A collision detection device, implantation system and method for steel plate implantation process

Abstract

This invention relates to a collision detection device, implantation system, and method for plate implantation, comprising a piezoelectric vibrator, a signal generating device, and an accelerometer. The piezoelectric vibrator is mounted on a plate clamp connected to the end of a robotic arm and is connected to the signal generating device, which drives the piezoelectric vibrator to vibrate. The accelerometer is fixed to Kirschner wires at the proximal and distal ends of the fracture bone and is connected to a control terminal. The piezoelectric vibrator applies vibration to the plate during implantation to transmit the vibration to the accelerometer. The change in the vibration signal output by the accelerometer determines whether a collision has occurred between the plate and the fracture bone. The collision detection device of this invention enables collision detection during plate implantation, reducing the probability of medical accidents.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a collision detection device, implantation system, and method for steel plate implantation. Background Technology

[0002] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art.

[0003] In current fracture surgery, robotic arms can accurately implant plates into the target location even without a visual field. Using robotic arms for plate placement can improve the accuracy of plate placement, reduce the occurrence of various accidents caused by large plate placement deviations, reduce the number of fluoroscopy sessions and the degree of doctor's involvement in the operation, reduce the impact of radiation on doctors and patients, and reduce the difficulty of the operation. However, there is a risk of collision between the plate and the fracture bone during the implantation process using robotic arms. Because the soft tissue along the implantation path needs to be torn during the plate implantation process, the plate is always under great force during the implantation process. Therefore, it is impossible to accurately judge the collision situation by the force on the end of the robotic arm, and collision detection cannot be solved by visual methods during plate implantation surgery. Therefore, collision detection during the implantation of plates with robotic arms is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a collision detection device, implantation system, and method for steel plate implantation, which solves the problem that current robotic arms cannot perform collision detection when implanting steel plates.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0006] In a first aspect, embodiments of the present invention provide a collision detection device for steel plate implantation process, including a piezoelectric vibrator, a signal generating device, and an acceleration sensor;

[0007] The piezoelectric vibrator is used to be installed on the steel plate clamp connected to the end of the robotic arm. The piezoelectric vibrator is connected to a signal generating device, which can drive the piezoelectric vibrator to vibrate.

[0008] Accelerometers are used to fix Kirschner wires at the proximal and distal ends of the fractured bone, and the accelerometers are connected to the control terminal.

[0009] The piezoelectric vibrator can apply vibration to the steel plate during the implantation process to transmit the vibration to the accelerometer. The change in the output signal of the accelerometer can be used to determine whether the steel plate has collided with the broken bone.

[0010] Optionally, the signal generating device includes a signal generator connected to a power amplifier, and the power amplifier connected to a piezoelectric vibrator.

[0011] Optionally, the accelerometer is bonded and fixed to the Kirschner wire;

[0012] or,

[0013] The accelerometer is detachably mounted on a sensor bracket, which is used for welding and fixing with Kirschner wires.

[0014] Secondly, embodiments of the present invention provide a plate implantation system, including the collision detection device for the plate implantation process described in the first aspect, and further including a robotic arm, a plate clamp, and Kirschner wires. The robotic arm is connected to a control terminal, and a plate clamp is provided at the end of the robotic arm for fixing the plate. The piezoelectric vibrator is fixed on the plate clamp, and the Kirschner wires are used to insert into the proximal and distal ends of the fracture bone. Among the plurality of Kirschner wires used to cooperate with the proximal end of the fracture bone, at least one Kirschner wire is fixed with an acceleration sensor, and among the plurality of Kirschner wires used to cooperate with the distal end of the fracture bone, at least one Kirschner wire is fixed with an acceleration sensor.

[0015] Optionally, a force sensor is provided between the end effector of the robotic arm and the steel plate clamp.

[0016] Optionally, the steel plate clamp adopts an L-shaped structure, including a first clamp part and a second clamp part that are perpendicular to each other. The first clamp part is connected to the end of the robotic arm, and the second clamp part is provided with a positioning protrusion that can be embedded in the positioning recess of the steel plate clamp. The second clamp part can be detachably and fixedly connected to the steel plate by threaded fasteners.

[0017] Thirdly, embodiments of the present invention provide a collision detection method for the steel plate implantation system described in the second aspect:

[0018] The signal generating device drives the piezoelectric vibrator to vibrate at a set excitation frequency;

[0019] During the implantation of the steel plate by the robotic arm, the piezoelectric array transmits vibrations through the steel plate to the accelerometer.

[0020] When the control terminal receives a vibration signal change value from the accelerometer that is greater than the set threshold, it determines that the steel plate has collided with the broken bone; otherwise, it determines that the steel plate has not collided with the broken bone.

[0021] Optionally, the output vibration signal of the accelerometer is subjected to Fourier transform to obtain the main frequency and amplitude of the fracture vibration signal, and the obtained main frequency and amplitude are used to determine whether the steel plate has collided with the fracture.

[0022] Optionally, the excitation frequency can be obtained as follows:

[0023] The robotic arm moves the steel plate, causing the end of the steel plate to make contact with the broken bone through the cut with a set contact force;

[0024] The signal generating device sweeps the frequency within a set frequency range to drive the piezoelectric array to vibrate.

[0025] The control terminal collects the vibration signal output by the accelerometer during the frequency sweep process;

[0026] The excitation frequency is determined by the vibration frequency output by the signal generator that maximizes the vibration acceleration of the fracture bone during the frequency sweep process, based on the vibration signal output by the accelerometer.

[0027] Optionally, the contact force is set to 0.8N-1.2N, preferably 1N.

[0028] The beneficial effects of this invention are as follows:

[0029] 1. The collision detection device, implantation system, and method for steel plate implantation of the present invention can transmit vibration to the steel plate through a piezoelectric array. During the implantation process, the steel plate transmits the vibration to an accelerometer. When the steel plate does not collide with the fractured bone during implantation, the vibration of the steel plate is transmitted to the accelerometer through the soft tissue. When the steel plate collides with the fractured bone, the vibration of the steel plate is transmitted to the accelerometer through the soft tissue and bone, causing the output vibration signal of the accelerometer to change. This realizes collision detection during the steel plate implantation process, fills the technical gap in this area, solves the problem of collision detection during steel plate implantation, and reduces the probability of medical accidents while giving full play to the advantages of robotic arm-assisted steel plate implantation.

[0030] 2. The collision detection device, implantation system and method for steel plate implantation of the present invention uses a set excitation frequency to drive the piezoelectric array to vibrate. The excitation frequency is the frequency corresponding to the maximum vibration acceleration output by the accelerometer when the steel plate comes into contact with the broken bone. This makes the change in the output signal of the accelerometer more obvious when the steel plate collides with the broken bone, and makes it easier for medical staff to identify the collision between the steel plate and the broken bone.

[0031] 3. The collision detection device, implantation system and method for steel plate implantation of the present invention performs Fourier transform on the vibration signal output by the acceleration sensor, and determines whether the steel plate collides with the fractured bone by the main frequency and amplitude, thereby avoiding the influence of environmental noise and random vibration in the operating room and ensuring the accuracy of the collision detection results. Attached Figure Description

[0032] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0033] Figure 1 This is a schematic diagram of the usage state of Embodiment 1 of the present invention;

[0034] Among them, 1. Signal generator, 2. Power amplifier, 3. Mechanical sensor, 4. Piezoelectric vibrator, 5. Accelerometer, 6. Kirschner wire, 7. Steel plate clamp, 8. Steel plate, 9. Control terminal, 10. Robotic arm. Detailed Implementation

[0035] In this embodiment, the proximal end of the fracture refers to the part of the bone that is fixed to the operating table using Kirschner wires, while the distal end of the fracture refers to the part that is connected to the repositioning device via Kirschner wires.

[0036] The vibration signal output by the accelerometer is an acceleration signal, which is a type of vibration signal. Vibration signals include acceleration signals, velocity signals, and displacement signals.

[0037] Example 1

[0038] This embodiment provides a collision detection device for steel plate implantation process, including a piezoelectric vibrator 4, a signal generating device and multiple acceleration sensors 5.

[0039] The piezoelectric vibrator 4 is connected to a signal generating device, which can drive the piezoelectric vibrator 4 to vibrate. The piezoelectric vibrator 4 is used to be installed on the steel plate clamp 7 at the end of the robotic arm 10. The steel plate clamp 7 is used to fix the steel plate 8 to be implanted. The piezoelectric vibrator 4 can transmit the vibration to the steel plate 8 through the steel plate clamp 7.

[0040] In this embodiment, the signal generating device includes a signal generator 1, which is connected to a power amplifier 2. The power amplifier 2 is connected to a piezoelectric vibrator 4. The signal generator 1 is used to emit an initial drive signal for the piezoelectric vibrator 4, and the power amplifier 2 is used to amplify the initial drive signal emitted by the signal generator 1 to drive the piezoelectric vibrator 4 to vibrate.

[0041] The signal generator 1, power amplifier 2, and piezoelectric vibrator 4 can be achieved using existing instruments and equipment; their specific structures will not be described in detail here.

[0042] The accelerometer 5 is fixed to the Kirschner wire 6, which is inserted into the fractured bone to temporarily fix it.

[0043] The accelerometer 5 is connected to the control terminal 9 and can send vibration signals to the control terminal 9. The control terminal 9 can receive the vibration signals sent by the accelerometer 5 and process the vibration signals to determine whether the steel plate collides with the broken bone.

[0044] In this embodiment, the piezoelectric vibrator 4 is fixed on the steel plate clamp 7. During the implantation of the steel plate 8, the piezoelectric vibrator 4 transmits vibration to the steel plate 8 through the steel plate clamp 7. During the implantation of the steel plate 8, the vibration of the steel plate 8 can be transmitted to the acceleration sensor 5. After receiving the vibration, the acceleration sensor 5 transmits the vibration signal to the control terminal 9. When the vibration signal output by the acceleration sensor 5 changes to exceed the set threshold, it is determined that the steel plate has collided with the broken bone; otherwise, it is determined that the steel plate has not collided with the broken bone.

[0045] Example 2

[0046] This embodiment provides a steel plate implantation system, including the collision detection device for the steel plate implantation process described in Embodiment 1.

[0047] It also includes a robotic arm 10 and a steel plate clamp 7.

[0048] The robotic arm 10 can be any existing robotic arm, and its specific structure will not be described in detail here.

[0049] The end of the robotic arm 10 is connected to a steel plate clamp 7 via a mechanical sensor 3. The steel plate clamp 7 can be detachably and fixedly connected to the steel plate 8 to be implanted. The mechanical sensor 3 can be an existing sensor, such as a pressure sensor. The mechanical sensor 3 is used to detect the pressure, torque and other mechanical information of the end of the robotic arm during the steel plate implantation process.

[0050] The mechanical sensor 3 is connected to the control terminal 9 and can transmit the detected mechanical information to the control terminal 9.

[0051] The steel plate clamp 7 adopts an L-shaped structure, including a first clamp part and a second clamp part that are perpendicular to each other. One end of the first clamp part is fixedly connected to the force sensor 3, and the other end is fixedly connected to one end of the second clamp part. The end of the second clamp part is provided with multiple positioning protrusions. In this embodiment, three positioning protrusions are provided that match the positioning recesses at the end of the steel plate. The second clamp part is provided with a connecting hole that matches the fixing hole at the end of the steel plate 8. The second clamp part can be detachably and fixedly connected to one end of the steel plate 8 through the connecting hole and the threaded connector.

[0052] Threaded fasteners can be bolts or screws, and those skilled in the art can set them according to actual needs.

[0053] The piezoelectric vibrator 4 is fixed on the steel plate clamp 7. In this embodiment, the piezoelectric vibrator 4 is fixed on the first clamp part.

[0054] The Kirschner wires 6 are multiple in number and are used to be inserted into the fractured bone for temporary fixation.

[0055] The fractured bone includes a proximal end and a distal end. Some Kirschner wires 6 are used to insert into the proximal end of the fractured bone. The Kirschner wires 6 inserted into the proximal end of the fractured bone are used to connect to a fixation frame via a clamp. The fixation frame is used to fix the fractured bone on the operating table, thus achieving temporary fixation of the proximal end of the fractured bone. The clamp and fixation frame can be made using existing technology, and will not be described in detail here.

[0056] Another part of the Kirschner wires 6 are used to insert into the distal end of the fracture. The Kirschner wires 6 inserted into the distal end of the fracture can be connected to the repositioning device through a clamp. The repositioning device is used to drive the distal end of the fracture to move through the Kirschner wires, so that the distal end of the fracture moves to a set position to achieve the combination of the proximal end and the distal end of the fracture.

[0057] In this embodiment, the repositioning device can be a robotic arm. The end of the robotic arm is connected to the Kirschner wire 6 through a clamp. The clamp can be made using existing technology and will not be described in detail here. Therefore, the entire operation requires two robotic arms to work together, one for the implantation of the steel plate and the other for the repositioning of the distal end of the broken bone.

[0058] Among the multiple Kirschner wires 6 used for insertion into the proximal end of the fracture bone, at least one Kirschner wire 6 is fixed with an acceleration sensor. In this embodiment, one Kirschner wire 6 is fixed with an acceleration sensor 5. Among the multiple Kirschner wires 6 used for insertion into the distal end of the fracture bone, at least one Kirschner wire 6 is fixed with an acceleration sensor. In this embodiment, one Kirschner wire 6 is fixed with an acceleration sensor 5.

[0059] In one embodiment, the accelerometer 5 is directly bonded to the Kirschner wire 6.

[0060] In another embodiment, the accelerometer 5 is fixed to a metal sensor bracket by screws or bolts, and the sensor bracket is welded to the Kirschner wire 6.

[0061] Those skilled in the art can choose the fixing method of the accelerometer 5 and the Kirschner wire 6 according to actual needs, which will not be described in detail here.

[0062] The robotic arm 10, the force sensor 3, and the acceleration sensor 5 are all connected to the control terminal. The force sensor 3 can send force signals to the control terminal 9, and the acceleration sensor 5 can send vibration signals to the control terminal 9. The control terminal 9 can control the robotic arm 10 to work, so that the robotic arm 10 implants the steel plate 8 according to the set trajectory.

[0063] Example 3

[0064] This embodiment provides a collision detection method for the steel plate implantation system described in Embodiment 2, using a femoral shaft fracture as an example:

[0065] The robotic arm 10 moves the steel plate 8 to the starting point of the steel plate 8 implantation via the steel plate clamp 7. The signal generator 1 drives the piezoelectric vibrator 4 to vibrate at the set excitation frequency via the power amplifier 2. The piezoelectric vibrator 4 drives the steel plate 8 to vibrate at the set excitation frequency via the steel plate clamp 7.

[0066] The control terminal 9 controls the robotic arm 10 to move the steel plate 8 along a pre-set path for implantation. In this embodiment, a small incision is made in the condyle and the steel plate is implanted along the femur. Compared to open reduction and fixation with a steel plate, this implantation method causes less damage to soft tissue, thus protecting the blood supply to the fracture area and facilitating bone recovery. During the implantation process, the piezoelectric vibrator 4 transmits vibrations through the steel plate 8 to the accelerometer 5. The accelerometer 5 transmits vibration signals to the control terminal 9 in real time. In this embodiment, the vibration signal is an acceleration signal.

[0067] When the control terminal 9 receives a vibration signal change value from the acceleration sensor 5 that is greater than the set threshold, it determines that the steel plate 8 has collided with the broken bone; otherwise, it determines that the steel plate 8 has not collided with the broken bone.

[0068] In this embodiment, when the steel plate 8 does not collide with the fractured bone, the vibration of the steel plate 8 is transmitted to the accelerometer 5 through the soft tissue; when the steel plate 8 collides with the fractured bone, the vibration of the steel plate is transmitted to the accelerometer 5 through both the soft tissue and the bone. Since the vibration transmission capacity of the bone is much greater than that of the soft tissue, the vibration signal received by the accelerometer 5 will increase significantly before and after the steel plate 8 collides with the fractured bone. Therefore, the change in the vibration signal output by the accelerometer can be used to determine whether the steel plate 8 has collided with the fractured bone.

[0069] To avoid the influence of environmental noise or random vibration in the operating room, the control terminal 9 performs Fourier transform on the vibration signal transmitted by the accelerometer 5 to obtain the main frequency and amplitude of the fracture vibration signal. The main frequency and amplitude are used as dual detection standards to determine whether the steel plate 8 has collided with the fracture, thus ensuring the accuracy of the judgment result.

[0070] When the main frequency change value of the fracture vibration signal transmitted by the accelerometer 5 exceeds the set main frequency change threshold and the amplitude change value exceeds the set amplitude change threshold, that is, when the main frequency of the fracture vibration signal changes to within the range of excitation frequency ±a and the amplitude changes to greater than b, it is determined that the steel plate 8 has collided with the fracture bone. Here, a is 2Hz-5Hz and b is 2.5 times to 5 times the gravitational acceleration. In this embodiment, the values ​​of a and b are determined by the equipment accuracy and the mechanical properties of the affected limb, which will not be described in detail here.

[0071] In this embodiment, when a surgical instrument (such as a scalpel, orthopedic drill, instrument tray, etc.) accidentally falls onto the surgical platform or the Kirschner wire 6 used to fix the fractured bone, it will cause a drastic change in the signal of the accelerometer 5. Theoretically, when a specific surgical instrument falls to a specific position at a specific angle, there is a possibility that the dominant frequency of the vibration signal output by the accelerometer 5 is equal to the excitation frequency ± a, and the amplitude is greater than b, thus causing a false detection. However, since the connection between the bone, soft tissue, Kirschner wire, accelerometer, Kirschner wire fixation device, and tabletop introduces a large number of nonlinear properties into the entire vibration system, the vibration curve caused by the falling surgical instrument will not be a constant frequency sine curve without stable excitation. Based on this characteristic, the criterion for judging whether the plate 8 collides with the fractured bone is modified to determine a collision when the dominant frequency is equal to the excitation frequency ± a and the amplitude is greater than b after two consecutive detections, which can further reduce the probability of false detection. Although this will have some impact on the sensitivity of the collision detection method, since the detection frequency of the accelerometer is 25kHz and the implantation speed during the plate implantation process is relatively slow, its impact is very limited. Therefore, for experimental environments where there is a risk of accidental drops, the above testing standards are recommended to reduce the probability of false detections.

[0072] In this embodiment, the method for obtaining the excitation frequency includes the following steps:

[0073] Step 1: Make an incision at the femoral condyle.

[0074] Step 2: The control terminal 9 controls the movement of the end of the robotic arm 10 so that the end of the steel plate 8 contacts the femoral condyle through the incision. The contact force is 0.8N-1.2N, preferably 1N. The contact force is controlled by the reading of the force sensor.

[0075] Step 3: The signal transmitter 1 sweeps the frequency within the set frequency range. The signal is amplified by the power amplifier 2 and then drives the piezoelectric vibrator 4 to vibrate.

[0076] Step 4: The control terminal 9's data acquisition card collects the vibration signal output by the proximal accelerometer 5 of the fractured bone during the frequency sweep process. The control terminal 9 reads the vibration signal collected by the data acquisition card and determines the frequency output by the signal generator 1 that maximizes the vibration acceleration of the proximal fractured bone during the frequency sweep process as the excitation frequency. In this embodiment, the excitation frequency is 500Hz-1000Hz, determined by the mechanical properties of the affected limb. For the same affected limb, the mechanical properties of the proximal and distal ends of the fractured bone are similar; therefore, the excitation frequency obtained through the proximal fractured bone is used as the excitation frequency for the entire implantation process.

[0077] In this embodiment, the excitation frequency is the frequency corresponding to the maximum vibration acceleration output by the accelerometer when the steel plate 8 comes into contact with the fracture bone. This makes the change in the output signal of the accelerometer 5 more obvious when the steel plate collides with the fracture bone, making it easier for medical staff to identify the collision between the steel plate and the fracture bone.

[0078] The collision detection device, implantation system and method of this embodiment realize collision detection during the steel plate implantation process, fill the technical gap in this area, solve the problem of collision detection during steel plate implantation, and reduce the probability of medical accidents while giving full play to the advantages of robotic arm-assisted steel plate implantation.

[0079] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A collision detection device for steel plate implantation process, characterized in that, This includes piezoelectric vibrators, signal generating devices, and accelerometers; The piezoelectric vibrator is used to be installed on the steel plate clamp connected to the end of the robotic arm. The piezoelectric vibrator is connected to a signal generating device, which can drive the piezoelectric vibrator to vibrate. Accelerometers are used to fix Kirschner wires at the proximal and distal ends of the fractured bone, and the accelerometers are connected to the control terminal. Piezoelectric vibrators can apply vibration to the steel plate during the implantation process to transmit the vibration to an accelerometer. The change in the vibration signal output by the accelerometer can be used to determine whether the steel plate has collided with the broken bone.

2. The collision detection device for steel plate implantation process as described in claim 1, characterized in that, The signal generating device includes a signal generator, which is connected to a power amplifier, and the power amplifier is connected to a piezoelectric vibrator.

3. The collision detection device for steel plate implantation process as described in claim 1, characterized in that, The accelerometer sensor is bonded and fixed to the Kirschner wire; or, The accelerometer is detachably mounted on a sensor bracket, which is used for welding and fixing with Kirschner wires.

4. A steel plate implantation system, characterized in that, The device includes a collision detection device for plate implantation as described in any one of claims 1-3, and further includes a robotic arm, a plate clamp, and Kirschner wires. The robotic arm is connected to a control terminal, and the end of the robotic arm is provided with a plate clamp for fixing the plate. The piezoelectric vibrator is fixed on the plate clamp. The Kirschner wires are used to insert into the proximal and distal ends of the fracture bone. Among the plurality of Kirschner wires used to cooperate with the proximal end of the fracture bone, at least one Kirschner wire is fixed with an acceleration sensor. Among the plurality of Kirschner wires used to cooperate with the distal end of the fracture bone, at least one Kirschner wire is fixed with an acceleration sensor.

5. A steel plate implantation system as described in claim 4, characterized in that, A mechanical sensor is installed between the end of the robotic arm and the steel plate clamp.

6. A steel plate implantation system as described in claim 4, characterized in that, The steel plate clamp adopts an L-shaped structure, including a first clamp part and a second clamp part that are perpendicular to each other. The first clamp part is connected to the end of the robotic arm, and the second clamp part is provided with a positioning protrusion that can be embedded in the positioning recess of the steel plate clamp. The second clamp part can be detachably and fixedly connected to the steel plate by threaded fasteners.

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