Dinamap 845

The patient's heart and blood pressure are monitored by anesthesiologists during surgery.  Blood pressure measurement by the oscillometric method was introduced in the 1870s. Biomedical engineer and entrepreneur Maynard Ramsey, III, M.D., PhD., invented his first blood pressure monitor in the 1960s, while still a medical student at Duke University. He formed his own company, Applied Medical Research (AMR) to manufacture it.  In 1976 AMR introduced the oscillometric Dinamap 825, the world's first microprocessor-based vital signs monitor.  The name is an acronym for Device for Indirect Non-invasive Mean Arterial Pressure.

The model 845 was introduced in 1978. It could be set to take automatic readings as often as once per minute for up to 16 minutes, or it could be switched to manual mode. The results of each reading remained on display until a new reading was taken. In 1979, AMR was acquired by Johnson & Johnson, which formed the Critikon division to manufacture AMR's products. Dr. Ramsey worked for Critikon for 15 years before starting another new company of his own. In 2010 the Society for Technology in Anesthesia honored Dr. Ramsey with the Gravenstein Award for his life-long contribution to blood pressure measurement.

The example shown here was donated by Drs. Susan and Jerry Dorsch.