Biometric sensor

Abstract

A bio metric sensor device (1) comprises: - a thin, flexible, layered sensor body (2); - a conductive sense plate (21); - a first non-conductive layer (41) between the sense plate and an outer surface(7); - a conductive shield plate (53) having a passage opening (54), overlaying the sense plate; - a second non-conductive layer (51) between the sense plate and the shield plate; - conductive circuit lines (73) on an inner surface (6); - a non-conductive separation layer (61, 71) between the shield plate and the circuit lines; - a signal processing circuit (100) mounted on the inner surface (6),the circuit (100) comprising a differential amplifier (110) having an input (111); - a conductive interconnector (82) crossing the second non-conductive layer (51) and the separation layer (61, 71),extending through the passage opening (54) of the shield plate (53), coupling the sense plate (21) and said input (111) of said amplifier (110).

Description

technical field [0001] The present invention generally relates to biometric sensors for sensing bioelectrical signals. Background technique [0002] It is well known that electrical signals are generated throughout the human body, and these signals represent electrical activity in the body. Important sources of this electrical activity are the heart, brain, moving muscles, etc. It is known to measure these electrical signals and to provide a temporal registration of these signals, eg electrocardiogram (ECG), electroencephalogram (EEG), electromyography (EMG), in order to obtain information about certain physical conditions. [0003] When measuring these signals, several problems must be overcome. The first problem has to do with the fact that human skin is a poor conductor. In this regard, measurement sensors can be classified as follows. Piercing sensors, such as needles, that pierce the skin and make good electrical contact with conductive parts of the body beneath the...

AI Technical Summary

Problems solved by technology

[0005] The second issue concerns user comfort

Rigid sensors are undesirable in this application as they are uncomfortable for the user

Furthermore, stiff sensors have the problem of only poor contact with the skin: to achieve good contact, biometric sensors need to be flexible enough to adapt to and change with the bending of the body, such as in muscles. when exercising

The downside of this design is that it needs to be adapted to the textile manufacturing process

Another disadvantage is that the fabric typically covers a large surface area, resulting in a low spatial resolution for the sensor

Conversely, if a cloth with a smaller surface area were to be used, the sensor would contain only a small number of conductive threads, resulting in poor coupling to the signal to be detected

[0008] On the other hand, such a sensor will be quite sensitive to signals from the surroundings, and it will be difficult to distinguish between actual human body signals and noise signals

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