Abstract: An air management system is described for removing and reintroducing a desired amount of air into an air passage of a pressure measurement catheter. More specifically, the system includes a cylindrical housing, check valves in communication with the housing and an moveable shaft with multiple sealing members along its length. As the shaft is moved within the housing, a piston member causes the residual air in the catheter air passage to be evacuated to a defined negative pressure. Further movement of the shaft causes a piston member to inject a predetermined volume of air into the catheter air passage. In this respect, periodic adjustments of the piston member returns the volume of air in a variable volume chamber to one that is unaffected by residual volume in the chamber and that provides an optimum volume of air to maximize the time the sensor can function accurately between recharging events.

Abstract: An air management system is described for removing and reintroducing a desired amount of air into an air passage of a pressure measurement catheter. More specifically, the system includes a cylindrical housing, check valves in communication with the housing and an moveable shaft with multiple sealing members along its length. As the shaft is moved within the housing, a piston member causes the residual air in the catheter air passage to be evacuated to a defined negative pressure. Further movement of the shaft causes a piston member to inject a predetermined volume of air into the catheter air passage. In this respect, periodic adjustments of the piston member returns the volume of air in a variable volume chamber to one that is unaffected by residual volume in the chamber and that provides an optimum volume of air to maximize the time the sensor can function accurately between recharging events.

Abstract: An outflow line is connected to an infusion pump that is programmed to run at a fixed rate. The outflow line has a bypass line that leads from the pump outlet back to the pump inlet. A line downstream of the entrance to the bypass line leads to the patient. The system has two valves. The fluid en route to the patient passes through the first valve. The bypass line passes through the second valve. When one valve is open, the other is closed. The valves' flow states are controlled by a signal from a control instrument. The system allows the pump output to be directed to the patient or to a bypass circuit that returns fluid leaving the pump back to the pump inlet. The system makes it possible to vary the amount of fluid delivered to a patient by an infusion pump set at a constant pumping rate by varying the open and closed state of valves in response to a signal from a patient monitoring instrument.

Abstract: An improved blood pressure monitoring pad assembly and its method of use are disclosed herein. In accordance with a first feature of the pad assembly a release mechanism is used to prevent the pad assembly from detaching from the skin as the bladder is pressurized. In accordance with a second feature, the pad assembly includes a flexible cover movably connected with a flexible base assembly. In accordance with a third feature, the pad assembly incorporates a biflex member.

Abstract: A gas-column pressure measuring catheter which is insertable into a mammalian body for purposes of transmitting pressure changes from a location within the mammalian body to a pressure sensor which is either incorporated into, or connected to, the catheter. In a preferred embodiment, the gas-column pressure measuring catheter comprises an elongate catheter body having a gas-filled lumen extending longitudinally therethrough, and a gas-filled membrane-walled chamber positioned on the catheter body in communication with the gas-filled lumen such that pressure changes exerted against the outer surface of the membrane-walled chamber will result in the transmission of pressure changes through the gas-filled catheter lumen. The gas-filled membrane-walled chamber may be located on the side wall of the catheter body, or may be located on the distal end of the catheter body.