel mouth, and a plurality of riveted holes for riveting the plurality of riveted columns are provided on the second protruding portion.

[0012] A further improvement of the medical injection force sensor of the present invention is that when the rivet posts are riveted to the corresponding rivet holes, the conical boss protrudes from the plane where the ends of the plurality of rivet posts are located.

[0013] A further improvement of the medical injection force sensor of the present invention is that a positioning section is provided on the outer peripheral surface of the support body, and the outer contour of the second protrusion is the same as the outer peripheral contour of the support body.

[0014] A further improvement of the medical injection force sensor of the present invention is that the electrical signal processing module is an annular circuit board, and the edge of the annular circuit board is fixed to the inner wall of the support body.

[0015] A further improvement of the medical injection force sensor of the present invention is that the electrical signal processing module is connected to a signal output connection module, and the signal output connection module includes a wire and a plug for docking with an external user interface, one end of the wire is connected to the output end of the electrical signal processing module, and the other end of the wire extends out of the support body and is connected to the plug.

[0016] A further improvement of the medical injection force sensor of the present invention is that a protective cover is provided at the second barrel opening of the support body, and a wire groove for the wire to extend out is provided on the protective cover.

[0017] A further improvement of the medical injection force sensor of the present invention is that a positioning piece protruding inward is provided at the second barrel mouth of the support body, a first positioning recess matched with the positioning piece is provided at a position opposite to the output end of the electrical signal processing module, and a second positioning recess matched with the positioning piece is provided at a position opposite to the wire groove of the protective cover. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The overall structural front view of the force sensor of the present invention is shown.

[0019] Figure 2 A schematic diagram of the three-dimensional structure of the support body of the present invention is shown.

[0020] Figure 3 A schematic diagram of the main structure of the pressure sensing module of the present invention is shown.

[0021] Figure 4 Shows Figure 3 AA side section view.

[0022] Figure 5 The schematic diagram of the Wheatstone bridge of the present invention is shown.

[0023] Figure 6 A three-dimensional structural schematic diagram of the electrical signal processing module of the present invention is shown.

[0024] Figure 7 A three-dimensional structural schematic diagram of the protective cover of the present invention is shown.

[0025] Figure 8 A three-dimensional structural schematic diagram of the signal output connection module of the present invention is shown.

[0026] Fig. 9 A top view of the overall structure of the force sensor of the present invention is shown.

[0027] Fig.10 A schematic diagram of an embodiment of the force sensor of the present invention is shown. DETAILED DESCRIPTION

[0028] In order to solve the problem that traditional pump syringes cannot monitor pipeline conditions and have high injection risks, the present invention provides a medical injection force sensor that can automatically sense the injection pressure of the syringe in real time during the injection process, greatly reducing labor costs and lowering medical risks.

[0029] The medical injection force sensor is further described below with reference to the accompanying drawings.

[0030] See also Figure 1 and Figure 3 As shown, a medical injection force sensor comprises:

[0031] Support body 10;

[0032] A pressure sensing module 20 mounted on the support 10, the pressure sensing module 20 is provided with a conical boss 21 for sensing the pressure of the syringe piston and a plurality of strain gauges 22 spaced around the conical boss 21. When the conical boss 21 senses the pressure, it applies force to the surroundings and drives the plurality of strain gauges 22 to deform.

[0033] The electrical signal processing module connected to the plurality of strain gauges 22 converts the resistance increment generated by the deformation into a voltage signal for output when the plurality of strain gauges 22 are deformed.

[0034] Specifically, when the force sensor is in use, it is installed between the pressure end and the pressure-applying end of the piston, so that the pressure applied by the pressure-applying end is transmitted to the pressure end of the piston through the force sensor, and the resistance generated in the injection tube is also transmitted to the pressure-applying end through the force sensor. In other words, the force sensor can fully sense the applied pressure and the resistance of the injection tube. In order to ensure that the conical boss 21 can accurately sense the pressure of various angles that the syringe piston may be subjected to, when in use, the conical boss 21 is pushed to the middle position of the pressure end of the piston to ensure that the conical boss 21 will not be limited by the force application angle in traditional technology when sensing the pressure of the piston pressure end. Furthermore, in order to make the voltage signal output by the force sensor closer to the actual pressure condition of the syringe piston, it is preferred that the number of the strain gauges 22 is four, and the four strain gauges 22 are arranged at equal intervals with the conical boss 21 as the center, and the four strain gauges 22 are connected to the electrical signal processing module through metal wires to form a Wheatstone bridge, in conjunction with Figure 5 As shown, +ΔR and -ΔR represent the resistance increment of each strain gauge 22. ASIC is an electrical signal processing module in the form of an integrated chip or circuit board. The electrical signal processing module has functions such as calculation, compensation and amplification. The resistance increment of each strain gauge 22 is processed to obtain a voltage signal corresponding to the pressure and output it to facilitate external users to collect and further process data. The specific circuit and working principle of the electrical signal processing module are all existing technologies and will not be repeated here.

[0035] As a preferred embodiment, Figure 2 As shown, the support body 10 is cylindrical, the pressure sensing module 20 is embedded in the first tube opening of the support body 10 , and the conical boss 21 protrudes from the support body 10 .

[0036] Specifically, it is preferred that the diameter of the support body 10 is compatible with the piston diameter of the syringe, and the conical boss 21 is located at the center of the support body 10, so that when in use, the support body 10 is installed at the pressure end of the piston to ensure that the protruding part of the conical boss 21 is against the middle of the pressure end of the piston, thereby ensuring that when the piston moves under pressure, the conical boss 21 can accurately sense the pressure at various angles and transmit the pressure to the strain gauges 22 in all directions.

[0037] As a preferred embodiment, Figure 2 , Figure 3 and Figure 4 As shown, the pressure sensing module 20 is disc-shaped, and protrudes into the disc at the middle and edge to form a first protrusion and a second protrusion respectively. The middle of the first protrusion further protrudes into the disc to form the conical boss 21. A plurality of strain gauges 22 are arranged on the bottom of the disc and the bottom of the disc is embedded in the support body 10. The second protrusion blocks and is fixed to the edge of the first barrel mouth.

[0038] As a preferred embodiment, Figure 2 As shown, a plurality of riveted columns 11 are fixed at intervals along the annular direction on the edge of the first barrel, and a plurality of riveted holes 23 are provided on the second protrusion for riveting the plurality of riveted columns 11. The riveted connection facilitates the disassembly and assembly of the pressure sensing module 20 and the support body 10, and is convenient for maintenance and replacement.

[0039] Furthermore, when the riveting column 11 is riveted to the corresponding riveting hole 23, the conical boss 21 protrudes from the plane where the ends of the riveting columns 11 are located. Figure 1 As shown, to ensure that when the force sensor is in use, the conical boss 21 can press against the pressure-bearing end of the piston and provide a certain deformation space for the conical boss 21.

[0040] As a preferred embodiment, Figure 2 and Figure 3 As shown, the outer peripheral surface of the support body 10 is provided with a positioning cut surface 12 , and the outer contour of the second protrusion is the same as the outer peripheral contour of the support body 10 .

[0041] When embedding the pressure sensing module 20 , the pressure sensing module 20 and the support body 10 can be aligned and installed, which is convenient for positioning the pressure sensing module 20 and can achieve rapid assembly of the two.

[0042] As a preferred embodiment, see Figure 6As shown, the electrical signal processing module is a ring-shaped circuit board, and the edge of the ring-shaped circuit board is bonded and fixed to the inner wall of the support body 10. By installing the electrical signal processing module inside the support body 10, on the one hand, space is saved, and on the other hand, the support body 10 can provide a certain degree of protection for the electrical signal processing module.

[0043] As a preferred embodiment, Figure 8 and Fig. 9 As shown, the electrical signal processing module is connected to a signal output connection module 50, which includes a wire 51 and a plug 52 for docking with an external user interface. One end of the wire 51 is connected to the output end 31 of the electrical signal processing module, and the other end of the wire 51 extends out of the support body 10 and is connected to the plug 52.

[0044] Specifically, the wire 51 is welded to the electrical signal processing module, and the plug 52 is riveted to the wire 51 through one end of the plug terminal and the other end is plugged and connected to the external user interface, so that the operation is convenient and reliable.

[0045] As a preferred embodiment, Figure 7 As shown, a protective cover 40 is provided at the second tube opening of the support body 10 , and a wire groove 41 is provided on the protective cover 40 for the wire 51 to extend out.

[0046] Specifically, the protective cover 40 is fixed to the support body 10 by gluing, and the protective cover 40 insulates and fixes the wire 51 at the wire groove 41 to ensure that the wire 51 is not affected by the complex external environment and is reliable.

[0047] As a preferred embodiment, Figure 2 , Figure 6 and Figure 7 As shown, a positioning member 13 protruding inward is provided at the second tube mouth of the support body 10, a first positioning notch 32 adapted to the positioning member 13 is provided at a position opposite to the output end 31 of the electrical signal processing module, and a second positioning notch 42 adapted to the positioning member 11 is provided at a position opposite to the wire groove 41 of the protective cover 40. The above positioning arrangement facilitates accurate positioning and installation of various parts of the force sensor.

[0048] The present invention can be used for both common syringes and automatic syringes. For common syringes, the pressure-applying end can be a manual pressure-applying device, and for automatic syringes, the pressure-applying end can be an electric pressure-applying device, such as Fig.10As shown, the syringe of this embodiment is an automatic syringe 60, and a driving device 70 for driving the piston movement is provided at the pressure end of the piston. The driving device 70 includes a bracket and a motor-driven screw. The bracket is installed at the pressure end of the piston of the syringe 60. The support body 10 is fixedly installed on the bracket and the conical boss 21 is pressed against the pressure end of the piston. The moving end of the motor-driven screw is fixed to the bracket. The motor-driven screw is connected to the external user interface 80, and the external user interface 80 is also connected to the output end of the electrical signal processing module. The external user interface 80 is pre-set with injection parameters and alarm thresholds. Its working principle is: the external user interface 80 controls the motor-driven screw to drive the piston of the syringe to move according to the injection parameters (including the set speed, etc.). During the movement of the piston, the force sensor senses the pressure change and outputs a voltage signal corresponding to the pressure to the external user interface 80. The external user interface 80 compares the voltage signal with the alarm threshold to determine the force condition of the piston (i.e., the resistance condition in the tube), and adjusts the injection parameters or issues an alarm according to the force condition of the piston. By cooperating with the force sensor and the automatic injector 60, closed-loop control of the entire injection process can be achieved.

[0049] The present invention is described in detail above in conjunction with the embodiments of the accompanying drawings. A person skilled in the art can make various variations of the present invention according to the above description. Therefore, certain details in the embodiments should not constitute a limitation of the present invention, and the scope of protection of the present invention shall be defined by the scope of the attached claims.

Claims

1. A medical injection force sensor, characterized in that: include: Support body; A pressure sensing module installed on the support body, the pressure sensing module is provided with a conical boss for sensing the pressure of the syringe piston and a plurality of strain gauges spaced around the conical boss, the conical boss applies force to the surroundings and drives the plurality of strain gauges to deform when sensing the pressure; an electrical signal processing module connected to the plurality of strain gauges, wherein when the plurality of strain gauges are deformed, the electrical signal processing module converts the resistance increment generated by the deformation into a voltage signal for output; The support body is cylindrical, the pressure sensing module is embedded in the first tube opening of the support body, and the conical boss protrudes from the support body; The pressure sensing module is disc-shaped, and protrudes into the disc at the middle and edge to form a first protrusion and a second protrusion respectively, the middle of the first protrusion further protrudes into the disc to form the conical boss, a plurality of strain gauges are arranged on the bottom of the disc and the bottom of the disc is embedded in the support body, and the second protrusion blocks and is fixed to the edge of the first barrel mouth; The electrical signal processing module is a ring-shaped circuit board, and the edge of the ring-shaped circuit board is fixed to the inner wall of the support body.

2. The medical injection force sensor according to claim 1, characterized in that: A plurality of riveting posts are fixed at intervals along the circumferential direction on the edge of the first barrel mouth, and a plurality of riveting holes for riveting the plurality of riveting posts are respectively provided on the second protruding portion.

3. The medical injection force sensor according to claim 2, characterized in that: When the rivet posts are riveted to the corresponding rivet holes, the conical bosses protrude from the plane where the ends of the plurality of rivet posts are located.

4. The medical injection force sensor according to claim 1, characterized in that: The outer peripheral surface of the support body is provided with a positioning cut surface, and the outer contour of the second protrusion is the same as the outer peripheral contour of the support body.

5. The medical injection force sensor according to claim 1, characterized in that: The electrical signal processing module is connected to a signal output connection module, which includes a wire and a plug for docking with an external user interface. One end of the wire is connected to the output end of the electrical signal processing module, and the other end of the wire extends out of the support body and is connected to the plug.

6. The medical injection force sensor according to claim 5, characterized in that: A protective cover is provided at the second barrel opening of the support body, and a wire groove for the wire to extend out is provided on the protective cover.

7. The medical injection force sensor according to claim 6, characterized in that: A positioning piece protruding inward is provided at the second barrel mouth of the support body, a first positioning recess adapted to the positioning piece is provided at a position opposite to the output end of the electrical signal processing module, and a second positioning recess adapted to the positioning piece is provided at a position opposite to the wire groove of the protective cover.

Images