Remotely Powered Two-Wire Cooperative Sensors for Bioimpedance Imaging Wearables.

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Electrical Engineering

Background:

• Conventional electrical impedance tomography (EIT) systems use bulky cabling unsuitable for wearable applications.
• Cooperative sensors with a two-wire bus reduce cabling complexity for bioimpedance measurements.
• Previous work enabled battery-free cooperative sensors for biopotential measurements.

Purpose of the Study:

• To adapt battery-free cooperative sensor technology for bioimpedance measurements.
• To develop a compact and wearable EIT system for generating 3D resistivity and permittivity maps of biological tissue.
• To evaluate discrete component and ASIC approaches for powering wearable EIT sensors.

Main Methods:

• Utilized a two-wire parallel bus for sensor communication and power delivery.
• Investigated two methods for implementing battery-free cooperative sensors: discrete components and an application-specific integrated circuit (ASIC).
• Applied the system to measure bioimpedances for creating functional 2D and 3D tissue maps.

Main Results:

• Demonstrated the feasibility of powering cooperative sensors for bioimpedance measurements using a central unit over a two-wire bus.
• Both discrete component and ASIC approaches proved successful.
• The ASIC approach showed superior medical safety, reduced power consumption, and smaller device size.

Conclusions:

• A battery-free wearable EIT system is achievable using cooperative sensors powered over a two-wire bus.
• The ASIC implementation offers significant advantages for wearable bioimpedance imaging systems.
• This technology advances the development of compact, safe, and efficient medical imaging devices.