Muscle contraction rate detection method based on thin film pressure sensor and magnetic field stimulator

Abstract

The present application relates to a muscle contraction rate detection method based on a thin film pressure sensor and a magnetic field stimulation instrument, and belongs to the technical field of medical detection. The muscle contraction rate detection method based on the thin film pressure sensor comprises the following steps: S1) pressure value conversion; S2) self-gravity measurement; S3) resting muscle strength measurement; S4) stimulated muscle strength measurement; and S5) muscle contraction rate calculation. According to the conversion formula of the voltage and resistance of the thin film pressure sensor, the self-gravity of the stimulation coil module, the muscle strength value in the resting state and the muscle strength value in the stimulated state are measured according to factual analysis and theoretical derivation and combined with actual operation. The self-gravity of the stimulation coil module and the muscle strength value in the resting state are creatively analyzed and excluded from the influence on the actual muscle contraction rate, and the detection precision of the muscle contraction rate is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of medical detection, and particularly relates to a muscle contraction rate detection method based on a thin film pressure sensor and a magnetic field stimulator. BACKGROUND

[0002] With the popularization and use of the magnetic field stimulator, more and more magnetic field stimulators are used in pelvic floor treatment and muscle shaping; there is a lack of effective muscle contraction rate detection method. The related use scene does not see the existing literature disclosing the measurement and calculation method of the muscle contraction rate.

[0003] In addition, the current muscle contraction rate measurement method mainly has the following two kinds:

[0004] I. Use the electromyographic device to cooperate, and calculate the muscle contraction rate by detecting the electromyographic signal of the muscle when the magnetic field stimulator works.

[0005] However, the electromyographic device has a disadvantage that it must be attached to the human skin, which makes the detection work troublesome and complex when the magnetic field stimulator is used for treating female pelvic floor and hip shaping, and also causes a considerable part of patients to have resistance and resistance behavior.

[0006] II. Use the air bag to adhere to the muscle, and calculate the muscle contraction rate by detecting the value of the air pressure sensor in the air circuit when the magnetic field stimulator works.

[0007] However, the magnetic field stimulator of this scheme needs to additionally increase the air injection system, so that the system is bloated, and the air bag needs to be attached to the muscle with a strap, and overpressure can easily cause the air bag to be damaged. SUMMARY

[0008] To solve the technical problems of the lack of effective muscle contraction rate detection method in the prior art, and the simple and safe measurement product, the application provides a muscle contraction rate detection method based on a thin film pressure sensor and a magnetic field stimulator.

[0009] The purpose of the application can be achieved by the following technical solutions:

[0010] The muscle contraction rate detection method based on the thin film pressure sensor comprises the following steps:

[0011] S1) Pressure value conversion: Since the thin film pressure sensor is equivalent to a variable resistor, its real-time working resistance will change after being affected by the pressure; the conversion relationship between the real-time working resistance of the thin film pressure sensor and the pressure is:

[0012] ;

[0013] In the formula, R is the real-time working resistance of the thin film pressure sensor; F is the pressure borne by the thin film pressure sensor; and K is a conversion coefficient.

[0014] Preferably, the measurement method of the real-time working resistance of the thin film pressure sensor is as follows:

[0015] In the circuit of the magnetic field stimulator, the real-time working resistance of the thin film pressure sensor is measured and calculated through the operation circuit of the operational amplifier by adopting the resistance voltage division method; and the calculation formula is as follows:

[0016] ;

[0017] In the formula, is a given input voltage; is the working voltage of the thin film pressure sensor, which is measured through the operational amplifier; is the real-time working resistance of the thin film pressure sensor; is a known resistance.

[0018] Preferably, the measurement method of the real-time working resistance of the thin film pressure sensor is to adopt the Wheatstone bridge method, and the specific steps are as follows:

[0019] The thin film pressure sensor is taken as one arm of the bridge, and the other three arms are known resistances.

[0020] The bridge is adjusted to reach a balanced state, at which time the output voltage of the bridge is zero.

[0021] The real-time working resistance of the thin film pressure sensor is calculated through the known resistances and the balanced condition of the bridge.

[0022] Preferably, the specific value of the conversion coefficient is solved and verified through calibration experiments. The conversion coefficient (K) is a key parameter, and a reasonable and matched calibration experiment is formulated according to the actual application scene and measurement data; and the accuracy is verified. This method ensures the reliability and precision of the measurement results.

[0023] S2) Measurement of self-gravity: the pressure value of the thin film pressure sensor under the action of only the gravity of the stimulating coil module, i.e. the self-gravity of the stimulating coil module, is measured; and the calculation formula is expressed as:

[0024] ;

[0025] In the formula, is the self-gravity of the stimulating coil module; is the real-time working resistance of the thin film pressure sensor under the action of only the gravity of the stimulating coil module; and K is a conversion coefficient.

[0026] Preferably, the method of statistical root mean square value is also included to eliminate the measurement error of the self-gravity of the stimulating coil module, and is used as the subsequent calculation standard; the specific method is:

[0027] The self-gravity data set of the stimulating coil module is calculated again The self-gravity data set of the stimulating coil module is calculated again The root mean square value of the self-gravity of the stimulating coil module is calculated

[0028] ;

[0029] In the formula, The root mean square value of the self-gravity of the stimulating coil module is calculated The self-gravity value of the stimulating coil module is calculated The total number of the data set is calculated

[0030] S3) Resting muscle force measurement: the muscle force generated by the muscle when the stimulating coil module is placed on the muscle and not working, at this time the muscle force and the gravity of the stimulating coil module interact, causing the pressure change of the thin film pressure sensor, resulting in that the pressure of the thin film pressure sensor is no longer equal to the self-gravity of the stimulating coil module;

[0031] The real-time working resistance of the thin film pressure sensor at this time is obtained, and the pressure of the thin film pressure sensor at this time is calculated

[0032] ;

[0033] In the formula, The pressure of the thin film pressure sensor in the resting measurement is calculated The real-time working resistance of the thin film pressure sensor in the resting measurement is calculated

[0034] The difference between the self-gravity of the stimulating coil module and the pressure of the thin film pressure sensor in the resting measurement is the resting muscle force; the calculation formula is:

[0035] ;

[0036] In the formula, The resting muscle force is calculated by taking the absolute value of the difference; The pressure of the thin film pressure sensor in the resting measurement is calculated The self-gravity of the stimulating coil module is calculated

[0037] Preferably, the method of statistical root mean square value is also included to eliminate the measurement error of the self-gravity of the stimulating coil module, and is used as the subsequent calculation standard; the specific method is:

[0038] S4) Stimulus muscle strength measurement: when the stimulation coil module is placed on the muscle and works, the muscle will contract isometrically or isotonically with the frequency of the magnetic field stimulation, so that the pressure of the diaphragm pressure sensor changes;

[0039] Obtain the real-time working resistance of the diaphragm pressure sensor in the stimulation measurement, and calculate the pressure of the diaphragm pressure sensor at this time;

[0040]

[0041] In the formula, is the pressure of the diaphragm pressure sensor in the stimulation measurement; is the real-time working resistance of the diaphragm pressure sensor in the stimulation measurement;

[0042] The difference between the self-gravity of the diaphragm pressure sensor and the stimulation measurement pressure is the stimulated muscle strength; its calculation formula is:

[0043]

[0044] In the formula, is the stimulated muscle strength, and the absolute value of the difference is taken; is the pressure of the diaphragm pressure sensor in the stimulation measurement; is the self-gravity of the stimulation coil module.

[0045] Preferably, the statistical root mean square value method is used to eliminate the measurement error of the stimulated muscle strength, and is used as the subsequent calculation standard.

[0046] S5) Muscle contraction rate calculation: the difference between the resting muscle strength and the stimulated muscle strength is used to calculate the muscle contraction rate; its calculation formula is:

[0047]

[0048] In the formula, is the muscle contraction rate; is the stimulated muscle strength; is the resting muscle strength.

[0049] Preferably, the calculation data of the muscle contraction rate is taken as the corresponding root mean square value.

[0050] Preferably, the application also provides a magnetic field stimulation instrument based on a diaphragm pressure sensor, which comprises a diaphragm pressure sensor working circuit and a stimulation coil module; the diaphragm pressure sensor working circuit is used to measure the real-time working resistance of the diaphragm pressure sensor, and comprises a diaphragm pressure sensor, a known resistance and an operational amplifier; the diaphragm pressure sensor is connected to the positive input end of the operational amplifier; the known resistance is respectively connected to the negative input end and the output end of the operational amplifier; and the stimulation coil module is used to generate a high-intensity changing magnetic field and act on the target muscle group. ​​​

[0051] Advantages of the present application:

[0052] 1. The present application is based on the conversion formula of the voltage and resistance of the thin film pressure sensor, and the self-gravity of the stimulating coil module, the muscle strength value in the resting state and the muscle strength value in the stimulating state are measured according to the fact analysis and theoretical derivation, and combined with the actual operation. The influence of the self-gravity of the stimulating coil module and the muscle strength value in the resting state on the actual muscle contraction rate is creatively analyzed and excluded, and the detection accuracy of the muscle contraction rate is improved.

[0053] 2. The working circuit of the thin film pressure sensor is designed by adopting the resistance voltage division method or the Wheatstone bridge method, so as to improve the convenience and accuracy of the real-time resistance measurement of the thin film pressure sensor.

[0054] 3. The present application integrates the magnetic field stimulating instrument of the thin film pressure sensor; unlike the traditional use of air bag and air pressure sensor to measure muscle strength value, it does not need additional air pressure sensor, does not need additional air conveying system, and does not have the risk of air bag pressure burst. Therefore, the scheme based on the thin film pressure sensor is simpler and easier to realize. BRIEF DESCRIPTION OF DRAWINGS

[0055] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed for the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0056] Fig. 1 The method flow chart of the muscle contraction rate detection method based on the thin film pressure sensor of the present application.

[0057] Fig. 2 The structure schematic diagram of the magnetic field stimulating instrument based on the thin film pressure sensor of the present application.

[0058] Fig. 3 The working circuit principle diagram of the thin film pressure sensor in the magnetic field stimulating instrument based on the thin film pressure sensor of the present application. DETAILED DESCRIPTION

[0059] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0060] Please refer to Figs. 1-3As shown, the muscle contraction rate detection method based on the film pressure sensor and the magnetic field stimulation instrument both belong to the protection range of the present application,

[0061] The muscle contraction rate detection method based on the film pressure sensor and the magnetic field stimulation instrument comprise the following steps:

[0062] S1) Pressure value conversion: Since the film pressure sensor is equivalent to a variable resistor, its real-time working resistance will change after being affected by pressure; the conversion relationship between the real-time working resistance of the film pressure sensor and the pressure is:

[0063] ;

[0064] In the formula, R is the real-time working resistance of the film pressure sensor; F is the pressure borne by the film pressure sensor; and K is the conversion coefficient.

[0065] Specifically, the film pressure sensor is a device that converts pressure into resistance change, so it can be equivalent to a variable resistor that changes with pressure; it is composed of sensitive materials such as carbon paste wrapped in PET material. It is suitable for smooth surfaces, with a repetition rate of ±5% and a nonlinear pressure-resistance relationship. Specifically, the relationship between pressure and resistance value generally presents an approximate inverse, rather than a linear relationship.

[0066] It should be noted that the magnetic field stimulation instrument in the present application can be applied to muscle detection and rehabilitation treatment; and the film pressure sensor therein can be used for real-time monitoring of muscle activity. By attaching the sensor to the skin surface, subtle deformation and pressure changes of the muscle under magnetic field stimulation can be detected. These data can be used to evaluate the reactivity and functional status of the muscle, helping doctors and researchers understand the health status of the muscle.

[0067] The stimulation coil module can be used in muscle rehabilitation treatment, by generating a high-intensity varying magnetic field, penetrating fat tissue, and acting on the target muscle group; the magnetic field generates an induced current in the target muscle group, depolarizes the motor neurons, and induces muscle peak contraction. This peak contraction increases the strength and tension of the muscle, and the stimulation coil module is used for non-therapeutic scenarios such as health human muscle strength evaluation and fitness training effect monitoring; the magnetic field strength, frequency, and pulse width output by the magnetic field stimulation instrument of the present application are within the safe range, and are only used for non-therapeutic purposes of health human muscle strength evaluation.

[0068] Therefore, by integrating the film pressure sensor into the magnetic field stimulation instrument, the new magnetic field stimulation instrument can not only be used for muscle rehabilitation treatment, but also can detect and evaluate indicators such as muscle contraction rate and muscle pressure value; it shows its unique advantages and broad application prospects.

[0069] Preferably, the measurement method of the real-time working resistance of the film pressure sensor is:

[0070] In the circuit of the magnetic field stimulator, a resistive voltage divider is used. The operational amplifier circuit measures and calculates the real-time operating resistance of the thin-film pressure sensor; the calculation formula is as follows:

[0071] ;

[0072] In the formula: It is the given input voltage; This is the operating voltage of the thin-film pressure sensor, which is measured using an operational amplifier. It is the real-time operating resistance of the thin-film pressure sensor; The resistance is known.

[0073] Specifically, such as Fig. 1 In the thin-film pressure sensor measurement circuit shown, a voltage divider is used. The real-time operating resistance R of the thin-film pressure sensor and the known resistance R2 form a voltage divider circuit. The thin-film pressure sensor is connected to the positive input terminal of the operational amplifier OPA. The known resistance R2 is shorted to the negative input and output terminals of the OPA, forming a voltage follower. Therefore, the resistance R of the thin-film pressure sensor varies with the pressure magnitude. Furthermore, different models of thin-film pressure sensors (different sizes and materials, etc.) will have different K values.

[0074] In practical implementation, high-performance thin-film pressure sensors manufactured by Changzhou Tianze Electronic Technology Co., Ltd. can be selected. These sensors utilize a gridded semiconductor substrate and contain multiple sensing elements, enabling precise measurement of pressure changes. They are typically used in applications requiring high precision and sensitivity, such as industrial automation and medical equipment.

[0075] Preferably, the method for measuring the real-time operating resistance of the thin-film pressure sensor is the Wheatstone bridge method, and the specific steps are as follows:

[0076] The thin-film pressure sensor is used as one arm of the bridge, and the other three arms are known resistors.

[0077] Adjust the bridge circuit to achieve a balanced state, at which point the output voltage of the bridge circuit is zero.

[0078] The real-time operating resistance of the thin-film pressure sensor is calculated using the known resistance and the balance condition of the bridge circuit.

[0079] In the implementation process, WIKA FLC-1000 series thin film pressure sensor produced by WIKA (Suzhou) Co., Ltd. can also be selected. The grid type resistance structure is adopted, four resistors are integrated inside, and the Wheatstone bridge is installed on the diaphragm; so as to directly calculate the real-time working resistance of the thin film pressure sensor. This design can accurately detect the deformation of the diaphragm under pressure, and is suitable for high-precision pressure measurement.

[0080] Preferably, the specific value of the conversion coefficient is solved and verified by calibration experiment. The conversion coefficient (K) is a key parameter, and a reasonable and matched calibration experiment is formulated according to the actual application scene and measurement data; and the accuracy is verified. This method ensures the reliability and accuracy of the measurement results.

[0081] S2) Self-gravity measurement: measure the pressure value of the thin film pressure sensor under the action of only the gravity of the stimulating coil module, that is, the self-gravity of the stimulating coil module; the calculation formula is represented as:

[0082] ;

[0083] In the formula, is the self-gravity of the stimulating coil module; is the real-time working resistance of the thin film pressure sensor under the action of only the gravity of the stimulating coil module; K is the conversion coefficient.

[0084] Specifically, as shown in Fig. 3 , the thin film pressure sensor is integrated into the magnetic field stimulation instrument for muscle pressure detection. Since the thin film pressure sensor is combined with the stimulating coil module by adhesion or buckling, when the muscle tissue is detected, the thin film pressure sensor bears the gravity from the stimulating coil module. If the muscle contraction rate is to be accurately calculated, the influence of the gravity of the stimulating coil module on the muscle strength needs to be excluded. Therefore, the gravity of the stimulating coil module needs to be measured; the specific measurement process is as follows:

[0085] Firstly, the magnetic field stimulation instrument is placed horizontally on the desktop and powered on, and the thin film pressure sensor can collect data, but the magnetic field stimulation coil does not work;

[0086] Under the action of only the gravity of the stimulating coil module, the real-time working resistance collected by the thin film pressure sensor;

[0087] Through the resistance pressure conversion formula, the pressure value of the thin film pressure sensor is calculated, that is, the self-gravity of the stimulating coil module.

[0088] Preferably, the method of statistical root mean square value is also adopted to eliminate the measurement error of the self-gravity of the stimulating coil module, and is used as the subsequent calculation standard; the specific method is:

[0089] Obtain the data set of the real-time working resistance of the thin film pressure sensor by repeating the self-gravity measurement of step S2) multiple times , and then calculate the self-gravity data set of the stimulating coil module ; and finally calculate the root mean square value thereof

[0090] ;

[0091] In the formula, is the root mean square value of the self-gravity of the stimulating coil module is the self-gravity value of the stimulating coil module is the total number of data sets

[0092] Specifically, during the repeated measurement and sampling process, due to the structural layout and material distribution of the stimulating coil module and the thin film pressure sensor in the main structure of the new magnetic field stimulator, the thin film pressure sensor can more accurately measure the pressure by adjusting different placement attitudes and flattening the surface.

[0093] The root mean square (RMS) is a commonly used statistical indicator for measuring the dispersion degree of a group of data. Its calculation method is to square each data value first, then take the average of these squared values, and finally take the square root of the average. And take it as the subsequent calculation standard, further improve the measurement accuracy and reliability.

[0094] S3) Resting muscle strength measurement: the muscle strength generated by the muscle when the stimulating coil module is placed on the muscle and not working, at this time the muscle strength interacts with the gravity of the stimulating coil module, causing the pressure change of the thin film pressure sensor, resulting in that the pressure of the thin film pressure sensor is no longer equal to the self-gravity of the stimulating coil module

[0095] Obtain the real-time working resistance of the thin film pressure sensor at this time of resting measurement, and calculate the pressure of the thin film pressure sensor at this time

[0096] ;

[0097] In the formula, is the pressure of the thin film pressure sensor in the resting measurement is the real-time working resistance of the thin film pressure sensor in the resting measurement

[0098] The difference between the self-gravity of the stimulating coil module and the pressure of the thin film pressure sensor in the resting measurement is the resting muscle strength; its calculation formula is:

[0099] ;

[0100] In the formula, The absolute value of the difference is the resting muscle strength; The pressure of the thin film pressure sensor in the resting measurement; The self-weight of the stimulation coil module.

[0101] Specifically, before stimulation, the resting muscle strength needs to be measured. This step mainly measures the muscle strength generated by the muscle when the stimulation coil is at rest and acts on the muscle. Generally, the resting muscle strength measurement refers to the muscle strength generated by the muscle when the stimulation coil module is combined with the muscle through its own weight or through the binding belt before the magnetic field stimulator stimulates. At this time, the magnetic field stimulator does not stimulate, but the stimulation coil module actively or passively generates pressure on the muscle, thereby generating the resting muscle strength of the muscle.

[0102] Therefore, the difference between the self-weight of the stimulation coil module and the pressure of the thin film pressure sensor in the resting measurement is the resting muscle strength.

[0103] Preferably, the resting muscle strength is measured by repeating step S3) multiple times, and a statistical root mean square value method is used to eliminate the measurement error of the resting muscle strength and serve as a subsequent calculation standard.

[0104] Specifically, this step can capture the data of pressure changes through high-frequency sampling to ensure the accuracy and integrity of the data. Statistical methods are used to analyze the data and extract accurate parameters such as root mean square.

[0105] In the resting measurement process, a suitable time period is selected, and the real-time working resistance of the thin film pressure sensor is collected at a sampling rate of 60-100 Hz. Then, the pressure of the thin film pressure sensor in the resting measurement is calculated to form a data set. Finally, a statistical root mean square value method is used to eliminate the measurement error of the resting muscle strength and serve as a subsequent calculation standard.

[0106] S4) Stimulation muscle strength measurement: When the stimulation coil module is placed on the muscle and works, the muscle will contract isometrically or isotonically with the frequency of the magnetic field stimulation, causing the pressure of the thin film pressure sensor to change;

[0107] The real-time working resistance of the thin film pressure sensor in the stimulation measurement is obtained, and the pressure of the thin film pressure sensor at this time is calculated;

[0108] ;

[0109] In the formula, The pressure of the thin film pressure sensor in the stimulation measurement; The real-time working resistance of the thin film pressure sensor in the stimulation measurement;

[0110] The difference between the self-weight of the thin film pressure sensor and the stimulation measurement pressure is the stimulation muscle strength; and the calculation formula is:

[0111] ;

[0112] wherein, is the absolute value of the difference; is the pressure of the film pressure sensor in the stimulation measurement; is the self-gravity of the stimulation coil module.

[0113] Preferably, the statistical root mean square value method is used to eliminate the measurement error of the stimulated muscle strength and as the subsequent calculation standard.

[0114] Specifically, the magnetic field stimulator measures the muscle strength generated by the muscle when the stimulation coil module is working. After the stimulation coil starts working, the muscle will contract isometrically or isotonicly with the frequency of the magnetic field stimulation, thereby changing the pressure of the film pressure sensor.

[0115] Similarly, this step can also be captured by high-frequency sampling, capturing the data of pressure changes. During the stimulation measurement, a suitable time period is selected to collect the real-time working resistance of the film pressure sensor at a sampling rate of 60-100 Hz, and a data collection is formed. Finally, the statistical root mean square value method is used to eliminate the measurement error of the resting muscle strength and as the subsequent calculation standard.

[0116] S5) Muscle contraction rate calculation: calculate the muscle contraction rate according to the difference between the resting muscle strength and the stimulated muscle strength; the calculation formula is:

[0117] ;

[0118] wherein, is the muscle contraction rate; is the stimulated muscle strength; is the resting muscle strength.

[0119] Preferably, the calculation data of the muscle contraction rate is based on the corresponding root mean square value.

[0120] The present application is based on the conversion formula of the film pressure sensor voltage and resistance, according to the fact analysis and theoretical derivation, and combined with the actual operation to measure the self-gravity of the stimulation coil module, the muscle strength value in the resting state and the muscle strength value in the stimulation state. Creatively analyze and exclude the influence of the self-gravity of the stimulation coil module and the muscle strength value in the resting state on the actual muscle contraction rate, and improve the detection accuracy of the muscle contraction rate.

[0121] Please refer to Figs. 2-3The application also provides a magnetic field stimulation device based on a thin film pressure sensor, which comprises a thin film pressure sensor working circuit and a stimulation coil module; the thin film pressure sensor working circuit is used for measuring the real-time working resistance of the thin film pressure sensor, and comprises a thin film pressure sensor, a known resistor and an operational amplifier; the thin film pressure sensor is connected to the positive input end of the operational amplifier; the known resistor is connected to the negative input end and the output end of the operational amplifier respectively; and the stimulation coil module is used for generating a high-intensity variable magnetic field and acting on a target muscle group.

[0122] The new magnetic field stimulation device is different from the traditional device using an air bag and an air pressure sensor to measure the muscle strength value, and does not need an additional air pressure sensor, an additional air supply system, and has no risk of air bag burst caused by excessive pressure. Therefore, the scheme using the thin film pressure sensor is simpler and easier to implement. Through the above implementation process and measurement method, the new magnetic field stimulation device applied in muscle medical detection can provide more accurate and reliable measurement results.

[0123] In the several embodiments provided in the present application, it should be understood that the disclosed calculation method can be implemented by other means.

[0124] When the calculation method is implemented in the form of a software function unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, read-only memory), a random access memory (RAM, random access memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0125] In the description of the specification, the description referring to the terms "specifically", "example", "specific implementation process", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0126] The above merely illustrates and describes the structure of the present application, and those skilled in the art can make various modifications or supplements to the described specific embodiments or replace them with similar ways, as long as they do not deviate from the structure of the present application or exceed the scope defined by the present claims, and should belong to the protection scope of the present application.

Claims

1. A method for detecting muscle contractility based on a thin-film pressure sensor, characterized in that: Includes the following steps: S1) Pressure Value Conversion: Since a thin-film pressure sensor is equivalent to a variable resistor, its real-time operating resistance changes when affected by pressure. The conversion relationship between the real-time operating resistance of the thin-film pressure sensor and pressure is as follows: ； In the formula, R is the real-time operating resistance of the thin-film pressure sensor; F is the pressure applied to the thin-film pressure sensor; and K is the conversion coefficient. S2) Gravity measurement: The pressure value of the thin-film pressure sensor is measured when only the gravity of the stimulation coil module is applied, i.e., the gravity of the stimulation coil module. Its calculation formula is expressed as follows: ； In the formula, To stimulate the self-weight of the coil module; K represents the real-time operating resistance of the thin-film pressure sensor under the influence of gravity only from the stimulation coil module; K is the conversion coefficient. S3) Resting muscle strength measurement: The muscle strength produced by the muscle when the stimulation coil module is placed on the muscle and not in operation; Obtain the real-time operating resistance of the thin-film pressure sensor during resting measurement, and calculate the pressure of the thin-film pressure sensor at this time; ； In the formula, The pressure of the thin-film pressure sensor during resting measurement; The real-time operating resistance of the thin-film pressure sensor during resting measurement; The difference between the weight of the stimulation coil module and the pressure of the thin-film pressure sensor in the resting measurement is the resting muscle strength. The calculation formula is as follows: ； In the formula, For resting muscle strength, take the absolute value of the difference; The pressure of the thin-film pressure sensor during resting measurement; To stimulate the self-weight of the coil module; S4) Stimulation of muscle strength measurement: When the stimulation coil module is placed on the muscle and working, the muscle will undergo isometric or isotonic contraction in accordance with the frequency of magnetic field stimulation, causing the pressure of the thin film pressure sensor to change. Obtain the real-time operating resistance of the thin-film pressure sensor during the stimulus measurement, and calculate the pressure of the thin-film pressure sensor at this time. ； In the formula, The pressure of the thin-film pressure sensor is stimulated during measurement; The real-time operating resistance of the thin-film pressure sensor during stimulation measurement; The difference between the self-weight of the thin-film pressure sensor and the stimulation measurement pressure is the stimulation muscle force; its calculation formula is: ； In the formula, To stimulate muscle strength, the absolute value of the difference is taken; The pressure of the thin-film pressure sensor is used to stimulate the measurement; To stimulate the self-weight of the coil module; S5) Muscle contraction rate calculation: The muscle contraction rate is calculated based on the difference between resting muscle strength and stimulated muscle strength; the formula is as follows: ； In the formula, Muscle contraction rate; To stimulate muscle strength; This refers to resting muscle strength.

2. The method for detecting muscle contraction rate based on a thin-film pressure sensor according to claim 1, characterized in that: The method for measuring the real-time operating resistance of the thin-film pressure sensor is as follows: In the circuit of the magnetic field stimulator, a resistive voltage divider is used. The operational amplifier circuit measures and calculates the real-time operating resistance of the thin-film pressure sensor; the calculation formula is as follows: ； In the formula: It is the given input voltage; This is the operating voltage of the thin-film pressure sensor, which is measured using an operational amplifier. It is the real-time operating resistance of the thin-film pressure sensor; The resistance is known.

3. The method for detecting muscle contraction rate based on a thin-film pressure sensor according to claim 1, characterized in that: The real-time operating resistance of the thin-film pressure sensor is measured using the Wheatstone bridge method, and the specific steps are as follows: The thin-film pressure sensor is used as one arm of the bridge, and the other three arms are known resistances; Adjust the bridge circuit to achieve a balanced state; at this point, the output voltage of the bridge circuit is zero. The real-time operating resistance of the thin-film pressure sensor is calculated using the known resistance and the balance condition of the bridge circuit.

4. The method for detecting muscle contraction rate based on a thin-film pressure sensor according to claim 1, characterized in that: The specific values ​​of the conversion coefficients were obtained and verified through calibration experiments.

5. The method for detecting muscle contraction rate based on a thin-film pressure sensor according to claim 1, characterized in that: It also includes using the statistical root mean square (RMS) method to eliminate measurement errors in the self-weight of the stimulation coil module, and using this as a standard for subsequent calculations; the specific method is as follows: By repeating step S2) multiple times to measure the self-gravity, a data set of the real-time operating resistance of the thin-film pressure sensor is obtained. Then, the set of self-gravity data of the stimulation coil module is calculated. Finally, calculate its root mean square value. ； In the formula, This is the root mean square value of the self-weight of the stimulation coil module; The value of the self-weight of the stimulation coil module; This represents the total number of datasets.

6. The method for detecting muscle contraction rate based on a thin-film pressure sensor according to claim 1, characterized in that: By repeating step S3) resting muscle strength measurement multiple times, the statistical root mean square value method is used to eliminate the measurement error of resting muscle strength and to serve as the standard for subsequent calculations.

7. The method for detecting muscle contraction rate based on a thin-film pressure sensor according to claim 1, characterized in that: By repeating step S4) multiple times to measure muscle strength, the root mean square (RMS) method is used to eliminate measurement errors of the stimulated muscle strength and to serve as the standard for subsequent calculations.

8. The method for detecting muscle contraction rate based on a thin-film pressure sensor according to any one of claims 5-7, characterized in that: The calculation data for the muscle contraction rate is based on the corresponding root mean square value.

9. A magnetic field stimulator based on a thin-film pressure sensor, used to implement the muscle contraction rate detection method based on a thin-film pressure sensor as described in any one of claims 1 to 8, characterized in that: Includes the working circuit of the thin-film pressure sensor and the stimulation coil module; The working circuit of the thin-film pressure sensor is used to measure the real-time operating resistance of the thin-film pressure sensor, and includes the thin-film pressure sensor, a known resistor, and an operational amplifier; A thin-film pressure sensor is connected to the positive input terminal of an operational amplifier; known resistors are connected to the negative input and output terminals of the operational amplifier respectively. The stimulation coil module is used to generate a high-intensity, changing magnetic field and act on the target muscle group.

Images