Smitha M. N. Rao

Learn More
This paper presents design and optimization methods for spiral coils utilized for wireless power transfer in wireless medical implant applications. A theoretical model was examined for near-field distributions of spiral-type transmitter antennas in both orthogonal components. Finite-element simulations were performed to verify the theoretical radiation(More)
In this study, a device for gastroesophageal reflux disease (GERD) monitoring has been prototyped. The system consists of an implantable, batteryless and wireless transponder with integrated impedance and pH sensors; and a wearable, external reader that wirelessly powers up the transponder and interprets the transponded radio-frequency signals. The(More)
Stomach contractions are initiated and coordinated by an underlying electrical activity (slow waves), and electrical dysrhythmias accompany motility diseases. Electrical recordings taken directly from the stomach provide the most valuable data, but face technical constraints. Serosal or mucosal electrodes have cables that traverse the abdominal wall, or a(More)
— This study investigated wireless power transfer with inductive coupling at a distance addressing the power requirement for chronic gastrostimulator implants. The energy harvesting system was designed to collect 3 to 20 mW power to operate an implantable stimulator to deliver 1 to 6 mA electric current into stomach tissues. The power transfer system(More)
— Implantable devices are currently used regularly for chronic pain relief, cardiac pacemakers, arterial infusion for cancer and insulin delivery. A MEMS based implantable drug delivery system (IDDS) integrating a subcutaneous reservoir, an in plane silicon pump and associated circuitry for local or centralized delivery of therapeutic agents for(More)
In this paper, we report a power management system for autonomous and real-time monitoring of the neurotransmitter L-glutamate (L-Glu). A low-power, low-noise, and high-gain recording module was designed to acquire signal from an implantable flexible L-Glu sensor fabricated by micro-electro-mechanical system (MEMS)-based processes. The wearable recording(More)
— In this work, we developed a dual-sensor system to monitor the symptoms in gastroesophageal reflux disease (GERD). The system consists of an implantable transponder and an external reader. The passive telemetry for signal transduction is based on an inductive link between two coil antennas. The reader supplies radio frequency power, obtains and stores the(More)
BACKGROUND Chronic GERD affects approximately 15% of adults in the United States and is one of the most prevalent clinical conditions involving the GI tract. The commercial tools for monitoring GERD include multichannel intraluminal impedance (MII) probes and pH-sensing capsules. However, MII probes cause discomfort, which alters patients' regular(More)
We report a novel approach to study cell migration under physical stresses by utilizing established growth factor chemotaxis. This was achieved by studying cell migration in response to epidermal growth factor (EGF) chemoattraction in a gradually tapered space, imposing mechanical stresses. The device consisted of two 5-mm-diameter chambers connected by ten(More)
Flexible iridium oxide (IrOx)-based micro-electrodes were fabricated on flexible polyimide substrates using a sol-gel deposition process for utilization as integrated pseudo-reference electrodes for bio-electrochemical sensing applications. The fabrication method yields reliable miniature on-probe IrOx electrodes with long lifetime, high stability and(More)