Intelligent implant, system and method based on fusion detection

Abstract

The present application relates to the technical field of medical devices, in order to facilitate the detection of the fusion degree and / or temperature of the implant, an intelligent implant based on fusion degree and temperature detection is provided, comprising an implant body, at least one ultrasonic device is arranged in the implant body. The detection system comprises a signal processing terminal and an intelligent implant based on fusion degree and temperature detection. The intelligent implant fusion degree detection method judges the fusion degree of the implant according to the amplitude of the ultrasonic wave. The intelligent implant temperature detection method judges the temperature of the implant according to the propagation time of the ultrasonic wave. The above-mentioned method facilitates the detection of the fusion degree and / or temperature of the implant and has high precision.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to an intelligent implant based on fusion degree detection, a system and a method. BACKGROUND

[0002] Orthopedic implant products mainly include spine products, trauma products, artificial joint products, neurosurgery products (skull repair titanium mesh, skull bone plate), thoracic surgery products (such as sternal internal fixation implants, rib internal fixation implant products, etc.), etc. Common orthopedic implants include intervertebral fusion cages, orthopedic bone plates, orthopedic screw-rod fixation systems (such as posterior spinal pedicle screw fixation systems, anterior spinal screw-rod fixation systems, and various types), orthopedic nail-plate systems, hip joint prostheses, knee joint prostheses, artificial vertebral bodies, intramedullary nails, elbow joint prostheses, wrist joint prostheses, shoulder joint prostheses, ankle joint prostheses, screws, titanium mesh, orthopedic fixation needles, orthopedic fixation cables, orthopedic fixation rivet implants, orthopedic external fixation support implants (the nails and needles of the fixation support are implants, and the connecting rods are class 2 medical devices), orthopedic personalized custom implants, orthopedic tumor implant products, and orthopedic implant spacers. The types of orthopedic implants include but are not limited to the above-mentioned product types and categories. The higher the fusion degree of the implant after being implanted in the body indicates the better recovery of the patient. The fusion degree detection described in this patent includes bone healing, fusion, and bone integration at the orthopedic implant-bone interface. The biomechanical properties of the implant-bone interface are the determining factors for maintaining the stability of the implant. Good implant-bone interface bone integration mainly manifests as mature bone tissue closely contacting the implant interface and producing mechanical locking, and depends on the contact ratio of bone tissue and implant. The long-term stability of the prosthesis after implantation depends on the quality and quantity of the implant-bone interface bone integration. Bone integration depends on the regeneration of bone tissue at the prosthesis-bone interface. Implant-bone interface bone integration mainly involves artificial joint prostheses, oral implants, screws, pedicle screws, intervertebral fusion cages, artificial vertebral bodies, etc.

[0003] The existing technology mainly adopts surgical exploration and imaging detection (X-ray examination, CT tomography technology, nuclear magnetic resonance, etc.) for implant fusion degree detection. Due to ethical restrictions, surgical exploration is only suitable for a small number of patients undergoing revision surgery; at the same time, surgical exploration cannot observe deep structures and healing conditions due to the limitation of the field of view. Imaging detection lacks uniform quantitative standards and has poor consistency; patients need to return to the hospital for examination multiple times, which is time-consuming and costly; there is a risk of radiation; and real-time monitoring is not possible. In addition, there is another way to kill animals, take samples for Micro-CT, biomechanics, electron microscopy scanning, histological morphology, histomorphometry, bone density detection, etc., but this method is not suitable for clinical human research evaluation. SUMMARY

[0004] In order to facilitate the detection of the fusion degree of the implant, the application provides an intelligent implant, a system and a method based on fusion degree detection.

[0005] The application solves the above problems by adopting the technical scheme of:

[0006] The intelligent implant based on fusion degree and temperature detection comprises an implant body, at least one ultrasonic device is arranged in the implant body, and the ultrasonic device is used for emitting and receiving ultrasonic waves, and the emitted and received ultrasonic waves are used for fusion degree and / or temperature detection.

[0007] Further, a MEMS circuit system is further included, and the MEMS circuit system is electrically connected with the ultrasonic device.

[0008] Further, the MEMS circuit system comprises a preamplification circuit, a filter circuit, an AD conversion circuit, a control circuit, a driving circuit and a pulse excitation circuit which are electrically connected in sequence, and the preamplification circuit and the pulse excitation circuit are connected with the ultrasonic device.

[0009] Further, the pulse excitation circuit is further connected with an analog switch.

[0010] Further, an isolation circuit is arranged between the control circuit and the driving circuit.

[0011] Further, the ultrasonic devices are arranged in an array.

[0012] Further, the ultrasonic device is an ultrasonic piezoelectric sheet.

[0013] Further, the ultrasonic piezoelectric sheet is arranged in a direction towards a detection area of the implant body, and the arrangement area of the ultrasonic piezoelectric sheet is consistent with the area of the detection area of the implant body.

[0014] The detection system comprises a signal processing terminal and an intelligent implant based on fusion degree and temperature detection, and the signal processing terminal is used for performing fusion degree and / or temperature detection according to the emitted and received ultrasonic waves.

[0015] Further, the signal processing terminal performs implant fusion degree judgment according to the amplitude of the ultrasonic waves and implant temperature judgment according to the propagation time of the ultrasonic waves.

[0016] The intelligent implant fusion degree detection method is applied to a detection system and comprises the following steps.

[0017] Step 1: After the intelligent implant is implanted in the body, the signal processing terminal records the receiving signal of the ultrasonic device.

[0018] Step 2, judging the fusion degree of the implant according to the amplitude Vi of the received signal.

[0019] Further, the step 1 further comprises recording the transmitting signal of the ultrasonic device, and the step 2 specifically comprises judging the fusion degree according to the amplitude difference between the amplitude Vi of the received signal and the amplitude of the transmitting signal, and the greater the amplitude difference is, the higher the fusion degree is.

[0020] Further, the step 1 further comprises step A, recording the amplitude V0 of the ultrasonic reflection signal by the signal processing terminal before the intelligent implant is implanted in the body, and the step 2 specifically comprises judging the fusion degree according to the ratio of Vi and V0, and the smaller the ratio is, the higher the fusion degree is.

[0021] Further, an analog switch is used to select the ultrasonic piezoelectric sheet for transmitting and receiving the ultrasonic signal.

[0022] The intelligent implant temperature detection method is applied to a detection system, and the detection system comprises:

[0023] Step 1, recording the transmitting signal and the received signal of the ultrasonic device by the signal processing terminal after the intelligent implant is implanted in the body.

[0024] Step 2, judging the temperature of the implant according to the time difference between the transmitting signal and the received signal, and the greater the time difference is, the higher the temperature is.

[0025] Compared with the prior art, the present application has the beneficial effects that: since the ultrasonic wave is reflected at the heterogeneous surface, if the implant and the surrounding tissue gradually fuse, part of the ultrasonic wave can be transmitted into the surrounding tissue, and the amplitude of the reflected ultrasonic signal will be correspondingly reduced; the higher the fusion degree of the implant and the surrounding tissue is, the more obvious the transmission phenomenon of the ultrasonic wave is, and the lower the amplitude of the reflected ultrasonic signal is. Therefore, the use of ultrasonic wave to detect the fusion degree of the implant avoids the dependence on the experience of doctors, has high precision, reliable results and no radiation hazards; the intelligent implant has simple structure and is convenient to use. In addition, the transmission time of the ultrasonic wave can also be used to judge the temperature of the implant, and further judge whether the implant is infected. Through the use of the intelligent implant, the healing degree of the implant can be detected and monitored in real time, the patients with poor healing degree can be found, diagnosed and treated early, the best healing time can be avoided, and the risk of secondary surgery or delayed bone healing of the patients after the operation can be reduced. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a structural schematic view of the ultrasonic piezoelectric sheet and the implant body.

[0027] Figure 2 It is a structural schematic view of the MEMS circuit system and the ultrasonic piezoelectric sheet.

[0028] Figure 3 a graph of the amplitude of the received signal versus the fusion degree;

[0029] Figure 4 a graph of the propagation time versus the temperature;

[0030] Figure 5 a structural diagram of an ultrasonic piezoelectric sheet in an orthopedic screw;

[0031] Figure 6 a structural diagram of an ultrasonic piezoelectric sheet in a fusion cage;

[0032] Figure 7 a structural diagram of an ultrasonic piezoelectric sheet in a bone plate;

[0033] Figure 8 a structural diagram of an ultrasonic piezoelectric sheet in a hip joint prosthesis stem;

[0034] Figure 9 a structural diagram of an orthopedic screw;

[0035] Figure 10 a structural diagram of an intervertebral fusion cage when implanted in a spine;

[0036] Figure 11 a structural diagram of a bone plate;

[0037] Figure 12 a structural diagram of a hip joint prosthesis after implanted in a body;

[0038] Figure 13 a structural diagram of a shoulder joint prosthesis after implanted in a body;

[0039] Figure 14 a structural diagram of an ankle joint prosthesis after implanted in a body;

[0040] Figure 15 a structural diagram of a wrist joint prosthesis after implanted in a body;

[0041] Figure 16 a structural diagram of a knee joint prosthesis after implanted in a body;

[0042] Figure 17 a structural diagram of a titanium mesh when implanted in a spine;

[0043] Figures 18-19 a structural diagram of an intervertebral fusion cage when implanted in a spine;

[0044] Reference numerals: 1, implant body; 2, ultrasonic piezoelectric sheet; 3, screw hole. DETAILED DESCRIPTION

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0046] Example 1

[0047] like Figure 1 As shown, a smart implant based on fusion degree and temperature detection includes an implant body 1. The implant body 1 has at least one ultrasonic device inside, which is used to emit and receive ultrasonic waves for fusion degree and / or temperature detection.

[0048] Specifically, in this embodiment, the ultrasonic device uses an ultrasonic piezoelectric element 2, with several ultrasonic piezoelectric elements 2 arranged in an array. The ultrasonic wave can be emitted and received using the same ultrasonic piezoelectric element 2, or different ultrasonic piezoelectric elements 2 can be used. Applying a pulse excitation to the ultrasonic piezoelectric element 2 can generate ultrasonic waves. The reflected ultrasonic wave signal acts on the ultrasonic piezoelectric element 2, which can then generate an electrical signal.

[0049] like Figure 2 As shown, the MEMS circuit system includes a preamplifier circuit, a filter circuit, an AD conversion circuit, a control circuit, a drive circuit, and a pulse excitation circuit connected in sequence. Both the preamplifier circuit and the pulse excitation circuit are electrically connected to the ultrasonic piezoelectric element 2. To avoid interference from the pulse excitation on the received signal, an isolation circuit is also included in the circuit.

[0050] Because ultrasound has a diffusion angle, to avoid interference caused by multiple ultrasonic piezoelectric elements 2 operating simultaneously, an analog switch is used to control the ultrasonic piezoelectric elements 2, enabling them to operate in a time-sharing manner and also to detect the degree of fusion and / or temperature at different locations. In this embodiment, the analog switch sequentially activates different ultrasonic piezoelectric elements 2 according to a preset order.

[0051] Example 2

[0052] This embodiment uses an orthopedic screw as an example to illustrate the structure of the implant body 1. A schematic diagram of the orthopedic screw is shown below. Figure 9 As shown, orthopedic screws are commonly used orthopedic implants for fixation in clinical practice. Bone screws are typically used for the fixation of internal fractures or dislocations, achieving fixation by directly screwing in two different bone fragments or fixing plates. When assessing fusion, the fusion degree is primarily measured around the perimeter.

[0053] Based on Example 1, in this example, the ultrasonic piezoelectric pad array 2 is arranged circumferentially around the stud of the orthopedic screw to detect the degree of fusion around the stud. A cross-sectional view of the orthopedic screw is shown below.Figure 5 When the implant body 1 is an intramedullary nail or a dental implant, the arrangement of the array of ultrasonic piezoelectric sheets 2 can refer to the arrangement of the orthopedic screw.

[0054] Embodiment 3

[0055] This embodiment takes a square-shaped intervertebral fusion cage as an example, and a structure diagram of the intervertebral fusion cage implanted in the spine is shown in FIG. 4. The intervertebral fusion cage is one of the main components for reconstructing the stability of the spine, and the fusion degree in the six directions of up, down, left, right, front, and back needs to be detected. Figure 10

[0056] On the basis of Embodiment 1, six groups of the array of ultrasonic piezoelectric sheets 2 are arranged inside the intervertebral fusion cage, and are respectively used for emitting ultrasonic waves in different directions. A sectional view of the intervertebral fusion cage is shown in FIG. 5. Figure 6 When the implant body 1 is an artificial vertebral body or a solid titanium mesh, the arrangement of the array of ultrasonic piezoelectric sheets 2 can refer to the arrangement of the intervertebral fusion cage. A structure diagram of the titanium mesh implanted in the spine is shown in FIG. 6. Figure 17

[0057] Embodiment 4

[0058] This embodiment takes a bone plate as an example, and a structure diagram of the bone plate is shown in FIG. 7. The bone plate is a plate-shaped bone fracture internal fixation device with screw holes 3, and is often used in cooperation with bone screws or bone wires in clinical practice. When the fusion degree is detected, the fusion degree between the bottom surface of the bone plate and the bone is mainly detected. Figure 11

[0059] On the basis of Embodiment 1, one layer of the array of ultrasonic piezoelectric sheets 2 is arranged on the bone plate, and is used for emitting ultrasonic waves downward. A sectional view of the bone plate is shown in FIG. 8. Figure 7

[0060] Embodiment 5

[0061] This embodiment takes a hip joint prosthesis as an example, and a structure diagram of the hip joint prosthesis implanted in the body is shown in FIG. 9. This embodiment is mainly used for detecting the fusion degree at the bone stem, and therefore the array of ultrasonic piezoelectric sheets 2 for detecting in all directions and the array of ultrasonic piezoelectric sheets for detecting the tail end of the bone stem are arranged on the bone stem of the hip joint prosthesis. A sectional view of the vertical part of the bone stem is shown in FIG. 10. Figure 12 Figure 8

[0062] ​​​​​​Other artificial joint prostheses such as elbow joint prostheses, wrist joint prostheses, artificial intervertebral disc prostheses, shoulder joint prostheses, ankle joint prostheses and knee joint prostheses can also be provided with ultrasonic devices at corresponding positions to achieve fusion degree detection. For example, a shoulder joint prosthesis can detect the fusion degree between the ball head and the humeral stem and the surrounding tissue, an ankle joint prosthesis can detect the fusion degree between the prosthesis and the tibia, a wrist joint prosthesis can detect the fusion degree between the prosthesis and the carpal bone and the radius, and a knee joint prosthesis can detect the fusion degree between the prosthesis and the femur and the tibia. The specific arrangement of the ultrasonic device is determined by the area to be detected, and will not be described here. Figures 13-16 The structure of the shoulder joint prosthesis, the ankle joint prosthesis, the wrist joint prosthesis and the knee joint prosthesis after being implanted in the body is shown respectively.

[0063] In any one of embodiments 2 to 5, in order to ensure the transmission distance of the ultrasonic waves, the ultrasonic piezoelectric sheet array is arranged at a position close to the center line of the implant body, such as the transverse center line or the vertical center line.

[0064] Embodiment 6

[0065] The embodiment provides a detection system, which comprises a signal processing terminal and the intelligent implant based on fusion degree and temperature detection according to any one of the above embodiments, and the signal processing terminal is used for fusion degree and / or temperature detection according to the transmitted and received ultrasonic waves.

[0066] Specifically, the signal processing terminal judges the fusion degree of the implant according to the amplitude of the ultrasonic wave, and judges the temperature of the implant according to the propagation time of the ultrasonic wave.

[0067] The intelligent implant fusion degree detection method is applied to the detection system, and comprises the following steps:

[0068] Step 1: After the intelligent implant is implanted in the body, the signal processing terminal records the received signal of the ultrasonic device in real time;

[0069] Step 2: The fusion degree of the implant is judged according to the amplitude Vi of the received signal.

[0070] The embodiment provides two methods for judging the fusion degree of the implant according to the amplitude Vi of the received signal:

[0071] Method 1: the step 1 further comprises recording the transmitted signal of the ultrasonic device; and the step 2 specifically judges the fusion degree according to the amplitude of the received signal Vi and the amplitude of the transmitted signal. The greater the difference between the amplitudes, the higher the fusion degree of the implant. The greater the difference between the amplitude of the received signal and the amplitude of the transmitted signal, the fewer the reflected ultrasonic waves, so the smaller the amplitude of the received signal, and the higher the fusion degree of the prosthesis. The relationship between the amplitude of the received signal and the fusion degree is as shown in the following table: Figure 3The way is suitable for the case that the outer wall of the implant body is parallel to the ultrasonic piezoelectric sheet.

[0072] When the outer wall of the implant body is not parallel to the ultrasonic piezoelectric sheet, method 2 is adopted: before the step 1, a step A is further included, that is, recording the amplitude V0 of the ultrasonic reflection signal before the intelligent implant is implanted in the body; and the step 2 is specifically that the fusion degree is judged according to the ratio of Vi and V0, and the smaller the ratio is, the higher the fusion degree is.

[0073] The relationship between the amplitude of the reflection signal and the fusion degree can be expressed as: ; f is a fusion degree judgment function of different implants, and the function formula can be obtained through finite element simulation or experiment.

[0074] Further, an analog switch can be used to select the ultrasonic piezoelectric sheet for transmitting and receiving ultrasonic signals, so as to realize the fusion degree detection of different positions of the intelligent implant.

[0075] The intelligent implant temperature detection method is applied to the detection system and includes the following steps:

[0076] Step 1: After the intelligent implant is implanted in the body, the signal processing terminal records the transmission signal and the receiving signal of the ultrasonic transceiver in real time.

[0077] Step 2: The time difference between the transmission signal and the receiving signal is used to judge the temperature of the implant: the larger the time difference between the transmission signal and the receiving signal is, the higher the temperature of the implant is. The higher the temperature is, the longer the propagation time of the ultrasonic wave is, and the relationship between the transmission time and the temperature is as shown in Figure 4 .

[0078] The fusion degree described in the present application includes bone healing, fusion and bone integration of the implant-bone interface. Taking the bone integration of the implant-bone interface as an example, there are mainly three processes in the process of the bone integration of the implant-bone interface: the interface gap, the fibrous soft tissue or the bone between the implant and the bone interface, and the fusion diagram of the intervertebral fusion cage and the spine is as shown in Figures 18-19 , the larger the area of the shadow part is, the higher the fusion degree is. The principle of using the ultrasonic wave for detection in the present application is: , ; in the formula, r is the sound pressure reflectivity, t is the sound pressure transmissivity, Z is the acoustic impedance and Z = ρC (ρ is the density of the medium, and C is the ultrasonic speed), P r is the reflected wave sound pressure, P0 is the incident wave sound pressure, P t is the transmitted wave sound pressure, Z1 and Z2 are the acoustic impedances of the two media respectively.

[0079] Assume that Z2 is the acoustic impedance of the implant body, and Z1 is the acoustic impedance of some material in contact with the surface of the implant body (the acoustic impedance of solid > the acoustic impedance of muscle tissue > the acoustic impedance of liquid > the acoustic impedance of air). When the implant body is not implanted in the body, the material in contact with the surface of the implant body is air, and the acoustic impedance of air is assumed to be 1. The acoustic impedance of the implant body material is generally thousands of times that of air, so r≈1 and t≈0, i.e., the ultrasound wave is almost totally reflected. After the implant body is implanted in the body, if the implant body does not contact the bone, the non-contacting area will be filled with blood and other soft tissue. At this time, the reflectivity of the ultrasound wave is reduced relative to that before implantation, but is still very large, i.e., the transmissivity of the ultrasound wave is relatively small. When the implant body is in good contact with the bone and gradually fuses, as the cartilage hardens, Z1 increases, and the reflectivity r of the ultrasound wave decreases, and the transmissivity t of the ultrasound wave increases. Therefore, the fusion of the implant body can be determined by the amplitude of the ultrasound echo signal.

Claims

1. A smart implant based on fusion degree detection, comprising an implant body, characterized in that, At least one ultrasonic device is disposed inside the implant body. The ultrasonic device is used to emit and receive ultrasonic waves. The emitted and received ultrasonic waves are used for fusion degree detection. The ultrasonic device is an ultrasonic piezoelectric pad. The specific detection method is as follows: when the outer wall of the implant body is parallel to the ultrasonic piezoelectric pad, the fusion degree is judged based on the amplitude Vi of the received signal and the amplitude of the emitted signal. The greater the amplitude difference, the higher the fusion degree. When the outer wall of the implant body is not parallel to the ultrasonic piezoelectric pad, the fusion degree is judged based on the ratio of the amplitude Vi of the received signal to V0. The smaller the ratio, the higher the fusion degree. V0 is the amplitude of the ultrasonic wave reflected signal before the smart implant is implanted into the body.

2. The smart implant based on fusion degree detection according to claim 1, characterized in that, It also includes a MEMS circuit system, which is electrically connected to the ultrasonic device.

3. The smart implant based on fusion degree detection according to claim 2, characterized in that, The MEMS circuit system includes a preamplifier circuit, a filter circuit, an AD conversion circuit, a control circuit, a drive circuit, and a pulse excitation circuit that are connected in sequence. The preamplifier circuit and the pulse excitation circuit are both connected to the ultrasonic device.

4. The smart implant based on fusion degree detection according to claim 3, characterized in that, The pulse excitation circuit is also connected to an analog switch.

5. The smart implant based on fusion degree detection according to claim 3, characterized in that, An isolation circuit is provided between the control circuit and the drive circuit.

6. The smart implant based on fusion degree detection according to any one of claims 1 to 5, characterized in that, The ultrasonic devices are arranged in an array.

7. The smart implant based on fusion degree detection according to claim 1, characterized in that, The ultrasonic piezoelectric patch is positioned towards the area to be tested on the implant body, and the area of ​​the ultrasonic piezoelectric patch is the same as the area of ​​the area to be tested on the implant body.

8. A detection system, characterized in that, The invention includes a signal processing terminal and a smart implant based on fusion degree detection as described in any one of claims 1 to 7. The signal processing terminal is used to perform fusion degree detection based on the transmitted and received ultrasonic waves. Specifically, the detection method is as follows: when the outer wall of the implant body is parallel to the ultrasonic piezoelectric pad, the fusion degree is judged based on the amplitude Vi of the received signal and the amplitude of the transmitted signal. The greater the amplitude difference, the higher the fusion degree. When the outer wall of the implant body is not parallel to the ultrasonic piezoelectric pad, the fusion degree is judged based on the ratio of the amplitude Vi of the received signal to V0. The smaller the ratio, the higher the fusion degree. V0 is the amplitude of the ultrasonic wave reflected signal before the smart implant is implanted into the body.

9. A method for detecting the integration degree of intelligent implants, applied to the detection system as described in claim 8, characterized in that, include: Step 1: After the smart implant is implanted in the body, the signal processing terminal records the signal received by the ultrasound device. Step 2: When the outer wall of the implant body is parallel to the ultrasonic piezoelectric patch, the degree of fusion is judged based on the amplitude Vi of the received signal and the amplitude of the transmitted signal. The greater the difference in amplitude, the higher the degree of fusion. When the outer wall of the implant body is not parallel to the ultrasonic piezoelectric patch, the degree of fusion is judged based on the ratio of the amplitude Vi of the received signal to V0. The smaller the ratio, the higher the degree of fusion. V0 is the amplitude of the ultrasonic reflected signal before the smart implant is implanted into the body.

10. The method for detecting the integration degree of intelligent implants according to claim 9, characterized in that, An analog switch is used to select the ultrasonic piezoelectric element that transmits and receives ultrasonic signals.

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