Chromatic thresholds were measured using the Cambridge Colour Test (CCT), the Colour Assessment and Diagnosis (CAD) test, and the Cone Specific Contrast Test (CSCT) at ground and 3780 m (12,400 ft) for subjects with normal color vision and red-green color vision defects. The CAD revealed a small (~10%) increase in the red-green thresholds for the trichromatic subjects and a similar increase in ...

For purposes of measuring oxygen saturation in the arterial blood of newly born infants (1) it became necessary to develop a rapid and reasonably accurate method for small blood samples. It was further necessary to demonstrate that cutaneous blood samples could be considered identical with specimens drawn directly from an artery. The present communication describes the calorimetric method evolv...

Several studies suggest that during early larval development of lower vertebrates convective blood flow is not essential to supply oxygen to the tissues, but information about the oxygenation status of larvae during the time of cutaneous respiration is still missing. If convective oxygen transport contributes to the oxygen supply to tissues, venous blood in the central circulatory system should...

We have investigated the application of ultrasound modulated coherent light for quantitative determination of the ratio of dye concentrations and total concentration of absorbers in a blood vessel-mimicking sample. A 3-mm-diam tube containing the mixture of dyes inside an Intralipid-based gel with optical properties similar to tissue was interrogated by two different laser wavelengths in combin...

Changes in local pulmonary capillary blood volume (Vc) and oxygen saturation (S) have been difficult to measure in live animals. By utilizing the differences in absorption of light at two wavelengths (650 and 800 nm), we estimated the fractional change in Vc and S during the course of the cardiac cycle in eight anesthetized, ventilated rabbits at low and high lung volumes. Observations were mad...

Background: Eye examination for screening of Retinopathy of Prematurity (ROP), as a painful procedure, causes physiological changes in premature infants. Multisensory stimulation is a non-pharmacological analgesic method which affects physiological measures during painful procedures. Aim: To determine the effect of multisensory stimulation on oxygen saturation in premature infants during eye ex...

STUDY AIM To evaluate the feasibility of combined oximetry (pulse oximetric saturation [Spo(2)]) and cutaneous capnography (transcutaneous carbon dioxide tension [Ptcco(2)]) for oxygen titration in patients requiring long-term oxygen therapy. METHODS Twenty patients with obstructive or restrictive lung disease underwent oxygen titration using a combined cutaneous oximetry-capnography sensor. ...

Oxygen extraction (OE) by all cells is dependent on an adequate supply of oxygen in proximal blood vessels and the cell's need and ability to uptake that oxygen. Here the role of blood flow in regulating OE in skin and skeletal muscle was investigated in lean and obese men. OE was derived by two optical reflectance spectroscopy techniques: 1) from the rate of fall in mean blood saturation durin...

Long-term monitoring of central haemodynamics with implanted monitoring systems might be valuable in managing heart failure patients. Such systems offer an opportunity for repeated 'semi-invasive' cardiac output determinations according to the Fick principle. Five patients, four with chronic heart failure and one with chronic pulmonary disease, underwent supine exercise testing during cardiac c...

Interest in the causes and characteristics of chronic obstructive pulmonary disease (COPD) and its clinical manifestations has grown in the last 10 years. The range of clinical symptoms and other specific characteristics of COPD patients has led it be considered more as a syndrome than a disease, and many investigators have been motivated to define new phenotypes that reflect the particular fea...