Martyn Smith attacked Michael Hipgrave, who lives in Telford, and Deena Evans at his house in Stephens Close, Ashmore Park, Wolverhampton, on July 6 last year.
The pair had featured together in a Christmas special of Inside the Ambulance in 2019.
At a previous hearing, Smith, 52, had denied two counts of wounding with intent – but at a pre-trial review hearing at Wolverhampton Crown Court today he changed his pleas to guilty to both charges.
Smith will be sentenced in June. The previous hearing was told Smith claimed he believed the paramedics were burglars.
Judge Rhona Campbell told him: "I cannot sentence you today as I need to know more about you. I'm aware there have been some difficulties with your mental health in the past and I want to find out more about that before I sentence you.
"I will adjourn until June 14 for a psychologist to write a report about you. I will remand you in custody until then."
Ms Evans and Mr Hipgrave had attended Smith's home last summer with a police officer to carry out a welfare check when the incident unfolded.
Ms Evans suffered a chest wound and nerve damage and fellow medic Mr Hipgrave sustained a back injury while they were carrying out a concern-for-welfare check.
Mr Hipgrave was discharged from hospital later the same evening, while Ms Evans had to spend another two days receiving treatment.
In October last year, Ms Evans returned for her first shift back with West Midlands Ambulance Service. At the time, she said: "My recovery is going well. I’m still receiving physio and counselling but it’s helping. I still have numbness in my arm but it so far hasn’t affected my job.
"My first day I was really nervous, I felt sick and felt like I couldn’t breathe but all the staff at Willenhall helped me, and my crew mate always makes me laugh so it was a good shift.
“The public support has been phenomenal, it really has been overwhelming. It certainly brings back faith in humanity, and I’m glad to be back doing my job.”
Mr Hipgrave has also returned to work.
More than £4,000 was raised for the two paramedics through a JustGiving page at the time.
The pair had also featured together in a Christmas special of Inside the Ambulance in 2019 screened on W, a UKTV channel. The show followed West Midlands Ambulance Service crews as they attended call-outs.
Smith was remanded in custody until his sentencing hearing on Monday, June 14.