DEVICE FOR INTRAVENOUS INJECTION OF LIQUID Russian patent published in 1996 - IPC

FIELD: medical equipment. SUBSTANCE: device for intravenous injection of liquid has flexible actuating member with liquid and installed for interaction with pneumohydraulic drive including high-and low-pressure cavities separated by the first and second movable members of closed hydraulic cavity; regulating appliance located in hydraulic cavity and hinged to turning handle; and gas pressure stabilizer. Pneumohydraulic drive has roller pump, pneumatic supply line, partition of pneumohydraulic cavity and pneumatic switch located in low-pressure cavity. In this case, the first movable member is made in form of nonrigid membrane and located on the side of high-pressure cavity communicated with internal cavity of pneumatic switch. The second movable member is made in form of working membrane with rigid center and located on the side of low-pressure cavity. Working membrane is loaded with compression spring installed for transmission of force through membrane with rigid center to hydraulic cavity. Membrane rigid center is connected with the device body by means of lever four-link mechanism. Roller pump shaft is located in low-pressure cavity square to the plane of lever four-link mechanism. Secured to lever four-link mechanism are two hubs of two overrunning clutches whose wedges are directed to one side, and two holders of overrunning clutches are supported in bearings on the shaft and made with hinges located on opposite sides from pump shaft on external side of holders which are connected by means of two connecting rods with rigid center. Pneumatic switch is made in form of shutoff member installed in air-tight body between two coaxial seats. Shutoff member is attached to arm which is installed for mechanical interaction with common rigid center of two membranes built in air-tight body. Common rigid center is loaded with compression springs from each member external side relative to air-tight body. Compression springs are encompassed by fork secured to rigid center of working membrane, and shutoff member is provided with two similar tension springs located in the plane square to seats axis in the neutral position of the shutoff member and fastened in air-tight body. In this case, axis of arm turning of shutoff member is located between shutoff member and point of attachment of tension springs. Besides, one of seats of pneumatic switch is connected through pressure stabilizer located in low-pressure cavity with pneumatic supply line, and the other seat is connected with low-pressure cavity. Regulating device is made in form of turning disk which has arched port. Partition of hydraulic cavity has arched slot for full or partial communication with port of turning disk. Actuating member is made in form of flexible main pipe of device for transfusion system. Main pipe of device for transfusion system is laid in roller pump. EFFECT: higher efficiency. 3 cl, 7 dwg