Abstract: According to various embodiments, a medical sensor assembly may include compressible light barriers configured to prevent undesired light from being detected. The compressible light barriers may protrude from the surface of the sensor. However, when applied to the tissue, the compressible light barriers may be compressed to the point of being substantially flush with the tissue.

Abstract: A multisystem sensor is disclosed that includes a first sensor subsystem and a second sensor subsystem. The multisystem sensor includes a sensor body having both sensor subsystems. The first sensor subsystem may monitor a first physiological characteristic and the second sensor subsystem may monitor a second physiological characteristic. The sensor body may include an isolating portion configured to isolate the first sensor subsystem and the second sensor subsystem. The sensor body and/or isolating portion may include refractive components and/or filters to prevent interference between sensor subsystems.

Abstract: An apparatus for integrally processing a plurality of biologic signals includes a first signal processing module and a second signal processing module. The first processing module generates a signal for operating a sensing module, which includes a plurality of sensor groups which measures the plurality of biologic signals, and which processes a biologic signal provided from the plurality of sensor groups based on a control signal. The second signal processing module authenticates a sensor group from among the plurality of sensor groups, generates the control signal according to a result of the authentication while automatically setting a processing condition, processes the biologic signal provided from the first signal processing module according to the processing condition and outputs a result of processing the biologic signal.

Abstract: Methods, apparatus, and systems for detecting hemozoin and diagnosing malaria infection are disclosed.

Abstract: The present disclosure relates generally to medical devices and, more particularly, to optical medical sensors used for sensing physiological characteristics of a patient. In one embodiment, a system includes a physiological sensor having a photodetector array with a plurality of photodetectors configured to receive light from patient tissue. The physiological sensor also includes a multiplexor configured select and output a signal from the photodetector array. The physiological sensor may also include a signal analyzer configured to determine the signal quality for each of the output signals of the photodetector array and select an output signal, based on the signal quality determination, for the calculation of a physiological parameter of the patient. In another embodiment, a system includes a pulse oximetry sensor having a multiplexed array of photodetectors configured to receive light from patient tissue.

Abstract: Optical sensor devices, image processing devices, methods and computer readable code computer-readable storage media for detecting biophysical parameters, chemical concentrations, chemical saturations and blood count. In some embodiments, the image processing device receives a live still or video electronic image. Exemplary physiological parameters include but are not limited to a pulse rate, blood pressure, glucose, stroke volume of internal or external tissue (e.g. skin). A biophysical or physiological property is not limited to a cardiovascular or liver or the kidneys or to a cardiovascular disorder or to a pulmonary disorder. Exemplary chemical concentrations or saturation includes but not limited to a pH level, a glucose level, a urea nitrogen level, a CO2 concentration or saturation, or a oxygen concentration or saturation. In some embodiments the parameters are detected from a food or a beverage such as an alcohol, a dairy product, wine, a baked good, a fruit or a vegetable.

Abstract: A sensor holder to be applied on an appendage of a subject is disclosed herein. The sensor holder includes a substrate with at least a first location for a first sensor component, the substrate surrounding a hollow for receiving the appendage along a longitudinal axis of the hollow. The substrate is gradually thickening when drawing away at least a predetermined distance from the at least first location for the first sensor component along a perpendicular direction of the substrate in relation to the longitudinal axis of the hollow.

Abstract: An object information acquiring apparatus is used. This apparatus comprises: a light source configured to emit pulsed light of a plurality of wavelengths; a wavelength controller configured to switch the wavelength; a probe configured to receive an acoustic wave generated and propagated in an object subjected to the pulsed light emitted onto the object; a scan controller configured to move the probe within a predetermined scanning range; and an information processor configured to acquire information about the object by using a plurality of electric signals corresponding to the wavelengths of the pulsed light output from the probe at each reception position in the scanning area. The wavelength controller switches the wavelength of the pulsed light before the probe scans the entire scanning area while receiving at each reception position an acoustic wave corresponding to at least one of the wavelengths of the pulsed light.

Abstract: In vivo devices, systems and methods for in vivo immunoassay include inserting into a patient's body lumen an in vivo diagnostic device comprising a housing. The housing of the device comprises a chamber, and a chromatography strip for immunoassay of a body lumen substance. The housing may further comprise a casing for the chromatography strip. The casing may comprise a first opening to allow entrance of in vivo liquids into the casing and a second opening into the chamber. The housing may further comprise a sensor to sense a property of the chromatography strip. Following insertion of the device into the patient's body, a sample is collected and the immunoassay is performed in vivo in areas of pathological lesions for a predetermined period of time. An in vivo image may be acquired or other data such as colorimetric or intensity data may be obtained from the chromatography strip.

Abstract: Multi-wavelength photon density wave medical systems, methods, and devices are provided. In one embodiment, a multi-wavelength system may include a sensor, a sensor cable, and a patient monitor. The sensor may have an emitter output and a detector input configured to pass a multi-wavelength photon density wave input signal into a patient and receive a resulting multi-wavelength photon density wave output signal. The sensor cable may couple to the sensor using two optical cables for transmitting and receiving the multi-wavelength photon density wave signals. The patient monitor may couple to the sensor cable and generate several time-division multiplexed single-wavelength input signals by modulating one or more light sources at a frequency sufficient to produce resolvable photon density waves.

Abstract: A monitoring device configured to be attached to the ear of a person includes a base, an earbud housing extending outwardly from the base that is configured to be positioned within an ear of a subject, and a cover surrounding the earbud housing. The base includes a speaker, an optical emitter, and an optical detector. The cover includes light transmissive material that is in optical communication with the optical emitter and the optical detector and serves as a light guide to deliver light from the optical emitter into the ear canal of the subject wearing the device at one or more predetermined locations and to collect light external to the earbud housing and deliver the collected light to the optical detector.

Abstract: According to various embodiments, a hat-based or headband sensor assembly may include thin or flexible optical sensing components, such as optical fibers or ultra thin emitters or detectors. In embodiments, the sensor assembly may be a hat-based sensor that includes a gripping region, for example on the inside of the hat band, to help secure the hat to a patient's head.

Abstract: Embodiments of the present disclosure include an optical probe capable of communicating identification information to a patient monitor in addition to signals indicative of intensities of light after attenuation by body tissue. The identification information may indicate operating wavelengths of light sources, indicate a type of probe, such as, for example, that the probe is an adult probe, a pediatric probe, a neonatal probe, a disposable probe, a reusable probe, or the like. The information could also be utilized for security purposes, such as, for example, to ensure that the probe is configured properly for the oximeter, to indicate that the probe is from an authorized supplier, or the like.

Abstract: A multiple wavelength optical sensor has an emitter configured to radiate light having a plurality of wavelengths into a tissue site. The emitter comprises a plurality of LEDs configured in an array and connected within an electrical grid. A detector is configured to receive the light after absorption by pulsatile blood flow within the tissue site. The detector generates a sensor signal capable of being processed by a patient monitor so as to derive oxygen saturation, carboxyhemoglobin, methemoglobin and total hemoglobin.

Abstract: An orthopedic system to monitor a parameter related to the muscular-skeletal system is disclosed. The orthopedic system includes electronic circuitry, a sensor, and a remote system to monitor and measure. The sensor is configured to measure color or turbidity. The electronic circuitry is coupled to and interfaces with the sensor. The electronic circuit includes a transmitter to transmit measurement data from the sensor to the remote system. The orthopedic system is configured to monitor color or turbidity of a fluid in proximity to the muscular-skeletal system. The orthopedic system can transmit a signal when a predetermined color is detected or when the turbidity of the fluid exceeds a predetermined value. Alternatively, the remote system includes a processor and software configured to analyze the measurement data from the sensor and transmit a signal when a predetermined color is detected or when the turbidity of the fluid exceeds a predetermined value.

Abstract: Systems, devices, and methods are described for providing a monitor or treatment device configured to, for example, detect hemozoin, as well as to monitor or treat a malarial infection.

Abstract: A sensor that may be used to detect the presence, amount, and/or concentration of an analyte in a medium within an animal. The sensor may include a sensor housing, an indicator element embedded within and/or covering at least a portion of the sensor housing, and a membrane over the indicator element. The membrane may reduce indicator element deterioration by preventing immune cells, such as white blood cells, from contacting the indicator element, substantially prevent transmission of light of at least a specified wavelength or range of wavelengths through the membrane, and/or permit the analyte to pass through to the indicator element. The membrane may be an opaque diffusion membrane. The sensor may include a foil. The foil may block light and/or reduce indicator element deterioration. The membrane may reduce oxidation of the indicator element.

Abstract: A sensor that may be used to detect the presence, amount, and/or concentration of an analyte in a medium within an animal. The sensor may include a sensor housing, an indicator element embedded within and/or covering at least a portion of the sensor housing, and a membrane over the indicator element. The membrane may reduce indicator element deterioration by preventing immune cells, such as white blood cells, from contacting the indicator element, substantially prevent transmission of light of at least a specified wavelength or range of wavelengths through the membrane, and/or permit the analyte to pass through to the indicator element. The membrane may be an opaque diffusion membrane. The sensor may include a foil. The foil may block light and/or reduce indicator element deterioration. The membrane may reduce oxidation of the indicator element.

Abstract: Disclosed are methods and devices comprising an elongated probe for the in vivo detection of meconium in amniotic fluid held in an amniotic sac based on detecting the presence of Zinc-coproporphyrin I (ZnCP). ZnCP is excited at approximately 405 nm and emits characteristic fluorescence, centered at about 580 nm and less intensely at 630 nm.

Abstract: An imaging probe for a biological sample includes an OCT probe and an ultrasound probe combined with the OCT probe in an integral probe package capable of providing by a single scanning operation images from the OCT probe and ultrasound probe to simultaneously provide integrated optical coherence tomography (OCT) and ultrasound imaging of the same biological sample. A method to provide high resolution imaging of biomedical tissue includes the steps of finding an area of interest using the guidance of ultrasound imaging, and obtaining an OCT image and once the area of interest is identified where the combination of the two imaging modalities yields high resolution OCT and deep penetration depth ultrasound imaging.

Abstract: A device includes a pliable membrane, a sensor module and a communication module. The pliable membrane includes a semi-rigid structural member. The membrane is configured to conform to a tissue surface. The structural member is configured to retain the membrane in a particular shape corresponding to the tissue surface. The sensor module is coupled to the membrane. The sensor module is configured to generate an electrical signal corresponding to a physiological parameter associated with the tissue surface. The communication module is coupled to the membrane. The communication module is configured to receive the electrical signal and wirelessly communicate data corresponding to the electrical signal with a remote device.

Abstract: A NIRS sensor assembly includes a light source, a light detector, a first insulating layer, an EMI shielding layer, and a second insulating layer. The first insulating layer covers an exposed portion of the light detector. An optically transparent portion of the first insulating layer is aligned with an active area of the light detector. The EMI shielding layer covers the first insulating layer. An optically transparent portion of the EMI shielding layer is aligned with the active area of the light detector. The second insulating layer covers the EMI shielding layer and the first insulating layer. An optically transparent portion of the second insulating layer is aligned with the active area of the at least one light detector.

Abstract: One or more physiological conditions of a patient can be observed by obtaining a photoplethysmograph (“PPG”) signal from the patient and by only lightly filtering that signal. The light filtering of the PPG may be such as to only remove (for example) high frequency noise from that signal, while leaving in the signal most or all frequency components that are due to physiological events in the patient. In this way, such physiological events can be observed via a visual display of the lightly filtered PPG signal and/or via other signal processing of the lightly filtered PPG signal to automatically extract certain physiological parameters or characteristics from that signal.

Abstract: Provided herein is a stabilized oxygen transport matrix that includes a reversible oxygen binding protein, such as hemoglobin, immobilized throughout the stabilized oxygen transport matrix. The stabilized oxygen transport matrix is used to transport oxygen and can be used as an oxygen transport region and a reaction region of an analyte sensor, such as an implantable glucose sensor. The reversible binding protein can also function as an oxygen probe within the analyte sensor.

Abstract: A method and apparatus for dating a body sample, for example a sample of body fluid involves taking a series of spectroscopic measurements of the sample, each measurement in the series including at least two predetermined positions in the spectrum. The positions have spectral characteristics corresponding to two or more predetermined substances present in the sample that have a time varying relationship with each other. The measurements in the series are spaced in time. A concentration of each of the substances present in the sample is then determined from each of the spectroscopic measurements at each point in time. Next, a ratio of the concentrations of the two predetermined substances at each point in time is determined and then the ratios of the concentrations of the two predetermined substances over time are analyzed to estimate when the concentrations of the two substances were at a limit of their concentrations, thereby providing an indication of the age of the sample.

Abstract: To make the peak value of the driving current of light source smaller than the conventional one and to make the peak value of the light receiving level of light-sensitive elements smaller than the conventional one in order to save power consumption of the device and to improve the precision of measurement, codes of which the bits of the Hadamard codes are shifted by the same bit for each code series having the same bit cycle, or codes of which the bits of a PN code are shifted are used as different codes.

Abstract: The present invention is a Miniature Vein Enhancer that includes a Miniature Projection Head. The Miniature Projection Head may be operated in one of three modes, AFM, DBM, and RTM. The Miniature Projection Head of the present invention projects an image of the veins of a patient, which aids the practitioner in pinpointing a vein for an intravenous drip, blood test, and the like. The Miniature projection head may have a cavity for a power source or it may have a power source located in a body portion of the Miniature Vein Enhancer. The Miniature Vein Enhancer may be attached to one of several improved needle protectors, or the Miniature Vein Enhancer may be attached to a body similar to a flashlight for hand held use. The Miniature Vein Enhancer of the present invention may also be attached to a magnifying glass, a flat panel display, and the like.

Abstract: The present disclosure relates to an interface for a noninvasive glucose sensor that comprises a front-end adapted to receive an input signals from optical detectors and provide corresponding digital signals. In one embodiment, the front-end comprises switched capacitor circuits that are capable of handling multiple streams signals from the optical detectors. In another embodiment, the front-end comprises transimpedance amplifiers that are capable of handling multiple streams of input signals. In this embodiment, the transimpedance amplifier may be configured based on its own characteristics, such as its impedance, the impedance of the photodiodes to which it is coupled, and the number of photodiodes to which it is coupled.

Abstract: An apparatus includes a source and a detector. The source is operable to transmit light. The detector is operable to receive at least a portion of the light transmitted by the source. The source and the detector can be positioned on a nail of a digit such that the light enters the nail through an entrance region. The light further exits the nail through an exit region. The entrance region is defined by a lateral portion of the nail. The light is directed to interact with at least one analyte.

Abstract: An image of a portion to be observed is captured while first light beams are applied thereto. Thereby, a first image signal of a first frame is obtained. The first light beams are in a wavelength range in which an absorption coefficient varies in accordance with a change in oxygen saturation of hemoglobin in blood. An image of the portion to be observed is captured while second light beams are applied thereto. Thereby, a second image signal of a second frame is obtained. The second light beams have a broadband wavelength range. Blood volume and oxygen saturation are obtained from the first and second image signals. A blood volume image representing information on the blood volume in pseudo-color and an oxygen saturation image representing information on the oxygen saturation in pseudo-color are generated. The blood volume image is displayed simultaneously with the oxygen saturation image on a display device.

Abstract: A device for in vivo analysis includes: a reaction chamber to store a detecting reagent able to react with a sample collected in vivo; and optionally a labeled-substance chamber to store a labeled substance able to bind to at least a portion of a compound resulting from a reaction of the detecting reagent and the sample. The in-vivo imaging device, typically an autonomous capsule, may have a housing, the housing comprising a window; an illumination source located within the housing to illuminate a body lumen through the window; an imager to receive light reflected from the body lumen through the window; and a transmitter to transmit image data to a receiving system. The window is coated with liposomes containing a marker such that the imager may acquire images which include the marking.

Abstract: Non-invasive apparatus and method for determining and monitoring glucose concentrations in human subjects. Glucose level is estimated through the effect of glucose on biological cells with glucose dependencies, e.g., red blood cells. The invention is based on the interaction of such cells with oscillating electric field gradients. The response of biological cells depends on factors including shape, size, and electrical charge distribution. The field gradient causes the cells to undergo characteristic motion which is detected by light beam scattering. The autocorrelation of the scattered light is computed, and the Fourier transform (FT) is performed to produce a characteristic velocity spectrum in which the peaks are characteristic of the cell “bio-electrical” states. The glucose level is estimated through measurements of changes of FT with changes in glucose levels after calibration with standard glucose methods.

Abstract: An apparatus and method for noninvasive determination of analyte properties of human tissue by quantitative infrared spectroscopy to clinically relevant levels of precision and accuracy. The system includes subsystems optimized to contend with the complexities of the tissue spectrum, high signal-to-noise ratio and photometric accuracy requirements, tissue sampling errors, calibration maintenance problems, and calibration transfer problems. The subsystems can include an illumination/modulation subsystem, a tissue sampling subsystem, a data acquisition subsystem, a computing subsystem, and a calibration subsystem. The invention can provide analyte property determination and identity determination or verification from the same spectroscopic information, making unauthorized use or misleading results less likely than in systems that use separate analyte and identity determinations. The invention can be used to control and monitor individuals accessing controlled environments.

Abstract: A patient monitor has multiple sensors adapted to attach to tissue sites of a living subject. The sensors generate sensor signals that are responsive to at least two wavelengths of optical radiation after attenuation by pulsatile blood within the tissue sites.

Abstract: Support structures for positioning sensors on a physiologic tunnel for measuring physical, chemical and biological parameters of the body and to produce an action according to the measured value of the parameters. The support structure includes a sensor fitted on the support structures using a special geometry for acquiring continuous and undisturbed data on the physiology of the body. Signals are transmitted to a remote station by wireless transmission such as by electromagnetic waves, radio waves, infrared, sound and the like or by being reported locally by audio or visual transmission. The physical and chemical parameters include brain function, metabolic function, hydrodynamic function, hydration status, levels of chemical compounds in the blood, and the like. The support structure includes patches, clips, eyeglasses, head mounted gear and the like, containing passive or active sensors positioned at the end of the tunnel with sensing systems positioned on and accessing a physiologic tunnel.

Abstract: A method and an apparatus measure blood oxygenation in a subject. A light source is activated to cause a first emission at a first wavelength and a second emission at a second wavelength. A detector detects a composite signal indicative of an attenuation of the first and second wavelengths by tissue of a patient. The composite signal is demodulated into a first intensity signal and a second intensity signal. Blood oxygenation in the subject is determined from the first and second intensity signals.

Abstract: Confidence in a physiological parameter is measured from physiological data responsive to the intensity of multiple wavelengths of optical radiation after tissue attenuation. The physiological parameter is estimated based upon the physiological data. Reference data clusters are stored according to known values of the physiological parameter. At least one of the data clusters is selected according to the estimated physiological parameter. The confidence measure is determined from a comparison of the selected data clusters and the physiological data.

Abstract: An apparatus for electrically and mechanically coupling a connection portion of a sensor assembly with a connection portion of an interface cable is provided. The apparatus includes a frame having an EMI shielding material. The frame defines a first port operable to engage the connection portion of the sensor assembly and a second port operable to engage the connection portion of the interface cable. The frame includes attachment features operable to mechanically secure the connection portion of the sensor assembly and the connection portion of the interface cable relative to the frame. The frame is configured to provide a Faraday Cage around substantially all of the connection portion of the sensor assembly and the connection portion of the interface cable when the connection portions are in coupled configuration.

Abstract: A system for measuring a physiological parameter of blood in a patient is presented. The system includes a transmission module configured to emit a plurality of photon density waves into tissue of the patient from a plurality of modulated light sources. The system also includes a receiver module configured to detect characteristics of the plurality of photon density waves. The system also includes a processing module configured to identify characteristics of a pulsatile perturbation of the tissue based on the characteristics of the plurality of photon density waves, and identify a value of the physiological parameter based on at least the characteristics of the pulsatile perturbation of the tissue and the characteristics of the plurality of photon density waves.

Abstract: A process is provided for analyzing a skin in any of a number of biochemical or immunological tests for an analyte which involves applying to a skin surface on a patient a reagent which selectively binds to the analyte to form an analyte-reagent complex; subjecting the skin surface on the patient to a treatment which develops a color correlating to an amount of analyte in the specimen; measuring a hue angle of the color developed on the skin surface of the patient by measuring a reflectance over a range of visible light spectrum at a plurality of intervals in wavelength of the visible light spectrum to obtain a measurement; and correlating the measurement of the hue angle to determine a concentration of the analyte.

Abstract: Aspects of the present disclosure include a sensor emitter including a reflective cavity for re-directing light to a tissue site. By reflecting light towards the tissue site, the amount of light reaching the tissue site is increased. The increased light can improve parameter measurements taken by a non-invasive physiological sensor by producing a stronger and/or cleaner signal. In an embodiment, the reflective cavity is formed on one or more lead frames of the sensor emitter, wherein the lead frames are capable of transmitting electrical signals to emitting elements coupled to the lead frames. Aspects of the present disclosure also include a sensor component configured to protect connection points of wires to conductive leads on the sensor components by inhibiting flex or bending at the connection points. Connection points can protrude along edges of the sensor component. Aspects of the present disclosure also include techniques and processes for producing low-profile sensors.

Abstract: The current invention is directed towards a rapid, reproducible test for the fungal virulence factors and associated affected compounds so that patients at risk for autism, cerebral palsy and other human diseases can be quickly identified, treated and possibly prevented. This includes a multitude of test protocols for both the mycotoxin gliotoxin and its relationship with glutathione- and relates the two molecules by a novel paradigm known as the Glutathione-Gliotoxin Index-(GGI) or Disease-Disorder Susceptibility Index-D/DSI, which indicates the Autism Susceptibility Index-(ASI). One testing device and protocol includes a cellular phone application with modification to test for susceptibility to autism and other disease states.

Abstract: A disposable portion of an optical probe is usable to determine at least one physiological parameter. The disposable portion comprises a bandage including adhesive on at least a portion of at least one face thereof. The bandage comprises a first receptacle at a first position. The first receptacle is configured to receive and removably engage a probe emitter. The bandage comprises a second receptacle at a second position. The second position is spaced from the first position. The second receptacle is configured to receive and removably engage a probe detector. The first receptacle at the first position is positioned generally opposite the second receptacle at the second position when the bandage is positioned on an appendage of a patient for sensing a physiological parameter of the patient.

Abstract: A method and medical device for detecting signals that detects emitted light scattered by a volume of tissue delivered along a first pathway at a plurality of wavelengths to generate corresponding first detected light intensity output signals, detects emitted light scattered by the volume of tissue delivered along a second pathway different from the first pathway at a plurality of wavelengths to generate corresponding second detected light intensity output signals, determines whether a difference between the emitted light detected along the first pathway and the emitted light detected along the second pathway is greater than a predetermined threshold, and alters sensing by the device in response to the determining whether a difference is greater than the predetermined threshold.

Abstract: A system that monitors water displacement in tissue during patient therapy includes a generator supplying electrosurgical energy to tissue, a spectrometer operably coupled to the generator, and a processor communicating with the generator and with the spectrometer having a light source for exposing tissue to light and a light sensor. The light sensor is configured to sense changes in light through tissue in response to tissue treatment and communicate the changes to the processor to determine tissue hydration levels and motility. A plurality of optical fibers may be configured in an array to communicate light between the generator and tissue. An optical temperature monitor may communicate with the processor and be coupled to an optical fiber. The optical fibers may have an optic fiber distance between adjacent optical fibers. The system may be incorporated within an electrosurgical pencil or a forceps. A corresponding method of detecting hydration is also disclosed.

Abstract: Embodiments of the present disclosure relate to sensors for applying pressure to a patient's tissue. According to certain embodiments, the sensors may include one or more deformable elements that hold the optical components of the sensor against the tissue with an appropriate amount of pressure. In additional embodiments, such sensors may include a rigid one-piece sensor body that incorporates a deformable element to facilitate fine-fitting of the sensor against the tissue.

Abstract: A sensor for the detection or measurement of carbohydrate analyte (such as glucose) in fluid comprises components of a competitive binding assay the readout of which is a detectable or measurable optical signal (such as FRET assay) retained by a material that permits diffusion of analyte but not the assay components, the assay components comprising: an animal lectin; and an analyte analogue capable of competing with analyte for binding to the lectin.

Abstract: A method of making up the skin or the lips, the method including measuring at least one optical characteristic at least one location of the skin or the lips; and automatically forming on the skin or lips a deposit that has an optical characteristic that varies and that corresponds substantially at said location, to the measured optical characteristic.

Abstract: A monitoring device configured to be attached to the ear of a person includes a base, an earbud housing extending outwardly from the base that is configured to be positioned within an ear of a subject, and a cover surrounding the earbud housing. The base includes a speaker, an optical emitter, and an optical detector. The cover includes light transmissive material that is in optical communication with the optical emitter and the optical detector and serves as a light guide to deliver light from the optical emitter into the ear canal of the subject wearing the device at one or more predetermined locations and to collect light external to the earbud housing and deliver the collected light to the optical detector.

Abstract: A secondary-emitter sensor position indicator has primary emitters that transmit light having primary wavelengths and at least one secondary emitter that transmits light having at least one secondary wavelength. A detector outputs a sensor signal in response to received light. An attachment assembly, in a sensor-on condition, positions the emitters and detector relative to a tissue site so that the sensor signal is substantially responsive to the primary wavelength light after attenuation by pulsatile blood flow within the tissue site and is negligibly responsive to the secondary wavelength light. The attachment assembly, in a sensor out-of-position condition, positions the secondary emitter relative to the tissue site so that the sensor signal is at least partially responsive to the secondary wavelength.