Skull drill device with drilling automatic stop function

Abstract

The utility model provides a skull drill device with a drilling automatic stop function. The skull drill device comprises a current acquisition module, a processing module, a motor driving module and a motor which is in driving connection with a skull drill bit, the current acquisition module is respectively connected to the motor and the processing module, and the current acquisition module is used for acquiring current flowing through the motor to obtain a feedback current signal; the processing module is connected to the motor driving module, and the processing module is used for sending a stop signal to the motor driving module when the feedback current signal reaches a preset threshold condition; the motor driving module is connected to the motor and used for receiving the stop signal and controlling the skull drill bit to stop rotating through the motor. The skull drill can acquire the current flowing through the motor through the current acquisition module so as to acquire the feedback current signal, and the skull drill is controlled to stop rotating according to the feedback current signal, so that automatic stop of drilling is realized.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a skull drill device with a self-stopping drilling function. Background Technology

[0002] Currently, the skull drill is a device used in neurosurgery to drill holes in the skull. To prevent the skull drill bit from damaging the meninges after penetrating the skull during drilling, existing skull drills generally achieve automatic stopping after drilling through a mechanical clutch. That is, when drilling through the skull, the drive shaft between the skull drill bit and the motor is disengaged, thereby stopping the skull drill bit from rotating.

[0003] However, due to processing errors, the quality and thickness of the patient's skull, etc., the mechanical clutch of the skull drill bit is often in a state of being about to disengage but not actually disengaged when drilling through, resulting in low safety. Therefore, how to better enable the skull drill device to automatically stop when the skull drill bit has penetrated through is an urgent problem to be solved. Utility Model Content

[0004] The main purpose of this utility model is to provide a skull drill device with a self-stop function when drilling through, in order to solve the existing technical problem of how to make the skull drill device stop automatically when the skull drill bit drills through.

[0005] To achieve the above objectives, this utility model proposes a skull drill device with a self-stop function after drilling through the skull. The skull drill device includes: a current acquisition module, a processing module, a motor drive module, and a motor connected to the skull drill bit.

[0006] The current acquisition module is connected to both the motor and the processing module. The current acquisition module is used to acquire the current flowing through the motor to obtain a feedback current signal.

[0007] The processing module is connected to the motor drive module, and the processing module is used to send a stop signal to the motor drive module when the feedback current signal reaches a preset threshold condition.

[0008] The motor drive module is connected to the motor, and the motor drive module is used to receive the stop signal and control the skull drill bit to stop rotating through the motor.

[0009] In one embodiment, the processing module includes: a judgment unit and a processing unit;

[0010] The judgment unit is connected to the current acquisition module and the processing unit respectively. The judgment unit is used to send a drilling signal to the processing unit when the current value corresponding to the feedback current signal is higher than the preset current threshold.

[0011] The processing unit is connected to the motor drive module, and the processing unit is used to receive the drilling signal and send a stop signal to the motor drive module.

[0012] In one embodiment, the determination unit includes: a comparison subunit and a switching subunit;

[0013] The comparison subunit is connected to the current acquisition module and the switch subunit respectively. The comparison subunit is used to send a comparison signal to the switch subunit when the current value corresponding to the feedback current signal is higher than a preset current threshold.

[0014] The switching subunit is connected to the processing unit, and the switching subunit is used to receive the comparison signal and send a drilling signal to the processing unit.

[0015] In one embodiment, the comparison subunit includes: a first resistor to a third resistor and a comparator;

[0016] The non-inverting input of the comparator is connected to the current acquisition module, the inverting input of the comparator is connected to the first end of the first resistor, the second end of the first resistor is connected to the second end of the second resistor and the first end of the third resistor, the first end of the second resistor is connected to the power supply, the second end of the third resistor is grounded, and the output of the comparator is connected to the switching subunit.

[0017] In one embodiment, the switching subunit includes: a switching transistor, a fourth resistor, and a relay;

[0018] The base of the switching transistor is connected to the output of the comparator, the emitter of the switching transistor is connected to the first end of the fourth resistor, the second end of the fourth resistor is grounded, the collector of the switching transistor is connected to the second end of the coil of the relay, the first end of the coil is connected to the power supply, the first end of the normally closed contact switch of the relay is connected to the power supply, and the second end of the normally closed contact switch is connected to the processing unit.

[0019] In one embodiment, the current acquisition module includes: a current sensor;

[0020] The first end of the current sensor is connected to the motor, and the second end of the current sensor is connected to the non-inverting input of the comparator.

[0021] In one embodiment, the skull drill device further includes: a differential module;

[0022] The differential module is connected to both the current acquisition module and the processing module. The differential module is used to differentially amplify the feedback current signal and transmit the differentially amplified feedback current signal to the processing module.

[0023] In one embodiment, the differential module includes: a differential operational amplifier, a first capacitor, a second capacitor, and a fifth to a tenth resistor;

[0024] The current acquisition module is connected to the first end of the fifth resistor. The second end of the fifth resistor is connected to the first end of the seventh resistor and the first input end of the differential operational amplifier. The ground end of the differential operational amplifier is grounded. The second input end of the differential operational amplifier is connected to the second end of the sixth resistor and the first end of the eighth resistor. The first end of the sixth resistor is grounded. The first power supply end of the differential operational amplifier is connected to the positive power supply and the second end of the first capacitor. The first end of the first capacitor is grounded. The second power supply end of the differential operational amplifier is connected to the negative power supply and the first end of the second capacitor. The second end of the second capacitor is grounded. The first output end of the differential operational amplifier is connected to the second end of the eighth resistor and the first end of the tenth resistor. The second end of the tenth resistor is connected to the processing module. The second output end of the differential operational amplifier is connected to the second end of the seventh resistor and the first end of the ninth resistor. The second end of the ninth resistor is connected to the processing module.

[0025] In one embodiment, the skull drill device further includes: a conversion module;

[0026] The conversion module is connected to the current acquisition module and the processing module respectively. The conversion module is used to perform analog-to-digital conversion on the feedback current signal and transmit the converted feedback current signal to the processing module.

[0027] In one embodiment, the skull drill device further includes: a filtering module;

[0028] The filtering module is connected to both the conversion module and the processing module. The filtering module is used to filter the converted feedback current signal and transmit the filtered feedback current signal to the processing module.

[0029] This invention proposes a skull drill device with an automatic stop function after drilling. The skull drill device includes: a current acquisition module, a processing module, a motor drive module, and a motor connected to the skull drill bit. The current acquisition module is connected to both the motor and the processing module, and is used to acquire the current flowing through the motor to obtain a feedback current signal. The processing module is connected to the motor drive module, and is used to send a stop signal to the motor drive module when the feedback current signal reaches a preset threshold condition. The motor drive module is connected to the motor, and is used to receive the stop signal and control the skull drill bit to stop rotating through the motor. Because the feedback current of the motor differs when the skull drill bit rotates through different bone layers, and the critical point of drilling penetration is the boundary between different bone layers, different feedback currents will occur when the skull drill bit is at the critical point. Therefore, this utility model can collect the current flowing through the motor through the current acquisition module to obtain the feedback current signal. When the processing module detects that the feedback current signal reaches the preset threshold condition, it can transmit the generated stop signal to the motor drive module. The motor drive module controls the skull drill bit to stop rotating through the motor, thereby realizing the automatic stop of drilling. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0031] Figure 1 This is a structural block diagram of the first embodiment of the skull drilling device with self-stopping drilling function proposed in this utility model.

[0032] Figure 2 The circuit diagram of the processing module in the first embodiment of the skull drill device with drilling self-stop function proposed in this utility model embodiment;

[0033] Figure 3 This is a structural block diagram of a second embodiment of the skull drilling device with self-stopping drilling function proposed in this utility model.

[0034] Figure 4 The circuit diagram of the differential module in the second embodiment of the skull drilling device with drilling self-stop function proposed in this utility model is shown.

[0035] Explanation of icon numbers:

[0036] label name label name 1 Current acquisition module 6 Differential module 2 Processing module 7 Conversion Module 211 Comparison subunit 8 Filtering module 212 Switching subunit R1~R10 First resistor to tenth resistor 22 Processing unit C1~C2 First capacitor to second capacitor 3 Motor drive module U Differential operational amplifier 4 Skull drill N comparator 5 Skull drill bit driver Q Switching transistor 51 motor KA1 coil 52 mechanical unit KA1-1 Normally closed contact switch

[0037] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0038] It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0039] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0040] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0041] Furthermore, the use of terms such as "first" and "second" in this utility model is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, the user should consider such a combination of technical solutions to be non-existent and not within the scope of protection claimed by this utility model.

[0042] It should be noted that currently, the skull drill device is a device used in neurosurgery to drill holes in the skull. In order to prevent the skull drill bit from damaging the meninges after penetrating the skull during drilling, existing skull drill devices generally achieve automatic stopping after drilling through a mechanical clutch. That is, when drilling through the skull, the drive shaft between the skull drill bit and the motor is controlled to separate, thereby stopping the skull drill bit from rotating.

[0043] However, due to processing errors, the quality and thickness of the patient's skull, etc., the mechanical clutch of the skull drill bit is often in a state of being about to disengage but not actually disengaged when drilling through, resulting in low safety. Therefore, how to better enable the skull drill device to automatically stop when the skull drill bit has penetrated through is an urgent problem to be solved.

[0044] Therefore, to address the aforementioned shortcomings, this embodiment provides a skull drill device with an automatic stop function during drilling. Since the feedback current of the motor varies as the skull drill bit rotates through different bone layers, and the critical point for drilling is the boundary between different bone layers, different feedback currents occur when the skull drill bit is at the critical point. Therefore, this invention uses a current acquisition module to collect the current flowing through the motor to obtain a feedback current signal. When the processing module detects that the feedback current signal reaches a preset threshold, it transmits the resulting stop signal to the motor drive module. The motor drive module then controls the skull drill bit to stop rotating via the motor, thus achieving automatic stop during drilling.

[0045] For ease of understanding, the following is combined with Figures 1 to 4 The present invention provides a detailed description of the skull drill device with a self-stopping drilling function provided in the embodiments of the present invention.

[0046] Reference Figure 1 , Figure 1 This is a structural block diagram of the first embodiment of the skull drilling device with self-stopping drilling function proposed in this utility model.

[0047] like Figure 1 As shown, in this embodiment, the skull drill device includes: a current acquisition module 1, a processing module 2, a motor drive module 3, and a motor 51 that drives the skull drill bit 4.

[0048] It is understood that the skull drilling device described in this embodiment can be used in scenarios where holes are drilled into the skull, and it can also be used in scenarios where other equipment drills through and then automatically stops; this embodiment does not limit this application. Figure 1 As shown, the motor 51 described above can be a motor 51 in the skull drill device used to drive the skull drill bit 4 to rotate. The motor 51 can be installed in the skull drill bit driver 5 of the skull drill device, and the skull drill bit 4 can be detachably connected to the skull drill bit driver 5. The skull drill bit driver 5 can include a mechanical unit 52 and the aforementioned motor 51. The mechanical unit 52 can be a part used to connect the motor 51 and the skull drill bit 4. The specific structure is not limited in this embodiment. The mechanical unit 52 can connect the motor 51 and the skull drill bit 4 to drive the skull drill bit 4 to rotate. The aforementioned motor 51 can be connected to the processing module 2 through the motor drive module 3.

[0049] The current acquisition module 1 is connected to the motor 51 and the processing module 2 respectively. The current acquisition module 1 is used to acquire the current flowing through the motor 51 to obtain a feedback current signal.

[0050] The processing module 2 is connected to the motor drive module 3. The processing module 2 is used to send a stop signal to the motor drive module 3 when the feedback current signal reaches a preset threshold condition.

[0051] The motor drive module 3 is connected to the motor 51. The motor drive module 3 is used to receive the stop signal and control the skull drill 4 to stop rotating through the motor 51.

[0052] It should be understood that, under normal use, the above-mentioned processing module 2 can output a drive signal to the motor drive module 3. The motor drive module 3 may contain a motor drive circuit. When the motor drive module 3 receives the drive signal, it can generate a drive current and transmit it to the motor 51 so that the motor 51 drives the skull drill bit 4 to rotate.

[0053] It should also be noted that the aforementioned current acquisition module 1 can be a module with a current acquisition function, such as a current sensor, etc., and this embodiment does not limit it. When the skull drill device is working, the current acquisition module 1 can acquire the feedback current flowing through the motor 51 in real time during operation and generate a feedback current signal to be transmitted to the processing module 2. The aforementioned feedback current can be the current in the working circuit of the motor 51 during operation.

[0054] The aforementioned processing module 2 may be a module containing components such as a Central Processing Unit (CPU). The aforementioned preset threshold condition may be a condition used to determine whether the skull drill bit 4 has penetrated through. In this embodiment, the aforementioned preset threshold condition may be a condition where the current value of the feedback current signal is higher than a preset current threshold. Of course, it may also be other conditions used to determine the feedback current reached when the skull drill bit 4 penetrates through, such as the slope of the current change of the feedback current, etc. This embodiment does not limit this.

[0055] In the specific implementation, when the skull drill is running, the motor drive module 3 transmits the drive current to the motor 51 for driving. The motor 51 then generates a feedback current. The current acquisition module 1 acquires the feedback current in real time to obtain the feedback current signal and transmits it to the processing module 2. The processing module 2 can then determine whether the current value of the feedback current signal reaches the preset threshold condition. If not, it means that the drill has not penetrated. The processing module 2 continues to output the drive signal to the motor drive module 3, and the motor drive module 3 continues to output the drive current. If the drill has penetrated, it means that the drill has penetrated. The processing module 2 generates a stop signal and transmits it to the motor drive module 3. When the motor drive module 3 receives the stop signal, it can stop outputting the drive current, and thus the motor 51 can stop rotating, and the skull drill bit 4 also stops.

[0056] As another implementation method, in order to stop the skull drill 4, in addition to the above-mentioned method of controlling the stop output of drive current to motor 51 through processing module 2, motor drive module 3 can also output a short-term reverse signal after receiving the stop signal to reverse motor 51, drive skull drill 4 to reverse to overcome inertia and stop rotation, thereby achieving an emergency stop more quickly.

[0057] Because the feedback current of the motor 51 of the skull drill bit 4 is different when it rotates in different bone layers, and the critical point of drilling is the junction between different bone layers, the phenomenon of different feedback current will occur when the skull drill bit 4 is at the critical point.

[0058] Therefore, based on the above principle, when the skull drill bit 4 drills through, the feedback current of the motor 51 will increase. In this embodiment, the current can be collected to obtain the feedback current signal. When the current value corresponding to the feedback current signal reaches the preset threshold condition, the generated stop signal can be transmitted to the motor drive module 3, so that the motor 51 drives the skull drill bit 4 to stop rotating, realizing the self-stopping function after drilling through.

[0059] Furthermore, in order to stop the motor drive module 3 from outputting drive current, refer to Figure 2 , Figure 2 This is a circuit diagram of the processing module 2 in the first embodiment of the skull drill device with self-stopping drilling function proposed in this utility model. Figure 2 As shown, in this embodiment, the above-mentioned processing module 2 includes: a judgment unit and a processing unit 22;

[0060] The judgment unit is connected to the current acquisition module 1 and the processing unit 22 respectively. The judgment unit is used to send a drilling signal to the processing unit 22 when the current value corresponding to the feedback current signal is higher than the preset current threshold.

[0061] The processing unit 22 is connected to the motor drive module 3. The processing unit 22 is used to receive the drilling signal and send a stop signal to the motor drive module 3.

[0062] It should be noted that the aforementioned judgment unit can be a unit used to determine whether the current value is higher than a preset current threshold, and may include components such as comparators. The aforementioned preset current threshold can be set according to actual conditions, and this embodiment does not impose any restrictions on it.

[0063] The aforementioned processing unit 22 may include components such as a CPU. One of the detection pins in the processing unit 22 can be connected to the judgment unit to detect changes in the pin's voltage level. Based on these changes, the processing unit can then control whether the motor drive module 3 outputs a drive current. Since the specific circuitry of the motor drive module 3 in this embodiment is identical to that in a traditional skull drill, and the processing unit 22's control of the motor drive module 3's output drive current based on voltage level changes can be achieved using existing technology, this embodiment will not elaborate further.

[0064] In a specific implementation, after receiving the feedback current signal, the judgment unit can determine the current value corresponding to the feedback current signal and compare the current value with the preset current threshold. If the current value is not higher than the preset current threshold, it indicates that the drill has not penetrated and the judgment unit does not output a drill penetration signal. The processing unit 22 continues to control the motor drive module 3 to output the feedback current. If the current value is higher than the preset current threshold, it indicates that the drill has penetrated and the judgment unit outputs a drill penetration signal to the processing unit 22. The processing unit 22 then outputs a stop signal to the motor drive module 3, and the motor drive module 3 stops generating drive current.

[0065] Furthermore, in order to achieve the comparison function, continue as follows Figure 2 As shown, the judgment unit includes: a comparison subunit 211 and a switch subunit 212;

[0066] The comparison subunit 211 is connected to the current acquisition module 1 and the switch subunit 212 respectively. The comparison subunit 211 is used to send a comparison signal to the switch subunit 212 when the current value corresponding to the feedback current signal is higher than the preset current threshold.

[0067] The switching subunit 212 is connected to the processing unit 22. The switching subunit 212 is used to receive the comparison signal and send the drilling signal to the processing unit 22.

[0068] It is understood that the comparison subunit 211 may include a comparator N, or it may be implemented using other components for comparison; this embodiment does not impose any limitations on this. The switching subunit 212 may be a unit for generating a drill-through signal and may include components such as switches.

[0069] In actual use, when the comparison subunit 211 receives the feedback current signal, it can compare the current value corresponding to the feedback current signal with the preset current threshold. When the current value is not higher than the preset current threshold, no comparison signal is output to the switch subunit 212, and the switch subunit 212 does not output a drilling signal. When the current is higher than the preset current threshold, a comparison signal is output to the switch subunit 212, and the switch subunit 212 outputs a drilling signal to the processing module 2.

[0070] Furthermore, in this embodiment, the comparison subunit 211 includes: a first resistor R1 to a third resistor R3 and a comparator N;

[0071] The non-inverting input terminal of the comparator N is connected to the current acquisition module 1, the inverting input terminal of the comparator N is connected to the first terminal of the first resistor R1, the second terminal of the first resistor R1 is connected to the second terminal of the second resistor R2 and the first terminal of the third resistor R3, the first terminal of the second resistor R2 is connected to the power supply, the second terminal of the third resistor R3 is grounded, and the output terminal of the comparator N is connected to the switching subunit 212.

[0072] It should be understood that the first resistor R1 to the third resistor R3, under the action of the power supply, can provide a reference signal to comparator N, and the current value corresponding to this reference signal can be the preset current threshold. The resistance values ​​of the first resistor R1 to the third resistor R3 and the voltage value of the power supply can be set according to actual conditions.

[0073] As another implementation, in order to facilitate the user to adjust the above-mentioned preset current threshold, the third resistor R3 can be replaced with an adjustable resistor in this embodiment. That is, the first end and the adjustment end of the adjustable resistor can be connected to the second end of the second resistor R2, and the second end of the adjustable resistor is grounded. Then, the user can change the current value of the reference signal and change the preset current threshold by adjusting the resistance value of the adjustable resistor.

[0074] In practical use, when the current value of the feedback current signal is higher than the preset current threshold, the output of comparator N can output a comparison signal; when the current value of the feedback current signal is not higher than the preset current threshold, the output of comparator N will not output a comparison signal.

[0075] Furthermore, in this embodiment, the switching subunit 212 includes: a switching transistor Q, a fourth resistor R4, and a relay;

[0076] The base of the switching transistor Q is connected to the output terminal of the comparator N. The emitter of the switching transistor Q is connected to the first terminal of the fourth resistor R4. The second terminal of the fourth resistor R4 is grounded. The collector of the switching transistor Q is connected to the second terminal of the coil KA1 of the relay. The first terminal of the coil KA1 is connected to the power supply. The first terminal of the normally closed contact switch KA1-1 of the relay is connected to the power supply. The second terminal of the normally closed contact switch KA1-1 is connected to the processing unit 22.

[0077] It should be understood that the aforementioned switching transistor Q can be an NPN transistor, and other switching transistors Q can also be used; this embodiment does not impose any limitations on this. The aforementioned relay can be a normally closed relay. In this embodiment, one pin on the processing unit 22 can be connected to the second terminal of the normally closed contact switch KA1-1. In practical use, when the switching transistor Q does not receive a comparison signal, the switching transistor Q remains open, the coil KA1 is not energized, the normally closed contact switch KA1-1 is closed, and the pin connected to the normally closed contact switch KA1-1 in the processing unit 22 remains at a high level. When the processing unit 22 detects the high level, it maintains the output of the drive current from the motor drive module 3 to the motor 51, and the motor 51 operates normally. When the switching transistor Q receives a comparison signal, the switching transistor Q turns on, the coil KA1 is energized, the normally closed contact switch KA1-1 opens, and the pin connected to the normally closed contact switch KA1-1 becomes low, thereby outputting a drilling signal to the processing unit 22. When the processing unit 22 detects the low level, it generates a stop signal to the motor drive module 3, the motor drive module 3 stops transmitting the drive current to the motor 51, and the motor 51 stops rotating, thus achieving automatic stop during drilling.

[0078] Furthermore, in order to facilitate current acquisition, in this embodiment, the current acquisition module 1 includes a current sensor;

[0079] The first end of the current sensor is connected to the motor 51, and the second end of the current sensor is connected to the positive input of the comparator N.

[0080] It should be noted that the aforementioned current sensor can be a resistive current sensor or a Hall-effect current sensor, or of course, other current sensors. This embodiment does not limit the types of current sensors used.

[0081] In a specific implementation, the feedback current flowing through the motor 51 can be collected by a current sensor, and the obtained feedback current signal is transmitted to the non-inverting input of the comparator N.

[0082] In this embodiment, the feedback current flowing through the motor 51 can be collected by the current acquisition module 1 to obtain the feedback current signal. When the processing module 2 detects that the feedback current signal reaches the preset threshold condition, it can transmit the generated stop signal to the motor drive module 3. The motor drive module 3 stops transmitting the feedback current to the motor 51, so that the motor 51 drives the skull drill bit 4 to stop rotating, thereby realizing the drilling self-stop.

[0083] Reference Figure 3 , Figure 3 This is a structural block diagram of the second embodiment of the skull drilling device with self-stopping drilling function proposed in this utility model.

[0084] Considering that when the processing module 2 determines whether the current value of the feedback current signal reaches the preset threshold condition, in order to improve signal quality, such as... Figure 3 As shown, in this embodiment, the skull drill device further includes: a differential module 6;

[0085] The differential module 6 is connected to the current acquisition module 1 and the processing module 2 respectively. The differential module 6 is used to differentially amplify the feedback current signal and transmit the differentially amplified feedback current signal to the processing module 2.

[0086] It should be noted that the differential module 6 mentioned above can be a module with a differential amplifier, or it can be a module with other components for implementing differential amplification. This embodiment does not limit this.

[0087] In actual use, after receiving the feedback current signal output by the current acquisition module 1, the differential module 6 can differentially amplify it and transmit the differentially amplified feedback current signal to the processing module 2. The processing module 2 then determines whether the current value of the feedback current signal reaches the preset threshold condition.

[0088] It should be emphasized that, based on the first embodiment described above, the differential module 6 in this embodiment can be specifically connected to the second end of the current sensor and to the non-inverting input of the comparator N, that is, the differentially amplified feedback current signal is transmitted to the non-inverting input of the comparator N.

[0089] Furthermore, referring to Figure 4 , Figure 4 This is a circuit diagram of the differential module 6 in the second embodiment of the skull drill device with self-stopping drilling function proposed in this utility model. Figure 4 As shown, in this embodiment, the differential module 6 includes: a differential operational amplifier U, a first capacitor C1, a second capacitor C2, and a fifth resistor R5 to a tenth resistor R10;

[0090] The current acquisition module 1 is connected to the first terminal of the fifth resistor R5, and the second terminal of the fifth resistor R5 is connected to the first terminal of the seventh resistor R7 and the first input terminal of the differential operational amplifier U (i.e., Figure 4 The eighth pin of the differential operational amplifier U is connected to the ground terminal of the differential operational amplifier U (i.e., Figure 4 The second pin of the differential operational amplifier U is grounded (i.e., Figure 4 The second input terminal of the differential operational amplifier U (i.e., AGND) Figure 4The first pin of the differential operational amplifier U is connected to the second terminal of the sixth resistor R6 and the first terminal of the eighth resistor R8, respectively. The first terminal of the sixth resistor R6 is grounded, and the first power supply terminal of the differential operational amplifier U (i.e., Figure 4 The third pin of the differential operational amplifier U) is connected to the positive power supply (i.e. Figure 4 The first terminal of the differential operational amplifier U is connected to the second terminal of the first capacitor C1 (+VCC) and the second terminal of the first capacitor C1 is grounded. Figure 4 The sixth pin of the differential operational amplifier U is connected to the negative power supply (i.e., Figure 4 The first terminal of the differential operational amplifier U is connected to the first terminal of the second capacitor C2 (i.e., VCC) and the second terminal of the second capacitor C2 is grounded. Figure 4 The fourth pin of the differential operational amplifier U is connected to the second terminal of the eighth resistor R8 and the first terminal of the tenth resistor R10, respectively. The second terminal of the tenth resistor R10 is connected to the processing module 2. The second output terminal of the differential operational amplifier U (i.e. Figure 4 The fifth pin of the differential operational amplifier U is connected to the second end of the seventh resistor R7 and the first end of the ninth resistor R9, respectively. The second end of the ninth resistor R9 is connected to the processing module 2.

[0091] It is understood that the aforementioned differential operational amplifier U can be a dual-output differential operational amplifier U. In actual use, after the current acquisition module 1 (specifically, the aforementioned current sensor) acquires the feedback current signal, it can transmit it to the differential operational amplifier U through the fifth resistor R5. After differentially amplifying the feedback current signal, the differential operational amplifier U can transmit it to the processing module 2 through the first output terminal and the second output terminal of the differential operational amplifier U. The processing module 2 then makes a judgment based on the differentially amplified feedback current signal.

[0092] It should be emphasized that, in this embodiment, the differential operational amplifier U can transmit the differential amplified signal to the non-inverting input of the comparator N in the processing unit 22. However, since the comparison function in this embodiment can also be directly implemented by the CPU, that is, the processing module 2 does not set a judgment unit, but only a processing unit 22. The processing unit 22 includes a CPU, so the differential amplified feedback current signal can be directly transmitted to the processing unit 22. A preset current threshold is set inside the processing unit 22. The processing unit 22 can judge whether the current value of the differential amplified feedback current signal is higher than the preset current value, or obtain the current value based on the differential amplified feedback current signal and then judge whether the current value is higher than the preset current threshold. If it is, a stop signal is generated to the motor drive module 3; otherwise, it is not generated. The above-mentioned drilling self-stop effect can also be achieved.

[0093] Furthermore, considering that directly judging whether the drill has penetrated through the current value may lead to poor accuracy, in this embodiment, based on the premise of not setting a judgment unit as described above, the processing module 2 in this embodiment may only set a processing unit 22, and the above-mentioned condition of reaching the preset threshold may be set to the current change slope of the feedback current signal being higher than the first preset slope threshold.

[0094] Alternatively, a Fourier transform can be performed on the feedback current signal to obtain the target spectrum, and the frequency change slope of the target spectrum is higher than the second preset slope threshold.

[0095] Alternatively, the mechanical unit 52 may include a clutch structure, which is used to separate the input of the skull drill bit 4 and the output of the motor 51 after drilling through the skull so that the motor 51 rotates under no-load; the current change slope of the feedback current signal is detected to be higher than a third preset slope threshold.

[0096] It should be noted that the slope of the current change in the aforementioned feedback current signal can be the slope of the current value of the feedback current signal at the current moment. Since the feedback current signal will change abruptly and increase during drilling, the aforementioned preset threshold condition can be set to whether it is higher than the first preset slope threshold. This first preset slope threshold can be set according to the actual situation, and this embodiment does not impose any restrictions on it. The processing unit 22 can determine the current value based on the differentially amplified feedback current signal. If the slope of the current value is not higher than the first preset slope threshold, it indicates that drilling has not occurred, and there is no need to stop. The processing unit 22 continues to control the motor drive module 3 to output the feedback current, and the motor 51 continues to rotate. If it is higher than the first preset slope threshold, it indicates that drilling is occurring, and the processing unit 22 outputs a stop signal to the motor drive module 3, which then controls the motor 51 to stop rotating.

[0097] It is important to emphasize that since the feedback current signal can also be used as a judgment criterion in the frequency domain, in this embodiment, after obtaining the differentially amplified feedback current signal, the processing unit 22 can perform a Fourier transform on the feedback current signal to convert it from the time domain to the frequency domain, obtain the target spectrum, and then determine the frequency change slope of the target spectrum at the current moment. This frequency change slope can be the slope of the frequency of the feedback current signal at the current moment. It is then determined whether the frequency change slope is higher than a second preset slope threshold. This second preset slope threshold can also be set according to the actual situation, and this embodiment does not impose any restrictions on it. If it is not higher than the second preset slope threshold, it indicates that the drilling has not penetrated, and there is no need to stop; the processing unit 22 continues to control the motor 51 to rotate. If it is higher than the second preset slope threshold, it indicates that the drilling is penetrating, and the motor 51 is controlled to stop rotating.

[0098] It should also be emphasized that when the processing unit 22 makes a judgment, it only needs to reach either of the two preset threshold conditions mentioned above to control the motor 51 to stop. That is, when the slope of the current change of the current value of the feedback current signal is higher than the first preset slope threshold, or when the slope of the frequency change of the target spectrum is higher than the second preset slope threshold, the motor 51 can be controlled to stop rotating.

[0099] It should be noted that skull drilling devices can generally be divided into skull drilling devices with mechanical unit 52 without a clutch structure and skull drilling devices with mechanical unit 52 having a clutch structure. For those without a clutch structure, the feedback current of the motor 51 of the skull drill bit 4 is different when it rotates in different bone layers, and the critical point of drilling is the boundary between different bone layers. Therefore, when the skull drill bit 4 is at the critical point, the feedback current will be different. Therefore, whether it is higher than the first preset slope threshold or the second preset slope threshold can be used as the preset current change condition for judgment.

[0100] For the skull drill device with a clutch mechanism in mechanical unit 52, in addition to the above-mentioned principle, since the motor 51 is in two states of load rotation and no-load rotation respectively when the clutch mechanism is engaged and disengaged, the feedback current is different in the two states. Therefore, when the critical point of drilling through and triggering the clutch mechanism is reached, the current will suddenly change and increase. Thus, the preset current change condition can be set to whether it is higher than the third preset slope threshold. The third preset slope threshold can be set according to the actual situation, and this embodiment does not limit it. If it is not higher than the third preset slope threshold, it means that the clutch mechanism has not been triggered to disengage at this time, and there is no need to stop, and the motor 51 can continue to rotate. If it is higher than the third preset slope threshold, it means that the clutch mechanism has been triggered to disengage at this time, and the motor 51 can be controlled to stop rotating. In this way, the existing skull drill device with mechanical clutch can be upgraded. In addition to the mechanical clutch, a current detection method is added to realize the drill-through self-stop, achieving a double insurance effect and improving the self-stop response efficiency. At the same time, it can avoid the problem of the drill bit continuing to rotate due to the motor continuing to rotate under no-load after drilling through.

[0101] Furthermore, in order to obtain the target spectrogram, continue as follows: Figure 3 As shown, in this embodiment, the skull drill device further includes: a conversion module 7;

[0102] The conversion module 7 is connected to the current acquisition module 1 and the processing module 2 respectively. The conversion module 7 is used to perform analog-to-digital conversion on the feedback current signal and transmit the converted feedback current signal to the processing module 2.

[0103] It should be noted that since the feedback current signal acquired by the current acquisition module 1 is an analog signal, the processing unit 22 can recognize digital signals. Therefore, the output terminal of the current acquisition module 1 can also be connected to the processing unit 22 through the conversion module 7. The conversion module 7 can be a module for performing analog-to-digital conversion. In this embodiment, the analog-to-digital converter can be set as the conversion module 7. That is, the feedback current signal can be converted from analog to digital by the analog-to-digital converter, and the converted feedback current signal can be transmitted to the processing unit 22 for judgment.

[0104] As another implementation method, such as Figure 4 As shown, if a differential module 6 is provided at the output of the current acquisition module 1 in this embodiment, the feedback current signal after differential amplification is an analog signal, and the processing unit 22 can identify the digital signal. Furthermore, the second end of the ninth resistor R9 and the second end of the tenth resistor R10 are also connected to the processing unit 22 through the conversion module 7. That is, the differential amplified feedback current signal can be converted from analog to digital by the analog-to-digital converter, and the converted feedback current signal is transmitted to the processing unit 22 for judgment.

[0105] Furthermore, in order to improve the signal quality of the feedback current, continue as follows Figure 3 As shown, in this embodiment, the skull drill device further includes: a filter module 8;

[0106] The filtering module 8 is connected to the conversion module 7 and the processing module 2 respectively. The filtering module 8 is used to filter the converted feedback current signal and transmit the filtered feedback current signal to the processing module 2.

[0107] Understandably, the filtering module 8 described above may include a high-pass filter and a low-pass filter. The first end of the high-pass filter can be connected to the analog-to-digital converter, the second end of the high-pass filter can be connected to the first end of the low-pass filter, and the second end of the low-pass filter can be connected to the processing unit 22. Therefore, in this embodiment, the converted feedback current signal can be subjected to high-pass filtering and low-pass filtering respectively by the high-pass filter and low-pass filter before the filtered feedback current signal is transmitted to the processing unit 22 for judgment.

[0108] It should be emphasized that the above-mentioned analog-to-digital conversion and filtering functions can also be directly implemented by the above-mentioned processing unit 22. That is, the processing unit 22 can convert the differentially amplified feedback current signal into a digital signal, determine the current value of the converted feedback current signal, and then perform high-pass filtering and low-pass filtering on the current value. Based on the filtered feedback current signal, a judgment can be made, thus eliminating the need to set up conversion module 7 and filtering module 8, saving costs.

[0109] Furthermore, in order to obtain the target spectrum, the second processing module 2 can perform a Fourier transform on the filtered feedback current signal to obtain an initial spectrum; then determine the critical frequency range, and filter the initial spectrum based on the critical frequency range to obtain the target spectrum.

[0110] It should be noted that the initial spectrum diagram mentioned above can be a graph showing the energy distribution across the entire frequency range after performing a Fourier transform on the feedback current signal. The critical frequency range mentioned above can be the frequency range among all frequencies that is related to the friction between the cutting edge of the skull drill 4 and the skull, and therefore requires special attention and can be called the critical frequency range.

[0111] In practical use, after the processing unit 22 performs a Fourier transform on the filtered feedback current signal to obtain the initial spectrum, the critical frequency range can be determined, and the spectrum in the critical frequency range can be selected from the initial spectrum as the target spectrum.

[0112] Furthermore, in order to determine a suitable critical frequency range, in this embodiment, the processing unit 22 determines the critical frequency range by the following process: the processing unit 22 obtains the current motor speed, the preset mechanical reduction ratio, and the preset number of drill bits; and determines the critical frequency based on the current motor speed, the preset mechanical reduction ratio, and the preset number of drill bits; and determines the critical frequency range based on the critical frequency.

[0113] It is understood that the current motor speed mentioned above can be the speed of motor 51 at the current moment. In this embodiment, the current motor speed can be obtained by setting a speed sensor at motor 51. Of course, it can also be obtained by other means, and this embodiment does not limit it.

[0114] The aforementioned preset mechanical reduction ratio can be the ratio between the speed of the input shaft and the speed of the output shaft in the user transmission between the motor 51 and the skull drill bit 4. Specifically, it can be... Figure 1 The ratio of the rotational speed of the input shaft to the rotational speed of the output shaft within the intermediate mechanical unit 52. In this embodiment, the reduction ratio of the above-mentioned skull drill device can be pre-stored in the above-mentioned processing unit 22 as the preset mechanical reduction ratio.

[0115] The aforementioned preset number of drill bits can be the number of drill bits 4 currently used in the skull drill device. Since different skull drill bits 4 may have different numbers of drill bits, the user can also store the corresponding preset number of drill bits in the aforementioned processing unit 22 in advance. Of course, it can also be obtained through existing tool identification methods, such as the processing unit 22 reading the number of drill bits stored in the identity chip of the currently connected skull drill bit 4, or the processing unit 22 reading the identity information of the currently connected skull drill bit 4, and then querying the number of drill bits of the corresponding model based on the identity information.

[0116] It should be understood that the critical frequency can be calculated after obtaining the current motor speed, preset mechanical reduction ratio, and preset number of drill bits. Specifically, it can be obtained through the following preset frequency calculation formula:

[0117] f = v / d * k;

[0118] Where f is the critical frequency, v is the current motor speed, d is the preset mechanical reduction ratio, and k is the preset number of drill bits.

[0119] In a specific implementation, the frequency calculated by the processing unit 22 using the above formula can be used as the critical frequency. This critical frequency can be the frequency among all frequencies that is related to the friction between the cutting edge of the skull drill 4 and the skull, and needs to be focused on. Therefore, it can be called the critical frequency. The reason for selecting this critical frequency is that the signal source used in this embodiment is a feedback current signal, whose vector value is related to the load. Its load mainly comes from the friction between the cutting edge of the skull drill 4 and the skull.

[0120] After obtaining the critical frequency, to ensure accuracy, frequencies within a certain range on both sides can be divided into the aforementioned critical frequency interval. This certain range can be a preset range; in this embodiment, ±10% is used for illustration. For example, if the calculated critical frequency is 10Hz, then the aforementioned critical frequency interval can be the range of 8Hz to 12Hz.

[0121] Furthermore, to ensure accuracy, when the processing unit 22 determines the critical frequency range based on the critical frequency, the critical frequency can be scaled; the scaled critical frequency is then windowed according to a preset range to obtain the critical frequency range.

[0122] It should be noted that the above scaling can be either shrinking or enlarging. In this embodiment, the critical frequency can be scaled down or enlarged according to a preset multiple. The preset multiple can be set according to the actual situation. In this embodiment, 1 / 4x, 1 / 2x, 2x, and 4x are used for illustration. The preset interval can be the preset range, i.e., ±10%.

[0123] In practical use, after the processing unit 22 determines the critical frequency, it can perform operations of 1 / 4, 1 / 2, 2, and 4 times. For each critical frequency after scaling, the frequency within a window of ±10% is taken, that is, the ±10% interval of the critical frequency after scaling by 1 / 4, 1 / 2, 2, and 4 times is obtained. At the same time, a corresponding second preset slope threshold can be set for each critical frequency interval. These intervals are then used as critical frequency intervals for judgment. It is determined whether the frequency change slope in each critical frequency interval is higher than the corresponding second preset slope threshold. If the frequency change slope of at least any critical frequency interval is higher than the corresponding second preset slope threshold, the rotation of motor 51 can be stopped immediately.

[0124] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A skull drill device with an automatic stop function, characterized in that, The skull drill device includes: a current acquisition module, a processing module, a motor drive module, and a motor that drives the skull drill bit. The current acquisition module is connected to both the motor and the processing module. The current acquisition module is used to acquire the current flowing through the motor to obtain a feedback current signal. The processing module is connected to the motor drive module, and the processing module is used to send a stop signal to the motor drive module when the feedback current signal reaches a preset threshold condition. The motor drive module is connected to the motor, and the motor drive module is used to receive the stop signal and control the skull drill bit to stop rotating through the motor.

2. The skull drill device as described in claim 1, characterized in that, The processing module includes: a judgment unit and a processing unit; The judgment unit is connected to the current acquisition module and the processing unit respectively. The judgment unit is used to send a drilling signal to the processing unit when the current value corresponding to the feedback current signal is higher than the preset current threshold. The processing unit is connected to the motor drive module, and the processing unit is used to receive the drilling signal and send a stop signal to the motor drive module.

3. The skull drill device as described in claim 2, characterized in that, The judgment unit includes: a comparison subunit and a switching subunit; The comparison subunit is connected to the current acquisition module and the switch subunit respectively. The comparison subunit is used to send a comparison signal to the switch subunit when the current value corresponding to the feedback current signal is higher than a preset current threshold. The switching subunit is connected to the processing unit, and the switching subunit is used to receive the comparison signal and send a drilling signal to the processing unit.

4. The skull drill device as described in claim 3, characterized in that, The comparison subunit includes: a first resistor to a third resistor and a comparator; The non-inverting input of the comparator is connected to the current acquisition module, the inverting input of the comparator is connected to the first end of the first resistor, the second end of the first resistor is connected to the second end of the second resistor and the first end of the third resistor, the first end of the second resistor is connected to the power supply, the second end of the third resistor is grounded, and the output of the comparator is connected to the switching subunit.

5. The skull drill device as described in claim 4, characterized in that, The switching subunit includes: a switching transistor, a fourth resistor, and a relay; The base of the switching transistor is connected to the output of the comparator, the emitter of the switching transistor is connected to the first end of the fourth resistor, the second end of the fourth resistor is grounded, the collector of the switching transistor is connected to the second end of the coil of the relay, the first end of the coil is connected to the power supply, the first end of the normally closed contact switch of the relay is connected to the power supply, and the second end of the normally closed contact switch is connected to the processing unit.

6. The skull drill device as described in claim 4, characterized in that, The current acquisition module includes: a current sensor; The first end of the current sensor is connected to the motor, and the second end of the current sensor is connected to the non-inverting input of the comparator.

7. The skull drill device as described in claim 1, characterized in that, The skull drill device further includes: a differential module; The differential module is connected to both the current acquisition module and the processing module. The differential module is used to differentially amplify the feedback current signal and transmit the differentially amplified feedback current signal to the processing module.

8. The skull drill device as described in claim 7, characterized in that, The differential module includes: a differential operational amplifier, a first capacitor, a second capacitor, and resistors five through ten. The current acquisition module is connected to the first end of the fifth resistor. The second end of the fifth resistor is connected to the first end of the seventh resistor and the first input end of the differential operational amplifier. The ground end of the differential operational amplifier is grounded. The second input end of the differential operational amplifier is connected to the second end of the sixth resistor and the first end of the eighth resistor. The first end of the sixth resistor is grounded. The first power supply end of the differential operational amplifier is connected to the positive power supply and the second end of the first capacitor. The first end of the first capacitor is grounded. The second power supply end of the differential operational amplifier is connected to the negative power supply and the first end of the second capacitor. The second end of the second capacitor is grounded. The first output end of the differential operational amplifier is connected to the second end of the eighth resistor and the first end of the tenth resistor. The second end of the tenth resistor is connected to the processing module. The second output end of the differential operational amplifier is connected to the second end of the seventh resistor and the first end of the ninth resistor. The second end of the ninth resistor is connected to the processing module.

9. The skull drill device as described in claim 1, characterized in that, The skull drill device further includes: a conversion module; The conversion module is connected to the current acquisition module and the processing module respectively. The conversion module is used to perform analog-to-digital conversion on the feedback current signal and transmit the converted feedback current signal to the processing module.

10. The skull drill device as described in claim 9, characterized in that, The skull drill device also includes: a filtering module; The filtering module is connected to both the conversion module and the processing module. The filtering module is used to filter the converted feedback current signal and transmit the filtered feedback current signal to the processing module.

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