Control method and device of electric ring saw and electric ring saw device

Abstract

The present invention discloses a control method, device and electric ring saw device for an electric ring saw. The control method includes: storing the collected current signal of the motor operation in a sliding window of length M to cache the current signal; preprocessing the current signal cached in the sliding window to remove low-frequency interference and high-frequency interference; extracting the mutation effect characteristics used to characterize the penetration of the saw teeth based on the preprocessed current signal; comparing the mutation effect characteristics with a preset threshold to determine whether the saw teeth have penetrated; and when it is determined that the saw teeth have penetrated, stopping the output of the current signal of the motor operation and the motor stops running; when it is determined that the saw teeth have not penetrated, continuing to execute the above steps. The control method of the electric ring saw mentioned above accurately determines whether the saw teeth have penetrated the bone by real-time monitoring of the current signal during the penetration process of the ring saw, thereby effectively improving the safety and accuracy of the surgical process.

Description

Technical Field

[0001] The present invention relates to the field of medical technology, and in particular to a control method and device for an electric ring saw and an electric ring saw device. Background Art

[0002] Electric ring saws are used to make holes in bone tissue. Compared with traditional sawtooth drilling methods, electric ring saws can make large holes at one time. After the hole is cut, the bone at the resection site is removed and then put back into the hole after the operation. This can reduce surgical trauma and help patients recover quickly.

[0003] Existing electric trepanators can only drill holes but lack closed-loop control. They offer no safety warnings or protections for whether the hole penetrates or injures the contralateral soft tissue. Most cases rely solely on the doctor's experience, making them unsafe. Summary of the Invention

[0004] Based on this, it is necessary to provide a control method and device for an electric ring saw and an electric ring saw device to improve safety, in order to address the problem that existing electric ring saws cannot stop after penetration and have poor safety.

[0005] A control method for an electric ring saw, for controlling the operation or stopping of the electric ring saw, wherein the front end of the electric ring saw is provided with a plurality of saw teeth spaced apart along a circumferential direction, the control method comprising:

[0006] S1: storing the collected current signal of the motor in a sliding window of length M to cache the current signal;

[0007] S2: preprocessing the current signal buffered in the sliding window to remove low-frequency interference and high-frequency interference;

[0008] S3: extracting a mutation effect feature for characterizing the sawtooth penetration based on the preprocessed current signal;

[0009] S4: comparing the mutation effect feature with a preset threshold to determine whether the sawtooth has penetrated; and

[0010] S5: When it is determined that the sawtooth has penetrated, the output of the current signal for the motor operation is stopped, and the motor stops running; when it is determined that the sawtooth has not penetrated, S1-S4 are continued to be executed.

[0011] In one embodiment, the process of extracting the mutation effect feature for characterizing the sawtooth penetration based on the preprocessed current signal includes:

[0012] Perform an M - point Fourier transform on the pre - processed current signal to convert the time - domain signal into a frequency - domain signal, and extract the modulus value X(f0) of the fundamental frequency f0 of the signal and the modulus values X(f1), X(f2),..., X(fn) of the multiple - frequency frequencies f1, f2,..., fn of the fundamental frequency f0.

[0013] In one embodiment, the process of comparing the mutation effect feature with a preset threshold to determine whether the sawtooth has penetrated includes:

[0014] Compare the modulus value X(f0) of the fundamental frequency f0, the modulus values X(f1), X(f2),..., X(fn) of the multiple - frequency frequencies with the preset thresholds thread0, thread1, thread2,..., threadn respectively;

[0015] If X(f0) < thread0 and X(f1) > thread1, or X(f2) > thread2, or X(fn) > threadn, then determine that the sawtooth has penetrated.

[0016] In one embodiment, the process of extracting the mutation effect feature used to characterize the penetration of the sawtooth based on the pre - processed current signal includes:

[0017] Extract the maximum value max1 of the pre - processed current signal, perform data differentiation on the pre - processed current signal, calculate the current change rate, and extract the maximum current change rate max2.

[0018] In one embodiment, the process of comparing the mutation effect feature with a preset threshold to determine whether the sawtooth has penetrated includes:

[0019] Compare the maximum value max1 of the current signal and the maximum current change rate max2 with I_thread and I_diff_thread respectively;

[0020] If max1 > I_thread and max2 > I_diff_thread, then determine that the sawtooth has penetrated.

[0021] In one embodiment, the motor is an AC motor, and the method further includes:

[0022] Collect the original current signal of the motor operation;

[0023] Convert the collected original current signal into a digital signal through a high - speed ADC chip.

[0024] In one embodiment, the motor is an AC brushless motor, and the original current signal collected in the step of collecting the original current signal of the motor is a current signal of any phase of the AC brushless motor.

[0025] In one embodiment, preprocessing the current signal buffered in the sliding window to remove low-frequency interference and high-frequency interference includes:

[0026] The DC component in the current signal is filtered out through the FIR high-pass filter to remove low-frequency interference;

[0027] The high-frequency noise in the current signal is filtered out by the FIR low-pass filter to remove high-frequency interference.

[0028] A control device for an electric ring saw, for controlling the operation or stopping of the electric ring saw, wherein the front end of the electric ring saw is provided with a plurality of saw teeth spaced apart in a circumferential direction, the control device comprising:

[0029] A data cache module is used to store the collected motor current signal in a sliding window of length M for cache processing;

[0030] a signal preprocessing module, configured to preprocess the current signal cached in the sliding window by the data cache module to remove low-frequency interference and high-frequency interference;

[0031] A feature extraction module, configured to extract a feature of a mutation effect representing the sawtooth penetration based on the current signal preprocessed by the signal preprocessing module;

[0032] a comparison module, configured to compare the mutation effect feature extracted by the feature extraction module with a preset threshold; and

[0033] A control signal output module is used to determine whether the saw teeth have penetrated according to the comparison result of the comparison module, and output the current signal of the motor operation or stop outputting the current signal of the motor operation; wherein,

[0034] When it is determined that the sawtooth penetrates, the output of the current signal of the motor is stopped and the motor stops running; when it is determined that the sawtooth does not penetrate, the caching, preprocessing and feature extraction of the current signal are continued until it is determined that the sawtooth penetrates.

[0035] An electric ring saw device includes an electric ring saw and a drive handle, the front end of the electric ring saw is provided with a plurality of saw teeth arranged at intervals along the circumferential direction, the drive handle includes a motor, a motor driver and a controller, the motor driver is connected to the motor and the controller, the controller includes a computer program, and when the computer program is executed by a processor, the steps of the method are implemented.

[0036] The above-mentioned electric ring saw control method, device and electric ring saw device accurately determine whether the saw teeth have penetrated the bone by real-time monitoring of the current signal during the ring saw penetration process, thereby effectively improving the safety and accuracy of the surgical process. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a cross-sectional view of an electric ring saw device in one embodiment of the present invention;

[0038] Figure 2 for Figure 1 A partial enlarged schematic diagram of point A in the middle;

[0039] Figure 3 for Figure 1 A block diagram of a drive handle of the electric trepanning device shown in ;

[0040] Figure 4 The present invention is a flowchart of a method for controlling an electric ring saw in one embodiment of the present invention.

[0041] Description of reference numerals:

[0042] 100. Electric ring saw;

[0043] 110. Ring saw housing;

[0044] 120, outer ring saw unit; 121, outer saw teeth;

[0045] 130. Inner ring saw unit; 131. Inner saw teeth;

[0046] 140. Transmission parts;

[0047] 200, driving handle; 210, handle shell; 220, motor; 230, motor driver; 240, ADC module; 250, controller; 251, data cache module; 252, signal preprocessing module; 253, feature extraction module; 254, comparison and judgment module; 255, control signal output module. DETAILED DESCRIPTION

[0048] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following is a clear and complete description of the specific embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the specific details described below are only some embodiments of the present invention, and the present invention can also be implemented in many other embodiments different from those described herein. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0049] In this document, when an element is referred to as being "fixed to" another element, it may be directly attached to the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The directional terms such as front, back, upper, and lower involved are defined based on the position of the components in the drawings and the positions of the components relative to each other, and are only for the clarity and convenience of expressing the technical solution. It should be understood that the use of the directional terms should not limit the scope of protection claimed in the present invention.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0051] like Figure 1 、 2 As shown, the electric ring saw device in one embodiment of the present invention includes an electric ring saw 100 and a driving handle 200. The front end of the electric ring saw 100 is provided with a plurality of saw teeth arranged at intervals along the circumferential direction, which are used to open holes in human bone tissue (such as the spine); the driving handle 200 is used to drive the electric ring saw 100 to work.

[0052] The electric ring saw 100 includes a ring saw housing 110, a ring saw body, and a transmission member 140. The rear end of the ring saw body is rotatably mounted within the front end of the ring saw housing 110. The front end of the ring saw body is provided with saw teeth. The transmission member 140 is rotatably mounted within the rear end of the ring saw housing 110. The rear end of the transmission member 140 is provided with a connection interface. The front end of the transmission member 140 is in transmission engagement with the rear end of the ring saw body. As an example, the ring saw body includes an inner ring saw unit 130 and an outer ring saw unit 120. The rear end of the outer ring saw unit 120 is rotatably mounted within the front end of the ring saw housing 110. The front end is provided with a plurality of outer saw teeth 121 arranged in a circumferential direction. The inner ring saw unit 130 is located within the outer ring saw unit 120 and is capable of rotation and axial movement relative to the outer ring saw unit 120. The front end of the inner ring saw unit 130 extends out of the outer ring saw unit 120 and is provided with a plurality of inner saw teeth 131 arranged in a circumferential direction. The inner serrations 131 and the outer serrations 121 are used to circumscribe bone tissue to penetrate it.

[0053] like Figure 1 、 3As shown, the driving handle 200 includes a handle housing 210 and a motor 220, a motor driver 230 and a control device 250 arranged in the handle housing 210, wherein the output end of the motor 220 is connected to the transmission member 140, and the motor driver 230 is connected to the motor 220 for controlling the operation of the motor 220 (i.e., running or stopping). The control device 250 is used to process the current signal of the motor operation, determine whether the saw teeth penetrate the bone, and stop sending the current signal to the motor driver 230 when penetrating the bone to stop the motor 220.

[0054] like Figure 3 As shown, the control device 250 in the embodiment of the present application includes a data cache module 251, a signal preprocessing module 252, a feature extraction module 253, a comparison and judgment module 254 and a control signal output module 255. The data cache module 251 is used to store the collected current signal of the motor operation in a sliding window of length M for cache processing; the signal preprocessing module 252 is used to preprocess the current signal cached in the sliding window by the data cache module 251 to remove low-frequency interference and high-frequency interference; the feature extraction module 253 is used to characterize the signal based on the signal preprocessed by the signal preprocessing module 252. The characteristics of the bone penetration mutation effect are extracted; the comparison module 254 is used to compare the mutation effect characteristics extracted by the feature extraction module 253 with a preset threshold; the control signal output module 255 is used to determine whether the sawtooth has penetrated according to the comparison result of the comparison module 254, and output the current signal of the motor operation or stop outputting the current signal of the motor operation; wherein, when it is determined that the sawtooth has penetrated, the output of the current signal of the motor operation is stopped, and the motor stops running; when it is determined that the sawtooth has not penetrated, the caching, preprocessing and feature extraction of the current signal are continued until it is determined that the sawtooth has penetrated.

[0055] In one embodiment, motor 220 is an AC motor, and drive handle 200 further includes an ADC (Analog-to-Digital Converter) module 240. ADC module 240 is configured to convert analog signals into digital signals. Furthermore, motor 220 is an AC brushless motor. ADC module 240 acquires the current signal of any phase of the AC brushless motor.

[0056] Figure 4 A flow chart of a control method for an electric ring saw 100 provided in an embodiment of the present invention is shown. The control method for the electric ring saw 100 is used to control the operation or stop of the electric ring saw. The control method includes:

[0057] S1: The collected motor current signal is stored in a sliding window of length M to cache the current signal. A sliding window is a data processing technique used to extract fixed-length data segments from continuous data for processing. The window size is fixed, and the data is updated each time the window is moved. The data cache is used to temporarily store data for subsequent processing. The purpose of the data cache is to store the collected current signal data in a fixed-length sliding window for real-time caching. This ensures the continuity and consistency of data processing and provides the latest valid data for subsequent processing.

[0058] S2: preprocessing the current signal buffered in the sliding window to remove low-frequency interference and high-frequency interference;

[0059] S3: extracting a mutation effect feature for characterizing the sawtooth penetration based on the preprocessed current signal;

[0060] S4: comparing the mutation effect feature with a preset threshold to determine whether the sawtooth has penetrated; and

[0061] When it is determined that the saw teeth penetrate, the output of the current signal for the motor operation is stopped, and the motor stops running; when it is determined that the saw teeth do not penetrate, S1-S4 are continued to be executed.

[0062] During bone drilling with the electric trephine 100, the current signal exhibits distinct characteristics at different stages. During steady drilling, the current signal remains relatively stable. During penetration, the current signal exhibits significant abrupt changes, resulting in significant differences in both time and frequency domains compared to the steady drilling process. The control method of the present invention utilizes these differences to identify bone penetration and implement emergency stop control, thereby effectively improving the safety and accuracy of the surgical procedure.

[0063] In one embodiment, the collected current signal of the motor is stored in a sliding window of length M to cache the current signal. Specifically, the length of M is an exponent of 2, which can be 1024 bytes, 2048 bytes, etc.

[0064] In one embodiment, the steps of preprocessing the current signal buffered in the sliding window to remove low-frequency interference and high-frequency interference are as follows:

[0065] (1) High-pass filtering: The FIR (Finite Impulse Response filter) high-pass filter is used to filter out the DC component (low-frequency component) in the current signal and remove low-frequency interference.

[0066] (2) Low-pass filtering: Use FIR low-pass filter to filter out high-frequency noise in the current signal and remove high-frequency interference.

[0067] By preprocessing the original current signal, the signal-to-noise ratio is improved, ensuring the accuracy of subsequent processing.

[0068] During steady bone drilling, the current signal is relatively stable. At the moment of penetration, due to the loss of resistance, the current signal undergoes a sudden change, with the rate of change increasing dramatically. Therefore, penetration can be determined by comparing the magnitude and rate of change of the current signal. Furthermore, experiments have shown that during steady bone drilling, only one of the outer teeth 121 and inner teeth 131 contacts bone tissue. That is, during a complete rotation cycle, only one tooth contacts tissue. In this case, the harmonic frequency generated by the contact between the teeth and tissue is the same as the fundamental frequency (the frequency of the main engine rotational speed). During penetration, two, three, or more teeth contact tissue, generating a pulse with each contact. When multiple teeth contact tissue, each contact causes a change in the current signal. Consequently, the current signal contains not only the fundamental frequency of the main engine rotational speed, but also harmonic frequencies that are multiples of it. These harmonic frequencies are integer multiples of the fundamental frequency. By analyzing these frequency components and their energy changes, it is possible to determine whether the teeth have penetrated the tissue.

[0069] In one embodiment, the specific steps of extracting the mutation effect feature for characterizing the sawtooth penetration based on the preprocessed current signal are as follows:

[0070] (1) Extract the maximum value: Extract the maximum value max1 of the preprocessed signal.

[0071] (2) Data differentiation: Differentiate the preprocessed current signal, calculate the current change rate, and extract the maximum current change rate (max2). Data differentiation is a method for calculating the signal change rate. By performing a differential operation on the signal, the signal change rate is obtained. The purpose of data differentiation is to calculate the change rate of the current signal and detect sudden changes in the current signal. The maximum current change rate (max2) is the maximum value of the current change rate within a certain time window, reflecting the sudden change characteristics of the current signal during the penetration process.

[0072] (3) Fourier transform: Perform M-point Fourier transform on the preprocessed signal to convert the time domain signal into a frequency domain signal, and extract the modulus X(f0) of the signal's fundamental frequency f0 and the modulus X(f1), X(f2), ..., X(fn) of the multiple frequencies f1, f2, ..., fn of the fundamental frequency f0.

[0073] The fundamental frequency f0 is the main frequency component in the signal, that is, the rotational speed frequency of the motor 220, which can be obtained by calculating the rotational speed of the motor 220. The multiple frequencies f1, f2, ..., fn are integer multiple frequency components of the fundamental frequency. The modulus value is the amplitude of the frequency component, representing the intensity of the frequency component.

[0074] Among the maximum value max1, the maximum current change rate max2, the modulus value X(f0) of the fundamental frequency f0, and the modulus values of the multiple frequencies f1, f2, ..., fn of the fundamental frequency f0, a single condition can be used as the basis for judging whether the sawtooth penetrates, or any two conditions can be combined as the basis for judging whether the sawtooth penetrates, or three conditions can be combined as the basis for judging whether the sawtooth penetrates.

[0075] In one embodiment, the specific steps for comparing the mutation effect feature with a preset threshold to determine whether the sawtooth has penetrated are as follows:

[0076] (1) Comparison of the maximum value current: Compare the maximum value max1 with the peak threshold value I_thread obtained from the look-up table. If max1 > I_thread, it means that the bone has been penetrated.

[0077] (2) Comparison of the maximum current change rate: Compare the maximum current change rate max2 with the current differential threshold value I_diff_thread obtained from the look-up table. If max2 > I_diff_thread, it means that the bone has been penetrated. I_diff_thread is an empirical value.

[0078] (3) Comparison of frequency components: Compare X(f0), X(f1), X(f2), ..., X(fn) with thread0, thread1, thread2, ..., threadn respectively; if X(f0) < thread0 and X(f1) > thread1, or X(f0) < thread0, X(f2) > thread2, ..., or X(f0) < thread0, X(fn) > threadn, it means that the bone has been penetrated. thread0, thread1, thread2, ..., threadn are empirical values.

[0079] I_thread, I_diff_thread, thread0, thread1, thread2, ..., threadn are empirical values, and these threshold values are obtained by analyzing and statistically processing a large amount of experimental data. The specific implementation method is as follows:

[0080] 1. Data acquisition:

[0081] A large amount of motor current signal data is collected in the actual operating environment, including the current signal of the ring saw during normal drilling, the current signal of the ring saw at the moment of penetrating the bone and after, and the current signal of the ring saw at different gears and different drilling speeds.

[0082] 2. Data preprocessing:

[0083] (1) Preprocess the collected current signal, including filtering out the DC component and high-frequency noise, and extracting the effective signal.

[0084] (2) Differentiate the current signal and calculate the current change rate.

[0085] (3) Perform Fourier transform on the current signal to extract the frequency component.

[0086] 3. Feature extraction:

[0087] (1) Maximum current: The maximum current value I_max in different states.

[0088] (2) Maximum current change rate: The maximum current change rate I_diff_max obtained by differentiation.

[0089] (3) Frequency component energy: the energy of the main engine speed frequency f3 and its multiplier frequency f4 after Fourier transform.

[0090] 4. Threshold setting:

[0091] (1) Setting I_thread: During normal drilling, record the peak current signal, I_max'. At the moment of bone penetration, the current signal experiences a significant sudden change. Statistically analyze this data and set the current peak threshold, I_thread. This threshold can be set to 1.3-1.6 times I_max', taking the maximum current peak value during normal drilling plus a safety margin.

[0092] (2) Setting I_diff_thread: Record the maximum value of the current change rate I_diff_max' under different conditions. At the moment of penetration, the current change rate will increase sharply. Statistically analyze this data and set the current change rate threshold I_diff_thread. You can take the maximum current change rate under normal conditions plus a safety margin. I_diff_thread can be 1.3-1.6 times I_diff_max'.

[0093] (4) Setting thread0, thread1, thread2, ..., threadn: Extract the modulus values ​​X(f0)', X(f1)', X(f2)', ..., X(fn)' of the frequency components f0, f1, f2, ..., fn through Fourier transform. Statistically analyze the energy changes of the frequency components during and after normal drilling and penetration. Thread0 can be set to the minimum energy value of the main engine speed frequency f0 under normal conditions minus a safety margin. Thread0 can be set to 0.3-0.6 times X(f0)'. Thread 1, thread 2, ..., thread n can be set to the maximum value of the modulus X(f0)', X(f1)', X(f2)', ..., X(fn)' of the multiplier frequency f0, f1, f2, ..., fn under normal conditions plus a safety margin. Thread 1 can be 1.3-1.6 times X(f1)', thread 2 can be 1.3-1.6 times X(f2)', ..., thread n can be 1.3-1.6 times X(fn)'.

[0094] 6. Experimental verification:

[0095] Verify whether the set threshold is reasonable in actual operation to ensure accurate judgment when penetrating the bone.

[0096] Based on the validation results, adjust the threshold to achieve the best effect.

[0097] Through the above steps and methods, the thresholds of I_thread, I_diff_thread, thread1, thread2, ..., threadn can be reasonably set to ensure accurate judgment when the trephine penetrates the bone.

[0098] S5. When it is determined that the sawtooth has penetrated, the output of the current signal for the motor operation is stopped, and the motor stops running; when it is determined that the sawtooth has not penetrated, S1-S4 are continued.

[0099] When the judgment condition is met, a stop signal is output to stop the motor and ensure safety. If the judgment condition is not met, data collection and processing will continue until the judgment condition is met. That is, the window slides according to the set step size, updating the M-point data cache, and the newly sampled data points are entered into the cache, while the old data points are removed.

[0100] By using the method of the present invention, the current signal during the penetration process of the ring saw can be monitored in real time, and whether the saw teeth have penetrated the bone can be accurately determined, thereby effectively improving the safety and accuracy of the surgical process.

[0101] In one embodiment, the motor is an AC motor, and the control method of the electric ring saw further includes:

[0102] S01: Collecting the raw current signal of the motor. While the electric ring saw is operating, the raw current signal of the motor is collected in real time. In another embodiment, the motor is an AC brushless motor, and the collected raw current signal is the current signal of any phase of the AC brushless motor. Because brushless motors lack contact between brushes and the commutator, they do not generate brush sparks during operation, thus avoiding electromagnetic interference. Therefore, the motor generates no interference current during operation, thereby avoiding misjudgments caused by interference current and improving the accuracy of the control method.

[0103] S02: The collected raw current signal is converted into a digital signal using a high-speed ADC chip. High-speed ADC chips have high sampling rates and high precision, and can accurately convert analog signals into digital signals in a short period of time, thus providing basic data for subsequent signal processing and motor control.

[0104] The above-described embodiments merely illustrate several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, and all such variations and improvements fall within the scope of protection of the present invention.

Claims

1. A control device for an electric ring saw, used to control the operation or stop of the electric ring saw, wherein the front end of the electric ring saw is provided with a plurality of saw teeth arranged at intervals along the circumferential direction, characterized in that: The control device includes: A data cache module for storing the collected current signal of the motor operation in a sliding window with a length of M for cache processing; A signal preprocessing module for preprocessing the current signal cached in the sliding window by the data cache module to remove low-frequency interference and high-frequency interference; A feature extraction module for performing M-point Fourier transform on the preprocessed current signal to convert the time-domain signal into a frequency-domain signal, and extracting the modulus value X(f0) of the fundamental frequency f0 of the signal and the modulus values X(f1), X(f2),..., X(fn) of the multiple frequencies f1, f2,..., fn of the fundamental frequency f0 as the mutation effect features characterizing the sawtooth penetration; A comparison module for respectively comparing the modulus value X(f0) of the fundamental frequency f0, the modulus values X(f1), X(f2),..., X(fn) of the multiple frequencies with preset thresholds thread0, thread1, thread2,..., threadn; and A control signal output module for determining that the sawtooth has penetrated and stopping outputting the current signal of the motor operation and the motor stops running when the comparison result of the comparison module is X(f0) < thread0 and X(f1) > thread1, or X(f2) > thread2, or X(fn) > threadn; when it is determined that the sawtooth has not penetrated, continue to perform caching, preprocessing and feature extraction of the current signal until it is determined that the sawtooth has penetrated.

2. The control device of the electric ring saw according to claim 1, characterized in that: The signal preprocessing module is specifically used for: [[ID= ​ 3. The control device of the electric ring saw according to claim 1, characterized in that: ​ 4. The control device of the electric ring saw according to claim 1, characterized in that: ​ ​ ​ ​ 5. An electric ring saw device, characterized in that: It comprises an electric ring saw and a driving handle, wherein the front end of the electric ring saw is provided with a plurality of saw teeth arranged at intervals along the circumferential direction, the driving handle comprises a motor, a motor driver and the control device of the electric ring saw as described in claims 1-4, and the motor driver is connected to the motor and the control device of the electric ring saw.

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