Control for surgical fluid management pump system

Patent metadata

Field	Value
Publication number	US-9289110-B2
Application number	US-201313782660-A
Country	US
Kind code	B2
Filing date	Mar 1, 2013
Priority date	Apr 5, 2012
Publication date	Mar 22, 2016
Grant date	Mar 22, 2016

Abstract

A surgical pump system arrangement receives an inflow cassette and provides fluid flow to a surgical site in a joint of a patient. The arrangement calculates load coefficients for a pressure loss curve based on an identified inflow cannula and an identified endoscope utilized therewith. The arrangement determines if the cannula is disposed at a surgical site and if adequate fluid flow is provided. Further, the arrangement determines if the inflow cannula and endoscope are properly identified. The arrangement integrates with an identified or unidentified surgical device to adjust pump operation when the surgical device is operating. The arrangement maps actuators disposed on a surgical handpiece or footswitch to control operation of the pump system, including providing suction to an outflow path of a surgical device that is not operating. The arrangement also determines when an inflow pump cassette is not properly inserted into the pump.

First claim

We claim:

1. A method for determining operating conditions of a surgical pump system connected to a high resistance inflow cannula relative to a surgical site in a joint of a patient body for receiving the inflow cannula and an endoscope comprising:
providing a pump system having a pump control processor and an inflow drive mechanism including an inflow pump motor for outputting fluid through the inflow cannula to the surgical site disposed in the joint;
providing an inflow pump cassette for mounting to the inflow drive mechanism;
providing a pump housing configured to include the inflow drive mechanism and to receive the inflow pump cassette in driving relation with the inflow drive mechanism;
initially driving the inflow pump motor at a cannula in-joint test RPM value;
measuring P head with a pump pressure sensor associated with the inflow drive mechanism;
determining that measured P head is greater than a P head cannula in-joint value within a predetermined cannula in-joint test time as a result of the inflow cannula being disposed at the surgical site;
reducing the RPM value that is output by the inflow pump motor to a flow test RPM value after the determination that P head is greater than the P head cannula in-joint value; and
determining that measured P head is less than or equal to a P head flow test value within a predetermined flow test time as a result of adequate fluid flow to the surgical site in the joint;
wherein the pump control processor is configured to obtain the cannula in-joint test RPM value, the flow test RPM value, the P head cannula in-joint value and the P head flow test value for determining that the identified inflow cannula and the identified endoscope are disposed at the surgical site in the joint and that adequate fluid flow is provided to the surgical site.

2. The method for determining operating conditions of a surgical pump system connected to a high resistance inflow cannula relative to a surgical site in a joint of a patient body according to claim 1 , wherein the pump control processor is configured to test check that the 1st and 2nd load coefficients for an inflow mode are accurate for the inflow cannula that is in fluid communication with a surgical site in a joint by:
obtaining load coefficients from a look-up table based on the properties of the identified endoscope and the identified inflow cannula, and wherein the load coefficients and a P loss equation define a desired P loss curve;
obtaining a run test RPM value and a P head end test value;
measuring and storing P head as a P head run test start value and storing a start time;
powering the inflow pump motor at the run test RPM value;
measuring P head and determining that P head is greater than the P head end test value within a predetermined run test time to prevent an error indication;
storing an end time whereat measured P head greater than is the P head end test value;
calculating a pressure difference between the P head run test start value and the P head end test value;
calculating a time difference between the start time and the end time;
calculating and normalizing a measured slope from the pressure difference and the time difference;
comparing the measured slope with a stored slope corresponding to the identified cannula and the identified endoscope; and
providing a hardware error indication and idling the pump motor when the measured slope is not greater than the stored slope indicating a possible overpressure condition for the surgical site in the joint,
wherein the control pump processor enables use of the pump system when the measured slope is greater than the stored slope.

3. The method of claim 1 , wherein:
the pump system further includes:
an input interface for manually or automatically receiving inputs of a type of joint for a surgery, a predetermined desired in-joint pressure value and a type of inflow cannula for use in the pump system;
an inflow pump motor measuring device for measuring revolutions per minute (RPM) of the motor to obtain a RPM value for the inflow pump motor; and
a pump memory device configured for storing pressure loss data for identified known cannulas, the pump control processor determining a 1 st load coefficient (COEF 1 ) and a 2 nd load coefficient (COEF 2 ) for a second order polynomial pressure loss equation based on properties of the identified inflow cannula;
wherein the pump control processor executes an algorithm to calculate a pressure loss P loss determined by the 1 st and 2 nd load coefficients and the RPM value of the inflow pump motor by applying the P loss equation:
P loss =COEF 1 ×(RPM value) 2 +COEF 2 ×(RPM value),

wherein the pump control processor determines an in-joint pressure value P joint by applying the equation:
P joint =P head −P loss ,

and
wherein the pump control processor provides at least pump drive signals to drive at least the inflow pump motor in order to maintain the predetermined desired joint pressure value.

4. The method of claim 3 , wherein:
the inflow pump motor outputs fluid to the surgical site via the endoscope and the inflow cannula, the input interface receives an input of the type of endoscope, the pump control processor receives identification information for the endoscope, and the pump memory device stores pressure loss data for the identified known endoscope;
the pump control processor uses a look-up table to find COEF 1 and COEF 2 for the second order polynomial pressure loss equation based on properties of the identified endoscope and the identified inflow cannula;
the pump control processor loads an inflow coefficient from a look-up table based on the properties of the identified endoscope and the identified inflow cannula for calculating the inflow rate for a given inflow pump motor RPM value; and
the load coefficients and the P loss equation define a pressure loss curve.

5. The method of claim 3 , further including providing a surgical device ON/OFF operating condition sensor for sensing the ON/OFF operating condition of a surgical device used at a surgical site in the joint of the patient body that is being surgically treated, wherein the ON/OFF operating condition is provided to the pump control processor for assisting in the calculation of the pump drive signals.

6. The method of claim 5 , further including providing a bus connection that provides communication between the surgical device and the pump control processor.

7. The method of claim 6 , wherein the surgical device comprises an RF probe and wherein the bus connection communicates to the pump control processor at least one of a power level setting for the RF probe, identification data for the RF probe and real-time ON/OFF operating condition of the RF probe, and wherein the pump control processor utilizes information received over the bus connection to assist in the determination of the pump drive signals for at least the inflow pump motor.

8. The method of claim 6 , wherein the surgical device comprises a shaver, and wherein the bus connection communicates to the pump control processor at least one of a real-time RPM operating value for a shaver motor, a shaver identifier, a window size for the shaver, a real-time ON/OFF operating condition of the shaver and a position of a variable suction lever that controls the amount of fluid removed through the shaver, wherein the pump control processor utilizes information communicated over the bus connection to assist in the calculation of the pump drive signals.

9. The method of claim 3 , further including:
providing an outflow drive mechanism including an outflow pump motor obtaining fluid from the surgical site via at least an outflow cannul

Assignees

• Woolford Brady
• Smith Jesse
• Chernyy Nikolai
• Hamel Andrew
• Hilldoerfer Michael
• Benamou Steffan
• Stryker Corp

Inventors

• Woolford Brady
• Smith Jesse
• Chernyy Nikolai
• Hamel Andrew
• Hilldoerfer Michael
• Benamou Steffan

Classifications

• A61M3/0201

  Cassettes therefor · CPC title

• A61M1/72

  Cassettes forming partially or totally the fluid circuit · CPC title

• A61M3/0258

  by means of electric pumps · CPC title

• A61B1/00045

  Display arrangement · CPC title

• A61M1/77

  Suction-irrigation systems (aspiration tips supplying fluids A61M1/85; specific for negative pressure wound therapy A61M1/92; combined with tracheal tubes A61M16/0463) · CPC title