Covidien Ag

University of California

Covidien LP

Laser Associated Sciences, Inc.

Bruce Yee Yang

Sean Michael White

Tyler Bywaters Rice

Tyler Rice

Bruce J Tromberg

Bernard H Choi

Petra Wilder-Smith

Caitlin Regan

Michael Ghijsen

Methods and apparatus for measuring perfusion using transmission laser speckle imaging are provided. The apparatus comprises a coherent light source and a detector configured to measure transmitted light associated with an unfocused image at one or more locations. The coherent light source and detector are positioned in a transmission geometry. The apparatus further comprises means for securing the coherent light source and the detector to the tissue sample in a fixed transmission geometry relative to the tissue sample. The apparatus may further comprise at least one processor to receive information from the detector and process detected variations in transmitted light intensity to determine a single metric of perfusion. The method may comprise the steps transilluminating a tissue sample with coherent light, recording spatial and/or temporal variations in the transmitted light signal, determining speckle contrast value(s), and computing a metric of perfusion.

Perfusion assessment using transmission laser speckle imaging

In some examples, a system includes processing circuitry configured to generate a laser speckle contrast signal based on a received signal indicative of detected light, wherein the detected light is scatted by tissue from a coherent light source. The processing circuitry may also determine, from the laser speckle contrast signal, a flow value and determine, from the laser speckle contrast signal, a waveform metric. Based on the flow value and the waveform metric, the processing circuitry may determine a blood flow metric for the tissue and output a representation of the blood flow metric.

Determining blood flow using laser speckle imaging

Devices, systems, and methods are disclosed for improved laser speckle imaging of samples, such as vascularized tissue, for the determination of the rate of movement of light scattering particles within the sample. The system includes a structure adjoining a light source and a photo-sensitive detector. The structure can be positioned adjacent the sample (e.g., coupled to the sample) and configured to orient the light source and detector relative the sample such that surface reflections, including specular reflections and diffuse reflections, are discouraged from entering the detection field of the detector. The separation distance along the structure between the light source and the detector may further enable selective depth penetration into the sample and biased sampling of multiply scattered photons. The system includes an operably coupled processor programmed to derive contrast metrics from the detector and to relate the contrast metrics to a rate of movement of the light scattering particles.

System for blood flow measurement with affixed laser speckle contrast analysis

Disclosed herein are systems, methods, and devices for calibrating contrast measurements from laser speckle imaging systems to accurately determine unknown particle motion characteristics, such as flow rate. The calibration stores to memory calibration data, which may include a set of measurements from samples with known particle characteristics and/or estimates of noise, including the effects on contrast arising from undesired signals unrelated to the unknown particle motion characteristics. The calibration data may be accessed and used to correct an empirical measurement of contrast and/or interpolate a value of the unknown particle motion characteristic. The system may include a light source, photodetector, processor, and memory, which can be combined into a single device, such as a wearable device, for providing calibrated flow measurements. The device may be used, for example, to measure blood flow, cardiac output, and heart rate, and can be used to amplify the pulsatile signal.

Systems and methods for calibrating and correcting a speckle contrast flowmeter

Disclosed herein are methods and apparatus for diagnosing a disease in the gingival region of an individual, comprising: quantitatively measuring blood flow or changes in blood flow in the gingival region of the individual, potentially comparing these data to that of a healthy subject, and diagnosing the disease based one of more of these quantities.

Methods and apparatus for the assessment of gingival blood flow

Systems and methods are disclosed for determining physiological information in a subject. The system includes: a light source positionable along a first location outside of the subject; a photo-sensitive detector positionable along a second location outside of the subject and configured to detect scattered light and generate a signal; a processor having a program and a memory, wherein the processor is operably coupled to the detector and configured to receive and store the signals generated over a period of time; wherein the processor is programmed to derive contrast metrics from the stored signals, calculate a waveform from the contrast metrics, decompose the waveform into basis functions and respective amplitudes, and compare the basis function amplitudes to determine the physiological information.

Growing community of inventors

Irvine, CA, United States of America

Bruce Yee Yang