Perfusion assessment using transmission laser speckle imaging

An apparatus for determining a metric of tissue perfusion, comprising:

• a coherent light source configured to illuminate a tissue sample;
• a detector, without a lens, system of lenses, mirror or any other optical instruments for creating a focused image, wherein the detector is configured to receive a plurality of light intensity values associated with an unfocused image of the tissue sample;
• and
• means for securing the coherent light source and the detector to the tissue sample in a fixed transmission geometry relative to the tissue sample, such that movement of the tissue sample while measuring tissue perfusion does not alter the transmission geometry,
• wherein the detector is configured to transfer the plurality of light intensity values to a processor configured to compute a speckle contrast parameter and to determine the metric of tissue perfusion.

A method of determining a metric of perfusion in a tissue sample, comprising:

• providing an apparatus comprising an enclosure configured to accommodate the tissue sample, a coherent light source configured to illuminate the tissue sample, and a detector, without a lens, system of lenses, mirror or any other optical instruments for creating a focused image, wherein the detector is configured to receive a plurality of light intensity values associated with an unfocused image of the tissue sample, and wherein the detector is configured to transfer data to a processor;
• placing the tissue sample into the enclosure between the coherent light source and the detector;
• transilluminating the tissue sample with the coherent light source rendering an unfocused image comprising a plurality of light intensity values, which are captured by the detector;
• transferring the light intensity values from the detector to the processor;
• computing, by the processor, a speckle contrast parameter based at least in part on the plurality of light intensity values;
• and
• determining, by the processor, the metric of perfusion from the speckle contrast parameter.