NFC for Pervasive Healthcare Monitoring

We undertake a step-by-step approach in the design of two Near Field Communication (NFC) products for pervasive healthcare monitoring. Our first product is an NFC based battery charger circuit to charge a thermometer equipped with wireless communication. Our system design has a simple linear charger, with overvoltage and under voltage protection implemented as an android App. The NFC power source provides 13 -- 15 mW of continuous power and is able to charge a 45mAH battery in about 10 hours from deep discharge to full charge state. Since the weight of the charger is about 3 grams and the size is about 2 cms in diameter, this product is useful for wearable sensor devices and provides a convenient way of recharging the batteries without the need for any connectors in the device. This allows devices to be hermetically sealed, besides enabling smaller form factors. The second product is an NFC based battery-less medical grade thermometer. To obtain the temperature of a single patient, a maximum of 10 seconds is sufficient to read the sensor value starting from placement of a smartphone over the product.