Noninvasive alcohol sensor
View Patent ↗Methods and systems are provided for biometric sensing. An illumination subsystem provides light at discrete wavelengths to a skin site of an individual. A detection subsystem receives light scattered from the skin site. A computational unit is interfaced with the detection system. The computational unit has instructions for deriving a spatially distributed multispectral image from the received light at the discrete wavelengths. The computational unit also has instructions for comparing the derived multispectral image with a database of multispectral images to identify the individual.
1. A method for determining a blood-alcohol level of an individual, the method comprising:
receiving electromagnetic radiation emanating from tissue of the individual in response to propagation of electromagnetic radiation into the tissue of the individual;
deriving a spatially distributed multispectral image from the received electromagnetic radiation;
determining the blood-alcohol level from the multispectral image; and
determining a biometric identification of the individual from the multispectral image.
2. The method recited in claim 1 wherein determining the blood-alcohol level from the multispectral image comprises determining amplitudes of the received electromagnetic radiation within a wavelength range of 2.1-2.5 μm.
3. The method recited in claim 1 wherein determining the blood-alcohol level from the multispectral image comprises determining amplitudes of the received electromagnetic radiation within a wavelength range of 2.2-2.4 μm.
4. The method recited in claim 1 wherein determining the blood-alcohol level from the multispectral image comprises determining amplitudes of the received electromagnetic radiation at one or more wavelength values approximately equal to values selected from the group consisting of 2.23 μm, 2.26 μm, 2.28 μm, 2.30 μm, 2.32 μm, 2.25 μm, and 2.38 μm.
5. The method recited in claim 1 wherein determining the blood-alcohol level from the multispectral image comprises determining amplitudes of the received electromagnetic radiation within a wavelength range of 1.5-1.9 μm.
6. The method recited in claim 1 wherein determining the blood-alcohol level from the multispectral image comprises determining amplitudes of the received electromagnetic radiation within a wavelength range of 1.6-1.8 μm.
7. The method recited in claim 1 wherein determining the blood-alcohol level from the multispectral image comprises determining amplitudes of the received electromagnetic radiation at one or more wavelength values approximately equal to values selected from the group consisting of 1.67 μm, 1.69 μm, 1.71 μm, 1.73 μm, 1.74 μm 1.76 μm and 1.78 μm.
8. The method recited in claim 1 wherein determining the blood-alcohol level from the multispectral image comprises correcting for optical drift of the received electromagnetic radiation.
9. The method recited in claim 8 wherein correcting for optical drift comprises measuring electromagnetic radiation emanating from a reference sample in response to propagation of electromagnetic radiation into the reference sample.
10. The method recited in claim 9 wherein the reference sample comprises a mixture of alcohol and water.
11. The method recited in claim 9 wherein measuring electromagnetic radiation emanating from the reference sample comprises measuring electromagnetic radiation within a wavelength range of 2.1-2.5 μm.
12. The method recited in claim 9 wherein measuring electromagnetic radiation emanating from the reference sample comprises measuring electromagnetic radiation within a wavelength range of 1.5-1.9 μm.
13. The method recited in claim 1 further comprising taking an action in response to a determination that the blood-alcohol level of the individual is outside a prescribed range.
14. The method recited in claim 13 wherein taking the action comprises prohibiting ignition of a motor vehicle.
15. The method recited in claim 1 further comprising making a biometric identification of the individual.
16. The method recited in claim 15 wherein making a biometric identification of the individual comprises comparing a spectral variation of the received electromagnetic radiation with a previously stored spectral variation.
17. The method recited in claim 15 further comprising taking an action in response to a combination of the determined blood-alcohol level and the biometric identification of the individual.
18. The method recited in claim 15 wherein:
the electromagnetic radiation is propagated into the tissue of the individual at a skin site with a plurality of discrete wavelengths; and
making the biometric identification of the individual comprise comparing the multispectral image with a database of multispectral images.
19. Apparatus for determining a blood-alcohol level of an individual, the apparatus comprising:
a receiver adapted to receive electromagnetic radiation emanating from tissue of the individual in response to propagation of electromagnetic radiation into the tissue of the individual;
a processor coupled with the receiver; and
a computer-readable storage medium coupled with a processor, the computer-readable storage medium having a computer-readable program embodied therein for directing operation of the processor, the computer-readable program including:
instructions for deriving a spatially distributed multispectral image from the received electromagnetic radiation;
instructions for determining the blood-alcohol level from the multispectral image; and
instructions for determining a biometric identification of the individual from the multispectral image.
20. The apparatus recited in claim 19 wherein the receiver comprises a sensor and an optical bandpass filter adapted to propagate light having a wavelength range of 2.1-2.5 μm.
21. The apparatus recited in claim 19 wherein the receiver comprises a plurality of sensors and a plurality of optical bandpass filters adapted to propagate light at a wavelength values approximately equal to values selected from the group consisting of 2.23 μm, 2.26 μm, 2.28 μm, 2.30 μm, 2.32 μm, 2.25 μm, and 2.38 μm.
22. The apparatus recited in claim 19 wherein the receiver comprises a sensor and an optical bandpass filter adapted to propagate light having a wavelength range of 1.5-1.9 μm.
23. The apparatus recited in claim 19 wherein the receiver comprises a plurality of sensors and a plurality of optical bandpass filters adapted to propagate light at a wavelength values approximately equal to values selected from the group consisting of 1.67 μm, 1.69 μm, 1.71 μm, 1.73 μm, 1.74 μm 1.76 μm and 1.78 μm.
24. The apparatus recited in claim 19 wherein the receiver comprises:
a variable filter; and
a detector array.
25. The apparatus recited in claim 24 wherein the detector array comprises a semiconductor detector array.
26. The apparatus recited in claim 24 wherein the detector array comprises a pyroelectric detector array.
27. The apparatus recited in claim 24 wherein the detector array comprises a bolometer detector array.
28. The apparatus recited in claim 19 further comprising a source of electromagnetic radiation adapted to propagate electromagnetic radiation into the tissue of the individual.
29. The apparatus recited in claim 28 wherein the source comprises a light-emitting diode.
30. The apparatus recited in claim 28 wherein the source comprises a laser diode.
31. The apparatus recited in claim 30 wherein the laser diode is tunable.
32. The apparatus recited in claim 19 wherein the computer-readable program further includes instructions for making a biometric identification of the individual from the received electromagnetic radiation.
33. The apparatus recited in claim 19 further comprising a biometric device adapted to make a biometric identification of the individual.
34. The apparatus recited in claim 33 wherein:
the electromagnetic radiation is propagated into the tissue of the individual at a skin site with a plurality of discrete wavelengths; and
the computer-readable program further includes instructions for comparing the multispectral image with a database of multispectral images.
35. The apparatus recited in claim 33 wherein the biometric identification is a nonoptical biometric identification.
36. A key fob comprising the apparatus recited in claim 19 .
37. A motor vehicle comprising the apparatus recited in claim 19 .
38. The method of claim 1 , wherein determining the biometric identification occurs substantially contemporaneously with determining the blood-alcohol level.
39. The method of claim 1 , wherein determining the biometric identification occurs in spatial proximity to determining the blood-alcohol level.