Impedance and temperature measurement for bio-medical application
In this research for the temperature sensor, a new way of flexible, wearable trans-thoracic electrical impedance measurement systems to prevent heart failure is being studied. The whole system can be attached to the skin using medical tape and does not need tight clothing or uncomfortable straps. In another application the impedance sensor is used for cell characterization. To the best of our knowledge, our topology is the first using current change for measuring resistance and delay to measure capacitance, implementing both impedance particles.
with only 4 circuit blocks. The output of our system is frequency, which can be transmitted without the need for bulky and power-consuming analog to digital converter blocks. Using a custom impedance measurement circuit makes this system have the lowest weight and power consumption among the state of art designs. In other sensor research A Sub-uw CMOS temperature to frequency sensor for implantable devices is designed. Sensors used in implantable devices must have sub-uW power consumption to avoid tissue overheating. Thus this temperature sensor employs subthreshold MOS as the sensing element to reduce power consumption and enable minimum supply voltage. The frequency conversion topology is chosen in these sensors and applications based on its low power consumption.
Hardware Security
Since biomedical sensors are getting integrated with the Internet of Things (IoT) systems, IoT security, previously ignored, has now become critical to address. The hardware integrated security implementation, code the signal from the start, eliminating the source of threat to your privacy. I develop a new use of chaotic circuits as a method of ciphering communication in IoT devices. The system is then fabricated in CMOS technology as a single chip. Chaotic systems, each with different starting initial conditions, because of the exponential divergence of the nearby trajectories of chaotic systems, may seem surprising to match. However, when the two systems are coupled. They share a single state, which is provided by the drive system, and can exhibit a phenomenon known as Synchronization of Chaos.
Parkinson Monitoring
Parkinson’s disease (PD) is a progressive neurodegenerative disorder of the central nervous system with a predilection for dopamine systems early in the disease. The progressive neuronal degeneration is a combination of the environmental factors and genetic predisposition. About 3% of the population over the age of 65 years suffer from Parkinson’s disease. In this research I lead a team in developing a cheap, portable constant monitoring system. This system detect patient fall for emergency notification and performs daily tests for disease progression monitoring.
Paper Electrode
Electrochemical sensing is a widely used tool to quantify analytes such as glucose and dopamine which are important indicators. A real-time electrochemical monitoring system should be small in size, operate on a limited power budget, and show a linear relationship over the required measurement range. In this research I developed a pencil drawn paper electrode for glucose detection. The discrete low cost (<$2) potentiostat is implemented with a discrete control amplifier and two versions of the current to voltage unit. The transimpedance amplifier (TIA) is implemented as discrete module and is compared to a common gate based TIA.
Ava Hedayatipour 