Introduction It’s a part of an electronic prototype that operate in MICS band Used to transfer information's regarding the patient during and after the surgery It has an implantable platform and an external base station It has a communication range of 2m

Block Diagram

Sensor Platform Main Components:  A wireless transceiver  Microcontroller  Capacitive power module  Antenna

Transceiver ZL70101 Designed for medical applications Low power consumption High data rate up to 800 Kb/sec

Microcontroller MSP430F2132 Small size Low power consumption 10 bit A-D converter In built temperature sensor Used to configure wireless transceiver and respond to user commands

Power module and Antenna Stored energy in 3 parallel 220mF EDLC Antenna used is printed circuit board antenna

Base Station Main Components:  2.45GHz transmitter  A wireless Transceiver  Microcontroller (MSP430F1611)  Antenna

How It Works? The sensor platform operates in two modes a sleep mode and an active mode The communication is initialized by transmitting an ook wake up signal via 2.45 GHz transmitter Communication in MICS band in half duplex communication link The sensor platform sends response packets after receiving a request from the base station

Functionality Tests Temperature sensor accuracy Power Consumption Communication range

Temperature sensor accuracy The internal sensor is compared with an external sensor A thermocouple is taken as reference All are subjected to temperature variations Measurements are taken at intervals

Result

Communication Range The sensor platform is placed at increasing distance from the base station The base station tries to initiate and maintain wireless link each time Number of successful connections were noted

Result 100% reliable in the targeted range 92% reliable in 2-6 m

Power Consumption The average power consumption of the sensor platform is measured in two modes Multimeter measures supply current at 3v Averaged it over a period of 10 minutes in both the modes

Result In sleep mode sensor platform drew an average current of.128 mA resulting in.654mW power consumption In active mode current drawn was 5.194mA resulting in mW power consumption

Advantages Reduced risk of interferences Low power consumption Small size

Applications Mainly used in scoliosis correction Used in medical applications

Conclusion With the advancement in wireless technology it is possible to operate wireless implants for longer period. The designed prototype is found to be efficient and has reduced the risk of scoliosis surgery.

References Base Paper: “Wireless implantable sensor platform ” Daniel Zbinden, Edmond Lou, Nelson Durdle,2010 IEEE. Y.Cortel, J Dubousset and m.Guillaumat, “New universal Instrumentation in spinal surgery ”, Clin Orthop;vol.227 E. Lou, V.J.Raso, B Martin,E.Epper and D.L.Hill,” A wireless load measurement tool for spine surgery,” D. Benfield, E.Lou, W Moussa. ”Development of a MEMS based sensor array to characterize in situ loads during scoliosis correction surgery”