Smart Orthopedic Implants Powered by Acoustic Power Transmission – PiezoKnee

Smart orthopedic implants open up very interesting prospects, particularly for the improvement of post-surgical follow-up. However, nowadays, the technologies available are not adapted to power fully-metallic prostheses used in orthopedics. This project aims to exploit a power transmission solution based on acoustic waves to transmit power in a knee implant. A knee joint model will be developed using new statistical modeling methods integrating acoustic parameters. In addition, the admissible input power levels will be studied to limit the physical mechanisms (thermal, cavitations) and remain below the values set by the standards and used by the commercial ultrasound equipments. This model and the input data will then be used to design, optimize the power transmission solution with both analytical and multi-physics Finite Element modeling methods for a tibial knee implant embedding piezoelectric transducers. We expect the acoustically powered system to receive an amount of electrical power within the 1 mW to 10 mW range at the receiver side while being compliant with medical standards and using commercial ultrasound probes at the transmitter side. Prototypes will be assembled and tested first on five knee phantoms elaborated within the project and then on three cadaveric specimens at the anatomical laboratory of the Brest CHRU. The proofs of concept (PoCs) will then allow to power a new generation of smart orthopaedic implants embedding sensors, that are more robust and more reliable, facilitating industrialization and ultimately allowing better clinical management.