Stretchable electrode and method of making physiologic measurements

Abstract

A stretchable electrode for use in physiologic measurements on a human body, such as peripheral impedance plethysmography, is disclosed. One embodiment of the stretchable electrode comprises an uninsulated stainless steel wire braid formed into a tubular conductor surrounding an elastic core and attached to an elastic substrate or base. Other embodiments of the stretchable electrode include a garter spring, a flat braided or woven conductor and an undulating wire. The electrode may be placed about a limb of a human body and elastically stretched so that the conductor is in substantially continuous circumferential electrical contact with the skin of the limb. A method of attaching the stretchable electrode to the limb of a human body is also disclosed.

Description

REFERENCE TO RELATED APPLICATIONS[0001]The following commonly assigned patent applications disclose and claim subject matter related to the subject matter of the present invention: U.S. patent application Ser. No. 10 / 392,308, filed Mar. 20, 2003, entitled “Peripheral Impedance Plethysmography Electrode and System with Detection of Electrode Spacing;” U.S. patent application Ser. No. 10 / 673,167, filed Sep. 30, 2003, entitled “Methods of Diagnosis Using Pulse Volume Measurement;” U.S. patent application Ser. No. 10 / 673,328, filed Sep. 30, 2003, entitled “Signal Averaging Using Gating Signal Obtained from Autocorrelation of Gating Signals;” and U.S. patent application Ser. No. 10 / 759,130, filed Jan. 20, 2004, entitled “Method and Device for Measuring Peripheral Vascular Function.” The disclosures of those applications are hereby incorporated by reference in their entireties into the present application.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present inventio...

AI Technical Summary

Benefits of technology

The stretchable electrode ensures uniform and continuous electrical contact along the body's circumference, reducing measurement inaccuracies and enabling cost-effective, reusable solutions for physiologic measurements like impedance plethysmography.

Problems solved by technology

This will result in inaccurate measurements.

Disposing of multiple quadripolar electrodes for these tests would be prohibitively expensive.

With respect to a quadripolar electrode system, from a practical standpoint, it is not desirable for the user to have to place four separate electrodes on each limb to create the quadripolar arrangement but, rather, to place each current-voltage pair together in a single array.

Because the braided electrode is stretched out before it is applied to the skin of the neck and thorax, it has no restoring force that aids in maintaining reliable low impedance contact with the skin, i.e., it is not elastic.

The conductive loop is not, however, elastic or stretchable along the axial length of the conductor, nor does it make electrical contact with the skin of the subject.

The foregoing and other prior art electrodes used in physiologic measurements have not provided a reusable electrode that is characterized by a reliable low impedance electrical contact with the skin.

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