CN115486873A - Intelligent implant, system and method based on fusion degree and temperature detection - Google Patents

Abstract

The invention relates to the technical field of medical devices. In order to facilitate the detection of implant fusion degree and/or temperature, an intelligent implant based on fusion degree and temperature detection is provided, including an implant body. At least one ultrasonic device is arranged inside the body. Detection system, including signal processing terminals and intelligent implants based on fusion and temperature detection. The intelligent implant fusion degree detection method judges the implant fusion degree according to the amplitude of the ultrasonic wave. The intelligent implant temperature detection method judges the implant temperature according to the propagation time of the ultrasonic wave. Adopting the above method facilitates detection of implant fusion degree and/or temperature with high precision.

Description

Intelligent implant, system and method based on fusion degree and temperature detection

technical field

The invention relates to the technical field of medical devices, in particular to an intelligent implant, system and method based on fusion degree and temperature detection.

Background technique

Orthopedic implant products mainly include spine products, trauma products, artificial joint products, neurosurgery products (titanium mesh for skull repair, skull plate), orthopedic products for thoracic surgery (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, etc.), orthopedic screw-plate System, hip prosthesis, knee prosthesis, artificial vertebral body, intramedullary nail, elbow prosthesis, wrist prosthesis, shoulder prosthesis, ankle prosthesis, screws, titanium mesh, orthopedic fixation pins, orthopedics Fixation cables, orthopedic fixed riveting implants, orthopedic external fixation implants (nails and needles for fixing brackets are implants, and connecting rods are Class 2 medical devices), orthopedic personalized implants, orthopedic tumors Implant products, orthopedic implant spacers, etc., orthopedic implant types include but are not limited to the above product types and categories. When the implant is in the body, the more it fuses with the surrounding tissue, the better the patient is recovering. The degree of fusion described in this patent includes bone healing, fusion, and osseointegration of the orthopedic implant-bone interface. The biomechanical properties of the implant-bone interface are determinants of implant stability. Good implant-bone interface osseointegration is mainly characterized by close contact between mature bone tissue and implant interface and mechanical locking, which depends on the contact ratio between bone tissue and implant. Long-term stability after implantation depends on the quality and quantity of osseointegration at the implant-bone interface. Osseointegration depends on regeneration of bone tissue at the prosthesis-bone interface. The osseointegration of the implant-bone interface mainly involves artificial joint prosthesis, dental implants, screws, pedicle screws, intervertebral cages, artificial vertebral bodies, etc.

In the prior art, surgical exploration and imaging detection (X-ray examination, CT tomographic scanning technology, nuclear magnetic resonance, etc.) are mainly used in the detection of implant fusion. Due to ethical limitations, surgical exploration is only suitable for a very small number of patients undergoing revision surgery. At the same time, surgical exploration cannot observe deep structures and healing conditions due to the limited field of view. There is no unified quantitative standard for imaging detection, and the consistency is poor; patients need to go back to the hospital for examination many times, which is time and economical; there are radiation hazards; and real-time monitoring is not possible. In addition, there is another way to kill animals and take specimens for Micro-CT, biomechanics, electron microscope scanning, histomorphology, histomorphometry, bone density and other tests, but this method is not suitable for clinical human research evaluation.

Contents of the invention

In order to facilitate the detection of the degree of fusion of implants, the present invention provides an intelligent implant, system and method based on detection of fusion degree and temperature.

The technical solution adopted by the present invention to solve the above problems is:

The intelligent implant based on fusion degree and temperature detection includes an implant body, at least one ultrasonic device is arranged inside the implant body, and the ultrasonic device is used for transmitting and receiving ultrasonic waves, and the ultrasonic waves for transmitting and receiving For fusion and/or temperature detection.

Further, a MEMS circuit system is also included, and the MEMS circuit system is electrically connected with the ultrasonic device.

Further, 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 electrically connected in sequence, and the preamplifier circuit and the pulse excitation circuit are all connected to the ultrasonic device .

Further, the pulse excitation circuit is also connected with an analog switch.

Further, an isolation circuit is provided between the control circuit and the driving circuit.

Further, the ultrasonic devices are arranged in an array.

Further, the ultrasonic device is an ultrasonic piezoelectric sheet.

Further, the installation direction of the ultrasonic piezoelectric sheet is towards the detection area of the implant body, and the installation area of the ultrasonic piezoelectric sheet is consistent with the area of the detection area of the implant body.

The detection system includes a signal processing terminal and an intelligent implant based on fusion degree and temperature detection, and the signal processing terminal is used for fusion degree and/or temperature detection according to transmitted and received ultrasonic waves.

Further, 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.

The intelligent implant fusion degree detection method is applied to the detection system, including:

Step 1. After the smart implant is implanted in the body, the signal processing terminal records the received signal of the ultrasonic device;

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

Further, the step 1 also includes recording the transmission signal of the ultrasonic device, and the step 2 is specifically to judge the degree of fusion according to the amplitude Vi of the received signal and the amplitude of the transmitted signal, and the greater the amplitude difference, the higher the degree of fusion.

Further, before the step 1, step A is also included. Before the smart implant is implanted in the body, the signal processing terminal records the amplitude V0 of the ultrasonic reflection signal, and the step 2 specifically performs the fusion degree according to the ratio of Vi and V0. Judgment, the smaller the ratio, the higher the fusion degree.

Further, an analog switch is used to select the ultrasonic piezoelectric sheet for transmitting and receiving ultrasonic signals.

The intelligent implant temperature detection method is applied to the detection system, including:

Step 1. After the smart implant is implanted in the body, the signal processing terminal records the transmitted signal and received signal of the ultrasonic device;

Step 2. Judging the temperature of the implant according to the time difference between the transmitted signal and the received signal: the greater the time difference between the transmitted signal and the received signal, the higher the temperature.

Compared with the prior art, the present invention has the beneficial effect that: since the ultrasonic wave will be reflected on the heterogeneous surface, if the implant and the surrounding tissue are gradually fused, part of the ultrasonic wave can be transmitted into the surrounding tissue, and the amplitude of the reflected ultrasonic signal The higher the degree of fusion between the implant and the surrounding tissue, the more obvious the ultrasonic transmission phenomenon, and the lower the amplitude of the reflected ultrasonic signal. Therefore, the use of ultrasound to detect the fusion degree of the implant avoids the dependence on the doctor's experience, has high precision, reliable results, and no radiation hazard; the intelligent implant has a simple structure and is easy to use. In addition, the temperature of the implant can also be judged by using the propagation time of the ultrasonic wave, and then whether it is infected or not can be judged. Through the use of intelligent implants, the degree of implant healing can be detected and monitored in real time, and patients with poor healing can be detected, diagnosed, and treated early, so as to avoid missing the best healing time and reduce postoperative secondary surgery. Risk of surgery or delayed bone healing.

Description of drawings

Fig. 1 is a structural schematic diagram of an ultrasonic piezoelectric sheet and an implant body;

Fig. 2 is the structure diagram of MEMS circuit system and ultrasonic piezoelectric film;

Fig. 3 is the relationship diagram of the amplitude and fusion degree of received signal;

Fig. 4 is the relationship diagram of propagation time and temperature;

Fig. 5 is a structural schematic diagram of an ultrasonic piezoelectric sheet in an orthopedic screw;

Fig. 6 is a structural schematic diagram of the ultrasonic piezoelectric sheet in the fusion device;

Fig. 7 is a structural schematic diagram of the ultrasonic piezoelectric sheet in the bone plate;

Fig. 8 is a schematic diagram of the structure of the ultrasonic piezoelectric sheet in the hip joint prosthesis stem;

Fig. 9 is a structural schematic diagram of an orthopedic screw;

Figure 10 is a schematic structural view of the intervertebral fusion device implanted into the spine;

Figure 11 is a schematic structural view of the bone plate;

Fig. 12 is a schematic diagram of the structure of the hip joint prosthesis implanted in the body;

Fig. 13 is a schematic diagram of the structure of the shoulder joint prosthesis implanted in the body;

Fig. 14 is a schematic diagram of the structure of the ankle joint prosthesis implanted in the body;

Fig. 15 is a schematic diagram of the structure of the wrist prosthesis implanted in the body;

Fig. 16 is a schematic diagram of the structure of the knee prosthesis implanted in the body;

Figure 17 is a schematic structural view of the titanium mesh implanted into the spine;

18-19 are schematic diagrams of the fusion process of the intervertebral cage;

Reference signs: 1. Implant body, 2. Ultrasonic piezoelectric sheet 3. Screw hole.

detailed description

In order to make the object, technical solution and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with the examples. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

Example 1

As shown in Figure 1, the intelligent implant based on fusion degree and temperature detection includes an implant body 1, and at least one ultrasonic device is arranged inside the implant body 1, and the ultrasonic device is used for transmitting and receiving Ultrasound, transmitted and received for fusion and/or temperature detection.

Specifically, in this embodiment, the ultrasonic device uses an ultrasonic piezoelectric sheet 2, and several ultrasonic piezoelectric sheets 2 are arranged in an array. The same ultrasonic piezoelectric sheet 2 can be used for transmitting and receiving ultrasonic waves, or can be Different Ultrasonic Piezoelectric Sheets2. Applying pulse excitation to the ultrasonic piezoelectric film 2 can excite ultrasonic waves, and the ultrasonic reflected signal acts on the ultrasonic piezoelectric film 2 to generate electrical signals.

As shown in Figure 2, 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 electrically connected in sequence, and the preamplifier circuit and the pulse excitation circuit are all connected with each other. The ultrasonic piezoelectric sheet 2 is electrically connected. In order to avoid the interference of pulse excitation to the received signal, an isolation circuit is also set in the circuit.

Due to the diffusion angle of ultrasonic waves, in order to avoid the mutual interference caused by multiple ultrasonic piezoelectric sheets 2 working at the same time, an analog switch is set to control the ultrasonic piezoelectric sheets 2, so that it can realize time-sharing work, and at the same time, it can realize different Positional fusion and/or temperature detection. In this embodiment, the analog switch turns on different ultrasonic piezoelectric sheets 2 sequentially according to a preset sequence.

Example 2

This embodiment is described by taking the implant body 1 as an orthopedic screw as an example. The structure diagram of the orthopedic screw is shown in FIG. 9 . The orthopedic screw is an orthopedic implant commonly used in clinical practice. Bone screws are usually used for the fixation of internal fractures or dislocations, and the fixation of fractures is achieved by directly screwing into two different bone pieces or implants such as fixed bone plates. When performing fusion detection on it, it mainly performs fusion detection on the surrounding areas.

On the basis of Embodiment 1, in this embodiment, the array of ultrasonic piezoelectric sheets 2 is arranged circumferentially around the stud of the orthopedic screw to realize the detection of the degree of fusion around the stud. The cross-sectional view of the orthopedic screw is shown in Figure 5 Show. When the implant body 1 is an intramedullary nail or a dental implant nail, the arrangement of the ultrasonic piezoelectric sheet 2 array can refer to orthopedic screws.

Example 3

In this embodiment, the intervertebral fusion device with the implant body 1 as a square is illustrated as an example. The structural diagram of the intervertebral fusion device when it is implanted into the spine is shown in Figure 10. The intervertebral fusion device is used to rebuild the stability of the spine. One of the main components of the system, the fusion degree in the six directions of up, down, left, right, front and back needs to be detected when the fusion degree is detected.

On the basis of Example 1, six sets of ultrasonic piezoelectric sheet 2 arrays are arranged inside the intervertebral fusion cage, which are used to transmit ultrasonic waves in different directions. The cross-sectional view of the intervertebral fusion cage is shown in FIG. 6 . When the implant body 1 is an artificial vertebra or a solid titanium mesh, the arrangement of the array of ultrasonic piezoelectric sheets 2 can refer to the intervertebral fusion cage. The structure diagram of the titanium mesh implanted in the spine is shown in Figure 17.

Example 4

This embodiment takes the implant body 1 as a bone plate as an example for illustration. The structural diagram of the bone plate is shown in Figure 11. The bone plate is an internal fixation device for plate-shaped fractures with screw holes 3. It is often used clinically with bone screws or bone Use with silk. The fusion degree detection is mainly to detect the fusion degree between the bottom surface of the bone plate and the bone.

On the basis of Embodiment 1, an array of ultrasonic piezoelectric sheets 2 is provided on the bone plate for emitting ultrasonic waves downward. The cross-sectional view of the bone plate is shown in FIG. 7 .

Example 5

This embodiment is described by taking the implant body 1 as a hip joint prosthesis as an example. The structural diagram of the hip joint prosthesis after it is implanted in the body is shown in Figure 12. This embodiment is mainly used to detect the degree of fusion at the stem, so On the bone stem of the hip joint prosthesis, an array of ultrasonic piezoelectric sheets 2 for detection to the surroundings and an array of ultrasonic piezoelectric sheets for detection of the tail end of the bone handle are set. The vertical section of the bone handle is shown in Figure 8 . In order to detect the degree of fusion at the acetabular cup, an ultrasonic piezoelectric sheet 2 may also be arranged on the acetabular cup.

Other artificial joint prosthesis such as elbow joint prosthesis, wrist joint prosthesis, artificial intervertebral disc prosthesis, shoulder joint prosthesis, ankle joint prosthesis and knee joint prosthesis, etc., can also be equipped with ultrasonic devices at corresponding positions to achieve fusion detection , such as: the shoulder joint prosthesis can detect the fusion degree between the ball head and the humerus stem and the surrounding tissues, the ankle joint prosthesis can detect the fusion degree between the prosthesis and the tibia, and the wrist joint prosthesis can detect the fusion degree between the prosthesis and the carpus and radius. The fusion degree of the knee joint prosthesis can detect the fusion degree between the prosthesis and the femur and tibia. The specific setting method of the ultrasonic device is determined by the area to be detected, and will not be repeated here. 13 to 16 respectively show the structural schematic diagrams of the shoulder joint prosthesis, the ankle joint prosthesis, the wrist joint prosthesis and the knee joint prosthesis implanted in the body.

In any one of Embodiment 2 to Embodiment 5, in order to ensure the transmission distance of the ultrasonic wave, the array of ultrasonic piezoelectric sheets is arranged near the centerline of the implant body, such as the horizontal centerline and the vertical centerline.

Example 6

This embodiment provides a detection system, including a signal processing terminal and the intelligent implant based on fusion degree and temperature detection described in any of the above embodiments, and the signal processing terminal is used to perform fusion degree based on transmitted and received ultrasonic waves. and/or temperature detection.

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.

The intelligent implant fusion degree detection method is applied to the above-mentioned detection system, including:

Step 1. After the smart implant is implanted in the body, the signal processing terminal records the received signal of the ultrasonic device in real time;

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

The present invention provides two methods for judging the degree of implant fusion according to the amplitude Vi of the received signal:

Method 1: the step 1 also includes recording the transmission signal of the ultrasonic device; the step 2 is specifically to judge the degree of fusion according to the amplitude Vi of the received signal and the amplitude of the transmitted signal, and the larger the amplitude difference indicates the fusion of the implant The higher the degree. The greater the difference between the amplitude of the received signal and the amplitude of the transmitted signal, the less ultrasonic waves are reflected back. Therefore, the smaller the amplitude of the received signal, the higher the degree of fusion of the prosthesis. The relationship between the amplitude of the received signal and the degree of fusion is shown in Figure 3. This method is suitable for the case where the outer wall of the implant body is parallel to the ultrasonic piezoelectric sheet.

When the outer wall of the implant body is not parallel to the ultrasonic piezoelectric sheet, method 2 is adopted: before the step 1, step A is also included, and the amplitude V0 of the ultrasonic reflection signal is recorded before the smart implant is implanted in the body; Step 2 is specifically to judge the fusion degree according to the ratio of Vi and V0, the smaller the ratio, the higher the fusion degree.

f为不同植入物的融合度判定函数，该函数式可以通过有限元仿真或者实验得到。The relationship between the amplitude of the reflected signal and the degree of fusion can be expressed as:

f is a fusion degree judgment function of different implants, which can be obtained through finite element simulation or experiment.

Furthermore, the analog switch can also 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.

The intelligent implant temperature detection method is applied to the above detection system, including:

Step 1. After the smart implant is implanted in the body, the signal processing terminal records the transmitting and receiving signals of the ultrasonic transceiver device in real time;

Step 2. Judging the temperature of the implant according to the time difference between the transmitted signal and the received signal: the greater the time difference between the transmitted signal and the received signal, the higher the temperature of the implant. The higher the temperature, the longer the propagation time of ultrasonic waves, and the relationship between the transmission time and temperature is shown in Figure 4.

式中r为声压反射率，t为声压透射率，Z为声阻抗且Z＝ρC(ρ为介质的密度，C为超声波声速)，P_r为反射波声压，P₀为入射波声压，P_t为透射波声压，Z₁、Z₂分别为两种介质的声阻抗。The degree of fusion described in this application includes bone healing, fusion, and osseointegration of the implant-bone interface. Taking the osseointegration of the implant-bone interface as an example, there are three main processes in the process of osseointegration of the implant-bone interface. The first process: the interface between the implant and the bone is the interface gap, fibrous soft tissue or bone. The schematic diagram of the fusion between the intervertebral cage and the spine is shown in Figure 18-19. The larger the shaded area, the higher the degree of fusion. The principle that the present invention uses ultrasonic wave to detect is:

In the formula, r is the sound pressure reflectivity, t is the sound pressure transmittance, Z is the acoustic impedance and Z=ρC (ρ is the density of the medium, C is the ultrasonic sound velocity), P _r is the sound pressure of the reflected wave, and P ₀ is the incident wave Sound pressure, P _t is the sound pressure of the transmitted wave, Z ₁ and Z ₂ are the acoustic impedance of the two media respectively.

Suppose Z ₂ is the acoustic impedance of the implant body, and Z ₁ is the acoustic impedance of a certain substance in the contact area with the surface of the implant body (acoustic impedance of solid > acoustic impedance of muscle tissue > acoustic impedance of liquid > acoustic impedance of air ). When the implant body is not implanted in the body, the surface of the implant body is in contact with air. Assuming that the acoustic impedance of air is 1, the acoustic impedance of the implant body material is generally thousands of times that of air, so r≈1 , t≈0, that is, the ultrasonic wave is almost totally reflected. After the implant body is implanted in the body, if the implant body is not in contact with the bone, blood and other soft tissues will be filled in the non-contact area. At this time, the reflectivity of the ultrasonic wave is lower than that before the implantation, but it is still very low. Large, that is, the transmittance of ultrasonic waves is relatively small. When the implant body is in good contact with the bone and is gradually fused, as the cartilage continues to harden and Z1 increases, the ultrasonic reflectivity r decreases continuously, and the ultrasonic transmittance _t increases continuously. Therefore, the amplitude of the ultrasonic echo signal can be used to judge the fusion condition of the implant body.

Claims (15)

1. An intelligent implant based on fusion degree and temperature detection, comprising an implant body, characterized in that at least one ultrasonic device is arranged inside the implant body, and the ultrasonic device is used for transmitting and receiving ultrasonic waves, Transmitted and received ultrasound is used for fusion and/or temperature detection. 2 . The intelligent implant based on fusion degree and temperature detection according to claim 1 , further comprising a MEMS circuit system, and the MEMS circuit system is electrically connected to the ultrasonic device. 3. The intelligent implant based on fusion degree and temperature detection according to claim 2, wherein said MEMS circuit system comprises a preamplifier circuit, a filter circuit, an AD conversion circuit, a control circuit, The drive circuit and the pulse excitation circuit, the preamplifier circuit and the pulse excitation circuit are all connected with the ultrasonic device. 4. The intelligent implant based on fusion degree and temperature detection according to claim 3, wherein the pulse excitation circuit is also connected with an analog switch. 5. The intelligent implant based on fusion degree and temperature detection according to claim 3, wherein an isolation circuit is provided between the control circuit and the drive circuit. 6 . The intelligent implant based on fusion degree and temperature detection according to any one of claims 1 to 5 , wherein the ultrasonic devices are arranged in an array. 7. The intelligent implant based on fusion degree and temperature detection according to claim 6, wherein the ultrasonic device is an ultrasonic piezoelectric sheet. 8. The intelligent implant based on fusion degree and temperature detection according to claim 7, characterized in that, the arrangement direction of the ultrasonic piezoelectric sheet is towards the region to be detected of the implant body, and the ultrasonic piezoelectric sheet The setting area is consistent with the area of the implant body to be detected. 9. A detection system, characterized in that it comprises a signal processing terminal and the intelligent implant based on fusion degree and temperature detection according to any one of claims 1 to 8, the signal processing terminal is used for transmitting and receiving ultrasonic waves Perform confluence and/or temperature detection. 10 . The detection system according to claim 9 , wherein 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. 11 . 11. The intelligent implant fusion degree detection method, applied to the detection system as claimed in claim 9 or 10, is characterized in that, comprising: Step 1. After the smart implant is implanted in the body, the signal processing terminal records the received signal of the ultrasonic device; Step 2, judging the degree of fusion of the implant according to the amplitude Vi of the received signal. 12. The intelligent implant fusion degree detection method according to claim 11, characterized in that, said step 1 also includes recording the transmitted signal of the ultrasonic device, and said step 2 is specifically based on the amplitude Vi of the received signal and the transmitted signal The signal amplitude is used to judge the degree of fusion, and the greater the amplitude difference, the higher the degree of fusion. 13. The intelligent implant fusion degree detection method according to claim 11, characterized in that, before the step 1, step A is also included, before the intelligent implant is implanted in the body, the signal processing terminal records the ultrasonic reflection signal Amplitude V0, the step 2 is specifically to judge the degree of fusion according to the ratio of Vi and V0, the smaller the ratio, the higher the degree of fusion. 14. The method for detecting fusion degree of an intelligent implant according to any one of claims 11-13, characterized in that an analog switch is used to select ultrasonic piezoelectric sheets for transmitting and receiving ultrasonic signals. 15. The intelligent implant temperature detection method, applied to the detection system as claimed in claim 9 or 10, is characterized in that, comprising: Step 1. After the smart implant is implanted in the body, the signal processing terminal records the transmitted signal and received signal of the ultrasonic device; Step 2. Judging the temperature of the implant according to the time difference between the transmitted signal and the received signal: the greater the time difference between the transmitted signal and the received signal, the higher the temperature.

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