Paul Grayson, 51, admitted sexual assault, voyeurism and other charges at Sheffield Magistrates’ Court on Friday, but denied other charges alleging he made indecent images of children.
Police have said many of the offences were committed in the Day Case Theatre Unit at Sheffield’s Royal Hallamshire Hospital, against both staff and patients, between 2017 and 2020.
Some of charges relate to the discovery of recordings of the intimate areas of three unidentified female patients, a police spokesman said when Grayson was charged in December.
District Judge Tim Spruce sent the case to Sheffield Crown Court, where Grayson will face trial on the charges of making indecent images of children.
Grayson, of Woodstock Road, Sheffield, admitted 13 voyeurism charges, including one created by new upskirting legislation.
He also pleaded guilty to two counts of sexual assault, one of sexual touching and one of taking an indecent image of a 17-year-old child.
He denied three counts of making indecent images of children – relating to 123 stills and three videos across categories A, B and C.
Grayson, who is bald with a grey beard, sat in Court Two’s large dock wearing a dark waterproof coat over a grey shirt and dark tie.
He was bailed by Mr Spruce to appear at Sheffield Crown Court on March 7.
His bail conditions include staying away from the Royal Hallamshire Hospital except for bona fide appointments and in emergencies.
When Grayson was charged last year, Chief Superintendent Shelley Hemsley, district commander for Sheffield, said: “I know this case is extremely unsettling. These charges follow an extensive investigation carried out by officers in our Protecting Vulnerable People department.
“Despite significant and wide-ranging enquiries by the team, who have worked closely with the Sheffield Teaching Hospitals NHS Foundation Trust, it is highly unlikely that the three unidentified women will ever be identified as all existing lines of enquiry have now been exhausted.
“Despite this, we have pursued charges on behalf of these women so that the judicial process can continue.”
The hospital’s chief nurse, Professor Chris Morley, said in December the trust was co-operating with police and taking the allegations “extremely seriously”.
He said he was sorry the three women could not be identified.