GB2621128A

GB2621128A - Implantable prosthetic sensing system with energy harvesting modules for automated determination of wear, infection, and micromotion and methods of using

Info

Publication number: GB2621128A
Application number: GB2211157.9A
Authority: GB
Inventors: James Morgan Oliver
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-07-30
Filing date: 2022-07-30
Publication date: 2024-02-07
Also published as: GB202211157D0

Abstract

The device disclosed herein claims a synovial joint replacement prosthesis comprising two support structures with a bearing component situated between the support structures. Within the prosthesis are sensors that measures various parameters such as, bearing wear sensors 5 for measuring the distance between two components, temperature sensors (16, Fig 4) measuring bodily tissue and fluid for determination of infection, and micromotion sensors 5 for determination of prosthesis-bone motion. A power system (11,14, Fig 4) comprising electronic circuitry, piezoelectric energy harvesting modules 7, and a battery utilises human kinetics and kinematics to power the system. The measurements are transmitted to a software application installed on a receiving module 6 and analysed for automated determination and notification of health or illness.

Description

Implantable prosthetic sensing system with energy harvesting modules for automated determination of wear, infection, and micromotion and methods of using the same This invention relates to a device for artificial replacement of a human synovial joint and automated determination of wear, infection, and micromotion.

A human synovial joint, such as the wrist, elbow, knee, hip and ankle can be severely damaged or diseased, such as with osteoarthritis. In these cases, portions of soft-and osseous-tissues may be completely removed including bone, cartilage, and ligament. A joint replacement prosthesis may then be implanted with the goal of replacing the damaged soft-and osseous-tissues for artificial reconstruction of the joint and restoration of normal biomechanical function. The patient may experience complications such as, accelerated wear of the prosthesis polymer bearing component, infection of the surrounding soft-and osseous-tissues, or prosthesis loosening from excessive micromotion. When these aforementioned complications occur, the entire implant is removed in favour of a new, more complex revision prosthesis leading to more extensive surgery, reduced biomechanical function, higher rates of complications, and greater risk to life.

The device disclosed herein claims a joint replacement prosthesis within a human joint that allows for measurement of temperature of bodily tissue and fluid for determination of infection, measurement of distance between two opposing, articulating components for determination of bearing component wear, and measurement of motion between the prosthesis-bone interfaces for determination of micromotion. A remote power system comprising electronic circuitry, piezoelectric energy harvesting modules, and battery utilises kinetics and kinematics generated by human movement to power the system. The aforementioned measurements are transmitted to a software application installed on a receiving interface and analysed for automated determination and notification of health or illness. Said translation of this measurement data to the receiving interface enables real-time feedback from the implant with graphical display and analyses.

Figure 1 depicts the implantable prosthetic system which has been surgically inserted into a human synovial joint as a joint replacement prosthesis. The assembly of the housing components are illustrated in the isometric view of Figure 2. According to the embodiment of the present disclosure, the prosthesis generally includes two support structures fixed to bone (1,3), between which a bearing component is enclosed (2). The bearing component has a fixed connection to one of these support structures (3) while it articulates against the separated medial and lateral surfaces of the opposing support structure (1) under human movement. The first support structure (1) is made from a non-metallic material (e.g., ceramic, pyrolytic carbon or a similar material), the second support structure (3) is made from a metallic material (e.g. cobalt-chromium, titanium alloy or a similar material), and the bearing component (2) is made from a polymer material (e.g. ultra-high molecular weight polyethylene or a similar material).

Figure 3 exemplifies the locations of the various hardware technologies embedded within the first support structure (1,10) of the implantable prosthetic system.

Embedded in the first support structure of the implant is an array of proximity sensors (6) which measure distance and/or displacement from the second support structure (3) based on wear of the bearing component (2), at different rotational angles and points of contact. The first support structure (1,10) is made from a non-metallic material (e.g., ceramic, pyrolytic carbon or a similar material) which enables signals from the wear sensors to pass through the non-metallic first support structure (1,10) and detect its distance and/or displacement from the metallic second support structure (3) based on wear of the polymer bearing component material.

With regard to the embodiment of wear sensor(s) (6) of the first support structure (1,10), the measurement of distance and/or displacement is assumed to be defined as centimetres (cm), millimetres (mm), micrometres (um), nanometres (nm) or any other related distance scale which can be converted to a metric of material wear. The non-limiting embodiment of this feature is related to quantitative measurements based on bearing component (2) wear The wear sensor aids the user in determining real time wear of the implantable prosthetic systems bearing component (2) to determine a boundary of device function and/or failure.

Additionally, connected through the first support structure of the implant (3,17) is an array of micromotion sensors (18) which measure motion and/or displacement of the first support structure (3,17) from the bone interface based on component loosening or poor fixation. The micromotion sensors (18) can either be connected to the first support structure by a flexible material which protrudes from the base (3,17) or inserted directly into the bone independent of connection to the first support structure. At the tip of each micromotion sensor (18) is a magnet which couples with a hall effect sensor or similar technology integrated into the electronic circuitry (14). The hall effect sensor or similar technology converts the locality of a magnetic field from the array of micromotion sensors (18) into a measure of distance and/or displacement With regard to the embodiment of micromotion sensor(s) (5) of the first support structure (1,4), the measurement of distance and/or displacement is assumed to be defined as centimetres (cm), millimetres (mm), micrometres (um), nanometres (nm) or any other related distance scale which can be converted to a metric of micromotion. The non-limiting embodiment of this feature is related to quantitative measurements based on micromotion between the first support structure (1,4) and its bone interface. The micromotion sensor aids the user in determining real time micromotion of the implantable prosthetic systems first support structure (2) to determine a boundary of device function and/or failure.

Embedded within the first support structure (1,10) is electronic circuitry (9), powered by a piezoelectric energy harvesting power source (7) and rechargeable batteries (8), which couple to the plurality of wear sensors (6) and micromotion sensors (5) wherein the electronic circuitry sustains (9) the measurements processes and transmits said data to a computer system configured to receive, display, and interpret the measurement data. Generation of power to the piezoelectric energy harvester(s) (7) is created from the transmission of force, movement, or friction by the human musculoskeletal system through pads (4) connected to the first support structure (1,10) which compresses the piezoelectric energy harvesting power source (7).

Figure 4 exemplifies the locations of the various hardware technologies embedded within the bearing component (2,11) and second support structure (3,17) of the implantable prosthetic system. Embedded within the bearing component (2,11) is a temperature sensor (16) which measures hotness and/or coolness of the biological environment within the human joint's synovial sac to indicate infection.

With regard to the embodiment of infection sensor(s) (16) of the device, the measurement of temperature is assumed to be defined as Fahrenheit (°F), Celsius (°C), Kelvin (K), Rankine (°R or °Ra) or any other related temperature scale which is converted to a metric of infection. The non-limiting embodiment of this feature is related to quantitative measurements of infection. The infection sensor (16) aids the user in determining real time temperature of the human joint's synovial fluid to indicate a boundary for user health and/or illness.

Additionally, connected through the second support structure of the implant (3,17) is an array of micromotion sensors (18) which measure motion and/or displacement of the second support structure (3,17) from the bone interface based on component loosening or poor fixation. The micromotion sensors (18) can either be connected to the second support structure by a flexible material which protrudes from the base (3,17) or inserted directly into the bone independent of connection to the second support structure. At the tip of each micromotion sensor (18) is a magnet which couples with a hall effect sensor or similar technology integrated into the electronic circuitry (14). The hall effect sensor or similar technology converts the locality of a magnetic field from the array of micromotion sensors (18) into a measure of distance and/or displacement With regard to the embodiment of micromotion sensor(s) (18) of the second support structure (3,17), the measurement of distance and/or displacement is assumed to be defined as centimetres (cm), millimetres (mm), micrometres (um), nanometres (nm) or any other related distance scale which can be converted to a metric of micromotion. The non-limiting embodiment of this feature is related to quantitative measurements based on micromotion between the second support structure (3,17) and its bone interface. The micromotion sensor aids the user in determining real time micromotion of the implantable prosthetic systems second support structure (3,17) to determine a boundary of device function and/or failure.

Embedded within the second support structure (3,17) is electronic circuitry (14), powered by a piezoelectric energy harvesting power source (12,13) and rechargeable batteries (15), which couple to the plurality of temperature sensors (16) and micromotions sensors (18) wherein the electronic circuitry sustains (14) the measurements processes and transmits said data to a computer system configured to receive, display, and interpret the measurement data. Generation of power to the piezoelectric energy harvester(s) (12,13) is created from the transmission of force, movement, or friction by the human musculoskeletal system from the second support structure (3,17) through the bearing component (2,11) which compresses the piezoelectric energy harvesting power source (12,13).

The converted metrics from the infection, wear, and micromotion sensors are transmitted to a receiving machine which may comprise a computer including a server computer, a client user computer, a personal computer (PC), a tablet PC, a laptop computer, a desktop computer, a control system, logic circuitry, a sensor system, an ASIC, an integrated circuit, a network router, switch or bridge, or any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that machine that the user will be able to relate to most easily. Real-time, graphical display through a proprietary software installed on the aforementioned machine or similar technology can analyse the data, present a graphical display of infection and wear, and determine a status workflow for health and function of the user.

While the present invention has been described with reference to particular embodiments, those skilled in the art will recognize that many changes may be made thereto without departing from the spirit and scope of the present invention. Therefore, it should be understood that this embodiment is merely illustrative of the principles and applications of the present invention and that numerous modifications may be made and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claim. Each of these embodiments and obvious variations thereof is contemplated as falling within the spirit and scope of the invention.

Claims

Claims 1 An implantable prosthetic system used to monitor the biological and artificial environment of an implanted human synovial joint comprising: two support structure components which are affixed to the ends of bone to form an articulating joint between a bearing component.electronic circuitry, piezoelectric energy harvesting transducers, and power sources coupled to a plurality of sensors where the electronic circuitry and power sources are housed in the implantable prosthetic system to power the sensing capabilities for monitoring of wear, infection, and micromotion resulting from the prosthetic system.
2 The prosthetic assembly of claim 1 where the first support structure is made from a non-metallic material (e.g., ceramic, pyrolytic carbon or a similar material), the second support structure is made from a metallic material (e.g. cobalt-chromium, titanium alloy or a similar material), and the bearing component which is made from a polymer material (e.g. ultra-high molecular weight polyethylene or a similar material).
3 The prosthetic assembly of claim 1 where an array of inductive proximity sensors is embedded within the non-metallic support structure to measure its distance from the opposing metallic support structure, used to determine wear of the polymer bearing component, and is referred to, herein, as the wear sensor.
4 The prosthetic assembly of claim 1 where a temperature sensor is embedded within the polymer bearing component, with an access hole, to measure hotness and coolness of the surrounding bodily tissues and fluids to determine the onset of infection, and is referred to, herein, as the infection sensor.
The prosthetic assembly of claim 1 where an array of magnetic antenna is connected with the bone-implant surface of each support structure and couple with a hall effect sensor, or similar technology, to detect the presence of a magnetic field and measure distance from the antennae and sensor to determine micromotion between the support structure-bone interfaces, and are referred to, herein, as micromotion sensors.
6 The prosthetic assembly of claim 1 where a printed circuit board with bluetooth unit transmits the measurements of claims 3,4,5 for analysing and graphically displaying the information obtained on a receiving interface.
A femoral prosthetic support structure component comprising: 7 The first support structure of claim 2 where the component is made from a non-metallic material (e.g., ceramic, pyrolytic carbon or a similar material) with an array of embedded inductive proximity sensors of claim 3 enable detection of the second support structure which is made a metallic material (e.g., cobalt-chromium, titanium alloy or a similar material).
8 The first support structure of claim 2 further including a medial surface and a lateral surface wherein the medial and lateral surfaces of the are configured to angles of rotational axes which couple to the polymer bearing component; wherein the medial and lateral rotational axes may differ in area, shape, or contour, and wherein the array of medial and lateral inductive proximity sensors of claim 3 are configured to measure distance from the opposing metallic support structure of claim 2 and couple to the electronic circuitry, piezoelectric energy harvesting transducers, and power sources of claim 1.
9 The array of medial and lateral inductive proximity sensors of claim 3 wherein the array of sensors may be non-symmetrical about a rotational axis wherein they may be configured for use in a left knee or right knee.
10. The first support structure of claim 2 further including an array of flexible magnetic antennae which couple to a hall effect sensor or similar technology of claim 5 which is embedded in the electronic circuitry of claim 1.
11 The first support structure of claim 2 further including a power source system comprising electronic circuitry, piezoelectric energy harvesting modules, and batteries of claim 1 utilising kinetics and kinematics generated by human movement to power the electronic systems of the support structures, in the first support structure of claim 2, the piezoelectric energy harvesting modules couple between the internal surface of metallic base plates and the non-metallic support structure; therein power sources are generated from the energy of force, movement, or friction generated between the aforementioned components.
A tibial prosthetic support structure component comprising: 12. The second support structure of claim 2 where the component is made from a metallic material (e.g. cobalt-chromium, titanium alloy or a similar material) in order for detection by an array of inductive proximity sensors.
13. The second support structure of claim 2 further including an array of flexible magnetic antennae which couple to a hall effect sensor or similar technology of claim 5 which is embedded in the electronic circuitry of claim 1.
14. The second support structure of claim 2 further including a power source system comprising electronic circuitry, piezoelectric energy harvesting modules, and batteries of claim 1 utilising kinetics and kinematics generated by human movement to power the electronic systems of the support structures. In the second support structure of claim 2, the piezoelectric energy harvesting modules couple between the internal surfaces of the polymer bearing component of claim 2 and second support structure. Therein, power sources are generated from the energy of force, movement, or friction generated between the aforementioned components.A tibial bearing prosthetic component comprising:
15. The polymer bearing component of claim 2 wherein a temperature sensor for measurement of temperature occurring within the environment of the joint for analysis of infection is encased within the bearing component.