Patent Description:
Manually-operated surgical instruments often included a handle assembly for actuating the functions of the surgical instrument. However, when using a robotic surgical system, no handle assembly was typically present to actuate the functions of the end effector. Accordingly, to use each unique surgical instrument with a robotic surgical system, an instrument drive unit was used to interface with the selected surgical instrument to drive operations of the surgical instrument.

The instrument drive unit was typically coupled to the robotic arm via a slide. The slide allowed the instrument drive unit and the attached surgical instrument to move along an axis of the slide, providing a means for adjusting the axial position of the end effector of the surgical instrument. Relevant prior art can be found in <CIT>, <CIT>, <CIT>, <CIT> and <CIT>.

In accordance with an aspect of the present disclosure, an instrument drive unit for use in a robotic surgical system is provided and includes a carriage configured to be coupled to a robotic arm, a plurality of drive shafts rotationally supported in the carriage, a plurality of electric motors disposed about the plurality of drive shafts, and a plurality of drive gears. Each electric motor includes a stator and a rotor disposed within the stator. Each drive gear is fixed to a corresponding drive shaft and is configured for interfacing with a corresponding driven member of the electromechanical surgical instrument. Each rotor is configured to rotate a corresponding drive gear in response to an activation of a respective electric motor to actuate a function of the electromechanical surgical instrument.

In aspects, each stator may be fixed relative to the carriage, and each rotor may be rotatable relative to and within a corresponding stator.

In other aspects, the electrical motors may be vertically stacked within the carriage.

In some aspects, the instrument drive unit may further include a sleeve rotationally coupled to a distal end portion of the carriage. The sleeve may be configured to non-rotationally retain the electromechanical surgical instrument.

In an aspect, the instrument drive unit may include a drive motor having a stator fixed within the carriage, and a rotor disposed within the stator of the drive motor and non-rotatably coupled to the sleeve. The rotor of the drive motor may be configured to rotate the sleeve about a central longitudinal axis defined by the carriage.

In aspects, the instrument drive unit may further include a plurality of ring gears. Each ring gear may be fixed to a corresponding rotor and operably coupled to a corresponding drive gear.

In some aspects, each ring gear may be concentrically disposed within a corresponding rotor, such that rotation of the rotor results in a rotation of the corresponding ring gear.

In other aspects, the ring gears may be vertically stacked within the electric motors.

In an aspect, a first electric motor, a first ring gear, and a first drive gear may be operably coupled to one another and aligned along a first plane.

In aspects, a second electric motor, a second ring gear, and a second drive gear may be operably coupled to one another and aligned along a second plane, vertically displaced from the first plane.

In some aspects, the ring gears may be independently rotatable relative to one another.

In other aspects, a first ring gear may have gear teeth on an inner periphery thereof. The gear teeth on the inner periphery of the first ring gear may interface with a corresponding drive gear, and an outer periphery of the first ring gear may be attached to an inner periphery of a corresponding rotor.

In an aspect, the drive gears may be vertically offset from one another.

In aspects, each drive shaft may have a distal end portion configured for interfacing with a corresponding driven member of the electromechanical surgical instrument.

In some aspects, each drive shaft may have a series of idler gears rotatably disposed thereabout and vertically offset from one another. The series of idler gears may interface with a corresponding ring gear to stabilize the drive shafts within the electric motors.

In another aspect of the present disclosure, an instrument drive unit for use in a robotic surgical system is provided and includes a carriage configured to be coupled to a robotic arm, a plurality of electric motors supported in the carriage, and a plurality of drive shafts disposed within the plurality of electric motors. Each electric motor includes a stator and a rotor disposed within the stator. The drive shafts are configured for interfacing with a corresponding driven member of an electromechanical surgical instrument. Each drive shaft has a drive gear fixed thereabout. The drive gears are disposed at a discrete vertical location relative to one another. Each rotor is configured to rotate a corresponding drive gear in response to an activation of a respective electric motor of the plurality of electric motors to actuate a function of the electromechanical surgical instrument.

In some aspects, the instrument drive unit may further include a plurality of vertically stacked ring gears. Each ring gear is fixed to a corresponding rotor and operably coupled to a corresponding drive gear, such that each rotor is configured to rotate a corresponding drive gear in response to an activation of a respective electric motor of the plurality of electric motors to actuate a function of the electromechanical surgical instrument.

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

Embodiments of the presently disclosed surgical robotic system and instrument drive units thereof 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 robotic system or component thereof that is closest to the patient, while the term "proximal" refers to that portion of the surgical robotic system or component thereof further from the patient. As used herein, the term "vertical" refers to a direction defined along a longitudinal axis of a portion of the surgical robotic system, while the term "horizontal" refers to a direction defined along a transverse axis of a portion of the surgical robotic system.

As will be described in detail below, provided is an instrument drive unit of a surgical robotic system configured to allow for a bottom-loading of a surgical instrument. The instrument drive unit has a plurality of drive shafts each configured to be coupled to a corresponding driven member of the surgical instrument for carrying out a discrete function of the surgical instrument. The drive shafts of the instrument drive unit are operably coupled to a discrete electric motor of the instrument drive unit via a discrete transmission assembly. The configuration of the transmission assemblies allows for a reduction in the overall height of the instrument drive unit (e.g., the instrument drive unit is more compact). For example, gears of the transmission assemblies are vertically and horizontally offset from the gears of the other transmission assemblies. Other features and benefits of the disclosed instrument drive units are further detailed below.

Referring initially to <FIG>, a surgical system, such as, for example, a surgical robotic system <NUM>, generally includes a plurality of surgical robotic arms <NUM>, <NUM>; an elongated slide <NUM> coupled to an end of each of the robotic arms <NUM>, <NUM>; an instrument drive unit <NUM> and an electromechanical instrument <NUM> removably attached to the slide <NUM> and configured to move along the slide <NUM>; a control device <NUM>; and an operating console <NUM> coupled with control device <NUM>. The operating console <NUM> includes a display device <NUM>, which is set up in particular to display three-dimensional images; and manual input devices <NUM>, <NUM>, by means of which a person (not shown), for example a surgeon, is able to telemanipulate robotic arms <NUM>, <NUM> in a first operating mode, as known in principle to a person skilled in the art.

Each of the robotic arms <NUM>, <NUM> may be composed of a plurality of members, which are connected through joints. Robotic arms <NUM>, <NUM> may be driven by electric drives (not shown) that are connected to control device <NUM>. Control device <NUM> (e.g., a computer) is set up to activate the drives, in particular by means of a computer program, in such a way that robotic arms <NUM>, <NUM>, the attached instrument drive units <NUM>, and thus electromechanical instrument <NUM> execute a desired movement according to a movement defined by means of manual input devices <NUM>, <NUM>. Control device <NUM> may also be set up in such a way that it regulates the movement of the instrument drive unit <NUM> along the slide <NUM>, movement of the robotic arms <NUM>, <NUM>, and/or movement of the drives.

Surgical robotic system <NUM> is configured for use on a patient "P" lying on a surgical table "ST" to be treated in a minimally invasive manner by means of a surgical instrument, e.g., electromechanical instrument <NUM>. Surgical robotic system <NUM> may also include more than two robotic arms <NUM>, <NUM>, the additional robotic arms likewise being connected to control device <NUM> and being telemanipulatable by means of operating console <NUM>. A surgical instrument, for example, an electromechanical surgical instrument <NUM> (including an electromechanical end effector), may also be attached to the additional robotic arm.

Control device <NUM> may control a plurality of motors, e.g., motors (Motor <NUM>. n), with each motor configured to drive movement of robotic arms <NUM>, <NUM> in a plurality of directions. Further, control device <NUM> may control a plurality of electric motors <NUM> (<FIG>) of the instrument drive unit <NUM> to drive various operations of the surgical instrument <NUM>. The instrument drive unit <NUM> transfers power and actuation forces from its motors to driven members (not shown) of the electromechanical instrument <NUM> to ultimately drive movement of components of the end effector of the electromechanical instrument <NUM>, for example, a movement of a knife blade (not shown) and/or a closing and opening of jaw members of the end effector.

For a detailed description of the construction and operation of a robotic surgical system, reference may be made to <CIT>, entitled "Medical Workstation,".

With reference to <FIG>, the instrument drive unit <NUM> will now be described in detail. The instrument drive unit <NUM> includes a carriage <NUM> and a coupling or sleeve <NUM> rotatably coupled to a distal end portion 26b of the carriage <NUM> for connecting a surgical instrument <NUM> (<FIG>) to the instrument drive unit <NUM>. The carriage <NUM> of the instrument drive unit <NUM> is configured to be slidably coupled to a linear track (not shown) defined longitudinally along the slide <NUM> (<FIG>). A proximal end portion 26a of the carriage <NUM> houses a plurality of electric motors 22a, 22b, 22c, 22d, 22d, 22e (collectively referred to herein as "<NUM>") for carrying out various functions of an attached surgical instrument <NUM>.

The electric motors <NUM> of the instrument drive unit <NUM> are concealed within the carriage <NUM>. The electric motors <NUM> are vertically stacked on one another and are independently actuatable via the control device <NUM> (<FIG>). One of the electric motors, such as, for example, the fifth electric motor 22e, is configured to effectuate a rotation of the surgical instrument <NUM> when the surgical instrument <NUM> is coupled to the instrument drive unit <NUM>, and the remaining electric motors 22a, 22b, 22c, 22d are configured to actuate functions of the surgical instrument <NUM>, as will be described. The electric motors <NUM> are integrated AC motors. In embodiments, the electric motors <NUM> may be any suitable type of electric motor such as an AC brushless motor, a DC brushed motor, a DC brushless motor, a direct drive motor, a servo motor, a stepper motor, or the like. It is contemplated, and within the scope of the present disclosure, that electric motors <NUM> are in the form of hollow core motors, or the like. Other types of motors are also contemplated. While the instrument drive unit <NUM> is illustrated as having five electric motors, it is contemplated that the instrument drive unit <NUM> may have more or less than five electric motors. The electric motors <NUM> are interlinked, thereby providing an infinite range of motion along the longitudinal axis "X" of the instrument drive unit <NUM>.

The electric motors <NUM> each have a stator 40a, 40b, 40c, 40d, 40e (collectively referred to herein as "<NUM>") fixed within the carriage <NUM>, and a rotor <NUM> (only rotors 42a, 42d are illustrated) rotationally disposed within a corresponding stator <NUM>. Each of the stators <NUM> may be annularly shaped and stacked on top of one another to form a hollow cylinder, as best shown in <FIG>. The stators <NUM> may be configured to receive an electric current from a power source (not explicitly shown) to produce a rotating magnetic field that drives a rotation of the rotors <NUM>.

Each of the rotors <NUM> may be configured as a permanent magnetic, an electromagnet, or any other suitable conductor. The rotors <NUM> are vertically stacked within the hollow cylinder formed by the stators <NUM> and are independently rotatable relative to one another about a central longitudinal axis "X" defined by the motors <NUM>.

With continued reference to <FIG>, the instrument drive unit <NUM> further includes a plurality of ring gears 62a, 62d, a plurality of drive gears 64a, 64b, 64c, 64d (collectively referred to herein as "<NUM>"), and a plurality of drive shafts 66a, 66b, 66c, 66d (collectively referred to herein as "<NUM>"). While only ring gears 62a and 62d are illustrated, the instrument drive unit <NUM> has four ring gears for coupling the four drive gears <NUM> and the corresponding four rotors <NUM>.

The ring gears 62a, 62d are vertically stacked within the motors <NUM>. In particular, the ring gears 62a, 62d are coaxial along the central longitudinal axis "X" defined by the motors <NUM>. As best shown in <FIG>, each of the ring gears 62a, 62d has an outer periphery <NUM> adhered to an inner periphery <NUM> of a respective rotor <NUM>, such that each ring gear and rotor pair (e.g., ring gear 62a and rotor 42a) rotate together relative to the corresponding stator 40a. Each ring gear 62a, 62d has gear teeth <NUM> extending from an inner periphery <NUM> thereof. The gear teeth <NUM> on the inner periphery <NUM> of each of the ring gears 62a, 62d interfaces with a corresponding drive gear <NUM>, as will be described. In embodiments, each of the rings gears 62a, 62d may be constructed as a rotor <NUM> rather than being integrally connected with a rotor <NUM>.

The drive shafts 66a, 66b, 66c, 66d extend longitudinally through the motors <NUM> and distally therefrom. The drive shafts <NUM> each have a distal end portion configured to operably couple to a driven member (not explicitly shown) of the surgical instrument <NUM>. For example, the distal end portion of each of the drive shafts <NUM> may have a coupler (e.g., a gear) for coupling with a corresponding coupler of a driven member of the surgical instrument <NUM>. Accordingly, upon bottom-loading of the electromechanical instrument <NUM> into the instrument drive unit <NUM>, the distal end portions of the drive shafts <NUM> of the instrument drive unit <NUM> operably couple to the gears/couplers in a distal end of the main body portion (not shown) of the electromechanical instrument <NUM>, such that a rotation of each drive shaft <NUM> rotates a correspondingly coupled driven member of the surgical instrument <NUM> to effectuate a discrete function of the surgical instrument (e.g., opening/closing of the end effector, articulation of the end effector, etc.).

The drive shafts <NUM> each have a drive gear <NUM> such as, for example, a spur gear, rotationally fixed thereabout. Each of the drive gears <NUM> are positioned at a discrete vertical location on their respective drive shaft <NUM>, such that the drive gears <NUM> are vertically offset a selected distance from one another. Since the drive gears <NUM>, in addition to being vertically offset, are also circumferentially spaced from one another, the drive gears <NUM> are offset from one another in all three dimensions. As mentioned above, the drive gears <NUM> each interface or intermesh with the gear teeth <NUM> on the inner periphery <NUM> of a corresponding ring gear <NUM> and receive torque therefrom originating from the respective rotor <NUM>.

Each of the drive shafts <NUM> may have a nut 74a, 74b, 74c, 74d (collectively referred to herein as "<NUM>") fixed thereabout. The nuts <NUM> are disposed adjacent a corresponding drive gear <NUM> and fixed thereto, thereby fixedly coupling the drive gears <NUM> to the drive shafts <NUM>. Each drive shaft <NUM> may further include a series of idler gears <NUM> rotatably disposed thereabout and vertically offset from one another. The series of idler gears <NUM> on each drive shaft <NUM> interface with a corresponding ring gear <NUM> to stabilize the plurality of drive shafts <NUM> within the plurality of electric motors <NUM>.

In operation, the electromechanical instrument <NUM> is coupled to the instrument drive unit <NUM> by passing the main body portion of the electromechanical instrument <NUM> through the sleeve <NUM> of the instrument drive unit <NUM> in a proximal direction. With the main body portion of the electromechanical instrument <NUM> attached to the sleeve <NUM> of the instrument drive unit <NUM>, the distal end portion of each of the drive shafts <NUM> interfaces with corresponding gears/couplers (not shown) in the proximal end of the main body portion of the electromechanical instrument <NUM>.

With the electromechanical instrument <NUM> coupled to the instrument drive unit <NUM>, to actuate a particular function of the surgical instrument <NUM>, such as, for example, an opening or closing of an end effector of the surgical instrument <NUM>, one of the electric motors <NUM> of the instrument drive unit <NUM>, such as the first electric motor 22a, is activated via the control device <NUM> (<FIG>). An activation of the first electric motor 22a includes supplying an electric current to the stator 40a thereof, which drives a rotation of the rotor 42a thereof. It is contemplated that the control device <NUM> or a processor (not shown) of the electric motor 22a generates a rotating magnetic field about the stator 40a to drive the rotation of the rotor 42a.

The first ring gear 62a rotates with the rotor 42a, which, in turn, rotates the first drive gear 64a. Since the first drive gear 64a is rotationally fixed about the first drive shaft 66a, and the distal end portion of the first drive shaft 66a is operably coupled to the proximal end of the first driven member of the surgical instrument <NUM> (<FIG>), a rotation of the first drive gear 64a causes the first drive shaft 66a to rotate, thereby rotating the first driven member of the electromechanical instrument <NUM> to actuate an associated function of the surgical instrument <NUM>.

To rotate the electromechanical instrument <NUM> about its longitudinal axis, the fifth electric motor 22e of the instrument drive unit <NUM> is activated by the control device <NUM> (<FIG>). An activation of the fifth electric motor 22e includes supplying an electric current to the stator 40e thereof, which drives a rotation of the rotor 42e thereof. Rotation of the rotor 42e rotates the sleeve <NUM>. Given that the electromechanical instrument <NUM> is non-rotationally supported in the sleeve <NUM>, the electromechanical instrument <NUM> rotates with the sleeve <NUM> relative to the carriage <NUM> to change a rotational orientation of the electromechanical instrument <NUM>.

The drive motors 22a, 22b, 22c, 22d may be configured to concurrently rotate the rotors 42a, 42b, 42c, 42d, and in turn the drive gears 64a, 64b, 64c, 64d, with the sleeve <NUM> rotation. This would prevent rotation of the drive shafts 66a, 66b, 66c, 66d relative to the ring gears 62a, 62b, 62c, 62d during rotation of the sleeve <NUM>, which may otherwise occur if the drive gears 64a, 64b, 64c, 64d were allowed to rotate relative to the ring gears 62a, 62b, 62c, 62d during rotation of the sleeve <NUM>. Conversely, the fifth motor 22e may be configured to counteract any torque output by the other four drive motors 22a, 22b, 22c, 22d to prevent the inadvertent rotation of the sleeve <NUM>.

As can be appreciated, the instrument drive unit <NUM> described above improves usability of the surgical robotic system <NUM>, reduces a foot-print of the overall system <NUM>, improves safety architecture, reduces the time required to remove surgical instruments in case of an emergency, and simplifies the electronics used in the instrument drive unit <NUM>.

Claim 1:
An instrument drive unit for use in a robotic surgical system, the instrument drive unit comprising:
a carriage configured to be coupled to a robotic arm;
a plurality of drive shafts rotationally supported in the carriage;
a plurality of electric motors disposed about the plurality of drive shafts, each electric motor of the plurality of electric motors including a stator and a rotor disposed within the stator; and
a plurality of drive gears, each drive gear of the plurality of drive gears fixed to a corresponding drive shaft of the plurality of drive shafts and configured for interfacing with a corresponding driven member of the electromechanical surgical instrument, wherein each rotor is configured to rotate a corresponding drive gear of the plurality of drive gears in response to an activation of a respective electric motor of the plurality of electric motors to actuate a function of the electromechanical surgical instrument wherein each stator is fixed relative to the carriage, and each rotor is rotatable relative to and within a corresponding stator characterized in that the plurality of electrical motors are vertically stacked within the carriage, and
further comprising a plurality of ring gears, each ring gear of the plurality of ring gears fixed to a corresponding rotor and operably coupled to a corresponding drive gear of the plurality of drive gears wherein each ring gear of the plurality of ring gears is concentrically disposed within a corresponding rotor, such that rotation of the rotor results in a rotation of the corresponding ring gear of the plurality of ring gears wherein the plurality of ring gears are vertically stacked within the plurality of electric motors.