Patent Description:
Electromechanical surgical instruments include a reusable handle assembly and disposable loading units and/or single use loading units, such as, for example, surgical end effectors. The end effectors are 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. There are one or more drive mechanisms within the handle assembly for carrying out the various functions of the end effector. <CIT> describes an electromechanical surgical system that has a drive motor supported in a handle assembly and extending to a drive gear, a selector cam defining a recess, and an output gear rotatable relative to an output shaft while the selector cam is in position.

In one aspect of the disclosure, a transmission assembly for use in a hand-held surgical instrument is provided and includes a housing, a main drive motor supporting a main drive gear, first and second output gears operably coupled to the main drive gear and configured to rotate in response to a rotation of the main drive gear, first and second output shafts rotatably supported in the housing, and a selector cam associated with the first and second output shafts. The selector cam is configured to move between a first position and a second position. In the first position, the selector cam non-rotatably couples the first output shaft to the first output gear and the second output gear is rotatable relative to the second output shaft. In the second position, the selector cam non-rotatably couples the second output shaft to the second output gear and the first output gear is rotatable relative to the first output shaft.

In aspects, the transmission assembly may further include a first coupling shaft non-rotatably coupled to the first output shaft and a second coupling shaft non-rotatably coupled to the second output shaft. The first coupling shaft may be configured to non-rotatably engage the first output gear when the selector cam is in the first position such that only the first output shaft of the first and second output shafts rotates in response to the rotation of the main drive gear. The second coupling shaft may be configured to non-rotatably engage the second output gear when the selector cam is in the second position such that only the second output shaft of the first and second output shafts rotates in response to the rotation of the main drive gear.

In aspects, the first coupling shaft may extend through the first output gear and may be slidable in the first output gear between a proximal position and a distal position. In the proximal position, the first coupling shaft may be non-rotatably engaged with the first output gear. In the distal position, the first coupling shaft may be disengaged from the first output gear.

In aspects, the first coupling shaft may have a proximal end portion engaged with the selector cam, and a distal end portion having a gear. The first output gear may have a geared inner surface configured to meshingly engage with the gear of the distal end portion of the first coupling shaft when the first coupling shaft is in the proximal position.

In aspects, the selector cam may have a distal-facing surface engaged to the first and second coupling shafts. The distal-facing surface of the selector cam may have a recess in which a proximal end portion of the first coupling shaft is received when the selector cam is in the first position.

In aspects, the selector cam may have an arcuate shape and may be configured to rotate around the main drive motor between the first and second positions.

In aspects, the distal-facing surface of the selector cam may have a first ramped end portion, and an opposite second ramped end portion.

In aspects, the first and second coupling shafts may each be resiliently biased toward the proximal position. The selector cam may be configured to selectively maintain only one of the first or second coupling shafts in the distal position.

In aspects, the transmission assembly may further include a third output shaft and a third output gear operably coupled to the main drive gear. The selector cam may be configured to move to a third position, in which the first and second output shafts are disengaged from the respective first and second output gears and the third output shaft is non-rotatably engaged to the third output gear.

In aspects, the transmission assembly may further include a selector motor supporting a gear that is operably coupled to the selector cam. The selector motor may be configured to move the selector cam between the first and second positions.

In aspects, the selector cam may have a plurality of teeth in meshing engagement with the gear of the selector motor.

In accordance with another aspect of the disclosure, a handle assembly for operating a surgical end effector is provided and includes a handle housing and a transmission assembly. The handle housing has a barrel portion and a handle portion extending from the barrel portion. The transmission assembly is supported in the barrel portion of the handle housing and includes a main drive motor having a main drive gear, first, second, and third output shafts, first, second, and third output gears operably coupled to the main drive gear and configured to rotate in response to a rotation of the main drive gear, a selector cam, and a selector motor operably coupled to the selector cam. The selector motor is configured to move the selector cam relative to the first, second, and third output shafts between a first position and a second position. In the first position, the first output shaft is non-rotatably coupled to the first output gear. In the second position, the second output shaft is non-rotatably coupled to the second output gear. In the third position, the third output shaft is non-rotatably coupled to the third output gear.

In aspects, the transmission assembly may further include a first coupling shaft non-rotatably coupled to the first output shaft, a second coupling shaft non-rotatably coupled to the second output shaft, and a third coupling shaft non-rotatably coupled to the third output shaft.

In aspects, the first coupling shaft may be configured to translate into non-rotatable engagement with the first output gear when the selector cam is moved to the first position such that only the first output shaft rotates in response to a rotation of the main drive gear when the selector cam is in the first position.

In aspects, the second coupling shaft may be configured to translate into non-rotatable engagement with the second output gear when the selector cam is moved to the second position such that only the second output shaft rotates in response to the rotation of the main drive gear when the selector cam is in the second position.

In aspects, the third coupling shaft may be configured to translate into non-rotatable engagement with the third output gear when the selector cam is moved to the third position such that only the third output shaft rotates in response to the rotation of the main drive gear when the selector cam is in the third position.

In aspects, the first, second, and third coupling shafts may each be resiliently biased toward a proximal position in which the first, second, and third coupling shafts are respectively non-rotatably engaged with the first, second, and third output gears.

In aspects, the selector cam may be configured to selectively maintain only one of the first, second, or third coupling shafts in a distal position and out of non-rotatable engagement with the respective first, second, and third output gears.

In aspects, the selector cam may have a distal-facing surface configured to engage and maintain a selected one of the first, second, or third coupling shafts in the distal position.

In aspects, the transmission assembly may further include a first coupling shaft non-rotatably coupled to the first output shaft. The first coupling shaft may be configured to translate into non-rotatable engagement with the first output gear when the selector cam is moved to the first position such that only the first output shaft rotates in response to a rotation of the main drive gear when the selector cam is in the first position.

In aspects, the first coupling shaft may extend through the first output gear and may be slidable therein between a proximal position and a distal position. In the proximal position, the first coupling shaft is non-rotatably engaged with the first output gear. In the distal position, the first coupling shaft is disengaged from the first output gear.

In aspects, the selector motor may rotatably support and drive a gear. The selector cam may have a plurality of teeth in meshing engagement with the gear of the selector motor. The teeth of the selector cam may be configured to move the selector cam between the first, second, and third positions.

In aspects, the selector cam may have an arcuate shape and may be configured to rotate around the main drive motor between the first, second, and third positions.

Embodiments of the disclosure are described herein with reference to the accompanying drawings, wherein:.

Embodiments of the presently disclosed surgical instruments are described in detail with reference to the drawings, in which like reference numerals designate identical or corresponding elements in each of the several views. As used herein the term "distal" refers to that portion of the surgical instrument, or component thereof, farther from the user, while the term "proximal" refers to that portion of the surgical instrument, or component thereof, closer to the user.

This disclosure is directed to a transmission assembly disposable within a handle housing of a hand-held surgical instrument. The transmission assembly has a single motor that drives a plurality of output shafts, which are configured to transmit rotational motion to corresponding driven elements of a surgical end effector. The transmission assembly includes a selector cam that selectively operably couples a single output shaft with the motor. When a user depresses a switch, a computer processor within the handle housing determines the desired user request and positions the selector cam in the appropriate position to operate the desired output shaft.

The main advantage of a single motor design is the elimination of motors due to the simple shaft selectable transmission. This transmission design provides the same device performance as a multiple motor design with the advantages of allowing the product to be manufactured at a lower cost. Further, the ergonomics are improved because the physical size and weight of the device will be less and will require fewer electrical components and circuitry which contributes to improved reliability.

With reference to <FIG>, a surgical instrument, in accordance with an embodiment of the disclosure, is generally designated as <NUM>, and is in the form of a powered hand-held electromechanical surgical instrument configured for selective coupling thereto of a plurality of different surgical end effectors (not explicitly shown), for example, a linear surgical stapler end effector, a circular stapler end effector, a hernia tack end effector, or the like. An exemplary end effector configured for actuation and manipulation by the powered hand-held electromechanical surgical instrument <NUM> may be found at least in <CIT>, the entire contents of which being referenced herein.

The hand-held electromechanical surgical instrument <NUM> includes a handle assembly <NUM> and an adapter assembly <NUM> extending distally from the handle assembly <NUM>. The adapter assembly <NUM> has a knob housing <NUM> coupled to the handle assembly <NUM> and a shaft portion <NUM> configured for selective connection with a selected surgical end effector. The knob housing <NUM> may be rotationally coupled to the handle assembly <NUM> and configured to be manually rotated about a longitudinal axis "X" defined by the shaft portion <NUM> to rotate the end effector.

The handle assembly <NUM> includes a handle housing <NUM> consisting of a barrel portion <NUM> substantially aligned with the longitudinal axis "X," and a handle portion <NUM> extending perpendicularly downward from the barrel portion <NUM>. The handle assembly <NUM> includes a printed circuit board or processor <NUM> and a battery <NUM> disposed in the handle housing <NUM>. The printed circuit board <NUM> is configured to be in electrical communication with the battery <NUM> and a main drive motor <NUM> of a transmission assembly <NUM>. The main drive motor <NUM> may be wirelessly connected, connected via a wire, or otherwise electrically connected to the printed circuit board <NUM> and the battery <NUM>. The handle assembly <NUM> also has a fire switch <NUM> configured to actuate the various functions of the end effector and a safety switch <NUM> for preventing an inadvertent actuation of the fire switch <NUM>. The fire switch <NUM> may be a finger switch pivotably coupled to the handle portion <NUM> in communication with the printed circuit board <NUM> for activating the battery <NUM> to ultimately actuate an open/close and staple firing function of the end effector.

With reference to <FIG>, the transmission assembly <NUM> of the handle assembly <NUM> is configured for removable receipt in the barrel portion <NUM> of the handle housing <NUM> and generally includes a body portion or housing <NUM>, the main drive motor <NUM>, a plurality of output shafts <NUM>, <NUM>, <NUM>, a selector cam <NUM>, and a selector motor <NUM>. The main drive motor <NUM> of the transmission assembly <NUM> may be an electric motor and rotatably supports a drive shaft <NUM> about which a main drive gear <NUM>, such as, for example, a spur gear, is non-rotatably fixed. As such, an actuation of the main drive motor <NUM> results in a rotation of the main drive gear <NUM>. In aspects, the main drive motor <NUM> may be considered separate from the transmission assembly <NUM>.

The output shafts <NUM>, <NUM>, <NUM> are configured to be selectively driven by the main drive motor <NUM> whereby the selected output shaft <NUM>, <NUM>, or <NUM> rotates to transmit its rotational motion to a driven element (e.g., drive shaft <NUM> of adapter assembly <NUM> of <FIG>) to ultimately effect a corresponding function of the attached surgical end effector. The output shafts <NUM>, <NUM>, <NUM> are rotatably supported in the transmission housing <NUM> and are resisted from sliding within the transmission housing <NUM> by seals <NUM>. Each of the output shafts <NUM>, <NUM>, <NUM> has a distal end <NUM> configured to non-rotatably couple to the respective driven element of the adapter assembly <NUM>.

With reference to <FIG>, the transmission assembly <NUM> further includes a plurality of output gears, such as, first, second, and third output spur gears <NUM>, <NUM>, <NUM> rotationally supported in the transmission housing <NUM> and about the respective output shafts <NUM>, <NUM>, <NUM>. The output gears <NUM>, <NUM>, <NUM> are rotatably supported about the respective output shafts <NUM>, <NUM>, <NUM> such that the output gears <NUM>, <NUM>, <NUM> are permitted to rotate relative to and about the output shafts <NUM>, <NUM>, <NUM>. The first or intermediate output gear <NUM> is in direct meshing engagement with the main drive gear <NUM>, whereas the second and third output gears <NUM>, <NUM> are operably coupled to the main drive gear <NUM> via the first output gear <NUM>. In this way, an actuation of the main drive motor <NUM> results in the simultaneous rotation of each of the first, second, and third output gears <NUM>, <NUM>, <NUM>.

The transmission assembly <NUM> further includes a plurality of coupling shafts, such as, for example, first, second, and third coupling shafts <NUM>, <NUM>, <NUM> configured to operable couple the respective first, second, and third output gears <NUM>, <NUM>, <NUM> to the first, second, and third output shafts <NUM>, <NUM>, <NUM>, as will be described. The coupling shafts <NUM>, <NUM>, <NUM> are each disposed in a respective hollow interior of the output shafts <NUM>, <NUM>, <NUM> and are slidable therein along a longitudinal axis of the output shafts <NUM>, <NUM>, <NUM> (e.g., as illustrated by double headed arrow of <FIG>) between a proximal position and a distal position. The transmission assembly <NUM> may include a plurality of biasing members, such as, for example, first second, and third coil springs <NUM>, <NUM>, <NUM> configured to resiliently bias the coupling shafts <NUM>, <NUM>, <NUM> relative to the output shafts <NUM>, <NUM>, <NUM> toward the proximal position. Each of the coupling shafts <NUM>, <NUM>, <NUM> has a tab or protrusion <NUM> (<FIG>) that extends through a slit <NUM> defined in each of the output shafts <NUM>, <NUM>, <NUM> such that the first, second, and third output shafts <NUM>, <NUM>, <NUM> rotate with and by a rotation of the respective first, second, and third coupling shafts <NUM>, <NUM>, <NUM>.

Each of the coupling shafts <NUM>, <NUM>, <NUM> has a proximal end portion 150a (<FIG>) that protrudes proximally from the respective output shafts <NUM>, <NUM>, <NUM> and the transmission housing <NUM>, and a distal end portion 150b received in the respective output shaft <NUM>, <NUM>, <NUM>. The distal end portion 150b of each of the coupling shafts <NUM>, <NUM>, <NUM> has a gear <NUM> formed therewith or fixed thereabout, and each of the output gears <NUM>, <NUM>, <NUM> has an inner geared surface <NUM> configured to meshingly engage with the respective gear <NUM> of the coupling shaft <NUM>, <NUM>, <NUM> when a selected one of the coupling shafts <NUM>, <NUM>, <NUM> is in the proximal position. As such, when the selected coupling shaft <NUM>, <NUM>, or <NUM> is in the proximal position, rotation of the corresponding output gear <NUM>, <NUM>, or <NUM> drives a corresponding rotation of the selected coupling shaft <NUM>, <NUM>, or <NUM> and, in turn, drives a rotation of the corresponding output shaft <NUM>, <NUM>, or <NUM>. On the other hand, when the selected coupling shaft <NUM>, <NUM>, or <NUM> is in the distal position, the gear <NUM> of the selected coupling shaft <NUM>, <NUM>, or <NUM> is disengaged from the geared inner surface <NUM> of the respective output gear <NUM>, <NUM>, or <NUM> so that rotation of the output gear <NUM>, <NUM>, <NUM> does not result in a concomitant rotation of the coupling shaft <NUM>, <NUM>, <NUM> or the output shaft <NUM>, <NUM>, <NUM>.

With continued reference to <FIG>, the selector cam <NUM> of the transmission assembly <NUM> is operably coupled to the selector motor <NUM> and is configured to maintain only one of the coupling shafts <NUM>, <NUM>, or <NUM> in operable engagement with the main drive motor <NUM> at a time. The selector motor <NUM> may be an electric stepper motor and rotatably supports a gear <NUM>. The selector cam <NUM> has a generally arcuate shape and is disposed about the main drive motor <NUM>. The selector cam <NUM> has an outer circumferential edge <NUM> having a plurality of teeth <NUM> in meshing engagement with the gear <NUM> of the selector motor <NUM> such that actuation of the selector motor <NUM> moves the selector cam <NUM> about the main drive motor <NUM> between a plurality of discrete positions.

As best shown in <FIG>, the selector cam <NUM> has a distal-facing surface <NUM> engaged with the proximal end portion 150a of each of the coupling shafts <NUM>, <NUM>, <NUM>. The distal-facing surface <NUM> of the selector cam <NUM> has opposing first and second ramped end portions 172a, 172b and a recess <NUM> disposed centrally between the first and second ramped end portions 172a, 172b. The recess <NUM> is defined by a pair of ramped segments 174a, 174b of the distal-facing surface <NUM>. The selector cam <NUM>, in response to an actuation of the selector motor <NUM>, is configured to move along an arcuate path between a first position (<FIG>), a second position, and a third position (e.g., as illustrated by double-headed arrows of <FIG> and <FIG>).

When the selector cam <NUM> is in the first position, the first or central coupling shaft <NUM> is aligned with the recess <NUM> and therefore in the proximal position, and the second and third coupling shafts <NUM>, <NUM> are maintained in the distal position by the distal-facing surface <NUM> of the selector cam <NUM>. When the selector cam <NUM> is in the second position (not explicitly shown), the second coupling shaft <NUM> is disposed out of alignment with the distal-facing surface <NUM> of the selector cam <NUM> and therefore in the proximal position, and the first and third coupling shafts <NUM>, <NUM> are maintained in the distal position by the distal-facing surface <NUM>. When the selector cam <NUM> is in the third position (not explicitly shown), the third coupling shaft <NUM> is out of alignment with the distal-facing surface <NUM> and therefore in the proximal position, and the first and second coupling shafts <NUM>, <NUM> are maintained in the distal position by the distal-facing surface <NUM>.

With brief reference to <FIG>, the transmission assembly <NUM> may further include a bracket <NUM> disposed about each of the output shafts <NUM>, <NUM>, <NUM> and fixed within the transmission housing <NUM>. The bracket <NUM> defines a plurality of apertures <NUM> configured for receipt of the tab <NUM> of the respective coupling shafts <NUM>, <NUM>, <NUM> when the coupling shafts <NUM>, <NUM>, <NUM> are in the distal position. With the tab <NUM> of each the coupling shafts <NUM>, <NUM>, <NUM> received in the respective aperture <NUM> of the bracket <NUM>, inadvertent rotation of the coupling shafts <NUM>, <NUM>, <NUM>, and therefore the respective output shafts <NUM>, <NUM>, <NUM>, is resisted.

In operation, a user may manually select the desired function of the end effector to be carried out by the handle assembly <NUM>. For example, a user may desire for an opening/closing of the attached end effector. The processor <NUM> (<FIG>) of the handle assembly <NUM> translates this command into an appropriate operation of the first or central output shaft <NUM> of the transmission assembly <NUM>. To enable operation of the first output shaft <NUM>, the processor <NUM> actuates the selector motor <NUM> to move the selector cam <NUM> into the first position, as shown in <FIG>. As the selector cam <NUM> is moved toward the first position, in response to an activation of the selector motor <NUM>, the recess <NUM> in the distal-facing surface <NUM> of the selector cam <NUM> moves into alignment with the first coupling shaft <NUM> of the transmission assembly <NUM> whereby the resilient bias of the biasing member <NUM> is allowed to drive the first coupling shaft <NUM> into the proximal position. In the proximal position, the proximal end portion 150a of the first coupling shaft <NUM> is received in the recess <NUM> of the selector cam <NUM>. With the selector cam <NUM> in the first position, the second and third coupling shafts <NUM>, <NUM> are maintained in their distal positions by the distal-facing surface <NUM> of the selector cam <NUM>.

With the selector cam <NUM> in the selected first position, the handle assembly <NUM> may generate an indication (e.g., an auditory or visual indication) to the user that the handle assembly <NUM> is ready to be actuated to perform the desired function. A user may then actuate the fire switch <NUM> (<FIG>) of the handle assembly <NUM>, whereby the main drive motor <NUM> drives a rotation of the main drive gear <NUM>, which drives a concomitant rotation of each of the output gears <NUM>, <NUM>, <NUM>. However, since only the first coupling shaft <NUM> of the plurality of coupling shafts <NUM>, <NUM>, <NUM> is in the proximal position with the selector cam <NUM> being set in the first position, only the first coupling shaft <NUM> is operably engaged with the main drive gear <NUM>. In particular, the gear <NUM> (<FIG>) of the first coupling shaft <NUM> is in meshing engagement with the geared inner surface <NUM> of the first output gear <NUM> such that the rotation of the first output gear <NUM> results in rotation of the first coupling shaft <NUM> and, in turn, rotation of the first output shaft <NUM>. In contrast, the second and third output shafts <NUM>, <NUM> remain stationary given that the gear <NUM> of the respective second and third coupling shafts <NUM>, <NUM> is distal and out of engagement with the respective second and third output gears <NUM>, <NUM>.

If a user desires that another type of function of the end effector be carried out by the handle assembly <NUM>, the selector cam <NUM> may be moved to the corresponding position, for example, the second position. As the selector cam <NUM> is moved from the first position to the second position (e.g., as illustrated by double-headed arrows of <FIG> and <FIG>), the ramped segment 174a of the distal-facing surface <NUM> of the selector cam <NUM> distally drives the first coupling member <NUM> from the proximal position toward the distal position against the resilient bias of the biasing member <NUM> (e.g., as illustrated by double headed arrow of <FIG>). With the selector cam <NUM> in the second position, the distal-facing surface <NUM> of the selector cam <NUM> maintains the third coupling member <NUM> in the distal position. Simultaneously, the distal-facing surface <NUM> of the selector cam <NUM> moves out of alignment with the second coupling member <NUM> (e.g., the selector cam <NUM> is disengaged from the second coupling member <NUM>) to allow the second coupling member <NUM> to move to the proximal position in which the gear <NUM> of the second coupling member <NUM> engages the geared inner surface <NUM> of the second output gear <NUM>. In this configuration, an activation of the main drive motor <NUM> ultimately results in the rotation of only the second output shaft <NUM> among the plurality of output shafts <NUM>, <NUM>, <NUM>.

Any of the components described herein may be fabricated from either metals, plastics, resins, composites or the like taking into consideration strength, durability, wearability, weight, resistance to corrosion, ease of manufacturing, cost of manufacturing, and the like.

Claim 1:
A transmission assembly (<NUM>) for use in a hand-held surgical instrument, the transmission assembly comprising:
a housing (<NUM>);
a main drive motor (<NUM>) supporting a main drive gear (<NUM>);
first and second output gears (<NUM>, <NUM>) operably coupled to the main drive gear and configured to rotate in response to a rotation of the main drive gear;
first and second output shafts (<NUM>, <NUM>) rotatably supported in the housing; and
a selector cam (<NUM>) associated with the first and second output shafts, wherein the selector cam is configured to move between a first position, in which the selector cam non-rotatably couples the first output shaft to the first output gear and the second output gear is rotatable relative to the second output shaft, and a second position, in which the selector cam non-rotatably couples the second output shaft to the second output gear and the first output gear is rotatable relative to the first output shaft, further comprising:
a first coupling shaft (<NUM>) non-rotatably coupled to the first output shaft, wherein the first coupling shaft is configured to non-rotatably engage the first output gear when the selector cam is in the first position such that only the first output shaft of the first and second output shafts rotates in response to the rotation of the main drive gear; and
a second coupling shaft (<NUM>) non-rotatably coupled to the second output shaft, wherein the second coupling shaft is configured to non-rotatably engage the second output gear when the selector cam is in the second position such that only the second output shaft of the first and second output shafts rotates in response to the rotation of the main drive gear, wherein each of the coupling shafts (<NUM>, <NUM>) has a tab or protrusion (<NUM>) that extends through a slit (<NUM>) defined in each of the output shafts such that the first and second output shafts (<NUM>, <NUM>) rotate with and by a rotation of the respective first and second coupling shafts (<NUM>, <NUM>); and
characterised in that the transmission assembly further includes a bracket (<NUM>) disposed about each of the output shafts (<NUM>, <NUM>) and fixed within the housing (<NUM>), the bracket defining a plurality of apertures (<NUM>) configured for receipt of the tab of the respective coupling shaft when the coupling shaft is in a distal position.