Flexible wearable muscle relaxation monitoring device

Abstract

The utility model provides a flexible wearable muscle relaxation monitoring device which comprises a flexible wearing device, a sensing control module and a fixator, the flexible wearing device is worn on the hand of a subject in a sleeved mode, the sensing control module is arranged at the position, corresponding to the hallux adductor, of the flexible wearing device, and the fixator limits the sensing control module. The sensing control module provides constant pressure for the hallux adductor and monitors piezoelectric and piezoresistive changes of the hallux adductor. According to the utility model, the pressure applying device is used for applying appropriate force stimulation to a tested part, and the piezoelectric sensor and the piezoresistive sensor are used for monitoring the change of the muscle modulus of a subject at different time points, so that the muscle relaxation state of the subject is quantified and evaluated, and a quantitative index can be provided for the muscle relaxation degree of the subject.

Description

Technical Field

[0001] The utility model relates to the field of muscle relaxation monitoring, in particular to a flexible wearable muscle relaxation monitoring device. Background Art

[0002] Muscle relaxation monitoring technology is a technology used to continuously monitor in real time the changes in the degree of muscle relaxation of patients under general anesthesia or under ventilator support. Muscle relaxation is achieved by skeletal muscle relaxants selectively acting on the N2 receptors on the motor nerve end plate membrane, blocking the transmission of nerve impulses to skeletal muscles, leading to muscle relaxation. This technology is often used during general anesthesia, ICU mechanical ventilation or other processes to prevent patients from experiencing harmful stimuli such as body movement, muscle spasms, choking, and ventilator-machine confrontation, providing good muscle relaxation conditions for endotracheal intubation, mechanical ventilation, microsurgery, and control of muscle spasms.

[0003] Existing muscle relaxation monitoring technology usually evaluates the degree and effect of muscle relaxation by measuring the muscle activity or nerve function of the subject after giving nerve stimulation. At present, the commonly used muscle relaxation monitoring technology is the acceleration muscle relaxation monitor, which determines the muscle relaxation state by measuring the muscle nerve excitability of the subject. Traditional nerve electrical stimulation is by placing electrodes on the skin of the motor nerve (such as radial nerve) that controls the corresponding muscle (such as adductor pollicis), and the electrodes are connected to the acceleration muscle relaxation monitor, and the acceleration sensor is bound to the adductor pollicis, and the forearm is fixed. When the muscle relaxation monitor is started to give different modes of electrical stimulation to the motor nerve, muscle contraction is triggered, and the acceleration change of the muscle is measured by the acceleration sensor and the corresponding data is output, thereby evaluating the degree of muscle relaxation. However, the current monitoring equipment usually needs to fix the tested part of the subject (usually forearm and hand), which is inconvenient to operate and is often interfered and restricted by the complex monitoring environment. The test results will be affected by the operator's operating technique, resulting in inaccurate results. Incorrect electrode position may cause signal interference and inability to accurately measure changes in muscle movement. Different testers often have different interpretations of the test results due to subjective differences in experience, professional knowledge, etc., which may lead to incorrect assessment and management decisions of muscle relaxation status. Therefore, this method requires certain technical knowledge and professional training.

[0004] In addition, electrode placement and electrical stimulation may cause discomfort or skin damage to the subject, and excessive monitoring or frequent stimulation may cause fatigue or discomfort, inaccurate monitoring results. Therefore, existing technologies are not conducive to long-term monitoring. In complex clinical scenarios, electrical stimulation may also interfere with other equipment and electrical equipment (such as electrocardiograms, other electronic medical equipment, etc.), affecting the normal use of other equipment and posing safety issues. Utility Model Content

[0005] In order to overcome the problems in the prior art, the utility model provides an automatically controllable flexible wearable muscle relaxation monitoring device. Without the need for electrical stimulation, piezoelectric / piezoresistive sensors are integrated into a flexible wearable device, thereby realizing continuous, real-time, and long-term monitoring of changes in muscle modulus for different populations.

[0006] The utility model provides the following technical solutions:

[0007] A flexible wearable muscle relaxation monitoring device comprises a flexible wearable device, a sensor control module and a fixator. The flexible wearable device is worn on a subject's hand. The sensor control module is arranged at a position on the flexible wearable device corresponding to the adductor pollicis muscle. The fixator limits the sensor control module. The sensor control module provides dynamic pressure to the adductor pollicis muscle to monitor the piezoelectric and piezoresistance changes of the adductor pollicis muscle.

[0008] Furthermore, the flexible wearable device is a flexible wearable glove, the flexible material is rubber, latex, silicone, nitrile, or elastic fabric, the fixer is a cross-shaped elastic strip with holes at both ends, the strip material is elastic nylon or silicone, and is fixed to the flexible glove with a magnetic buckle.

[0009] Furthermore, the sensor control module is controlled by a single-chip microcomputer to control the on and off of the solenoid valve and the switch of the piezoelectric pump. The piezoelectric pump, the solenoid valve, the pressurizing device, and the air pressure sensor are connected through a four-way pipe to form an air circuit. The solenoid valve controls the on and off of the gas, and the pressurizing device transmits pressure to the adductor pollicis muscle. A piezoresistive sensor and a piezoelectric sensor are provided on the contact surface between the pressurizing device and the adductor pollicis muscle.

[0010] Furthermore, the pressurizing device includes an outer tube and a piston, wherein the piston is connected to a piston shaft and a piston handle by a rubber plug, and the piston handle protrudes out of the outer tube and contacts the adductor pollicis.

[0011] Furthermore, a piezoresistive sensor is bonded to the piston handle. The piezoresistive sensor consists of a piezoresistive film and a comb-shaped electrode. The piezoresistive film is formed by polydimethylsiloxane doped with carbon nanotubes. The electrode is a silver electrode. The silver electrode is laid flat on the piezoresistive film. The upper and lower adhesive polyethylene terephthalate layers encapsulate the electrode layer and the piezoresistive film together. The pressure changes applied to the adductor pollicis muscle are monitored to obtain the force value F on the adductor pollicis muscle.

[0012] Furthermore, the piezoelectric sensor is in a convex shape and is located above the piston handle, with both ends bent and fitted onto the housing of the sensor control module; the piezoelectric sensor is composed of a piezoelectric film and an elastic substrate, the piezoelectric film is a polyvinylidene fluoride film, the elastic substrate is a polyimide film, the piezoelectric film and the piezoelectric film are adhered and bonded by an imide double-sided adhesive, the deformation of the adductor pollicis muscle under pressure is monitored, and the indentation depth value δ of the muscle is obtained.

[0013] A method for automatically monitoring muscle relaxation using a flexible wearable muscle relaxation monitoring device comprises the following steps:

[0014] Step 1: The air pressure sensor detects the air pressure in the air circuit. When the air pressure is lower than 20-25 kPa, the single chip microcomputer controls the solenoid valve to close the air circuit, turns on the piezoelectric pump, and increases the air pressure in the air circuit. When the air pressure sensor detects that the air pressure is greater than 30-35 kPa, the single chip microcomputer controls to turn off the piezoelectric pump.

[0015] Step 2: The outer cylinder of the pressurizing device is deformed by the air pressure, and the extrusion piston moves, pushing the piston handle to squeeze the adductor pollicis muscle. The single chip microcomputer adjusts the power of the piezoelectric pump to make the pressure of the piston 5-8N and the pressure speed 200-230mm / min;

[0016] Step 3: After the piezoresistive sensor is squeezed by the piston handle, the force value F on the adductor pollicis muscle is obtained and converted by the ADC of the single-chip microcomputer and then stored;

[0017] Step 4: After the piezoelectric sensor is squeezed and deformed by the piston handle, the indentation depth value δ of the muscle is obtained and stored after conversion by the ADC of the microcontroller.

[0018] Furthermore, it also includes step five. After the readings of each sensor in steps two to four are stable, the single chip microcomputer controls the solenoid valve to open the gas path, restore the gas pressure to atmospheric pressure, and repeat the above steps one to four for long-term continuous monitoring.

[0019] By adopting the above technical solution, the utility model has the following beneficial effects:

[0020] 1. The utility model uses a pressure applying device to give appropriate force stimulation to the test part, and uses a piezoelectric sensor and a piezoresistive sensor to monitor the changes in the muscle modulus of the subject at different time points, thereby quantifying and evaluating the muscle relaxation state of the subject, and can be used to provide a quantitative indicator for the muscle relaxation of the subject.

[0021] 2. Traditional muscle relaxation monitoring equipment is large and not integrated. The flexible wearable device of the utility model can fix the monitoring device on the adductor pollicis more comfortably. It is lightweight and unconstrained, and the instrument is suitable for monitoring scenarios such as operating rooms and ICUs. In the utility model, the piezoresistor is used as a force sensor, which can not only test the magnitude of the force applied to the measured position in real time, but also use the magnitude of the piezoresistive sensor output corresponding to the magnitude of the set force as the basis for controlling each component. The utility model can obtain long-term, real-time, sensitive and accurate muscle relaxation modulus data for patients without trauma, pain or risk.

[0022] 3. During the testing process of traditional products, the position of the subject's limbs must be strictly limited, which in most cases will interfere with the normal operation and accurate assessment of muscle relaxation. Different from existing products, the utility model has no clear limit on the subject's body position, is friendly to the surgical environment and patients, is easy to operate, and is easy for the test subject to accept.

[0023] 4. The testing mechanism of the utility model is to apply a fixed force to produce muscle deformation, and then test and feedback the changes in muscle modulus under different states. Different from the principle of traditional testing, it avoids repeated and frequent electrical stimulation in the local area, which is a protection for nerve and muscle tissue. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the structure of the flexible wearable muscle relaxation monitoring device of the utility model;

[0025] Figure 2 This is a schematic diagram of the structure of the sensor control module of the utility model;

[0026] Figure 3 It is a structural schematic diagram of the pressurizing device of the utility model;

[0027] Figure 4 This is a schematic diagram of the output change of the piezoelectric sensor of the utility model.

[0028] Description of symbols

[0029] 1. Flexible wearable device, 2. Fixer, 3. Sensor control module, 4. Magnetic buckle, 5. Piezoelectric sensor, 6. Piezoresistive sensor, 7. Sensor control module housing, 8. Pressurizing device, 9. Solenoid valve, 10. Piezoelectric pump, 11. Four-way pipe, 12. Air pressure sensor, 13. Battery, 14. Single chip microcomputer, 15. Piston handle, 16. Piston shaft, 17. Rubber plug, 18. Outer cylinder. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the structural diagrams and specific embodiments described here are only used to explain the utility model, and are not used to limit the utility model.

[0031] Example 1

[0032] like Figure 1As shown, the utility model provides a flexible wearable muscle relaxation monitoring device, including a flexible wearable device 1, a sensor control module 3 and a fixator 2. The flexible wearable device is worn on the subject's hand, and the sensor control module is set on the flexible wearable device at a position corresponding to the adductor pollicis muscle. The fixator limits the sensor control module, and the sensor control module provides dynamic pressure to the adductor pollicis muscle to monitor the changes in pressure and muscle deformation of the adductor pollicis muscle, thereby reflecting the changes in muscle modulus. The calculation of muscle modulus is based on the elastic theory model, that is, the muscle has linear elastic behavior within a small deformation range, and the muscle modulus can be approximately calculated by Hooke's law:

[0033]

[0034] Where E represents the modulus of the muscle, v represents the Poisson's ratio of the muscle. Since the volume change of the muscle is small when compressed, 0.5 is taken as an approximate value. F is the force applied to the muscle, and the magnitude of F can be calculated from the output of the piezoresistive sensor; a is the radius of the piston handle in the pressurizing device, and δ is the indentation depth of the muscle, and its magnitude can be calculated from the output of the piezoelectric sensor. Based on this model, the pressure and indentation depth can be calculated by obtaining the real-time output of the piezoresistance and piezoelectric sensors of the monitoring device, thereby evaluating the real-time modulus change of the muscle.

[0035] The flexible wearable device is a flexible wearable glove, the flexible material is rubber, latex, silicone, nitrile, or elastic fabric, the fixer is a cross-shaped elastic strip with holes at both ends, the strip material is elastic nylon or silicone, and is fixed to the flexible glove by a magnetic buckle 4. The magnetic male head of the magnetic buckle is sealed in the hole of the elastic strip through silicone, exposing the raised magnetic part, and the female head is sealed on the glove in the same way. The combination of the magnetic male head and the female head can realize the fixing of the elastic strip on the flexible glove.

[0036] Example 2

[0037] like Figure 2 , 3 As shown, the sensing control module is controlled by a single chip microcomputer 14 to control the on / off of the solenoid valve 9 and the switch of the piezoelectric pump 10. The piezoelectric pump, the solenoid valve, the pressurizing device 8, and the air pressure sensor 12 are connected through a four-way pipe 11 to form an air circuit. The solenoid valve controls the on / off of the gas, and the pressurizing device transmits pressure to the adductor pollicis muscle. A piezoresistive sensor and a piezoelectric sensor are provided on the contact surface between the pressurizing device and the adductor pollicis muscle.

[0038] The pressurizing device comprises an outer tube 18 and a piston. The piston is connected to a piston shaft 16 and a piston handle 15 by a rubber stopper 17. The piston handle protrudes out of the outer tube and contacts the adductor pollicis.

[0039] The piezoresistive sensor is fitted and connected to the piston handle. The piezoresistive sensor consists of a piezoresistive film and a comb-shaped electrode. The piezoresistive film is made of polydimethylsiloxane (PDMS) doped with carbon nanotubes (CNT). The electrode is a silver electrode, which is laid flat on the piezoresistive film. The upper and lower layers of sticky polyethylene terephthalate (PET) encapsulate the electrode layer and the piezoresistive film together.

[0040] When the piezoresistive sensor is squeezed by the piston handle, the porosity of the piezoresistive film changes, causing the overall resistance to change. When the battery is at a constant voltage, the output current changes and changes with the force. The greater the pressure, the smaller the resistance and the greater the current. The pressure change applied to the adductor pollicis muscle is monitored to obtain the force value F on the adductor pollicis muscle.

[0041] The piezoelectric sensor is convex and located above the piston handle, with its two ends bent and fitted on the housing of the sensor control module. The piezoelectric sensor consists of a piezoelectric film and an elastic substrate. The piezoelectric film is a polyvinylidene fluoride (PVDF) film, and the elastic substrate is a polyimide (PI) film. The piezoelectric film and the piezoelectric film are bonded together by imide double-sided tape to monitor the deformation of the adductor pollicis muscle under pressure and obtain the indentation depth value δ of the muscle.

[0042] After the piezoelectric sensor is deformed by the piston handle, it is polarized in the thickness direction and a potential difference is generated between the upper and lower surfaces. The magnitude of the potential difference is positively correlated with the strain of the film at the same pressure speed, that is, the greater the strain, the greater the potential difference. The deformation of the adductor pollicis muscle under pressure is monitored to obtain the indentation depth value δ of the muscle. The value E of the muscle modulus can be approximated by calculating the force value F of the adductor pollicis muscle and the indentation depth value δ through formula (1).

[0043] The piezoelectric sensor and the piezoresistive sensor monitor the changes in the subject's muscle modulus at different time points, thereby quantifying and evaluating the subject's muscle relaxation state, which can be used to provide a quantitative indicator of the subject's muscle relaxation.

[0044] Example 3

[0045] A method for automatically monitoring muscle relaxation using a flexible wearable muscle relaxation monitoring device comprises the following steps:

[0046] Step 1: The air pressure sensor detects the air pressure in the air circuit. When the air pressure is lower than 20-25 kPa, the single chip microcomputer controls the solenoid valve to close the air circuit, turns on the piezoelectric pump, and increases the air pressure in the air circuit. When the air pressure sensor detects that the air pressure is greater than 30-35 kPa, the single chip microcomputer controls to turn off the piezoelectric pump.

[0047] Step 2: The outer cylinder of the pressurizing device is deformed by the air pressure, and the extrusion piston moves, pushing the piston handle to squeeze the adductor pollicis muscle. The single chip microcomputer adjusts the power of the piezoelectric pump to make the pressure of the piston 5-8N and the pressure speed 200-230mm / min;

[0048] Step 3: After the piezoresistive sensor is squeezed by the piston handle, the force value F on the adductor pollicis muscle is obtained and converted by the ADC of the single-chip microcomputer and then stored;

[0049] Step 4: After the piezoelectric sensor is squeezed and deformed by the piston handle, the indentation depth value δ of the muscle is obtained and stored after conversion by the ADC of the microcontroller.

[0050] Preferably, the method further includes step 5, in which after the readings of the sensors in steps 2 to 4 are stabilized, the single chip microcomputer controls the solenoid valve to open the gas path, restores the gas pressure to atmospheric pressure, and repeats the above steps 1 to 4 for long-term continuous monitoring.

[0051] The reliability of the monitoring device of the utility model is verified through in vitro skin model testing experiments.

[0052] Silicone with different hardness was used to simulate skin with different moduli. Ecoflex series silicone was used to configure silicone with hardness of <0, 0, 5, 10, 15, 20, 25, and 30. A MARK-10 dynamometer was used to apply a constant pressure (F=5N) to the silicone to be tested at a speed of 300mm / min to test the output change of the piezoelectric sensor of the muscle relaxation monitoring device of the utility model. The results of the piezoelectric output of the same force applied by silicone with different hardness are shown in the figure. Figure 4 shown.

[0053] The results show that when the same force acts on silicone with different hardness, as the hardness of the silicone increases, the silicone deformation becomes smaller and the output of the piezoelectric sensor becomes smaller, thereby proving the feasibility of the device of the utility model.

[0054] The above-mentioned embodiments only express the implementation methods of the utility model, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent of the utility model. It should be pointed out that, for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, and these all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A flexible wearable muscle relaxation monitoring device, comprising a flexible wearable device, a sensor control module and a fixator, characterized in that: The flexible wearable device is worn on the hand of the subject, the sensor control module is arranged on the flexible wearable device at a position corresponding to the adductor pollicis muscle, the sensor control module is limited by a fixer, and the sensor control module provides dynamic pressure to the adductor pollicis muscle to monitor the piezoelectric and piezoresistance changes of the adductor pollicis muscle.

2. The flexible wearable muscle relaxation monitoring device according to claim 1, characterized in that: The flexible wearable device is a flexible wearable glove, the flexible material is rubber, latex, silicone, nitrile, or elastic fabric, the fixer is a cross-shaped elastic strip with holes at both ends, the strip material is elastic nylon or silicone, and is fixed to the flexible glove with a magnetic buckle.

3. The flexible wearable muscle relaxation monitoring device according to claim 1, characterized in that: The sensing control module is controlled by a single-chip microcomputer to control the on and off of the solenoid valve and the switch of the piezoelectric pump. The piezoelectric pump, the solenoid valve, the pressurizing device, and the air pressure sensor are connected through a four-way pipe to form an air circuit. The solenoid valve controls the on and off of the gas. The pressurizing device transmits pressure to the adductor pollicis muscle. A piezoresistive sensor and a piezoelectric sensor are provided on the contact surface between the pressurizing device and the adductor pollicis muscle.

4. The flexible wearable muscle relaxation monitoring device according to claim 3, characterized in that: The pressurizing device comprises an outer tube and a piston. The piston is connected to a piston shaft and a piston handle by a rubber plug. The piston handle protrudes out of the outer tube and contacts the adductor pollicis.

5. The flexible wearable muscle relaxation monitoring device according to claim 3, characterized in that: The piezoresistive sensor is fitted and connected to the piston handle. The piezoresistive sensor consists of a piezoresistive film and a comb-shaped electrode. The piezoresistive film is made of polydimethylsiloxane doped with carbon nanotubes, and the electrode is a silver electrode. The silver electrode is laid flat on the piezoresistive film. The upper and lower layers of sticky polyethylene terephthalate layers encapsulate the electrode layer and the piezoresistive film together to monitor the pressure changes applied to the adductor pollicis muscle and obtain the force value F on the adductor pollicis muscle.

6. The flexible wearable muscle relaxation monitoring device according to claim 3, characterized in that: The piezoelectric sensor is convex and located above the piston handle, with its two ends bent and fitted on the housing of the sensor control module. The piezoelectric sensor consists of a piezoelectric film and an elastic substrate. The piezoelectric film is a polyvinylidene fluoride film, and the elastic substrate is a polyimide film. The piezoelectric film and the piezoelectric film are bonded together by imide double-sided tape to monitor the deformation of the adductor pollicis muscle under pressure and obtain the indentation depth value δ of the muscle.

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