A low power consumption neuromuscular stimulator

Abstract

The present invention discloses a low-power consumption neuromuscular stimulator, comprising a power supply module, a low-voltage boosting feedback control module, a constant voltage to constant current module, an on-off feedback circuit, a microcontroller and N pairs of electrodes, wherein N is an integer greater than or equal to 1, and each pair of electrodes comprises an input electrode and an output electrode. The present invention can detect and feedback the current voltage in real time through the low-voltage boosting feedback control module, prevent the boosting from being too high, damage related components, and shorten the charging time, thereby greatly reducing the power consumption of the instrument in the working state; when the stimulator is in the working state, when the electrode is disconnected or the electrode falls off, the microcontroller can timely monitor the abnormality of the amplitude or frequency of the stimulation current through the on-off feedback circuit set at the output electrode end, and instruct the low-voltage boosting feedback control module to close, so that the stimulator of the present invention has extremely low power consumption.

Description

Technical Field

[0001] The invention relates to a neuromuscular stimulator and belongs to the field of medical instruments. Background Art

[0002] A neuromuscular stimulator is a medical device that uses low- to medium-frequency electrical stimulation pulses to stimulate the patient's muscles or nerves. It is currently widely used in the recovery and treatment of diseases such as cerebral fatigue, brain trauma, hemiplegia, and paraplegia.

[0003] Neuromuscular stimulators are usually powered by disposable dry batteries, but dry batteries have limited storage capacity. Since the impedance of biological tissues is basically between 2KΩ and 20MΩ, the stimulation output module of the stimulator needs to have a higher voltage source, usually between 100V and 130V. Therefore, it is necessary to build a switching circuit and an LC boost circuit through components such as capacitors and inductors to convert the low-voltage power supply into a high-voltage power supply. However, in the process of boosting low voltage to high voltage, the long charging time required for boosting and the excessively high boost value may cause damage to related components and waste the power supply energy of the stimulator. Therefore, in the process of boosting low voltage to high voltage, it is necessary to implement feedback control on the boosting process, shorten the charging time during the boosting process, reduce the energy consumption of the stimulator, and extend the service life of the stimulator. In addition, during the use of the stimulator, the stimulator should be able to automatically detect the possible disconnection of the stimulation electrode or the detachment of the electrode patch and shut down the circuit to reduce energy consumption. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a low-power neuromuscular stimulator.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: the low-power consumption neuromuscular stimulator of the present invention includes a power supply module, a low-voltage boosting feedback control module, a constant voltage to constant current module, an on-off feedback circuit, a microcontroller and N pairs of electrodes, N is an integer greater than or equal to 1; each pair of electrodes includes an input electrode and an output electrode, each input electrode is respectively electrically connected to the output end of the constant voltage to constant current module, and each output electrode is respectively electrically connected to the input end of the on-off feedback circuit; the output end of the low-voltage boosting feedback control module is connected to the input end of the constant voltage to constant current module; the power supply module is connected to the low-voltage boosting feedback circuit The low voltage boost feedback control module and the microcontroller are connected respectively; the low voltage boost feedback control module, the constant voltage to constant current module, and the on-off feedback circuit are connected respectively to the microcontroller; the microcontroller can instruct the low voltage boost feedback control module to increase the voltage to a preset high voltage and then output it to the constant voltage to constant current module, and instruct the constant voltage to constant current module to convert the constant voltage into a constant current and output it to each input electrode; and when the voltage value received by the microcontroller from the on-off feedback circuit is less than the feedback voltage threshold and the duration of being continuously less than the feedback voltage threshold is greater than the set sleep time, the microcontroller instructs the low voltage boost feedback control module to shut down.

[0006] Furthermore, the low-voltage boost feedback control module described in the present invention includes a switching circuit, an LC boost circuit and a voltage feedback circuit; the first input end of the switching circuit is connected to the power supply module, the second input end of the switching circuit is connected to the microcontroller, the output end of the switching circuit is connected to the first input end of the LC boost circuit, and the second input end of the LC boost circuit is connected to the microcontroller; the output end of the LC boost circuit is respectively connected to the input end of the voltage feedback circuit and the input end of the constant voltage to constant current module, the first output end of the voltage feedback circuit is connected to the microcontroller, and the second output end of the voltage feedback circuit is connected to the input end of the constant voltage to constant current module.

[0007] Furthermore, the voltage feedback circuit of the present invention includes a TVS transient suppression diode, a ninth resistor, a thirteenth resistor, an eleventh resistor and a fourth capacitor; the input end of the TVS transient suppression diode is simultaneously connected to the output end of the LC boost circuit and the input end of the constant voltage to constant current module; the output end of the TVS transient suppression diode is connected to one end of the ninth resistor, the other end of the ninth resistor is respectively electrically connected to one end of the eleventh resistor, one end of the thirteenth resistor, and the positive electrode of the fourth capacitor, the other end of the eleventh resistor is connected to the microcontroller, and the other end of the thirteenth resistor and the negative electrode of the fourth capacitor are grounded respectively.

[0008] Furthermore, the on-off feedback circuit of the present invention includes a first resistor and a third resistor, one end of the first resistor and one end of the third resistor are respectively connected to each output electrode, the other end of the first resistor is connected to the microcontroller, and the other end of the third resistor is grounded; the on-off feedback circuit feeds back the voltage value of the third resistor to the microcontroller through the first resistor, when the voltage value of the third resistor received by the microcontroller from the on-off feedback circuit is less than the feedback voltage threshold and continues to be less than the feedback voltage threshold for a time greater than the set sleep time, the microcontroller receives the feedback and instructs the low-voltage boost feedback control module to shut down.

[0009] Furthermore, the microcontroller of the present invention is connected to an external PC.

[0010] Furthermore, in the boosting process of the low voltage boosting feedback control module of the present invention, if the microcontroller determines that the current voltage value of the low voltage boosting feedback control module collected by it is greater than or equal to the preset high voltage, the microcontroller sends the charging time of the current boosting of the low voltage boosting feedback control module to the low voltage boosting feedback control module as the charging time for the next boosting; if the microcontroller determines that the current voltage value of the low voltage boosting feedback control module collected by it is less than the preset high voltage, the microcontroller calculates the charging time required for the next boosting of the low voltage boosting feedback control module according to the following formula (1) and sends it to the low voltage boosting feedback control module:

[0011] Tn=Tl-k(Un-Us) (1)

[0012] In formula (1), Tn is the charging time required for the next boost by the low voltage boost feedback control module, Tl is the charging time for the current boost by the low voltage boost feedback control module, k represents the coefficient of variation of the single charging time, k=0.25ms / V, Un is the current voltage value of the low voltage boost feedback control module, and Us is the reference value of the preset high voltage.

[0013] Furthermore, the lower limit of the preset high voltage in the present invention is greater than the breakdown voltage of the TVS transient suppression diode.

[0014] Furthermore, the present invention sets a working status control button in the power module, one end of the working status control button is respectively connected to the positive pole of the power module and the microcontroller, and the other end of the working status control button is connected to the negative pole of the power module. When the working status control button is pressed, the microcontroller can receive and calculate the duration signal of the working status control button being pressed; in the shutdown state, if the working status control button is long pressed, the microcontroller sends an instruction to the switch circuit to change the current state of the stimulator to the working state; in the working state, if the working status control button is long pressed, the microcontroller sends an instruction to the switch circuit to change the current state of the stimulator to the shutdown state; in the working state, if the working status control button is short pressed, then each time the working status control button is short pressed, the microcontroller increases the sleep time of the stimulator in the working state by once based on the current value. When the sleep time reaches the set upper limit value, if the working status control button is short pressed again, the sleep time is reset to the set lower limit value.

[0015] Furthermore, in the present invention, the duration of long pressing the working state control button is 3 to 5 seconds, and the duration of short pressing the working state control button once is greater than 0 and less than or equal to 1 second.

[0016] Furthermore, when the present invention is in working state, each time the working state control button is short pressed once, the sleep time of the stimulator increases by 1s based on the current value; when the current value of the sleep time reaches 7s, if the working state control button is short pressed once again, the sleep time is reset to 1s.

[0017] Compared with the prior art, the beneficial effects of the present invention are: (1) the current voltage can be detected and fed back in real time through the low-voltage boost-high-voltage feedback control module to prevent the voltage from being boosted too high and damaging related components, while shortening the charging time, thereby greatly reducing the power consumption of the stimulator in the working state; (2) when the stimulator is in the working state, when the electrode is disconnected or falls off, the microcontroller can promptly monitor the amplitude or frequency of the stimulation current abnormality through the on-off feedback circuit set at the output electrode end, and instruct the low-voltage boost-high-voltage feedback control module to shut down, so that the stimulator of the present invention has extremely low power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural principle block diagram of the present invention;

[0019] Figure 2 It is a principle block diagram of the low-pressure boosting feedback control module of the present invention;

[0020] Figure 3 A circuit diagram of an embodiment of a voltage feedback circuit of the present invention;

[0021] Figure 4 It is a schematic diagram of a constant current stimulation signal output by a constant voltage to constant current module during a stimulation process of the present invention;

[0022] Figure 5 It is a charging schematic diagram of the low-voltage boosting feedback control module during a stimulation process of the present invention;

[0023] Figure 6 It is a schematic diagram of a boost voltage signal of a low voltage boost voltage feedback control module during a stimulation process of the present invention;

[0024] Figure 7 A circuit diagram of an embodiment of an on-off feedback circuit of the present invention;

[0025] Figure 8 It is a schematic diagram of power consumption signal of the stimulator of the present invention during operation;

[0026] In the figure, 2. power supply module, 3. low voltage to high voltage feedback control module, 31. switch circuit, 32. LC boost circuit, 33. voltage feedback circuit, 4. constant voltage to constant current module, 5. electrode patch, 51. input electrode, 52. output electrode, 53, 54. electrode connecting ring, 6. on-off feedback circuit, 7. microcontroller. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the accompanying drawings.

[0028] like Figure 1As shown, the stimulator of the present invention mainly includes a power module 2, a low-voltage boosting feedback control module 3, a constant voltage to constant current module 4, an on-off feedback circuit 6, a microcontroller 7 and N pairs of electrodes, where N is an integer greater than or equal to 1. Each pair of electrodes includes an input electrode 51 and an output electrode 52, each input electrode 51 is electrically connected to the output end of the constant voltage to constant current module 4, each output electrode 52 is electrically connected to the input end of the on-off feedback circuit 6, and the output end of the low-voltage boosting feedback control module 3 is connected to the input end of the constant voltage to constant current module 4. The power module 2 is connected to the low-voltage boosting feedback control module 3 and the microcontroller 7 respectively; the low-voltage boosting feedback control module 3, the constant voltage to constant current module 4, and the on-off feedback circuit 6 are connected to the microcontroller 7 respectively. When using the stimulator of the present invention, the input electrode 51 and the output electrode 52 of each pair of electrodes are closely fitted to the neuromuscular tissue.

[0029] When the stimulator of the present invention is in working state, the microcontroller 7 can collect the current voltage of the low voltage boost feedback control module 3, and compare the current voltage with the preset high voltage: if the current voltage is less than the preset high voltage, the microcontroller 7 instructs the low voltage boost feedback control module 3 to increase the voltage to the preset high voltage, and then outputs the high voltage to the constant voltage to constant current module 4, drives the constant voltage to constant current module 4 to generate a constant current and outputs it to the input electrode 51; if the current voltage of the low voltage boost feedback control module 3 is greater than or equal to the preset high voltage, the microcontroller 7 instructs the low voltage boost feedback control module 3 to output the current voltage as a high voltage power supply to the constant voltage to constant current module 4, and instructs the constant voltage to constant current module 4 to convert the constant voltage into a constant current and output it to the input electrode 51, and then, the constant current output by the constant voltage to constant current module 4 is output to the neuromuscular tissue where the input electrode 51 is located through the input electrode 51, and forms a closed current loop with the output electrode 52 and the on-off feedback circuit 6 connected to the output electrode 52. Thus, a stimulation can be completed by applying a constant current to the neuromuscular tissue between the input electrode 51 and the output electrode 52. The voltage source of the constant voltage to constant current module 4 of the stimulator of the present invention is set to match the impedance of the biological tissue using the stimulator. Since the impedance of the biological tissue is basically in the range of 2KΩ to 20MΩ, for this reason, the voltage source of the constant voltage to constant current module 4 of the stimulator is also usually set to 100v to 130v. If the impedance of the biological tissue changes, the voltage source setting of the constant voltage to constant current module 4 is also changed accordingly. In the present invention, the value interval of the preset high voltage is consistent with the voltage source of the constant voltage to constant current module 4, that is, if the voltage source of the constant voltage to constant current module 4 is 100 to 130V, the preset high voltage can be taken in the range of 100 to 130V. In addition, when the voltage value received by the microcontroller 7 from the on-off feedback circuit 6 is less than the feedback voltage threshold and the duration of being continuously less than the feedback voltage threshold is greater than the set sleep time, the microcontroller 7 instructs the low voltage boost feedback control module 3 to shut down. In the present invention, the set sleep time can be set to 5 to 10 stimulation cycles.

[0030] like Figure 1 As shown, as an embodiment of the present invention, the stimulator may also be provided with a housing (not shown in the figure), the input electrodes 51 and 52 are placed outside the housing, and the power supply module 2, the low voltage boost feedback control module 3, the constant voltage to constant current module 4, the on-off feedback circuit 6 and the microcontroller 7 are placed on a circuit board inside the housing. Figure 1 In the embodiment shown, the stimulator is flat in overall appearance. The housing of the present invention can be made of plastic or silicone to protect the circuit board inside.

[0031] As a preferred embodiment of the present invention, an electrode patch 5 can be used, the electrode patch 5 is a flexible fabric, and two electrode connection rings 53 and 54 are embedded in the electrode patch 5, wherein the input electrode 51 is connected to the electrode connection ring 53 through a soft wire, and the output electrode 52 is connected to the electrode connection ring 54 through a soft wire, thereby connecting the input electrode 51 to the output end of the constant voltage to constant current module 4, and connecting the output electrode 52 to the input end of the on-off feedback circuit 6. The input electrode 51 and the output electrode 52 can use a body surface self-adhesive electrode sheet. This structural design can protect the circuit in the shell on the one hand, and the electrode patch 5 has good flexibility, which is convenient for the entire shell and the electrode patch 5 to fit the body surface stimulation site.

[0032] It should be noted that the relative position between the input electrode 51 and the output electrode 52 is not fixed and can be adjusted according to the position on the body surface where the muscle and nerve tissue needs to be stimulated. In addition, there can be more than two electrode patches 5, each electrode patch 5 is configured with a pair of electrodes, each pair of electrodes includes an input electrode 51 and an output electrode 52, each input electrode 51 is connected to the constant voltage to constant current module 4 through a separate circuit switch, and each output electrode 52 is connected to the on-off feedback circuit 6 through a separate circuit switch, so that each pair of electrodes is connected to the nerve and muscle tissue, the constant voltage to constant current module 4, and the on-off feedback circuit 6 to form a separate closed current loop, so as to stimulate the nerve and muscle tissue in multiple different parts.

[0033] like Figure 2 As shown, as a preferred embodiment of the present invention, the low voltage boost feedback control module includes a switch circuit 31, an LC boost circuit 32 and a voltage feedback circuit 33; the first input end of the switch circuit 31 is connected to the positive electrode of the power module 2, the second input end of the switch circuit 31 is connected to the microcontroller 7, the output end of the switch circuit 31 is connected to the first input end of the LC boost circuit 32, and the second input end of the LC boost circuit 32 is connected to the microcontroller 7; the output end of the LC boost circuit 32 is respectively connected to the input end of the voltage feedback circuit 33 and the input end of the constant voltage to constant current module 4; the first output end of the voltage feedback circuit 33 is connected to the microcontroller 7, and the second output end of the voltage feedback circuit 33 is connected to the input end of the constant voltage to constant current module 4. The voltage feedback circuit 33 is used to detect the voltage value after the LC boost circuit 32 is boosted, and the specific voltage value is fed back to the microcontroller 7 through the first output end of the voltage feedback circuit 33.

[0034] like Figure 3As shown, as a preferred embodiment of the present invention, the voltage feedback circuit 33 includes a TVS transient suppression diode D8, a ninth resistor R9, a thirteenth resistor R13, an eleventh resistor R11 and a fourth capacitor C4; the input end of the TVS transient suppression diode D8 serves as both the input end and the second output end of the voltage feedback circuit 33, and is simultaneously connected to the output end of the LC boost circuit 32 and the input end of the constant voltage to constant current module 4; the output end of the TVS transient suppression diode D8 is connected to one end of the ninth resistor R9, and the other end of the ninth resistor R9 is respectively electrically connected to one end of the eleventh resistor R11, one end of the thirteenth resistor R13, and the positive electrode of the fourth capacitor C4; the other end of the eleventh resistor R11 serves as the first output end of the voltage feedback circuit 33 and is connected to the microcontroller 7, and the other end of the thirteenth resistor R13 and the negative electrode of the fourth capacitor C4 are respectively grounded.

[0035] This embodiment realizes that during the stimulation of the stimulator, the low voltage boost feedback control module 3 boosts the low voltage to the preset high voltage in the shortest time. During the boost process of the low voltage boost feedback control module 3, the microcontroller 7 can shorten the charging time of the next boost by obtaining the charging time of the current boost and the high voltage value boosted, while avoiding excessive boost. Specifically, in a boosting process of the low-voltage boost feedback control module 3, starting from the boosting of the LC boost circuit 32, after the boosting, the voltage value at the input end of the voltage feedback circuit 33 is greater than the breakdown voltage of the TVS transient suppression diode D8, the input end of the voltage feedback circuit 33 is turned on, and the microcontroller 7 collects the current voltage value through the first output end of the voltage feedback circuit 33. Since the current voltage value at this time has not reached the preset high voltage, the microcontroller 7 instructs the low-voltage boost feedback control module 3 to continue boosting until the preset high voltage is reached, that is, the LC boost circuit 32 will continue to boost until the current voltage is greater than or equal to the preset high voltage, and the microcontroller 7 obtains the charging time of this boosting and the corresponding current voltage value (denoted as Un) when the boosting is terminated; further, the microcontroller 7 compares the current voltage value Un reached when the boosting is terminated with the reference value of the preset high voltage (denoted as Us). Since the impedance of biological tissue is basically in the range of 2KΩ to 20MΩ, the reference value Us of the preset high voltage of the present invention can be set in the range of 100V to 130V. Generally, the higher the impedance of biological tissue is, the larger the value of Us can be. For example, the value of Us can be set to 120V.

[0036] If the reference value Us of the preset high voltage is 120V, the range of the allowed change value △U of the preset high voltage can be 0 to 10V. The smaller the allowed change range of △U, the higher the voltage detection accuracy of the microcontroller 7 needs to be selected. On the contrary, if the allowed change range of △U is too large, it may cause excessive charging voltage during the boost process and damage components. As an embodiment of the present invention, the allowed change value of the preset high voltage can be set to 10V, that is, △U=10V. At this time, the detectable range of the value interval of the preset high voltage is 110V~130V. In addition, a TVS transient suppression diode D8 is used in the voltage feedback circuit 33. When selecting the model of the TVS transient suppression diode D8, it is necessary to select a TVS transient suppression diode with a breakdown voltage value lower than the lower limit of the preset high voltage value interval. Only when the low-voltage boost feedback control module 3 raises the current voltage to a value higher than the breakdown voltage of the TVS transient suppression diode D8, the voltage feedback circuit 3 starts to conduct, and at the same time, the boosted current voltage value is fed back to the microcontroller 7 through the eleventh resistor R11. For this reason, in this embodiment, the breakdown voltage of the TVS transient suppression diode D8 needs to be less than the lower limit of the preset high voltage value interval of 110V. As mentioned above, the current voltage Un of the LC boost circuit 32 needs to be fed back to the microcontroller 7 in real time. If the breakdown voltage value of the TVS transient suppression diode D8 is too small, the working time of the voltage feedback circuit 33 will be extended, resulting in increased energy consumption. For this reason, the breakdown voltage Ud value of the TVS transient suppression diode D8 can be selected as 100V in this embodiment.

[0037] In this example, the resistance value of resistor R9 can be selected to be 1MΩ, and the resistance value of R13 can be selected to be 10KΩ. According to the microcontroller 7, the reference value Us of the preset high voltage is set to 120V, and the model of the TVS diode is selected. For this purpose, the breakdown voltage Ud of the TVS transient suppression diode D8 is selected to be 100V. When the LC boost circuit 32 boosts the voltage and the voltage output to the input end of the voltage feedback circuit 33 is higher than 100v, D8 is broken down, the voltage feedback circuit 33 is turned on, and the voltage value of the voltage divider resistor R13 is fed back to the microcontroller 7. During the boost process of the LC boost circuit 32, the voltage feedback circuit 33 reads the voltage value Ud of R13 through the microcontroller 7. 13 , and calculate the current voltage value Un=U of the LC boost circuit 32 R13 ×(R13+R9) / R13+100, to realize the real-time feedback of the current voltage of the low voltage boosting feedback control module 3 during the boosting process.

[0038] In a stimulation cycle of the stimulator, it can be divided into a high power consumption stage of the boosting process of the low voltage boosting feedback control module 3, a constant current stimulation output by the constant voltage to constant current module 4, and a low power consumption stage in the standby state. In the high power consumption stage, the power consumption of the stimulator is the largest, and shortening the time occupied by this stage can effectively reduce the power consumption of the stimulator; in the low power consumption stage, the power supply of the low voltage boosting feedback control module 3 and the constant voltage to constant current module 4 is turned off by the microcontroller 7, effectively reducing the power consumption of the stimulator during non-task execution.

[0039] like Figure 4 As shown, the process of the stimulator completing a stimulation cycle can be divided into three processes: charging of the low voltage boosting feedback control module 3, output of constant current stimulation by the constant voltage to constant current module 4, and standby of the stimulator, corresponding to Figure 4 The time periods Tc, Tf and Tx in the stimulation cycle are T = Tc + Tf + Tx. Figure 5 and Figure 6 As shown, before the stimulator outputs stimulation each time, that is, in the Tc time period, the low voltage boost feedback control module 3 controls the transistor to be periodically turned on and off in Tc, and accumulates the energy stored in the inductor to the fourth capacitor C4 by repeated pulse charging, thereby gradually boosting the low voltage of the power supply to a high voltage, until the current voltage value is above the preset high voltage, and then the microcontroller 7 controls the constant voltage to constant current module 4 to output constant current stimulation to the input electrode 51. The working time Tc of the low voltage boost feedback control module 3 is related to the boost voltage value of the LC boost circuit 32. The longer the Tc time, the higher the boost voltage value of the LC boost circuit 32, but too high a voltage may damage components and waste power consumption.

[0040] As described above, during the boost process of the low-voltage to high-voltage feedback control module 3, the microcontroller 7, through the voltage feedback circuit 33, feeds back the charging time Tc and the current voltage value Un, and judges and calculates the difference between Un and the reference value Us of the preset high voltage. By adjusting the next charging time Tn, the next charging time Tn is made as short as possible, thereby shortening the task execution time. To this end, it is necessary to judge the difference between the current voltage Un after the low-voltage to high-voltage feedback control module 3 boosts and the reference value Us of the preset high voltage. The microcontroller 7 sets the value range of the preset high voltage, that is, the value of Us±△U is the value range of the preset high voltage. That is to say, by judging the relationship between the difference between Un and Us and △U, it is judged whether the current voltage value Un is within the value range of the preset high voltage. For example, the calculation method of the charging time is that the microcontroller 7 calculates the next charging time Tn according to the difference between the current voltage Un and Us after the previous boost, and then sends a command to the low-voltage to high-voltage feedback control module 3. According to the current voltage value Un after the previous boost collected by the microcontroller 7, the charging time Tn required for the next boost is calculated. If the microcontroller 7 collects and judges that the difference between the current voltage value Un and the reference value Us of the preset high voltage is less than or equal to △U, the microcontroller 7 sends the time command of this boost to the low-voltage to high-voltage feedback control module 3 again as the next charging time command, that is, if 丨Un-Us丨≤△U, then Tn=Tl; if the microcontroller 7 collects and judges that the difference between the current voltage value and the reference value of the preset high voltage is greater than △U, that is, 丨Un-Us丨>△U, the microcontroller 7 calculates the time required for the next boost according to the difference between the current voltage value and the reference value of the preset high voltage. In this embodiment, the calculation method of Tn is: Tn=Tl-k(Un-Us). Wherein, Tl is the charging time of the previous charge, k represents the single-charge time change coefficient, and k = 0.25ms / V. And the adjusted time command after calculation is sent to the low-voltage to high-voltage feedback control module 3, so that the low-voltage to high-voltage feedback control module 3 can be adjusted to the preset high voltage as soon as possible during the next boost.

[0041] The microcontroller 7 compares the relationship between the difference between the current voltage value and the reference value of the preset high voltage and △U. If the difference between Un and Us is much greater than △U, the charging time will increase or decrease by a large margin. If the difference between Un and Us is slightly greater than △U, the charging time will increase or decrease by a small margin. If the difference between Un and Us is less than or equal to △U, the charging time remains unchanged, ultimately making the working time of the LC boost circuit reach the preset high voltage the shortest.

[0042] For example, during a certain stimulation treatment process, the microcontroller 7 and the PC (such as Figure 1As shown in the figure, after the communication, Us is set to 120V, and the preset high voltage is set to a range △U of 10V different from the reference value Us of the preset high voltage. After the low voltage boost feedback control module 3 boosts the low voltage of the power supply to 100V, the TVS diode is broken down, and the microcontroller 7 collects the current voltage of the voltage feedback circuit and determines that the current voltage value is less than the preset high voltage. Furthermore, the microcontroller 7 calculates the time Tn required for the next boost based on the difference (20v) between the current voltage value (100v) and the reference value (120v) of the preset high voltage, and sends an instruction to the low voltage boost feedback control module 3, so that the current voltage is boosted to the preset high voltage in a short time. As shown in the figure, Figure 5 As shown, the initial value T0 of the charging time in the LC boost circuit is set to 90ms. At this time, the current voltage value Un is about 100v. The charging time for the next charge is calculated by the microcontroller 7 programmed instruction. Taking k=0.25ms / V, the charging time Tn for the next charge is: Tn=90-0.25(100-120), and finally Tc=90ms+95ms, which is about 185ms. Then the instruction that the current charging time Tc is 185ms is sent by the microcontroller 7 to the LC boost circuit as the charging time of the LC boost circuit in the next charging process.

[0043] As an embodiment of the present invention, Figure 1 As shown, the input end of the microcontroller 7 is connected to an external PC. The PC can send instructions to the microcontroller 7 to change the constant current stimulation intensity and frequency of the stimulator.

[0044] The PC inputs instructions to the microcontroller 7 to set the sleep time of the stimulator, which can be set within the range of 1s to 7s, and sets the reference value Us of the preset high voltage. The initial value T0 of the charging time in the LC boost circuit is set to 90ms through the input end of the microcontroller 7. The microcontroller 7 can input instructions from the PC and store them, and execute according to the stored instructions; or the PC controls the execution in real time, and the microcontroller 7 forwards the programmed instructions to the switch circuit, the LC boost circuit, the voltage feedback circuit, the constant voltage to constant current module and the on-off feedback circuit, so as to set the stimulation frequency according to the clinical treatment plan. As another embodiment of the present invention, the programmed instructions stored in the microcontroller 7 can also directly control the switch circuit, the LC boost circuit, the voltage feedback circuit, the constant voltage to constant current module and the on-off feedback circuit to achieve the preset stimulation frequency and stimulation intensity.

[0045] When the stimulator of the present invention is in normal working state, the constant current output by the constant voltage to constant current module 4 is output to the neuromuscular tissue where it is located through the input electrode 51, forming a closed loop in the neuromuscular tissue between the input electrode 51 and the output electrode 52, and applying current stimulation to complete a stimulation cycle. Therefore, the electrode patch 5 of the stimulator needs to fit tightly with the neuromuscular tissue; but during the operation of the stimulator, the electrode patch 5 may become loose or fall off, resulting in reduced conductivity or even disconnection of the current loop between the input electrode 51 and the output electrode 52. At this time, the stimulation current value passing through the neuromuscular tissue will become smaller or zero, and the normal stimulation treatment effect cannot be achieved. For this reason, an on-off feedback circuit 6 is provided at one end of the output electrode 52 of the stimulator. The voltage value U fed back by the on-off feedback circuit 6 is compared by the microcontroller 7 K and the time interval between two consecutive stimulations to determine whether the stimulator electrode patch is properly attached to the muscle tissue. K Less than the feedback voltage threshold U y , and the feedback voltage U K Continuously less than the feedback voltage threshold U y The duration is greater than the current set sleep time T y (T y When the number of stimulation cycles is set to 5-10, the electrode patch 5 of the stimulator may become loose or fall off. At this time, the microcontroller 7 instructs the low-voltage boost feedback control module 3 to be closed.

[0046] In this embodiment, the voltage of the third resistor R3 is fed back to the microcontroller 7 as the feedback voltage U in the on-off feedback circuit 6. K Specifically, Figure 7 As shown, the on-off feedback circuit 6 includes a first resistor R1 and a third resistor R3, the first resistor R1 and the third resistor R3 are connected to the output electrode 52, the other end of the first resistor R1 is connected to the microcontroller 7, and the other end of the third resistor R3 is connected to the negative electrode of the power supply; the on-off feedback circuit 6 feeds back the voltage value of the third resistor R3 to the microcontroller 7 through the first resistor R1, and the microcontroller 7 can receive the voltage value of the third resistor R3 from the on-off feedback circuit 6 when the voltage value received by the microcontroller 7 from the on-off feedback circuit 6 is less than the feedback voltage threshold U y And it is continuously less than the feedback voltage threshold U y The time is greater than the current set sleep time T y (5 to 10 stimulation cycles), the microcontroller 7 receives the feedback and instructs the switch circuit 31 to turn off. At this time, the stimulator is in a low power consumption state.

[0047] Based on this, the microcontroller 7 needs to detect the voltage value Uk across the third resistor R3 in the on-off feedback circuit 6. In this embodiment, according to the performance test standard of the electrode impedance for nerve and muscle stimulators, the current limit of the stimulation electrode should be less than 100mA, the general empirical value is 15-30mA, and the stimulation frequency is about 1-100Hz, that is, the stimulation period is 0.01s-1s. Figure 7 The circuit diagram shown in FIG. 1 shows that the electrode patch 5 of the stimulator is in normal use and the feedback voltage U K The value is equal to the voltage value of the third resistor R3 (i.e. U K =Ic×R3, where Ic represents the stimulation current and R3 represents the resistance value of the third resistor R3). In this embodiment, the resistance value of the third resistor R3 is selected to be 51Ω. Then, in the normal stimulation state, the feedback voltage U K The value is approximately 0.76 to 1.53.

[0048] Set the feedback voltage threshold Uy through the PC. Uy should be smaller than the feedback voltage Uy under normal stimulation. K The smaller the feedback voltage threshold Uy is, the higher the voltage detection accuracy of the microcontroller 7 is required; the larger the feedback voltage threshold Uy is, the higher the requirement for the tightness of the electrode patch in the stimulator and the neuromuscular tissue is. y When the voltage U is greater than one stimulation cycle of the stimulator, the microcontroller 7 can avoid the feedback voltage U received by the on-off feedback circuit 6 due to factors such as muscle tissue activity and short-term voltage drop of the electrode patch. K Is it actually less than the feedback voltage threshold U y In the present invention, the sleep time T is set y As an embodiment of the present invention, the stimulation current Ic output to the neuromuscular tissue by the constant voltage to constant current module is 30mA, U K The value of is 1.53V, the feedback voltage threshold Uy of the stimulator is set to 0.3V, and the sleep time Ty is set to 5s. K If U K Less than 0.3V, and U K If the duration of less than 0.3V is greater than 5s, the microcontroller 7 determines that the electrode patch 5 of the current stimulator is in a detached state, and sends a closing instruction to the switch circuit 31. The stimulator no longer enters the next stimulation cycle, and the stimulator is adjusted to a low power consumption state.

[0049] In this embodiment, the microcontroller 7 selects an STM32 chip with a low power consumption mode and selects the Stop working mode of the chip as the working mode of the microcontroller in the low power consumption state of the stimulator. In this mode, the power consumption of the microcontroller is about 1 μA. Figure 8 As shown, during one stimulation process, during the pulse charging time of the LC boost circuit 32, that is, during the Tc time period, the stimulator is in a high power consumption state; during the rest of the time, that is, during the Tf and Tx time periods, the microcontroller turns off the switch circuit 31, that is, in one stimulation cycle, the Tc segment is in a high power consumption state, and the Tf and Tx segments are in a low power consumption state.

[0050] like Figure 4 , 5 and Figure 6 As shown, in this embodiment, the LC boost circuit 32 boosts to a stable voltage value of 130V, and the stable charging time Tn is about 180ms. The microcontroller 7 is set by the PC so that the microcontroller 7 outputs a stimulation pulse every 1s after the stimulator is turned on, that is, T=1s. In a stimulation cycle, the stimulator is in a high power consumption state within about 180ms (stimulation pulse width Tf<1ms, stimulation output time is negligible), and the remaining 820ms are in a low power consumption state. In this embodiment, in the low power consumption state, the actual measured value of the power consumption of the stimulator is 0.9μA, and the stimulator is in a high power consumption state for only about 180ms. The estimated power consumption of the stimulator is about 0.58mA, and the power consumption of the stimulator is about 0.1mA in a working cycle of 1s. As an embodiment of the present invention, when the stimulator of the present invention is used for treatment, a lithium battery is fixedly installed inside the power module so that the stimulator is autonomously powered by an internal power supply. A working state control button can be set in the power module, one end of the working state control button is respectively connected to the positive electrode of the power module and the microcontroller 7, and the other end of the working state control button is connected to the negative electrode of the power module. When the working state control button is pressed, the microcontroller 7 can receive and calculate the duration signal of the pressing of the working state control button.

[0051] As an embodiment of the present invention, in the off state, if the working state control button is pressed for one time (such as 3 to 5 seconds), the microcontroller sends an instruction to the switch circuit 31 to change the current state of the stimulator to the working state; in the working state, if the working state control button is pressed for one time, the microcontroller 7 sends an instruction to the switch circuit 31 to change the current state of the stimulator to the off state.

[0052] In the working state, if the working state control button is short pressed, each time the working state control button is short pressed (such as the duration of a short press is greater than 0 and less than or equal to 1s), the microcontroller 7 instructs the switch circuit 31 to increase the sleep time of the stimulator in the working state once based on the current value (such as the increase time is 1s). When the sleep time has reached the set upper limit value (such as 7s), if the working state control button is short pressed once again, the sleep time is reset to the set lower limit value (such as 1s). After that, each time the working state control button is short pressed once, the microcontroller 7 instructs the switch circuit 31 to increase the sleep time of the stimulator in the working state once based on the current value (such as 1s); once it increases to the set upper limit value (such as 7s), if the working state control button is short pressed once again, the sleep time will be reset to the set lower limit value (1s), and so on.

Claims

1. A low-power neuromuscular stimulator, characterized in that: It includes a power supply module, a low-voltage boosting feedback control module, a constant voltage to constant current module, an on-off feedback circuit, a microcontroller and N pairs of electrodes, where N is an integer greater than or equal to 1; each pair of electrodes includes an input electrode and an output electrode, each input electrode is electrically connected to the output end of the constant voltage to constant current module, and each output electrode is electrically connected to the input end of the on-off feedback circuit; the output end of the low-voltage boosting feedback control module is connected to the input end of the constant voltage to constant current module; the power supply module is connected to the low-voltage boosting feedback control module and the microcontroller respectively; the low-voltage boosting feedback control module, the constant voltage to constant current module, and the on-off feedback circuit are connected to the microcontroller respectively; the microcontroller can instruct the low-voltage boosting feedback control module to increase the voltage to a preset high voltage and then output it to the constant voltage to constant current module, and instruct the constant voltage to constant current module to convert the constant voltage into a constant current and output it to each input electrode; and when the voltage value received by the microcontroller from the on-off feedback circuit is less than the feedback voltage threshold and the duration of being continuously less than the feedback voltage threshold is greater than the set sleep time, the microcontroller instructs the low-voltage boosting feedback control module to shut down; During the voltage boosting process of the low voltage boosting feedback control module, if the microcontroller determines that the current voltage value of the low voltage boosting feedback control module collected by the microcontroller is greater than or equal to the preset high voltage, the microcontroller sends the charging time of the current voltage boosting of the low voltage boosting feedback control module to the low voltage boosting feedback control module as the charging time for the next voltage boosting; if the microcontroller determines that the current voltage value of the low voltage boosting feedback control module collected by the microcontroller is less than the preset high voltage, the microcontroller calculates the charging time required for the next voltage boosting of the low voltage boosting feedback control module according to the following formula (1) and sends it to the low voltage boosting feedback control module: Tn=Tl-k(Un-Us) (1) In formula (1), Tn is the charging time required for the next boost by the low voltage boost feedback control module, Tl is the charging time for the current boost by the low voltage boost feedback control module, k represents the coefficient of variation of the single charging time, k=0.25ms / V, Un is the current voltage value of the low voltage boost feedback control module, and Us is the reference value of the preset high voltage.

2. The low-power neuromuscular stimulator according to claim 1, characterized in that: The low-voltage boosting feedback control module comprises a switch circuit (31), an LC boosting circuit (32) and a voltage feedback circuit (33); a first input end of the switch circuit (31) is connected to a power module (2), a second input end of the switch circuit (31) is connected to a microcontroller, an output end of the switch circuit (31) is connected to a first input end of the LC boosting circuit (32), and a second input end of the LC boosting circuit (32) is connected to the microcontroller; an output end of the LC boosting circuit (32) is respectively connected to an input end of a voltage feedback circuit (33) and an input end of a constant voltage to constant current module (4), a first output end of the voltage feedback circuit (33) is connected to the microcontroller, and a second output end of the voltage feedback circuit (33) is connected to an input end of the constant voltage to constant current module (4).

3. The low power consumption neuromuscular stimulator according to claim 2, characterized in that: The voltage feedback circuit (33) comprises a TVS transient suppression diode (D8), a ninth resistor (R9), a thirteenth resistor (R13), an eleventh resistor (R11) and a fourth capacitor (C4); the input end of the TVS transient suppression diode (D8) is simultaneously connected to the output end of the LC boost circuit (32) and the input end of the constant voltage to constant current module; the output end of the TVS transient suppression diode (D8) is connected to one end of the ninth resistor (R9), the other end of the ninth resistor (R9) is respectively electrically connected to one end of the eleventh resistor (R11), one end of the thirteenth resistor (R13) and the positive electrode of the fourth capacitor (C4), the other end of the eleventh resistor (R11) is connected to the microcontroller, and the other end of the thirteenth resistor (R13) and the negative electrode of the fourth capacitor (C4) are respectively grounded.

4. The low power consumption neuromuscular stimulator according to any one of claims 1 to 3, characterized in that: The on-off feedback circuit (6) comprises a first resistor (R1) and a third resistor (R3), one end of the first resistor (R1) and one end of the third resistor (R3) are respectively connected to each output electrode, the other end of the first resistor (R1) is connected to the microcontroller, and the other end of the third resistor (R3) is grounded; the on-off feedback circuit feeds back the voltage value of the third resistor (R3) to the microcontroller via the first resistor (R1); when the voltage value of the third resistor (R3) received by the microcontroller from the on-off feedback circuit (6) is less than a feedback voltage threshold and remains less than the feedback voltage threshold for a period greater than a set sleep time, the microcontroller receives the feedback and instructs the low-voltage boost feedback control module (3) to shut down.

5. The low power consumption neuromuscular stimulator according to any one of claims 1 to 3, characterized in that: The microcontroller is connected to an external PC.

6. The low power consumption neuromuscular stimulator according to claim 4, characterized in that: The microcontroller is connected to an external PC.

7. The low power consumption neuromuscular stimulator according to claim 3, characterized in that: The lower limit of the preset high voltage is greater than the breakdown voltage of the TVS transient voltage suppressor diode (D8).

8. The low-power neuromuscular stimulator according to claim 7, characterized in that: The on-off feedback circuit comprises a first resistor (R1) and a third resistor (R3), one end of the first resistor (R1) and one end of the third resistor (R3) are respectively connected to each output electrode, the other end of the first resistor (R1) is connected to the microcontroller, and the other end of the third resistor (R3) is grounded; the on-off feedback circuit feeds back the voltage value of the third resistor (R3) to the microcontroller through the first resistor (R1); when the voltage value of the third resistor (R3) received by the microcontroller from the on-off feedback circuit is less than a feedback voltage threshold and the time that it continues to be less than the feedback voltage threshold is greater than a set sleep time, the microcontroller receives the feedback and instructs the low voltage boost feedback control module to shut down.

9. The low-power neuromuscular stimulator according to claim 7 or 8, characterized in that: The microcontroller is connected to an external PC.

10. The low-power neuromuscular stimulator according to claim 2 or 3, characterized in that: A working state control button is arranged in the power module, one end of the working state control button is respectively connected to the positive pole of the power module and the microcontroller, and the other end of the working state control button is connected to the negative pole of the power module. When the working state control button is pressed, the microcontroller can receive and calculate the pressing time signal of the working state control button. In the shutdown state, if the working state control button is long pressed, the microcontroller sends a command to the switch circuit (31) to change the current state of the stimulator to the working state. In the working state, if the working state control button is long pressed, the microcontroller sends a command to the switch circuit (31) to change the current state of the stimulator to the shutdown state. In the working state, if the working state control button is short pressed, each time the working state control button is short pressed, the microcontroller increases the sleep time of the stimulator in the working state by one time based on the current value. When the sleep time reaches the set upper limit value, if the working state control button is short pressed again, the sleep time is reset to the set lower limit value.

11. The low-power neuromuscular stimulator according to claim 10, characterized in that: The on-off feedback circuit comprises a first resistor (R1) and a third resistor (R3), one end of the first resistor (R1) and one end of the third resistor (R3) are respectively connected to each output electrode, the other end of the first resistor (R1) is connected to the microcontroller, and the other end of the third resistor (R3) is grounded; the on-off feedback circuit feeds back the voltage value of the third resistor (R3) to the microcontroller through the first resistor (R1); when the voltage value of the third resistor (R3) received by the microcontroller from the on-off feedback circuit is less than a feedback voltage threshold and the time that it continues to be less than the feedback voltage threshold is greater than a set sleep time, the microcontroller receives the feedback and instructs the low voltage boost feedback control module to shut down.

12. The low-power neuromuscular stimulator according to claim 10, characterized in that: The microcontroller is connected to an external PC.

13. The low-power neuromuscular stimulator according to claim 11, characterized in that: The microcontroller is connected to an external PC.

14. The low-power neuromuscular stimulator according to claim 10, characterized in that: The duration of long pressing the working state control button is 3 to 5 seconds, and the duration of short pressing the working state control button once is greater than 0 and less than or equal to 1 second.

15. The low power consumption neuromuscular stimulator according to any one of claims 11 to 13, characterized in that: The duration of long pressing the working state control button is 3 to 5 seconds, and the duration of short pressing the working state control button once is greater than 0 and less than or equal to 1 second.

16. The low-power neuromuscular stimulator according to claim 10, characterized in that: In the working state, each time the working state control button is short pressed once, the sleep time of the stimulator increases by 1s based on the current value; when the current value of the sleep time reaches 7s, if the working state control button is short pressed once again, the sleep time is reset to 1s.

17. The low-power neuromuscular stimulator according to claim 15, characterized in that: In the working state, each time the working state control button is short pressed once, the sleep time of the stimulator increases by 1s based on the current value; when the current value of the sleep time reaches 7s, if the working state control button is short pressed once again, the sleep time is reset to 1s.

18. The low power consumption neuromuscular stimulator according to any one of claims 11 to 14, characterized in that: In the working state, each time the working state control button is short pressed once, the sleep time of the stimulator increases by 1s based on the current value; when the current value of the sleep time reaches 7s, if the working state control button is short pressed once again, the sleep time is reset to 1s.

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