A temperature control method for physiotherapy

Abstract

The application discloses a temperature control method for physiotherapy, comprising the following steps: S1, a preheating stage, when the body surface temperature is lower than a preset value, heating is started, and meanwhile, control parameters of a physiotherapy head are acquired, including a temperature rising slope, a temperature falling slope, a thermal lag time and a temperature change curve, and a change trend of the temperature rising slope of the body surface temperature is monitored, and the heating step is adjusted according to different change trends; S2, an approaching stage, when the body surface temperature reaches above the preset value, the body surface temperature is controlled in a steady state range through a closed-loop control method; S3, a steady state control stage, a heating mode is adjusted according to the range of the up-and-down fluctuation of the body surface temperature; and S4, a temperature protection stage, steps S2, S3 or S4 are repeated according to the body surface temperature until the physiotherapy is finished. Through the stage control, not only can the body surface temperature of a physiotherapy object be effectively prevented from overheating, but also the physiotherapy equipment can be prevented from being damaged due to severe temperature change, the safety protection effect is achieved for both people and equipment, meanwhile, energy can be saved, and the operation cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of radiofrequency thermotherapy control technology, and in particular to a method for temperature control in physiotherapy. Background Technology

[0002] Radiofrequency therapy devices emit high-frequency electromagnetic waves of a specific frequency, causing the skin or subcutaneous tissue to vibrate and rub at high speed, thereby achieving a precise heating effect. Existing radiofrequency therapy technologies can basically achieve intelligent real-time temperature control.

[0003] Chinese patent CN117899368B discloses a radiofrequency hyperthermia control system and method. The control method analyzes and judges the temperature of the physiotherapy device applied to the human body surface based on this temperature to determine whether to adjust the radiofrequency parameters. Simultaneously, it collects the device's real-time temperature, compares it with normal values, and implements corresponding adjustments. It also monitors the adjusted device surface temperature in real time, performing secondary analysis and adjustment, and issuing early warning alarms for abnormal situations. However, this method is passive and lacks predictability, adjusting only when the temperature deviates from its target range. This leads to a response delay, causing periodic fluctuations in temperature, making it difficult to maintain a stable temperature within the ideal range. A better approach would be to predict overheating trends based on the rate of temperature change, resulting in a more stable and controllable temperature.

[0004] Chinese patent CN114904140A discloses a physiotherapy device and its control method and system. This method can obtain the user's metabolic index based on real-time physiological data and match a corresponding physiotherapy strategy to the user based on the index's trend parameters over a certain period. However, this scheme only calculates the metabolic index difference and updates the strategy after a preset duration, without clearly defining a preset metabolic index and without monitoring the actual impact of electrical stimulation on the metabolic index. It is an open-loop control, which not only cannot correct ineffective strategies but also has low safety. Summary of the Invention

[0005] Radiofrequency therapy temperature control is a first-order inertial system characterized by "large lag," "constraints," and "high safety requirements." Traditional PID control is prone to overshoot due to lag, leading to overheating risks. Therefore, this invention employs a "staged composite control strategy," combining feedforward, feedback, and safety protection mechanisms. To address the problems of existing technologies, this invention provides a temperature control method for physiotherapy. The specific solution of this invention is as follows: A method for temperature control in physiotherapy includes the following steps: S1: Preheating stage. Heating begins when the body surface temperature is lower than the preset value. At the same time, the control parameters of the physiotherapy head are acquired, including the heating slope, cooling slope, thermal hysteresis time and temperature change curve. The trend of the heating slope of the body surface temperature is monitored, and the heating steps are adjusted according to different trends. S2: Approaching phase, when the body surface temperature reaches or exceeds the preset value, the body surface temperature is controlled within the steady state range through closed-loop control. S3: Steady-state control stage, adjusting the heating method according to the range of fluctuations in body surface temperature; S4: Temperature protection phase. Repeat steps S2, S3, or S4 according to the body surface temperature until the physiotherapy is over.

[0006] Preferably, in step S1, the method for obtaining control parameters is to mark key temperature measurement points in each movement mode of the physiotherapy head, establish a three-dimensional coordinate system, and represent the key temperature measurement points, the number of movements, and the temperature, respectively. For a certain key temperature measurement point: the rate of temperature rise between two adjacent movements is the temperature rise slope; the rate of temperature drop after heating stops is the temperature drop slope; and the time difference between the highest temperature and the time when heating is turned off is the thermal hysteresis time. The curve connecting the temperatures of the key temperature measurement points for a certain movement is the temperature change curve.

[0007] Preferably, the motion modes of the therapy head include linear motion and non-linear motion. In various motion modes, the motion speed of the therapy head may be the same or different, and the frequency emitted by the therapy head may be the same or different.

[0008] Preferably, the heating method in step S1 includes the following steps: S101: When the body surface temperature is lower than the preset value, start the initial power to perform open-loop heating; S102: If there is no change in body surface temperature, report an error; otherwise, continue open-loop heating. S103: If the heating or cooling slope does not correspond to the current motion mode, an error will be reported; otherwise, open-loop heating will continue. S104: If the heating slope is significantly lower than expected, increase the heating power step by step; otherwise, continue open-loop heating. S105: If the heating slope is too large, proceed to step S2 ahead of time; otherwise, continue with open-loop heating.

[0009] Preferably, the closed-loop control method in step S2 is an improved PI or a fuzzy PI.

[0010] Preferably, the closed-loop control method in step S2 employs a PI controller with integral limiting, or further employs a low-pass filter to perform low-pass filtering on the temperature signal.

[0011] Preferably, the closed-loop control method includes the following steps: S201: Set a temperature dead zone. When the body surface temperature reaches or exceeds a preset value, maintain the current power within the temperature dead zone. S202: Monitor the heating slope and adjust the power or dynamically update the PI parameters based on the changing trend of the heating slope.

[0012] Preferably, in step S3, adjusting the heating method includes the following steps: S301: If the body surface temperature is below the lower limit of the temperature dead zone, maintain minimum power; S302: If the body surface temperature reaches or exceeds the upper limit of the temperature dead zone, the output will be turned off; S303: If the body surface temperature reaches or exceeds the mandatory temperature limit, proceed to step S4.

[0013] Preferably, in step S4, the temperature protection stage involves stopping heating and forcibly delaying the time. After the forced delay ends, the body temperature is adjusted to proceed to step S1, step S2, or step S3 until the physiotherapy is completed. The forced delay time is not less than the thermal hysteresis time.

[0014] Preferably, the physiotherapy head includes a heating component and a temperature measuring component. The heating area of ​​the heating component on the body surface is annular, and the temperature measuring area of ​​the temperature measuring component on the body surface is located at the center of the annular ring.

[0015] The technical solution of this invention has the following beneficial effects: This invention, through phased control, can not only effectively prevent the body surface temperature of the physiotherapy subject from overheating, but also avoid damage to the physiotherapy equipment due to drastic temperature changes, thus providing safety protection for both people and equipment. At the same time, it can save energy and reduce operating costs. The temperature change curve can effectively predict the temperature change trend and eliminate external interference, which not only significantly improves the stability of temperature control, but also effectively reduces energy consumption. Attached Figure Description

[0016] Figure 1 This is an overall flowchart of the present invention; Figure 2 This is a schematic diagram of the heating area and temperature measuring area of ​​the physiotherapy head of the present invention; Figure 3 This describes the motion trajectory of the therapeutic head under linear motion mode in this invention. Figure 4 This describes the motion trajectory of the therapeutic head under a single zigzag motion mode according to the present invention. Figure 5 This describes the motion trajectory of the therapeutic head under the curve motion mode of the present invention. Figure 6 This describes the motion trajectory of the physiotherapy head under the M-shaped zigzag motion mode of the present invention. Figure 7 This is a temperature change curve of a certain movement under the M-shaped zigzag motion mode of the physiotherapy head of the present invention; Figure 8 This is a flowchart of step S1 of the present invention; Figure 9 This is a flowchart of step S2 of the present invention; Figure 10 This is a flowchart of step S3 of the present invention. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0018] Reference Figure 1 This invention provides a method for temperature control in physiotherapy, comprising the following steps: S1: Preheating stage. Heating begins when the body surface temperature is lower than the preset value. At the same time, the control parameters of the physiotherapy head are acquired, including the heating slope, cooling slope, thermal hysteresis time and temperature change curve. The trend of the heating slope of the body surface temperature is monitored, and the heating steps are adjusted according to different trends. S2: Approaching phase, when the body surface temperature reaches or exceeds the preset value, the body surface temperature is controlled within the steady state range through closed-loop control. S3: Steady-state control stage, adjusting the heating method according to the range of fluctuations in body surface temperature; S4: Temperature protection phase. Repeat steps S2, S3, or S4 according to the body surface temperature until the physiotherapy is over.

[0019] In step S1, the method for obtaining control parameters is to mark key temperature measurement points in each movement mode of the physiotherapy head, establish a three-dimensional coordinate system, and represent the key temperature measurement points, the number of movements, and the temperature, respectively. For a certain key temperature measurement point: the rate of temperature rise between two adjacent movements is the temperature rise slope; the rate of temperature drop after heating stops is the temperature drop slope; and the time difference between the highest temperature and the time when heating is turned off is the thermal hysteresis time. The curve connecting the temperatures of the key temperature measurement points for a certain movement is the temperature change curve. Example 1

[0020] The preheating phase includes preheating and acquiring control parameters, which can also be verified general parameters: 1. Test the temperature rise slope: With the motion mode and speed fixed, perform open-loop heating (e.g., 50% power) for a certain time (e.g., 20 seconds) and calculate the temperature rise slope; 2. Test the cooling slope: Stop heating (e.g., 20 seconds) and calculate the cooling slope; 3. Conduct multiple tests using different power levels to find the heating slope that best meets the requirements; 4. Test the thermal hysteresis time of the sensor: Calculate the difference between "heating off time" and "peak temperature time (sensor combined with human sensation)".

[0021] The therapy head includes a heating element and a temperature measuring element.

[0022] Reference Figure 2The heating area of ​​the heating component on the body surface is circular, and the temperature measuring area of ​​the temperature measuring component on the body surface is located at the center of the circular ring. The movement mode of the physiotherapy head includes linear movement and non-linear movement. In various movement modes, the movement speed of the physiotherapy head is the same or different, and the frequency emitted by the physiotherapy head is the same or different. Example 2

[0023] Reference Figures 3 to 6 These represent the trajectories of linear motion, simple polygonal motion, curvilinear motion, and M-shaped polygonal motion, respectively. The arrows in the diagram indicate the direction of motion. Figure 7 The image shows the temperature change curve corresponding to a certain motion trajectory under the M-shaped polygonal motion mode. Points 1-9 on the X-axis are the key temperature measurement points marked in this mode. The curve formed by the temperatures of these key points is the temperature change curve. Figure 6 and Figure 7 It can be seen that under this trajectory, the temperatures at key points 1, 3, 5, 6, 8, and 9 are relatively low, while the temperatures at intersection points 2, 4, and 7 are higher due to repeated heating, but overall, the temperature shows an upward trend (e.g., ...). Figure 7 As shown by the dashed line, with the increase in the number of movements, the temperature at each key temperature measurement point will rise to varying degrees. Based on this, the temperature change trend can be predicted, making the temperature more stable and controllable. It should be noted that this invention is not limited to... Figures 3 to 6 In the motion mode, the marked temperature measurement key points are 1~n, and the number of motions is 1~m.

[0024] The relationship between temperature change curves and frequency allows us to find the highest temperature value of a certain motion trajectory at a certain frequency, thereby eliminating temperature fluctuations caused by external factors and obtaining a more accurate temperature value.

[0025] Reference Figure 8 The heating method in step S1 includes the following steps: S101: When the body surface temperature is lower than the preset value, start the initial power to perform open-loop heating; S102: If there is no change in body surface temperature, report an error; otherwise, continue open-loop heating. S103: If the heating or cooling slope does not correspond to the current motion mode, an error will be reported; otherwise, open-loop heating will continue. S104: If the heating slope is significantly lower than expected, increase the heating power step by step; otherwise, continue open-loop heating. S105: If the heating slope is too large, proceed to step S2 ahead of time; otherwise, continue with open-loop heating.

[0026] The closed-loop control method in step S2 is an improved PI or fuzzy PI, which uses a PI controller with integral limiting. A low-pass filter can also be added to perform low-pass filtering on the temperature signal. Example 3

[0027] Preheating employs an open-loop plus dynamic feedforward approach: 1. Triggering condition: Body surface temperature < preset value (e.g., target temperature - 2℃); 2. Use the predicted results to set the initial power and perform open-loop heating; 3. Monitor the temperature rise rate: A. If the temperature does not change, an error will be reported; B. If the temperature changes randomly (does not conform to the correspondence between "temperature change curve - motion pattern"), an error will be reported; C. If the heating rate is significantly lower than expected (possibly due to strong airflow or high skin resistance), the power can be increased step by step (one level at a time, each time for no less than 5 seconds). D. If the temperature rises too quickly (approaching the risk of overshoot, which means increasing power across gears), proceed to step S2 ahead of schedule.

[0028] Reference Figure 9 The closed-loop control method includes the following steps: S201: Set a temperature dead zone. When the body surface temperature reaches or exceeds a preset value, maintain the current power within the temperature dead zone. S202: Monitor the heating slope and adjust the power or dynamically update the PI parameters based on the changing trend of the heating slope. Example 4

[0029] The approximation phase includes closed-loop feedback and disturbance rejection: 1. Triggering conditions: Body surface temperature ≥ preset value (e.g., target temperature - 2℃) or dT / dt is too high; 2. Employ a PI controller with integral limiting to primarily suppress overshoot: A. Proportional Term (P): Dominant Response; B. Integral term (I): Accumulates slowly, but with an upper limit (e.g., integral output ≤ 20%). C. Differential term (D): Used to predict trends, not used; 3. Set temperature dead zone (e.g., ±0.3℃): If there is no "Step S3", maintain the current power within the target temperature + dead zone to avoid frequent adjustments; otherwise, jump to "Step S3". 4. Disturbance suppression: Monitor the heating and cooling slopes. If there is a sudden drop (such as increased airflow), increase the power and maintain it for 5 seconds before resuming. 5. Adaptive PID parameters: The parameters of P and I are dynamically updated according to the heating and cooling slopes within a certain range (e.g., ≤ 20%).

[0030] Reference Figure 10 In step S3, adjusting the heating method includes the following steps: S301: If the body surface temperature is below the lower limit of the temperature dead zone, maintain minimum power; S302: If the body surface temperature reaches or exceeds the upper limit of the temperature dead zone, the output will be turned off; S303: If the body surface temperature reaches or exceeds the mandatory temperature limit, proceed to step S4. Example 5

[0031] Hysteresis control can be used during the steady-state control phase. 1. Triggering condition: The target temperature is reached and stabilized (within the temperature dead zone); 2. If the body surface temperature is less than the lower limit of the temperature dead zone (e.g., target temperature -0.5℃), the power equals the minimum sustaining power. 3. If the body surface temperature is greater than or equal to the upper limit of the temperature dead zone (e.g., target temperature + 0.5℃), turn off the output; 4. If the body surface temperature is greater than or equal to the upper limit of the forced temperature, proceed to step S4.

[0032] In step S4, the temperature protection phase involves stopping heating and forcibly delaying the time. After the forced delay ends, the body temperature is adjusted to proceed to step S1, step S2, or step S3 until the physiotherapy is completed. The forced delay time is not less than the thermal hysteresis time.

[0033] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made under the inventive concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included within the protection scope of the present invention.

Claims

1. A method for temperature control in physiotherapy, characterized in that, Includes the following steps: S1: Preheating stage. Heating begins when the body surface temperature is lower than the preset value. At the same time, the control parameters of the physiotherapy head are acquired, including the heating slope, cooling slope, thermal hysteresis time and temperature change curve. The trend of the heating slope of the body surface temperature is monitored, and the heating steps are adjusted according to different trends. S2: Approaching phase, when the body surface temperature reaches or exceeds the preset value, the body surface temperature is controlled within the steady state range through closed-loop control. S3: Steady-state control stage, adjusting the heating method according to the range of fluctuations in body surface temperature; S4: Temperature protection phase. Repeat steps S2, S3, or S4 according to the body surface temperature until the physiotherapy is over.

2. The temperature control method for physiotherapy according to claim 1, characterized in that, In step S1, the method for obtaining control parameters is to mark key temperature measurement points in each movement mode of the physiotherapy head, establish a three-dimensional coordinate system, and represent the key temperature measurement points, the number of movements, and the temperature, respectively. For a certain key temperature measurement point: the rate of temperature rise between two adjacent movements is the temperature rise slope; the rate of temperature drop after heating stops is the temperature drop slope; and the time difference between the highest temperature and the time when heating is turned off is the thermal hysteresis time. The curve connecting the temperatures of the key temperature measurement points for a certain movement is the temperature change curve.

3. The temperature control method for physiotherapy according to claim 2, characterized in that, The motion modes of the therapy head include linear motion and non-linear motion. Under various motion modes, the motion speed of the therapy head may be the same or different, and the frequency emitted by the therapy head may be the same or different.

4. The temperature control method for physiotherapy according to claim 1, characterized in that, The heating method in step S1 includes the following steps: S101: When the body surface temperature is lower than the preset value, start the initial power to perform open-loop heating; S102: If there is no change in body surface temperature, report an error; otherwise, continue open-loop heating. S103: If the heating or cooling slope does not correspond to the current motion mode, an error will be reported; otherwise, open-loop heating will continue. S104: If the heating slope is significantly lower than expected, increase the heating power step by step; otherwise, continue open-loop heating. S105: If the heating slope is too large, proceed to step S2 ahead of time; otherwise, continue with open-loop heating.

5. The temperature control method for physiotherapy according to claim 1, characterized in that, The closed-loop control method in step S2 is an improved PI or a fuzzy PI.

6. The temperature control method for physiotherapy according to claim 1, characterized in that, The closed-loop control method in step S2 uses a PI controller with integral limiting, or a low-pass filter to perform low-pass filtering on the temperature signal.

7. The temperature control method for physiotherapy according to claim 5 or 6, characterized in that, The closed-loop control method includes the following steps: S201: Set a temperature dead zone. When the body surface temperature reaches or exceeds a preset value, maintain the current power within the temperature dead zone. S202: Monitor the heating slope and adjust the power or dynamically update the PI parameters based on the changing trend of the heating slope.

8. The temperature control method for physiotherapy according to claim 1, characterized in that, In step S3, adjusting the heating method includes the following steps: S301: If the body surface temperature is below the lower limit of the temperature dead zone, maintain minimum power; S302: If the body surface temperature reaches or exceeds the upper limit of the temperature dead zone, the output will be turned off; S303: If the body surface temperature reaches or exceeds the mandatory temperature limit, proceed to step S4.

9. The temperature control method for physiotherapy according to claim 1, characterized in that, In step S4, the temperature protection phase involves stopping heating and forcibly delaying the time. After the forced delay ends, the body temperature is adjusted to proceed to step S1, step S2, or step S3 until the physiotherapy is completed. The forced delay time is not less than the thermal hysteresis time.

10. The temperature control method for physiotherapy according to claim 1, characterized in that, The therapy head includes a heating element and a temperature measuring element. The heating area of ​​the heating element on the body surface is circular, and the temperature measuring area of ​​the temperature measuring element on the body surface is located at the center of the circular ring.

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