Wireless charging of sensor device for diagnosis and monitoring

Inventors

Mohanty, Pritiraj • Erramilli, Shyamsunder

Assignees

FemtoDx Inc

Abstract

This application describes a novel approach of wireless charging or powering of a sensor-based device used for in vivo diagnosis and monitoring. In addition to implantable or subcutaneous devices, this approach can also be used for wireless charging of wearable and handheld devices. Specifically, this application describes charging of diagnostic and monitoring devices used for disease detection and management. More specifically, this application describes a method to wirelessly power integrated devices designed to detect or monitor analytes (e.g. biological or chemical species) and release drugs into the body in response to a specific change in the body's vitals, detected by the device.

Core Innovation

An implantable device is provided that uses a wireless patch antenna including a planar microstrip radiator and a parallel ground plane separated by a dielectric to transmit and receive electromagnetic radiation. A resonator is configured to receive electromagnetic radiation from the wireless patch antenna and comprises a single crystal silicon layer, an electrode layer, and an aluminum nitride layer positioned between the single crystal silicon layer and the electrode layer.

The implantable device further includes a rectifier in electrical communication with the resonator. The rectifier includes a set of diodes and converts the electromagnetic radiation to DC power. The disclosed system is presented as an ultracompact biocompatible wireless powering system for implantable/subcutaneous or wearable diagnostic/monitoring devices.

The document addresses wireless powering for implantable or wearable diagnostic/monitoring devices in a manner that is ultracompact and biocompatible, while enabling safe electromagnetic exposure within SAR limits and exposure limits. The disclosed approach supports RF wireless power transfer in a 2–6 GHz frequency band and is described as applicable to brain optogenetics.

The document also describes biocompatible hermetic packaging and tuning/matching elements associated with RF power transfer, together with modeling and testing involving SAR and heating in multi-layer head tissue phantoms and distance-dependent receiver characterization.

Claims Coverage

The independent claim identified (clm-00001) covers three core inventive elements: a wireless patch antenna, a resonator with a specified multilayer material stack, and a diode-based rectifier converting received electromagnetic radiation to DC power. Dependent claims refine resonator and antenna matching, electrical lengthening, filter stages, and a size constraint for the resonator implementation.

Overall, the claim set centers on converting electromagnetic radiation received from a microstrip patch antenna into DC power using a diode rectifier, where the resonator is defined by a specific material stack and is further refined via frequency and impedance matching, electrical lengthening, optional pre- and post-rectifier filters, and a micromechanical size constraint.

Stated Advantages

Documented Applications