Cordless, powered surgical tool

• US 6,960,894 B2
• Filed: 08/01/2002
• Issued: 11/01/2005
• Est. Priority Date: 08/01/2002
• Status: Active Grant

• Current Assignee: Stryker Corporation
• Original Assignee: Stryker Corporation
• Inventors: Nic, David M., Philipp, Chris, Walen, James G., Carusillo, Steve
• Primary Examiner(s): DUDA, RINA I
• Application Number:
  US10/210,325
• Publication Number:
  US 20040022527A1
• Time in Patent Office: 1,188 Days
• Field of Search: 318/139, 318/255, 318/268, 318/798, 318/799, 318/807, 318/810, 318/811, 318/432, 318/434, 318/138, 318/254, 318/439, 318/461, 388800-804, 388/806, 388/816, 388/937, 606/32, 606/82
• US Class Current: 318/400.01
• CPC Class Codes: A61B 17/142 with reciprocating saw blades, e.g. with cutting edges at the distal end of the saw blades
• CPC Class Codes: A61B 17/1626 Control means; Display units
• CPC Class Codes: A61B 2017/00367 Details of actuation of instruments, e.g. relations between pushing buttons, or the like, and activation of the tool, working tip, or the like
• CPC Class Codes: A61B 2017/00734 battery operated
• CPC Class Codes: Y10S 388/937 Hand tool

Abstract

A powered tool for performing surgical procedures. The tool includes a handpiece in which a power generating unit is housed. A control member is mounted to the handpiece. The control member is mounted to the handpiece so that the orientation of the control member can be selectively set relative to the point to which it is mounted to the handpiece and so it can move relative to a reference point on the handpiece. A control module monitors the orientation of the control member and its position relative to the reference point. Based on the control member orientation and position, the control module generates signals to regulate the operation of the power generating unit. When the power generating unit is a motor, the control module generates signals to ensure that the maximum speed at which the motor can be driven is less than the no load speed.

Claims

1. A powered surgical saw, said saw including:

a handpiece;

a motor disposed in said handpiece for driving a saw-blade in a back-and-forth movement at a variable speed in response to a variable energization signal;

a battery connected to said handpiece to provide energization power to said motor;

a user-actuated control member movably mounted to said handpiece, said control member being rotatable about an axis between a first orientation and a second orientation, and for each orientation, being displaceable along said axis between an initial position and a final position, with a plurality of user-selected intermediate positions between the initial and final positions, each said position being representative of a user selected motor speed; and

a speed limiting assembly configured to limit the speed of said motor so that, when said control member is rotated into said first orientation and displaced to said corresponding final position, said speed limiting assembly causes said motor to run at a first maximum speed, and when said control member is rotated into said second orientation and displaced to said corresponding final position, said speed limiting assembly causes said motor to run at a second maximum speed that is less than said first maximum speed.

2. The powered surgical saw according to claim 1, wherein said first maximum speed is equal to or less than a no-load speed.

3. The powered surgical saw according to claim 1, wherein said speed limiting assembly includes a mechanical member connected to said handpiece and which is positioned adjacent said control member such that when said control member is rotated into said first orientation, said mechanical member does not limit displacement of said control member, and when said control member is rotated into said second orientation, said mechanical member limits displacement of said control member by a predetermined amount.

4. The powered surgical saw according to claim 1, wherein said control member is rotatable about said axis into a third orientation wherein said control member in said third orientation is prevented from being displaced along said axis.

5. The powered surgical saw according to claim 4, wherein said third orientation is located between said first orientation and second orientation.

6. The powered surgical saw according to claim 1, further comprising:

at least one moveable sensed element internal to said handpiece and displaceable between a first position and a second position, wherein displacement of said control member causes displacement of said sensed element between said first position and said second position; and

a speed regulator configured to regulate the energization of said motor, said speed regulator including at least one sensor configured to wirelessly monitor the displacement of said sensed element;

wherein said speed regulator energizes said motor to run at a first predefined speed when said sensed element is in said first position, and energizes said motor to run at one of said first maximum speed and second maximum speed when said sensed element is in said second position, and energizes said motor to run at an intermediate speed between said first predefined speed and said one of said first maximum speed and said second maximum speed when said sensed element is in an intermediate position between said first position and said second position.

7. The powered surgical saw according to claim 6, wherein said speed regulator is configured to hold the motor speed at a constant speed as a function of displacement of said control member when a load applied to said motor varies.

8. The powered surgical saw according to claim 6, wherein said sensed element comprises a magnet, and said sensor comprises a magnetic field sensor.

9. The powered surgical saw according to claim 1, further comprising:

a linkage assembly mounted to said handpiece and connected to a shaft of said motor for converting a rotary movement of said motor shaft to a back-and-forth movement; and

a coupling assembly mounted to said handpiece and connected to said linkage assembly to engage in back-and-forth movement in response to actuation of said linkage assembly by said motor shaft, said coupling assembly being configured to removably receive said saw blade so that said saw blade engages in back-and-forth movement with said coupling assembly.

10. The powered surgical saw, said saw including:

a handpiece;

a motor disposed in said handpiece for driving a saw-blade in a back-and-forth movement at a variable speed in response to a variable energization signal;

a battery connected to said handpiece to provide energization power to said motor;

a user-actuated control member moveably mounted to said handpiece, said control member being rotatable about an axis between a first orientation and a second orientation, and for each orientation, being displaceable along said axis between an initial position and final position, with a plurality of user-selected intermediate positions between the initial and final positions, each said position being representative of a user selected motor speed;

a motor regulator connected to said motor and to said battery for selectively applying an actuation signal to said motor, said motor regulator being configured to drive said motor in a first rotational direction when said control member is rotated into the first orientation and subsequently displaced toward said corresponding final position, and to drive said motor in a second rotational direction when said control member is rotated into its second orientation and subsequently displaced toward said corresponding final position; and

a speed limiting assembly configured to limit the speed of said motor so that, when said control member is rotated into said first orientation and displaced to said corresponding final position, said speed limiting assembly prevents said motor from running at a speed greater than a first maximum speed, and when said control member is rotated into said second orientation and displaced to said corresponding final position, said speed limiting assembly prevents said motor from running at a speed greater than a second maximum speed that is less than said first maximum speed.

11. The powered surgical saw according to claim 10, wherein said speed limiting assembly includes a mechanical member that connects to said handpiece and which is positioned adjacent said control member such that when said control member is rotated into said first orientation, said mechanical member does not limit displacement of said control member toward said corresponding final position, and when said control member is rotated into said second orientation, said mechanical member limits displacement of said control member toward said corresponding final position by a predetermined amount.

12. The powered surgical saw according to claim 10, further comprising:

three moveable sensed elements that are internal to said handpiece, each of said sensed elements being selectively displaceable between a corresponding first position and a corresponding second position in response to displacement of said control member;

a speed regulator configured to regulate the energization of said motor, said speed regulator including three sensors, each said sensor corresponding to one of said three movable sensed elements and configured to wirelessly monitor displaement of its corresponding sensed element;

wherein a first and second of said three sensed elements are displaced toward their corresponding second positions when said control member is rotated into said first orientation and subsequently displaced towards its corresponding final position, and wherein said second and a third of said three sensed elements are displaced toward their corresponding second positions when said control member is rotated into said second orientation and subsequently displaced towards its corresponding final position; and

wherein detected displacement of said first sensed element by its corresponding first sensor results in said motor regulator being configured to drive said motor in the first direction at a speed equal to or less than said first maximum speed, and detected displacement of said third sensed element by its corresponding third sensor results in said motor regulator being configured to drive said motor in the second direction at a speed equal to or less than said second maximum speed, and detected displacement of said second sensed element by its corresponding second sensor results in energization of said motor to drive same at a speed up to said first or second maximum speed in the corresponding said first or second direction designated by said motor regulator.

13. The powered surgical saw according to claim 12, wherein said sensed element comprises a magnet, and said sensor comprises a magnetic field sensor.

14. A powered surgical tool, said tool comprising:

a handpiece;

a variable speed motor disposed in said handpiece and configured to operate at a select speed in response to the application of a select actuation signal to said motor;

a battery connected to said handpiece to provide energization power to said motor;

a user-actuated control member moveable mounted to said handpiece and selectively rotatable into one of at least two orientations relative to said handpiece, and selectively displaceable between first and second spatial positions relative to said handpiece when said control member resides in one of said at least two orientations;

a sensor assembly disposed in said handpiece, said sensor assembly including;

at least one orientation sensor configured to wirelessly detect when said control member resides in one of said at least two orientations; and

a displacement sensor configured to wirelessly detect an amount of spatial displacement undergone by said control member relative to said handpiece after said control member has been rotated into one of said at least two orientations and displaced from said first spatial position towards said second spatial position;

a motor speed limiting circuit configured to selectively restrict a maximum operating speed of said motor to one or more predetermined speeds in response to said orientation sensor detecting said control member in one of said at least two orientations.

15. The powered surgical tool according to claim 14, wherein said motor speed limiting circuit restricts the maximum operating speed of said motor to a first predetermined operating speed when said at least one orientation sensor detects said control member residing in a first of said at least two orientations;

said motor speed limiting circuit restricts the maximum operating speed of said motor to a second predetermined operating speed when said at least one orientation sensor detects said control member residing in a second of said at least two orientations; and

wherein said first predetermined operating speed is equal to or less than a no-load speed of said motor, and said second predetermined operating speed is less than said first predetermined operating speed.

16. The powered surgical tool according to claim 14, wherein said sensor assembly comprises at least two orientation sensors and a displacement sensor, with a first of said at least two orientation sensors configured to wirelessly detect when said control member is in a first of said at least two orientations, and a second of said at least two orientation sensors configured to wirelessly detect when said control member is in a second of said at least two orientations;

wherein said motor speed limiting circuit restricts the maximum operating speed of said motor to a first predetermined speed when said first of said at least two orientation sensors detects said control member in said first orientation, and restricts the maximum operating speed of said motor to a second predetermined speed different from said first predetermined speed, when said second of said at least two orientation sensors detects said control member in said second orientation.

17. The powered surgical tool according to claim 16, further comprising:

three displaceable carriages disposed in said handpiece, with each carriage mounting thereon a sensed element that can be detected, respectively, by one of said at least two orientation sensors and said displacement sensor;

a first linkage member attached to said control member and which displaces a first of said carriages towards a first of said at least two orientation sensors when said control member is rotated into a first of said at least two orientations and displaced between said first and second spatial positions relative to said handpiece;

a second linkage member that attaches to said control member and which displaces a second of said carriages towards a second of said at least two orientation sensors when said control member is rotated into a second of said at least two orientations and displaced between said first and second spatial positions relative to said handpiece; and

a third linkage member that selectively attaches a third carriage to said first and second carriages such that said third carriage is displaced towards said displacement sensor when either said first carriage or said second carriage is displaced, respectively, towards said first and second orientation sensor.

18. The powered surgical tool according to claim 14, wherein said control member is rotatably attached to said handpiece and is movably attached to said handpiece so that a portion of said control member is selectively displaceable between said first and second spatial positions relative to said handpiece;

and

said displacement sensor is configured to wirelessly detect an amount of spatial displacement undergone by said portion of said control member relative to said handpiece after said control member has been rotated into one of said at least two orientations.

19. The powered surgical tool according to claim 14, wherein selective displacement of said control member between said first and second spatial positions is accomplished by retracting said control member towards, or extending said control member away from, said handpiece.

20. The powered surgical tool according to claim 14, wherein said motor speed limiting circuit comprises a voltage divider circuit.

21. The powered surgical tool according to claim 20, wherein said voltage divider circuit includes;

one of a switch and jumper that can be placed into one of at least two states; and

one or more resistors configured to provide one of at least two electrical current resistance values depending on said state of said one switch and jumper.

22. The powered surgical tool according to claim 14, wherein said at least one orientation sensor and displacement sensor output a digital signal, and detection of said control member orientation is indicated by a change in state in the digital signal output by said at least one orientation sensor.

23. The powered surgical tool according to claim 22, wherein said motor speed limiting circuit includes non-volatile memory (NOVRAM) that contains data defining said first maximum speed and said second maximum speed of said motor.

24. The powered surgical tool according to claim 23, wherein said non-volatile memory is configured to be removable and replaceable, such that said first maximum speed and second maximum speed can be selected depending on the non-volatile memory inserted into said motor speed limiting circuit.

25. The powered surgical tool according to claim 14, further comprising a speed regulator configured to regulate a speed of said motor based upon a user selected speed, an actual motor speed, and a motor load.

26. The powered surgical tool according to claim 14, wherein said at least one orientation sensor and said displacement sensor comprise one of a magnetic field sensor and an optical sensor.

27. The powered surgical tool according to claim 26, wherein said user-actuated control member includes at least one magnet configured to be displaced relative to said at least one orientation sensor and displacement sensor when said control member is selectively rotated into one of said at least two orientations and selectively displaced between said first and second spatial positions.

28. The powered surgical tool according to claim 26, wherein said user-actuated control member includes a shutter that directs light upon said at least one orientation sensor and displacement sensor, with a size of said shutter adjusting in response to displacement of said control member between said first and second spatial positions.

29. A powered surgical saw, said saw including:

a handpiece;

a motor disposed in said handpiece for driving a saw-blade in a back-and-forth movement at a variable speed in response to a variable energization signal;

a battery connected to said handpiece to provide energization power to said motor;

a user-actuaged control member movably mounted to said handpiece, said control member being displaceable between an initial position and a final position, with a plurality of user-selected intermediate positions between the initial and final positions, each said position being representative of a user selected motor speed; and

a speed limiting assembly located on said handpiece and selectively moveable into one of at least first and second states, said speed limiting assembly when in said first state being disposed to restrict displacement of said control member by a first predetermined amount so as to limit an operating speed of said motor to a first predetermined maximum operating speed, and when in said second state being disposed to restrict displacement of said control member by a second predetermined amount so as to limit the operating speed of said motor to a second predetermined operating speed that is less than said first predetermined operating speed.

30. The powered surgical saw according to claim 29, wherein said speed limiting assembly comprises a sleeve that mounts around a shaft of said control member and which can be rotated into one of said first and second states.

31. The powered surgical saw according to claim 29, wherein

said user-actuated control member is displaceable along a first axis;

said speed limiting assembly is moveably mounted on said handpiece and configured to be selectively placed into one of said first and second states by displacement along a second axis different than said first axis; and

said control member is movably mounted upon said speed limiting assembly such that said control member and speed limiting assembly are collectively displaced along said second axis to one of said first and second states.

32. A powered surgical saw, said saw including:

a handpiece;

a motor disposed in said handpiece for driving a saw-blade in a back-and-forth movement at a variable speed in response to a variable energization signal;

a battery connected to said handpiece to provide energization power to said motor;

a user-actuated control member movably mounted to said handpiece, said control member being displaceable between an initial position and a final position, with a plurality of user-selected intermediate positions between the initial and final positions, each said position being representative of a user selected motor speed;

at least one moveable sensed element internal to said handpiece and displaceable between a first position and a second position, wherein displacement of said control member causes displacement of said sensed element between said first position and said second position;

a speed regulator configured to regulate the energization of said motor, said speed regulator including at least one sensor configured to monitor the displacement of said sensed element, said speed regulator energizing said motor to run at a first predefined speed when said sensed element is in said first position, and energizing said motor to run at a second predefined speed when said sensed element is in said second position, and energizing said motor to run at an intermediate speed between said first predefined speed and said second predefined speed when said sensed element is in an intermediate position between said first position and said second position; and

a speed limiting assembly located on said handpiece and selectively configured into one of at least first and second states, said speed limiting assembly when in said first state is disposed to restrict displacement of said at least one sensed element by a first predetermeined amount, and when in said second state is disposed to restrict displacement of said at least one sensed element by a second predetermined amount different than said first predetermined amount;

wherein an operating speed of said motor is equal to or less than a first maximum speed when displacement of said at least one sensed element is restricted by said first predetermined amount, and is equal to or less than a second maximum speed when displacement of said at least one sensed element is restricted by said second predetermined amount, with said second maximum speed being less than said first maximum speed.

33. The powered surgical saw according to claim 32, wherein said speed limiting assembly comprises a mechanical sleeve that mounts around a shaft of said control member and which can be rotated into one of said first and second states.

34. The powered surgical saw according to claim 32, wherein

said user-actuated control member is displaceable along a first axis;

said speed limiting assembly is moveably mounted on said handpiece and configured to be selectively placed into one of said first and second states by displacement along a second axis different than said first axis; and

said control member is movably mounted upon said speed limiting assembly such that said control member and speed limiting assembly are collectively displaced along said second axis to one of said first and second states.

35. The powered surgical saw according to claim 32, further comprising:

at least one displaceable carriage disposed in said handpiece and upon which is mounted said at least one sensed element; and

at least one linkage member attached to said control member and which displaces said at least one carriage towards said at least one sensor when said control member is displaced between said initial position and final position.