The Jarvik 2000 pump is monitored and its output adjusted by each patient according to his or her circumstances and needs. We believe that manual control remains the most sensible approach to regulating the operation of VADs. While faulty calculations or bad sensor data can wreak havoc on a microprocessor-controlled system, an educated patient provides highly responsive, adaptable and safe control system unmatched by computers. Manual control also gives patients and doctors more leeway to respond to changing circumstances.
Manual control, however, requires a user-friendly control interface. The Jarvik 2000's external controller is designed with ease of use in mind. Using a dial numbered from 1 to 5, the patient manually adjusts the rate at which the Jarvik 2000 pumps blood to suit his or her level of activity — turning it up when exercising and down to go to sleep. The range of speeds offered by the controller is broad enough to give the patient flexibility in choosing and accommodating different activities, but narrow enough to prevent unsafe extremes. Patients and their caretakers are provided with guidelines for making adjustments to pump speed, and they quickly become comfortable doing so.