The researchers at Hong Kong Polytechnic University (PolyU) have developed novel fibre optic microsensors for medical surveillance inside the human body.

Led by professor Hwa-yaw Tam, the research team designed the optical fibre sensors to be biocompatible, flexible and sensitive to minute pressure changes inside the human body.

The sensors can be used for medical applications such as smart cochlear implantation, bone fracture recovery monitoring, or navigation monitoring in cardiac catheterisation.

They are developed using Zeonex, an advanced plastic material that addresses problems associated with glass and traditional plastic.

Tam said: “The new plastic sensors are humidity insensitive, supple and shatter-resistant. They are also chemically inert, biocompatible, and can be made super tiny in size. These unique features make the sensors ideal for integration with medical implants.

“The new plastic optical fibre sensors can detect extremely subtle changes even of a difference smaller than 1 per cent of atmospheric pressure-sensitive enough to measure pressure inside the lungs while breathing, which changes by just a few kilopascals.”

The team added a side hole that runs parallel with the light transmission path inside the optical fibre to enhance the sensitivity of the new sensor.

According to professor Tam, the sensors would enable new applications for medical monitoring inside the human body that are not previously available.

The PolyU research team is currently working with scientists from Australian and Japanese universities to develop several sensors for medical monitoring applications.

A smart cochlear implant featuring compact sensors from PolyU is capable of providing critical information about location and force to surgeons in real-time during the implantation.

The in vitro testing of the smart cochlear implant is planned to start at the University of Melbourne and the Royal Victorian Eye and Ear Hospital.

Furthermore, the PolyU team is working with researchers from Monash University to integrate fibre sensors in orthopaedic implants for monitoring bone fracture recovery.

Tam added: “We also seek to develop a sensing network that integrates our sensors with emerging technologies like the wireless Internet-of-Things.

“The sensing network would be able to give a comprehensive and precise picture of changes inside the human body, thus helping patients around the world via technological innovation.”