© 2007 Maysam Ghovanloo
Text Box: Establishment of a telemetry link from inside to outside of the human body is needed in many biomedical implants especially when internal biosignals such as neural or muscular electrical activities, or parameters such as pressure, temperature, flow, or concentration of different ions or proteins need to be monitored. To improve implant safety, it should be able to run self-test routines, and report any malfunctioning blocks to the external part of the system. In addition, a closed-loop power regulation mechanism is needed to improve coupling insensitivity, and compensate for variations in the coils relative distance due to patient movements and coils misalignments. We are trying to implement a wideband and robust wireless link, using the Industrial-Medical-Scientific (ISM) band, as part of a neural recording system. More…. Sponsor: NC State College of Engineering, Startup funds Status: On going Text Box: Multichannel Wireless Neural Recording System Text Box: Deep brain stimulation (DBS) is one of the recent treatments that are found to be effective for Parkinson’s disease, essential tremor, dystonia, epilepsy, depression, and obsessive compulsive disorder. Today’s DBS devices, which have stemmed from the pacemaker technology, are mostly implanted in the chest area with wires running under the skin to the cranial electrodes. These wires are found to be the major cause of failure in DBS systems. Design of a small-size low-power head-mounted DBS system is the goal of this project. More…. Sponsor: NC State Research and Graduate Studies Interdisciplinary Faculty Research and Professional Development (FRPD) Status: On going Co-Investigators: Drs. Oleg Favorov and Richard Murrow Text Box: Low-Power Head-Mounted Deep Brain Stimulator Text Box: Assistive technologies are critical for people with disabilities in leading a self-sufficient independent life. Persons rendered quadriplegic as a result of causes ranging from traumatic brain injury to stroke generally find it extremely difficult to carry out everyday tasks. Assistive systems that would help them communicate their intentions effectively would greatly benefit this group of severely disabled individuals. The goal of this project is to help people with disabilities operate computers, radios, TVs, doors, motorized wheelchairs, hospital beds, and many other devices. More…. Sponsor: Christopher and Dana Reeve Foundation, National Science Foundation Status: On going Text Box: Assistive Environment Control Device for Quadriplegics Text Box: In classic analog circuit design, minimizing the number of transistors and keeping all of them in the saturation region are the main design criteria. By technology advancement towards processes with smaller feature size in deep submicron range, the circuit real estate occupied by transistors becomes less significant, especially in analog circuits where the passive components often occupy most of the silicon area. On the other hand, low-power analog circuit blocks should be able to handle the effects of gate and substrate leakage, more sensitivity in transistor matching, and reduced supply levels. Therefore, more complex analog circuits with a larger number of transistors would be justified in order to achieve the desired performance in low-power, low-voltage circuit design scenarios. As a result, especial circuit design techniques need to be developed to handle these transistors from a system point of view. Sponsor: Status: Looking for funds Text Box: RESEARCH INTERESTS: implantable biomedical devices, neural interfacing, rehabilitation engineering, bio-inspired microsystems, and low-power analog/digital/mixed-mode circuits. Here you can find a list of current and previous projects: Text Box: Research Projects Text Box: Real-time interfaces between the external world and the human nervous system, known as neural prostheses, can be used to restore sensory and motor functions that are lost through injury or disease. Effective interfacing with the central nervous system for restoration of the sensory modalities such as vision requires application of electrical stimulation through high-density interconnects in well-controlled temporal-spatial patterns similar to the natural cognitive neural activity. Some of the major challenges are the implant size, microassembly, stimulation strategy for controlling a large number of sites, low power consumption, wideband wireless link, and safety. We are trying to address the above issues by advancing the state-of-the-art in each one of these directions. More…. Sponsor: National Institute of Neural Disorders and Stroke, NIH Status: Completed Text Box: Wireless Neural Microstimulating System Text Box: Closed loop electrical pacing of the gastrointestinal (GI) system is a new treatment for gastrointestinal motility disorders. The organs of the GI system, like the heart in the cardiac system, have natural pacemakers that regulate the contractions and hence the motility of the stomach through myoelectrical activity. Similar to the electrical pacemaking of the heart, this myoelectrical activity can be entrained by external electrical pacing using multi-site stimulators. Existing stimulators, however, are open-looped and at best can reduce the symptoms including nausea and vomiting. Studies have shown that a closed loop system will be capable of reducing the symptoms as well as regulating and even treating motility disorders. Another huge application of these closed loop gastric pacing systems is treatment of the morbid obesity by reducing the desire for food intake and its absorption through the GI tract, which is a significant growing concern in today’s modern societies especially here in the United States. Sponsor: Private sector Status: On going Text Box: Closed Loop Gastro-Intestinal Pacer Text Box: Patients forget to take their medicine, they may think side effects outweigh benefits, they may not believe the diagnosis, they may not understand the directions correctly, they may not know enough about the side-effects, they may use too much, or they may view the medicine as too costly. For whatever reason, even the best medications cannot make any difference if the patients do not take them in the right doses at the right time. The topic of “pharmaceutical compliance” has become a key issue due to increasing difficulties in achieving point-of-differentiation and health economic objectives justifying premium pricing and reimbursement. We are working on a novel drug compliance device suitable for clinical and pharmaceutical trials. It can also be an integrated part of the marketed drug concepts. Sponsor: Private sector Status: On going Text Box: The wireless link operating frequency, also known as the carrier frequency, is one of the most important parameters of an inductive link, which affects all other system specifications. Traditionally, a single carrier frequency has been used for (1) inductive power transmission, (2) forward data transmission from outside to the implanted device, and (3) back telemetry from the implanted device outward. In this research we are using three carrier signals at three different frequencies and amplitude levels: (a) low-frequency high-amplitude (fP < 1MHz) for power transmission, (b) medium-frequency medium-amplitude (fFD ~ 50MHz) for forward data link, and (c) high-frequency low-amplitude (fBT > 1GHz) for back telemetry. These frequencies are optimal for the above three major functions and we can effectively isolate many of the competing parameters in the design of a wireless link. Therefore, we expect to achieve a high performance in all of the aforementioned system requirements. More…. Sponsor: NC State Research and Graduate Studies Interdisciplinary Faculty Research and Professional Development (FRPD) Georgia Institute of Technology, Startup funds Status: On going Text Box: Multi-Carrier Wireless Link for Implantable Biomedical Devices