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 instruments, and provides an intelligent implant based on fusion degree and temperature detection in order to detect the fusion degree and/or temperature of the implant. 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 is used for judging the implant fusion degree according to the amplitude of ultrasonic waves. The intelligent implant temperature detection method judges the temperature of the implant according to the propagation time of ultrasonic waves. The method is convenient for detecting the fusion degree and/or the temperature of the implant and has 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 instruments, in particular to an intelligent implant, a system and a method based on fusion degree and temperature detection.

Background

The orthopedic implant products mainly comprise spine products, trauma products, artificial joint products, neurosurgery products (skull repairing titanium nets and skull bone fracture plates), thoracic surgery orthopedic products (such as sternum internal fixation implants, costal internal fixation implant products and the like) and the like. Common orthopedic implants include intervertebral fusion device, orthopedic bone fracture plate, orthopedic nail-rod fixing system (such as posterior spinal pedicle screw fixing system, anterior spinal nail-rod fixing system, etc., various types), orthopedic nail-plate system, hip joint prosthesis, knee joint prosthesis, artificial vertebral body, intramedullary nail, elbow joint prosthesis, wrist joint prosthesis, shoulder joint prosthesis, ankle joint prosthesis, screw, titanium mesh, orthopedic fixing needle, orthopedic fixing cable, orthopedic fixing rivet implant, orthopedic external fixing bracket implant (the nail and needle of the fixing bracket are implants, the connecting rod is 2 types of medical instruments), orthopedic personalized customization implant, orthopedic tumor implant product, orthopedic implant gasket, etc., and the types of orthopedic implants include but are not limited to the above product types and categories. When the implant is implanted in vivo, a higher degree of fusion with the surrounding tissue indicates better patient recovery. The fusion tests described in this patent include bone healing, fusion, and osteointegration at the orthopedic implant-bone interface. The biomechanical properties of the endophyte-bone interface are the determining factor in maintaining endophyte stability. Good endosteal-osseointegration is mainly manifested by intimate contact of mature bone tissue with the endosteal interface and mechanical locking, and is dependent on the ratio of bone tissue to endosteal contact. The long-term stability of the prosthesis after implantation depends on the quality and quantity of the osteointegration at the endoprosthesis-bone interface. Osseointegration depends on the regeneration of bone tissue at the prosthesis-bone interface. The osteointegration of the endophyte-bone interface mainly relates to artificial joint prosthesis, oral implant, screw, pedicle screw, interbody fusion cage, artificial centrum and the like.

In the prior art, an operation exploration mode and imaging detection (X-ray examination, CT tomography, nuclear magnetic resonance and the like) are mainly adopted when the fusion degree of the implant is detected. The operation exploration mode is only suitable for a few patients with revision operations due to the limitation of ethics; meanwhile, deep structures and healing conditions cannot be observed due to the limited visual field of the surgical exploration. The imaging detection is lack of uniform quantitative standard, and the consistency is poor; the patient needs to return to the hospital for examination for many times, and the time and the economic cost are high; radiation hazard exists; and cannot be monitored in real time. In addition, there is a method of killing animals and taking samples for Micro-CT, biomechanics, electron microscopy, histological morphology, histomorphometry, bone density, etc., but this method is not suitable for clinical human body research and evaluation.

Disclosure of Invention

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

The technical scheme adopted by the invention for solving the problems is as follows:

intelligent implant based on degree of fusion and temperature detect, including the implant body, the inside of implant body is provided with at least one ultrasonic device, ultrasonic device is used for launching and receiving the ultrasonic wave, and the ultrasonic wave of launching and receiving is used for degree of fusion and/or temperature detect.

Further, MEMS circuitry is included, the MEMS circuitry being electrically connected to the ultrasound device.

Furthermore, the MEMS circuit system comprises a pre-amplification 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, wherein the pre-amplification circuit and the pulse excitation circuit are both connected with the ultrasonic device.

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

Furthermore, an isolation circuit is arranged between the control circuit and the drive circuit.

Further, the ultrasonic devices are arranged in an array.

Further, the ultrasonic device is an ultrasonic piezoelectric sheet.

Furthermore, the setting direction of the ultrasonic piezoelectric sheet faces to the region to be detected of the implant body, and the setting area of the ultrasonic piezoelectric sheet is consistent with the area of the region to be detected of the implant body.

The detection system comprises a signal processing terminal and an intelligent implant based on fusion degree and temperature detection, wherein the signal processing terminal is used for detecting the fusion degree and/or the temperature 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 a detection system and comprises the following steps:

step 1, after the intelligent implant is implanted into a body, a signal processing terminal records a received signal of an ultrasonic device;

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

Further, the step 1 further includes recording the transmission signal of the ultrasonic device, and the step 2 specifically performs fusion degree judgment according to the amplitude Vi of the received signal and the amplitude of the transmission signal, and the larger the amplitude difference is, the higher the fusion degree is.

Further, step a is further included before step 1, before the intelligent implant is implanted into a body, a signal processing terminal records the amplitude V0 of the ultrasonic reflection signal, and step 2 specifically performs fusion degree judgment according to the ratio of Vi and V0, wherein the smaller the ratio, the higher the fusion degree is.

Further, the analog switch is used to select the ultrasonic piezoelectric sheet that transmits and receives the ultrasonic signal.

The intelligent implant temperature detection method is applied to a detection system and comprises the following steps:

step 1, after the intelligent implant is implanted into a body, a signal processing terminal records a transmitting signal and a receiving signal of an ultrasonic device;

step 2, judging the temperature of the implant according to the time difference between the transmitting signal and the receiving signal: the greater the time difference between the transmitted and received signals, the higher the temperature.

Compared with the prior art, the invention has the beneficial effects that: because the ultrasonic wave can be reflected on the heterogeneous surface, if the implant and the surrounding tissues are gradually fused, part of the ultrasonic wave can be transmitted into the surrounding tissues, and the amplitude of the reflected ultrasonic wave signal is correspondingly reduced; the higher the fusion degree of the implant and the surrounding tissues is, the more obvious the transmission phenomenon of the ultrasonic wave is, and the lower the amplitude of the reflected ultrasonic wave signal is. Therefore, the ultrasonic wave is adopted to detect the fusion degree of the implant, so that the dependence on the experience of a doctor is avoided, the precision is higher, the result is reliable, and no radiation hazard is caused; the intelligent implant is simple in structure and convenient to use. In addition, the propagation time of the ultrasonic wave can be used for judging the temperature of the implant, and further judging whether the implant is infected. The degree of the healing of the implant can be detected and monitored in real time through the use of the intelligent implant, the patient with poor healing degree is subjected to early discovery, early diagnosis and early treatment, the optimal healing time is prevented from being missed, and the risk of delaying the postoperative secondary operation or bone healing of the patient is reduced.

Drawings

FIG. 1 is a schematic structural view of an ultrasonic piezoelectric plate and an implant body;

FIG. 2 is a schematic structural diagram of an MEMS circuit system and an ultrasonic piezoelectric plate;

FIG. 3 is a graph of amplitude of a received signal versus a degree of fusion;

FIG. 4 is a graph of travel time versus temperature;

FIG. 5 is a schematic structural diagram of an ultrasonic piezoelectric plate in an orthopedic screw;

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

FIG. 7 is a schematic structural view of an ultrasonic piezoelectric plate in the bone plate;

FIG. 8 is a schematic structural view of an ultrasonic piezoelectric patch in a hip joint prosthesis stem;

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

FIG. 10 is a schematic view of an intervertebral cage as implanted in the spine;

FIG. 11 is a schematic view of the bone plate configuration;

FIG. 12 is a schematic view of the hip prosthesis after implantation in vivo;

FIG. 13 is a schematic structural view of the shoulder joint prosthesis after implantation in the body;

FIG. 14 is a schematic view showing a configuration after implantation of the ankle prosthesis in vivo;

FIG. 15 is a schematic structural view of the wrist prosthesis after implantation in the body;

FIG. 16 is a schematic view of the knee joint prosthesis after implantation in vivo;

FIG. 17 is a schematic view of a titanium mesh implanted in the spine;

fig. 18-19 are schematic views of a procedure for fusion of the intersomatic cage;

reference numerals: 1. implant body, 2, ultrasonic wave piezoelectric plate 3, screw.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Example 1

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

Specifically, in this embodiment, the ultrasonic device employs the ultrasonic piezoelectric patches 2, the ultrasonic piezoelectric patches 2 are arranged in an array, and the same ultrasonic piezoelectric patch 2 may be used for transmitting and receiving ultrasonic waves, or different ultrasonic piezoelectric patches 2 may be used. The ultrasonic wave can be excited by applying pulse excitation to the ultrasonic piezoelectric sheet 2, and the ultrasonic wave reflection signal acts on the ultrasonic piezoelectric sheet 2 to generate an electric signal.

As shown in fig. 2, the MEMS circuit system includes a preamplifier circuit, a filter circuit, an AD converter circuit, a control circuit, a driver circuit, and a pulse driver circuit, which are electrically connected in sequence, and both the preamplifier circuit and the pulse driver circuit are electrically connected to the ultrasonic piezoelectric sheet 2. In order to avoid the interference of the pulse excitation to the received signal, an isolation circuit is also arranged in the circuit.

Because the ultrasonic waves have a diffusion angle, in order to avoid the interference caused by the simultaneous operation of the plurality of ultrasonic piezoelectric sheets 2, an analog switch is arranged to control the ultrasonic piezoelectric sheets 2, so that the ultrasonic piezoelectric sheets can realize time-sharing operation, and the fusion degree and/or temperature detection at different positions can also be realized. In the present embodiment, the analog switch sequentially turns on the different ultrasonic piezoelectric sheets 2 in accordance with a preset sequence.

Example 2

In the embodiment, the implant body 1 is taken as an orthopedic screw, and a structural schematic diagram of the orthopedic screw is shown in fig. 9, and the orthopedic screw is an orthopedic implant commonly used for fixation in clinic. Bone screws are commonly used for the fixation of internal fractures or dislocations by screwing directly into two different bone pieces or into an implant such as a fixation plate. When the fusion degree detection is carried out on the fusion degree detection, the fusion degree detection is mainly carried out on the periphery.

On the basis of embodiment 1, in the present embodiment, an array of ultrasonic piezoelectric sheets 2 is arranged around the circumference of a stud of an orthopedic screw to realize detection of fusion degree around the stud, and a cross-sectional view of the orthopedic screw is shown in fig. 5. When the implant body 1 is an intramedullary nail or a dental implant nail, the arrangement mode of the array of the ultrasonic piezoelectric patches 2 can refer to orthopedic screws.

Example 3

In the present embodiment, the intervertebral cage in which the implant body 1 is a square block is taken as an example for explanation, a structural schematic diagram of the intervertebral cage when being implanted into the spine is shown in fig. 10, the intervertebral cage is one of main components for reconstructing the stability of the spine, and when detecting the fusion degree of the intervertebral cage, the fusion degrees in the up, down, left, right, front and back six directions need to be detected.

In example 1, six groups of ultrasonic piezoelectric sheets 2 are arranged in the intervertebral cage, and each group is used for emitting ultrasonic waves in different directions, and a cross-sectional view of the intervertebral cage is shown in fig. 6. When the implant body 1 is an artificial vertebral body or a solid titanium mesh, the arrangement mode of the array of the ultrasonic piezoelectric sheets 2 can refer to an intervertebral fusion device, and the structural schematic diagram of the titanium mesh when being implanted into the spine is shown in fig. 17.

Example 4

In the embodiment, the implant body 1 is taken as an example of a bone fracture plate, the structure of which is schematically shown in fig. 11, and the bone fracture plate is a plate-shaped fracture internal fixation device with screw holes 3, and is usually used in combination with bone screws or bone wires clinically. When the fusion degree is detected, the fusion degree between the bottom surface of the bone fracture plate and the bone is mainly detected.

In example 1, an array of ultrasonic piezoelectric plates 2 is provided on a bone plate for emitting ultrasonic waves downward, and the bone plate is shown in a cross-sectional view in fig. 7.

Example 5

In the present embodiment, the implant body 1 is taken as an example of a hip joint prosthesis, a schematic structural diagram of the hip joint prosthesis after being implanted into a body is shown in fig. 12, and the present embodiment is mainly used for detecting the fusion degree at a bone stem, so that an ultrasonic piezoelectric sheet 2 array for detecting the periphery and an ultrasonic piezoelectric sheet array for detecting the tail end of the bone stem are arranged on the bone stem of the hip joint prosthesis, and a cross-sectional view of the vertical part of the bone stem is shown in fig. 8. In order to detect the fusion degree at the acetabular cup, an ultrasonic piezoelectric sheet 2 can also be arranged on the acetabular cup.

Other artificial joint prostheses such as elbow joint prostheses, wrist joint prostheses, artificial intervertebral disc prostheses, shoulder joint prostheses, ankle joint prostheses, knee joint prostheses and the like can also be provided with ultrasonic devices at corresponding positions to realize fusion degree detection, such as: the shoulder joint prosthesis can detect the fusion degree between the ball head and the surrounding tissue, the humerus handle and the surrounding tissue, the ankle joint prosthesis can detect the fusion degree between the prosthesis and the tibia, the wrist joint prosthesis can detect the fusion degree between the prosthesis and the carpus and the radius, and the knee joint prosthesis can detect the fusion degree between the prosthesis and the thighbone and the tibia. The specific arrangement of the ultrasonic device is determined by the region to be detected, and will not be described herein. Fig. 13 to 16 show the respective structures of the shoulder joint prosthesis, the ankle joint prosthesis, the wrist joint prosthesis and the knee joint prosthesis after being implanted in vivo.

In any one of embodiments 2 to 5, in order to ensure the transmission distance of the ultrasonic wave, the ultrasonic piezoelectric sheet array is disposed on the implant body near a central line, such as a transverse central line and a vertical central line.

Example 6

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

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 detection system and comprises the following steps:

step 1, after the intelligent implant is implanted into a body, a signal processing terminal records a received signal of an ultrasonic device in real time;

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

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

the method comprises the following steps: the step 1 also comprises recording the emission signal of the ultrasonic device; and step 2, specifically, fusion degree judgment is carried out according to the amplitude Vi of the received signal and the amplitude of the transmitted signal, and the larger the amplitude difference is, the higher the fusion degree of the implant is. The larger the difference between the amplitude of the received signal and the amplitude of the transmitted signal is, the less the ultrasonic waves are reflected, so that the smaller the amplitude of the received signal is, the higher the prosthesis fusion degree is. The amplitude of the received signal is related to the degree of fusion as shown in fig. 3. This 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, adopting a method 2: step A, recording the amplitude V0 of an ultrasonic reflection signal before the intelligent implant is implanted into a body; and 2, specifically, the fusion degree is judged according to the ratio of Vi and V0, and the fusion degree is higher when the ratio is smaller.

The amplitude of the reflected signal versus the degree of fusion can be expressed as:

f is a fusion degree judging function of different implants, and the function can be obtained through finite element simulation or experiments.

Furthermore, an analog switch can be used for selecting the ultrasonic piezoelectric sheets for transmitting and receiving ultrasonic signals, so that fusion degree detection of different positions of the intelligent implant is realized.

The intelligent implant temperature detection method is applied to the detection system and comprises the following steps:

step 1, after the intelligent implant is implanted into a body, a signal processing terminal records a transmitting signal and a receiving signal of an ultrasonic receiving and transmitting device in real time;

step 2, judging the temperature of the implant according to the time difference between the transmitting signal and the receiving signal: a larger time difference between the transmitted and received signals indicates a higher implant temperature. The higher the temperature, the longer the propagation time of the ultrasonic wave, and the relationship between the propagation time and the temperature is as shown in fig. 4.

The fusion degree described in the present application includes bone healing, fusion and osteointegration at the implant-bone interface, and taking the osteointegration at the implant-bone interface as an example, there are three main processes in the process of osteointegration at the implant-bone interface: the interface between the implant and the bone is an interface space, fibrous soft tissue or bone, and the intervertebral cage and the spine are fused schematically as shown in fig. 18-19, with a greater area of the shaded portion indicating a higher degree of fusion. The principle of the invention for detecting by using ultrasonic waves is as follows:

where r is sound pressure reflectance, t is sound pressure transmittance, Z is acoustic impedance, Z = ρ C (ρ is density of medium, C is ultrasonic sound velocity), and P _r Is the sound pressure of the reflected wave, P ₀ Is incident wave sound pressure, P _t Is transmitted wave sound pressure, Z ₁ 、Z ₂ Respectively, the acoustic impedances of the two media.

Suppose Z ₂ Acoustic impedance of the body of the implant, Z ₁ Is prepared by reacting withThe acoustic impedance of a substance in the contact area of the surface of the implant body (solid acoustic impedance > acoustic impedance of muscle tissue > acoustic impedance of liquid > acoustic impedance of air). When the implant body is not implanted in the body, air is in contact with the surface of the implant body, and assuming that the acoustic impedance of the air is 1, the acoustic impedance of the material of the implant body is generally thousands of times that of the air, so r is about 1,t is about 0, namely, the ultrasonic wave is almost totally reflected. When the implant body is implanted in the body, if the implant body is not in contact with the bone, blood and other soft tissue will fill in the non-contact area, and the reflectivity of the ultrasound waves is reduced compared to that before the implant, but is still large, i.e. the transmission of the ultrasound waves is relatively small. Z is caused by continuous hardening of cartilage when the implant body is in good contact with the bone and gradually fuses ₁ The ultrasonic reflectivity r is reduced and the ultrasonic transmissivity t is increased. Therefore, the fusion condition of the implant body can be judged by the amplitude of the ultrasonic echo signal.

Claims (15)

1. Intelligent implant based on fusion degree and temperature detection, including the implant body, its characterized in that, the inside of implant body is provided with at least one ultrasonic device, ultrasonic device is used for transmission and receiving ultrasonic wave, and the ultrasonic wave of transmission and receipt is used for fusion degree and/or temperature to detect.

2. The fusion and temperature detection based smart implant of claim 1, further comprising MEMS circuitry, the MEMS circuitry being electrically connected to the ultrasound device.

3. The fusion degree and temperature detection based smart implant according to claim 2, wherein the MEMS circuit system comprises a pre-amplification 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 pre-amplification circuit and the pulse excitation circuit are both connected with the ultrasonic device.

4. The fusion and temperature detection based smart implant of claim 3, wherein an analog switch is further connected to the pulse excitation circuit.

5. The fusion and temperature detection based smart implant of claim 3, wherein an isolation circuit is provided between the control circuit and the driving circuit.

6. The smart implant based on fusion and temperature detection according to any one of claims 1 to 5, wherein the ultrasonic devices are arranged in an array.

7. The smart implant based on fusion and temperature detection as claimed in claim 6, wherein the ultrasonic device is an ultrasonic piezoelectric sheet.

8. The intelligent implant based on fusion degree and temperature detection is characterized in that the ultrasonic piezoelectric sheet is arranged in a direction facing to the region to be detected of the implant body, and the area of the ultrasonic piezoelectric sheet is consistent with the area of the region to be detected of the implant body.

9. Detection system, characterized in that it comprises a signal processing terminal for fusion and/or temperature detection based on transmitted and received ultrasound waves and a smart implant based on fusion and temperature detection according to any one of claims 1 to 8.

10. The detection system according to claim 9, wherein the signal processing terminal performs the implant fusion degree determination according to the amplitude of the ultrasonic wave and performs the implant temperature determination according to the propagation time of the ultrasonic wave.

11. The intelligent implant fusion degree detection method is applied to the detection system according to claim 9 or 10, and is characterized by comprising the following steps:

step 1, after the intelligent implant is implanted into a body, a signal processing terminal records a received signal of an ultrasonic device;

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

12. The method for detecting fusion degree of smart implant according to claim 11, wherein the step 1 further comprises recording the transmission signal of the ultrasonic device, and the step 2 is to perform fusion degree judgment according to the amplitude value Vi of the received signal and the amplitude value of the transmission signal, wherein the fusion degree is higher if the amplitude value difference is larger.

13. The method for detecting fusion degree of smart implant according to claim 11, wherein step 1 is preceded by a step a, before the smart implant is implanted into the body, the signal processing terminal records the amplitude V0 of the ultrasonic reflection signal, and step 2 is specifically to perform fusion degree judgment according to the ratio of Vi and V0, and the fusion degree is higher when the ratio is smaller.

14. The intelligent implant fusion degree detection method according to any one of claims 11 to 13, wherein an analog switch is used to select the ultrasonic piezoelectric sheet that transmits and receives the ultrasonic signal.

15. The smart implant temperature detection method applied to the detection system according to claim 9 or 10, comprising:

step 1, after the intelligent implant is implanted into a body, a signal processing terminal records a transmitting signal and a receiving signal of an ultrasonic device;

step 2, judging the temperature of the implant according to the time difference between the transmitting signal and the receiving signal: the greater the time difference between the transmitted and received signals, the higher the temperature.

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