title: Neonatal head and torso vibration exposure during inter-hospital transfer.
abstract: Inter-hospital transport of premature infants is increasingly common, given the centralisation of neonatal intensive care. However, it is known to be associated with anomalously increased morbidity, most notably brain injury, and with increased mortality from multifactorial causes. Surprisingly, there have been relatively few previous studies investigating the levels of mechanical shock and vibration hazard present during this vehicular transport pathway. Using a custom inertial datalogger, and analysis software, we quantify vibration and linear head acceleration. Mounting multiple inertial sensing units on the forehead and torso of neonatal patients and a preterm manikin, and on the chassis of transport incubators over the duration of inter-site transfers, we find that the resonant frequency of the mattress and harness system currently used to secure neonates inside incubators is [Formula: see text]. This couples to vehicle chassis vibration, increasing vibration exposure to the neonate. The vibration exposure per journey (A(8) using the ISO 2631 standard) was at least 20% of the action point value of current European Union regulations over all 12 neonatal transports studied, reaching 70% in two cases. Direct injury risk from linear head acceleration (HIC15) was negligible. Although the overall hazard was similar, vibration isolation differed substantially between sponge and air mattresses, with a manikin. Using a Global Positioning System datalogger alongside inertial sensors, vibration increased with vehicle speed only above 60 km/h. These preliminary findings suggest there is scope to engineer better systems for transferring sick infants, thus potentially improving their outcomes.
authors.affiliation: 1 Bioengineering Research Group, Faculty of Engineering, The University of Nottingham, Nottingham, UK.
authors.forename: Laurence
authors.initials: L
authors.lastname: Blaxter
authors.affiliation: 2 Academic Child Health, School of Medicine, University Hospital, The University of Nottingham, Nottingham, UK.
authors.forename: Mildrid
authors.initials: M
authors.lastname: Yeo
authors.affiliation: 1 Bioengineering Research Group, Faculty of Engineering, The University of Nottingham, Nottingham, UK.
authors.forename: Donal
authors.initials: D
authors.lastname: McNally
authors.affiliation: 1 Bioengineering Research Group, Faculty of Engineering, The University of Nottingham, Nottingham, UK.
authors.forename: John
authors.initials: J
authors.lastname: Crowe
authors.affiliation: 2 Academic Child Health, School of Medicine, University Hospital, The University of Nottingham, Nottingham, UK.
authors.forename: Caroline
authors.initials: C
authors.lastname: Henry
authors.affiliation: 2 Academic Child Health, School of Medicine, University Hospital, The University of Nottingham, Nottingham, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Hill
authors.affiliation: 3 Dyson School of Design Engineering, Imperial College London, London, UK.
authors.forename: Neil
authors.initials: N
authors.lastname: Mansfield
authors.affiliation: 4 CenTre Neonatal Transport Service, University Hospitals of Leicester NHS Trust, Leicester, UK.|5 CenTre Neonatal Transport Service, Nottingham University Hospitals NHS Trust, Nottingham, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Leslie
authors.affiliation: 2 Academic Child Health, School of Medicine, University Hospital, The University of Nottingham, Nottingham, UK.|4 CenTre Neonatal Transport Service, University Hospitals of Leicester NHS Trust, Leicester, UK.|5 CenTre Neonatal Transport Service, Nottingham University Hospitals NHS Trust, Nottingham, UK.
authors.forename: Don
authors.initials: D
authors.lastname: Sharkey
mesh_terms: D000054:Acceleration / Q000009:adverse effects; D000552:Ambulances; D001696:Biomechanical Phenomena; D006259:Craniocerebral Trauma / Q000209:etiology / Q000517:prevention & control; D006257:Head; D006801:Humans; D007231:Infant, Newborn; D008348:Manikins; D014187:Transportation of Patients; D014732:Vibration / Q000009:adverse effects*
keywords: Vibration hazard; brain injury; intraventricular haemorrhage; linear head acceleration; monitoring; neonatal; shock hazard