Continuous tape-recording of ambulatory blood pressure. Technical considerations

A technique of recording continuous intra-arterial blood pressure in fully ambulatory subjects, on to magnetic tape is described. This method makes use of a specially developed transducer-perfusion unit, which incorporates a strain-gauge pressure transducer and a perfusion system using an electrical "delta" pump. The signal is recorded on cassette tape using a miniature physiological recorder. This recording method has been fully evaluated in the laboratory and has been used clinically on 550 occasions with satisfactory results. Technical limitations and clinical experience of this recording technique are discussed.