Predicting neurally mediated syncope based on pulse arrival time: algorithm development and preliminary results.

Background: Neurally mediated syncope (NMS) is a common disorder that is triggered by orthostatic stress. The circulatory adjustments to orthostatic stress occur just prior to a sudden loss of consciousness. NMS prediction would protect patients from falls or accidents.

Performance evaluation of a tri-axial accelerometry-based respiration monitoring for ambient assisted living.

Ambient Assisted Living (AAL) technology is often proposed as a way to tackle the increasing cost of healthcare caused by population aging. However, the sensing technology for continuous respiratory monitoring at home is lacking. Known approaches of respiratory monitoring are based on measuring either respiratory effect, e.

Hemodynamic response to visual stimulation in newborn infants using functional near-infrared spectroscopy.

Brain activity is associated with physiological changes, which alter the optical properties of tissue. These changes can be detected by near-infrared spectroscopy (NIRS). Aim of the study was to determine changes in cerebral oxygenation in response to stimulation in the visual cortex in newborn infants during spontaneous sleep in the first days of life.

Sensitivity of detrended fluctuation analysis applied to heart rate variability of preterm newborns.

Detrended fluctuation analysis (DFA), a fractal analysis method which is widely used in heart rate variability (HRV) studies, is used to analyze the scaling behaviour of RR interval series of preterm neonates. The average scaling behaviour, calculated using 30000 RR intervals (3 - 4 hours), is characterized by a scaling exponent of 1.4 ± 0.

Do GSM 900MHz signals affect cerebral blood circulation? A near-infrared spectrophotometry study.

Effects of GSM 900MHz signals (EMF) typical for a handheld mobile phone on the cerebral blood circulation were investigated using near-infrared spectrophotometry (NIRS) in a three armed (12W/kg, 1.2W/kg, sham), double blind, randomized crossover trial in 16 healthy volunteers. During exposure we observed borderline significant short term responses of oxyhemoglobin and deoxyhemoglobin concentration, which correspond to a decrease of cerebral blood flow and volume and were smaller than regular physiological changes.

Triphasic MRI of pelvic organ descent: sources of measurement error.

Purpose: To identify sources of error when measuring pelvic organ displacement during straining using triphasic dynamic magnetic resonance imaging (MRI).

Materials And Methods: Ten healthy nulliparous woman underwent triphasic dynamic 1.5 T pelvic MRI twice with 1 week between studies.

Rectal pressure response to a meal in patients with high spinal cord injury.

Objectives: To determine whether there is a postprandial increase of rectal pressure in patients with spinal cord injury (SCI) and to compare their rectal pressures with those of healthy volunteers.

Design: A before-after trial comparing SCI and control subjects.

Setting: Patients were recruited from the register of an SCI unit at a rehabilitation medicine department, and the study took place at the university hospital laboratory in Sweden.

Quantitation of the concordance between cerebral intravascular oxygenation and mean arterial blood pressure for the detection of impaired autoregulation.

Since some important forms of brain injury in premature infants are caused in considerable part by disturbances in cerebral blood flow (CBF), it is important to be able to detect whether the cerebrovascular autoregulation, the mechanism by which CBF is maintained constant despite alterations in mean arterial blood pressure (MAP), is working properly. A recent study suggested that concordant changes in MAP and cerebral intravascular oxygenation (HbD), measured non-invasively by near-infrared spectroscopy (NIRS) as the difference between the concentration changes of oxygenated hemoglobin (HbO2) and deoxygenated hemoglobin (Hb), reflect impaired cerebrovascular autoregulation. Consequently, premature infants with impaired cerebrovascular autoregulation could be identified by simultaneous, continuous measurements of HbD and MAP.

Measurement of tissue oxygenation index during the first three days in premature born infants.

No normal values of tissue oxygenation index (TOI) of the brain are known regarding premature born infants. We measured TOI, a measure for the cerebral hemoglobin oxygen saturation, on the head of 15 preterm infants with a median postmenstrual age of 28 weeks (interquartile range (IQR) between 26-29 weeks) with spatially resolved spectroscopy (NIRO 300, Hamamatsu) during the first three days of life. Infants with intra-ventricular hemorrhage or periventricular leucomalacia before the first measurement, as shown by ultrasound, were excluded.