Near-infrared time-of-flight remote sensing

• US 10,386,230 B1
• Filed: 11/12/2018
• Issued: 08/20/2019
• Est. Priority Date: 12/31/2012
• Status: Expired due to Fees

• Current Assignee: Omni Medsci, Inc.
• Original Assignee: Omni Medsci, Inc.
• Inventors: Islam, Mohammed N.
• Primary Examiner(s): Rahman, Md M
• Application Number:
  US16/188,194
• Time in Patent Office: Days
• Field of Search: 356300
• 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 2562/146 for optical coupling
• CPC Class Codes: A61B 2576/02 specially adapted for a particular organ or body part
• CPC Class Codes: A61B 5/0013 Medical image data A61B1/00011, A61B6/56, A61B8/56 take precedence
• CPC Class Codes: A61B 5/0022 Monitoring a patient using a global network, e.g. telephone networks, internet
• CPC Class Codes: A61B 5/0075 by spectroscopy, i.e. measuring spectra, e.g. Raman spectroscopy, infrared absorption spectroscopy A61B5/0071 takes precedence
• CPC Class Codes: A61B 5/0086 using infrared radiation
• CPC Class Codes: A61B 5/0088 for oral or dental tissue
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/4547 Evaluating teeth
• CPC Class Codes: G01J 2003/104 Monochromatic plural sources
• CPC Class Codes: G01J 2003/2826 Multispectral imaging, e.g. filter imaging
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/108 for measurement in the infrared range
• CPC Class Codes: G01J 3/14 using refracting elements, e.g. prisms G01J3/18, G01J3/26 take precedence prisms per se G02B5/04
• CPC Class Codes: G01J 3/1838 Holographic gratings
• CPC Class Codes: G01J 3/28 Investigating the spectrum using colour filters G01J3/51
• CPC Class Codes: G01J 3/2823 : Imaging spectrometer
• CPC Class Codes: G01J 3/42 : Absorption spectrometry; Double beam spectrometry; Flicker spectrometry; Reflection spectrometry beam switching arrangements G01J3/08
• CPC Class Codes: G01J 3/453 : by correlation of the amplitudes
• CPC Class Codes: G01M 3/38 : by using light G01M3/02 takes precedence
• CPC Class Codes: G01N 2021/3513 : Open path with an instrumental source
• CPC Class Codes: G01N 2021/399 : Diode laser
• CPC Class Codes: G01N 21/3504 : for analysing gases, e.g. multi-gas analysis
• CPC Class Codes: G01N 21/3563 : for analysing solids; Preparation of samples therefor
• CPC Class Codes: G01N 21/359 : using near infrared light
• CPC Class Codes: G01N 21/39 : using tunable lasers
• CPC Class Codes: G01N 21/88 : Investigating the presence of flaws or contamination
• CPC Class Codes: G01N 2201/061 : Sources
• CPC Class Codes: G01N 2201/062 : LED's
• CPC Class Codes: G01N 2201/08 : Optical fibres; light guides
• CPC Class Codes: G01N 2201/12 : Circuits of general importance; Signal processing
• CPC Class Codes: G01N 33/02 : Food
• CPC Class Codes: G01N 33/15 : Medicinal preparations ; Physical properties thereof, e.g. dissolubility drug screening with animal cells G01N33/5008
• CPC Class Codes: G01N 33/442 : Resins, plastics
• CPC Class Codes: G01N 33/49 : Blood chemical methods for determining blood cell populations G01N33/5094; chemical analysis of blood groups or blood types G01N33/80
• CPC Class Codes: H01S 3/302 : in an optical fibre

Abstract

A smart phone or tablet includes laser diodes configured to be pulsed and generate near-infrared light between 700-2500 nanometers. Lenses direct the light to a sample. A detection system includes a photodiode array with pixels coupled to CMOS transistors, and is configured to receive light reflected from the sample, to be synchronized to the light from the laser diodes, and to perform a time-of-flight measurement of a time difference between light from the laser diodes and light reflected from the sample. The detection system is configured to convert light received while the laser diodes are off into a first signal, and light received while at least one laser diodes is on, which includes light reflected from the sample, into a second signal. The smart phone or tablet is configured to difference the first signal and the second signal and to generate a two-dimensional or three-dimensional image using the time-of-flight measurement.

Claims

1. A remote sensing system, comprising:

an array of laser diodes configured to generate light having an initial light intensity and one or more optical wavelengths, wherein at least a portion of the one or more optical wavelengths is a near-infrared wavelength between 700 nanometers and 2500 nanometers, and wherein at least a portion of the array of laser diodes is configured to be pulsed at a modulation frequency;

one or more lenses, and one or more scanners comprising moving mirrors configured to receive a portion of the light from the array of laser diodes and to direct the portion of the light from the array of laser diodes to an object, wherein the moving mirrors are configured to scan the received portion of the light across at least a part of the object;

a detection system comprising a photodiode array with a plurality of pixels coupled to CMOS transistors;

wherein the detection system is configured to receive at least a portion of light reflected from the object, wherein the detection system is configured to be synchronized to the at least a portion of the array of laser diodes configured to be pulsed, and wherein the detection system is configured to use a lock-in technique that detects the modulation frequency;

wherein the detection system is further configured to perform a time-of-flight measurement by measuring a time difference between the generated light from the at least a portion of the array of laser diodes and the at least a portion of light reflected from the object, wherein the detection system further comprises one or more filters to select at least some of the one or more optical wavelengths;

wherein the remote sensing system is configured to generate a two-dimensional or three-dimensional mapping using at least a portion of the time-of-flight measurement;

wherein the remote sensing system is configured to improve signal-to-noise ratio of at least a portion of the two-dimensional or three-dimensional mapping by increasing light intensity of the array of laser diodes relative to the initial light intensity; and

wherein the remote sensing system is adapted to be mounted on a vehicle, and wherein the at least a portion of the two-dimensional or three-dimensional mapping is combined with global positioning system information.

2. The remote sensing system of claim 1, wherein the at least a portion of the one or more optical wavelengths falls within an eye safe window corresponding to an optical wavelength longer than 1400 nanometers.

3. The remote sensing system of claim 1, wherein the detection system is configured to perform filtering at the modulation frequency, wherein the modulation frequency has a phase, and wherein the detection system is configured to lock onto the phase.

4. The remote sensing system of claim 1, wherein at least one laser diode in the array of laser diodes emits at a first wavelength and at least another laser diode in the array of laser diodes emits at a second wavelength different from the first wavelength, and wherein the two-dimensional or three-dimensional mapping is generated in part by comparing at least a portion of light at the first wavelength reflected from the object with at least a portion of light at the second wavelength reflected from the object.

5. The remote sensing system of claim 1, wherein at least a portion of the array of laser diodes comprises one or more distributed Bragg reflectors.

6. The remote sensing system of claim 1, wherein the detection system is further configured to:

generate a first signal responsive to light received while the array of laser diodes is off; and

generate a second signal responsive to light received while at least part of the array of laser diodes is on, the light received while at least part of the array of laser diodes is on including at least some light reflected from the object;

and

wherein the remote sensing system is configured to difference the first signal and the second signal and to generate the two-dimensional or three-dimensional mapping at least in part based on the difference.

7. A remote sensing system, comprising:

a plurality of laser diodes configured to generate light having an initial light intensity and one or more optical wavelengths, wherein at least a portion of the one or more optical wavelengths is a near-infrared wavelength between 700 nanometers and 2500 nanometers, and wherein at least a portion of the plurality of laser diodes is configured to be pulsed;

one or more scanners comprising moving mirrors configured to receive a portion of the light from the plurality of laser diodes and to direct the received portion of light from the plurality of laser diodes to an object, wherein the moving mirrors are configured to scan the received portion of light across at least a part of the object;

a detection system comprising a plurality of photodiodes with a plurality of pixels coupled to CMOS transistors;

wherein the detection system is configured to receive at least a portion of light reflected from the object, and wherein the detection system is configured to be synchronized to the at least a portion of the plurality of laser diodes configured to be pulsed;

wherein the detection system is configured to perform a time-of-flight measurement by measuring a time difference between the generated light from the at least a portion of the plurality of laser diodes configured to be pulsed and the at least a portion of light reflected from the object, and wherein the detection system further comprises one or more filters to select at least some of the one or more optical wavelengths;

wherein the remote sensing system is configured to generate a two-dimensional or three-dimensional mapping using at least a portion of the time-of-flight measurement;

wherein the remote sensing system is configured to improve signal-to-noise ratio of the two-dimensional or three-dimensional mapping by increasing light intensity of at least some of the plurality of laser diodes relative to the initial light intensity of the plurality of laser diodes; and

wherein the remote sensing system is adapted to be mounted on a vehicle.

8. The remote sensing system of claim 7, wherein at least one of the plurality of laser diodes emits at a first wavelength and at least another of the plurality of laser diodes emits at a second wavelength different from the first wavelength, and wherein the two-dimensional or three-dimensional mapping is generated in part by comparing at least a portion of light reflected from the object at the first wavelength with at least a portion of light reflected from the object at the second wavelength.

9. The remote sensing system of claim 7, wherein the two-dimensional or three-dimensional mapping is combined with global positioning system information.

10. The remote sensing system of claim 7, wherein the one or more optical wavelengths fall within an eye safe window corresponding to optical wavelengths longer than 1400 nanometers.

11. The remote sensing system of claim 7, wherein the at least a portion of the plurality of laser diodes has a modulation frequency, and wherein the detection system is configured to use a lock-in technique that detects the modulation frequency.

12. The remote sensing system of claim 11, wherein the detection system is configured to perform filtering at the modulation frequency, wherein the modulation frequency has a phase, and wherein the detection system is configured to lock onto the phase.

13. The remote sensing system of claim 7, wherein at least some of the plurality of laser diodes comprise an array of laser diodes configured as a laser diode bar, and wherein the detection system further comprises an infrared camera.

14. The remote sensing system of claim 7, wherein at least some of the plurality of laser diodes comprise one or more distributed Bragg reflectors.

15. The remote sensing system of claim 7, wherein the detection system is further configured to:

receive light while the plurality of laser diodes is off and convert the received light into a first signal; and

receive light while at least one of the plurality of laser diodes is on and convert the received light while the at least one of the plurality of laser diodes is on into a second signal, the received light including at least some light reflected from the object;

and

wherein the remote sensing system is configured to generate the two-dimensional or three-dimensional mapping at least in part by differencing the first signal and the second signal.

16. A remote sensing system, comprising:

a plurality of laser diodes configured to generate light having an initial light intensity and one or more optical wavelengths, wherein at least a portion of the one or more optical wavelengths is a near-infrared wavelength between 700 nanometers and 2500 nanometers, and wherein at least a portion of the plurality of laser diodes is configured to be pulsed at a modulation frequency;

one or more lenses and one or more scanners, the one or more scanners comprising moving mirrors configured to receive a portion of the light from the plurality of laser diodes and to direct the portion of the light from the plurality of laser diodes to an object, wherein the moving mirrors are configured to scan the received portion of light across at least a part of the object;

a detection system comprising a plurality of photodiodes coupled to CMOS transistors;

wherein the detection system is configured to receive at least a portion of light reflected from the object, wherein the detection system is configured to be synchronized to the at least a portion of the plurality of laser diodes configured to be pulsed, and wherein the detection system is configured to use a lock-in technique that detects the modulation frequency;

wherein the detection system is further configured to perform a time-of-flight measurement by measuring a time difference between the generated light from the at least a portion of the plurality of laser diodes configured to be pulsed and the at least a portion of light reflected from the object, wherein the detection system further comprises one or more filters to select at least a fraction of the one or more optical wavelengths;

wherein the remote sensing system is configured to generate a two-dimensional or three-dimensional mapping at least in part based on the time-of-flight measurement;

wherein the remote sensing system is configured to improve signal-to-noise ratio of the two-dimensional or three-dimensional mapping by increasing light intensity relative to the initial light intensity of the plurality of laser diodes; and

wherein the remote sensing system is adapted to be mounted on a vehicle, and wherein the two-dimensional or three-dimensional mapping is associated with global positioning system information.

17. The remote sensing system of claim 16, wherein the one or more optical wavelengths have optical wavelengths within an eye safe window corresponding optical wavelengths longer than 1400 nanometers.

18. The remote sensing system of claim 17, wherein at least one of the plurality of laser diodes emits at a first wavelength and at least another one of the plurality of laser diodes emits at a second wavelength different from the first wavelength, and wherein the two-dimensional or three-dimensional mapping is generated in part by comparing at least a portion of light at the first and second wavelengths reflected from the object.

19. The remote sensing system of claim 18, wherein at least some of the plurality of laser diodes comprise one or more distributed Bragg reflectors.

20. The remote sensing system of claim 19, wherein the detection system is further configured to generate the two-dimensional or three-dimensional mapping at least in part by differencing a first signal associated with light received by the detection system while all of the plurality of laser diodes are off and a second signal associated with light received while at least one of the plurality of laser diodes is on, the light received while at least one of the laser diodes is on including at least some light reflected from the object.