1 Department of Bioengineering, Paediatric Blast Injury Partnership, Imperial College London, London SW7 2AZ, UK. Electronic address: e.mayhew@imperial.ac.uk.
2 Department of Bioengineering, Paediatric Blast Injury Partnership, Imperial College London, London SW7 2AZ, UK.
3 Bristol Royal Hospital for Children, University Hospitals Bristol, Bristol, UK.