Irrigation system for a surgical site

A system for providing irrigation fluid from a source to a surgical site through a small incision or a natural orifice of the body, the system comprising:

• a control unit having a microprocessor and a motor under the control of said microprocessor and user input controls operatively connected to the microprocessor;
• a cassette mountable on said control unit, said cassette comprising:
• a housing defining a flow passageway, said flow passageway having an inlet for connection to said source of fluid and an outlet for providing fluid to the surgical site;
• and
• a pump located in said housing and driven by said motor, said pump having reduced efficiency when presented with back pressure to thereby limit to a safe level an amount of pressure that can be delivered to the surgical site;
• and
• a first sensor for sensing the flow of fluid in said passageway downstream from said pump, said first sensor providing an output to said microprocessor.

An irrigation system for providing fluid from a source to a surgical site in the body through a small incision or natural orifice, the system comprising:

• a disposable cassette having a fluid flow passage therethrough with an input on an upstream side for connection to the source and an output on a downstream side for providing fluid to the surgical site;
• an impeller located in said fluid flow passage;
• a reusable control unit upon which said disposable cassette can be mounted, said control unit having:
• a motor having an output shaft to which said impeller can be engaged;
• a first sensor for sensing fluid speed in said fluid flow passage downstream of said impeller;
• a second sensor for sensing pressure in said fluid flow passage downstream of said impeller;
• and
• a controller connected to said motor, said first sensor, and said second sensor adapted to control delivery of fluid to the surgical site from the source of fluid based upon input by an operator and input from the sensors.

A disposable cassette for use with a control unit for providing fluid from a source of irrigation fluid to a surgical site, said disposable cassette comprising:

• a housing releasably mountable to said control unit, said housing having an input from the source of irrigation fluid and an output to the surgical site, said housing defining a fluid flow passage between the input and the output;
• a pump located in said housing and driven by said motor, said pump having limited efficiency when presented with back pressure to thereby limit to a safe level an amount of pressure that the pump can deliver to the surgical site;
• and
• a flow indicator operatively associated with said fluid flow passage downstream of said pump, said flow indicator providing an output to said control unit,
• whereby an actual flow rate of fluid downstream of said pump toward the surgical site can be determined.

A disposable cassette for use with a control unit for providing fluid from a source of irrigation fluid to a surgical site, said disposable cassette comprising:

• a housing releasably mountable to said control unit, said housing having an input and an output to the surgical site, and further in which said housing defines a fluid flow passage between the input and the output to the surgical site;
• an impeller located in said fluid flow passage, said impeller being driven by a motor in said control unit;
• and
• a flow indicator operatively associated with said fluid flow passage downstream of said impeller, said flow indicator providing an output to said control unit, whereby an actual flow rate of fluid downstream of said impeller toward said surgical site can be determined.

A disposable cassette for use with a control unit for providing fluid from a source of irrigation fluid to a surgical site, said disposable cassette comprising:

• a housing releasably mountable to said control unit, said housing having an input from the source of irrigation fluid and an output to the surgical site and defining a fluid flow passage between the input and the output;
• an impeller located in said fluid flow passage, said impeller being driven by a motor in said control unit;
• a pressure sensitive area associated with said fluid flow passage downstream of said impeller, said pressure sensitive area providing an output to said control unit,
• whereby a measure of pressure of fluid downstream of said impeller toward said surgical site can be determined.

A method of irrigating a surgical site, comprising the steps of:

• mounting a disposable cassette on a control unit;
• attaching a source of irrigation fluid to an input of the cassette;
• delivering fluid to the surgical site from an output of the cassette;
• operating an impeller located in a passageway of the cassette by means of a motor located in the control unit;
• sensing pressure and flow in the cassette downstream from said impeller;
• and
• adjusting the operation of the motor and thereby the impeller based upon the pressure and flow sensed.

A method of irrigating a surgical site, comprising the steps of:

• mounting a disposable cassette on a control unit;
• attaching a source of irrigation fluid to an input of the cassette;
• delivering fluid to the surgical site from an output of the cassette;
• operating an impeller located in a passageway of the cassette by means of a motor located in the control unit;
• sensing pressure in the cassette downstream from said impeller;
• and
• adjusting the operation of the motor and thereby the impeller based upon the pressure sensed.