PubMed Health⌕ Search

Biomedical subjects

J S Lundsgaard

Publications and source records attributed to J S Lundsgaard.

10 recordsLinked to original sources
PubMed1981

Transcutaneous measurement of arterialized capillary blood PCO2 by a new mass spectrometer inlet system.

A new mass spectrometer inlet system for transcutaneous measurement of capillary blood PCO2 is described. The system is constructed to allow calibration in a gas mixture of known composition. The accuracy and precision of the system is demonstrated in human experiments, in which the PCO2 measured by the new probe is shown to be highly correlated with arterialized capillary PCO2 measured by Astrup's equilibration technique.

Adult↗
PubMed1980

Fast-responding flow-independent blood gas catheter for oxygen measurement.

Analytic expressions were derived for the response time, flow dependency, and signal-to-background ratio of blood gas catheters. These expressions were utilized to optimize the design of a new catheter. The catheter was tested in vitro and in vivo, and shown to be fast responding and practically flow independent, with an acceptable signal-to-background ratio.

Animals↗
PubMed1978

In vivo calibration of flow-dependent blood gas catheters.

In vivo calibration of blood gas catheters is complicated by the fact that their signals are flow dependent. A calibration method is described here, which permits continuous in vivo calibration. The principle is to compensate for flow dependence through simultaneous measurement on an inspired, inert reference gas of known partial pressure. The method is demonstrated by experiments on three anesthetized dogs, in which the arterial oxygen partial pressure was measured in situ with a flow-dependent blood gas catheter. The compensated signal was in good agreement with the partial pressure of oxygen measured with conventional techniques.

Animals↗
PubMed1977

High precision mixing of anesthetic gases based on a new principle.

A machine has been constructed for mixing O2 and N2O. It consists of: (a) a proportional pressure and thereby flow regulator at the inlets for O2 and N2O; (b) a digital gas mixer which determines the gas mixture; and (c) a rotameter to measure the outlet flow. The contents of mixtures obtained from the machine were measured with a quadropole mass spectrometer (at 2 and 5 1 min--1 with downstream pressures of 500 and 3000 Pa). The mean numeric difference between desired and registered vol% O2 varied between 0.3 and 0.5 vol% at the four conditions tested. The maximal deviation was 1.2 vol%. Five conventional machines in daily use at the hospital were also tested. The mean numeric difference for these machines varied between 1.1 and 2.7 vol% O2. The maximum deviation was 7.4 vol%.

Anesthesia, Inhalation↗