Sensing arrangement for control of powered cutting device

• US 20100100112A1
• Filed: 10/21/2009
• Published: 04/22/2010
• Est. Priority Date: 10/22/2008
• Status: Active Grant

• Current Assignee: Stryker Corporation
• Original Assignee: Stryker Corporation
• Inventors: Dierck, Ryon, Kauker, Barry, Cover, Reid
• Granted Patent: US 8,226,677 B2
• Time in Patent Office: Days
• US Class Current: 606/180
• CPC Class Codes: A61B 17/32002 with continuously rotating, oscillating or reciprocating cutting instruments
• CPC Class Codes: A61B 2017/00017 Electrical control of surgical instruments
• CPC Class Codes: A61B 2017/00022 Sensing or detecting at the treatment site
• CPC Class Codes: A61B 2217/005 with suction drainage system
• CPC Class Codes: A61M 1/842 rotating continuously rotating surgical cutting instruments A61B17/32002

Abstract

Sensing arrangements for a handpiece sense suction pressure or fluid flow within a suction path to determine the position of a movable cutting element relative to a fixed cutting element of a cutting accessory. A controller calculates actual speed of the movable cutting element from measured pressure or measured fluid flow. The cutting elements have openings that, when aligned, form a window. The controller controls power to a motor that drives the cutting element. When the handpiece is deactivated, the controller stops the movable cutting element at a predetermined position to close or partially close the window. The controller controls the cutting speed in view of joint pressure combined with suction pressure, or in view of fluid flow through the suction path, to maintain an optimal fluid flow rate that enhances the cutting action of the cutting accessory. Pressure or flow sensors may detect a clog in the suction path.

Claims

1. A method for operating a handpiece including a coupling assembly at a distal end thereof for coupling to a proximal end of a cutting accessory and including a motor for driving the cutting accessory, the cutting accessory comprising a fixed element with an opening at a distal end thereof and a driven element with an opening at a distal end thereof, the openings together defining a window for at least partially opening and closing during movement of the driven element, the method comprising the steps of:

providing suction through a suction tube to a suction bore in the handpiece, the suction tube and the suction bore comprising a suction path;

actuating the driven element of the cutting accessory by operating the motor;

determining the position of the driven element relative to the fixed element by sensing at least one of pressure and fluid flow in the suction path; and

controlling the motor to stop the driven element at a predetermined position in response to the sensed pressure or fluid flow.

2. The method of claim 1, wherein the step of actuating the driven element comprises rotating the driven element within and relative to the fixed element.

3. The method of claim 1, wherein the step of actuating the driven element comprises reciprocating the driven element within the fixed element.

4. The method of claim 1, wherein the sensing step comprises sensing maximum pressure values and minimum pressure values that correspond to a position of the driven element relative to the fixed element, the maximum and minimum values repeating at a frequency corresponding to the velocity of the driven element.

5. The method of claim 4, including the steps of:

comparing the maximum and minimum pressure values over the entirety of at least two time periods to determine when the maximum pressure remains below a predetermined value to detect a clog in the suction path; and

informing a user of the presence of a clog.

6. The method of claim 1, wherein the step of stopping the driven element at a predetermined position comprises stopping the driven element at a position relative to the fixed element so that the window defined by the fixed element and the driven element is closed and no fluid is capable of passing from a surgical site through the cutting accessory and into the suction bore of the handpiece.

7. A handpiece including a motor for driving a cutting accessory having a fixed element and a driven element for forming a window that at least partially opens and closes during driving of the driven element, the handpiece comprising:

a housing including a suction bore therein;

a coupling assembly disposed at a distal end of the housing for receiving a cutting accessory;

a motor disposed in the housing for driving a cutting accessory;

a sensor disposed in the housing for sensing fluid flow or pressure in the suction bore and providing a sensor output; and

a controller for determining movement and position of a driven element of a cutting accessory from the sensor output and for controlling the motor for stopping the driven element in a predetermined position.

8. The handpiece of claim 7, wherein the sensor senses pressure in the suction bore.

9. The handpiece of claim 7, comprising an actuator for providing an actuator output to said controller and wherein the sensor comprises a pressure sensor for providing the sensor output.

10. The handpiece of claim 7, comprising an actuator for providing an actuator output to said controller, and wherein the sensor comprises a flow sensor for measuring fluid flow through the suction bore, whereby said controller receives the actuator output and the sensor output to control the motor and operate said cutting accessory at an optimal speed for maximizing cutting by the handpiece.

11. A surgical system comprising:

an elongate handpiece comprising a housing with a motor disposed therein, the handpiece including a suction bore;

a suction tube connected to said suction bore at the proximal end of said handpiece;

a cutting accessory having a proximal end coupled at a distal end of said handpiece, said cutting accessory comprising a fixed element and a driven element driven by the motor, wherein during operation of said driven element a window opening defined by openings in the fixed element and the driven element periodically at least partially opens and closes for providing a fluid path from an exterior of said cutting accessory, and through a suction channel of said cutting accessory to said suction bore, wherein said suction tube, said suction bore and the suction channel comprise a suction path;

at least one of a pressure sensor and a flow sensor for providing a signal output;

an actuator for providing an actuator output to power the cutting accessory; and

a controller for receiving the signal output and the actuator output, and for operating the motor to power the cutting accessory at a desired speed corresponding to a predetermined optimal fluid flow rate through the suction bore in response to the signal output and the actuator output.

12. The surgical system of claim 11, wherein, during stopping of said motor, said motor driving said driven element to a predetermined position relative to said fixed element to provide a predetermined dimension for the opening or no fluid path through the window opening from the exterior of said cutting accessory to said suction channel.

13. The surgical system of claim 11, wherein the window between the driven element and the fixed element is closed so that essentially no fluid path opening is provided from the exterior of the cutting accessory to the suction channel.

14. The surgical system of claim 11, wherein said sensor comprises the pressure sensor disposed in said handpiece for detecting pressure in the suction bore.

15. The surgical system of claim 14, wherein said controller is disposed within said handpiece.

16. The surgical system of claim 15, wherein said actuator is disposed on said handpiece.

17. The surgical system of claim 11, wherein said sensor comprises a flow sensor disposed in fluid communication with said suction tube.

18. The surgical system of claim 17, wherein said actuator comprises a foot switch.

19. The surgical system of claim 11, wherein said sensor comprises the flow sensor for sensing fluid flow through said suction path.

20. The surgical system of claim 19, wherein said flow sensor comprises one of an ultrasonic flow sensor and an optical flow sensor disposed in said housing.