Search results for "Plethysmograph"
showing 10 items of 94 documents
A validity and reliability study of Conditional Entropy Measures of Pulse Rate Variability
2019
In this work, we present the feasibility to use a simpler methodological approach for the assessment of the short-term complexity of Heart Rate Variability (HRV). Specifically, we propose to exploit Pulse Rate Variability (PRV) recorded through photoplethysmography in place of HRV measured from the ECG, and to compute complexity via a linear Gaussian approximation in place of the standard model-free methods (e.g., nearest neighbor entropy estimates) usually applied to HRV. Linear PRV-based and model-free HRV-based complexity measures were compared via statistical tests, correlation analysis and Bland-Altman plots, demonstrating an overall good agreement. These results support the applicabil…
Cinnamon extract inhibits allergen-specific immune responses in human and murine allergy models.
2019
Background Ceylon cinnamon has been shown to possess anti-inflammatory properties in many diseases including allergic inflammation. Objective The aim of this study was to analyse in more detail the effects of cinnamon extract (CE) and its major compounds p-cymene and trans-cinnamaldehyde (CA) on allergen-specific immune responses in vitro and in vivo. Methods Therefore, monocyte-derived mature dendritic cells (DC) from grass or birch pollen allergic donors were pulsed with the respective allergen in the presence or absence of CE, p-cymene, CA or the solvent ethanol and co-cultured with autologous CD4+ T cells. Furthermore, basophil activation test was performed with or without CE or ethanol…
Comparison of Unfractionated Versus Low Molecular Weight Heparin for Deep Vein Thrombosis Prophylaxis During Breast and Pelvic Cancer Surgery: Effica…
1998
In a prospective, double-blind randomized trial the efficacy and safety of low molecular weight heparin and un fractionated heparin were compared for the prevention of post operative deep vein thrombosis in patients undergoing major surgery for breast and pelvic cancer. Three hundred fifty-eight patients were randomly allocated to the two treatment groups. Thirty-four of these were excluded from the study. Of the re maining 324 patients, 164 received 5000 IU unfractionated heparin three times daily and 160 received 3000 anti-Xa units of low molecular weight heparin once daily. Treatment was started 2 to 5 hours preoperatively and continued for 7 days. The occurrence of deep vein thrombosis…
Adaptive scheduling of acceleration and gyroscope for motion artifact cancelation in photoplethysmography
2022
Background and objective: Recently, various algorithms have been introduced using wrist-worn photo-plethysmography (PPG) to provide high accuracy of instantaneous heart rate (HR) estimation, including during high-intensity exercise. Most studies focus on using acceleration and/or gyroscope signals for the motion artifact (MA) reference, which attenuates or cancels out noise from the MA-corrupted PPG signals. We aim to open and pave the path to find an appropriate MA reference selection for MA cancelation in PPG.Methods: We investigated how the acceleration and gyroscope reference signals correlate with the MAs of the distorted PPG signals and derived both mathematically and experimentally a…
Clinical-anamnestic and instrumental data in outpatients suffering from venous disease
1995
The authors studied 200 consecutive outpatients with symptoms due to venous disease of the lower limbs. All the patients underwent anamnestic, clinical and instrumental evaluation (c.w. Doppler velocimetry and strain-gauge plethysmography). The results of this study showed that some anamnestic and clinical data are significantly related to venous disease detected by instrumental techniques. The superficial and deep vein hypertension were, instead, correlated to oral contraceptive use.
Optical noninvasive monitoring of skin blood pulsations
2005
Time-resolved detection and analysis of skin backscattered optical signals (remission photoplethysmography or PPG) provide rich information on skin blood volume pulsations and can serve for reliable cardiovascular assessment. Single- and multiple-channel PPG concepts are discussed. Simultaneous data flow from several locations on the human body allows us to study heartbeat pulse-wave propagation in real time and to evaluate vascular resistance. Portable single-, dual-, and four-channel PPG monitoring devices with special software have been designed for real-time data acquisition and processing. The prototype devices have been clinically studied, and their potential for monitoring heart arrh…
Sulodexide and the microcirculatory component in microphlebopathies.
1992
A double-blind, placebo-controlled study was carried out in 36 patients, aged 30 to 50 years, to evaluate the effectiveness of oral sulodexide in the treatment of chronic venous insufficiency due to idiopathic varices. Patients were allocated at random to receive either oral sulodexide as 2 capsules (each containing 250 lipoproteinolipase releasing units) twice daily or 2 identical placebo capsules twice daily over a period of 45 days. Using strain gauge plethysmographic data, assessments were made of the microcirculatory effects of treatment by calculating the coefficient of capillary filtration from measurements made on both legs of each patient on entry and after 30 and 45 days of treatm…
Evaluation of regional haemodynamics and alterations of vascular wall of the lower limbs in hypertensive subjects
1995
This study was designed to analyse the relationship between arterial hypertension and changes in arterial blood flow and vascular wall damage of the lower limbs in hypertensive patients with various degrees of hypertension. Six hundred and fifty-four hypertensive patients (421 males and 233 females) aged 35 to 70 years and 88 healthy subjects (63 males and 25 females) aged 39 to 60 years were studied. Strain-gauge plethysmography of the lower limbs was used to calculate arterial calf blood flow (RF), arterial calf blood flow after post-ischaemic hyperaemia (PF), basal and minimal vascular resistances (BVR and MVR), time to reach peak flow (tPF), time until 50% reduction of peak flow (tT1/2)…
Low relative resting metabolic rate and body weight gain in adult Caucasian Italians
2005
OBJECTIVE: To investigate the relationship between resting metabolic rate (RMR) and subsequent changes in body size and degree of fatness in a group of adult Caucasian Italians. DESIGN: Prospective, longitudinal, observational study. SUBJECTS: In total, 155 subjects (72 males and 83 females, age range: 18–55 y; BMI: 17.5–63.4 kg/m2) were evaluated. In total, 43 (26 m and 17 f; BMI: 28.971.1 kg/m2, mean7s.e.m.) of them were reassessed 10–12 y later. MEASUREMENTS: Anthropometric and body composition (bioimpedance analysis) parameters and RMR (indirect calorimetry) were taken at baseline and after 10–12 y. RESULTS: Subjects (15 m, 8 f) who gained body weight (arbitrarily defined as a change in…
Cardiovascular effects of impulse noise, road traffic noise, and intermittent pink noise at LAeq = 75 dB, as a function of sex, age, and level of anx…
1992
In a previous paper, in which the experimental conditions of the present research are fully described (Parrot et al., this issue), heart rate (HR) was studied in 60 male and in 60 female subjects in response to a pile-driver noise (P), a gunfire noise (G), a road traffic noise (T), and an intermittent pink noise (R), all noises being emitted at the same LAeq = 75 dB for 15 min. Digital pulse level (PL) responses were concomitantly surveyed by the use of pulse oximetry, allowing continuous arterial oxygen saturation (SaO2) readings. An index of pulse reactivity (PRI) could be calculated. Arterial blood pressure was measured 7 times from the beginning to the end of each trial. At rest, within…