The project objective is to develop a diagnosis protocol together with an instrumented hip implant allowing the quantification of the anchorage of a prosthesis in order to:
early detect non-painful implant loosening;
avoid unnecessary implant-revision surgery;
a quantitative comparison of the anchorage of new implant designs.
This overall objective is translated in technical objectives:
a vibration protocol embedded in a dedicated software package;
biocompatible and hermetic packaging for long term implantation;
external unit for data reception, shaker control and implant powering; - transmission of the sensor data from the implant to the external unit; - all developments will strictly respect all ethical regulations.
The word "anchorage" refers in the biomedical field, to the old dream of the connection between a living organism and a prosthesis. One crucial problem is to estimate the mechanical and biological quality of the anchorage. Imaging techniques are currently used for the detection of prosthesis loosening without ascertaining confidently the onset of the loosening. The project STIMuLus focuses on the problem of the "loosening" of hip implants. By integrating a miniature accelerometer into the implant, the response of the implant to an imposed vibration is used, to monitor its fixation. A fixed prosthesis will form, together with the bone, a linear system. If this system is driven at a certain frequency, it will respond at that single frequency; however, when the prosthesis gets loose, the system will behave non-linear, with many harmonic components in the response signal. A dedicated electronic system must be developed to transfer the signals to a receiver, outside the patient's body. The STIMuLus project represents the developments of a sensor system to monitor the condition of an implant, integrating applied research in orthopaedics, electronics and biomechanics. The research carried out in this project is very advanced, and will show benefits both for the public health and for the industry. Accurate and reliable loosening monitoring will reduce health care service costs by reducing of late revision surgery, associated to significant reduction of the bone stock. Patients will see fewer repeated implantation and clinicians obtain a reliable tool for the diagnosis of loosening and to quantitatively evaluate new implant designs. The implant developed in the context of this project is believed to represent, because of its monitoring capabilities, the first of a totally new generation.
Funding SchemeCSC - Cost-sharing contracts
14201 Herouville St. Clair
CT2 7NT Canterbury