Sternal Force-Displacement Relationship During Cardiopulmonary Resuscitation
01 May 1993-Journal of Biomechanical Engineering-transactions of The Asme (American Society of Mechanical Engineers)-Vol. 115, Iss: 2, pp 195-201
TL;DR: A viscoelastic model was developed to describe the dynamic response of the human chest to cyclic loading during manual cardiopulmonary resuscitation (CPR) and consists of the parallel combination of a spring and dashpot.
Abstract: A viscoelastic model is presented to describe the dynamic response of the human chest to cyclic loading during manual cardiopulmonary resuscitation (CPR) Sternal force and displacement were measured during 16 clinical resuscitation attempts and during compressions on five CPR training manikins The model was developed to describe the clinical data and consists of the parallel combination of a spring and dashpot The human chests' elastic and damping properties were both augmented with increasing displacement The manikins' elastic properties were stiffer and both elastic and damping properties were less dependent on displacement than the humans'
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Patent•
08 Nov 1999TL;DR: In this paper, an automated controller (28) and an automated constricting device (59) were provided for applying CPR to the recipient in an automated fashion, in which a displacement detector produces a displacement indicative signal indicative of the displacement of the CPR recipient's chest toward the recipient's spine.
Abstract: Chest compressions are measured and prompted to facilitate the effective administration of CPR. A displacement detector (12) produces a displacement indicative signal indicative of the displacement of the CPR recipient"s chest toward the recipient"s spine. A signaling mechanism (18) provides chest compression indication signals directing a chest compression force being applied to the chest and a frequency of such compressions. An automated controller (28) and an automated constricting device (59) may be provided for applying CPR to the recipient in an automated fashion. The automated controller (28) receives the chest compression indication signals from the signaling mechanism (18). In accordance with the chest compression indication signals, it controls the force and frequency of constrictions. The system (10) may be provided with a tilt compensator (16) comprising a tilt sensor mechanism (24, 25) outputting a tilt compensation signal indicative of the extent of tilt of the device, and may be further provided with an adjuster (S10) for adjusting the distance value in accordance with the tilt compensation signal. An ECG signal processor may be provided which removes the CPR-induced artifact from a measured ECG signal obtained during the administration of CPR.
186 citations
TL;DR: In most out-of-hospital cardiac arrest victims adequate chest compression depth can be achieved by a force<50 kg, indicating that an average sized and fit rescuer should be able to perform effective CPR in most adult patients.
164 citations
TL;DR: In this article, the authors evaluated whether exposure to infant siblings in early life is associated with the risk of MS, and explored the possible mechanism for any apparent beneficial effect, including altered EBV infection patterns.
Abstract: ContextThe “hygiene hypothesis” has implicated sibship as a marker
of infection load during early life and suggests that exposure or reexposure
to infections can influence the developing immune system. Viral infection
has also been implicated in the pathogenesis of multiple sclerosis (MS).ObjectivesTo evaluate whether exposure to infant siblings in early life is associated
with the risk of MS, and to explore the possible mechanism for any apparent
protective effect, including altered Epstein-Barr virus (EBV) infection patterns.Design, Setting, and PatientsPopulation-based case-control study in Tasmania, Australia, from 1999
to 2001 based on 136 cases of magnetic resonance imaging–confirmed MS
and 272 community controls, matched on sex and year of birth.Main Outcome MeasureRisk of MS by duration of contact with younger siblings aged less than
2 years in the first 6 years of life.ResultsIncreasing duration of contact with a younger sibling aged less than
2 years in the first 6 years of life was associated with reduced MS risk (adjusted
odds ratios [AORs]: <1 infant-year, 1.00 [reference]; 1 to <3 infant-years,
0.57 [95% confidence interval {CI}, 0.33-0.98]; 3 to <5 infant-years, 0.40
[95% CI, 0.19-0.92]; ≥5 infant-years, 0.12 [95% CI, 0.02-0.88]; test for
trend, P = .002). A history of exposure
to infant siblings was associated with a reduced IgG response to EBV among
controls. Controls with at least 1 infant-year contact had a reduced risk
of infectious mononucleosis and a reduced risk of very high composite EBV
IgG titers (AOR, 0.33; 95% CI, 0.11-0.98) compared with other controls. The
inverse association between higher infant contact and MS was independent of
EBV IgG titer.ConclusionHigher infant sibling exposure in the first 6 years of life was associated
with a reduced risk of MS, possibly by altering childhood infection patterns
and related immune responses.
156 citations
Journal Article•
TL;DR: Higher infant sibling exposure in the first 6 years of life was associated with a reduced risk of MS, possibly by altering childhood infection patterns and related immune responses.
109 citations
TL;DR: Ambulance personnel were physically capable of consistently compressing to the Guidelines depth even on the stiffest chest, which strongly indicate that the inadequate chest compressions found in the clinical study were not due to lack of physical capability.
58 citations