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  Hand held device and methods for examining a patient's retinaHand held device and methods for examining a patient's retina description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20080002152, Hand held device and methods for examining a patient's retina. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is a continuation of prior U.S. patent application Ser. No. 11/053,491, titled "HAND HELD DEVICE AND METHODS FOR EXAMINING A PATIENT'S RETINA" filed Feb. 7, 2005, which application is hereby incorporated herein by reference. FIELD OF THE INVENTION [0002] This invention relates, in general, to methods and devices for performing an examination of the eye, and more particularly, for performing an examination of the retina of a patient's eye. BACKGROUND OF THE INVENTION [0003] Many conventional retinal eye examinations involve the use of eye drops which are given to a patient to force the patient's iris open (dilates the pupils). These drops are known as mydriatic eye drops. After the patient's pupils are dilated, the eye doctor then examines the patient's retina, also known as the "fundus," with a conventional ophthalmoscope, which typically uses white light. Once a conventional eye exam is completed, the patient's pupils remain dilated for possibly hours, which may be very inconvenient for the patient and may prevent the patient from being able to drive, work, etc. [0004] Viewing the retina and optic nerve is a basic part of both general medical exams (as performed by family practitioners, pediatricians, internists and other medical professionals) and eye exams (as performed by ophthalmologists and optometrists). As part of a general exam, the retina is the only place in the body where the practitioner can view blood vessels directly. Diseases that affect blood vessels, such as diabetes mellitus and hypertension, among others, can be diagnosed on the basis of changes in retinal blood vessels. Studies have shown that the blood vessel changes in the eye in these diseases correlate well with similar changes in other parts of the body, such as the kidney. Therefore the amount to which the vascular changes associated with these diseases has progressed can also be ascertained. [0005] The optic nerve, which is actually a part of the brain, can also be visualized. Increased intracranial pressure (e.g., as caused by brain tumors) can often be diagnosed by seeing the resultant swelling of the optic nerve. [0006] From the standpoint of the eye professional, specific important potentially blinding diseases, such diabetic retinopathy, glaucoma, and macular degeneration, among others, can both be diagnosed and followed by viewing the retina and optic nerve. [0007] An instrument used to view the retina and optic nerve is called an ophthalmoscope. It may be either battery operated or powered from a transformer. In either case, only visible light is available for viewing the patient. Even with the use of filters, the light is uncomfortable to the patient, sometimes to the point of making the examination difficult or impossible. Opacities to visible light located in the lens of the eye (e.g., cataract) or in the vitreous (e.g., blood) also limit the ability to see the retina and optic nerve, sometimes totally precluding such examination. [0008] In order to better study, document, share and record the changes seen in the retina and optic nerve, photographs of the back of the eye (called fundus photos) are frequently taken. The standard camera for doing this is a large table mounted instrument which generally uses photographic film (although digital variants have recently become available) and flash photography. Some smaller variants have been developed, but still require cables hooked to large power supplies, resulting in cumbersome units. [0009] The large camera units generally may require the services of a professional photographer to operate, and the units may be priced in the range from $35,000 to $100,000, both of which factors limit their availability. The table mountings can make them inaccessible to wheel-chair patients, unless special table extensions are available. The cameras are rarely available for bed patients, in some instances. Also, such cameras are difficult to move from office to office, except by van [0010] As recognized by the present inventors, what is needed is a hand held device and method for examining a patient's retina without the need for mydriatic eye drops, so that retinal examinations can be performed quickly, accurately, and comfortably without dilation of the patient's pupils. [0011] It is against this background that various embodiments of the present invention were developed. SUMMARY OF THE INVENTION [0012] In light of the above and according to one broad aspect of one embodiment of the invention, disclosed herein is a hand held device for examining a patient's retina. In one example, the device generates visible or non-visible light beams or light rays having desired spectral content that can be used, after polarization, for illuminating the patient's retina during the examination. The illuminating beams may include infrared (IR) or visible light. IR light can be used to perform the examination through the patient's undilated pupil, without the need for mydriatic drops, and the images received and processed by the hand held device can be real-time, dynamic video images of the retina. Visible light can be used for short time periods (i.e., approximately 0.1 to 0.008 seconds or other time periods) to image the retina for static or still images. Further, the hand held device may generate light selectively having two or more spectral ranges, and alternatively couple light of different spectral ranges into the optical path of the device. For instance, the illuminating beam section can provide IR light to view the retina in real-time (i.e., dynamic real time video images), then be controllably switched to provide a pulse of visible light to take a still image (i.e., a high resolution static image), then be controllably switched to again provide IR light. Hence, a hand held device according to an embodiment of the present invention can provide both video and high quality still photographic capabilities. Furthermore, in another example, the illuminating beam section can provide IR light to view the retina in real-time (i.e., dynamic real time video images), then be controllably switched to provide light with an appropriate exitation wavelength to excite fluorescein dye or other conventional dyes to perform dye studies of the retina. [0013] In one embodiment, the illuminating beams generated by the device are polarized to generate polarized light beam(s) that are used to illuminate the patient's retina. A specific polarization state is imparted on the light directed towards the patient's eye. In one example, the polarized light beam travels towards the patient's retina along an optical path that is disposed at an angle (such as 90 degrees) relative to the generated illuminated light beam. [0014] At the patient's eye, a portion of the polarized beam is then partially reflected by the patient's cornea. This corneal reflection (which is polarized) travels back in the direction of the device. Another portion of the polarized beam enters the eye through the pupil, illuminates the patient's retina, and this generates a reflected retinal image (generally de-polarized) which travels back in the direction of the device. [0015] In one example, the device receives the retinal image as well as the polarized corneal reflections. The device transmits (i.e., does not reflect or block) certain portions of the retinal image, defined by their polarization states, on through to an image capture detector (such as a CCD or CMOS detector or capture device, or other digital or non-digital image capture device). The image capture portion of the device may include optics to process the retinal image. [0016] As to the polarized corneal reflections, in one example, the device receives the polarized corneal reflections and does not materially transmit these polarized corneal reflections to the image detector (i.e., the corneal reflections are diverted, reflected, or otherwise extinguished). Hence, the image detector receives retinal images having certain states of depolarized light but does not materially receive the polarized corneal reflected light. [0017] According to another broad aspect of one embodiment of the present invention, disclosed herein is a hand held device for examining a retina through a pupil. In one example, the hand held device may include a light source generating light (visible or non-visible); a first lens refracting the light to form a refracted beam; a first polarizer receiving the refracted beam and forming a linear polarized beam; a second polarizer for reflecting linearly polarized light, the second polarizer receiving the linear polarized beam and reflecting the linear polarized beam; and a second lens refracting the linear polarized beam from the second polarizer, the second lens converging the linear polarized beam for passage through the pupil to illuminate the retina. This illumination of the retina can produce a retinal image that is received and processed by the hand held device. Further, the device can be used to examine the patient's retina through an undilated pupil, without the need for mydriatic drops. [0018] In one example, the light generated by the light source includes infrared (IR) light, and the light source may include a first lamp in series with an infrared (IR) filter to generate the IR light. In another example, the light generated by the light source includes visible light. [0019] The light source may include two or more discrete light sources providing different spectral ranges of illumination, for example, a first lamp in series with an infrared (IR) bandpass filter to generate IR light, a second lamp in series with an visible light bandpass filter to generate visible light, wherein when the first lamp is on, the second lamp is off. A simple electronic switch may be used to provide power to the first lamp and not the second, and then to provide power to the second lamp and not the first. In this manner, the device can switch between two different spectral ranges of illumination, without the need for moving parts. [0020] In another example, the device may also include a reflector reflecting the light to form a reflected converging beam for coupling into the first lens. The device may also include a variable diaphragm located between the light source and the first lens for controlling the intensity of the light. The device may also include a beam splitter positioned between the first lens and the first polarizer, the beam splitter receiving the refracted beam, the beam splitter reflecting the refracted beam to the first polarizer. Continue reading about Hand held device and methods for examining a patient's retina... Full patent description for Hand held device and methods for examining a patient's retina Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Hand held device and methods for examining a patient's retina patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Hand held device and methods for examining a patient's retina or other areas of interest. ### Previous Patent Application: Ophthalmologic apparatus Next Patent Application: Optotype presenting apparatus Industry Class: Optics: eye examining, vision testing and correcting ### FreshPatents.com Support Thank you for viewing the Hand held device and methods for examining a patient's retina patent info. IP-related news and info Results in 0.28312 seconds Other interesting Feshpatents.com categories: Daimler Chrysler , DirecTV , Exxonmobil Chemical Company , Goodyear , Intel , Kyocera Wireless , |
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