Abstract: A pneumatic tourniquet for maintaining occluded or restricted blood flow into a patient's limb includes an inflatable cuff, a pressurizing mechanism for pressurizing the cuff, a pressure relief mechanism for depressurizing the cuff, a blook pressure sensing mechanism for sensing the patient's systolic blood pressure and for producing a blood pressure output signal representative thereof, and a pressure regulator mechanism responsive to the blood pressure output signal for selectably activating the pressurizing mechanism and the pressure relief mechanism to maintain a substantially constant pressure difference between the cuff pressure and the patient's systolic blood pressure.Thus, the cuff pressure may be varied "adaptively" in response to changes in the patient's intra-operative systolic blood pressure to pressurize the cuff close to the minimum level required to maintain a bloodless surgical field, thereby minimizing the risk of patient injury due to over-pressurization of the cuff.

Abstract: A pneumatic tourniquet includes an inflatable cuff, a pressurizing mechanism for pressurizing the cuff, a pressure relief mechanism for depressurizing the cuff, a pressure sensing mechanism for sensing the pressure to which the cuff is pressurized and a pressure regulator mechanism for selectably activating the pressurizing mechanism and the pressure relief means to maintain the cuff pressure near a selected pressure. Visual and audible alarm signals are triggered if the cuff pressure exceeds a cuff pressurization limit, if the cuff pressure falls below a cuff depressurization limit, or if the cuff has remained pressurized for, or in excess of a selected time period.A computer may be used to sense the cuff pressure and pressurized or depressurized the cuff as required to maintain the cuff pressure within upper and lower cuff pressure limits.