This invention relates to imaging devices. More particularly, in one embodiment, the invention is directed to a miniature imaging device and related methods.
Spectral analysis of living tissue can be used to detect various forms of cancer and other types of diseases. In spectral analysis, light illuminates a tissue region under examination and a light detector detects optical properties of the illuminated tissue region by measuring light energy modified by its interaction with the tissue region in a pre-determined frequency and amplitude domain. Optical properties include absorption, luminescence, fluorescence, frequency and time domain response to various materials injected to the tissue region and other electromagnetic responses. Diseased tissue may be identified by comparing a spectrum obtained to spectra of normal tissue obtained under the same controlled conditions.
Traditional image sensors include a two dimensional array of photo-detectors (pixels) that are accessed individually by electronics on the same chip, or external to the chip. A black and white image is formed by digitizing the amplitude of each pixel, which creates a gray scale. Color images function in a similar manner, but employ complex algorithms to compute the color. One common color sensor has a color mask that is placed on the image sensor. The color mask is a light filter that allows only certain light wavelengths to penetrate and reach the detector. Then, by comparing amplitudes of adjacent pixels, the color is calculated.
One disadvantage of conventional image sensors is size due to the number of pixels (photo-detectors) required to produce a quality image. Another disadvantage of conventional image sensors is the complex electronics involved in addressing each pixel (photo-detector).
In one embodiment, the invention combines a scanning system similar to a display-type raster scan with a single photodiode to create an image. By doing so, the invention provides an imaging device that is smaller than traditional imaging devices.
According to one embodiment, the imaging device of the invention includes a light source unit, a photo-sensor and a scanning assembly. The light source unit is fixedly mounted in the first end of an elongated sheath and is adapted for illuminating a target. The photo-sensor is mounted on the scanning assembly, also located in the first end of the elongated sheath, and is adapted to detect light energy from the target. The scanning assembly scans the target to enable the photo-sensor to detect light energy from each of a plurality of locations on the target. According to a further embodiment, the imaging device of the invention synchronously digitizes the output from the photo-sensor from each of the plurality of locations on the target to generate an image of the target. According to a further embodiment, the light source unit provides wide angle/divergent illumination. According to one embodiment, the light energy includes reflected light. According to another embodiment, the light energy contains fluorescent light.
According to another embodiment, the scanning assembly includes a platform movably mounted on a constant velocity pivot joint adapted for enabling the scanning assembly to scan the target with a photo-sensor in two directions. According to one embodiment, the scanning assembly is adapted to scan the target at a sweep frequency of greater than or equal to about 1 kHz. According to a further embodiment, the scanning assembly is adapted to scan a target at a sweep frequency above about 5 kHz. According to a further embodiment, the scanning assembly is adapted to scan a target at a sweep frequency above about 10 kHz. According to a further embodiment, the scanning assembly is adapted to scan a target at a sweep frequency above about 15 kHz. According to another embodiment, the scanning assembly is adapted to completely scan the target at a scan frequency of greater than or equal to about 2 Hz. According to a further embodiment, the scanning assembly is adapted to completely scan a target at a scan frequency above about 5 Hz. According to a further embodiment, the scanning assembly is adapted to completely scan a target at a scan frequency above about 10 Hz. According to a further embodiment, the scanning assembly is adapted to completely scan a target at a scan frequency above about 20 Hz. According to a further embodiment, the scanning assembly is adapted to completely scan a target at a scan frequency above about 30 Hz. According to a further embodiment, the scanning assembly is adapted to completely scan a target at a scan frequency above about 40 Hz. According to a further embodiment, the scanning assembly is adapted to completely scan a target at a scan frequency above about 50 Hz. However, various sweep and scan frequencies may be employed without deviating from the scope of the invention. According to a further embodiment, the scanning assembly includes electromagnetic actuators for controlling platform movement. According to an alternative embodiment, the scanning assembly includes piezoelectric actuators for controlling the platform movement. According to another alternative embodiment, the scanning assembly includes microelectronic machine (MEMS) actuators for controlling the platform movement.
According to one feature, the MEMS actuators are fabricated in silicon, which is also a common substrate material for both photo-sensors and lasers diodes. The photo-sensor and/or the laser diode may be fabricated directly on the MEMS actuator plate using standard semiconductor processing techniques. This reduces the need for bonding discrete parts to the scanning platform, with the advantage that it may reduce the overall mass of the platform, allowing for higher scan rates and lower drive power. According to a further embodiment, the photo-sensor is a single pixel photo-sensor.
According to one embodiment, the imaging device includes an aperture oriented with respect to the photo-sensor and adapted for limiting light energy from the target from impinging on the photo-sensor. According to one feature, the aperture allows substantially only the light energy from one target location at a time to impinge on the photo-sensor. According to another feature, the aperture includes a fixed focal length lens.
According to an alternative embodiment, the imaging device of the invention includes a light source unit, a photo-sensor and a scanning assembly, wherein both the light source unit and the photo-sensor are movably mounted on a scanning assembly in the first end of an elongated sheath. The light source illuminates the target as the scanning assembly scans a plurality of locations on the target. The photo-sensor synchronously captures the light energy from each of the scanned locations on the target. The imaging device of the invention then synchronously digitizes the output from the photo-sensor from each of the plurality of locations on the target to generate an image of the target.
According to another alternative embodiment, the imaging device of the invention includes a light source unit, a photo-sensor and a scanning assembly, wherein the photo-sensor is fixedly mounted on a platform in the first end of an elongated sheath and the light source is movably mounted on a scanning assembly, also in the first end of the sheath. According to one feature of this embodiment, the scanning assembly scans the target to discretely illuminate each of a plurality locations on the target. According to a further feature, the photo-sensor synchronously captures the light energy from each of the illuminated locations. According to another feature the imaging device of the invention then digitizes the output from the photo-sensor from each location on the target to generate an image of the target.
According to one embodiment, the light source employs one or more LEDs. According to another embodiment, the light source employs one or more laser diodes. In a further embodiment, the light source unit employs a fixed focal length lens to focus the light onto discrete locations of the target. According to a further embodiment, the photo-sensor employs a wide angle lens to capture light energy from each of the scanned locations on the target.
According to a further embodiment, the first end of the elongated sheath forms a lens adapted for focussing the light from the light source on to each of the scanned locations on the target. According to another embodiment, the first end of the elongated sheath forms a lens adapted for focussing light energy from each of the scanned locations on the target back on to the photo-sensor.
According another alternative embodiment, the invention provides a scanning system having a light source and a photo-sensor, both located discretely from a first end of an elongated sheath to illuminate a location on a target. A beam splitter/combiner couples light from the light source through a fiber optic connection to an end of the fiber optic connection located in the first end of the elongated sheath. The beam splitter/combiner also couples light energy from the target through the first end of the elongated sheath and the same fiber optic connection to the photo-sensor. According to a further embodiment, the scanning system includes a scanning mechanism, located in the first end of the elongated sheath and adapted for moving the end of the fiber optic connection to scan synchronously light from the source onto each of a plurality of locations on the target, and to transfer light energy from each of the plurality of locations on the target back to the photo-sensor. According to a further feature, the scanning system of the invention synchronously digitizes the output from the photo-sensor due to each of the plurality of scanned locations on the target to generate an image of the target.
According to another embodiment, the invention provides a scanning system adapted for generating color images of a target. According to one embodiment, the scanning system of the invention employs field sequenced color (e.g., red, blue, green) LEDs pulsed in sequence for each of the plurality of locations illuminated on the target to achieve a color image of the target. According to one preferred embodiment, the imaging devices and methods of the invention are particularly adapted for analysis of living tissue.
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawings will be provided by the Office upon request and payment of the necessary fee.
The foregoing and other objects of the invention and the various features thereof may be more fully understood from the following description when read together with the accompanying drawings in which like reference designations generally refer to the same or similar parts throughout the different views and in which the depicted components are not necessarily drawn to scale.
As described in summary above, the invention, in one embodiment, is directed to a miniature imaging device. In one embodiment, the imaging device is located in the tip of an elongate sheath such as a catheter. The sheath may be inserted into a human body to observe images of target tissue. According to one embodiment, the imaging device of the invention is employed where conventional endoscopes are too large to be useful.
The photo-sensor assembly 124 fixedly mounts on a platform 126. The platform 126, in turn, movably mounts the base 128 by way of a universal pivot joint 130. The universal pivot joint 130 enables the platform 126 to move in both the x and y-axes. The actuators 132a, 132b, 133a and 133b actuate the movement of the platform 126 with respect to the base 128. More particularly, the actuators 132a and 132b actuate the platform 126 along the x-axis and the actuators 133a and 133b actuate the platform 126 along the y-axis. In one embodiment, the actuators are processor controlled. According to one preferred embodiment, the actuators are electromagnetic. However, according to other embodiments, the actuators may be MEMs or piezoelectric actuators. Control signals are transmitted to the actuators 132a, 132b, 133a and 133b via scan control wires (e.g., 131a and 131b).
According to the illustrative embodiment, the actuators 132a, 132b, 133a and 133b actuate the platform 126 in a predefined pattern (e.g., spiral, circle, raster scan or the like) to scan the target 136 to enable the photo-sensor assembly 124 to detect light energy from each of a plurality of locations on the target 136. The detected light may be, for example, fluorescent or reflected light and may be from anywhere in the spectrum, including visible and infrared. In one embodiment, the actuators 132a, 132b, 133a and 133b are pulsed to cause the platform 126 to move. In a further embodiment, the actuators are operated at resonance to reduce the power necessary to actuate the platform. According to the illustrative embodiment, the photo-sensor assembly 124 includes a photo-sensor 124a (preferably a single photo-diode) and a focussing lens and/or aperture 124b. The focussing lens or aperture 124b limits the amount of light energy from the target allowed to impinge on the photo-sensor 124a. According to one feature, the lens/aperture 124b allows only the light energy from one target location at a time to impinge on the photo-sensor 124a. Optionally, the photo-sensor assembly 124 includes a mask on the photo-sensor 124a to further narrow the field of view (i.e., the selectivity). According to another feature, the lens is a fixed focal length converging lens. In one embodiment, the lens is a gradient index lens. According to another feature, the end 134 of the elongated sheath 139 forms or includes a lens 140 for assisting in providing light from the source assemblies to the target 136 and/or focussing light energy from the target 136 back to the photo-sensor 124a.
According to a further feature, the illustrative imaging device 120 synchronizes the motion with the capture circuitry and digitizes the output from the photo-sensor 124a for each of the plurality of locations (e.g., 138) on the target 136 to generate an image of the target 136.
According to one embodiment, the illustrative imaging device is about one millimeter square in size and provides about one hundred micron resolution.
According to the illustrative embodiment of
According to the embodiment of
Although the above embodiments describe scanning the target directly, in alternative embodiments, a lens, such as the lens 140, may be employed for image reduction. Then, the reduced image may be scanned. In this way, the necessary excursion of the platform 126 and the scan time can be reduced.
As can be seen from the above illustrative embodiments, the invention provides a photo-sensor device that is inexpensive to manufacture and smaller than the current technology. In one embodiment, the invention employs a single miniature detector as opposed to an array of detectors, or bundles of fibers. One problem solved by the invention is that it can go into areas of the human body that an endoscope cannot. Additionally, since the device of the invention is inexpensive to make, it can be disposable. Additionally, the devices of the illustrative embodiments may be employed with any available display technology.
This application is based on prior provisional patent application Ser. No. 60/347,391, filed on Jan. 9, 2002, the benefit of the filing date of which is hereby claimed under 35 U.S.C. §119(e).
Number | Name | Date | Kind |
---|---|---|---|
4265121 | Cribbs | May 1981 | A |
4340307 | Diamond et al. | Jul 1982 | A |
RE31289 | Moore et al. | Jun 1983 | E |
4510384 | Grimbleby et al. | Apr 1985 | A |
4541272 | Bause | Sep 1985 | A |
4563087 | Bourbin et al. | Jan 1986 | A |
4674844 | Nishioka et al. | Jun 1987 | A |
4718417 | Kittrell et al. | Jan 1988 | A |
4736734 | Matsuura et al. | Apr 1988 | A |
4803992 | Lemelson | Feb 1989 | A |
4854302 | Allred, III | Aug 1989 | A |
4895156 | Schulze | Jan 1990 | A |
4895431 | Tsujiuchi et al. | Jan 1990 | A |
4898175 | Noguchi | Feb 1990 | A |
4923263 | Johnson | May 1990 | A |
4934340 | Ebling et al. | Jun 1990 | A |
4981138 | Deckelbaum et al. | Jan 1991 | A |
5001556 | Nakamura et al. | Mar 1991 | A |
5042494 | Alfano | Aug 1991 | A |
5051823 | Cooper et al. | Sep 1991 | A |
5106387 | Kittrell et al. | Apr 1992 | A |
5120953 | Harris | Jun 1992 | A |
5131398 | Alfano et al. | Jul 1992 | A |
RE34110 | Opie et al. | Oct 1992 | E |
5159446 | Hibino et al. | Oct 1992 | A |
5160837 | Hirane et al. | Nov 1992 | A |
5187572 | Nakamura et al. | Feb 1993 | A |
5200838 | Nudelman et al. | Apr 1993 | A |
5217454 | Khoury | Jun 1993 | A |
5241170 | Field, Jr. et al. | Aug 1993 | A |
5309907 | Fang et al. | May 1994 | A |
5313306 | Kuban et al. | May 1994 | A |
5318024 | Kittrell et al. | Jun 1994 | A |
5377676 | Vari et al. | Jan 1995 | A |
5391352 | Hendrix et al. | Feb 1995 | A |
5402801 | Taylor | Apr 1995 | A |
5408998 | Mersch | Apr 1995 | A |
5414683 | Tani | May 1995 | A |
5417207 | Young et al. | May 1995 | A |
5417210 | Funda et al. | May 1995 | A |
5429616 | Schaffer | Jul 1995 | A |
5434940 | Roff et al. | Jul 1995 | A |
5467104 | Furness, III et al. | Nov 1995 | A |
5467767 | Alfano et al. | Nov 1995 | A |
5517997 | Fontenot | May 1996 | A |
5537213 | Seim et al. | Jul 1996 | A |
5540691 | Elstrom et al. | Jul 1996 | A |
5557444 | Melville et al. | Sep 1996 | A |
5596988 | Markle et al. | Jan 1997 | A |
5601087 | Gunderson et al. | Feb 1997 | A |
5626139 | Szeles et al. | May 1997 | A |
5701132 | Kollin et al. | Dec 1997 | A |
5715825 | Crowley | Feb 1998 | A |
5730134 | Dumoulin et al. | Mar 1998 | A |
5762603 | Thompson | Jun 1998 | A |
5792053 | Skladnev et al. | Aug 1998 | A |
5800478 | Chen et al. | Sep 1998 | A |
5829878 | Weiss et al. | Nov 1998 | A |
5831181 | Majumdar et al. | Nov 1998 | A |
5851181 | Talmor | Dec 1998 | A |
5885293 | McDevitt | Mar 1999 | A |
5928137 | Green | Jul 1999 | A |
5951480 | White et al. | Sep 1999 | A |
5984861 | Crowley | Nov 1999 | A |
5989231 | Snow et al. | Nov 1999 | A |
5994713 | Becker et al. | Nov 1999 | A |
6017312 | Masters | Jan 2000 | A |
6042555 | Kramer et al. | Mar 2000 | A |
6074349 | Crowley | Jun 2000 | A |
6096065 | Crowley | Aug 2000 | A |
6119031 | Crowley | Sep 2000 | A |
6140979 | Gerhard et al. | Oct 2000 | A |
6151167 | Melville | Nov 2000 | A |
6165127 | Crowley | Dec 2000 | A |
6174291 | McMahon et al. | Jan 2001 | B1 |
6174307 | Daniel et al. | Jan 2001 | B1 |
6185443 | Crowley | Feb 2001 | B1 |
6238348 | Crowley et al. | May 2001 | B1 |
6256131 | Wine et al. | Jul 2001 | B1 |
6289229 | Crowley | Sep 2001 | B1 |
6294775 | Seibel et al. | Sep 2001 | B1 |
6324007 | Melville | Nov 2001 | B1 |
6324418 | Crowley et al. | Nov 2001 | B1 |
6331909 | Dunfield | Dec 2001 | B1 |
6498948 | Ozawa et al. | Dec 2002 | B1 |
6622547 | Phan et al. | Sep 2003 | B1 |
7129472 | Okawa et al. | Oct 2006 | B1 |
20010055462 | Seibel | Dec 2001 | A1 |
20020064341 | Fauver et al. | May 2002 | A1 |
Number | Date | Country |
---|---|---|
100 41 878 | Apr 2001 | DE |
2 666 713 | Mar 1992 | FR |
60-217327 | Oct 1985 | JP |
63-040117 | Feb 1988 | JP |
7-289506 | Nov 1995 | JP |
11-298803 | Oct 1999 | JP |
2001-174744 | Jun 2001 | JP |
2001-290100 | Oct 2001 | JP |
9413191 | Jun 1994 | WO |
9822034 | May 1998 | WO |
9822184 | May 1998 | WO |
9822805 | May 1998 | WO |
9916344 | Apr 1999 | WO |
0119235 | Mar 2001 | WO |
Entry |
---|
Hit Lab Research website, “Engineering Study of an Endoscope Design,” Human Interface Lab of University of Washington, <http:// www.hitl.washington.edu/research/endoscope>, 2 pages, dated Apr. 14, 1998, (downloaded Sep. 16, 2001). |
Microvision, Inc. “Imaging Solutions,” <http://web.archive.org/web/20010809170139/http://www.mvis.com/imagingsol.htm>, 6 pages, (downloaded Aug. 9, 2001 archived website), Copyright 2000. |
Microvision 10Q (SEC) filed Aug. 14, 2001, <http://hoovnews.tenkwizard.com/filing.php?repo=tenk&ipage=1474067&doc=1&total=&back=1&g=&attach=on>, 6 pages. |
Seibel, “Engineering Study of a Novel Design for a Scanned, Single Fiber Endoscope,” Investigator Abstracts Biomedical Engineering, <http://www.whitaker.org>, 1 page, (downloaded Sep. 26, 2001). |
Smithwick et al., “Unique Features of the Scanning Single Fiber Endoscope”, Human Interface Technology Laboratory at the University of Washington, 35 pages, Oct. 25, 2001. |
Urey et al., “Scanner Design and Resolution Tradeoffs for Miniature Scanning Displays,” Microvision Inc., <http://www.mvis.com>, 12 pages, (downloaded Oct. 4, 2001), Copyright 2000. |
Urey et al., “Scanner Design and Resolution Tradeoffs for Miniature Scanning Displays,” Microvision Inc., <http://www.web.archive.org/web/20010814233519/www.mvis.com/whitepapers—scannerdesigns.htm, 22 pages, (downloaded Aug. 14, 2001 archived website), Copyright 2000. |
Number | Date | Country | |
---|---|---|---|
20030130562 A1 | Jul 2003 | US |
Number | Date | Country | |
---|---|---|---|
60347391 | Jan 2002 | US |