NON-INVASIVE DEEP MUSCLE ELECTROMYOGRAPHY

• US 20120184838A1
• Filed: 07/29/2010
• Published: 07/19/2012
• Est. Priority Date: 07/30/2009
• Status: Active Grant

• Current Assignee: South African Medical Research Council, University Of Cape Town
• Original Assignee: South African Medical Research Council, University Of Cape Town
• Inventors: John, Lester Ryan
• Granted Patent: US 9,687,168 B2
• Time in Patent Office: Days
• US Class Current: 600/390
• CPC Class Codes: A61B 2562/043 in a linear array
• CPC Class Codes: A61B 5/0536 Impedance imaging, e.g. by tomography
• CPC Class Codes: A61B 5/1107 Measuring contraction of parts of the body, e.g. organ, muscle apparatus for measuring work or force in general G01L
• CPC Class Codes: A61B 5/296 for electromyography [EMG]
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/389 Electromyography [EMG]
• CPC Class Codes: A61B 5/4519 Muscles A61B5/389, A61B5/224 take precedence
• CPC Class Codes: A61B 5/6802 Sensor mounted on worn items
• CPC Class Codes: A61B 5/6824 Arm or wrist
• CPC Class Codes: A61B 5/6831 Straps, bands or harnesses
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: G06F 2218/22 Source localisation; Inverse modelling

Abstract

A method and apparatus for conducting electromyography of a deep muscle non-invasively are provided. An array of suitable surface electromyography electrodes is arranged in one or more rings encircling a part of the human body in which a deep muscle being investigated is located. The potential of at least selected electrodes relative to another electrode selected from a common reference electrode (mono-polar) and other electrodes (bi-polar) in the array is recorded and the data is processed in respect of the recorded potentials of at least some of said selected electrodes in order to determine (optionally using approximations or algorithms, or both) the contribution being made by at least the deep muscle being investigated. Typically, this is done mathematically by resolving the electromyography signals into their constituent components using a suitable technique. Preferably, this is integrated with a static muscle imaging device that may use the same electrodes to obtain a static tomogram of the muscles encircled.

Claims

1. A method of conducting electromyography of a deep muscle non-invasively comprising the application of an array of suitable surface electromyography electrodes to the skin of a patient and recording electrical potentials of selected electrodes relative to at least one other electrode, the method being characterised in that the array of electrodes is arranged in one or more rings encircling a part of the human body in which a deep muscle being investigated is located, recording the potential of at least selected electrodes relative to another electrode selected from a common reference electrode (mono-polar) and other electrodes (bi-polar) in the array;

and processing the recorded potentials of at least some of said selected electrodes in order to determine (optionally using approximations or algorithms, or both) the contribution being made by at least said deep muscle being investigated.

2. A method as claimed in claim 1 in which the contributions to the potentials of the electrodes attributable to each of the encircled muscles (a, b, c, d, e) including superficial muscles (a, b, d, e) is determined, typically mathematically by resolving the electromyography signals into their constituent components using a technique selected from independent component analysis (ICA) and any other suitable un-mixing or matrix inversion technique to result in the derivation of the electromyography waveforms of both deep and superficial muscles.

3. A method as claimed in claim 1 in which the deep muscles are identified by selecting specific movement protocols.

4. A method as claimed in claim 3 in which the movement protocols are similar to those used to identify muscles by conventional (sEMG or needle/fine-wire) techniques.

5. A method as claimed in claim 1 in which the results of the method are integrated with those of a static muscle imaging device that may use the same electrodes to obtain a static tomogram of the muscles encircled.

6. A method as claimed in claim 5 in which the static tomogram is co-registered with the dipole decomposition or any other suitable 2D or 3D electrical source localisation technique of the ICA-sEMG waveforms.

7. A method as claimed in claim 5 in which the static muscle imaging device is selected from an electrical impedance tomography device, an ultrasound device, a computed tomography device (CT), and a magnetic resonance imaging device (MRI).

8. Apparatus for carrying out a method as claimed in claim 1 comprising multiple surface electromyography electrodes having flexible conductors connecting them individually to recording means and computing means adapted to carry out an independent component analysis, or any other suitable un-mixing or matrix inversion technique, on the potentials of the electrodes recorded in order to provide the electromyography waveform of at least one deep muscle encircled by one or more rings of multiple electrodes secured to the skin of the human body, in use.