Systems and methods for pedal revascularization assessment

Inventors

Lee, Kijoon • Dong, Jing • Bi, Renzhe

Assignees

Pedra Technology Pte Ltd

Abstract

Diffuse optical flow (DOF) sensors can be used to assess deep tissue flow. DOF sensors positioned on a foot can provide fluctuating light intensity data to an analyzer, which can then determine absolute and/or relative blood flow. The determined absolute and/or relative blood flow can be signaled to an operator, for example a surgeon for intra-operative use. DOF sensors may be utilized to assess pedal revascularization, for example to guide interventional procedures and to evaluate their efficacy. A support structure can carry a plurality of DOF sensors, such that when the support structure is placed onto a patient's foot, the DOF sensors are disposed adjacent different locations on the foot. The different locations may correspond to different topographical regions of the foot, for example different pedal angiosomes.

Core Innovation

The invention provides a system and method for intra-operative, real-time assessment of peripheral blood flow characteristics in deep tissue using diffuse optical flow (DOF) sensors. A support structure is configured to be positioned onto an external body part of a patient, with at least one DOF sensor in optical communication with a skin surface and configured to capture light scattered diffusively into tissue and transmitted at a depth of penetration of between 5 mm and 50 mm. The DOF sensor includes a return optical conduit and at least one input optical fiber in optical communication with a coherent laser light source, and a photodetector is operably connected to the DOF sensor.

A processor analyzes data from the at least one DOF sensor to determine blood flow characteristics at a location near the DOF sensor when the support structure is positioned onto the external body part. The processor determines a spatial speckle contrast ratio (Ks) and/or a temporal speckle contrast ratio (Kt), and determines 1/Ks2 and/or 1/Kt2 from intensity fluctuations. The processor correlates the determined 1/Ks2 or 1/Kt2 values with blood flow, and thereby determines blood flow characteristics in blood vessels of the patient near the sensor.

The system and methods further support assessment across multiple topographical locations of an extremity, including different angiosomes, by using a plurality of DOF sensors disposed at respective plurality of locations. In this configuration, the plurality of locations corresponds to different topographical locations including different angiosomes, and blood flow characteristics are determined at each location via a processor. The determined blood flow characteristics are signaled to an operator, including feedback modalities such as visual, audible, or tactile indicia, and the feedback is provided in real time.

Claims Coverage

The document provides three independent claims: a system claim and two method claims. Across the independent claims, the inventive features focus on DOF sensing with coherent laser light and return optical conduit, determining blood flow from speckle contrast ratios with correlation of 1/Ks^2 or 1/Kt^2 to blood flow at 5–50 mm penetration depth, and angiosome/topographical mapping using multiple sensor locations and signaling results to an operator.

Across the independent claims, the coverage centers on DOF-based determination of peripheral blood flow characteristics using spatial and/or temporal speckle contrast ratios (Ks/Kt) to compute and correlate 1/Ks^2 or 1/Kt^2 with blood flow at 5–50 mm penetration depth, combined with support or sensor disposition proximate the skin and signaling of determined blood flow characteristics to an operator, including multi-location angiosome-relevant assessment using multiple DOF sensors.

Stated Advantages

Documented Applications