Abstract: Disclosed examples include heart rate monitor systems and methods to estimate a patient heart rate or rate of another pulsed signal, in which rate hypotheses or states, are identified for a current time window according to digital sample values of the pulsed signal for a current sample time window, and a rate change value is computed for potential rate transitions between states of the current and previous time windows. Transition pair branch metric values are computed as a function of the rate change value and a frequency domain amplitude of the corresponding rate hypothesis for the current time window, and the pulsed signal rate estimate is determined according to a maximum path metric computed according to the branch metric value and a corresponding path metric value for the previous time window.

Abstract: An apparatus for monitoring an oxygen saturation level of a wearer includes a first body portion, a second body portion, and a connection member. The first body portion contains a processor, a memory operably coupled to the processor, at least one light-emitting diode, and at least one optical sensor configured to detect, during operation, a reflected portion of light emitted from the at least one light-emitting diode. The second body portion includes a grommet, and the connection member is mechanically coupled to each of the first body portion and the second body portion. The memory stores instructions to cause the processor to cause light to be emitted from the at least one light-emitting diode when the apparatus is positioned on an ear of a wearer and during operation of the apparatus, and to calculate a blood oxygen saturation level of the wearer based on the reflected portion of light.

Abstract: Provided is an information processing apparatus that includes an acquisition section that acquires a multi-spectral image consistent with an imaging result of a subject by using light divided into a plurality of wavelength bands and an extraction section that extracts a feature value by performing a computational process on the multi-spectral image on the basis of coefficients appropriate to absorption spectral properties of one or more pigments.

Abstract: Systems, methods, and devices of a health device network may include: a non-invasive glucometer that non-invasively measures analyte levels; an invasive glucometer communicatively coupled directly to the non-invasive glucometer; a cloud-based server communicatively coupled to the non-invasive glucometer or the invasive glucometer; a user device communicatively coupled to the cloud-based server; and/or a user interface that displays the invasive glucose measurement, the non-invasive glucose measurement, a data batch, and/or processed data to the user. The non-invasive glucometer and/or the invasive glucometer may aggregate an invasive glucose measurement and a non-invasive glucose measurement into the data batch.

Abstract: A measurement engine of a wearable electronic device may compensate for wavelength variations of light emitted as part of blood-oxygen saturation measurements. In some cases, determining an estimated blood-oxygen saturation value is based at least partially on temperature data that may be used to compensate for temperature-based wavelength variations of the emitted light, drive current data that may be used to compensate for drive-current-based wavelength variations of the emitted light, and/or calibration information that may be used to compensate for manufacturing variability across different light emitters. In various embodiments, the measurement engine may use temperature data, the drive current data, and/or calibration information in a variety of ways to determine estimated blood-oxygen saturation values, including using lookup tables or calibration curves, applying functions, and the like.

Abstract: Systems, methods, and devices of a health device network may include: a non-invasive glucometer that non-invasively measures analyte levels; an invasive glucometer communicatively coupled directly to the non-invasive glucometer; a cloud-based server communicatively coupled to the non-invasive glucometer or the invasive glucometer; a user device communicatively coupled to the cloud-based server; and/or a user interface that displays the invasive glucose measurement, the non-invasive glucose measurement, a data batch, and/or processed data to the user. The non-invasive glucometer and/or the invasive glucometer may aggregate an invasive glucose measurement and a non-invasive glucose measurement into the data batch.

Abstract: A wearable computing device includes one or more processors, memory and a physiological metric sensor system, including a light source configured to direct light into tissue of a user wearing the wearable computing device, a light detector implemented a distance away from the light source and configured to detect light from the light source that reflects back from the user, and a light-blocking portion implemented between the light source and the light detector. The wearable computing device may further include an audio port directed towards an ear canal of the user and control circuitry configured to activate the light source during a period of time and generate a light detector signal indicating an amount of light detected by the light detector during the period of time.

Abstract: A non-invasive method and apparatus utilizing a single wavelength (800 nm, isobestic) for the instantaneous, reflective, non-pulsatile spatially resolved reflectance system, apparatus and mathematics that allows for the correct determination of critical photo-optical parameters in vivo. Transcutaneous blood constituent (analyte or drug level) measurements can be determined in real-time. The “closed-form” nature of the mathematics with inclusion of other wavelengths (660 nm and 1300 nm) and a non-invasive transmissive array allows for immediate calculation and real-time display of Hematocrit, Hemoglobin, fractional tissue blood volume (Xb), Hematocrit-Independent Oxygen Saturation, fractional tissue water content (Xw) and other pertinent blood/plasma values in a variety of handheld or other like devices.

Abstract: A apparatus for obtaining an individualized unit spectrum includes: a spectrum obtainer configured to obtain a first biological spectrum from a subject at a first measurement time, and obtain a second biological spectrum from the subject at a second measurement time; and a processor configured to extract the individualized unit spectrum from the first biological spectrum and the second biological spectrum, based on a predetermined unit spectrum of a target component.

Abstract: An ITE hearing instrumentality, for use in an ear canal, that includes a housing, a receiver located within the housing, an earpiece on the housing that is configured to mount the housing within the ear canal, and at least one biometric sensor on the earpiece.

Abstract: Some embodiments described herein relate to an apparatus including a light source configured to transmit an excitation optical signal to an implanted sensor and a detector configured to detect an analyte-dependent optical signal emitted from an implanted sensor. The apparatus can include a lens configured to focus at least a portion of the analyte-dependent optical signal onto the detector.

Abstract: A system for monitoring an oil and gas process includes a data acquisition circuit structured to interpret a plurality of detection values corresponding to input received from a detection package which includes at least one of a plurality of input sensors each operatively coupled to at least one of a plurality of components of an industrial production process; a data analysis circuit structured to analyze a subset of the plurality of detection values to determine a status parameter; and an analysis response circuit structured to adjust the detection package in response to the status parameter, wherein the plurality of available sensors have at least one distinct sensing parameter selected from the sensing parameters consisting of: input ranges, sensitivity values, locations, reliability values, duty cycle values, sensor types, and maintenance requirements.

Abstract: The present disclosure relates to an oral cavity based device, system and toolkit which identifies the human or animal through the unique demarcations oral cavity. These unique demarcations are described as “oralsprint” identifiers (IDs) used to both identify and measure saliva-based biologics and other biometrics through one or more electronic sensors and related technologies for humans and animals to herein as ORAL AND SALIVA BASED EQUINE ID DRUG MONITORING.

Abstract: An optical apparatus having an illumination module with a carrier, which has at least one light-transmissive region, for example. The illumination module has a plurality of light sources, which are arranged on the carrier.

Abstract: A system includes a monitor configured to be coupled to multiple sensors over time to monitor one or more physiological characteristics of one or more patients, and including an information collection system configured to store in a database unique sensor identifying information and information related to plural uses of the same sensor.

Abstract: An illuminated needle device for performing a heart valve repair includes an outer member and an inner member. The outer member includes a body that has a proximal end and a distal end. The body of the outer member defines a lumen therethrough and the distal end of the body includes a needle. The inner member is slidably disposed within the lumen of the outer member. The inner member includes a distal end that has a radiation emitting element. The illuminated needle device is characterized by the outer and inner members together forming a flexible, elongate shaft, and the inner member being configured to emit radiation from the radiation emitting element from a location proximate to the distal end of the outer member.

Abstract: The invention provides a physiological parameter sensing system (50) and method in which physiological information indicative of at least one physiological parameter is derived. The approach of the invention is based on constructing multiple pulse signals from different weighted combinations of at least two detection signals, derived from detected electromagnetic radiation directed onto or through a subjects skin region. The weightings are based on different of a set of various blood volume pulse vectors. A quality indication value is derived for each generated pulse signal, where this is based on a derived relationship between an obtained heart rate signal for the patient and the pulse signal. The blood volume pulse vector resulting in the pulse signal having the highest quality indicator value and/or from the derived pulse signal itself is used to derive the physiological parameter information.

Abstract: A monitoring device configured to be attached to a subject includes a photoplethysmography (PPG) sensor configured to detect/measure physiological information from the subject, and a processor configured to process the physiological information to detect subject stress, and to determine an origin of the subject stress. The processor can determine the origin of the subject stress by increasing a sampling rate of the PPG sensor to collect higher acuity physiological information. The processor also can determine the origin of the subject stress by processing data from the PPG sensor to determine whether the subject is likely to have atrial fibrillation. In response to determining that the subject is likely to have atrial fibrillation, the processor can increase a frequency of pulsing of an optical emitter of the PPG sensor and/or increase a sampling rate of the PPG sensor to collect higher acuity data for diagnosing that atrial fibrillation is truly occurring.

Abstract: Provided is an optical sensor, including a light source configured to emit light; a photodetector array comprising a plurality of photodetectors positioned at different distances from the light source, each photodetector being configured to detect an optical signal returning from an object irradiated by the light emitted by the light source, and to measure a light intensity of the detected optical signal; and a processor configured to determine a correlation coefficient between variables based on the measured light intensity, and to determine a quality of the optical signal based on the determined correlation coefficient, an optical characteristic of the object being determined by selectively using the optical signal of which the quality is an acceptable level or higher.

Abstract: A personalized bio-information correcting apparatus includes a communication interface configured to acquire original bio-information value data of a user, and a processor configured to obtain a personalized bio-information guideline, based on a personalized physiological model, identify whether at least one value among the acquired original bio-information value data is an outlier, based on the obtained personalized bio-information guideline, and based on the at least one value among the acquired original bio-information value data being identified to be the outlier, obtain final bio-information value data by correcting the at least one value among the acquired original bio-information value data.

Abstract: A personal hand-held monitor (PHHM) comprising a signal acquisition device for acquiring signals which can be used to derive a measurement of a parameter related to the health of the user, wherein the signal acquisition device comprises a blood photosensor having one or more photo-emitters for transmitting light to a body part of a user, one or more photo-detectors for detecting light transmitted through or scattered by the body part and two or more optical cells, at least one of which contains an analyte to be detected or which mimics the absorption spectrum of the analyte to be detected, through which the light that has been or will be transmitted through or scattered by the body part passes before it reaches the or each photo-detector, wherein the processor of the PHHM is adapted to process the signals received from the or each photo-detector to calculate the difference in intensity of light which has passed through the or each analyte cell and light which has passed through the or each non-analyte cell an

Abstract: An ambulatory medical device and a method of communication between medical devices are disclosed. In one embodiment, the medical device includes a module for communication with at least a second medical device wherein the module for communication is adapted to be activated by a value of a physiological parameter of an animal. In one embodiment, the method of the present invention involves a first medical device and at least a second medical device wherein the communication between said medical devices is activated by a value of a physiological parameter of an animal.

Abstract: A holder (40) for holding a stack (10) of coverslips (11) or specimen slides (11) has a bottom (20) having at least one side wall (21a, 21b, 22a, 22b) connected thereto, wherein an inner side of the bottom (20) is embodied for placement of the stack (10) of coverslips (11) or specimen slides (11) and carrying that stack (10), and an outer side of the bottom (20) and/or an outer side of the at least one side wall is configured to receive an identification label, such as an RFID (30), and the holder includes such the identification label, such as an RFID (30).

Abstract: A system is provided for scanning organs in a human body, preferably a human's cardiovascular system more preferably the heart and other arteries. The system includes an extracorporeal opto-acoustic scanning device for scanning from outside of the body and optionally in correlation to inside optic imaging Both comprise a laser or other opto acoustic light and a transducer. The laser being arranged to emit laser pulses towards and/or into the organ system and the transducer being arranged to detect acoustic waves received back from the organ system for imaging the scanned tissue.

Abstract: A monitoring device configured to be attached to a subject includes a photoplethysmography (PPG) sensor configured to measure physiological information from the subject, and at least one processor configured to process signals from the PPG sensor to determine heart rate and RR-interval (RRi) for the subject, and to determine a heart rate pattern for the subject over a period of time. The at least one processor is configured to change a sampling frequency of the PPG sensor for determining RRi in response to the determined heart rate pattern. The at least one processor is configured to reduce the sampling frequency of the PPG sensor in response to determining a pattern of heart rate below a threshold.

Abstract: A headset includes a housing defining an audio cavity, a speaker located within the audio cavity, and first and second sensor modules within the housing in spaced-apart, angled relationship to each other. The housing includes an aperture through which sound from the speaker can pass, and the first and second sensor modules are on opposing sides of a direction from the speaker to the aperture. The first sensor module is configured to direct electromagnetic radiation at a first target region of an ear of a person wearing the headset and to detect a first energy response signal therefrom that is associated with one or more physiological metrics of the subject, and the second sensor module is configured to direct electromagnetic radiation at a second target region of the ear and to detect a second energy response signal therefrom that is associated with the one or more physiological metrics.

Abstract: An apparatus adapted to be worn at or near at least one ear of a subject includes a battery, a reflective pulse oximeter, a motion sensor, an analog-to-digital convertor configured to convert analog signals from the reflective pulse oximeter and the motion sensor into digitized information, a speaker, a digital memory device configured to store at least one algorithm for signal processing, a transceiver, and a signal processor. The signal processor is configured to process data from the reflective pulse oximeter to monitor cardiopulmonary functioning of the subject, process data from the motion sensor to monitor head and body motion, execute the at least one algorithm for assessing a health state of a subject, poll the reflective pulse oximeter and the motion sensor at certain time intervals to extend life of the battery, and process digital audio information into analog sounds to be presented to the subject via the speaker.

Abstract: A spectrophotometric apparatus for determining optical parameters in a scattering medium based on the measurement of attenuation of light propagating through said medium by diffusion. To eliminate the detrimental effect of light being guided in an intermediate optical layer between a surface of the medium and a contact surface of the apparatus, either a multitude of optical barriers may be formed in the contact surface or the angular range over which light is emitted or received by the apparatus may be limited by appropriate means. With both of these alternative approaches, light propagation in the intermediate layer can be suppressed, leading to increased measurement accuracy. This is particularly beneficial for building an oximeter with improved precision. Further aspects include features for improving the applicability of the apparatus on curved surfaces such as the strongly curved skulls of neonates.

Abstract: An embodiment of the present disclosure seeks to select characteristics of incoming intensity data that cause comparisons of selected characteristics to produce defined probe off space having reduced crossover with defined probe on space. Once defined, the present disclosure compares characteristics of incoming intensity data with the now defined probe off space, and in some embodiments, defined probe on space, to determine whether a probe off condition exists. When a processor determines a probe off condition exists, the processor may output or trigger an output signal that audibly and/or visually indicates to a user that the optical sensor should be adjusted for a proper application to a measurement site.

Abstract: Disclosed herein are portable diagnostic measurement devices for determining at least one analysis parameter of a bodily fluid, in particular for determining an analyte concentration in a bodily fluid as can occur in blood glucose determinations. Also disclosed are analysis systems including the measurement device and at least one disposable test element. The test element can be designed as a carrier strip and can contact a receiving surface of the measurement device at least partially in a flat manner, where the receiving surface is arranged on a narrow side of the housing of the measurement device.

Abstract: A point-of-care medical testing system integrated with a patient monitor is disclosed. The system may include a microfluidic cartridge configured to receive a blood sample and generate a sensory signal dependent on a concentration of a biomarker in the blood sample. A cartridge reading assembly receives the microfluidic cartridge. The cartridge reading assembly includes a processing unit and a memory coupled with the processing unit. The memory stores executable instructions to cause the processing unit to receive the sensory signal, correlate the received sensory signal with the concentration of the biomarker in the blood sample, and produce an output representative of the concentration of the biomarker in the blood sample. The cartridge reading assembly is coupled to the patient monitor and configured to send the output to the patient monitor.

Abstract: A technique for realizing energy saving. According to a biological information acquisition device, light emitting power per unit area of one light emitting element emitting light when first biological information is acquired is weaker than light emitting power per unit area of one light emitting element emitting light when second biological information is acquired.

Abstract: Described herein are embodiments of systems and methods that utilize temperature measurements taken with head-mounted sensors as well as images of a user's face to detect fever and/or intoxication. One embodiment of a system to detect fever includes a first head-mounted temperature sensor that measures skin temperature (Tskin) at a first region on a user's head, a second head-mounted temperature sensor that measures a temperature of the environment (Tenv), and a computer. The computer receives images of a second region on the user's face, captured by a camera sensitive to wavelengths below 1050 nanometer, and calculates, based on the images, values indicative of hemoglobin concentrations at three or more regions on the user's face. The computer can then detect whether the user has a fever based on Tskin, Tenv and the values.

Abstract: The present invention relates to a device for measuring a physiological parameter of a human limb such as peripheral capillary oxygen saturation. The device comprises a body comprising a first body part and a second body part, which are movable relative to each other to define an opening with an adjustable size for receiving the limb therein, and a physiological sensor for interacting with the limb received in the opening, the sensor being attached to the body, wherein the first and second body parts are slidable or twistable relative to each other while at least partially engaging or intersecting each other, or wherein the first and second body parts are configured to form a clip having an L-shaped end section for at least partially enclosing the limb received in the opening, in order to adjust the size of the opening.

Abstract: Embodiments herein relate to chemical sensors for detecting a physiological analyte. In an embodiment, an implantable medical device including a chemical sensor for detecting an ion concentration in a bodily fluid is provided. The chemical sensor can include a sensing element having an outer barrier layer forming a top, a bottom, and opposed sides, where the top of the outer barrier layer can be created from a polymeric matrix permeable to sodium ions, potassium ions, and hydronium ions. An active agent can be disposed within the top of the outer barrier layer, the active agent having anti-inflammatory effects. The chemical sensor can include an optical excitation assembly configured to illuminate the sensing element. The chemical sensor can also include an optical detection assembly configured to receive light from the sensing element. Other embodiments are also included herein.

Abstract: A sensor module includes a light emitter that emits light beams including near-infrared light beams towards a subject; a light receiver that receives light beams having passed through the subject; and a controller that estimates biological information based on signals output from the light receiver. The light emitter includes a plurality of light emitting elements that emit near-infrared light beams having central wavelengths different from each other. The light emitter produces sets of light emissions by causing the plurality of light emitting elements to sequentially and intermittently emit the near-infrared light beams. In given two consecutive sets of light emissions produced by the light emitter, a second non-light-emission period of time T4 is longer than a first non-light-emission period of time T2. The controller estimates the biological information in a processing period of time T41 that is set in correspondence with the second non-light-emission period of time T4.

Abstract: A wearable diagnostic device worn on a user's body that can provide various types of health-related information to the user is described. The wearable diagnostic device can provide real-time, non-invasive, accurate, and continuous data regarding a user's heart rate, hemoglobin level, body temperature, oxygen level, glucose level, and blood pressure. In some implementations, the wearable diagnostic device may also provide electrocardiogram (EKG) data or detection of Parkinson's symptoms, such as the involuntary movement of a user's hand. A user may configure the wearable diagnostic device to provide information on one, multiple, or all of the health-related information noted above.

Abstract: A system includes an enclosure having a processor and a memory coupled to the processor. The enclosure includes a display coupled to the processor where the display is visible from an exterior of the enclosure; and a battery within the enclosure coupled to the processor and the display. The enclosure includes a probe tip coupled to an exterior of the enclosure. The probe tip includes first, second, and third sensor openings. A first distance between the first and second sensor openings is different than a second distance between the first and third sensor openings. The enclosure includes code stored in the memory where the code is executable by the processor, and includes code to receive first data associated with the first and second sensor openings, code to receive second data associated with the first and second sensor openings, and code to perform SRS using the first and the second data.

Abstract: An apparatus comprising: a light detector; a light source, laterally offset from the light detector by a first lateral offset; optics configured to receive light emitted by the light source and output the received light, wherein a majority of the light output is directed towards an offset region laterally offset from the light detector by at least a second lateral offset different from the first lateral offset.

Abstract: A system and method to measure blood oxygenation levels and total hemoglobin on individually selected blood vessels, to provide a representation of the subject condition and of tissue perfusion that may be used for diagnosing specific tissue conditions. Reflection spectra from individual blood vessels or a collection of vessels are measured by using wide-field imaging for selecting target vessels and a narrow-field confocal detection system to enable measuring local blood oxygenation and hemoglobin. Optical fibers may be used to illuminate the target vessel and to detect light diffusively reflected therefrom. The reflection spectra may be analyzed in a spectrometer to extract the ratio of the deoxy- to oxyhemoglobin and to determine their absolute concentration for computing total hemoglobin levels. An alternative implementation uses image processing on camera images of a blood vessel, generated at an isosbestic wavelength of the deoxy- and oxyhemoglobin, and optionally also at neighboring wavelengths.

Abstract: A liquid surface detecting apparatus including: a retaining section that retains liquid as sample or reagent; a light emitter that emits light toward the liquid retained in the retaining section; an image capturing device that captures an image of the liquid retained in the retaining section; and a detecting device that detects a level of a liquid surface of the liquid retained in the retaining section based on the image of the liquid captured by the image capturing device, wherein the image capturing device is provided at a position such that the light, emitted by the light emitter and reflected by the liquid surface of the liquid, directly enters the image capturing device.

Abstract: Non-linear methods for quantitative elemental analysis and mineral classification using laser-induced breakdown spectroscopy are disclosed. According to one embodiment, a method, comprises calculating concentrations of elements in a sample using a laser-induced breakdown spectroscopy (LIBS) instrument. The LIBS instrument implements a kernel partial-least-squares regression (KPLSR) analysis. The method further comprises displaying the concentrations of the elements according to the KPLSR analysis.

Abstract: A substance concentration monitoring method includes inserting a temperature probe noninvasively into a volume of a body in which a concentration of a substance is to be measured. An internal temperature of the volume is measured and an internal temperature signal is produced. An incident first near infrared beam in a first wavelength band is directed from a light source into a portion of the volume, the first wavelength band including a wavelength at which an absorption peak exists in a NIR absorption spectrum of the substance. An incident second NIR beam in a second wavelength band is directed from the light source into the portion of the volume, the substance exhibiting no absorption or negligible absorption in the second wavelength band. Substance concentration is calculated based on values corresponding to the internal temperature signal, a first and second initial power signal, and a first and second material absorption signal.

Abstract: An integrated system for determining a hemostasis and oxygen transport parameter of a blood sample, such as blood, is disclosed. The system includes a measurement system, such as an ultrasonic sensor, configured to determine data characterizing the blood sample. For example, the data could be displacement of the blood sample in response to ultrasonic pulses. An integrated aspect of the system may be a common sensor, sample portion or data for fast and efficient determination of both parameters. The parameters can also be used to correct or improve measured parameters. For example, physiological adjustments may be applied to the hemostatic parameters using a HCT measurement. Also, physical adjustments may be applied, such as through calibration using a speed or attenuation of the sound pulse through or by the blood sample. These parameters may be displayed on a GUI to guide treatment.

Abstract: A method and system for communicating estimated blood loss parameters of a patient to a user, the method comprising: receiving data representative of an image, of a fluid receiver; automatically detecting a region within the image associated with a volume of fluid received at the fluid receiver, the volume of fluid including a blood component; calculating an estimated amount of the blood component present in the volume of fluid based upon a color parameter represented in the region, and determining a bias error associated with the estimated amount of the blood component; updating an analysis of an aggregate amount of the blood component and an aggregate bias error associated with blood loss of the patient, based upon the estimated amount of the blood component and the bias error; and providing information from the analysis of the aggregate amount of the blood component and the aggregate bias error, to the user.

Abstract: A method for predicting a blood glucose level using a near-Infrared (NIR) spectrometer is provided. The method may include obtaining a feature set from an NIR glucose spectra; and predicting glucose values from the feature set based on a binary classification of the NIR glucose spectra and an in-class prediction of glucose using Machine Learning Regression.

Abstract: A monitor system configured to selectively attach a light emitter assembly and a light receiver assembly to a finger. The monitor system comprising the light emitter assembly, the light receiver assembly, an upper assembly a lower assembly, and an intermediate support. The monitor system comprises an attached portion and a detached portion. The attached portion is configured to attach to a fingernail of the finger. The detached portion is configured to selectively and releasably attach to the attached portion. The monitor system is configured to emit one or more emitted lights through the finger between the light emitter assembly and the light receiver assembly.

Abstract: A solution containing a target molecule and a reference molecule is illuminated to obtain Raman signals. An optical metasurface is used as a diffractive optical element to split the Raman signal from the target molecule and the Raman signal from the reference molecule. The target and reference Raman signals can be detected at different locations with different photodetectors, and the target molecule concentration in the solution is determined by comparing the target and reference Raman signals.

Abstract: The present disclosure generally relates to wearable devices and methods for measuring a photoplethysmographic signal. The wearable devices and methods may include a force sensor that provides input used for motion-noise filtering to obtain improved PPG signals. Feedback from the force sensor may also be used to indicate whether the amount of pressure exerted by the device should be adjusted, or whether the device should be switched to a locked state.

Abstract: A method for calibration of a photoplethysmographic device including the steps of providing a fluid circuit (305) for blood or other liquid, a pump mechanism (310) to generate pulsatile flow of blood through the fluid circuit, a sample of excised tissue (315) in the fluid circuit through which the blood flows, and a photoplethysmographic device including an emitter and a photodetector (330) positioned on the tissue (335, 340) so that a portion of the light output by the emitter passes through the tissue and is incident on the photodetector. The method further includes the steps of energizing the pump mechanism (420) to move the blood through the tissue, energizing the emitter (425) to output light, collecting paired data from the photodetector and from one or more reference measurements (430), and processing the paired data to calibrate the photoplethysmographic device (435).