[1] Department of Urology and Andrology,
[2] Umeå University,undefined
[3] S-901 85 Umeå,undefined
[4] Sweden Tel.: 46 90 785 00 00; Fax: 46 90 12 53 96,undefined
[5] Department of Biomedical Engineering,undefined
[6] Huddinge University Hospital,undefined
[7] Stockholm,undefined
[8] Sweden,undefined