title: Handheld, point-of-care laser speckle imaging.
abstract: Laser speckle imaging (LSI) enables measurement of relative changes in blood flow in biological tissues. We postulate that a point-of-care form factor will lower barriers to routine clinical use of LSI. Here, we describe a first-generation handheld LSI device based on a tablet computer. The coefficient of variation of speckle contrast was  < 2% after averaging imaging data collected over an acquisition period of 5.3 s. With a single, experienced user, handheld motion artifacts had a negligible effect on data collection. With operation by multiple users, we did not identify any significant difference (p > 0.05) between the measured speckle contrast values using either a handheld or mounted configuration. In vivo data collected during occlusion experiments demonstrate that a handheld LSI is capable of both quantitative and qualitative assessment of changes in blood flow. Finally, as a practical application of handheld LSI, we collected data from a 53-day-old neonate with confirmed compromised blood flow in the hand. We readily identified with LSI a region of diminished blood flow in the thumb of the affected hand. Our data collectively suggest that handheld LSI is a promising technique to enable clinicians to obtain point-of-care measurements of blood flow.
authors: University of California-Irvine, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road East, Irvine, California 92612, United StatesbUniversity of California-Irvine, Department of Biomedical Engineering, 3120 Natural Sciences II, Irvine, California 92697, United States.
authors: Ryan
authors: R
authors: Farraro
authors: University of California-Irvine, Department of Pediatrics, 505 South Main Street, Irvine, Orange, California 92868, United States.
authors: Omid
authors: O
authors: Fathi
authors: University of California-Irvine, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road East, Irvine, California 92612, United StatesbUniversity of California-Irvine, Department of Biomedical Engineering, 3120 Natural Sciences II, Irvine, California 92697, United StatesdUniversity of California-Irvine, Department of Surgery, 333 City Boulevard West, Suite 1600, Orange, California 92868, United StateseUniversity of California-Irvine, Edwards Lifesciences Center for Advanced Cardiovascular Technology, 2400 Engineering Hall, Irvine, California 92697, United StatesfCHOC Children's Hospital, 1201 West La Veta Avenue, Orange, California 92868, United States.
authors: Bernard
authors: B
authors: Choi
mesh_terms: D001808:Blood Vessels / Q000000981:diagnostic imaging; D034201:Computers, Handheld; D003952:Diagnostic Imaging / Q000295:instrumentation*; D006225:Hand / Q000098:blood supply / Q000000981:diagnostic imaging*; D006801:Humans; D007223:Infant; D017078:Laser-Doppler Flowmetry / Q000295:instrumentation; D007834:Lasers; D019095:Point-of-Care Systems; D012039:Regional Blood Flow