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.

A Contact-Free Optical Device for the Detection of Pulmonary Congestion-A Pilot Study.

BACKGROUND: The cost of heart failure hospitalizations in the US alone is over USD 10 billion per year. Over 4 million Americans are hospitalized every year due to heart failure (HF), with a median length of stay of 4 days and an in-hospital mortality rate that exceeds 5%. Hospitalizations of patients with HF can be prevented by early detection of lung congestion. Our study assessed a new contact-free optical medical device used for the early detection of lung congestion. METHODS: The Gili system is an FDA-cleared device used for measuring chest motion vibration data. Lung congestion in the study was assessed clinically and verified via two cardiologists. An algorithm was developed using machine learning techniques, and cross-validation of the findings was performed to estimate the accuracy of the algorithm. RESULTS: A total of 227 patients were recruited (101 cases vs. 126 controls). The sensitivity and specificity for the device in our study were 0.91 (95% CI: 0.86-0.93) and 0.91 (95% CI: 0.87-0.94), respectively. In all instances, the observed estimates of PPVs and NPVs were at least 0.82 and 0.90, respectively. The accuracy of the algorithm was not affected by different covariates (including respiratory or valvular conditions). CONCLUSIONS: This study demonstrates the efficacy of a contact-free optical device for detecting lung congestion. Further validation of the study results across a larger and precise scale is warranted.

A novel contact-free atrial fibrillation monitor: a pilot study.

Aims: Atrial fibrillation (AF) is a major cause of morbidity and mortality. Current guidelines support performing electrocardiogram (ECG) screenings to spot AF in high-risk patients. The purpose of this study was to validate a new algorithm aimed to identify AF in patients measured with a recent FDA-cleared contact-free optical device. Methods and results: Study participants were measured simultaneously using two devices: a contact-free optical system that measures chest motion vibrations (investigational device, 'Gili') and a standard reference bed-side ECG monitor (Mindray®). Each reference ECG was evaluated by two board certified cardiologists that defined each trace as: regular rhythm, AF, other irregular rhythm or indecipherable/missing. A total of 3582, 30-s intervals, pertaining to 444 patients (41.9% with a history of AF) were made available for analysis. Distribution of patients with active AF, other irregular rhythm, and regular rhythm was 16.9%, 29.5%, and 53.6% respectively. Following application of cross-validated machine learning approach, the observed sensitivity and specificity were 0.92 [95% confidence interval (CI): 0.91-0.93] and 0.96 (95% CI: 0.95-0.96), respectively. Conclusion: This study demonstrates for the first time the efficacy of a contact-free optical device for detecting AF.

Validation of a novel contact-free heart and respiratory rate monitor.

There is a growing need for remote monitoring of patients due to a lack of resources and infection control. Current systems use sensors that require constant physical contact with the user, which may result in discomfort or lack of adherence. In the present study, we evaluated the accuracy of a new contact-free system to monitor heart and respiratory rate. Study participants were measured simultaneously using two devices: a contact-free optical system that measures nano-vibrations and movements (investigational device, "Gili Pro BioSensor") and a standard reference bed-side monitor, inclusive of an electrocardiogram and capnograph modules (Mindray®). Co-primary endpoints included HR and RR accuracy in subjects without active arrhythmias for HR, and for all study populations for RR (i.e., for subjects with and without active arrhythmias). Confirmatory secondary endpoints included HR scored continuously for all study populations, inclusive of subjects with arrhythmias. The present study included 115 patients who completed study procedures. Mean age was 66 ± 14.6 (range 29-93) with 60% males, 31% obese patients (i.e., BMI > 30 kg/m2, range 17-44) and 56% measured in a chair. For the dichotomised accuracy analysis, both co-primary endpoint for HR and RR resulted in 100% accuracy (95% CI: HR 98.8-100%; RR 98.9-100%), whereas for the confirmatory secondary analysis, 99.1% of the HR measurements across subjects with and without active arrhythmias were deemed accurate (95% CI: 97.4-99.8%). The current study demonstrated over 99% accuracy in detecting heart and respiratory rate using a novel contact-free optical system.

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).

Developing a 670k genotyping array to tag ~2M SNPs across 24 horse breeds.

BACKGROUND: To date, genome-scale analyses in the domestic horse have been limited by suboptimal single nucleotide polymorphism (SNP) density and uneven genomic coverage of the current SNP genotyping arrays. The recent availability of whole genome sequences has created the opportunity to develop a next generation, high-density equine SNP array. RESULTS: Using whole genome sequence from 153 individuals representing 24 distinct breeds collated by the equine genomics community, we cataloged over 23 million de novo discovered genetic variants. Leveraging genotype data from individuals with both whole genome sequence, and genotypes from lower-density, legacy SNP arrays, a subset of ~5 million high-quality, high-density array candidate SNPs were selected based on breed representation and uniform spacing across the genome. Considering probe design recommendations from a commercial vendor (Affymetrix, now Thermo Fisher Scientific) a set of ~2 million SNPs were selected for a next-generation high-density SNP chip (MNEc2M). Genotype data were generated using the MNEc2M array from a cohort of 332 horses from 20 breeds and a lower-density array, consisting of ~670 thousand SNPs (MNEc670k), was designed for genotype imputation. CONCLUSIONS: Here, we document the steps taken to design both the MNEc2M and MNEc670k arrays, report genomic and technical properties of these genotyping platforms, and demonstrate the imputation capabilities of these tools for the domestic horse.

Noncontact speckle-based optical sensor for detection of glucose concentration using magneto-optic effect.

We experimentally verify a speckle-based technique for noncontact measurement of glucose concentration in the bloodstream. The final device is intended to be a single wristwatch-style device containing a laser, a camera, and an alternating current (ac) electromagnet generated by a solenoid. The experiments presented are performed in vitro as proof of the concept. When a glucose substance is inserted into a solenoid generating an ac magnetic field, it exhibits Faraday rotation, which affects the temporal changes of the secondary speckle pattern distributions. The temporal frequency resulting from the ac magnetic field was found to have a lock-in amplification role, which increased the observability of the relatively small magneto-optic effect. Experimental results to support the proposed concept are presented.

Evolutionary Genomics and Conservation of the Endangered Przewalski's Horse.

Przewalski's horses (PHs, Equus ferus ssp. przewalskii) were discovered in the Asian steppes in the 1870s and represent the last remaining true wild horses. PHs became extinct in the wild in the 1960s but survived in captivity, thanks to major conservation efforts. The current population is still endangered, with just 2,109 individuals, one-quarter of which are in Chinese and Mongolian reintroduction reserves [1]. These horses descend from a founding population of 12 wild-caught PHs and possibly up to four domesticated individuals [2-4]. With a stocky build, an erect mane, and stripped and short legs, they are phenotypically and behaviorally distinct from domesticated horses (DHs, Equus caballus). Here, we sequenced the complete genomes of 11 PHs, representing all founding lineages, and five historical specimens dated to 1878-1929 CE, including the Holotype. These were compared to the hitherto-most-extensive genome dataset characterized for horses, comprising 21 new genomes. We found that loci showing the most genetic differentiation with DHs were enriched in genes involved in metabolism, cardiac disorders, muscle contraction, reproduction, behavior, and signaling pathways. We also show that DH and PH populations split ∼45,000 years ago and have remained connected by gene-flow thereafter. Finally, we monitor the genomic impact of ∼110 years of captivity, revealing reduced heterozygosity, increased inbreeding, and variable introgression of domestic alleles, ranging from non-detectable to as much as 31.1%. This, together with the identification of ancestry informative markers and corrections to the International Studbook, establishes a framework for evaluating the persistence of genetic variation in future reintroduced populations.

Role of KCNQ2 and KCNQ3 genes in juvenile idiopathic epilepsy in Arabian foals.

Juvenile idiopathic epilepsy (JIE) in Arabian foals resembles benign-familial neonatal convulsion (BFNC) syndrome, a rare idiopathic epilepsy of new-born humans. BFNC syndrome exhibits genetic heterogeneity, as has been hypothesised to occur in Arabian foals, and is known to be caused by mutations in the voltage-gated potassium channel subunit KCNQ2 and KCNQ3 genes. The close phenotypic characteristics of both Arabian foals and children suggest these epileptic syndromes are caused by the same genetic disorder. In horses, the KCNQ2 and KCNQ3 genes are located on the terminal region of chromosomes 22 and 9, respectively, essentially homologous to their location on chromosomes 20q13.3 and 8q24 in humans. Gene trees for the KCNQ2 and KCNQ3 genes between horses and other mammals, particularly humans and mice, were constructed and compared to widely accepted mammalian phylogenetic trees. The KCNQ2 gene tree exhibited close clustering between horses and humans, relative to horses and mice, in contrast to the evolutionary trees of other mammals. Distance values between the horse and human groups were lower as opposed to those found between the horse and mouse groups. The similarity between the horse and the human, especially for the KCNQ2 gene, where the majority of mutations causing BFNC have been found, supports the hypothesis of similar heritable and genetic patterns of the disease in both species and suggests that contrary to the classic mouse-model concept, humans may be a more suitable model for the study of JIE in Arabian foals.

Evolutionary dynamics of endogenous feline leukemia virus proliferation among species of the domestic cat lineage.

Endogenous feline leukemia viruses (enFeLVs) occur in the germ lines of the domestic cat and related wild species (genus Felis). We sequenced the long terminal repeats and part of the env region of enFeLVs in domestic cats and five wild species. A total of 305 enFeLV sequences were generated across 17 individuals, demonstrating considerable diversity within two major clades. Distinct proliferations of enFeLVs occurred before and after the black-footed cat diverged from the other species. Diversity of enFeLVs was limited for the sand cat and jungle cat suggesting that proliferation of enFeLVs occurred within these species after they diverged. Relationships among enFeLVs were congruent with host species relationships except for the jungle cat, which carried only enFeLVs from a lineage that recently invaded the germline (enFeLV-AGTT). Comparison of wildcat and domestic cat enFeLVs indicated that a distinctive germ line invasion of enFeLVs has not occurred since the cat was domesticated.