Living body discriminating apparatus

• US 6,181,808 B1
• Filed: 07/29/1998
• Issued: 01/30/2001
• Est. Priority Date: 07/29/1997
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Fukuzumi, Shinichi
• Primary Examiner(s): Boudreau, Leo H.
• Assistant Examiner(s): Werner, Brian P.
• Application Number:
  US09/124,003
• Time in Patent Office: 916 Days
• Field of Search: 381/16, 381/19--27, 702/19, 702/64, 702/75-78, 356/71, 340/825.34, 324/71.1, 324/76.19, 324/76.21
• US Class Current: 382/126
• CPC Class Codes: A61B 5/389 Electromyography [EMG]
• CPC Class Codes: G06V 40/12 Fingerprints or palmprints
• CPC Class Codes: G06V 40/1394 using acquisition arrangements
• CPC Class Codes: G07C 9/37 using biometric data, e.g. fingerprints, iris scans or voice recognition

Abstract

When a finger 8 is put on a fingerprint input sensor 1, it is held in contact with living body potential deriving electrodes 2₁ and 2₂. In addition, a finger portion near the first joint is held in contact with a living body grounding electrode 3 to ground the living body. With the finger 8 pushed against the fingerprint input sensor 1 for inputting the fingerprint, finger muscle potentials signals 101 to 103 are obtained from these electrodes. A living body data measuring unit 4 takes differences of these finger muscle potentials for one another, and outputs the result as living body data potential data 104. A living body data analyzing unit 5 analyzes the potential data and frequency data of the living body potential difference data 104, and outputs analysis data 105. A living body discriminating unit 6 makes a determination, from the analysis data 105, as to whether the finger 8 is a finger of living body or a replica finger.

Claims

1. A living body discriminating apparatus comprising:

fingerprint input sensor means on which a finger is placed when inputting fingerprint;

a plurality of living body potential deriving means disposed as transparent sensors on the surface of the fingerprint input sensor means for measuring the potential difference between two muscle points of the finger;

living body grounding electrode means provided on the fingerprint input sensor means for grounding the living body;

living body data measuring means for amplifying signals obtained from the living body potential deriving means and the living body grounding electrode means;

living body data analyzing means for performing potential measurement and frequency analysis of living body data obtained in the living body data measuring means by digitizing the data; and

living body discriminating means for discriminating whether the data obtained by processing in the living body data analyzing means is of the living body.

2. The living body discriminating means according to claim 1, wherein three elements are provided as the living body potential deriving means, two of the three elements being used to measure the potential difference between two muscle points of the finger, the remaining one of the elements being used as a living body grounding electrode.

3. The living body discriminating apparatus according to claim 1, wherein the fingerprint input sensor means has a finger guide for holding the finger at a constant position.

4. A living body discriminating apparatus, comprising:

a fingerprint sensor on which a finger is placed for inputting a fingerprint of the finger;

at least two living body potential deriving electrodes, provided on a surface of the fingerprint input sensor, for measuring the potential difference between two points of the muscle of the finger;

a living body ground electrode, disposed on the fingerprint input sensor, for grounding the living body;

a living body data measuring unit for amplifying signals obtained from the living body potential deriving electrodes and the living body grounding electrode;

a living body data analyzing unit for digitizing and frequency analyzing living body data measured in the living body data measuring unit; and

a living body discriminating unit for discriminating whether obtained data is of a living body based on the analyzed result of the living body data analyzing unit,

wherein the living body data measuring unit measures differences of the signals from the two living body potential deriving electrodes and the living body grounding electrode, and a difference between the two differences.

5. A living body discriminating apparatus, comprising:

a fingerprint sensor on which a finger is placed for inputting a fingerprint of the finger;

at least two living body potential deriving electrodes provided on a surface of the fingerprint input sensor, for measuring the potential difference between two points of the muscle of the finger;

a living body ground electrode disposed on the fingerprint input sensor, for grounding the living body;

a living body data measuring unit for amplifying signals obtained from the living body potential deriving electrodes and the living body grounding electrode;

a living body data analyzing unit for digitizing and frequency analyzing living body data measured in the living body data measuring unit; and

a living body discriminating unit for discriminating whether obtained data is of a living body based on the analyzed result of the living body data analyzing unit,

wherein the discrimination of the living body discriminating unit is performed based on the voltage amplitude and frequency range of the analyzed result of the living body data analyzing unit, and

wherein the voltage range is 10 μ

V to 10 mV and the frequency is 2 Hz to 2 kHz.

6. A living body discriminating apparatus, comprising:

a fingerprint sensor on which a finger is placed for inputting a fingerprint of the finger;

at least two living body potential deriving electrodes provided on a surface of the fingerprint input sensor, for measuring the potential difference between two points of the muscle of the finger;

a living body ground electrode disposed on the fingerprint input sensor, for grounding the living body;

a living body data measuring unit for amplifying signals obtained from the living body potential deriving electrodes and the living body grounding electrode;

a living body data analyzing unit for digitizing and frequency analyzing living body data measured in the living body data measuring unit; and

a living body discriminating unit for discriminating whether obtained data is of a living body based on the analyzed result of the living body data analyzing unit,

wherein the discrimination is performed when the potential difference exceeds a first threshold level and does not exceed a second threshold level within a predetermined time period after the first threshold level was exceeded.

7. The living body discriminating means according to claim 6, wherein the frequency data is obtained by removing a power spectrum in a particular frequency band from an overall power spectrum that is obtained by frequency analyzing the living body data as performed by the living body data analyzing unit.

8. The living body discriminating apparatus, comprising:

a fingerprint sensor on which a finger is placed for inputting a fingerprint of the finger;

at least two living body potential deriving electrodes provided on a surface of the fingerprint input sensor, for measuring the potential difference between two points of the muscle of the finger;

a living body ground electrode disposed on the fingerprint input sensor, for grounding the living body;

a living body data measuring unit for amplifying signals obtained from the living body potential deriving electrodes and the living body grounding electrode;

a living body data analyzing unit for digitizing and frequency analyzing living body data measured in the living body data measuring unit; and

a living body discriminating unit for discriminating whether obtained data is of a living body based on the analyzed result of the living body data analyzing unit,

wherein the living body potential deriving electrodes are transparent.