Abstract: Methods, systems, and related computer program products for the non-invasive spectrophotometric monitoring of a biological volume having multiple tissue layers are described. Aggregate absorption and scattering properties are measured for each of a plurality of predetermined source-detector separation distances along a surface of the biological volume, the measurement being based on a model of the biological volume as a single-layer, semi-infinite, homogeneous volume. A predetermined multi-layer tissue model is retrieved that characterizes a mathematical relationship among (a) absorption and scattering properties of each layer of a multi-layer tissue structure, and (b) aggregate absorption and scattering properties of the multi-layer tissue structure as would be measured at selected source-detector separation distances along a surface thereof.

Abstract: Systems, methods, and related computer program products for non-invasive NIR spectrophotometric (NIRS) monitoring of total blood hemoglobin levels and/or other blood constituent levels based on a hybrid combination of phase modulation spectrophotometry (PMS) and continuous wave spectrophotometry (CWS) are described. PMS-based measurements including both amplitude and phase information used in the determination of a non-pulsatile component of an absorption property for each of at least three distinct wavelengths are processed to compute PMS-derived intermediate information at least partially representative of a scattering characteristic. CWS-based measurements including amplitude information is processed in conjunction with the PMS-derived intermediate information to compute a pulsatile component of the absorption property.

Abstract: Methods, systems, and related computer program products for the non-invasive spectrophotometric monitoring of an optical property of a tissue volume are described. Multiple optical signals having different modulation frequencies are introduced into the tissue volume simultaneously and on a continuous basis throughout the monitoring session. Multiple optical signal portions incident upon each of a plurality of optical detectors are detected and separated based on their modulation frequency. Amplitude and phase signals corresponding to each optical signal portion are extracted and processed to determine the optical property of the tissue volume. In one preferred embodiment, a first optical detector includes an aperture having a central area, a first edge positioned nearer to a first optical source than the central area, and a second edge positioned farther from the first optical source than the central area. The first and second edges are each curved concavely toward the first optical source.

Abstract: Methods, systems, and related computer program products for non-invasive spectrophotometric monitoring of an optical property of a medium are described. Respective light portions are propagated through respective at least partially non-overlapping subregions of the medium during each of a calibration interval and a subsequent monitoring interval. Detections of the light portions acquired during the calibration interval are processed to compute at least one algorithm compensation that causes a first result related to the optical property for the first subregion to be substantially equal to a second result related to the optical property for the second subregion. Subsequently, detections of respective light portions acquired during the monitoring interval are processed in conjunction with the at least one algorithm compensation to compute a monitoring result for the optical property.

Abstract: Non-invasive spectrophotometric monitoring of oxygen saturation levels based on a combination of continuous wave spectrophotometry (CWS) and phase modulation spectrophotometry (PMS) is described. First information representative of absolute oxygen saturation levels in relatively shallow regions of a patient tissue volume are acquired from PMS-based monitoring thereof during a reference interval. Second information representative of non-absolute oxygen saturation levels in relatively deep regions of the tissue volume are acquired from CWS-based monitoring thereof during the reference interval. Based on the first and second information acquired during the reference interval, a mapping is automatically determined between the second information and estimated absolute oxygen saturation metrics for the relatively deep regions.

Abstract: Methods, systems, and related computer program products for are described for non-invasive detection of intracranial pressure (ICP) variations in an intracranial compartment of a patient. Optical radiation is propagated transcranially into the intracranial compartment, and optical radiation that has migrated through at least a portion of the intracranial compartment and back out of the cranium is detected. At least one signal representative of the detected optical radiation is processed to extract therefrom at least one component signal that varies in time according to at least one of an intrinsic physiological oscillation and an externally driven oscillation in the patient. Examples of suitable intrinsic physiological oscillations include intrinsic respiratory and cardiac oscillations. Examples of suitable externally driven oscillations include ventilated respiratory oscillations and externally mechanically induced oscillations.

Abstract: The present invention relates to a non-invasive optical system equipped with optical tomographic scanning method and algorithm for quantifying scattering and absorption properties and chromophore concentrations of highly scattering medium such as biological tissues, for 3D mapping and imaging reconstruction of the spatial and temporal variations in such properties. The invention further relates to a method and an apparatus for simultaneous measurement of concentrations of biochemical substances and blood oxygen saturation inside a biological tissue and arterial blood.

Abstract: Methods, systems, and related computer program products for non-invasive monitoring of a biological volume, such as a human brain, are described. In one preferred embodiment, each of a plurality of optical sources emits optical radiation into the biological volume each of a plurality of optical detectors detects optical radiation impinging thereupon from the biological volume. The optical measurements are processed to compute a requisite property value associated with each source-detector pair. For each source-detector pair, a volumetric basis region corresponding thereto is weighted by the requisite property value, the volumetric basis region being predetermined and representative of an estimated subvolume of the biological volume encountered by optical radiation emitted from that source and propagating to that detector. The weighted volumetric basis regions are accumulated into a volumetric cumulative array, and a display output is generated based at least in part on the volumetric cumulative array.