PubMed Health⌕ Search

Biomedical subjects

R Dove

Publications and source records attributed to R Dove.

7 recordsLinked to original sources
PubMed2005

Light-weight lead aprons--light on weight, protection or labelling accuracy?

X-ray transmission tests were performed on a Green-Lite (Infab Corporation) apron/vest combination, and compared to a number of other apron/vest combinations routinely used at Christchurch Hospital as well as a sheet of 0.5 mm lead. The materials were X-rayed using the primary beam of a Philips Optimus 50 X-ray machine over an energy range of 50-125 kVp. The entrance and exit doses were recorded and percentage transmission calculated for each kVp. The Green-Lite apron/vest (labelled as 0.5 mm lead at 85 kVp) relies on the overlap at the front to provide the nominal 0.5 mm protection for both the vest and the apron. It performed significantly worse than 0.5 mm of lead and other 0.5 mm lead equivalent apron/vest combinations and provided between 0.3 and 0.39 mm lead equivalent protection depending on the energy used. Vests from other manufacturers all achieved 0.5 mm lead equivalence for a single layer of vest material over the range of energies tested and so were comparable to 1.0 mm lead when doubled. Some aprons relied on a double layer of material to achieve the 0.5 mm lead equivalence (which was not always made clear on the label), while others stated their lead equivalence for a single layer. This resulted in some confusion among wearers of the aprons as to which apron was better.

Equipment Failure Analysis↗
PubMed2003

Rethinking sedation and agitation management in critical illness.

OBJECTIVE: To examine difficulties in sedation management in the critically ill patient and explore how a semi automated sedation controller can improve agitation control. To present recent work on measurements of agitation, dynamic systems modelling and control of patient agitation response. DATA SOURCES: Articles and peer-reviewed studies identified through a PUBMED search and selected original works from the biomedical engineering literature of relevance to agitation control and management. SUMMARY OF REVIEW: Over-sedation has an adverse impact on intensive care resources. Interventions to constrain sedation delivery through development of protocols or regular cessation of infusions result in reduction in resource utilisation, but have not significantly addressed existing difficulties in agitation control. We develop a paradigm in which control of agitation in critically ill patients becomes the primary objective of sedation management. This principle is central to the function of a nurse-managed semi-automated sedation delivery device. The clinical application of this device using subjective assessments of agitation is presented. A framework for the development of improved automated sedation delivery systems using objective measurements of agitation and control, based on agitation feedback, is described. Using dynamic systems modelling and a simulated nurse, a bolus-driven approach significantly reduced agitation and minimised drug utilisation. This result challenges the current practice of sedating patients using continuous infusions. CONCLUSIONS: A simple computerised interface with an algorithm that continually reduces the infusion rate in the absence of agitation has successfully been introduced into clinical practice. Nursing staff reported high levels of satisfaction with this device and it has enabled detailed data on patterns of sedation administration to be extracted for analysis. This data has been used to validate a model of the fundamental agitation-sedation dynamics.

Journal Article↗
PubMed1997

The febrile stress of routine vaccination does not increase central apnoea in normal infants.

We tested the hypothesis that the febrile stress of routine vaccination would increase central apnoea in normal infants. Twenty-one normal infants had continuous overnight breathing and temperature recorded at home, before and after 58 routine vaccination episodes. Central apnoea, of at least 5 sec duration, was detected by computer algorithm and confirmed by human inspection. The longest recorded apnoea was 16 sec (n = 1) during 3629 h of sleep. Overnight rectal temperature increased after vaccination (median 0.52 degrees C, 95% CI 0.40, 0.65). Apnoea density reduced on 46/53 vaccination nights (median -29%, 95% CI -20, -37) followed by an increase on subsequent nights (median +10%, 95% CI +1%,+21%). Overall, apnoea density was similar during the 3 nights preceding and 4 nights following vaccination (median +1%, 95% CI +9,-6). The febrile stress of routine vaccination did not increase central apnoea in normal infants.

Body Temperature↗
PubMed1996

Breathing, sleep state, and rectal temperature oscillations.

Overheating may cause terminal apnoea and cot death. Rectal temperature and breathing patterns were examined in normal infants at home during the first 6 months of life. Twenty one infants had continuous overnight rectal temperature and breathing recordings for 429 nights (mean 20.4 nights, range 7-30) spaced over the first six months of life. Periods when breathing was 'regular' were directly marked on single night records. Sleep state was determined from respiratory variables. 'Regular' breathing was a reliable marker of 'quiet' sleep (specificity 93%). The duration of 'quiet' sleep increased from 6 to 22 minutes from two weeks to three months of age and then remained static, as did the proportion of sleep spent in the quiet phase (9% to 34%). Rectal temperature fell during 66% of quiet sleep and usually rose during rapid eye movement (REM) sleep. The drop in rectal temperature was maximal at the start of quiet sleep, whereas the maximum rise during REM sleep was reached after 10 to 15 minutes. Oscillations in rectal temperature are associated with changes in sleep and breathing state. The maturation of rectal temperature patterns during the first six months of life are closely related to a maturation of sleep state and breathing patterns.

Aging↗
PubMed1990

Continuous multiple location body temperature measurement of infants.

This study was done to evaluate the most suitable location of skin temperature sensors to enable long term temperature measurements of infants. A high accuracy eight channel temperature monitor was developed. Linear semiconductor sensor probes were constructed in association with this. System accuracy and stability were tested. Preliminary clinical studies have shown considerable variation from the core temperature for all surface measurement locations.

Body Temperature↗
PubMed1990

Computer polygraphic system for infants at risk for sudden infant death syndrome (SIDS).

We have designed and developed a suite of equipment for polygraphic assessment of infants thought to be at risk for Sudden Infant Death Syndrome. A range of commercially available and custom made instrumentation is used to monitor cardio-respiratory function and thermal activity. The PC based system records continuous overnight trends and is able to detect apnoea, bradycardia, tachycardia, oxygen desaturation and other significant clinical events, producing summary data and graphs at the conclusion of the monitoring. The system is fully interactive and adaptable to various clinical and research requirements.

Computer Graphics↗