A 3D localization system using magnetic field gradients that can replace X-Ray fluoroscopy in high precision surgery has been developed by our team. Monotonically varying magnetic fields encode spatial points uniquely in the field-of-view and are sensed by miniaturized devices with wireless power and data telemetry. Relative device locations are displayed in real-time. A prototype system consisting of a 65nm CMOS chip and gradient coils achieves a localization error of <100µm in 3D when tested in-vitro.
We present an alternative approach to microscale device localization based on concepts from nuclear magnetic resonance. In particular, the magnetic-field-dependent precession frequency of nuclear spins allows their location in space to be encoded through the application of magnetic field gradients. This allows MRI to visualize signals from nuclear spins located throughout a specimen with ~100 µm resolution.
Miniaturization of implantable biosensors for continuous, in vivo monitoring of clinically relevant analytes is an important step toward viability of such devices. While wireless power delivery via on-chip antennas promises miniaturization and realization of minimally invasive devices, it can only support low levels of power consumption. This is due to the significant tissue absorption at high frequencies, small size of the chip and quality factor of on-chip inductors. Therefore, reducing the power consumption of the sensor while maintaining high sensitivity and dynamic range is crucial.
Most progressive vision loss occurs when the first layer of the retina (the photoreceptors) is damaged. Retinal prostheses aim to restore vision by bypassing the damaged photoreceptors and directly stimulating the remaining healthy neurons. Our approach uses highly scaled technologies to reduce area and power, and to support hundreds of channels for fully intraocular implants.
Origami implant design is a 3D integration technique which addresses the size and cost constraints in biomedical implants. Large systems can be split into multiple chips and connected using 3D integration techniques to be folded compactly for implantation and unfolded inside the body. Electronics can be partitioned into functional blocks for mass-production and customs implants can be assembled from these relatively cheap modules.