Compact light sensor

Patent metadata

Field	Value
Publication number	US-9746377-B2
Application number	US-201615352504-A
Country	US
Kind code	B2
Filing date	Nov 15, 2016
Priority date	Mar 21, 2014
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

Provided are methods and systems for concurrent imaging at multiple wavelengths. In one aspect, a hyperspectral/multispectral imaging device includes a lens configured to receive light backscattered by an object, a plurality of photo-sensors, a plurality of bandpass filters covering respective photo-sensors, where each bandpass filter is configured to allow a different respective spectral band to pass through the filter, and a plurality of beam splitters in optical communication with the lens and the photo-sensors, where each beam splitter splits the light received by the lens into a plurality of optical paths, each path configured to direct light to a corresponding photo-sensor through the bandpass filter corresponding to the respective photo-sensor.

First claim

What is claimed is:

1. An imaging device configured to collect a set of eight to twelve images for determining oxyhemoglobin and deoxyhemoglobin content of a tissue, comprising:
a light source,
a lens configured to receive light that has been emitted from the at least one light source and backscattered by the tissue,
a plurality of photo-sensors in optical communication with the lens and configured to collect the set of eight to twelve images of the tissue, and
a plurality of multi-bandpass filters, wherein each respective multi-bandpass filter in the plurality of multi-bandpass filters covers a corresponding photo-sensor in the plurality of photo-sensors thereby selectively allowing a different corresponding spectral band of light, from the light received by the lens, to pass through to the corresponding photo-sensor; wherein
each image in the set of eight to twelve images is collected at a discrete spectral band, and
the set of eight to twelve images comprises images collected at any seven or more spectral bands of a predetermined set of spectral bands having central wavelengths: 520±5 nm, 540±5 nm, 560±5 nm, 580±5 nm, 590±5 nm, 610±5 nm, 620±5 nm, and 640±5 nm.

2. The imaging device of claim 1 , wherein each respective spectral band in the predetermined set of spectral bands has a full width at half maximum of less than 15 nm.

3. The imaging device of claim 1 , wherein:
the light source comprises a first light source and a second light source,
the first light source emits light that is substantially limited to a first spectral range, wherein the first spectral range encompasses a first subset of the predetermined set of spectral bands, and
the second light source emits light that is substantially limited to a second spectral range, wherein the second spectral range encompasses those spectral bands in the predetermined set of spectral bands other than the first subset of the predetermined set of spectral bands.

4. The imaging device of claim 3 , wherein:
the first light source is a first multi-spectral light source covered by a first bandpass filter, wherein the first bandpass filter substantially blocks all light emitted by the first light source other than the first spectral range, and
the second light source is a second multi-spectral light source covered by a second bandpass filter, wherein the second bandpass filter substantially blocks all light emitted by the second light source other than the second spectral range.

5. The imaging device of claim 4 , wherein the first multi-spectral light source is a first white light emitting diode and the second multi-spectral light source is a second white light emitting diode.

6. The imaging device of claim 3 , wherein:
each respective multi-bandpass filter in the plurality of multi-bandpass filters is configured to selectively allow light corresponding to either of two discrete spectral bands to pass through to the corresponding photo-sensor,
a first of the two discrete spectral bands corresponds to a first spectral band that is represented in the first spectral range and not in the second spectral range, and a second of the two discrete spectral bands corresponds to a second spectral band that is represented in the second spectral range and not in the first spectral range.

7. The imaging device of claim 3 , further comprising an optical path assembly comprising a plurality of beam splitters in optical communication with the lens and the plurality of photo-sensors; wherein:
each respective beam splitter in the plurality of beam splitters is configured to split the light received by the lens into at least two optical paths,
a first beam splitter in the plurality of beam splitters is in direct optical communication with the lens and a second beam splitter in the plurality of beam splitters is in indirect optical communication with the lens through the first beam splitter, and
the plurality of beam splitters collectively split light received by the lens into a plurality of optical paths, wherein each respective optical path in the plurality of optical paths is configured to direct light to a corresponding photo-sensor in the plurality of photo-sensors through the respective multi-bandpass filter covering the corresponding photo-sensor.

8. The imaging device of claim 7 , wherein each beam splitter in the plurality of beam splitters exhibits a ratio of light transmission to light reflection of about 50:50 and is a wavelength-independent beam splitter.

9. The imaging device of claim 7 , further comprising a controller configured to capture a plurality of images from the plurality of photo-sensors by performing a method including:
(A) illuminating the tissue a first time using the first light source;
(B) capturing a first collection of images with the plurality of photo-sensors during the illuminating (A), wherein the first collection of images includes, for each respective photo-sensor in the plurality of photo-sensors, an image corresponding to a first spectral band transmitted by the corresponding multi-bandpass filter, wherein the light falling within the first spectral range includes light falling within the first spectral band of each multi-bandpass filter in the plurality of multi-bandpass filters;
(C) extinguishing the first light source;
(D) illuminating the tissue a second time using the second light source; and
(E) capturing a second collection of images with the plurality of photo-sensors during the illuminating (D), wherein the second collection of images includes, for each respective photo-sensor in the plurality of photo-sensors, an image corresponding to a second spectral band transmitted by the corresponding multi-bandpass filter, wherein the light falling within the second spectral range includes light falling within the second spectral band of each multi-bandpass filter in the plurality of multi-bandpass filters.

10. The imaging device of claim 9 , wherein:
each respective photo-sensor in the plurality of photo-sensors is a pixel array that is controlled by a corresponding shutter mechanism that determines an image integration time for the respective photo-sensor, and
a first photo-sensor in the plurality of photo-sensors is independently associated with a first integration time for use during the capturing (B) and a second integration time for use during the capturing (E), wherein the first integration time is independent of the second integration time.

11. The imaging device of claim 9 , wherein
each respective photo-sensor in the plurality of photo-sensors is a pixel array that is controlled by a corresponding shutter mechanism that determines an image integration time for the respective photo-sensor,
a duration of the illuminating (A) is determined by a first maximum integration time associated with the plurality of photo-sensors during the capturing (B), wherein an integration time of a first photo-sensor in the plurality of photo-sensors is different than an integration time of a second photo-sensor in the plurality of photo-sensors during the capturing (B),
a duration of the illuminating (D) is determined by a second maximum integration time associated with the plurality of photo-sensors during the capturing (E), wherein an integration time of the first photo-sensor is different than an integration time of the second photo-sensor during the capturing (E), and
the first maximum integration time is different than the second maximum integration time.

12. The imaging device of claim 9 , wherein each image in the plurality of images is a multi-pixel image of the tissue and the method performed by the controller further comprises:
(F) combining each image in the plurality of images, on

Assignees

• Hypermed Imaging Inc

Inventors

• Darty Mark Anthony
• Tilleman Michael
• Meenen Peter
• Yudovsky Dmitry

Classifications

• G01J3/0294 Primary

  Multi-channel spectroscopy · CPC title

• H04N23/56

  provided with illuminating means · CPC title

• G01J3/0291 Primary

  Housings; Spectrometer accessories; Spatial arrangement of elements, e.g. folded path arrangements · CPC title

• H04N23/74

  by influencing the scene brightness using illuminating means · CPC title

• H04N23/55

  Optical parts specially adapted for electronic image sensors; Mounting thereof · CPC title