Journal of medical engineering & technology
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An abnormal respiratory rate is often the earliest sign of critical illness. A reliable estimate of respiratory rate is vital in the application of remote telemonitoring systems, which may facilitate early supported discharge from hospital or prompt recognition of physiological deterioration in high-risk patient groups. ⋯ Analysis of the photoplethysmogram (PPG) waveform offers an alternative means of non-invasive respiratory rate monitoring, but further development is required to enable reliable estimates. This review conceptualizes the challenge by discussing the effect of respiration on the PPG waveform and the key physiological mechanisms that underpin the derivation of respiratory rate from the PPG.
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We have designed, built and tested a novel spinal cord surrogate that mimics the low-amplitude cardiac-driven pulsations of the human spinal cord, for use in developing intradural implants to be used in a novel form of neuromodulation for the treatment of intractable pain and motor system dysfunction. The silicone surrogate has an oval cross section, 10 mm major axis × 6 mm minor axis, and incorporates a 3 mm diameter × 3 cm long angioplasty balloon that serves as the pulsation actuator. When pneumatically driven at 1 Hz and 1.5 atmospheres (≈ 1140 mm Hg), the surrogate's diametric pulsation is ≈ 100 μm, which corresponds well to in vivo observations. The applications for this surrogate are presented and discussed.
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In the mountain climbing community, conventional prevention of altitude mountain sickness (AMS) relies primarily on a formal acclimatization period. AMS symptoms during mountaineering climbs are managed with medication, oxygen and minor recompression (1524-2438 m altitude) using a portable chamber, such as the Gamow Bag. This is not always an acceptable therapy alternative in a predominantly elderly tourist population. ⋯ This approach encompasses traditional and advanced medical interventions including the use of a clinical HBO(2) chamber capable of recompression to three times greater than sea level pressure (3 atmosphere absolute (ATA)). The system uses a series of AMS hyperbaric treatment profiles that LST has previously developed to the US military and NASA, and that take greater advantage of vasoconstrictive effects of oxygen under true hyperbaric conditions of 1.25 ATA. These profiles virtually eliminate AMS rebound after the initial treatment often seen in conventional AMS treatment, where the patient is either treated at altitude, or does not recompress back to sea level or greater pressure (1.25 ATA), but returns directly to the same altitude where AMS symptoms first manifested.
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Review Comparative Study
MR-compatible pumps versus manual titration of propofol for pediatric sedation.
This study aimed to review the use of two methods of propofol infusion: a metred burette system where propofol is diluted in Lactated Ringer using the rule of six [ 1 ] or an infusion pump: Medrad Continuum Magnetic resonance (MR) compatible Infusion System (Medrad Inc. Indianola, PA) and to determine the difference, if any, between the total amount of drug delivered, the impact on vital signs, sedation status and discharge time of the patients. With Institutional Review Board (IRB) approval, 140 children aged 0 to 18 years, American Society of Anesthesiologists (ASA) physical status I or II requiring sedation for elective outpatient brain Magnetic Resonance Imaging (MRI) examination were included in the study. ⋯ This study demonstrates that both infusion techniques preserve haemodynamic stability and are associated with minimal complications. The use of an infusion pump, which consistently maintains accurate dosing, reduces the amount of propofol judged adequate by the anaesthesiologist to achieve sedation in MRI. This leads to a more consistently faster emergence and early discharge after sedation in children undergoing MRI studies.
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Comparative Study
Contactless respiratory and heart rate monitoring: validation of an innovative tool.
To assess the accuracy of the EverOn™ piezoelectric sensor based contactless heart rate and respiration rate monitoring system. ⋯ The system described was found to be accurate in accordance with regulatory and industry criteria.