Patent Description:
Delivery systems and methods for delivering a material to a target site are known in the art. One such delivery system comprises a printhead having a plurality of nozzles through which material is delivered to a target site. A robotic arm positions the printhead relative to the target site. The printhead delivers the material to the target site through the nozzles when the printhead is in position.

Another delivery system comprises a delivery device adapted to dispense a biological material onto a target site. A positioning system positions the target site and the delivery device with respect to one another. A ribbon contains the biological material to be delivered to the target site. The delivery device emits a laser that delivers the biological material from the ribbon onto the target site.

During a medical procedure, however, there is a need in the art to track a position of a target site on a patient as well as to track a position of a delivery device and maintain the position of the delivery device in relation to the target site in order to accommodate movement of the patient during the medical procedure so that the material is delivered in desired patterns, flow rates, and the like with respect to the target site.

Document <CIT> is directed to a system and method for shaping an anatomical component having an existing shape and a desired reconstructed shape. The system includes an applicator for depositing material on the anatomical component and a controller in communication with the applicator, the controller controlling the deposition of material by the applicator based on a relationship between the applicator and the existing shape of the anatomical component to create the desired reconstructed shape.

Document <CIT> describes a tool including a housing having a receiving portion configured to receive at least a portion of an operating member so as to permit rotation of the operating member relative to the housing while constraining movement of the operating member in a radial direction of the operating member. The tool also includes a coupling device disposed on the housing and configured to couple the operating member to the housing so as to permit rotation of the operating member relative to the housing. The coupling device includes a retaining member configured to engage the operating member to constrain movement of the operating member relative to the housing in a longitudinal direction of the operating member. The retaining member is configured to rotate relative to the housing.

Document <CIT> relates to a surgical instrument for treating tissue during a medical procedure. The instrument includes a hand-held portion and a working portion. The hand-held portion is manually supported and moved by a user and the working portion is movably coupled to the hand-held portion. A tracking device is attached to the hand-held portion for tracking the instrument. The tracking device is in communication with a control system, which is used to keep the working portion within or outside of a boundary. A plurality of actuators are operatively coupled to the working portion. The control system instructs the actuators to move the working portion relative to the hand-held portion during the medical procedure in order to maintain a desired relationship between the working portion and the boundary.

According to claim <NUM>, a system for delivering material to a target site comprises a delivery device having an opening and being configured to deliver the material to the target site through the opening. A navigation system is configured to track the delivery device and the target site and to generate position signals. A controller is in communication with the delivery device and the navigation system and is configured to define a virtual boundary associated with the target site and to control movement of the opening with respect to the virtual boundary based on the position signals from the navigation system. The controller of the system of claim <NUM> is further configured to actuate the distal end tip to move away from the virtual boundary in response to detecting an attempt to move the delivery instrument or distal end tip beyond the virtual boundary.

One exemplary embodiment of a delivery system for delivering material to a target site defined by a virtual boundary is provided. The delivery system comprises a delivery device having an opening for delivering the material to the target site. A grasping portion is fixed relative to the opening for being grasped by an operator to move the opening with respect to the target site. A navigation system is configured to track the delivery device and the target site and to generate position signals. A controller is in electrical communication with the navigation system. A material supply device supplies the material to the delivery device and is in electrical communication with the controller to control a rate at which the material is delivered to the target site by the delivery device based on the position signals from the navigation system.

One exemplary embodiment of a method for delivering material through an opening of a delivery device to a target site defined by a virtual boundary is provided. The method comprises the step of delivering the material to the target site through the opening. The delivery device and the target site are tracked to generate position signals. Movement of the opening is controlled with respect to the virtual boundary based on the position signals while delivering the material to the target site.

Another exemplary embodiment of a method for delivering material through an opening of a delivery device to a target site defined by a virtual boundary is provided. The method comprises the step of delivering the material to the target site through the opening. The delivery device and the target site are tracked to generate position signals. A flow rate of the material is controlled based on the position signals while delivering the material to the target site.

One advantage of these embodiments is the ability to track both the delivery device and the virtual boundary and control movement of the opening with respect to the target site and/or control the flow rate of the material based on the position signals from the navigation system while delivering the material to the target site. Likewise, the material being delivered can also be tracked. Furthermore, the virtual boundary provides accurate delivery of the material to the target site by constraining the delivery device, the opening, and/or the material within the virtual boundary. The delivery systems and methods described herein may provide other embodiments not specifically recited herein.

Referring to the Figures, wherein like numerals indicate like or corresponding parts throughout the several views, a delivery system is shown generally at <NUM> in <FIG>.

Referring to <FIG>, the delivery system <NUM>, according to one embodiment, includes a delivery instrument <NUM>, a delivery device <NUM>, a plurality of actuators <NUM>, <NUM>, <NUM>, e.g. motors, a navigation (localization) system <NUM>, a controller <NUM>, and a material supply system <NUM>. The navigation system <NUM> tracks the delivery device <NUM> to keep a distal end tip <NUM> of the delivery device <NUM> in a desired relationship to a virtual bo1.1ndary <NUM> (herein "distal" means away from an operator supporting the delivery device <NUM> and toward the virtual boundary <NUM>). A target site <NUM> of a patient is defined by the virtual boundary <NUM>. The delivery instrument <NUM> in <FIG> is a hand-held device to be grasped by the operator. The delivery instrument <NUM> may communicate wirelessly with any of the navigation system <NUM>, controller <NUM>, and material supply system <NUM>. Alternatively, the delivery instrument <NUM> may be wired to any of the same.

In the embodiment shown, the virtual boundary <NUM> defines a location to which a material should be delivered. The location may be a <NUM>-D space to be at least partially or fully filled with a material, or the location may be a path with respect to which the material should be delivered. The virtual boundary <NUM> may be defined by any shape or size and may include <NUM>-D or <NUM>-D shapes, lines, trajectories, surfaces, linear paths, non-linear paths, volumes, planes, bore holes, contours, and the like. In some embodiments the virtual boundary <NUM> can define a <NUM>-D or <NUM>-D boundary across which the distal end tip <NUM> should not cross. In other embodiments the virtual boundary <NUM> may define a line, path, trajectory, or course along which the distal end tip <NUM> should travel. In these cases, the virtual boundary <NUM> is also referred to as a target path, target trajectory, or target course.

The virtual boundary <NUM> may be defined with respect to a CT scan, MRI, or other image of the target site. The virtual boundary <NUM> may thus be defined with respect to a coordinate system of the associated image. Coordinates defining the virtual boundary <NUM> can then be later transformed into other coordinate systems, as desired, using conventional navigation and transformation methods. In one embodiment, the virtual boundary <NUM> is generated by and/or implemented by the controller <NUM>. The CT scan, MRI, or other modality may provide a <NUM>-D model of the patient's anatomy and the target site with the virtual boundary <NUM> being defined as a surface within the <NUM>-D model, a volume in the <NUM>-D model using voxels, or the virtual boundary <NUM> may be defined using other methods.

The material to be delivered may be any material capable of being delivered, including materials delivered in a flowable condition, such as viscous materials, rigid particles carried in a flowable medium, and the like. The materials may include biological agents, drugs, flowable materials capable of setting to a hardened condition such as soft tissue cements and gels, bone cements, bio-gels, other therapeutic materials, and the like.

In one embodiment, the controller <NUM> controls the plurality of actuators <NUM>, <NUM>, <NUM> to move the distal end tip <NUM> relative to the target site <NUM>. This control locates the distal end tip <NUM> at a desired location with respect to the virtual boundary <NUM> to deliver the material in a desired manner. Different control methods for locating the distal end tip <NUM> at various locations with respect to the virtual boundary <NUM> are described further below.

Referring to <FIG>, the delivery device <NUM> includes a delivery conduit <NUM> that extends from a proximal end to the distal end tip <NUM>. The delivery conduit <NUM> defines an opening <NUM> at the distal end tip <NUM> through which the material exits the delivery conduit <NUM> to reach the target site <NUM>. For simplicity, the material may be understood to exit the distal end tip <NUM>, the opening <NUM>, and/or the delivery device <NUM> generally. Furthermore, because the opening <NUM> is provided at the distal end tip <NUM>, these terms in some instances may be interchangeable. The proximal end of the delivery conduit <NUM> is removably attachable to the delivery instrument <NUM>. The proximal end of the delivery conduit <NUM> may be removably attached to the delivery instrument <NUM> using a bayonet connection, a threaded coupling, or other connection. The delivery conduit <NUM> may be a delivery tube, nozzle, and the like. A port may be integrated into the delivery device <NUM> through which the material may be delivered to the delivery device <NUM> from the material supply system <NUM>.

In this embodiment, the delivery instrument <NUM> has a grasping portion <NUM>. The delivery instrument <NUM> also includes the one or more actuators <NUM>, <NUM>, <NUM>. The actuators <NUM>, <NUM>, <NUM> are operatively coupled to the delivery device <NUM> when the delivery device <NUM> is attached to the deliver instrument <NUM>. The actuators <NUM>, <NUM>, <NUM> are able to move the distal end tip <NUM> in at least one or more degrees of freedom, such as pitch, yaw, and/or displacement along an axis with respect to the grasping portion <NUM>.

Each actuator <NUM>, <NUM>, <NUM> can be controlled by a separate actuator controller <NUM>. In some embodiments, the actuators <NUM>, <NUM>, <NUM> can be controlled by a single actuator controller <NUM>. In one example, the actuator controllers <NUM> are wired separately to the actuators <NUM>, <NUM>, <NUM>. In some embodiments, the actuator controllers <NUM> can be proportional integral derivative (PID) controllers. In some embodiments, the actuator controllers <NUM> can be integrated with or form part of the delivery device <NUM>. A separate power source P may be in communication with the actuators <NUM>, <NUM>, <NUM> and actuator controllers <NUM>.

The delivery instrument <NUM> may be like that shown in <CIT>, entitled, "SURGICAL INSTRUMENT INCLUDING HOUSING, A CUTTING ACCESSORY THAT EXTENDS FROM THE HOUSING AND ACTUATORS THAT ESTABLISH THE POSITION OF THE CUTTING ACCESSORY RELATIVE TO THE HOUSING".

According to one embodiment, the navigation system <NUM> includes a first tracker <NUM>, a second tracker <NUM>, a camera unit <NUM> having a plurality of optical sensors <NUM>, a navigation computer <NUM>, and a display <NUM>. The first tracker <NUM> is attached to the patient such that the first tracker <NUM> is in a fixed and known position relative to the target site <NUM>. The second tracker <NUM> is attached to the delivery instrument <NUM> such that the second tracker <NUM> is in a known position relative to the distal end tip <NUM>. For example, the second tracker <NUM> is fixed relative to the grasping portion <NUM>. The navigation computer <NUM> is in electrical communication with the display <NUM>. The navigation system <NUM> may be like that described in <CIT>, entitled, "Navigation Systems and Methods for Indicating and Reducing Line-of-Sight Errors".

The camera unit <NUM> senses signals from markers (not shown) on the first tracker <NUM> and markers (not shown) on the second tracker <NUM> and sends position signals to the navigation computer <NUM> corresponding to these markers. The markers may be active markers such as infrared light emitting diodes or passive markers such as reflector bails, which are conventional in the navigation arts.

The navigation computer <NUM> interprets the position signals from the camera unit <NUM> using conventional triangulation and registration methods to determine a position and orientation of the virtual boundary <NUM> in a camera coordinate system based upon the fixed position of the virtual boundary <NUM> relative to the first tracker <NUM>.

The navigation computer <NUM> also interprets the position signals from the camera unit <NUM> to determine a position and orientation of a known "home" position of the opening <NUM> in the distal end tip <NUM> in the camera coordinate system. In one embodiment, the known "home" position of the distal end tip <NUM> relative to the tracker <NUM> is measured during manufacture and saved in memory for use by the navigation computer <NUM> and/or controller <NUM>. Encoders or other position sensors (not shown) are associated with each of the actuators <NUM>, <NUM>, <NUM>. The encoders are in communication with the actuator controllers <NUM> and the controller <NUM>. The encoders measure deviations of the opening <NUM> from this known "home" position based on predetermined relationships between actuator movement and movement of the opening <NUM>. As a result, the position and orientation of the opening <NUM> relative to the tracker <NUM> can be continuously updated. As such, the encoders may be regarded as subcomponents of the navigation system <NUM> because the encoder information may be utilized by the navigation system <NUM> to determine the positions signals related to the opening <NUM>.

The navigation computer <NUM> generates an image or images of the delivery-device <NUM> (such as an image of the distal end tip <NUM> and opening <NUM> therein), the cutting accessory <NUM>, and the target site <NUM> including the virtual boundary <NUM> that can be viewed on the display <NUM><NUM> such that the position and orientation of the delivery device <NUM>, including the distal end tip <NUM> and the position and orientation of the virtual boundary <NUM> can be viewed in substantially real time during the medical procedure.

In some embodiments the navigation computer <NUM> sends position signals to the controller <NUM>. The position signals transmit data corresponding to the position and orientation of the virtual boundary <NUM> and to the position and orientation of the distal end tip <NUM>. The controller <NUM> controls the actuators <NUM>, <NUM>, <NUM> to move the distal end tip <NUM> to ensure that the distal end tip <NUM> is located in a desired position and/or orientation with respect to the virtual boundary <NUM> based on the position signals.

Although one embodiment of the navigation system <NUM> is shown in the Figures, the navigation system <NUM> may have any other suitable configuration for tracking the position of the delivery device <NUM>, the distal end tip <NUM> and the target site <NUM>.

In one embodiment, the navigation system <NUM> is ultrasound-based. For example, the navigation system <NUM> may comprise an ultrasound imaging device coupled to the navigation computer <NUM>. The ultrasound imaging device images any of the aforementioned objects, e.g., the delivery device <NUM>, the distal end tip <NUM> and the target site <NUM> and generates position signals to the controller <NUM> based on the ultrasound images. The ultrasound images may be <NUM>-D, <NUM>-D, or a combination of both. The navigation computer <NUM> may process the images in real-time to determine coordinate positioning of the objects. Trackers <NUM>, <NUM> may be omitted in this embodiment because the ultrasound imaging device may determine position based on the ultrasound images alone. Furthermore, the ultrasound imaging device may have any suitable configuration and may be different than the camera unit <NUM> as shown in <FIG>.

In another embodiment, the navigation system <NUM> is radio frequency (RF)-based. For example, the navigation system <NUM> may comprise an RF transceiver in communication with the navigation computer <NUM>. Any of the delivery device <NUM>, the distal end tip <NUM> and the target site <NUM> may comprise RF emitters or transponders attached thereto. The RF emitters or transponders may be passive or actively energized. The RF transceiver transmits an RF tracking signal and generates position signals to the controller <NUM> based on RF signals received from the RF emitters. The navigation computer <NUM> and/or the controller <NUM> may analyze the received RF signals to associate relative positions thereto. The RF signals may be of any suitable frequency. In this embodiment, there may be no need for any such camera unit <NUM> as shown in <FIG>. The RF transceiver may be positioned at any suitable location to effectively track the objects using RF signals. Furthermore, the RF emitters or transponders may have any suitable structural configuration that may be much different than the trackers <NUM>, <NUM>, as shown in <FIG>.

In yet another embodiment, the navigation system <NUM> is electromagnetically-based. For example, the navigation system <NUM> may comprise an EM transceiver coupled to the navigation computer <NUM>. Any of the device <NUM>, the distal end tip <NUM> and the target site <NUM> may comprise EM components attached thereto, such as any suitable magnetic tracker, electo-magnetic tracker, inductive tracker, or the like. The trackers may be passive or actively energized. The EM transceiver generates an EM field and generates position signals to the controller <NUM> based EM signals received from the trackers. The navigation computer <NUM> and/or the controller <NUM> may analyze the received EM signals to associate relative positions thereto. Again, such navigation system <NUM> embodiments may have structural configurations that are different than the navigation system <NUM> configuration as shown throughout the Figures.

Those skilled in the art appreciate that the navigation system <NUM> may have any other suitable components or structure not specifically recited herein. Furthermore, any of the techniques, methods, and/or components described above with respect to the camera-based navigation system <NUM> shown throughout the Figures may be implemented or provided for any of the other embodiments of the navigation system <NUM> described herein.

Referring back to <FIG>, the grasping portion <NUM> is supported by an operator during the medical procedure to deliver the material to the target site <NUM>. The operator can induce movement of the delivery instrument <NUM> with respect to the virtual boundary <NUM>. In one embodiment, the operator induces movement of the delivery instrument <NUM> with respect to the virtual boundary <NUM> by moving the grasping portion <NUM>.

The operator can be a human operator or a robotic operator. The human operator can manually support the grasping portion <NUM> to manually move the delivery instrument <NUM>. The robotic operator can support the delivery instrument <NUM> with a robot end effector or a robot manipulator, as will be described below. The robotic operator can induce movement of the delivery instrument <NUM> with respect to the virtual boundary <NUM> in response to the position signals from the navigation computer <NUM> being sent to the controller <NUM>. In some embodiments, the grasping portion <NUM> can be manually manipulated by the human operator while the instrument <NUM> is also supported by the robotic operator.

In some embodiments, during the medical procedure, the controller <NUM> may determine it is appropriate to reposition the distal end tip <NUM> as the distal end tip <NUM> approaches, meets, or exceeds the virtual boundary <NUM>. The controller <NUM> correspondingly controls one or more of the actuators <NUM>, <NUM>, <NUM> to move the distal end tip <NUM> in the manner described in <CIT>, entitled, "SURGICAL INSTRUMENT INCLUDING HOUSING, A CUTTING ACCESSORY THAT EXTENDS FROM THE HOUSING AND ACTUATORS THAT ESTABLISH THE POSITION OF THE CUTTING ACCESSORY RELATIVE TO THE HOUSING". For example, the controller <NUM> may determine that the distal end tip <NUM> is crossing the virtual boundary <NUM> as the distal end tip <NUM> delivers the material. In response, the controller <NUM> transmits a signal to at least one of the actuator controllers <NUM> that causes one or more of the actuators <NUM>, <NUM>, <NUM> to move the distal end tip <NUM> away from the virtual boundary <NUM>.

With continued reference to <FIG>, the material supply system <NUM> includes a reservoir <NUM><NUM> and a material supply device <NUM> in communication with the reservoir <NUM>. The reservoir <NUM> contains the material to be delivered to the target site <NUM><NUM> by the delivery device <NUM>. The material supply device <NUM> may be a pump or other mechanism for conveying the material from the reservoir <NUM> to the delivery device <NUM>. The material supply system <NUM> includes supply lines connecting the reservoir <NUM> to the material supply device <NUM> and connecting the material supply device <NUM> to the port on the delivery device <NUM>. The material supply device <NUM> is in electrical communication with the controller <NUM>.

The material supply device <NUM> moves the material to the distal end tip <NUM> for delivery to the target site <NUM>. In some embodiments the controller <NUM> controls a flow rate at which the material supply device <NUM> moves the material to the target site <NUM>. The controller <NUM> can control the flow rate when the distal end tip <NUM> approaches, meets, or exceeds the virtual boundary <NUM>. For example, the controller <NUM> may determine that the distal end tip <NUM> is crossing the virtual boundary <NUM> as the distal end tip <NUM> delivers the material. In response, the controller <NUM> transmits a signal to the material supply device <NUM> that causes the flow rate to slow or stop. Although not shown, a variable orifice valve or other type of valve may also be located adjacent to the distal end tip <NUM> to control the flow of material.

Referring to <FIG> and <FIG>, in one embodiment, a cutting accessory <NUM> is first removably attached to the delivery instrument <NUM> so that the tissue can be removed to define the target site <NUM> prior to delivering the material to the target site <NUM>. The cutting accessory <NUM> may include a distal end tip <NUM> having any suitable configuration, such as a cutting bur, ultrasonic tip, saw, or other accessory or energy applicator suitable for removing tissue. The distal end tip <NUM> of the cutting accessory <NUM> is controlled in the same manner as the distal end tip <NUM> of the delivery device <NUM> in order to remove the tissue. An example of the cutting accessory <NUM> and the manner of controlling and moving the same is described in <CIT>, entitled, "SURGICAL INSTRUMENT INCLUDING HOUSING, A CUTTING ACCESSORY THAT EXTENDS FROM THE HOUSING AND ACTUATORS TH AT ESTABLISH THE POSITION OF THE CUTTING ACCESSORY RELATIVE TO THE HOUSING".

In one embodiment, the delivery device <NUM> is integrated into the cutting accessory <NUM>. In this case, the cutting accessory <NUM> defines a central lumen through which the material can be delivered to the target site <NUM><NUM>. As a result, removal of the cutting accessory <NUM> from the delivery instrument <NUM> and attachment of a separate delivery device <NUM> is unnecessary. This convenience may be desirable in procedures requiring quicker treatment times or in procedures in which cutting tissue and delivering material can be performed simultaneously.

The delivery instrument <NUM> may comprise any suitable mechanism for controlling motion of the delivery instrument <NUM> and/or delivery of the material to the target site <NUM><NUM>. In one embodiment, the delivery instrument <NUM> comprises a button or trigger <NUM>. The trigger <NUM> may be integrated into the delivery instrument <NUM>, as shown in <FIG>, or remotely coupled thereto. The trigger <NUM> may be in communication with any of the actuators <NUM>, <NUM>, <NUM>, the controller <NUM>, and the material supply system <NUM>. The trigger <NUM> may have several different functions. In some embodiments, the trigger <NUM> may be a multi-trigger for controlling any of the functions of the delivery instalment <NUM> described herein.

In one example, depressing and holding the trigger <NUM> causes the material to be delivered while releasing the trigger <NUM> stops delivery of material. Alternatively, pressing the trigger <NUM> once (and releasing) may start the flow of material while pressing the trigger <NUM> again (and releasing) may stop the flow of material. In either case, pressing the trigger <NUM> may enable automated control of the delivery of the material as described herein. Additionally, the delivery flow rate of the material may correspond to the extent by which the trigger <NUM> is depressed. For example, a fully depressed trigger <NUM> may cause the material to be delivered at a maximum flow rate while a partially depressed trigger <NUM> may cause the material to be delivered at a partial (less than maximum) flow rate. The human operator or the robotic operator may control the position of the trigger <NUM> as desired. Furthermore, the trigger <NUM> may allow the operator to manually control any of the actuators <NUM>, <NUM>, <NUM> for positioning the distal end tip <NUM> relative to the target site <NUM>.

Those skilled in the art appreciate that methods other than a button or trigger <NUM> may be provided to control the aforementioned functions of the delivery instrument <NUM>. For example, in one embodiment, a foot pedal may be coupled to the delivery instrument <NUM>. The operator depresses the foot pedal. Control of the delivery flow rate of the material as a result of depressing the foot pedal may be such as that described above in relation to the trigger <NUM>. For example, depressing the foot pedal and holding the pedal down causes the material to be delivered while releasing the foot pedal stops delivery of material. Alternatively, depressing the foot pedal once (and releasing) may start the flow of material while depressing the foot pedal again (and releasing) may stop the flow of material. Additionally, the delivery flow rate of the material may correspond to the extent by which the foot pedal is depressed. For example, a fully depressed foot pedal may cause the material to be delivered at a maximum flow rate while a partially foot pedal may cause the material to be delivered at a partial (less than maximum) flow rate.

The trigger <NUM> and/or foot pedal may be utilized for the hand-held instrument <NUM> or the robotic manipulator <NUM> as shown in <FIG>, and as described in detail below.

<FIG> illustrates a procedure in which a focal defect F is located in a femur of a patient. The focal defect F has an irregular shape as shown. In order to treat the focal defect F, tissue such as cartilage and/or bone is removed by the cutting accessory <NUM> so that a cleaner, better defined <NUM>-D geometric shape defines the target site <NUM>, as shown in <FIG>. Once the target site <NUM> is defined, the material is delivered from the distal end tip <NUM> of the delivery device to the target site <NUM>. In one embodiment, the material is delivered to the target site <NUM> so that a final upper surface of the material, once it sets to a hardened condition, matches the original, pre-defect shape of the articular surface of the femur. The upper surface of the hardened material is also flush with the undamaged tissue of the femur surrounding the target site <NUM>.

Referring to <FIG>, a first method of delivering material to the target site <NUM> is shown. The first method comprises the step of the operator moving the distal end tip <NUM> within the virtual boundary <NUM>. The controller <NUM> calculates the volume of space defined by the virtual boundary <NUM> to be filled with the material, or the volume of material to be delivered to the target site <NUM> is predefined in some other manner prior to the procedure, such as preoperatively or intraoperatively by a surgeon.

The operator freely moves the distal end tip <NUM> within the virtual boundary <NUM> while the material is delivered within the virtual boundary <NUM>. To prevent overfilling, the controller <NUM> stops the delivery device <NUM> delivering the material to the target site <NUM> when the volume of the material that has been delivered to the target site <NUM> is equal to the calculated or predefined volume.

The flow rate of material being delivered from the opening <NUM> at the distal end tip <NUM> may also be controlled by the controller <NUM> (by controlling the material supply device <NUM> or valve) so that the flow rate is constant, variable, or combinations thereof. The flow rate may also be dependent on the speed with which the operator moves the distal end tip <NUM> relative to the target site <NUM>, For instance, as the speed increases the flow rate may increase, or as the speed decreases, the flow rate may decrease.

The flow rate may also be controlled by the controller <NUM> so that the flow rate is constant with respect to movement. In other words, as the operator moves the distal end tip <NUM> in the virtual boundary <NUM>, the controller <NUM> measures the speed of the distal end tip <NUM> and controls the flow rate higher or lower as the speed increases or decreases to accomplish a constant flow rate per unit of movement.

The controller <NUM> may also be programmed to slow the flow rate of material (by controlling the material supply device <NUM> or valve) the closer the operator moves the distal end tip <NUM> to the virtual boundary <NUM> with the controller <NUM> stopping the flow of the material should the distal end tip <NUM> be moved beyond the virtual boundary <NUM>. It should be understood that since the navigation system <NUM> is also tracking movement of the patient, and thus the virtual boundary <NUM>, the distal end tip <NUM> may move closer to the virtual boundary <NUM> by virtue of either the operator expressly moving the distal end tip <NUM> closer to the virtual boundary <NUM> or by virtue of patient movement, i.e., the virtual boundary <NUM> expressly moving closer to the distal end tip <NUM>.

The navigation system <NUM> and encoders of the instalment <NUM> track movement of the opening <NUM> using the methods described in <CIT>, entitled, "SURGICAL INSTRUMENT INCLUDING HOUSING, A CUTTING ACCESSORY THAT EXTENDS FROM THE HOUSING AND ACTUATORS THAT ESTABLISH THE POSITION OF THE CUTTING ACCESSORY RELATIVE TO THE HOUSING". As the opening <NUM> moves in the virtual boundary <NUM>, the controller <NUM> is able to determine the position and orientation of the opening <NUM> with respect to the virtual boundary <NUM>. The virtual boundary <NUM> may be determined to be breached by the delivery device <NUM> should any portion of a perimeter of the delivery device <NUM> defining the opening <NUM>, cross the virtual boundary <NUM>. Alternatively, the location of a center point of the opening <NUM> with respect to the tracker <NUM> is known with the controller <NUM> tracking movement of the center point with respect to the virtual boundary <NUM>. In this case, the virtual boundary <NUM><NUM> may be defined slightly smaller to account for a radius of the opening <NUM>.

The controller <NUM> may be programmed to control one or more of the actuators <NUM>, <NUM>, <NUM> via the actuator controllers <NUM> to move the distal end tip <NUM> in one or more degrees of freedom to maintain the distal end tip <NUM> within the virtual boundary <NUM> should the operator move the delivery instrument <NUM> in a way that would otherwise move the distal end tip <NUM> beyond the virtual boundary <NUM>.

Referring to <FIG>, a second method of delivering material to the target site <NUM> is shown. The second method comprises the step of the operator moving the distal end tip <NUM> within the virtual boundary <NUM>. The controller <NUM> calculates the volume of space defined by the virtual boundary <NUM> to be filled with the material, or the volume of material to be delivered to the target site <NUM> is predefined in some other manner prior to the procedure, such as preoperatively or intraoperatively by a surgeon.

Once the total volume of material to be delivered is determined, the controller <NUM>, according to one embodiment, segments the space defined by the virtual boundary <NUM> into a plurality of target subvolumes <NUM>. The total volume of material to be delivered is also separated into a plurality of material subvolumes with each of the material subvolumes assigned to one of the target subvolumes <NUM>. In some cases, the volume of material defined by a material subvolume is equal to the volume of a target subvolume <NUM> so that the target subvolume <NUM> is completely filled when the assigned material subvolume is placed within the target subvolume <NUM>. In other embodiments, the volume of material defined by a material subvolume may be less than the volume of a target subvolume <NUM> so that the target subvolume <NUM> is less than completely filled.

The operator freely moves the distal end tip <NUM> within the virtual boundary <NUM> while the material is delivered to the target site <NUM>. The target subvolume <NUM> in which the distal end tip <NUM> is currently positioned is called a current target subvolume <NUM>. To promote desired filling at the target site <NUM>, the controller <NUM> stops the delivery device <NUM> delivering the material to the target site <NUM> when the volume of material that has been delivered while the distal end tip <NUM> is in the current target subvolume <NUM> is equal to the material subvolume assigned to the current target subvolume <NUM>. Thus, as the distal end tip <NUM> is moved within the virtual boundary <NUM>, the controller <NUM> allows the delivery device <NUM> to deliver the material until each target subvolume <NUM> has been filled with the desired material subvolume until the total volume of the material has been delivered to the target site.

In this embodiment, when the operator moves the distal end tip <NUM> between different target subvolumes <NUM>, the controller <NUM> keeps a running total of the volume of material delivered to each target subvolume <NUM> so that the operator may move between the target subvolumes <NUM> before any of the target subvolumes <NUM> have completely received the desired material subvolume assigned to them. This running total is based on the flow rates at which the material supply device <NUM> supplies the material to each of the target subvolumes <NUM> and the time for which the material is delivered to the target subvolumes <NUM> at each flow rate. Volume = flow rate * time.

In this embodiment, the controller <NUM> may also be programmed to slow the flow rate of material (by controlling the material supply device <NUM> or valve) the closer the distal end tip <NUM> moves to the virtual boundary <NUM> with the controller <NUM> stopping the flow of the material should the distal end tip <NUM> move beyond the virtual boundary <NUM>.

Alternatively, the controller <NUM> may be programmed to control one or more of the actuators <NUM>, <NUM>, <NUM> via the actuator controllers <NUM> to move the distal end tip <NUM> in one or more degrees of freedom to maintain the distal end tip <NUM> within the virtual boundary <NUM> should the operator move the delivery instrument <NUM> in a way that would otherwise move the distal end tip <NUM> beyond the virtual boundary <NUM>.

Referring to <FIG>, a third method of delivering material to the target site <NUM> is shown. In this third method, the controller <NUM> determines a path <NUM> within the virtual boundary <NUM> along which the distal end tip <NUM> is to deliver the material. The path may be defined by a series of coordinates in the camera coordinate system. The operator places the distal end tip <NUM> generally in a gross location within the virtual boundary <NUM>.

Once the distal end tip <NUM> is grossly located, the controller <NUM> actuates one or more of the actuators <NUM>, <NUM>, <NUM> via the actuator controllers <NUM> to move the distal end tip <NUM> autonomously along the path <NUM> while the operator manually maintains the gross location. The controller <NUM> controls the flow rate at which the material is delivered to the target site <NUM> as the distal end tip <NUM> follows the path <NUM>.

Control of the flow rate may include, for example, controlling the flow rate to be constant along the path <NUM>, or variable along the path <NUM>. Alternatively, different segments of the path <NUM> may be assigned different predefined flow rates. In this case, the controller <NUM> controls the material supply device <NUM> to convey the material at the different, predefined flow rates based on the segment at which the distal end tip <NUM> is located.

Referring to <FIG>, an alternative embodiment of the delivery system is shown generally at <NUM>'. In this embodiment, a delivery instrument <NUM>' is attached to a robotic manipulator <NUM>. The delivery system <NUM>' still includes the delivery device <NUM> removably attached to the delivery instrument <NUM>', a plurality of actuators <NUM>', <NUM>', <NUM>' (joint motors), the navigation system <NUM>, the controller <NUM>, and the material supply system <NUM>.

The robotic manipulator <NUM> comprises a plurality of linkages <NUM> forming an arm, and a plurality of active joints (not numbered) for moving the delivery device <NUM> with respect to the target site <NUM>. The robotic manipulator <NUM> is operatively coupled to the delivery device <NUM>, a sensor <NUM>, such as a force/torque sensor may be coupled between the delivery instrument <NUM>' and the arm of the robotic manipulator <NUM> for sensing forces and/or torques applied to the delivery instrument <NUM>' by the operator.

The robotic manipulator <NUM> may operate in multiple modes including a manual mode and a semi-autonomous mode. An example of a robotic manipulator <NUM> that can operate in multiple modes is described in <CIT>, entitled, "Surgical Manipulator Capable of Controlling a Surgical Instalment in Multiple Modes". Any of the manual and semi-autonomous control techniques described in <CIT> with respect to manipulating the anatomy using the surgical instrument described therein may be applied fully to dispensing the material on the anatomy using the delivery instrument <NUM> as described herein.

In the manual mode, the operator grasps a grasping portion <NUM>' of the delivery instrument <NUM>' to deliver the material to the target site <NUM>. The sensor <NUM> senses the forces/torques applied to the grasping portion <NUM>' and the controller <NUM> receives signals representative of the sensed forces/torques. The controller <NUM> is configured to control movement of the delivery instrument <NUM>' and/or the distal end tip <NUM> via the robotic manipulator <NUM> in response to the operator's manually applied movements. That is, the actuators <NUM>', <NUM>', <NUM>' are actively driven to move the delivery instrument <NUM>' and/or the distal end tip <NUM> to the desired position as sensed by the sensor <NUM> pursuant to the operator's manually applied forces/torques to the grasping portion <NUM>'. The navigation system <NUM> tracks the delivery device <NUM> to keep the distal end tip <NUM> in a desired relationship to the virtual boundary <NUM>. In the manual mode, the operator is able to deliver the material to the target site <NUM> using the delivery methods described above with respect to <FIG>.

As described above, the robotic manipulator <NUM>, and more specifically, the delivery instrument <NUM>' attached to the robotic manipulator <NUM> may be equipped with the button or trigger <NUM>. In the manual mode, pressing the trigger <NUM> allows manual control over the dispensing of the material according to any suitable control, such as those described above.

In the semi-autonomous mode, the robotic manipulator <NUM> delivers the material autonomously to the target site <NUM><NUM> based on predefined parameters. In the semi-autonomous mode, the controller <NUM> is configured to autonomously control movement of the delivery instrument <NUM>' and/or the distal end tip <NUM> via the robotic manipulator <NUM>. The predefined parameters may be, for example, a preprogrammed delivery path or pattern. In one example, the robotic manipulator <NUM> operates in the semi-autonomous mode with essentially no directional input from the operator.

In order for the robotic manipulator <NUM> to autonomously displace the delivery device <NUM>, the operator may actuate a command by continually depressing a control button or switch associated with the robot. Upon the negation of the command by the operator, the advancement of the delivery instrument <NUM>' by the robotic manipulator <NUM> at least temporarily stops. The control button or switch to start autonomous movement of the robotic manipulator <NUM> may be the trigger <NUM> or foot pedal as described above.

Additionally or alternatively, when the delivery instrument <NUM>' attached to the robotic manipulator <NUM> is equipped with the button or trigger <NUM>, pressing the trigger <NUM> in the semi-autonomous mode may allow manual control over the autonomous dispending of the material according to any suitable control, such as those described above. For example, material may be autonomously dispensed via the robotic manipulator <NUM> in this mode by pressing the trigger <NUM> once. Thereafter, the trigger <NUM> may be pressed again to stop autonomous dispensing of the material via the robotic manipulator <NUM>. Alternatively, material may be autonomously dispensed via the robotic manipulator <NUM> in this mode by holding down the trigger <NUM>.

In some embodiments, the delivery instrument <NUM>' provides haptic feedback to the operator when the controller <NUM> determines the operator is attempting to make an undesired movement. One example of an undesired movement includes movement that attempts to move the delivery instrument <NUM>', or distal end tip <NUM> past the virtual boundary <NUM>. The haptic feedback generally includes any type of feedback alerting the operator's sense of touch. The haptic feedback may include any one or more of force feedback, vibrational feedback, physical repulsion and the like. For example, the delivery instrument <NUM>' may generate vibration energy in the grasping portion <NUM>' or the plurality of actuators <NUM>', <NUM>', <NUM>' may transmit force back to the operator through the grasping portion <NUM>' that is sensed by the operator to alert the operator to keep the distal end tip <NUM> in a desired location. In some instances, the distal end tip <NUM> is actuated to move away from the virtual boundary <NUM> as the distal end tip <NUM> attempts to exceed limits of the virtual boundary <NUM>. This repulsive movement may be accompanied by haptics to alert the operator of the virtual boundary <NUM> limits and/or to alert the operator that such repulsion has occurred.

Referring to <FIG>, a second alternative embodiment of the delivery system is shown generally at <NUM>". In this embodiment, the delivery system <NUM>" includes a delivery instrument <NUM>", the delivery device <NUM>, a navigation system <NUM>", the controller <NUM>", and the material supply system <NUM> for delivering material to the delivery device <NUM>. Like the prior embodiments, the navigation system <NUM> tracks the delivery device <NUM> to keep the distal end tip <NUM> of the delivery device <NUM> in a desired relationship to the virtual boundary <NUM>.

In this embodiment, the operator is a human operator that manually supports and moves the delivery instrument <NUM>" directly without any actuators to cause movement of the delivery device <NUM>. The delivery instrument <NUM>" includes the grasping portion <NUM>" for being grasped by the operator. The grasping portion <NUM>" is fixed to the delivery device <NUM> (and the opening therein) by press fit, adhesive, bayonet connection, threaded connection, or the like. The delivery device <NUM> may also be integral with the delivery instrument <NUM>" such that the delivery device <NUM> is a portion of the delivery instrument <NUM>" and the grasping portion is another portion of the delivery instrument <NUM>".

In this embodiment, navigation system <NUM>" includes the same features as the other embodiments except that the controller <NUM>" integrates and combines the functionality of the navigation computer <NUM> and the controller <NUM>. The controller <NUM>" in this embodiment controls the material supply system <NUM> using the delivery methods described above with respect to <FIG>. The flow rate may also be controlled in accordance with the examples described above.

In certain embodiments, it may be desired to track the material being delivered from the delivery device <NUM>. For example, the material may ultimately form an implant and a surgeon may wish to visualize construction of the implant during the procedure. Accordingly, the material being delivered may be continuously shown on the display to show the surgeon the progress being made. This may involve tracking the target site, the opening <NUM> and the flow rate of material and generating corresponding output signals to the display to show a representation of the material that takes into account the position and orientation of the opening <NUM> during delivery and the amount of material being delivered. The material being delivered may also be color coded with the latest delivered material being represented on the display as one color and older material previously dispensed beforehand being represented on the display by a different color. The target site, such as a bone, is displayed to show the construction of the implant with respect to the target site so that the surgeon can visualize the construction of the implant with respect to the actual anatomy of the patient.

Claim 1:
A delivery system (<NUM>') for delivering a material to a target site (<NUM>), said delivery system (<NUM>') comprising:
a robotic manipulator (<NUM>) comprising a plurality of links (<NUM>) forming an arm and one or more joint motors (<NUM>', <NUM>', <NUM>') coupled to said plurality of links (<NUM>), wherein a delivery instrument (<NUM>') is attached to the robotic manipulator (<NUM>);
a delivery device (<NUM>) having an opening (<NUM>) and being configured to deliver the material to the target site (<NUM>) through the opening (<NUM>), the delivery device (<NUM>) removably attached to the delivery instrument (<NUM>');
a navigation system (<NUM>) being configured to track the delivery device (<NUM>) and the target site (<NUM>) and to generate position signals; and
a controller (<NUM>') in communication with said delivery device (<NUM>) and said navigation system (<NUM>) and being configured to:
define a virtual boundary (<NUM>) associated with the target site (<NUM>), wherein the virtual boundary (<NUM>) is utilized to constrain movement of the delivery device (<NUM>);
control movement of said opening (<NUM>) with respect to the virtual boundary (<NUM>) based on the position signals from the navigation system (<NUM>), by controlling said one or more joint motors (<NUM>', <NUM>', <NUM>') to move said opening (<NUM>) via one or more of said links (<NUM>);
characterized in that
the controller (<NUM>') is further configured to actuate a distal end tip (<NUM>) of the delivery device (<NUM>) to move away from the virtual boundary (<NUM>) in response to detecting an attempt to move the delivery instrument (<NUM>') or distal end tip (<NUM>) beyond the virtual boundary (<NUM>).