A Pilot Study to Evaluate Multi-Spectral and Laser Speckle Imaging and Multiphoton Microscopy During Vascular Occlusion

Study Overview
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Brief Summary
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The purpose of this research is to evaluate and validate the performance of non-invasive imaging modalities for assessment of skin. A pressure cuff occlusion will be used to stimulate blood flow dynamic that these instruments are designed to sense. The researcher currently plan to assess only basic feasibility of the imaging instruments.

Detailed Description
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The primary reason for including pressure cuff occlusion in this protocol is to test the performance of Multi-Spectral Imaging and Laser Speckle Imaging can measure in the full range of vascular conditions ranging from ischemic (under-perfused or unsaturated) to hyperemic (over-perfused and over-saturated). Modulated Imaging a non-contact optical imaging technology can detect the concentration of total hemoglobin, deoxygenated and oxygenated hemoglobin in absolute amounts in units of millimoles / unit volume of tissue measured. Laser Speckle Imaging a non-contact optical imaging technology consists of a coherent light source, camera, and image acquisition system. This image device can measure and compare relative flow in vasculature at varied time points.

Official Title
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A Pilot Study to Evaluate Multi-Spectral Imaging (MI) and Laser Speckle Imaging (LSI) and Multiphoton Microscopy (MPM) During Vascular Occlusion

Conditions
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Abnormal Vascular Flow

Intervention / Treatment
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* Device: Multi-Spectral and Laser Speckle Imaging


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male and female adult 18 years and older Exclusion Criteria: Younger than 18 years of age Pregnant women

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Vascular Occlusion<br>Multi-Spectral and Laser Speckle Imaging | Device: Multi-Spectral and Laser Speckle Imaging<br>* Changes in skin tissue and blood flow.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Skin blood flow | The key factor of interest is measuring the changes in the fluorescence signal of the epidermal cells during the arm occlusion, which will provide information about changes in cellular metabolism during cellular oxygen deprivation. Time series of optical sections (two-dimensional x-y images parallel to the skin surface of about 250x250 µm2) at the same depth will be obtained before, during and after the arm occlusion. The images will be based on two-photon excitation of endogenous fluorophores (NADH). To quantify the fluorescence signal, which will provide information about changes of cellular metabolism, we will use the integrated brightness of each image (same rectangular area for all images) as a measure of the signal. The integrated brightness is defined as the sum of pixels weighted over the brightness values (or gray values) of the pixel. A statistical plan is not appropriate at this stage of the pilot study. | 4 weeks |