Self-powered Implants For Injured Knees

Tag : Thick Felt

As news of Tiger Woods' knee injury hits the headlines, aresearcher at the University of Southampton has developed a newself-powered sensor to monitor progress during knee operations.

As part of his final year project in his Masters degree inElectromechanical Engineering, which he studied at the University'sSchool of Electronics and Computer Science (ECS), Fauzan Baharudinexplored the potential for the use of thick film technology in thedevelopment of medical sensors which could be embedded in the kneeduring surgery.

This new sensor, called Serial In-vivo Transducer (SIT), which usesthick film technology, could measure tendon force during AnteriorCruciate Ligament (ACL) reconstruction.

The ACL is the most commonly injured ligament and is commonlydamaged by athletes, in fact it is reported that this is theligament associated with Tiger Woods' injury.

Fauzan's project was supervised by Professor Neil White at ECS,who, in 1991 developed thick film piezoelectric material which madeit possible to produce a sensor which could power itself if it wereinstalled in a device that vibrates and would be ideal forappliances where physical connections to the outside world weredifficult.

Professor White said: 'Although this work is still in its infancy,our earlier research in thick-film sensors has shown that it isfeasible to apply the technology to medical applications such asprosthetic hands. We have also shown that it is possible to harvestenergy from the human body using piezoelectric materials and theknee is subjected to very high levels of force during everydayactivities. It therefore seems logical to combine the twoapproaches to deliver a new type of embedded, self-powered sensors

In Fauzan's project entitled Assessing the use of thick-filmtechnology in knee surgery: along with energy harvesting in-vivo,he has also incorporated some of this energy harvesting capabilityinto SIT which means that it will be self-powered.

'I chose knee surgery because this has been very little researchcarried out in this field and I felt a self-powered device couldwork well in the knee,' he said.

Before developing SIT, Fauzan reviewed the existing devices in thisfield and concluded that due to its flexibility in fabrication, lowcapital cost, fast lead time and its suitability for use in thebody, thick film technology is the best solution for ACL surgery.Assessment of the energy harvesting feature revealed that thedevice could produce more than enough energy to power itself.

'It remains a mystery to me, given how common knee injuries areamong athletes, that devices like ours have not been developedbefore now,' said Fauzan. 'A sensible assumption for this is thatthick film technology does not reach medical researchers as quicklyas it does within the microelectronics community hence the delay inrealising the huge potential in developing in vivo transducers.'

SOUTHAMPTON UNIVERSITY
Highfield
Southampton
SO17 1BJ
http://www.soton.ac.uk