PortaLite

A portable cerebral oxygenation monitoring device


Publications using the PortaLite

Application of near-infrared spectroscopy in human elite freedivers while deep diving on a single breath hold

Near-infrared spectroscopy was used to observe the cerebral hemodynamic response of freedivers during single breath-hold training dives. We observed variability in hemodynamic progression, and heartbeat shape changes with diving depth.

Changes in prefrontal cerebral oxygenation and microvascular blood volume in hypoxia and possible association with acute mountain sickness

The aim of this study was to evaluate changes in prefrontal cerebral oxygenation and microvascular blood volume during exercise in normobaric hypoxia and to investigate possible associations with the occurrence of acute mountain sickness (AMS) at …

MEDEX 2015: Prophylactic Effects of Positive Expiratory Pressure in Trekkers at Very High Altitude

Purpose: Positive expiratory pressure (PEP) breathing has been shown to increase arterial oxygenation during acute hypoxic exposure but the underlying mechanisms and consequences on symptoms during prolonged high-altitude exposure remain to be …

Mild poikilocapnic hypoxia increases very low frequency haemoglobin oxygenation oscillations in prefrontal cortex

Abstract Background The aim of the study was to investigate the effect of mild cerebral hypoxia on haemoglobin oxygenation (HbO 2 ), cerebrospinal fluid dynamics and cardiovascular physiology. To achieve this goal, four signals were recorded …

Decreased automaticity contributes to dual task decrements in older compared to younger adults

Purpose To contrast older and younger adults’ prefrontal cortex (PFC) neural activity (through changes in oxygenated hemoglobin) during single and dual tasks, and to compare decrements in task performance. Methods Changes in oxygenated hemoglobin of …

Determinants of orthostatic cerebral oxygenation assessed using near-infrared spectroscopy

Background To understand the relationship between blood pressure changes during standing up and clinical outcome, cerebral oxygenation needs to be measured, which may be performed using near-infrared spectroscopy (NIRS). However, the role of …

Effects of passive and active leg movements to interrupt sitting in mild hypercapnia on cardiovascular function in healthy adults

Prolonged sitting in a mild hypercapnic environment impairs peripheral vascular function. The effects of sitting interruptions using passive or active skeletal muscle contractions are still unclear. Therefore, we sought to examine the vascular …

Leg Fidgeting Improves Executive Function following Prolonged Sitting with a Typical Western Meal: A Randomized, Controlled Cross-Over Trial

Prolonged uninterrupted sitting and a typical Western meal, high in fat and refined sugar, can additively impair cognitive and cerebrovascular functions. However, it is unknown whether interrupting these behaviours, with a simple desk-based activity, …

Optimized electroencephalogram and functional near-infrared spectroscopy-based mental workload detection method for practical applications

Abstract Background Mental workload is a critical consideration in complex man–machine systems design. Among various mental workload detection techniques, multimodal detection techniques integrating electroencephalogram (EEG) and functional …

Acute Effects of Local Ischemic Hypoxia and Systemic Hypoxemia on Neuromuscular and Cognitive Function

Background: The application of blood flow restriction (BFR) induces local ischemic hypoxia within the muscle(s) distal to the restriction device. Systemic hypoxemia via oxygen or barometric pressure manipulation achieves whole-body hypoxia and thus …

Frailty influences the vascular responsiveness of elderly individuals with chronic heart failure

Introduction Frailty is highly prevalent in heart failure (HF) patients. HF is associated with oxidative stress and chronic inflammation, which impair oxygen use by skeletal muscles. Little is known about the influence of frailty on vascular …

Handgrip exercise induces sex‐specific mean arterial pressure and oxygenation responses but similar performance fatigability

Women exhibit an attenuated exercise pressor reflex (EPR) when compared to men. The influence of sex-specific mechanisms related to the EPR and performance fatigability remain to be fully elucidated. The purpose was to determine the impact of …

The influence of cardiovascular risk factors on near-infrared spectroscopy-derived muscle oxygen saturation during exercise recovery in older adults

Purpose Aging is typically accompanied by risk for cardiovascular disease (CVD), which both are associated with reduced muscle oxygen saturation (SmO2) during exercise recovery. However, the apart impact of aging and CVD risk factors on muscle …

Turmeric root extract supplementation improves pre-frontal cortex oxygenation and blood volume in older males and females: a randomised cross-over, placebo-controlled study

Ageing is associated with endothelial dysfunction and reduced cerebral blood flow and oxygenation. The present study aimed to investigate whether turmeric supplementation could improve cerebral oxygenation and blood volume during brain activation via …

Hemodynamic and structural brain measures in high and low sedentary older adults

Due to its cardiovascular effects sedentary behaviour might impact cerebrovascular function in the long term, affecting cerebrovascular regulatory mechanisms and perfusion levels. Consequently this could underly potential structural brain …

Approximate entropies of resting state continuous neurocardiovascular physiological signals are associated with physical frailty in older adults

Frailty in older adults is characterised by dysregulation in multiple physiological systems. The frailty phenotype is defined on the basis of exhaustion, unexplained weight loss, weakness, slowness and low physical activity (one or two: pre-frail; 3 …

Arterial Stiffness Responses to Prolonged Sitting Combined with a High Glycemic Index Meal: A Double-Blind, Randomized Cross-Over Trial

Regular exposure to uninterrupted prolonged sitting and the consumption of high glycemic meals (HGI) is independently associated with increased cardiovascular disease risk. Sitting for as little as 1-hour can impair the health of both peripheral and …

Cerebrovascular function response to prolonged sitting combined with a high‐glycemic index meal: A double‐blind, randomized cross‐over trial

Acute prolonged sitting leads to cerebrovascular disruptions. However, it is unclear how prolonged sitting interacts with other common behaviors, including high- (HGI) and low- glycemic index (LGI) meals. Using a double- blind randomized cross- over …

Measuring tibial hemodynamics and metabolism at rest and after exercise using near-infrared spectroscopy

The bone vascular system is important; yet, evaluation of bone hemodynamics is difficult and expensive. This study evaluated the utility and reliability of near-infrared spectroscopy (NIRS), a portable and relatively inexpensive device, in measuring …

The effect of muscle blood flow restriction on hemodynamics, cerebral oxygenation and activation at rest

This study tested the hypothesis that muscle blood flow restriction reduces muscle and cerebral oxygenation, at rest. In 26 healthy males, aged 33±2 yrs, physiological variables were continuously recorded during a 10-min period in two experimental …