Patent ID: 8512283

Claim:
A system for distending body tissue cavities of subjects by continuous flow irrigation during endoscopic procedures, the system comprising: a collapsible fluid source reservoir containing a non viscous physiologic liquid, said fluid source reservoir being encircled by a bladder cavity, said bladder cavity being connected to an inflow pneumatic positive displacement pump through an air transporting tube, an auxiliary tube having a fixed constriction site coupled to a wall of the air transporting tube disposed between the positive displacement inflow pump and the bladder cavity, a free end of the auxiliary tube opening directly into the atmosphere, the constriction site having a fixed diameter, wherein the auxiliary tube provides a route for air pumped by the positive displacement pump to escape to the atmosphere; a fluid supply inflow tube connecting the fluid source reservoir to an inflow port for pumping the fluid at a controlled flow rate into the body tissue cavity, the flow rate of the inflow pump being termed as the inflow rate and the rate at which the fluid from the inflow tube enters into the tissue cavity being termed as the cavity inflow rate; an inflow liquid pressure transducer connected between the fluid source reservoir and the inflow port, the pressure transducer comprising a pressure transducer tube extending from the fluid supply inflow tube, wherein the pressure transducer measures the fluid pressure via a column of liquid or air present in the lumen of the pressure transducer tube; and an outflow port connectable to an inlet end of a variable speed positive displacement outflow pump through an outflow tube for removing the fluid from the cavity at a controlled flow rate, the flow rate of the outflow pump being termed as the cavity outflow rate, an outlet end of the outflow pump being connected to a waste fluid collecting container, wherein the air transporting tube allows a constant cavity pressure in the body tissue cavity and distends the body tissue cavity by continuous flow irrigation during an endoscopic procedure while the inflow positive displacement pump and the outflow positive displacement pump run simultaneously and regardless of the cavity outflow rate, and wherein the air transporting auxiliary tube is releasably provided between the positive displacement pump and the bladder cavity to enable replacement of the tube with another tube having a different diameter at the constriction site to suit the operational need of the endoscopic procedure.