CN107530034A - Augmented reality pulse oximetry - Google Patents

Abstract

One embodiment relates to a system comprising: a head-mounted member detachably coupled to a user's head; one or more electromagnetic radiation emitters coupled to the head-mounted member and configured to at least one eye of the at least one eye emits light having at least two different wavelengths; one or more electromagnetic radiation detectors coupled to the head-worn member and configured to receive light reflected after encountering at least one blood vessel of the eye; and a controller operatively coupled to the one or more electromagnetic radiation emitters and detectors and configured to cause the one or more electromagnetic radiation emitters to emit light pulses while also causing the one or more electromagnetic radiation The radiation detector detects the level of light absorption associated with the emitted light pulses and produces an output proportional to the blood oxygen saturation level in the blood vessel.

Description

Augmented Reality Pulse Oximetry

Cross References to Related Applications

This application claims priority to US Provisional Application Serial No. 62/133,870 filed March 16, 2015 under 35 U.S.C. §119. The entire content of the above application is incorporated into this application by reference.

technical field

The present disclosure relates to systems and methods for augmented reality using wearable components, and more particularly, to configurations for determining oxygen saturation in a user's blood in the context of an augmented reality system.

Background technique

Modern computing and display technologies have facilitated the development of systems for so-called "virtual reality" or "augmented reality" experiences, in which digitally reproduced images, or parts thereof, are presented to user. Virtual reality or "VR" scenarios generally involve the presentation of digital or virtual image information that is opaque to other actual real-world visual input; augmented reality or "AR" scenarios generally involve the presentation of digital or virtual image information as a visual representation of the user's surroundings. Enhanced visualization of the real world.

For example, referring to FIG. 1 , an augmented reality scene (4) is depicted in which a user of AR technology sees a real-world park-like setting (6) featuring people, trees, buildings in the background, and a physical platform (1120 ). In addition to these items, the user of the AR technology can also perceive that he "sees" the robot statue (1110) standing on the real-world platform (1120), and the flying cartoon-like avatar character (2), by looking at is an anthropomorphism of the bumblebee, even though these elements (2, 1110) do not exist in the real world. As it turns out, the human visual perception system is very complex, and it is extremely challenging to develop a VR or AR technology that facilitates a comfortable, natural-feeling, rich presentation of virtual graphic elements among other virtual or real-world graphic elements . For example, head-mounted AR displays (or head-mounted displays, or smart glasses) are typically at least easily coupled to the user's head, and thus move when the user's head moves. If the user's head movement is detected by the display system, the displayed data can be updated to account for the change in head pose. Certain aspects of suitable AR systems are disclosed, for example, in U.S. Patent Application Serial No. 14/205,126, entitled "Systems and Methods for Augmented and Virtual Reality," which is incorporated herein by reference in its entirety, as well as the and other disclosures of virtual reality systems, such as those developed by Magic Leap, Inc. of Fort Lauderdale, Florida: U.S. Patent Application Serial No. 14/641,376, U.S. Patent Application Serial No. 14/555,585, U.S. Patent Application Serial No. 14 /212,961, U.S. Patent Application Serial No. 14/690,401, U.S. Patent Application Serial No. 13/663,466, U.S. Patent Application Serial No. 13/684,489, and U.S. Patent Application Serial No. 62/298,993, each of which is passed in its entirety by Incorporated herein by reference.

Such AR and VR systems generally include processing capabilities such as controllers or microcontrollers, and power supplies to power the functions of various components, since at least some of the components in a wearable computing system (such as an AR or VR system) operate in close proximity to them The fact of the user's body, so there is an opportunity to use some of these system components to perform certain physiological monitoring tasks with respect to the user. Referring initially to Figures 4A-4C, certain aspects of pulse oximetry are shown. Referring to FIG. 4A , a conventional pulse oximeter device (802) is configured to be temporarily coupled to a user's finger (804), earlobe, or other similar tissue structure, and passed through such tissue structure at different to pulse light at a wavelength of 100 Å while detecting transmission (and thus absorption) at the other side of the tissue structure to provide an output proportional to, or read as, the estimated blood oxygen saturation level Output. For example, such devices are commonly used by high altitude climbers or in medical settings. Figure 4B shows a graph (810) of the absorption spectrum of oxygenated (806) vs. At 660nm, there is a clear difference in the absorption of oxyhemoglobin versus deoxygenated hemoglobin, and the opposite difference at about 940nm in the infrared wavelength range. Pulsed radiation at such wavelengths and detection with pulse oximeters are known to utilize this known difference in absorption for the determination of blood oxygen saturation for a particular user. While pulse oximeters (802) are generally configured to at least partially enclose tissue structures such as fingers (804) or earlobes, certain tabletop style systems, such as that shown in Figure 4C (812), have been proposed to observe Absorption differences in blood vessels of the eye, such as retinal vessels. This configuration (812) may be referred to as a flow oximetry system, and includes the components shown, including a camera (816), zoom lens (822), first (818) and second (820) light emitting diodes ( LED), and one or more beam splitters (814). While it is valuable for certain users (such as high altitude climbers or people with certain cardiovascular or respiratory problems) to be able to easily see their own blood oxygen during their daytime activities or while doing their activities Saturation of the display, but most configurations include inconvenient tissue wrappers, or are not designed or well suited for wearables. The solution proposed here combines the convenience of wearable computing in the form of AR or VR systems with the oxygen saturation monitoring technology of pulse oximetry.

Contents of the invention

One embodiment relates to a system for determining blood oxygen saturation of a user, comprising: a head-mounted member detachably coupled to the user's head; one or more electromagnetic radiation emitters coupled connected to the head-mounted member and configured to emit light having at least two different wavelengths in the visible to infrared spectrum (or in another embodiment, in the invisible to infrared spectrum) in the direction of at least one eye of the user. light; one or more electromagnetic radiation detectors coupled to the head-mounted member and configured to receive light reflected after encountering at least one blood vessel of the user's eye; and a controller operably coupled to the one or more electromagnetic radiation emitters and one or more electromagnetic radiation detectors, and configured such that the one or more electromagnetic radiation emitters emit light pulses while also causing the one or more electromagnetic radiation detectors to detect The light pulse correlates with the level of light absorption and produces an output proportional to the blood oxygen saturation level in the blood vessel. The head mounted member may include eyeglass frames. The spectacle frame may be a binocular spectacle frame. The one or more radiation emitters may include light emitting diodes. The one or more radiation emitters may include a plurality of light emitting diodes configured to emit electromagnetic radiation at two predetermined wavelengths. The plurality of light emitting diodes may be configured to emit electromagnetic radiation at a first wavelength of about 660 nanometers and a second wavelength of about 940 nanometers. The one or more radiation emitters may be configured to sequentially emit electromagnetic radiation at two predetermined wavelengths. One or more radiation emitters may be configured to simultaneously emit electromagnetic radiation at two predetermined wavelengths. The one or more electromagnetic radiation detectors may include devices selected from the group consisting of: photodiodes, photodetectors, and digital camera sensors. The one or more electromagnetic radiation detectors may be positioned and oriented to receive light reflected after encountering at least one blood vessel of the retina of the user's eye. The one or more electromagnetic radiation detectors may be positioned and oriented to receive light reflected after encountering at least one blood vessel of the sclera of the user's eye. The controller may be further configured to cause the plurality of light emitting diodes to emit a cyclic pattern of turning on at a first wavelength, then turning on at a second wavelength, and then turning off at both wavelengths, so that the one or more electromagnetic radiation detectors respectively detect the first wavelength and a second wavelength. The controller may be configured to cause the plurality of light emitting diodes to emit a first wavelength on, then a second wavelength on, then both wavelengths off in a cyclical pattern, in a cyclical pulse pattern approximately thirty times per second. The controller may be configured to calculate a ratio of the first wavelength light measurement to the second wavelength light measurement, and wherein the ratio is converted to a blood oxygen saturation reading via a lookup table based at least in part on Beer-Lambert law. The controller may be configured to operate the one or more electromagnetic radiation emitters and the one or more electromagnetic radiation detectors for use as a head-worn pulse oximeter. The controller can be operably coupled to an optical element that is coupled to the head-worn member and visible to the user such that an output of the controller, which is proportional to blood oxygen saturation in the user's blood vessels, can pass through the optical element seen by the user. the one or more electromagnetic radiation detectors may comprise a digital image sensor comprising a plurality of pixels, wherein the controller is configured to automatically detect a subset of the pixels that are receiving reflected light after encountering at least one blood vessel of the user's eye, And a subset of that pixel is used to produce an output proportional to the blood oxygen saturation level in the blood vessel. The controller may be configured to automatically detect the subset of pixels based at least in part on differences in reflected light brightness among signals associated with the pixels. The controller may be configured to automatically detect a subset of pixels based at least in part on a difference in reflected light absorption among signals associated with the pixels.

Description of drawings

Figure 1 illustrates certain aspects of an augmented reality system presented to a user.

2A-2D illustrate certain aspects of various augmented reality systems for wearable computing applications having a head-mounted component operatively coupled to local and remote processing and data components.

3 illustrates certain aspects of an example of a connection between a wearable augmented or virtual reality system and certain remote processing and/or data storage resources.

4A-4C illustrate various aspects of a conventional pulse oximetry configuration.

Figure 5 illustrates various aspects of a wearable AR/VR system with an integrated pulse oximetry module.

6 illustrates various aspects of techniques for using a wearable AR/VR system with an integrated pulse oximetry module.

Detailed ways

Referring to Figures 2A-2D, some general assembly options are shown. In the section of the detailed description following the discussion of FIGS. 2A-2D , various systems, subsystems, and components are presented that address the goal of providing a high-quality, comfortable-perceived display system for VR and/or AR to humans.

As shown in FIG. 2A , an AR system user ( 60 ) is depicted wearing a head mounted component ( 58 ) featuring a frame ( 64 ) structure coupled to a display system ( 62 ) positioned in front of the user's eyes. In the depicted configuration, speaker (66) is coupled to frame (64) and is positioned adjacent to the user's ear canal (in one embodiment, another speaker, not shown, is positioned adjacent to the user's other ear canal to provide stereo /Shapeable sound control). The display (62) can be operably coupled to a local processing and data module (70), which can be mounted in various configurations, such as fixedly attached to a frame, such as by wired leads or a wireless connection (64), fixedly attached to a helmet or hat (80) as shown in the embodiment of FIG. to the torso (82) of the user (60), or removably attached to the hips (84) of the user (60) in a belt-coupled configuration as shown in the embodiment of FIG. 2D.

The local processing and data module (70) may include a low power processor or controller and digital storage such as flash memory, both of which may be used to assist in the processing, caching and storage of data: (a) from operably coupled Data captured by sensors coupled to the frame (64), such as image capture devices (such as cameras), microphones, inertial measurement units, accelerometers, compasses, GPS units, radios, and/or gyroscopes; and/or (b ) data obtained and/or processed using the remote processing module (72) and/or remote data repository (74), possibly for transmission to the display (62) after such processing or retrieval. The local processing and data module (70) may be operatively coupled (76, 78) to a remote processing module (72) and remote data repository (74), such as by wired or wireless communication links, such that these remote modules (72 , 74) are operatively coupled to each other and serve as available resources to the local processing and data module (70).

In one embodiment, the remote processing module (72) may include one or more relatively powerful processors or controllers configured to analyze and process data and/or image information. In one embodiment, the remote data warehouse (74) may comprise a relatively large-scale digital data storage facility available through the Internet or other network configuration in a "cloud" resource configuration. In one embodiment, all data is stored and all calculations are performed in local processing and data modules, allowing completely autonomous use from any remote module.

Referring now to FIG. 3 , there is schematically shown the coordination between cloud computing assets ( 46 ) and local processing assets, which may, for example, reside in a headset ( 58 ) coupled to the user's head ( 120 ). , and in a local processing and data module (70) coupled to the user's belt (308) (hence component 70 may also be referred to as a "belt bag" 70), as shown in FIG. In one embodiment, such as one or more server systems (110), such as via a wired or wireless network (e.g., wireless for mobility, wired for A cloud (46) asset operatively coupled (115), directly to one or both of the local computing assets (40, 42), such as coupled to the user's head (120) and belt (308) as described above processor and memory configuration. These computing assets of local users may also be operably coupled to each other via wired and/or wireless connection arrangements (44). In one embodiment, in order to maintain the low inertia and small size of the subsystem mounted to the user's head (120), the primary transport between the user and the cloud (46) may be via a subsystem mounted at the belt (308) and the cloud, where the head (12) mounted subsystem is primarily tethered to the belt (308) based on subsystem data using a wireless connection such as an ultra-wideband ("UWB") connection such as is present in personal used in computing peripheral connectivity applications.

Coordinated by effective local and remote processing, and an appropriate display device for the user, such as the user interface or user display system (62) shown in FIG. Portions of the world can be teleported or "passed on" to the user and updated in an efficient manner. In other words, a map of the world may be constantly updated at a storage location that may reside partly on the user's AR system and partly in a cloud resource. A map (also called a "navigable world model") can be a large database that includes raster images, 3-D and 2-D points, parametric information, and other information about the real world. As more and more AR users continue to capture information about their real environment (eg, via cameras, sensors, IMUs, etc.), maps become more accurate and complete.

With the configuration described above, where there is a model of the world that can exist on cloud computing resources and be distributed from there, this world can be "delivered" to one or more users with relatively low bandwidth, better than trying to deliver real-time video data, etc. . The enhanced experience of people standing near the statue (i.e., as shown in Figure 1) can be informed by a cloud-based world model, a subset of which can be passed down to them and their local display device to complete the viewing. A person sitting at a remote display device, which can be as simple as a personal computer sitting on a desk, can effectively download the same portion of information from the cloud and present it on their display. In fact, a person who is actually present in the park near the statue can take a remotely located friend for a walk in the park, joined by the friend through virtual and augmented reality. The system will need to know where the street is, where the trees are where the statue is - but since the information is on the cloud, a friend who joins can download aspects of the scene from the cloud, and then position themselves with augmented reality relative to who is actually in the park start walking.

3-D points can be captured from the environment, and the pose (i.e., vector and/or raw position information relative to the world) of the camera capturing these images or points can be determined such that these points or images can be taken with this pose information" mark" or be associated with it. The pose of the second camera is then determined using the points captured by the second camera. In other words, the second camera may be oriented and/or positioned based on a comparison with the marked image from the first camera. This knowledge can then be used to extract textures, make maps and create a virtual copy of the real world (because then there are two registered cameras around).

Thus, at this baseline level, in one embodiment, 3-D points and 2-D images of generated points can be captured with a person wearable system, and these points and images can be sent to cloud storage and processing resources. They can also be cached locally with embedded pose information (i.e., cache labeled information); thus, the cloud may already have ready (i.e., available cache) labeled 2-D images (i.e., labeled with 3-D pose ) and 3-D points. If the user is looking at something in motion, he may also send other information related to the motion to the cloud (for example, if looking at another person's face, the user can get a texture map of the face and at an optimized frequency upload it, even if the surrounding world is largely static). As mentioned above, more information on object recognizers and navigable world models can be found in U.S. Patent Application Serial No. 14/205,126, entitled "Systems and Methods for Augmented and Virtual Reality," in its entirety The contents of which are incorporated herein by reference, as well as other publications related to augmented and virtual reality systems, such as those developed by Magic Leap, Inc. of Fort Lauderdale, Florida: U.S. Patent Application Serial No. 14/641,376; U.S. Patent Application Serial No. No. 14/555,585; U.S. Patent Application Serial No. 14/212,961; U.S. Patent Application Serial No. 14/690,401; U.S. Patent Application Serial No. 13/663,466; U.S. Patent Application Serial No. 13/684,489; The entire content of each is hereby incorporated by reference.

GPS and other positioning information can be used as input to this process. High-precision positioning of the user's head, totem, gestures, haptic devices, etc. is key to displaying appropriate virtual content to the user.

Referring to FIG. 5 , a top elevation view of a head mounted component ( 58 ) of a wearable computing arrangement is shown, featuring various integrated components for illustration purposes. This configuration has two display elements (62 - binocular - one for each eye), three forward-oriented cameras (124) for viewing and detecting the world around the user, each with an associated field of view (18 , 20, 22); also having a forward-oriented relatively high-resolution picture camera (156) with a field of view (26), one or more inertial measurement units (102), and a camera with an associated field of view (24) A depth sensor (154), such as described in the above disclosure incorporated by reference. Facing the user's eyes (12, 13) and coupled to the head mounted component (58) frame are at least one emitter and at least one detector. The illustrative embodiment shows a redundant configuration with one detector device (830; associated field of view or capture field of 30) for the right eye (13), and one emitter device (834; associated illumination field 826), and one detector device (828; associated field of view or capture field 28) for the left eye (12), and one emitter device (832; associated illumination field 824). These components are shown operatively coupled (836, 838, 840, 842) (eg, by wires) to a controller (844), which is operatively coupled (848) to a power source, such as a battery (846). Preferably, each emitter (832, 834) is configured to controllably emit electromagnetic radiation at two wavelengths, such as about 660nm and about 940nm, for example by an LED, and preferably the illuminated field (824, 826) is directed to irradiate target tissue containing oxygenated and deoxygenated hemoglobin, such as the blood vessels of the sclera of the eye or the retina of the eye; the emitter can be configured to emit both wavelengths simultaneously or sequentially in a controlled pulsed emission cycle. One of the plurality of detectors (828, 830) may comprise a photodiode, photodetector, or digital camera sensor, and is preferably positioned and oriented to receive radiation that has encountered target tissue containing oxygenated and deoxygenated hemoglobin, to Allows detection of absorption and calculation/estimation of blood oxygen saturation. The one or more electromagnetic radiation detectors (828, 830) may comprise a digital image sensor comprising a plurality of pixels, wherein the controller (844) is configured to automatically detect reflected radiation after receiving at least one blood vessel encountering the user's eye A subset of the pixels that emit light, and use a subset of these pixels to produce an output that is proportional to the blood oxygen saturation level in the blood vessel. The controller (844) may be configured to automatically detect a subset of pixels based at least in part on reflected light brightness differences in signals associated with the pixels. The controller (844) may be configured to automatically detect a subset of pixels based at least in part on differences in reflected light absorption among signals associated with the pixels.

Accordingly, a system is presented for determining blood oxygen saturation of a user wearing a wearable computing system, such as one for AR or VR, comprising: a head-mounted member (58) detachably coupled to Attached to the user's head; one or more electromagnetic radiation emitters (832, 834) coupled to the head-mounted member (58) and configured in the direction of at least one of the user's eyes (12, 13) emits light having at least two different wavelengths within the visible to infrared spectrum; one or more electromagnetic radiation detectors (828, 830) coupled to the head-mounted member and configured to receive light reflected behind the at least one blood vessel; and a controller (844) operably coupled to the one or more electromagnetic radiation emitters (832, 834) and the one or more electromagnetic radiation detectors (828, 830) and configured to cause the one or more electromagnetic radiation emitters to emit light pulses while also causing the one or more electromagnetic radiation detectors to detect the level of light absorption associated with the emitted light pulses and to generate blood oxygen in blood vessels The saturation level is proportional to the output. The head mounted member (58) may include eyeglass frames. The eyeglass frames may be binocular eyeglass frames; alternative embodiments may be monocular. One or more radiation emitters (832, 834) may include light emitting diodes. The one or more radiation emitters (832, 834) may include a plurality of light emitting diodes configured to emit electromagnetic radiation at two predetermined wavelengths. The plurality of light emitting diodes may be configured to emit electromagnetic radiation at a first wavelength of about 660 nanometers and a second wavelength of about 940 nanometers. One or more radiation emitters (832, 834) may be configured to sequentially emit electromagnetic radiation at two predetermined wavelengths. One or more radiation emitters (832, 834) may be configured to simultaneously emit electromagnetic radiation at two predetermined wavelengths. The one or more electromagnetic radiation detectors (828, 830) may include devices selected from the group consisting of: photodiodes, photodetectors, and digital camera sensors. One or more electromagnetic radiation detectors (828, 830) may be positioned and oriented to receive light reflected after encountering at least one blood vessel of the retina of the user's eye (12, 13). One or more electromagnetic radiation detectors (828, 830) may be positioned and oriented to receive light reflected after encountering at least one blood vessel of the sclera of the user's eye. The controller (844) can also be configured to cause the plurality of light emitting diodes to emit a cyclic pattern of a first wavelength on, a second wavelength on, and both wavelengths off, such that the one or more electromagnetic radiation detectors respectively detect the first and a second wavelength. The controller (844) can be configured to cause the plurality of light emitting diodes to emit a cyclic pattern of a first wavelength on, then a second wavelength on, then both wavelengths off, in a cyclic pulse pattern approximately thirty times per second. The controller (844) may be configured to calculate a ratio of the first wavelength light measurement to the second wavelength light measurement, and wherein the ratio is converted to a blood oxygen saturation reading via a lookup table based at least in part on Lambert-Beer's law. Controller (844) may be configured to operate one or more electromagnetic radiation emitters (832, 834) and one or more electromagnetic radiation detectors (828, 830) for use as a head-worn pulse oximeter. The controller (844) can be operably coupled to the optical element (62) that is coupled to the head mounted member (58) and seen by the user such that the blood oxygen saturation in the user's blood vessels The output of the proportional controller (844) can be seen by the user through the optics (62).

6 illustrates various aspects of techniques or methods for using a wearable AR/VR system with an integrated pulse oximetry module. Referring to FIG. 6, a head-mounted member or frame (850) detachably coupled to the user's head may be provided, and the component configuration may be operably coupled to the head-mounted member, having: one or more electromagnetic a radiation emitter coupled to the head-mounted member and configured to emit light having light of at least two different wavelengths; one or more electromagnetic radiation detectors coupled to the head-worn member and configured to receive light reflected after encountering at least one blood vessel of the user's eye; and a controller, It is operatively coupled to one or more electromagnetic radiation emitters and one or more electromagnetic radiation detectors, and is configured to cause the one or more electromagnetic radiation emitters to emit light pulses while also causing one or more electromagnetic The radiation detector detects the level of light absorption associated with the emitted light pulse and produces an output proportional to the blood oxygen saturation level in the blood vessel (852). The controller may be operable to cause the one or more radiation emitters to emit electromagnetic radiation at two predetermined wavelengths, such as a first wavelength of about 660 nanometers and a second wavelength of about 940 nanometers, be turned on at the first wavelength, and then turned on at the second wavelength , then a cyclical pattern of two wavelengths off (eg, about thirty times per second) such that the one or more electromagnetic radiation detectors detect the first and second wavelengths, respectively (854). The controller is operable to calculate a ratio of the first wavelength light measurement to the second wavelength light measurement, and wherein the ratio is converted to a blood oxygen saturation reading based at least in part on Lambert-Beer's law via a lookup table (856).

In one embodiment, the bulk of the overall eye-based pulse oximetry activity is performed using software operated by the controller (844) to enable localization of blood vessels (i.e., within the sclera, retina, or other eye/vascular anatomy) ) is performed using digital image processing (such as by color, grayscale, and/or intensity threshold analysis using various filters), and can also be performed using pattern and/or shape recognition; the software and controller can be configured to Uses the intensity of the center of the target vessel and the intensity of the surrounding tissue to determine contrast/optical density; along with identifying the target vessel or other structure, emission/detection and processing of detected data (which may include image processing) can be used to determine contrast ; the density ratio (contrast) can then be calculated using the controller (844), and the blood oxygen saturation is calculated from the density ratio as described above. The vessel optical density ("OD") at each of two or more emission wavelengths can be calculated using the formula OD _vessel = -log ₁₀ ^(Iv/Ir) , where OD _vessel is the optical density of the vessel; _Iv is the vessel intensity; and _Ir is the intensity of the surrounding retinal tissue. Blood oxygen saturation (also called "SO2") can be calculated as a linear ratio of vessel optical density at _two wavelengths (OD ratio or "ODR" ₎ such that SO2 = ODR = OD _{first wavelength} / OD _{second wavelength} .

In one embodiment, wavelengths of about 570 nm (sensitive to deoxyhemoglobin) and about 600 nm (sensitive to oxyhemoglobin) may be used in retinal vessel oximetry such that SO ₂ =ODR=OD _600nm /OD _550nm ; This formula does not take into account the adjustment of the ratio by the calibration factor.

Various exemplary embodiments of the invention are described herein. Reference is made to these examples in a non-limiting sense. These examples are provided to illustrate the broader applicable aspects of the invention. Various changes may be made and equivalents may be substituted for the invention as described without departing from the true spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation, material, composition of matter, process, process act or step to the objective, spirit or scope of the invention. Further, each individual variation described and illustrated herein has independent components and characteristics, which can be readily compared with The features of any one of several other embodiments are separated or combined. All such modifications are intended to be within the scope of the claims associated with this disclosure.

The present invention includes methods that can be performed using a subject device. The method may include the act of providing such suitable means. Such provisioning may be performed by end users. In other words, the act of "providing" requires only obtaining, accessing, processing, locating, setting, activating, powering on, or other action by the end user to provide the necessary means in the method. The methods described herein may be performed in any order of events described which is logically possible and in the order of events described.

Exemplary aspects of the invention have been described above, along with details regarding material selection and fabrication. Other details of the present invention can be understood in conjunction with the above-referenced patents and publications and what is generally known or understood by those skilled in the art. The same holds true with respect to method-based aspects of the invention with respect to additional acts as commonly or logically employed.

Furthermore, while the invention has been described with reference to several examples optionally including various features, the invention is not limited to that described or represented as contemplated for every variation of the invention. Various changes may be made to the invention as described, and equivalents (whether stated herein or not included for the sake of brevity) may be substituted without departing from the true spirit and scope of the invention. In addition, where a range of values is provided, it is understood that each intervening value between the upper and lower limits of that range, and or any other intervening value in that stated range, is encompassed within the invention.

Furthermore, it is contemplated that any optional feature of the described inventive variations may be stated and claimed independently or in combination with any one or more of the features described herein. References to singular items include that there may be plural occurrences of the same item. More specifically, as used herein and in the dependent claims, the singular forms "a," "said," and "the" include plural referents unless specifically stated otherwise. In other words, in the above description as well as in the claims related to this disclosure, the use of the article allows for "at least one" of the subject item. It should also be noted that such claims could be drafted to exclude any optional elements. Accordingly, this statement is intended to be used as an antecedent basis for the use of such exclusive terms as "solely," "only," etc., or a "negative" limitation, in conjunction with the expression of claim elements.

In the absence of such an exclusive term, the term "comprising" in a claim related to the present disclosure shall allow the inclusion of any other element, regardless of whether a given number of elements is recited in such claim, or Adding features may be seen as altering the properties of elements recited in the claims. Unless specifically defined herein, all technical and scientific terms used herein should be given the best possible commonly understood meaning while maintaining claim validity.

The invention is not limited to the examples provided and/or this specification, but only by the scope of the language of the claims to which this disclosure relates.

Claims (19)

1. A system for determining blood oxygen saturation of a user, comprising: a. a head-mounted member detachably coupled to the user's head; b. one or more electromagnetic radiation emitters coupled to the head mounted member and configured to emit light having at least two different wavelengths within the visible to infrared spectrum in the direction of at least one eye of the user ; c. one or more electromagnetic radiation detectors coupled to the head mounted member and configured to receive light reflected after encountering at least one blood vessel of the eye of the user; and d. a controller operatively coupled to the one or more electromagnetic radiation emitters and the one or more electromagnetic radiation detectors and configured to cause the one or more electromagnetic radiation emitters to emit light pulse while also causing the one or more electromagnetic radiation detectors to detect the level of light absorption associated with the emitted light pulse and produce an output proportional to blood oxygen saturation in the blood vessel. 2. The system of claim 1, wherein the head-mounted member comprises an eyeglass frame. 3. The system of claim 2, wherein the eyeglass frame is a binocular eyeglass frame. 4. The system of claim 1, wherein the one or more radiation emitters comprise light emitting diodes. 5. The system of claim 4, wherein the one or more radiation emitters comprise a plurality of light emitting diodes configured to emit electromagnetic radiation at two predetermined wavelengths. 6. The system of claim 5, wherein the plurality of light emitting diodes are configured to emit electromagnetic radiation at a first wavelength of about 660 nanometers and a second wavelength of about 940 nanometers. 7. The system of claim 5, wherein the one or more radiation emitters are configured to sequentially emit electromagnetic radiation at the two predetermined wavelengths. 8. The system of claim 5, wherein the one or more radiation emitters are configured to simultaneously emit electromagnetic radiation at the two predetermined wavelengths. 9. The system of claim 1, wherein the one or more electromagnetic radiation detectors comprise devices selected from the group consisting of: photodiodes, photodetectors, and digital camera sensors. 10. The system of claim 1, wherein the one or more electromagnetic radiation detectors are positioned and oriented to receive light reflected after encountering at least one blood vessel of the retina of the user's eye . 11. The system of claim 1 , wherein the one or more electromagnetic radiation detectors are positioned and oriented to receive light reflected after encountering at least one blood vessel of the sclera of the user's eye . 12. The system of claim 6, wherein the controller is further configured to cause the plurality of LEDs to emit a cyclic pattern of a first wavelength on, then a second wavelength on, then both wavelengths off , such that the one or more electromagnetic radiation detectors respectively detect the first wavelength and the second wavelength. 13. The system of claim 12, wherein the controller is configured to cause the plurality of light emitting diodes to emit a first wavelength on, then a second wavelength on, then both wavelengths off in a cyclical pattern, at approximately Cyclic pulse mode thirty times per second. 14. The system of claim 12, wherein the controller is configured to calculate a ratio of the first wavelength light measurement to the second wavelength light measurement, and wherein the ratio is based at least in part on Lambert-Beer's law via a lookup table Converts to SpO2 readings. 15. The system of claim 14, wherein the controller is configured to operate the one or more electromagnetic radiation emitters and the one or more electromagnetic radiation detectors for use as a head-worn pulse oximeter . 16. The system of claim 15, wherein the controller is operatively coupled to an optical element coupled to the head mounted member and visible to the user such that the The output of the controller proportional to the blood oxygen saturation level in the blood vessels of the user can be seen by the user through the optical element. 17. The system of claim 9, wherein the one or more electromagnetic radiation detectors comprise a digital image sensor comprising a plurality of pixels, and wherein the controller is configured to automatically detect that the a subset of pixels of light reflected behind at least one blood vessel of the user's eye, and using the subset of pixels to generate the output proportional to blood oxygen saturation levels in the blood vessel. 18. The system of claim 17, wherein the controller is configured to automatically detect the subset of pixels based at least in part on differences in reflected light brightness among signals associated with the pixels. 19. The system of claim 17, wherein the controller is configured to automatically detect the subset of pixels based at least in part on differences in reflected light absorption among signals associated with the pixels.