System for distending body tissue cavities by continuous flow irrigation

A method of distending a body tissue cavity of a subject by continuous flow irrigation, said method comprising the steps of:

• (a) dispensing a low viscosity physiologic fluid from a fluid source reservoir to an inflow port through a fluid supply conduit tube, a variable speed positive displacement inflow pump and an inflow tube;
• the flow rate of the said inflow pump being termed as the inflow rate;
• (b) providing the low viscosity physiologic fluid into the body tissue cavity via an inflow port of an endoscope for distending the body tissue cavity of the subject;
• (c) removing a waste fluid from the cavity via an outlet port of an endoscope through an outflow conduit tube, a variable speed positive displacement outflow pump, a waste fluid carrying tube and a waste fluid collecting container;
• the flow rate of the said outflow pump being termed as the outflow rate;
• the said inflow rate being always greater than the outflow rate;
• and
• (d) providing a tube having a controllable constriction site between the fluid source reservoir and the inflow tube such that the tube provides a route for any excess fluid being pumped by the inflow pump to bypass the inflow pump into the fluid supply tube to maintain a constant pressure in the body tissue cavity.

A system for distending a body tissue cavity by continuous flow irrigation during endoscopic procedures, said system comprising:

• a fluid source reservoir containing a low viscosity physiologic fluid;
• a fluid supply conduit tube connecting the fluid source reservoir to an inlet port of a variable speed positive displacement inflow pump and an outlet port of the said inflow pump being connectable to an inflow port of an endoscope through an inflow tube for pumping the fluid at a controlled flow rate into the body tissue cavity, the flow rate of the said inflow pump being termed as the inflow rate;
• an outflow port of an endoscope being connectable to an inlet port of a variable speed positive displacement outflow pump through an outflow tube for removing the fluid from the body tissue cavity at a controlled flow rate, the flow rate of the said outflow pump being termed as the outflow rate;
• the said inflow rate being always greater than the outflow rate;
• an outlet port of the outflow pump being connected to a waste fluid collecting container;
• and
• a tube having a controllable constriction site provided between the fluid source reservoir and the inflow tube such that the tube by-passes the inflow pump, wherein the tube provides a route for any excess fluid pumped by the inflow pump to bypass the inflow pump into the fluid supply tube to maintain a constant cavity pressure in the body tissue cavity and without a controller operating the variable speed positive displacement inflow pump and the variable speed positive displacement outflow pump, wherein the constant cavity pressure in the body tissue cavity allows for endoscopic imaging and endoscopic visualization of the body tissue cavity walls.

A method of distending a body tissue cavity of a subject by continuous flow irrigation, said method comprising the steps of:

• (a) dispensing a low viscosity physiologic fluid from a fluid source reservoir to an inflow port through a fluid supply conduit tube, a variable speed positive displacement inflow pump and an inflow tube;
• the flow rate of the said inflow pump being termed as the inflow rate;
• (b) providing the low viscosity physiologic fluid into a body tissue cavity via an inflow port of an endoscope for distending the body tissue cavity of the subject;
• (c) removing a waste fluid from the cavity via an outlet port of an endoscope through an outflow conduit tube, a variable speed positive displacement outflow pump, a waste fluid carrying tube and a waste fluid collecting container;
• the flow rate of the said outflow pump being termed as the inflow rate;
• the said inflow rate being always greater than the outflow rate;
• (d) providing a tube having a controllable constriction site between the fluid source reservoir and the inflow tube such that the tube provides a route for any excess fluid pumped by the inflow pump to bypass the inflow pump into the fluid supply tube to maintain a constant cavity pressure in the body tissue cavity and without a controller operating the variable speed positive displacement inflow pump and the variable speed positive displacement outflow pump, wherein the constant cavity pressure in the body tissue cavity allows for endoscopic imaging and endoscopic visualization of body tissue cavity walls;
• and
• (e) performing endoscopic imaging and endoscopic visualization of the body tissue cavity walls while constant cavity pressure is maintained in the body tissue cavity.