Living being presence detection system

• US 7,417,536 B2
• Filed: 04/25/2006
• Issued: 08/26/2008
• Est. Priority Date: 03/13/2003
• Status: Expired due to Fees

• Current Assignee: Bing Ma, Narasimhamurthi Natarajan, Sridhar Lakshmanan, Srini Naidu
• Original Assignee: Bing Ma, Narasimhamurthi Natarajan, Sridhar Lakshmanan, Srini Naidu
• Inventors: Lakshmanan, Sridhar, Ma, Bing, Naidu, Srini, Natarajan, Narasimhamurthi
• Primary Examiner(s): Pope; Daryl C
• Application Number:
  US11/412,053
• Publication Number:
  US 20070103328A1
• Time in Patent Office: 854 Days
• Field of Search: 340/538, 340/425.5, 340/438, 340/439, 340/457, 340/459, 340/460, 340/461, 701/45, 701/47
• US Class Current: 340/538
• CPC Class Codes: B60R 2021/01322 comprising variable thresholds, e.g. depending from other collision parameters
• CPC Class Codes: B60R 21/01516 using force or pressure sensing means
• CPC Class Codes: B60R 21/0152 using strain gauges
• CPC Class Codes: G08B 7/00 Signalling systems according to more than one of groups G08B3/00 - G08B6/00; Personal calling systems according to more than one of groups G08B3/00 - G08B6/00

Abstract

A system for distinguishing between a first condition corresponding to a living subject being directly in contact with an object of interest, and a second condition corresponding to the absence of contact between the living subject and the object of interest. A transducer, which may be a MEMs sensor, is disposed in predetermined relationship to the object of interest and produces a transducer signal responsive to a pressure wave resulting from the living subject being directly in contact the object of interest. A database stores data corresponding to the first condition and may contain additional data corresponding to the second condition. A processor calculates an algorithm of a non-linear short-term frequency-selective energy distribution of the transducer signal over time to produce transducer signal data. An arrangement, which may be a human listener or a processor system, determines a threshold between the first and second conditions in response to the transducer signal data and the first and second data. The direct contact may be a tap or stroking contact by a living subject. The transducer can be disposed within, or on the exterior of, the object of interest.

Claims

1. A system for distinguishing between a first condition corresponding to a living subject being directly in contact with an object of interest, and a second condition corresponding to the absence of contact between the living subject and the object of interest, the system comprising:

a transducer disposed in predetermined relationship to the object of interest, for producing a transducer signal responsive to a pressure wave resulting from the living subject being directly in contact the object of interest;

a database for storing first data corresponding to the first condition and second data corresponding to the second condition;

a processor for calculating an algorithm corresponding to a non-linear short-term frequency-selective energy distribution of the transducer signal over time to produce corresponding transducer signal data; and

an arrangement for determining a threshold between the first and second conditions in response to the transducer signal data and the first and second data.

2. The system of claim 1, wherein the direct contact between the living subject and the object of interest constitutes a tap contact by the human subject of the object of interest.

3. The system of claim 1, wherein the direct contact between the living subject and the object of interest constitutes a stroke contact by the human subject of the object of interest.

4. The system of claim 1, wherein said transducer comprises an accelerometer.

5. The system of claim 1, wherein said transducer is disposed within the object of interest.

6. The system of claim 1, wherein there is further provided a modulation system for translating a selected frequency component of the transducer signal to a translated frequency within the frequency range between 0 Hz and 20 kHz.

7. The system of claim 6, wherein the translated frequency is within the audible range of a human listener, and there is further provided a training system for training the human listener to distinguish between the first and second conditions.

8. The system of claim 7, wherein the pressure wave corresponds to the heartbeat of the living subject, and the human listener is trained to listen to a signal corresponding to the frequency-translated transducer signal and distinguish between the first and second conditions.

9. The system of claim 8, wherein the signal corresponding to the frequency-translated transducer signal is a tone signal.

10. The system of claim 8, wherein the living subject is a human being.

11. The system of claim 6, wherein said modulation system comprises an amplitude modulator, having a carrier frequency in the range between 20 Hz to 20 kHz.

12. A system for distinguishing between a first condition corresponding to a living subject of a species of interest being directly in contact with an object of interest, and a second condition corresponding to the absence of contact between the living subject and the object of interest, the system comprising:

a transducer disposed in predetermined relationship to the object of interest, for producing a transducer signal responsive to a pressure wave resulting from the heartbeat of the living subject; and

a modulation system for translating the frequency of the transducer signal.

13. The system of claim 12, wherein said modulation system translates the transducer signal to a translated frequency within the frequency range between 0 Hz and 20 kHz.

14. The system of claim 12, wherein there is further provided a filter arrangement for comparing the transducer signal to stored heartbeat data.

15. The system of claim 14, wherein said filter arrangement comprises a database for storing first data corresponding to a heartbeat of the species of the living subject.

16. The system of claim 15, wherein said filtering arrangement further comprises:

a processor for calculating an algorithm corresponding to a non-linear short-term frequency-selective energy distribution of the transducer signal over time to produce corresponding transducer signal data; and

a comparator for comparing the transducer signal data to the first data.

17. The system of claim 15, wherein said filtering arrangement further comprises a processor for calculating an algorithm corresponding to a non-linear short-term frequency-selective energy distribution of the transducer signal over time to produce corresponding transducer signal data.

18. The system of claim 17, wherein said filtering arrangement further comprises an arrangement for determining a threshold between the first and second conditions in response to the transducer signal data and the first data.

19. The system of claim 18, wherein said database additionally stores second data corresponding to the second condition.

20. A system for distinguishing between a first condition corresponding to a living subject of a species of interest being directly in contact with an object of interest, and a second condition corresponding to the absence of contact between the living subject and the object of interest, the system comprising:

a plurality of pressure transducers disposed in predetermined relationship to the object of interest, for producing respective transducer signals responsive to pressure waves resulting from the heartbeat of the living subject;

a database for storing data corresponding to a heartbeat characteristic of the species of the living subject;

a processor for calculating an algorithm corresponding to a non-linear short-term frequency-selective energy distribution of the transducer signals over time, and for comparing the frequency-selective energy distribution of the transducer signals to the data in the database; and

an arrangement for determining a threshold for distinguishing between the first and second conditions.