DR-HO's Pain Therapy System 4-PADS T.E.N.S.DR HO'S Pain Therapy System is a professional TENS (Transcutaneous Electrical Nerve Stimulation) device used by Chiropractors and Physiotherapists. It was developed by Dr. Michael Ho, a Chiropractor and Acupuncturist, at his Pain and Headache Clinic in Toronto, Canada for his patients. A traditional TENS unit only blocks the pain temporarily. Traditional TENS machines provide stimulation at the same frequency, and over time the body adapts and stops