Implantable Enzyme Sensor Tag System Architecture And Chip Design

Chronic disease such as hyperglycemia and diabetes mellitus ail the doctors and patients in the world. Traditional treatment of measuring cannot get real time information of a patient's blood sugar which is essential for preventing and controlling. Thus an enzyme sensor system which can achieve real time regulation, bedevil patients less, and facilitate measurement is necessary for interdisciplinary science. Wireless implantable enzyme sensor has the proposed advantage and is becoming a hot point in designing Blood Glucose Monitor. A wireless implantable glucose sensor must solve the problem that wireless signal attenuates sharply in body and can measure weak current signal in order to minimize the senor's size to mitigate the hurt to body. Also encryption is needed to protect privacy of the patient during communication.This paper proposes a combination of enzyme sensor and HF RFID tag as a wireless implantable enzyme sensor. Since the tag sensor is passive and all the power comes from the RFID reader, the paper analyses the coefficient of coupling between the transmuting and receive coil when changing their relative location and embedded depth in skin and then deduce the power transmission efficiency of the system. The analysis provides theoretical basis and optimization method for implantable sensor. The paper also proposes circuit architecture with data encryption for data transmission from sensor to tag baseband. A work flow contains reset and self-calibration is schemed. The enzyme sensor chip is designed to measure current with the range of l0fA-100pA and its transmission channel is accordance with ISO 15693 protocol. Hummingbird algorithm is used to encrypt the communication channel. After circuit simulation the chip is taped out in the process of SMIC 0.13μm EEPROM and SMIC 0.13μm RF technology.