Biometric sensor arrangement and method for generating a biometric signal

• US 10,420,492 B2
• Filed: 07/27/2016
• Issued: 09/24/2019
• Est. Priority Date: 07/28/2015
• Status: Active Grant

• Current Assignee: ams AG (Ams-Osram AG)
• Original Assignee: ams AG (Ams-Osram AG)
• Inventors: Enenkel, Jan
• Primary Examiner(s): Winakur, Eric F
• Assistant Examiner(s): Mustansir, Abid A
• Application Number:
  US15/221,448
• Publication Number:
  US 20170027488A1
• Time in Patent Office: 1,154 Days
• CPC Class Codes: A61B 2010/0009 Testing for drug or alcohol abuse
• CPC Class Codes: A61B 2562/0233 Special features of optical sensors or probes classified in A61B5/00
• CPC Class Codes: A61B 2562/0238 Optical sensor arrangements for performing transmission measurements on body tissue
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/443 Evaluating skin constituents, e.g. elastin, melanin, water
• CPC Class Codes: A61B 5/4872 Body fat
• CPC Class Codes: A61B 5/4875 Hydration status, fluid retention of the body
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• CPC Class Codes: A61B 5/6898 Portable consumer electronic devices, e.g. music players, telephones, tablet computers

Abstract

A biometric sensor arrangement (10) comprises a first radiation source (11), a second radiation source (12) that is implemented as a flash radiation source and a driver (13) coupled to the first and the second radiation source (11, 12) and configured to selectively operate the first and the second radiation source (11, 12). Moreover, the biometric sensor arrangement (10) comprises a photosensor (16) and a signal conditioning unit (18) coupled to the photosensor (16) and designed to provide a biometric signal (SB).

Claims

1. A biometric sensor arrangement, comprising:

a first radiation source,

a second radiation source that is realized as flash light-emitting diode which is implemented as white light-emitting diode and is fabricated for conducting a high current that is higher than 500 mA,

a driver coupled to the first and the second radiation source and configured to selectively operate the first and the second radiation source,

a photosensor and

a signal conditioning unit operable to provide a biometric signal,

wherein the signal conditioning unit comprises a transimpedance amplifier and an analog-to-digital converter,

wherein the transimpedance amplifier comprises an operational amplifier and a feedback resistor that couples a first input of the operational amplifier to an output of the operational amplifier

wherein a terminal of the photosensor is connected to the first input of the operational amplifier,

wherein a second input of the operational amplifier is connected to a reference potential terminal,

wherein the first input of the operational amplifier is an inverting input, and the second input of the operational amplifier is a non-inverting input, and

wherein the analog-to-digital converter is coupled to the output of the operational amplifier.

2. The biometric sensor arrangement according to claim 1,

wherein the photosensor is configured to provide a photon signal as a function of radiation emitted by the first radiation source.

3. The biometric sensor arrangement according to claim 1,

wherein the driver is configured to operate the first radiation source in a first operating phase and to operate the second radiation source in a second operating phase.

4. The biometric sensor arrangement according to claim 3,

wherein the signal conditioning unit is configured to provide the biometric signal depending on a photon signal generated by the photosensor in the first operating phase and independent from the photon signal in the second operating phase.

5. The biometric sensor arrangement according to claim 3,

wherein the driver is configured such that the second radiation source emits a flash in the second operating phase.

6. The biometric sensor arrangement according to claim 1,

wherein the first radiation source is configured to emit radiation at a first wavelength and the second radiation source is configured to emit radiation at a second wavelength that is different from the first wavelength.

7. The biometric sensor arrangement according to claim 1,

wherein the first and the second radiation source are realized as light-emitting diodes and form an anti-parallel circuit of diodes.

8. The biometric sensor arrangement according to claim 7,

wherein the driver is implemented as a H-bridge that is configured to supply the first and the second radiation source.

9. The biometric sensor arrangement according to claim 7,

wherein the driver comprises a current source, a further current source and a converter, and

wherein the further current source couples a supply terminal to a first driver terminal, the current source couples an output of the converter to the first driver terminal and the first driver terminal is coupled to a terminal of the first radiation source and to a terminal of the second radiation source.

10. The biometric sensor arrangement according to claim 7,

wherein the first radiation source is configured to protect the second radiation source in an event of an electrostatic discharge.

11. The biometric sensor arrangement according to claim 1,

wherein the first and the second radiation source are arranged in vicinity and are configured to emit radiation through the same opening of a housing.

12. The biometric sensor arrangement according to claim 1,

wherein the biometric sensor arrangement is configured to determine a heart rate of a user.

13. The biometric sensor arrangement according to claim 1,

wherein the biometric sensor arrangement is configured to determine the concentration of at least one parameter in a skin of a user of a group consisting of melanin, water, fat, alcohol and oxygen.

14. A mobile device, comprising the biometric sensor arrangement according to claim 1,

wherein the mobile device is realized as a mobile telecommunication device or a watch.

15. A method for generating a biometric signal, comprising:

selectively operating a first and a second radiation source by a driver, wherein the second radiation source is implemented as a flash radiation source,

providing a photon signal by a photosensor as a function of radiation emitted by the first radiation source and

providing the biometric signal by a signal conditioning unit as a function of the photon signal,

wherein providing the biometric signal comprises;

receiving the photon signal at a transimpedance amplifier of the signal conditioning unit, and

generating a modified photon signal using an analog-to-digital converter of the signal conditioning unit,

wherein the transimpedance amplifier comprises an operational amplifier and a feedback resistor that couples a first input of the operational amplifier to an output of the operational amplifier;

wherein a terminal of the photosensor is connected to the first input of the operational amplifier, and a second input of the operational amplifier is connected to a reference potential terminal,

wherein the first input of the operational amplifier is an inverting input and the second input of the operational amplifier is a non-inverting input, and

wherein the analog-to-digital converter is coupled to the output of the operational amplifier.

16. A biometric sensor arrangement, comprising:

a first radiation source,

a second radiation source that is implemented as a flash radiation source,

a driver coupled to the first and the second radiation source and configured to selectively operate the first and the second radiation source,

a photosensor and

a signal conditioning unit operable to provide a biometric signal,

wherein the signal conditioning unit comprises a transimpedance amplifier and an analog-to-digital converter,

wherein the transimpedance amplifier comprises an operational amplifier and a feedback resistor that couples a first input of the operational amplifier to an output of the operational amplifier

wherein a terminal of the photosensor is connected to the first input of the operational amplifier,

wherein a second input of the operational amplifier is connected to a reference potential terminal,

wherein the first input of the operational amplifier is an inverting input, and the second input of the operational amplifier is a non-inverting input,

wherein the analog-to-digital converter is coupled to the output of the operational amplifier

wherein the first and the second radiation source are realized as light-emitting diodes and form an anti-parallel circuit of diodes, and

wherein the first radiation source is configured to protect the second radiation source in an event of an electrostatic discharge.