[1] St James Hosp, Dept Med Phys & Bioengn, Dublin 8, Ireland
[2] St James Hosp, Mercers Inst Successful Ageing, Dublin 8, Ireland
[3] Univ Dublin Trinity Coll, Sch Med Gerontol, Dublin 2, Ireland
[4] Univ Dublin Trinity Coll, Sch Engn, Trinity Ctr Bioengn, Dublin 2, Ireland