Wearable System for Detecting and Measuring Biosignals

• US 20170027517A9
• Filed: 07/30/2014
• Published: 02/02/2017
• Est. Priority Date: 07/30/2013
• Status: Active Grant

• Current Assignee: EMOTIV Inc.
• Original Assignee: Emotiv Lifesciences, Inc.
• Inventors: Le, Tan, Mackellar, Geoffrey
• Granted Patent: US 10,194,865 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 5/02055 Simultaneously evaluating both cardiovascular condition and temperature
• CPC Class Codes: A61B 5/02405 Determining heart rate variability
• CPC Class Codes: A61B 5/0245 by using sensing means generating electric signals, i.e. ECG signals
• CPC Class Codes: A61B 5/0533 Measuring galvanic skin response
• CPC Class Codes: A61B 5/1112 Global tracking of patients, e.g. by using GPS
• CPC Class Codes: A61B 5/1126 using a particular sensing technique
• CPC Class Codes: A61B 5/245 specially adapted for magnetoencephalographic [MEG] signals
• CPC Class Codes: A61B 5/282 Holders for multiple electrodes for introduction into the body A61B5/287
• CPC Class Codes: A61B 5/291 for electroencephalography [EEG]
• 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 5/398 Electrooculography [EOG], e.g. detecting nystagmus; Electroretinography [ERG]
• CPC Class Codes: A61B 5/6803 Head-worn items, e.g. helmets, masks, headphones or goggles
• CPC Class Codes: A61B 5/6814 Head
• CPC Class Codes: A61B 5/6835 Supports or holders, e.g., articulated arms
• CPC Class Codes: A61B 5/7217 of noise originating from a therapeutic or surgical apparatus, e.g. from a pacemaker

Abstract

A system for detecting bioelectrical signals of a user comprising: a set of sensors configured to detect bioelectrical signals from the user, each sensor in the set of sensors configured to provide non-polarizable contact at the body of the user; an electronics subsystem comprising a power module configured to distribute power to the system and a signal processing module configured to receive signals from the set of sensors; a set of sensor interfaces coupling the set of sensors to the electronics subsystem and configured to facilitate noise isolation within the system; and a housing coupled to the electronics subsystem, wherein the housing facilitates coupling of the system to a head region of the user.

Claims

8. A system for detecting bioelectrical signals of a user and reducing noise, comprising:

a set of sensors configured to detect bioelectrical signals from the user, each sensor in the set of sensors positioned proximal to a region of the scalp of the user upon coupling of the system to the user, wherein the set of sensors includes a common mode sensor configured to detect an ambient signal through the scalp of the user;

an electronics subsystem comprising a digital electronics subsystem and an analog electronics subsystem separated from and coupled to the digital electronics subsystem by an inter-board connection, the analog electronics subsystem comprising a hum remover that reduces noise based upon the ambient signal of the common mode sensor;

a set of sensor interfaces configured to couple the set of sensors to the electronics subsystem and to amplify and shift bioelectrical signal voltages transmitted to the electronics subsystem; and

a housing surrounding the set of sensors and the electronics subsystem, comprising a set of arms configured to position each sensor in the set of sensors proximal to the region of the scalp of the user upon coupling of the system to the user.

9. The system of claim 8, wherein noise-producing electronics elements are isolated to one of the digital electronics subsystem and the analog electronics subsystem.

12. The system of claim 9, wherein the analog electronics subsystem further comprises a multiplexer, an amplifier coupled to an output of the multiplexer, an ADC coupled to the multiplexer through the amplifier, and a mid-rail generator producing a midrail voltage line of the electronics subsystem.

13. The system of claim 12, wherein the multiplexer is characterized by a 2̂

n relationship between a number of input lines into the multiplexer and a number of select lines of the multiplexer.

14. The system of claim 12, wherein the hum remover of the analog electronics subsystem is configured to sample the ambient signal of the common mode sensor, to integrate the ambient signal with a square wave signal to produce a driven right leg signal, and to feed the driven right leg signal to the user by way of the set of sensors, wherein a frequency of the square wave signal is higher than a frequency range corresponding to bioelectrical signals of the user.

15. The system of claim 14, wherein the hum remover is further configured to center the driven right leg signal about the midrail voltage line produced by the midrail generator.

16. The system of claim 12, wherein the inter-board connection comprises a pin-strip coupling that allows power transmission and limits signal transmission between the digital electronics subsystem and the analog electronics subsystem.

17. The system of claim 12, wherein each sensor interface in the set of sensor interfaces comprises a pre-gain AC coupling and level shift coupled to an amplifier, wherein the amplifier is coupled to a post-gain coupling and level shift, configured to center an output of the post-gain coupling about the midrail voltage line produced by the midrail generator.

18. The system of claim 8, wherein the set of sensors comprises a first anterior frontal sensor configured to detect EEG signals from a first frontal lobe region, a second anterior frontal sensor configured to detect EEG signals from a second frontal lobe region, a first temporal lobe sensor configured to detect EEG signals from a first temporal lobe region, a second temporal lobe sensor configured to detect EEG signals from a second temporal lobe region, and a central sensor configured to detect EEG signals from a parietal lobe region upon coupling of the system to the user.

19. The system of claim 8 wherein each sensor of the set of sensors includes a sensor pad composed of a polyhydroxyethylmethacrylate hydrogel saturated with non-volatile electrolyte configured to provide non-polarizable contact upon coupling of the system to the user.

20. The system of claim 19, wherein the analog electronics subsystem is configured to support input impedances from 1 MΩ

to 1 GΩ

, characteristic of an interface between the sensor pad and skin of the user upon coupling of the system to the user, by way of the set of sensor interfaces coupled to the set of sensors.

10-1. system of claim 10, wherein the digital electronics subsystem is further configured to couple to a motion sensing module comprising a gyroscope, an accelerometer, and a magnetometer, thereby enabling absolute position and motion sensing at the motion sensing module.