RESUMEN
Heart Rate Variability (HRV) has become an important risk assessment tool when diagnosing illnesses related to heart health. HRV is typically measured with an electrocardiogram; however, there are multiple studies that use Photoplethysmography (PPG) instead. Measuring HRV with video is beneficial as a non-invasive, hands-free alternative and represents a more accessible approach. We developed a methodology to extract HRV from video based on face detection algorithms and color augmentation. We applied this methodology to 45 samples. Signals obtained from PPG and video recorded an average mean error of less than 1 bpm when measuring the heart rate of all subjects. Furthermore, utilizing PPG and video, we computed 61 variables related to HRV. We compared each of them with three correlation metrics (i.e., Kendall, Pearson, and Spearman), adjusting them for multiple comparisons with the Benjamini-Hochberg method to control the false discovery rate and to retrieve the q-value when considering statistical significance lower than 0.5. Using these methods, we found significant correlations for 38 variables (e.g., Heart Rate, 0.991; Mean NN Interval, 0.990; and NN Interval Count, 0.955) using time-domain, frequency-domain, and non-linear methods.
Asunto(s)
Electrocardiografía , Fotopletismografía , Algoritmos , Electrocardiografía/métodos , Mano , Frecuencia Cardíaca/fisiología , Humanos , Fotopletismografía/métodosRESUMEN
To compare specular microscopy values obtained using the Perseus (CSO, Italy) and the Nidek CEM-530 (NIDEK Co., Ltd. Japan) specular microscopes. This prospective study used specular microscopy to examine sixty eyes from thirty healthy subjects (29.83 ± 9.41 years; range 18-79 years). This was done with both the Nidek CEM-530 and the Perseus on three occasions and results were evaluated by one independent observer. Measurement differences between instruments and agreement between devices were determined. The endothelial cell sample was larger with the Perseus than with the CEM-530 (235.92 ± 38.26 vs. 184.38 ± 43.88, respectively) with a statistically significant difference (P = 0.001). Mean endothelial cell density (ECD) with the Perseus and CEM-530 was 2692.75 ± 306.66 and 2556.47 ± 257.38 cells/mm(2) (P = 0.001), respectively; mean coefficient of variation (CV) was 33.43 ± 4.29 and 28.70 ± 3.82 (P = 0.001), respectively, and hexagonality 56.66 ± 6.19 % and 68.50 ± 3.64 (P = 0.001), respectively. The mean of the differences (Perseus minus CEM-530) for ECD was 136.27 ± 106.16 cells/mm(2) (95 % CI 108.85-163.70 cells/mm(2)); 4.73 ± 2.70 % (95 % CI 4.03-5.41) in CV; and -11.83 ± 5.05 for percentage of hexagonal cells. Both instruments showed significant differences in the measurement of all cell forms, predominantly higher values were found with the Perseus vs the CEM-530, except 4-sided cells. Endothelial cell density, coefficient of variation, and percentage of hexagonal cells between the Perseus and CEM-530 differ statistically. This shows that these instruments should not be used interchangeably.
Asunto(s)
Endotelio Corneal/citología , Microscopía/instrumentación , Adolescente , Adulto , Anciano , Recuento de Células , Forma de la Célula , Tamaño de la Célula , Estudios Transversales , Femenino , Voluntarios Sanos , Humanos , Masculino , Microscopía/métodos , Persona de Mediana Edad , Estudios ProspectivosRESUMEN
BACKGROUND: The noncontact mapping system facilitates the mapping of premature ventricular contractions (PVCs) and ventricular tachycardia (VT) using a 64-electrode expandable balloon catheter (ARRAY, St. Jude Medical). The aim of this study is to analyze the results and follow-up of the PVC ablation using this system. METHODS AND RESULTS: Prospective and consecutive patients with frequent PVCs (6,000 or more) or monomorphic VT, suspected to be originated on the right ventricular outflow tract (RVOT), were included. The balloon catheter was positioned in the RVOT. Eighteen patients, 9 women, mean age 48 years (youngest/oldest 19-65) were included. Sixteen patients presented no structural heart disease. The origin of the arrhythmia was RVOT (n = 15), right ventricular inflow tract (n = 1), and left ventricular outflow tract (n = 2). Acute success was achieved in 15 patients; in 2 patients radiofrequency was not applied due to security reasons (origin site close to left coronary artery origin). The mean follow-up was 15 months (min. 4, max. 26); 13 patients presented abolition of the arrhythmia without drugs and 1 patient required antiarrhythmic drugs for arrhythmia control (previously ineffective). As an only complication, a femoral artery-venous fistula was observed. CONCLUSIONS: The noncontact mapping system using a multielectrode balloon allows right ventricular arrhythmia treatment with a high rate of efficacy and safety.
Asunto(s)
Catéteres Cardíacos , Ablación por Catéter/instrumentación , Electrodos , Taquicardia Ventricular/cirugía , Complejos Prematuros Ventriculares/cirugía , Adulto , Anciano , Antiarrítmicos/uso terapéutico , Ablación por Catéter/efectos adversos , Diseño de Equipo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/fisiopatología , Factores de Tiempo , Resultado del Tratamiento , Complejos Prematuros Ventriculares/diagnóstico , Complejos Prematuros Ventriculares/fisiopatología , Adulto JovenRESUMEN
AIM: This study aimed to investigate the erosive potential of these drinks using human enamel in vitro. MATERIAL AND METHODS: A range of bottled, still flavoured water drinks available in the UK were investigated and their erosive potential was compared by measuring pH and titratable acidity. Six beverages were chosen for the main study and also both a negative (distilled water) and positive control (orange juice). Human enamel specimens were prepared, sectioned and varnished leaving an exposure window visible to have contact with test solutions. Each specimen was randomly allocated in groups of six. Each group was exposed to 20 ml of one of the eight test solutions for 10, 30, 60 and 90 min. Quantitative light-induced fluorescence was used to ensure the teeth selected were free of artefacts and diseased areas. Erosion was measured using non-contact optical profilometry. RESULTS: Enamel loss occurred with all test drinks and the positive control (p<0.05) and in most cases the still water drinks were just as erosive as the positive control. Only vitamin water at 30 min was not significantly different from the negative control (p= 0.86), All drinks tested resulted in significant enamel loss (p<0.01). These results may indicate that consumers should think of still water beverages as potentially acidic drinks rather than just flavoured healthy water alternatives. CONCLUSION: This study indicates the need for preventive advice to be given by dentists about such beverages and therefore ultimately to make patients and consumers more aware of hidden erosive risks.