Shielding techniques for noise reduction in surface electromyography signal measurement and related systems and methods

• US 10,687,759 B2
• Filed: 05/28/2019
• Issued: 06/23/2020
• Est. Priority Date: 05/29/2018
• Status: Active Grant

• Current Assignee: META Platforms Technologies LLC (Meta Platforms, Inc. (f/k/a Facebook, Inc.))
• Original Assignee: Facebook Technologies, LLC (Meta Platforms, Inc. (f/k/a Facebook, Inc.))
• Inventors: Guo, Ning, Barachant, Alexandre, Reid, Jonathan
• Primary Examiner(s): Ngo, Hung V
• Application Number:
  US16/424,144
• Publication Number:
  US 20190365318A1
• Time in Patent Office: 392 Days
• CPC Class Codes: A61B 2562/043 in a linear array
• CPC Class Codes: A61B 2562/182 Electrical shielding, e.g. using a Faraday cage
• CPC Class Codes: A61B 5/296 for electromyography [EMG]
• CPC Class Codes: A61B 5/313 for electromyography [EMG]
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• CPC Class Codes: A61B 5/6824 Arm or wrist
• CPC Class Codes: H03F 1/26 Modifications of amplifiers to reduce influence of noise generated by amplifying elements
• CPC Class Codes: H03F 2200/261 Amplifier which being suitable for instrumentation applications
• CPC Class Codes: H03F 2203/45544 the IC comprising one or more capacitors, e.g. coupling capacitors
• CPC Class Codes: H03F 2203/45548 the IC comprising one or more capacitors as shunts to earth or as short circuit between inputs
• CPC Class Codes: H03F 2203/45604 the IC comprising a input shunting resistor
• CPC Class Codes: H03F 3/45475 using IC blocks as the active amplifying circuit
• CPC Class Codes: H05K 9/0007 Casings standardised racks H05K9/0062

Abstract

Techniques for shielding wearable surface electromyography (sEMG) devices are described. According to some aspects, an sEMG device may comprise amplification circuitry comprising at least a first differential amplifier and at least two sEMG electrodes electrically connected to the amplification circuitry. The device may further comprise at least one auxiliary conductor not electrically connected to the amplification circuitry, wherein the at least one auxiliary conductor is configured to be electrically coupled to a wearer of the wearable device, and an electromagnetic shield surrounding the wearable device at least in part and electrically connected to the at least one auxiliary conductor.

Claims

1. A wearable device comprising:

amplification circuitry comprising at least a first differential amplifier;

at least two dry sEMG electrodes electrically connected to the amplification circuitry;

at least one auxiliary conductor not electrically connected to the amplification circuitry, wherein the at least one auxiliary conductor is configured to be electrically coupled to a wearer of the wearable device; and

an electromagnetic shield electrically connected to the at least one auxiliary conductor,

wherein the amplification circuitry is positioned between the electromagnetic shield and the at least two dry sEMG electrodes.

2. The wearable device of claim 1, wherein the electromagnetic shield surrounds at least one input of the first differential amplifier.

3. The wearable device of claim 1, wherein the electromagnetic shield comprises a metal.

4. The wearable device of claim 1, wherein the electromagnetic shield comprises a conductive fabric.

5. The wearable device of claim 1, wherein the electromagnetic shield comprises a conductive paint applied to the at least a portion of the wearable device.

6. The wearable device of claim 1, wherein the electromagnetic shield comprises a conductive tape.

7. The wearable device of claim 1, wherein the electromagnetic shield comprises a conductive plastic.

8. The wearable device of claim 1, wherein the first differential amplifier comprises a field-effect transistor (FET).

9. The wearable device of claim 1, wherein the first differential amplifier is configured to have an input impedance of at least 1 GΩ

.

10. The wearable device of claim 1, wherein the at least one auxiliary conductor includes one or more sEMG electrodes.

11. The wearable device of claim 1, wherein the at least one auxiliary conductor includes a conductive cylinder, ring and/or torus.

12. The wearable device of claim 1, further comprising a housing, and wherein the electromagnetic shield is arranged within the housing.

13. The wearable device of claim 1, further comprising a housing, and wherein the electromagnetic shield comprises a conductive paint applied to the housing.

14. The wearable device of claim 1, wherein one or more of the at least two dry sEMG electrodes are configured to pass through at least some portion of the wearer'"'"'s dermis.