BACKGROUND

1. Technical Field

The present disclosure relates to surgical devices and, more specifically, to speed control systems for powered surgical devices.

2. Discussion of Related Art

A number of surgical device manufacturers have developed product lines with proprietary drive systems for operating or manipulating the surgical device. In many instances the surgical devices include a handle assembly, which is reusable, and a disposable end effector or the like that is selectively connected to the handle assembly prior to use and then disconnected from the handle assembly following use in order to be disposed of or in some instances sterilized for re-use.

Many of the existing end effectors for use with many of the existing surgical devices or handle assemblies linearly advance a firing assembly to actuate the end effector. For example, end effectors for performing endo-gastrointestinal anastomosis procedures, end-to-end anastomosis procedures, and transverse anastomosis procedures, each typically require a linear advancement of a firing assembly in order to be operated.

Existing handle assemblies advance the firing assemblies at a predetermined speed. In addition, some handle assemblies include feedback systems that reduce the predetermined speed in response to surgical conditions such as tissue thickness. However, a clinician using the surgical device lacks control of the firing speed of the handle assembly.

Accordingly, there is a need to provide a clinician with an ability to vary the speed of advancement a firing assembly based surgical conditions observed by the clinician.

SUMMARY

In an aspect of the present disclosure, a surgical device includes a housing, a drive shaft, a motor, a control button, and a motor speed controller. The motor is configured to rotate the drive shaft that is disposed within housing. The control button is disposed on the housing and the motor speed controller is operably associated with the control button. The motor speed controller varies an angular velocity of the motor as a function of a percent of actuation of the control button between an unactuated position and a fully actuated position.

In aspects, the motor speed controller includes a magnet and a Hall Effect sensor. The magnet may be attached to the control button and the Hall Effect sensor may be fixedly mounted within the housing.

In some aspects, the motor speed controller includes a light source, a set of louvers, and a photo sensor. The set of louvers may be disposed between the light source and the photo sensor. The set of louvers can have a closed configuration in which the set of louvers prevent light emitted from the light source from reaching the photo sensor and an open configuration in which at least a portion of light emitted from the light source illuminates the photo sensor. The motor speed controller may include a drive gear operably associated with the set of louvers to transition the set of louvers between the open and closed configurations. The control button may include a rod having a toothed rack that meshingly engages the drive gear to transition the set of louvers between the open and closed configurations in response to actuation of the control button.

The function can be a linear function or a stepped function. When the function is a stepped function, the stepped function can be a two or a three step function. The stepped function can have a dead spot between about zero percent and about five percent actuation of the control button where the motor does not rotate the drive shaft.

In certain aspects, the surgical device includes a biasing member disposed about the control button to urge the control button towards the unactuated position. The biasing member can have a spring constant such that an actuation force required to actuate the control button linearly increases to affect actuation of the control button towards the fully actuated position. Alternatively, the biasing member can have a first spring constant and a second spring constant such that an actuation force required to actuate the control button increases in a stepped manner to affect actuation of the control button towards the fully actuated position.

In another aspect of the present disclosure, a method of controlling an angular velocity of a drive shaft of a motor of a surgical device includes actuating a control button of the surgical device a first distance towards a fully actuated position such that a motor speed controller transmits a control signal to the motor to rotate the drive shaft at a first angular velocity and continuing to actuate the control button of the surgical device a second distance towards the fully actuated position such that the motor speed controller transmits a second control signal to the motor to rotate the drive shaft a second angular velocity greater than the first angular velocity.

In aspects, continuing to actuate the control button of the surgical device a section distance transitions a set of louvers towards an open configuration such that an amount of light emitted from a light source reaching a photo sensor increases. Alternatively, continuing to actuate the control button of the surgical device a second distance can move a magnet closer to a Hall Effect sensor.

Further, to the extent consistent, any of the aspects described herein may be used in conjunction with any or all of the other aspects described herein.

