Method for Minimizing Coaxial Cable Effects on Measurements in Electrical Impedance Tomography

Background:

In electrical impedance tomography, multiple current sources are connected via cables to electrodes on the body surface. These current sources apply precise current patterns to the body. Applied currents (and measurements of the voltages that the currents produce on the electrodes) are used by reconstruction algorithms to produce images of the body’s interior. Cable impedance can reduce current, therefore currents applied to the electrode differ from those applied to the cable by the sources. There can also be a voltage difference between the two ends of each cable, so voltages measured at the current source differ from those at the electrode side. Conventional cable compensation techniques (e.g. those used in impedance measurement instruments) enable accurate impedance measurement at the cable end, but do not ensure the application of desired current.

Technology Overview:

This technology compensates for the effects of a cable connecting a source to a load during electrical impedance tomography measurements. When driven by a current source, the technology delivers the desired current to the load, and determines the voltage on the load from measurements made at the current source end of the cable. It uses the measured ABCD parameters for the cables and an adaptive algorithm to control the current sources to produce the desired currents at the electrodes, and accurately measures the electrode voltages at the current source ends of the cables. This ensures the desired current is applied.

Advantages:

•    Compensates for the effects of a cable connecting a source to a load during electrical impedance tomography measurements. 
•    Ensures the desired current is applied.

Applications:

The primary application for this technology is compensating for cable effects in electrical impedance tomography.

Intellectual Property Summary:

 Patent application filed
US PATENT APPLICATION NUMBER - 18/920,713

Stage of Development:

TRL 3 – Experimental proof of concept

Licensing Status:

This technology is available for licensing.

Licensing Potential:

This technology would be of interest to entities involved in compensating for cable effects in electrical impedance tomography. These include:
•    Electrical engineers.
•    Research laboratories.
•    Impedance instruments manufacturers.