Abstract: A pressure infusion device for medical applications for applying pressure to a sealed bag of liquid, such as an I.V. bag, in which the pressure gauge is fastened directly in the pressure applying bag which presses against the I.V. bag. The gauge has a movable plunger which moves outwardly from the bag by an amount depending upon the pressure within the bag. The pressure infusion arrangement is designed to be relatively inexpensive so that it can be discarded after being used. There are two forms, one in which the I.V. bag is held against the pressure applying bag by a mesh which is secured to a fabric to form a pocket for the I.V. bag and the pressure applying bag. In the other form, the mesh is secured directly to the edge of the pressure applying bag.

Abstract: A flow regulator for use in medical apparatus for adjusting the flow of fluid in which there is a valve body with a valve member having a helical flow passage through which the fluid must flow. In order to facilitate quick adjustment of the fluid, the pitch and depth of the groove both progressively change from one end of the flow regulating device to the other, the depth of the groove becoming less as the pitch of the groove becomes finer. The valve member is longitudinally movable with respect to the valve body, and provision is made for adjusting the longitudinal position either by rotation of a threaded valve stem or by longitudinal movement of the valve stem to quickly adjust the flow rate. The helical groove may be either rectangular in cross-section, or V-shaped in cross-section. Suitable means are provided for sealing against leakage through the valve adjusting means.

Abstract: A flow regulator for use in medical apparatus for quickly adjusting the flow of fluid in which there are coacting male and female threads for adjusting the position of the flow regulating device, a female threaded portion being yieldable. The position of the flow regulating device can be rapidly changed in either direction by exerting pressure on the valve stem to force the yieldable threaded portion outwardly to enable the threads of the male portion to pass over the threads of the female portion. The portion of the flow regulating device can be adjusted more precisely by turning the valve stem in the conventional manner to cause forward or reverse movement of the flow regulating device. The yieldable female threaded portion can either be integral with the main valve body but yieldable with respect thereto, or the yieldable portion may be a separate member yieldably secured to the main valve body by a spring clip or by an elastic band.

Abstract: The open end of a catheter is inserted in the blood vessel of a patient. The catheter is connected by hollow tubing to a physiologic pressure transducer. The tube is filled with an intermediate pressure-transmitting fluid such as a physiologic saline solution. An infusion device between the patient and the transducer constantly flushes the system with a slow flow of fluid. Blood pressure variations are transmitted through the fluid to the transducer, which converts the pressure to electronic information and transmits the information to a monitor for display. Between the infusion device and the transducer is a variable restrictor which damps the pressure waves in the fluid. This restrictor is used to tune the system to eliminate resonant waves, which distort the monitoring reading. In one form, the variable restrictor includes a valve having an orifice, the effective size of which is reduced or enlarged by compressing and releasing a deformable, flexible ring.