Analysis of peripheral arterial disease (PAD) patients by laser speckle measurement techniques.

Diabetic foot is a well-known problem among patients suffering from peripheral arterial diseases (PAD). This article presents an optical sensor for contactless measurement of the anatomical site based on laser speckle techniques. The sensor illuminates the inspected tissue and analyzes the captured back-reflected light from the time-changing speckle patterns. An occlusion test was implemented to provide a statistical parameter to differentiate between a low perfused and a healthy foot. A clinical study of 15 subjects was conducted. The video was analyzed by two methods: dynamic laser speckle (DLS) and laser speckle contrast analysis (LASCA). Data analysis included several classification models, where the KNN model exhibited maximum performance. These findings suggest that a simple and inexpensive system for PAD monitoring can be designed for home use and/or in community clinics.

Large-scale clinical validation of noncontact and continuous extraction of blood pressure via multipoint defocused photonic imaging.

Blood pressure (BP) is usually measured either invasively, by an intra-arterial catheter, or noninvasively, by a cuff-based sphygmomanometer. While the invasive method is continuous and more accurate, it has the risk of infection and generally is not comfortable for the patient. On the other hand, the cuff-based measurement is safer but less reliable and infrequent. Therefore, a reliable continuous noninvasive BP measurement is highly desirable. In this work, we propose a remote optical system, based on temporal analysis of secondary reflected speckle patterns, for computing a subject's pulse transit time (PTT). Afterward, a model is proposed and clinically validated for converting the PTT value into systolic and diastolic blood pressure. A full statistical analysis is performed over a comparison to a reference device (SOMNOtouch).

Speckle-based configuration for simultaneous in vitro inspection of mechanical contractions of cardiac myocyte cells.

An optical lensless configuration for a remote noncontact measuring of mechanical contractions of a vast number of cardiac myocytes is proposed. All the myocytes were taken from rats, and the measurements were done in an in vitro mode. The optical method is based on temporal analysis of secondary reflected speckle patterns generated in lensless microscope configuration. The processing involves analyzing the movement and the change in the statistics of the secondary speckle patterns that are created on top of the cell culture when it is illuminated by a spot of laser beam. The main advantage of the proposed system is the ability to measure many cells simultaneously (∼1000 cells) and to extract the statistical data of their movement at once. The presented experimental results also include investigation of the effect of isoproteranol on cell contraction process.