Muscle pressure intensity and complex impedance detection device and muscle impedance index measuring and calculating method

Abstract

The invention provides a muscle pressure intensity and complex impedance detection device and a muscle impedance index measuring and calculating method. The detection device comprises an electrode needle A, an electrode needle B, a pressure intensity detection module and a PC terminal. According to the muscle pressure intensity and complex impedance detection device, dual detection of resistance and pressure intensity is achieved for muscles, intramuscular pressure and multi-frequency impedance of the muscles are directly and synchronously measured in vivo, more objective quantitative data are provided for medical diagnosis, and the current situation that subjective judgment depends on is fundamentally changed. According to the method, the'pressure 'reflecting the muscle macromechanical state is further combined with the'impedance' reflecting the tissue microscopic components, and the impedance is integrally fused by PI-Index, so that more comprehensive, more accurate and more visual pathological state assessment is provided; the direct comparison of the pressure intensity, the impedance spectrum and the PI-Index of the affected side and the healthy side is realized, differential diagnosis can be effectively carried out, an accurate quantitative index is provided for the comparison of effects before and after treatment, and the clinical diagnosis and treatment precision is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of medical testing technology, and in particular to a device for detecting muscle pressure and complex impedance, and a method for calculating the muscle impedance index. Background Technology

[0002] Muscle pressure and impedance testing can enable accurate diagnosis of certain specific diseases, such as piriformis syndrome. Piriformis syndrome is a common condition caused by hypertrophy, spasm, or anatomical variations of the piriformis muscle compressing the sciatic nerve, resulting in pain and numbness in the buttocks and leg. Its clinical diagnosis currently faces significant challenges, relying primarily on subjective clinical symptom inquiries (such as buttock pain and sciatica) and physical examinations (such as the FAIR test), lacking an objective, quantifiable gold standard for diagnosis.

[0003] The existing technology has the following significant drawbacks: 1. High degree of diagnostic ambiguity: The above-mentioned subjective examination methods lack specificity and sensitivity, and are easily confused with diseases such as lumbar disc herniation and sacroiliac joint dysfunction, leading to misdiagnosis and missed diagnosis.

[0004] 2. Lack of quantitative indicators: It is impossible to classify the severity of the disease, and it is also difficult to make accurate and objective comparisons and assessments of the efficacy before and after treatment (such as physical therapy, injections, surgery).

[0005] 3. Limited technical means: Existing imaging techniques (such as MRI and ultrasound) mainly observe morphological changes and are difficult to capture real-time physiological changes in muscle function (such as spasm and edema). Although electromyography can assess nerve function, it cannot directly reflect the pathophysiological state of the muscles themselves.

[0006] To address the diagnostic challenges of these diseases, current technologies lack precise measurement equipment for muscle pressure and resistance index, and also lack a quantitative indicator for accurate diagnosis. Summary of the Invention

[0007] The purpose of this invention is to provide a muscle pressure and complex impedance detection device and a method for calculating the muscle impedance index, which can directly, objectively, and quantitatively assess muscle condition and provide accurate diagnostic indicators for muscle-related diseases.

[0008] To achieve the above objectives, the present invention proposes a muscle pressure and complex impedance detection device, comprising electrode needle A, electrode needle B, pressure detection module and PC terminal; Electrode A is a hollow stainless steel needle tip with side holes, and electrode B is a solid stainless steel needle tip; the vent at the tail end of electrode A is connected to the pressure detection module, and the pressure detection module is connected to the microcontroller on the PC through the pressure detection circuit; electrode A and electrode B are connected to the microcontroller on the PC through the impedance detection circuit.

[0009] Furthermore, the needle tube surfaces of both electrode needle A and electrode needle B are coated with an insulating layer; a side hole is opened on the side of the tip of electrode needle A.

[0010] Furthermore, the pressure detection module includes a sealed pressure detection chamber and a pressure sensor; the pressure sensor is fixed inside the pressure detection chamber, the vent at the end of electrode needle A is inserted into the pressure detection chamber, and the wire hole of the pressure detection chamber is sealed with sealant; the pressure sensor is connected to the microcontroller via wires.

[0011] Furthermore, the end of the pressure testing chamber is connected to a testing channel filling component; The filling assembly for the detection channel includes a syringe connecting tube inserted into the end of the pressure detection chamber, and a valve located on the syringe connecting tube.

[0012] Furthermore, both the impedance detection circuit and the pressure detection circuit are equipped with ADCs; Electrode needle B is connected in series with a current sensing resistor; the impedance detection circuit monitors the injected current by measuring the voltage across the current sensing resistor.

[0013] Furthermore, the PC side includes an integrated microcontroller, DDS, DAC, and constant current source; The microcontroller sends instructions to the DDS to generate a digital signal of a specific frequency; it receives impedance and pressure digital signals from the ADC and performs data processing. The DDS generates sinusoidal digital sequences of different frequencies under the control of a microcontroller, and the sinusoidal digital sequences are converted into corresponding analog voltage signals by a DAC. The constant current source receives the analog voltage signal output by the DAC and converts it into an effective value AC constant current signal with constant amplitude that is unaffected by the load, which is then injected into the muscle tissue through electrode needles A and B.

[0014] Furthermore, the sinusoidal digital sequences include 5kHz, 50kHz, 100kHz, and 200kHz sinusoidal digital sequences; the bio-excitation current is 50µA.

[0015] Furthermore, the PC also includes a display unit that displays the detected pressure and impedance information.

[0016] This invention also proposes a method for calculating the muscle resistance index, comprising the following steps: S1: Insert electrode needles A and B of the muscle pressure and complex impedance detection device into the muscle tissue; S2: Obtain the resistance at each frequency point and reactance ; S3: Calculate the impedance modulus at each frequency point based on resistance and reactance. ; S4: Calculate the phase angle at each frequency point based on the impedance modulus value. ; S5: Based on phase angle The phase weighting factor at each frequency point is calculated. ; S6: Based on the formula: The muscle resistance index was calculated.

[0017] Compared with the prior art, the advantages of the present invention are: 1. The muscle pressure and complex impedance detection device of the present invention realizes dual detection of resistance and pressure in muscles, and realizes in vivo, direct and synchronous measurement of intramuscular pressure and multi-frequency impedance of muscles, providing more objective quantitative data for medical diagnosis, fundamentally changing the status quo of relying on subjective judgment.

[0018] 2. The device of the present invention combines "pressure," which reflects the macroscopic mechanical state of muscles, with "impedance," which reflects the microscopic components of tissues, by detection. The impedance is integrated into a whole using the PI-Index, providing a more comprehensive, accurate, and intuitive assessment of the pathological state. Furthermore, it can compare the pressure, impedance spectrum, and PI-Index of the affected and healthy sides, which can effectively perform differential diagnosis and provide precise quantitative indicators for comparing the effects before and after treatment, greatly improving the level of clinical diagnosis and treatment.

[0019] 3. The muscle pressure and complex impedance detection device of the present invention is simple to operate and accurate in measurement, effectively reducing the operational difficulty for medical staff and improving diagnostic efficiency. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the muscle pressure and complex impedance detection device in Embodiment 1 of the present invention.

[0021] Figure 2 This is a schematic diagram of the internal structure of the muscle pressure and complex impedance detection part in Embodiment 1 of the present invention.

[0022] Figure 3 This is a schematic diagram of the filling state of the muscle pressure and complex impedance detection device before use in Embodiment 1 of the present invention.

[0023] Figure 4 This is a schematic diagram of the detection circuit in Embodiment 1 of the present invention.

[0024] Figure 5 This is a flowchart of the puncture procedure for the muscle pressure and complex impedance detection device in Embodiment 2 of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be further described below.

[0026] Example 1: like Figure 1 As shown, this invention proposes a muscle pressure and complex impedance detection device, which consists of three parts: a PC terminal, a muscle pressure and complex impedance detection part, and an auxiliary locator. Among them, the muscle pressure and complex impedance detection section, such as Figure 2 As shown, it consists of the following parts: Electrode A1: An impedance detection electrode made of hollow stainless steel capillary tube with side holes, 0.5-0.9 mm in diameter. Its tip is a blind hole. This needle, together with electrode B, forms an impedance detection circuit and also has a pressure detection function. The tip of electrode A1 has a side hole 2, 5-6 mm from the tip, smooth and without nicks or burrs. The side hole prevents blockage when piercing the patient's muscle tissue, thus affecting pressure detection. The middle part of electrode A1 is a pressure detection channel 3: one end of the pressure detection channel 3 communicates with the side hole 2 on electrode A1, and the other end communicates with the pressure detection chamber 23. The outer surface of the needle tube of electrode A1 is coated with polytetrafluoroethylene insulating material as the first insulating coating layer 4. The A1 part (needle tip) is exposed without coating to maintain the needle's conductivity. A wire connection point 5 is provided at the tail of electrode A1, connecting the wire to the impedance detection circuit.

[0027] Electrode needle B25: Electrode needle B25 is a solid stainless steel needle-shaped impedance detection electrode with a diameter of 0.5-0.9 mm. This needle, together with electrode needle A, forms an impedance detection circuit. A wire connection point 22 is provided at the tail end of electrode needle B25, and the wire is connected to the electrode needle by soldering. Similar to electrode needle A1, the outside of electrode needle B25 is coated with polytetrafluoroethylene insulating material, while part of A1 is exposed (uncoated) to maintain the conductivity of the needle.

[0028] The lower housing 6 and the upper housing 9 of the needle handle together form the needle handle, which are sealed and adhered to each other by the pressure detection chamber sealant 11 and the electrode lead chamber adhesive material 21; making it easy for medical staff to hold. The needle handle is divided into two independent chambers by the baffle 19, namely the pressure detection chamber 23 and the electrode lead chamber 20. The pressure detection chamber 23 must be sealed, while the electrode lead chamber 20 does not need to be sealed.

[0029] The pressure sensor 8 is attached to the bottom of the pressure detection chamber 23 by adhesive material 7. The maximum range of the pressure sensor is less than or equal to 40 kPa. The sensor is for single use only. Since the electrode needle is inserted into the skin for single use only, the sensor part also needs to be replaced. The tail end of the pressure detection channel 3 of the electrode needle A1 is connected to the inside of the pressure detection chamber 23. A syringe connecting tube 15 is inserted into the end of the pressure detection chamber 23. A water valve 14 is installed inside the syringe connecting tube 15. The water valve 14 is connected to a water valve switch 16.

[0030] The electrode lead housing 20 connects to the tail end of the electrode needle B25. The electrode lead housing 20 is a process compartment without sealing requirements, used to lead out the wires connected to the electrode needle B. Wire holes are provided in both the electrode lead housing 20 and the pressure detection chamber 23. The output wire 13 at the tail end of the electrode needle B25 passes through the baffle wall 19 and the wire holes on the pressure detection chamber 23, connecting to the external output wire connector 12. The wires of the pressure sensor 8 and the electrode needle A1 pass through the wire holes on the pressure detection chamber 23, connecting to the external output wire connector 12. The output wire connector 12 is a plug through which the lead wires of the detection electrode and the lead wires of the pressure sensor in the disposable puncture needle are connected to the PC terminal. The wire holes in the baffle wall 19 are sealed with electrode needle B lead wire sealant 17, and the wire holes on the pressure detection chamber 23 are sealed with output wire sealant 12, thus ensuring that the pressure detection chamber becomes a sealed chamber and preventing air leakage from affecting the pressure detection effect.

[0031] In this embodiment, the effective length of the electrode needle is between 50-150mm, depending on the patient, such as fat, thin, adult, or child, and is divided into 16 length specifications with a step size of 10mm; the needle spacing of the electrode needle is between 5-8mm, and is divided into 4 spacing specifications with a step size of 1mm.

[0032] like Figure 1 As shown, to facilitate the insertion of the muscle pressure and complex impedance detection section into the human muscle, this invention includes an auxiliary locator 27. The auxiliary locator comprises two parallel positioning accessory baffles 26 and 28; two needle holes are provided between the positioning accessory baffles 26 and 28, as shown... Figure 1 As shown, two needle holes are respectively fitted onto electrode needles A1 and B25 for positioning. As an auxiliary tool during needle insertion, the material has high electrical resistance insulation. The distance between the outer surfaces of the two positioning baffles is 5-10 mm, and the diameter of the needle hole in the middle is 0.6-1.0 mm. Because the puncture needles are slender, they are easily misaligned during puncture, causing them to lose their relative parallelism. This results in inconsistent relative angles between the two needles during each puncture, affecting the comparability of clinical data between each test. Therefore, this accessory was designed. In use, the auxiliary positioning device is first fitted onto electrode needles A and B.

[0033] like Figure 1 As shown, the PC end is a device host 32, and its outer surface includes the following structure: host socket 29: host socket 29 is used to connect the output line connector 12, thereby connecting the pressure detection circuit and the impedance detection circuit to the microcontroller signal. On the other side of the device host, there is another host socket 33, which can simultaneously connect two sets of muscle pressure and complex impedance detection parts, and can simultaneously perform impedance and pressure detection on the healthy side and the diseased side of the patient to achieve comparison.

[0034] The outer surface of the main unit of the device is equipped with an LCD screen 30, which is used to display data including the detected impedance value, pressure value and PI-Index.

[0035] Main Unit Buttons 31: The main unit includes at least four buttons: power on / off button, affected side data latch button, healthy side data latch button, and clear button. The latch button is used to latch the pressure and impedance data of the affected and healthy sides on the display screen for easy comparison by doctors. The clear button is used to clear the latched data of the current test to start a new test; In this embodiment, as Figure 4 As shown, the PC module integrates an impedance detection circuit, a pressure detection circuit, a microcontroller, a DDS, a DAC, and a constant current source. The functions of each module are as follows: Microcontroller: As the system brain, it employs a DSP or SPGA system to control the entire measurement process. It sends instructions to the DDS to generate digital signals of a specific frequency; receives impedance and pressure digital signals from the ADC, performs data processing, calculates the piriformis impedance index, and drives the display unit.

[0036] Direct Digital Synthesizer and Digital-to-Analog Converter (DDS): Under the control of a microcontroller, the DDS accurately generates a multi-frequency sinusoidal digital sequence. This digital sequence is then converted into a corresponding analog voltage signal via the DAC, serving as the excitation source for subsequent circuits.

[0037] Constant current source: Receives the analog sinusoidal voltage output from the DAC and converts it into a constant-amplitude, load-independent 50µA AC constant current signal. This constant current signal is a safe bio-excitation current that will be injected into human muscle tissue.

[0038] The current sensing resistor and impedance detection circuit: The constant current source output current flows through the human tissue (piriformis muscle) and a precision current sensing resistor connected in series with electrode needle B; the impedance detection circuit monitors and ensures the accuracy and stability of the injected current by measuring the voltage across this sampling resistor. Simultaneously, the circuit measures the voltage applied across the human tissue and calculates the complex impedance of the tissue by dividing it by the known current. The built-in ADC (analog-to-digital converter) converts this analog impedance signal into a digital signal for processing by the microcontroller.

[0039] Pressure detection circuit: Pressure sensor 8 converts pressure changes within the piriformis muscle into a weak analog electrical signal. This circuit amplifies and filters this signal, then converts it into a digital pressure value via a built-in ADC, which is then uploaded to the microcontroller.

[0040] In this embodiment, the detection method of the muscle pressure and complex impedance detection device is as follows: Figure 3 As shown, first insert the sterile syringe into the syringe connecting tube 15, open the water valve 14, and fill the pressure detection chamber 23 and electrode needle A1 with sterile physiological saline to remove air and bubbles that interfere with pressure detection. During filling, the disposable puncture needle, sterile container and syringe must be kept vertical. Then, the electrode needle A1 is immersed as much as possible in the tubular sterile container filled with sterile physiological saline. Connect a sterile syringe with a capacity of 20ml to the syringe connecting end of the water valve, and draw physiological saline through the syringe until the pressure detection channel is fully filled. After filling, electrode needles A1 and B25 of the two sets of muscle pressure and impedance detection sections are inserted into the muscles of the affected and healthy sides. Pressure sensor 8 transmits the pressure value to the microcontroller through the pressure detection circuit. The microcontroller detects the pressure values ​​of the muscles on the healthy and affected sides in real time. The microcontroller controls the output of AC constant current signals of different frequencies as a safe bio-excitation current, which will be injected into the human muscle tissue. The impedance detection circuit detects the impedance information of the muscles on the healthy and affected sides, and the microcontroller calculates the PI-Index of the healthy and affected sides. By comparing the detection values ​​of the healthy and affected sides, the disease of the affected side muscle can be detected.

[0041] Example 2 To further illustrate the technical effects of the present invention, the following section will demonstrate the application of the muscle pressure and complex impedance detection device in the detection of piriformis syndrome.

[0042] I. Equipment Used: The muscle pressure and complex impedance detection device as described in Example 1 is used, such as... Figure 4 As shown, the test includes two groups of muscle pressure and impedance measurement sections, collecting pressure and impedance information of the piriformis muscle on the healthy and affected sides, respectively; for ease of reference... Figure 5 The piriformis muscle test shown here uses a 5mm conductive portion of the electrode needle. The purpose of this is to effectively detect the impedance of the piriformis muscle while avoiding the influence of the gluteus maximus and other surrounding tissues.

[0043] II. Selection of detection frequency: Select four frequency points: 5kHz, 50kHz, 100kHz, and 200kHz; The frequency of the sinusoidal alternating current used for detection is not arbitrarily selected, but rather based on the physiological principle of muscle bioelectrical impedance spectrum. This carefully designed and clinically validated frequency combination aims to capture the characteristic electrical information of the piriformis muscle under different pathological states with a minimal number of sampling points, resulting in a streamlined and efficient measurement system. By simultaneously analyzing the impedance spectrum at these four characteristic frequency points and combining it with intramuscular pressure data, clinicians can accurately distinguish between different dominant pathological states of the piriformis muscle, such as edema, spasm, and fibrosis. This allows for a leap from empirical diagnosis to quantitative, pathophysiologically mechanistic diagnosis, providing precise guidance for subsequent personalized treatment. The selected four frequency points—5kHz, 50kHz, 100kHz, and 200kHz—constitute a simplified spectrum from low to mid-high frequencies. The selection criteria and clinical significance are as follows: Selection criteria 2.1 Key regions covering intracellular and extracellular fluid information; According to bioelectrical impedance theory, the ability of current to penetrate cell membranes varies at different frequencies. Low-frequency currents (such as 5 kHz) mainly flow through the highly conductive extracellular fluid and cannot penetrate the cell membrane; their impedance characteristics primarily reflect changes in extracellular fluid volume, such as tissue edema and inflammation. As the frequency increases (to 50 kHz, 100 kHz, 200 kHz), the current begins to penetrate the cell membrane, and its impedance characteristics reflect the total volume of intracellular and extracellular fluids. These four selected frequency points effectively cover the transition range from primarily reflecting extracellular fluid to reflecting total intracellular fluid, providing the necessary spectral data foundation for distinguishing different pathophysiological states.

[0044] 2.2 Optimizing the balance between signal-to-noise ratio and measurement depth: At frequencies that are too low (e.g., <1kHz), the current is more easily attenuated in the skin and subcutaneous tissue, resulting in a poor signal-to-noise ratio and susceptibility to interference from electrode polarization effects. At frequencies that are too high (e.g., >1MHz), the current distribution tends to be surface-based, making it difficult to effectively probe deep piriformis muscle tissue, and increasing the complexity of the measurement system. The selected range of 5kHz to 200kHz represents the optimal window for achieving the best signal-to-noise ratio and the most reliable technical implementation while ensuring that the current can effectively penetrate deep muscle tissue.

[0045] 2.3 Targeted design based on muscle tissue relaxation characteristics: Skeletal muscle tissue possesses a specific β-dispersion range (typically in the kHz to MHz range), primarily determined by the capacitive properties of the cell membrane. Four selected frequency points precisely cover the critical rising edge portion of this β-dispersion range. Within this range, the amplitude and phase of impedance are most sensitive to frequency changes, enabling the maximal capture of variations in cell membrane capacitance and conductivity caused by muscle spasms, edema, or fibrosis.

[0046] Clinical significance The measurement results at each frequency point are highly correlated with specific pathological changes in the piriformis muscle, collectively forming a multidimensional diagnostic profile: The 5kHz frequency point—a sensitive indicator of extracellular fluid edema: the impedance (especially the resistive component) at this frequency is extremely sensitive to increases in interstitial fluid. When the piriformis muscle experiences acute inflammation or edema, extracellular fluid increases significantly, increasing conductive pathways and leading to a significant decrease in impedance amplitude at 5kHz. Therefore, this point is a core indicator for assessing the resolution of acute edema and inflammation.

[0047] 50kHz and 100kHz frequency points—a comprehensive assessment of overall tissue condition: These two mid-frequency points reflect the mixed information of intracellular and extracellular fluids and are key to assessing the overall physiological state of muscles. They are highly sensitive to changes in muscle fullness, ionic environment, and cellular structural integrity. In piriformis muscle spasm, due to local ischemia and accumulation of metabolic products, the intracellular environment changes, triggering characteristic changes in impedance phase angles at these two frequency points. They are important indicators for distinguishing spasm from simple edema.

[0048] 200kHz Frequency Point—A Trend Observation Window for Cellular Structural Integrity: As the highest point in this spectrum, the impedance at this frequency more closely reflects the overall water content of the tissue. In the progression of chronic piriformis syndrome or fibrosis, muscle cells with normal capacitance properties are replaced by poorly conductive fibrous connective tissue. This change leads to an increase in impedance amplitude and a decrease in the absolute value of the phase angle across the entire spectrum, particularly around 200kHz. Data at this point provides an early trend assessment of the disease's chronic progression.

[0049] III. Pressure Sensor Range In achieving accurate measurement of intramuscular pressure in the piriformis muscle, the selection of the pressure sensor is one of the core aspects to ensure data accuracy. Two key requirements are placed on the performance of the pressure sensor: first, media compatibility, requiring safe and direct contact with sterile saline; and second, range adaptability, meaning its measurement range must be highly matched to the physiological and pathological pressure range of the piriformis muscle.

[0050] Theoretical analysis and previous studies both indicate that selecting a measurement range of 0-15 kPa is the ideal approach to achieve optimal measurement. This is primarily based on the following physiological and pathological foundations: 3.1 Coverage of Resting and Pathological Ranges: Existing literature and preliminary experimental data indicate that the resting intramuscular pressure of the piriformis muscle in healthy adults is typically between 0 and 2 kPa. When the muscle is in a state of spasm, tension, or inflammation, its internal pressure can significantly increase to pathological levels of 5-8 kPa. Even in extreme cases of severe spasm, the pressure rarely exceeds 12 kPa. Therefore, a range of 0-15 kPa can fully cover the entire pressure range from the normal resting state to severe pathological states.

[0051] 3.2 Optimizing Measurement Accuracy and Signal-to-Noise Ratio: Sensor accuracy is typically expressed as a percentage of full scale (e.g., ±0.5% FS). For a sensor with a full scale of 15 kPa, the absolute error is significantly smaller than that of a sensor with a full scale of 40 kPa. When measuring critical resting pressure (~2 kPa) or mildly to moderately elevated pathological pressure (~5 kPa), a 15 kPa sensor provides higher resolution and a better signal-to-noise ratio, enabling the sensitive detection of minute, clinically significant pressure changes before and after treatment.

[0052] IV. Data Collection Time The patient muscle physiological data acquisition process of this invention has been carefully designed and clinically validated to overcome the inherent interference of invasive measurements and ensure the stability and representativeness of the acquired data. Its core lies in employing a time-division, segmented acquisition strategy that prioritizes stabilization before acquisition and impedance before pressure.

[0053] 4.1: Acquisition timing of multi-frequency impedance data (total duration 20 seconds) The impedance measurements were performed sequentially at four preset frequency points (5kHz, 50kHz, 100kHz, 200kHz). At each frequency point, the measurement was performed for 5 seconds, and the average impedance over those 5 seconds was calculated in real time as the final effective value for that frequency point. The total measurement time for the four frequency points was 20 seconds.

[0054] 4.2: Scientific Basis of Timing Design To ensure statistical significance: Single instantaneous measurements are susceptible to interference from muscle fiber micro-twitches, vascular pulsation, and measurement noise. Taking a continuous 5-second measurement and averaging the results can effectively smooth out these random fluctuations, extract an impedance value that stably represents the tissue electrical properties at that frequency, and significantly improve the signal-to-noise ratio and repeatability of the data.

[0055] Meeting the requirements of spectral scanning: The impedance of biological tissues exhibits dispersion characteristics, revealing different physiological information at different frequencies. The 20-second total duration used in this invention is sufficient to complete a simplified spectral scan from low to high frequencies, while ensuring that the entire procedure remains within clinically acceptable limits.

[0056] 4.3: Timing of intramuscular pressure data acquisition (last 5 seconds read) Intramuscular pressure measurement and impedance measurement begin simultaneously, but the effective data acquisition window is deliberately set in the last 5 seconds of the entire 20-second measurement cycle.

[0057] 4.4: Physiological and Pathological Basis of Timing Design Avoiding Needle-Induced Stress: The physical act of inserting a needle into the piriformis muscle is itself a form of trauma, immediately triggering acute stress contractions in the muscle. This results in a transient, non-pathological, significant increase in intramuscular pressure in the initial phase after insertion (e.g., the first 10-15 seconds). The pressure value at this stage reflects "traumatic stress pressure," rather than the muscle's baseline or pathological tension. As time progresses (usually 15-20 seconds after insertion), due to neural adaptation and local feedback regulation, the acute stress response of the muscle gradually weakens and enters a relatively stable compensatory period. The average pressure value read within the last 5-second time window can minimize interference from the puncture trauma itself, more accurately reflecting the degree of pathological tonic spasm or resting tension of the piriformis muscle. This ingenious design separates procedural interference from pathological signals and is key to the reliability of this measurement method.

[0058] 4.5: Spatiotemporal Synchronization and Correlation of Multimodal Data A key feature of this invention is that the pressure and impedance signals originate from the same puncture site and are acquired with high temporal synchronization. This lays a solid foundation for establishing the intrinsic correlation between the two parameters. For example, during the final 5-second period of stable pressure reading, the system is simultaneously acquiring impedance data at 100kHz and 200kHz. This spatiotemporal consistency makes subsequent data fusion analysis (such as calculating the PI-Index) and the exploration of the biomechanical-electrical coupling relationship of the muscle highly valuable, enabling a deeper understanding of the pathophysiological state of the piriformis muscle.

[0059] 5. Impedance Calculation This device calculates the complex impedance of the healthy and diseased sides as modulus values ​​and displays them, namely the impedance modulus values ​​of the healthy side at four frequencies and the impedance modulus values ​​of the diseased side at four frequencies; then it calculates and displays the piriformis muscle impedance index (PI-Index) of the healthy and diseased sides; at the same time, it displays the pressure values ​​within the piriformis muscle of the healthy and diseased sides.

[0060] 5.1: Calculation process The following calculations These correspond to 5kHz, 50kHz, 100kHz, and 200kHz respectively.

[0061] 5.2: Calculation of complex impedance modulus (Unit: Ohms) The obtained complex impedance value Calculate the complex impedance modulus using the following formula.

[0062] ;

[0063] In the formula, j is the imaginary unit. After the calculation is completed, the impedance modulus values ​​of the healthy side and the affected side are... Displayed on the LCD screen respectively 5.3: Calculate the phase angle at each frequency point (Unit: radians) ;

[0064] in It is a piecewise function ;

[0065] Calculate the phase weighting factor

[0066] We need a weighting mechanism so that contributions from phases closer to zero (or positive values, indicating more fluid behavior / edema) are suppressed, while contributions from phases more negative (indicating more cell membrane behavior / healthy tissue) are enhanced. Using an exponential function with a negative phase is a good choice. ;

[0067] here It is an amplification factor used to adjust the sensitivity to phase differences. Based on the electrode needle parameters and 50 μA constant current of this invention, it was verified through sample testing. .

[0068] Calculate the piriformis muscle resistance index PI-Index (unitless). The PI-Index value is calculated using the following formula. ;

[0069] Real-world application data: Calculate the modulus and phase

[0070] Use formula calculate The unit is ohms, and the formula is used. calculate (Unit: radians) After the calculation is completed, the impedance modulus values ​​(i.e. amplitude values) of the healthy side and the affected side are displayed on the LCD screen.

[0071] Contralateral piriformis muscle

[0072] piriformis muscle on the affected side

[0073] Calculate the phase weighting factor Use formula in

[0074] Unaffected piriformis muscle: ; ; ; ;

[0075] piriformis muscle on the affected side: ; ; ; ;

[0076] Calculate PI-Index Use formula ;

[0077] piriformis muscle PI-Index Numerator = (0.395 × 67.08) + (0.363 × 51.48) + (0.395 × 44.72) + (0.445 × 38.08) = 26.52 + 18.67 + 17.68 + 16.92 = 79.79 Denominator = 0.395 + 0.363 + 0.395 + 0.445 = 1.598 ;

[0078] piriformis muscle PI-Index on the affected side The numerator is calculated as follows: (0.525 × 47.43) + (0.558 × 41.76) + (0.597 × 39.29) + (0.646 × 36.88) = 24.88 + 23.28 + 23.47 + 23.81 = 95.44 Denominator = 0.525 + 0.558 + 0.897 + 0.646 = 2.326 ;

[0079] After the calculation is completed, the PI-Index values ​​(piriformis muscle resistance index) of the healthy side and the affected side are displayed on the LCD screen.

[0080] Significance of the muscle resistance index PI-Index This index can be understood as the phase-weighted average impedance amplitude.

[0081] If the affected tissue is edematous (extracellular fluid increases), its impedance amplitude It will decrease, and at the same time, the phase It will shift towards zero (negative values ​​become smaller). Both of these changes will cause the calculated PI-Index value to decrease.

[0082] If the affected tissue is fibrotic / atrophic (reduced conductive pathways), its impedance amplitude It may rise, but the phase It may also change due to cell structure damage. In this case, the direction of change in PI-Index depends on the combined effect of amplitude and phase changes.

[0083] If the PI-Index of the affected side is less than or equal to the PI-Index of the healthy side, it strongly suggests edema / inflammation on the affected side; if the PI-Index of the affected side is greater than or equal to the PI-Index of the healthy side, it may suggest fibrosis / chronic lesions on the affected side; if the two are close, it may indicate that the muscle condition is not significantly different in terms of macroscopic electrical properties.

[0084] The above are merely preferred embodiments of the present invention and do not constitute any limitation on the present invention. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and content disclosed in the present invention without departing from the scope of the present invention shall be deemed to have remained within the protection scope of the present invention.

Claims

1. A device for detecting muscle pressure and complex impedance, characterized in that, Includes electrode needle A, electrode needle B, pressure detection module and PC terminal; Electrode A is a hollow stainless steel needle tip with side holes, and electrode B is a solid stainless steel needle tip; the vent at the tail end of electrode A is connected to the pressure detection module, and the pressure detection module is connected to the microcontroller on the PC through a pressure detection circuit; electrode A and electrode B are connected to the microcontroller on the PC through an impedance detection circuit.

2. The muscle pressure and complex impedance detection device according to claim 1, characterized in that, The needle tube surfaces of both electrode needle A and electrode needle B are coated with an insulating layer; the side hole is opened on the side of the tip of electrode needle A.

3. The muscle pressure and complex impedance detection device according to claim 1, characterized in that, The pressure detection module includes a sealed pressure detection chamber and a pressure sensor; the pressure sensor is fixed inside the pressure detection chamber, the vent at the tail end of the electrode needle A is inserted into the pressure detection chamber, and the wire hole of the pressure detection chamber is sealed with sealant; the pressure sensor is connected to the microcontroller via a wire.

4. The muscle pressure and complex impedance detection device according to claim 3, characterized in that, The end of the pressure detection chamber is connected to a detection channel filling component; The detection channel filling assembly includes a syringe connecting tube inserted into the end of the pressure detection chamber, and a valve provided on the syringe connecting tube.

5. The muscle pressure and complex impedance detection device according to claim 4, characterized in that, Both the impedance detection circuit and the pressure detection circuit are equipped with ADCs; The electrode needle B is connected in series with a current detection resistor; the impedance detection circuit monitors the injected current by measuring the voltage across the current detection resistor.

6. The muscle pressure and complex impedance detection device according to claim 5, characterized in that, The PC terminal includes the microcontroller, DDS, DAC and constant current source integrated inside; The microcontroller sends instructions to the DDS to generate a digital signal of a specific frequency; it also receives impedance and pressure digital signals from the ADC and performs data processing. The DDS generates sinusoidal digital sequences of different frequencies under the control of the microcontroller, and the sinusoidal digital sequences are converted into corresponding analog voltage signals by the DAC. The constant current source receives the analog voltage signal output by the DAC and converts it into an effective value AC constant current signal with constant amplitude and unaffected by load, which is then injected into the muscle tissue through the electrode needles A and B.

7. The muscle pressure and complex impedance detection device according to claim 6, characterized in that, The sine wave digital sequence includes sine wave digital sequences of 5kHz, 50kHz, 100kHz, and 200kHz; the bio-excitation current is 50 microamps.

8. The muscle pressure and complex impedance detection device according to claim 6, characterized in that, The PC terminal also includes a display unit, which displays the detected pressure and impedance information.

9. A method for calculating the muscle resistance index, characterized in that, The muscle pressure and complex impedance detection device as described in any one of claims 1-7 is characterized by comprising the following steps: S1: Insert electrode needles A and B of the muscle pressure and complex impedance detection device into the muscle tissue; S2: Obtain the resistance at each frequency point and reactance ; S3: Calculate the impedance modulus at each frequency point based on the aforementioned resistance and reactance. ; S4: Calculate the phase angle at each frequency point based on the impedance modulus value. ; S5: Based on the phase angle The phase weighting factor at each frequency point is calculated. ; S6: Based on the formula: The muscle resistance index was calculated.

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