Journal of clinical monitoring and computing
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J Clin Monit Comput · Jul 1999
High fidelity correction of pressure signals from fluid-filled systems by harmonic analysis.
Fluid-filled systems are generally used for invasive pressure measurements in cardiology, anesthesiology and intensive care medicine. Wave reflection and attenuation cause considerable signal distortion. ⋯ High fidelity correction of pressure signals from fluid-filled systems by harmonic analysis is feasible.
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J Clin Monit Comput · Jul 1999
Nonlinear model-based predictive control of non-depolarizing muscle relaxants using neural networks.
Neuromuscular blockade can be relatively easily measured in the clinical setting. Consequently, closed-loop control can be exercised by measuring the neuromuscular activity, calculating the dose of drug necessary to achieve a predefined degree of neuromuscular blockade and finally directing an infusion pump. Recently introduced short-acting blocking agents like mivacurium provide benefits for the clinical routine due to a small onset time and half life. ⋯ In a clinical study the EMG module within a Datex AS/3 monitor was used to measure the blockade and a Grasepy 3500 infusion pump for i.v. administration of mivacurium to 35 patients (ASA I-III). The performance of the novel system (mean of the T1 error: -0.32 +/- 1.7) compares favourably with closed-loop controllers demonstrated in the past. These promising results and the easy adaption to other blocking agents encourage to apply this technology even for delivering hypnotic drugs.
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J Clin Monit Comput · Jul 1999
Increase in twitch force of the adductor pollicis muscle with stabilized preload at constant thumb abduction before and after administration of muscle relaxant.
To determine whether the twitch force of the adductor pollicis remains stable when 0.1 Hz single twitch stimulation is started after stabilization of the thumb preload at a constant degree of thumb abduction; also to study any possible increase in twitch force before the onset of and after the recovery from neuromuscular block. ⋯ Twitch forces may increase when stimulation is started after stabilization of thumb preload at a constant degree of thumb abduction. In some patients twitch forces may increase before the onset of neuromuscular block with vecuronium or d-tubocurarine; twitch forces increase after recovery from suxamethonium.
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Inhaled nitric oxide (NO) was found to cause selective pulmonary vasodilation in the late 1980's and since then there has been a huge interest in studying its clinical benefits. The equipment used to deliver and monitor inhaled NO has gone through a dramatic evolution from simple flow meters and industrial monitors to to-days purpose built, fully integrated, NO delivery and monitoring systems that were designed specifically for the demanding area of the intensive care unit. This paper explores the evolution of inhaled NO delivery systems and identifies the design challenges, the safety and regulatory requirements and the ease of use issues that had to be solved to bring this new exciting new class of medical device in to clinical use.