Wireless microfluidic force sensors for orthopaedic surgery and telemetry

The number of hip replacements being performed globally is increasing significantly. An ageing population means that the number of hip arthroplasties is increasing, as is the number of failures, putting a great strain on public health infrastructure. At the same time, lifestyle changes have led to these procedures now being performed in a much younger cohort of patients, with typical lifespans of implants being 15 to 20 years primarily due to wear. A major cause for this wear and premature implant failure is eccentric loading due to inappropriate positioning which further necessitates expensive and difficult revision surgery. Currently, implant positioning is performed using anatomical landmarks, relying heavily on the surgeon's skill, as there is no objective method of measuring the forces in the hip to guide the optimal positioning of the implant. This proposal is aimed at solving this unmet clinical need by delivering wireless, implantable and conformable force sensors that can be integrated within current hip replacement prostheses to give accurate force readings from the joint during surgery, in order to minimize failure rates and improve patient outcome and care. This will be achieved through a novel microfluidic-based capacitive force sensing technology recently pioneered by the PI. These force sensors are soft and biocompatible, and they can operate in the limited space and challenging mechanical environment of the hip joint. However, these sensors currently have to be physically wired to external data acquisition modules. This arrangement is not optimal for use in a surgical setting. Therefore, there is an urgent need to make these sensors wireless in order to be compatible with surgical practice. The goal of this project is to incorporate wireless telemetry into our intraoperative force sensors, thereby enabling our technology to progress towards regulatory approval, and bringing us closer to first-in-human trials.