SImOS: Smart Implants for Orthopaedics Surgery



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References about CMOSAIC:


6 October 2010: Mal au genou: on change tout !, TSR1 examines the prosthetic knee, and interviews several members of the SImOS project (In French, 20 mins)



What is SimOS


Out of the million of hip and knee prosthesis that are implanted each year in EU and US, none contain microchip and few are analysed based on motion analysis devices. During this project, we aim to develop a prototype system constituted of implanted sensors and electronics, external sensors and electronics and a remote device to measure the knee joint function in the application case of a total joint prosthesis (see illustration). While our overall objective is to propose systems that can be used with any existing joint prosthesis, this project will focus on a FIRST? knee joint prosthesis designed by one of the partner and produced by an industry also involved in the project. This project mainly aims to demonstrate the feasibility and the efficiency of our approach (implantation of sensors and fusion of distributed sensors), as well as to get the experience related to the packaging and implantation of the components.
Thus, the prototype will include numerous sensors to quantity the joint function in term of: 3D rotation, forces on the polyethylene insert, friction, loosening of the tibial prosthesis part and spatiotemporal parameters of gait.

To reach these objectives a balance between the implanted module, which should be minimal in size, number of components, power requirement and effect on the prosthesis function, and the external module, which is less constrained, will be found. The project is divided into five workpackages leaded each by one partners. The first one (WP1) will set the system configuration balancing the requirements of all partners.
For example, strain gauges and temperature sensors could be implanted to measure force and friction at the insert, accelerometers could be implanted to analyse vibration and thus estimate prosthesis loosening, magnets and magnetic sensors could be implanted and fused with external inertial sensors (accelerometers and gyroscopes) to measure 3D joint rotation and external inertial sensors could be used to estimate spatiotemporal parameters of gait. This workpackage will also define the configuration for the implanted and external electronics, as well as for the telemetry and communication task. The changes induced on the prosthesis function will also be evaluated and its accordance with existing norms and standards examined.
The second workpackage (WP2) will be devoted to the realisation and the testing of a large-scale SImOS demonstrator. This phase aims to validate the system configuration (WP1) and to provide first data to develop the analysis tools and adapt the surgical technique during WP3.
The third workpackage (WP3) aims to realize all the components required for the final SImOS prototype and to implant them in the prosthesis. During this phase, the analysis software will be improved and validated. Finally, during this phase the certifications and ethic committee agreements will be asked. During the workpackage 4 (WP4), the prototype will be implanted in a subject.
The system will be used during the surgery, during the rehabilitation and during many follow-up. Thus, this phase will assess the suitability and the efficiency of the proto