Recent interest in human activity monitoring has spurred a great deal of research into the implantable sensor devices. The integration of an ultra-low power wireless transmitter has become a crucial factor in the design of implantable devices. We have developed a new design method of an extremely low-power transmitter using inductive coupling. Our approach makes it possible to integrate wireless components into a single silicon chip. It also provides a low cost and small-size implementation of next-generation medical instruments such as capsule endoscopes.
Developed CMOS one-chip wireless camera with digital image transmission function. | The chip specifications and the measured performance summary. |
Miniaturized wireless camera module. | Captured image. |
A prototype image sensor chip which has 320x240 effective pixels was fabricated using 0.25um CMOS image sensor process. With a 2.0 V power supply, the analog part consumes 950uW and the total power consumption is about 2.6mW. This extremely low power consumption is useful for long life battery operation. Error-free image transmission over a distance of 48cm at the data rate of 2.5Mbps corresponding to 2 fps has been demonstrated.