Tissue sensing with an ultrasonic resection tool

Abstract

A surgical system includes an ultrasonic instrument operable in a tissue sense mode and a tissue resection mode. In the tissue resection mode, a first AC drive signal is sourced to the ultrasonic instrument that induces vibrations in a tip of the instrument for resecting patient tissue, and in the tissue sense mode, a second AC drive signal is sourced to the ultrasonic instrument that induces vibrations in the tip that are insufficient for resecting the patient tissue. A frequency corresponding to a target vibratoiy characteristic of the ultrasonic instrument is determined based on a voltage measurement and a current measurement of the second AC drive signal, and is used to determine a type of patient tissue being contacted by the distal region of the tip. Operation of the surgical system is then controlled based on the determined tissue type.

Description

TISSUE SENSING WITH AN ULTRASONIC RESECTION TOOLCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and all the benefits of U.S. Provisional Application Nos. 63 / 589,630, filed October 11, 2023, and 63 / 589,988, filed October 12, 2023, the disclosures of which are hereby incorporated by reference herein in their entirety.BACKGROUND

[0002] Ultrasonic surgical aspirators operate to resect patient tissue by rapidly vibrating against the tissue and simultaneously applying suction through a built-in pathway. Limiting resection of non-targeted tissue when using such devices conventionally depends on the operator’s ability to distinguish between different tissue types and react accordingly, which can be especially difficult when the view of the surgical site is obstructed.SUMMARY

[0003] A system of one or more computers can be configured to perform particular operations or actions by virtue of having software, firmware, hardware, or a combination of them installed on the system that in operation causes or cause the system to perform the actions. One or more computer programs can be configured to perform particular operations or actions by virtue of including instructions that, when executed by data processing apparatus, cause the apparatus to perform the actions.

[0004] One general aspect includes a surgical system for detecting tissue types using an ultrasonic instrument for resecting patient tissue. The surgical system includes a power supply configured to source varying AC drive signals to the ultrasonic instrument to induce varying vibrations in a tip of the ultrasonic instrument. The system includes at least one sensor for measuring at least one electrical characteristic of the AC drive signals. The system includes one or more controllers coupled to the at least one sensor and the power supply and configured to: operate the ultrasonic instrument in a tissue resection mode in which a first AC drive signal is sourced to the ultrasonic instrument that induces vibrations in the tip of the ultrasonic instrument for resecting patient tissue; operate the ultrasonic instrument in a tissue sense mode in which a second AC drive signal is sourced to theultrasonic instrument that induces vibrations in the tip for sensing patient tissue, the second AC drive signal being lower power than the first AC drive signal; obtain at least one measured first electrical characteristic of the second AC drive signal; determine a first frequency corresponding to a target vibratory characteristic of the ultrasonic instrument based on the at least one measured first electrical characteristic; determine a type of patient tissue being contacted by a distal region of the tip based on the determined first frequency; and control operation of the surgical system based on the determined type of patient tissue. Other implementations related to this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the configured actions of the one or more controllers, and methods for detecting tissue types using an ultrasonic instrument for resecting patient tissue each comprising performance of the above actions.

[0005] One general aspect includes a surgical system for detecting tissue types using an ultrasonic instrument for resecting patient tissue. The surgical system includes a power supply configured to source varying AC drive signals to the ultrasonic instrument to induce varying vibrations in a tip of the ultrasonic instrument. The system includes at least one sensor for measuring at least one electrical characteristic of the AC drive signals. The system includes one or more controllers coupled to the at least one sensor and the power supply and configured to: source an AC drive signal to the ultrasonic instrument that induces vibrations in a tip of the ultrasonic instrument for resecting patient tissue; obtain at least one measured first electrical characteristic of the AC drive signal; determine one or more frequency characteristics of the AC drive signal based on the at least one measured first electrical characteristic, each of the frequency characteristics corresponding to a frequency other than a fundamental frequency of the AC drive signal; determine a type of patient tissue being contacted by a distal region of the tip based on the determined one or more frequency characteristics; and control operation of the surgical system based on the determined type of patient tissue. Other implementations related to this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the configured actions of the one or more controllers, and methods for detecting tissue types using an ultrasonic instrument for resecting patient tissue each comprising performance of the above actions.

[0006] One general aspect includes a surgical system for detecting tissue types using an ultrasonic instrument for resecting patient tissue. The surgical system includes a power supply configured to source varying AC drive signals to the ultrasonic instrument to induce varying vibrations in a tip of the ultrasonic instrument. The system includes at least one sensor for measuring at least one electrical characteristic of the AC drive signals. The system includes one or more controllers coupled to the at least one sensor and the power supply and configured to: source an AC drive signal to the ultrasonic instrument that induces vibrations in the tip that are insufficient for resecting the patient tissue; determine a first frequency corresponding to a target vibratory characteristic of the ultrasonic instrument when in an unloaded state; obtain at least one measured first electrical characteristic of the AC drive signal; determine a second frequency corresponding to the target vibratory characteristic of the ultrasonic instrument when in a loaded state; determine a type of patient tissue being contacted by a distal region of the tip based on the first frequency and the second frequency; and control operation of the surgical system based on the determined type of patient tissue. Other implementations related to this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the configured actions of the one or more controllers, and methods for detecting tissue types using an ultrasonic instrument for resecting patient tissue each comprising performance of the actions described above.

[0007] One general aspect includes a surgical system for detecting tissue types using an ultrasonic instrument for resecting patient tissue. The surgical system includes a power supply configured to source varying AC drive signals to the ultrasonic instrument to induce varying vibrations in a tip of the ultrasonic instrument. The system includes at least one sensor for measuring at least one electrical characteristic of the AC drive signals. The system includes one or more controllers coupled to the at least one sensor and the power supply and configured to: operate the ultrasonic instrument in a tissue resection mode in which a first AC drive signal is sourced to the ultrasonic instrument that induces vibrations in the tip of the ultrasonic instrument for resecting patient tissue, where the first AC drive signal includes a frequency component corresponding to a first resonant mode of the tip; operate the ultrasonic instrument in a tissue sense mode in which a second AC drive signalis sourced to the ultrasonic instrument that induces vibrations in the tip that are insufficient for resecting the patient tissue, where the second AC drive signal includes a frequency component corresponding to a second resonant mode of the tip; obtain at least one measured first electrical characteristic of the second AC drive signal; determine a type of patient tissue being contacted by a distal region of the tip based on the at least one measured first electrical characteristic; and control operation of the surgical system based on the determined type of patient tissue. Other implementations related to this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the configured actions of the one or more controllers, and methods for detecting tissue types using an ultrasonic instrument for resecting patient tissue each comprising performance of the actions described above.

[0008] One general aspect includes a surgical system for detecting tissue types using an ultrasonic instrument for resecting patient tissue. The surgical system includes a power supply configured to source varying AC drive signals to the ultrasonic instrument to induce varying vibrations in a tip of the ultrasonic instrument. The system includes at least one sensor for measuring at least one electrical characteristic of the AC drive signals. The system includes one or more controllers coupled to the at least one sensor and the power supply and configured to: operate the ultrasonic instrument in a tissue resection mode in which a first AC drive signal is sourced to the ultrasonic instrument that induces vibrations in the tip of the ultrasonic instrument for resecting patient tissue, the first AC drive signal being limited to a first allowed frequency range associated with the tissue resection mode; operate the ultrasonic instrument in a tissue sense mode in which a second AC drive signal is sourced to the ultrasonic instrument that induces vibrations in the tip for sensing patient tissue, the second AC drive signal being limited to a second allowed frequency range associated with the tissue sensing mode; obtain at least one measured first electrical characteristic of the second AC drive signal; determine a type of patient tissue being contacted by a distal region of the tip based on the at least one measured first electrical characteristic; and control operation of the surgical system based on the determined type of patient tissue. Other implementations related to this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computerstorage devices, each configured to perform the configured actions of the one or more controllers, and methods for detecting tissue types using an ultrasonic instrument for resecting patient tissue each comprising performance of the actions described above.

[0009] One general aspect includes a surgical system for detecting tissue types using an ultrasonic instrument for resecting patient tissue. The surgical system includes a power supply configured to source varying AC drive signals to the ultrasonic instrument to induce varying vibrations in a tip of the ultrasonic instrument. The system includes at least one sensor for measuring at least one electrical characteristic of the AC drive signals. The system includes one or more controllers coupled to the at least one sensor and the power supply and configured to: operate the ultrasonic instrument in a tissue resection mode in which a first AC drive signal is sourced to the ultrasonic instrument that induces vibrations in a tip of the ultrasonic instrument for resecting patient tissue and in which suction is provided at a distal region of the tip through at least a portion of the ultrasonic instrument; operate the ultrasonic instrument in a tissue sense mode in which a second AC drive signal is sourced to the ultrasonic instrument that induces vibrations in the tip for sensing patient tissue that are insufficient for resecting patient tissue and in which the suction provided at the distal region of the tip through the at least a portion of the ultrasonic instrument is disabled; obtain at least one measured first electrical characteristic of the second AC drive signal; determine a type of patient tissue being contacted by the distal region of the tip based on the at least one measured first electrical characteristic; and control operation of the surgical system based on the determined type of patient tissue. Other implementations related to this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the configured actions of the one or more controllers, and methods for detecting tissue types using an ultrasonic instrument for resecting patient tissue each comprising performance of the actions described above.

[0010] One general aspect includes a surgical system for detecting tissue types using an ultrasonic instrument for resecting patient tissue. The surgical system includes a power supply configured to source varying AC drive signals to the ultrasonic instrument to induce varying vibrations in a tip of the ultrasonic instrument. The system includes at least one sensor for measuring at least one electrical characteristic of the AC drive signals. Thesystem includes one or more controllers coupled to the at least one sensor and the power supply and configured to: operate the ultrasonic instrument in a tissue resection mode in which an AC drive signal is sourced to the ultrasonic instrument that induces vibrations in a tip of the ultrasonic instrument for resecting patient tissue and in which suction is provided at a distal region of the tip through at least a portion of the ultrasonic instrument; obtain at least one measured first electrical characteristic of the AC drive signal; determine a type of patient tissue being contacted by the distal region of the tip based on the at least one measured first electrical characteristic; and regulate the suction provided at the distal region of the tip when operating in the tissue resection mode based on the determined type of patient tissue. Other implementations related to this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the configured actions of the one or more controllers, and methods for detecting tissue types using an ultrasonic instrument for resecting patient tissue each comprising performance of the above described above.

[0011] One general aspect includes a sleeve for an ultrasonic surgical tool including a tip and at least one driver to which the tip is coupled and to which an AC drive signal is sourced from a control console to vibrate the tip. The sleeve includes a body including open proximal and distal ends and a conduit for flowing irrigating fluid down the sleeve and out the open distal end during operation of the ultrasonic surgical tool to vibrate the tip, the body adapted to be disposed around the tip and placed in an operative position for operating the ultrasonic surgical tool to vibrate the tip in which the tip extends from the open proximal end and out the open distal end. The sleeve includes a tip memory disposed in the body and storing data for controlling actuation of the tip in the tissue resection mode and in the tissue sense mode, where the data for controlling actuation of the tip indicates at least one of a drive signal frequency for the tissue sense mode, a drive signal frequency for the tissue resection mode that differs from the drive signal frequency for the tissue sense mode, an allowed drive signal frequency range for the tissue sense mode, an allowed drive signal frequency range for the tissue resection mode that differs from the allowed drive signal frequency range of the tissue sense mode, a drive signal frequency corresponding to a target vibratory characteristic of the ultrasonic surgical tool when in an unloaded state, data foridentifying varying tissue types in contact with a distal region of the tip as a function of drive signal electrical characteristics, and suction parameters for varying tissue types.

[0012] One general aspect includes a method of detecting tissue types using a surgical system including an ultrasonic instrument for resecting patient tissue. The method includes operating the ultrasonic instrument in a tissue resection mode in which a first AC drive signal is sourced to the ultrasonic instrument that induces vibrations in a tip of the ultrasonic instrument for resecting patient tissue, and providing suction at a distal region of the tip through at least a portion of the ultrasonic instrument when operating in the tissue resection mode. The method includes operating the ultrasonic instrument in a tissue sense mode in which a second AC drive signal is sourced to the ultrasonic instrument that induces vibrations in the tip that are insufficient for resecting the patient tissue. The method includes obtaining a voltage measurement and a current measurement of the second AC drive signal when the distal region of the tip is in contact with the patient tissue, determining a frequency corresponding to a target vibratory characteristic of the ultrasonic instrument based on the voltage measurement and the current measurement, determining a type of patient tissue being contacted by the distal region of the tip based on the determined frequency, and controlling operation of the surgical system based on the determined type of patient issue.

[0013] One general aspects includes a method of detecting tissue types using a surgical system including an ultrasonic instrument for resecting patient tissue. The method includes sourcing an AC drive signal to the ultrasonic instrument that induces vibrations in a tip of the ultrasonic instrument for resecting patient tissue, and providing suction at a distal region of the tip through at least a portion of the ultrasonic instrument when the tip is vibrating to resect the patient tissue. The method includes obtaining a current measurement of the AC drive signal, and determining one or more frequency characteristics of the AC drive signal based on the current measurement of the AC drive signal, each of the frequency characteristics corresponding to a frequency other than a fundamental frequency of the AC drive signal, and determining a type of the patient issue being contacted by the distal region of the tip based on the one or more frequency characteristics. The method includes controlling operation of the surgical system based on the determined type of the patient issue.

[0014] Other aspects include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of any of the above methods.

[0015] Implementations of any of the aspects may include a robotic manipulator coupled to the ultrasonic instrument and configured to guide the ultrasonic instrument to treat the patient tissue, and may include controlling the robotic manipulator based on the determined type of patient tissue, such as by adjusting a parameter of a virtual object (e.g., haptic object) associated with the patient tissue and used to control the robotic manipulator.BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG. 1 illustrates a surgical system including an ultrasonic resection system with an ultrasonic instrument for resecting and sensing patient tissue, a surgical navigation system for tracking a position of the ultrasonic instrument, and a robotic manipulator for maneuvering and / or guiding movement of the ultrasonic instrument relative to the patient tissue according to an exemplary aspect.

[0017] FIG. 2 illustrates the ultrasonic resection system in additional detail according to an exemplary aspect.

[0018] FIG. 3 illustrates the ultrasonic instrument in additional detail according to an exemplary aspect.

[0019] FIGS. 4A and 4B illustrate current flow through the ultrasonic instrument according to an exemplary aspect.

[0020] FIG. 5 illustrates components that may be incorporated into a console of the ultrasonic resection system according to an exemplary aspect.

[0021] FIG. 6 illustrates components that may be incorporated into the ultrasonic instrument according to an exemplary aspect.

[0022] FIG. 7 illustrates a process for low power tissue sensing using the ultrasonic instrument that may be implemented by the surgical system according to an exemplary aspect.

[0023] FIG. 8 illustrates a process for high power tissue sensing using the ultrasonic instrument that may be implemented by the surgical system according to an exemplary aspect.DETAILED DESCRIPTION

[0024] Systems and methods for identifying different patient tissues using an ultrasonic instrument that is operatable to also resect patient tissue are described herein. The ultrasonic instrument may include a tip configured to vibrate upon application of an AC drive signal to the instrument. The vibrating tip may then be placed against tissue, which may cause the instrument to exhibit varying operating characteristics depending on the mechanical properties of the contacted tissue. This variance in operating characteristics may be utilized to distinguish between contact with different types of patient tissue, such as har’d tissue (e.g., bone) versus soft tissue (e.g., dura). In some implementations, this information may be utilized to determine whether to operate the ultrasonic instrument in a resection mode in which contacted tissue is fragmented using the ultrasonic instrument, and / or to determine the power level in which to operate the ultrasonic instrument to fragment the tissue.

[0025] In some implementations, the ultrasonic instrument may be operable in multiple modes, namely a tissue resection mode and a tissue sense mode. In the tissue sense mode, relatively low amplitude vibrations, in some cases pulsed amplitude vibrations, may be induced in the tip of the ultrasonic instrument. These vibrations may be insufficient to resect patient tissue in and around a target site, and instead function to merely probe tissue contacted by the tip. Different tissues may have varying impacts on the vibratory characteristics of the ultrasonic instrument, such as by causing varying changes to the resonant frequency of the ultrasonic instrument. Accordingly, varying jumps or changes in the resonant frequency of the ultrasonic instrument may be correlated to contact of the vibrating tip with different types of tissue.

[0026] In some implementations, when the tip is contacted with a tissue type desired to be resected, operation of the ultrasonic instrument may be switched from the tissue sense mode to the tissue resection mode. In the tissue resection mode, relatively high amplitudevibrations may be induced in the tip of the ultrasonic instrument, such as based on a user requested power level, for resecting the contacted patient tissue. The tissue resection mode may similarly include a sensing function for determining a type of tissue being contacted by the tip of the ultrasonic instrument as the tip is operated to fragment tissue. For instance, the level of vibrations of the ultrasonic instrument that are not at the main drive frequency may be monitored and correlated to varying tissue types. In some implementations, when the tissue type determined during operation of the ultrasonic instrument in the tissue resection mode indicates contact with tissue desired to remain intact or adjacent tissue to remain intact, operation of the ultrasonic instrument may be adjusted so as to limit potential resection of the non-targeted tissue. For instance, operation of the ultrasonic instrument may be switched back to the tissue mode, or may be adjusted so as to maintain operation in the tissue resection mode but at a reduced power level.

[0027] The ability to leverage an ultrasonic instrument operative to resect patient tissue to also sense the type of tissue being contacted by the instrument offers several benefits. In addition to optimizing the removal of targeted tissue while preserving non-targeted tissue (e.g., during an end plate preparation procedure to remove soft tissue while sparing the harder bone tissue), implementations described herein may enable continued sensing of the tissue type while fragmenting the tissue (e.g., instead of stopping fragmentation to probe for the tissue type), and also enable sensing tissue using the same instrument as used for resection (e.g., instead of prolonging a procedure by switching between a fragmentation instrument and a probing instrument), thus improving procedure speed. As a further example, implementations described herein may be utilized to provide breakthrough and / or pre-breakthrough detection, which may be used to cease or reduce power to the ultrasonic instrument so as to reduce potential damage to sensitive structures and other non-targeted tissues adjacent patient tissue targeted for resection. For instance, when cutting bone towards the spinal cord, the vibrations of the tip may be turned off as soon as breakthrough of the bone is detected. As a further instance, when thinning the skull base near the carotid artery, the vibrations of the tip may be turned off before break through, such as to maintain a thin layer of bone as desired.

[0028] Implementations described herein may also be utilized to improve or verify the accuracy of surgical navigation, such as by comparing the types of tissue indicated by autosegmentation of preoperative scans and / or navigation tracking to what the ultrasonic instrument is sensing, and taking corresponding action, such as described in PCT Application No. PCT / US2023 / 017790, filed April 6, 2023, the contents of which are hereby incorproated by reference herein in their entirety. In robotic applications, implementations described herein may also be used to adjust parameters of virtual and / or haptic objects used to control a robotic manipulator coupled to the ultrasonic instrument, such as those haptic objects described in US Patent Nos. 9,775,681 and 10,398,449, the contents of each which are hereby incorporated herein by reference in their entirety. As a further example, the tissue types detected according to the implementations described herein may be used with navigation or robotic kinematics to generate virtual objects corresponding to patient anatomy in a known coordinate system, and / or to adjust the pose and / or shape of such virtual objects in the known coordinate system, such as to account for tissue movement during the procedure.

[0029] Turning now to the Figures, FIG. 1 illustrates a surgical system 10 for treating an anatomy (i.e., target site) of a patient P. The surgical system 10 may be located in a surgical setting such as an operating room of a medical facility. The surgical system 10 may include an ultrasonic resection system 11, a surgical navigation system 12, and a robotic manipulator 14.

[0030] The robotic manipulator 14 may be coupled to an ultrasonic instrument 15 of the ultrasonic resection system 11, and may be configured to maneuver and / or guide the ultrasonic instrument 15 to treat a target volume of patient tissue, such as at the direction of a surgeon and / or the surgical navigation system 12. For example, the surgical navigation system 12 may cause the robotic manipulator 14 to maneuver the ultrasonic instrument 15 to resect a target volume of patient tissue while avoiding other objects adjacent the target volume in the surgical workspace, such as other medical tools and adjacent anatomical structures desired to be avoided. Additionally or alternatively, the surgeon may manually hold and maneuver the ultrasonic instrument 15 while receiving guidance from the surgical navigation system 12 and / or from the robotic manipulator 14. For instance, the robotic manipulator 14 may be configured to provide haptic feedback and / or to constrain movement of the ultrasonic instrument 15 as the ultrasonic instrument 15 is moved by the surgeon relative to the target volume to avoid adjacent objects.

[0031] The surgical navigation system 12 may be configured to track a pose (i.e., location and orientation) of objects of interest within the surgical workspace using tracker-based localization. The tracked objects may include, but are not limited to, anatomical structures of the patient and surgical instruments such as the ultrasonic instrument 15. The tracked anatomical structures of the patient may include soft and hard tissues such as fat, ligaments, muscle, skin, and bone. The tracked surgical instruments may include, in addition to the ultrasonic instrument 15, retractors, other cutting tools, inserters, implants, and waste management devices used during the surgical procedure.

[0032] Each object of interest may be coupled to a tracker 16 for localizing the object in a known coordinate system. For instance, in the example illustrated in FIG. 1, the surgical system 10 is being used to perform a spinal procedure on a patient P, such as a minimally invasive interbody fusion in which an intervertebral disc space is being prepared using the ultrasonic instrument 15 to receive an implant (e.g., spacer, graft, cage). To support an optimal preparation of the intervertebral disc space with the ultrasonic instrument 15, the surgical navigation system 12 may be configured to continuously track the pose of multiple vertebra V using a patient tracker 16A coupled to each vertebra V, and to also track a pose of the ultrasonic instrument 15 via an instrument tracker 16B coupled to the ultrasonic instrument 15 or to the robotic manipulator 14 at a position with a known relationship to the ultrasonic instrument 15.

[0033] In some implementations, the trackers 16 may be optical trackers 16, in which case the surgical navigation system 12 may be configured to detect light signals emitted from each tracker 16 by imaging the tracker 16. The surgical navigation system 12 may then be configured to determine the poses of the trackers 16 in a known coordinate system based on the images, and thereafter determine the poses of the objects to which the trackers 16 are affixed in the known coordinate system based on the determined poses of the trackers 16 and predefined positional relationships between the objects and trackers 16. The surgical navigation system 12 may have various functions and features such as described in U.S. Patent No. 7,725,162 and U.S. Patent Publication No. 2020 / 0100849, the contents of each which are hereby incorporated by reference herein in their entirety. While examples are provided in which the surgical navigation system 12 is an optical tracking system, other tracking systems may be employed.

[0034] For instance, in some implementations, the surgical navigation system 12 may be realized as an electromagnetic tracking system, with each tracker 16 including a position sensor located at and / or embedded therein. The position sensor may include a coil that, when moved within an electromagnetic field, generates electrical current in the coil, which may then be communicated to the surgical navigation system 12. This phenomenon may enable the surgical navigation system 12 to determine the location of the coil within a three- dimensional space, such as relative to a target volume of patient tissue.

[0035] By way of example only, the position sensor may be constructed and operable in accordance with at least some of the teachings of U.S. Pat. No. 8,702,626, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 8,320,711, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 8,190,389, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 8,123,722, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 7,720,521, the disclosure of which is incorporated by reference herein; U.S. Pat. Pub. No. 2014 / 0364725, the disclosure of which is incorporated by reference herein; U.S. Pat. Pub. No. 2014 / 0200444, the disclosure of which is incorporated by reference herein; U.S. Pat. Pub. No. 2012 / 0245456, the disclosure of which is incorporated by reference herein; U.S. Pat. Pub. No. 2011 / 0060214, the disclosure of which is incorporated by reference herein; U.S. Pat. Pub. No. 2008 / 0281156, the disclosure of which is incorporated by reference herein; and / or U.S. Pat. Pub. No. 2007 / 0208252, the disclosure of which is incorporated by reference herein.

[0036] Responsive to determining the poses of objects of interest, the surgical navigation system 12 may display the relative poses of the tracked objects to aid the surgeon, such as in the form of virtual models. The surgical navigation system 12 may also control operation of the robotic manipulator 14 and / or the ultrasonic instrument 15 based on virtual objects associated with the tracked objects, such as described in PCT Application No. PCT / US2022 / 054115, filed December 28, 2022, U.S. Patent No. 9,775,681, and U.S. Patent Publication No. 2022 / 0338938, the contents of each of which are hereby incorporated by reference herein in their entirety.

[0037] For example, the surgical navigation system 12 may identify a target volume of patient tissue to be treated and potential obstacles in the surgical workspace based on the tracked objects, and generate virtual objects corresponding to the tracked objects in aknown coordinate system. The surgical navigation system 12 may then control the robotic manipulator 14 to maneuver and / or guide the ultrasonic instrument 15 based on the virtual objects, such as to lead the ultrasonic instrument 15 to the patient tissue to be treated and / or away from contact with anything beyond the target volume of patient tissue to be treated. In this way, the surgical navigation system 12 may both improve surgical accuracy and eliminate damage to surgical instruments caused by unintended contact with other objects, which may result in undesired debris at the target site. Additionally or alternatively, the surgical navigation system 12 may be configured to adjust operation of the ultrasonic instrument 15 based on the virtual objects, such as by ceasing or reducing power to the ultrasonic instrument 15 when the virtual objects indicate the ultrasonic instrument 15 is contacting or near contacting tissue outside the target volume of tissue to be treated.

[0038] Still referring to FIG. 1, the surgical navigation system 12 may include a localizer camera 20 and a navigation cart assembly 22. The navigation cart assembly 22 may house a navigation controller 24 configured to implement the functions, features, and processes of the surgical navigation system 12 described herein. For instance, the navigation controller 24 may be configured to convert optical-based image data received from the localizer camera 20 into object pose data indicative of the poses of the tracked objects in the surgical workspace, and to control operation of the robotic manipulator 14 based on the indicated poses as described herein.

[0039] The navigation controller 24 may include or be in operative communication with a navigation storage 25, and / or may be in operative communication with a user interface 28 A of the surgical navigation system 12. The navigation storage 25 may store data for facilitating operation of the surgical navigation system 12, as described in more detail below. The user interface 28A may facilitate user interaction with the surgical navigation system 12 and navigation controller 24. For example, the user interface 28A may include one or more output devices that provide information to a user, such as from the navigation controller 24. The output devices may include a display 30 adapted to be situated outside of a sterile field including the surgical workspace, and may include a display 32 adapted to be situated inside the sterile field. The displays 30, 32 may be adjustably mounted to the navigation cart assembly 22. The user interface 28A may also include one or more input devices that enable user-input to the surgical navigation system 12. The input devices mayinclude a keyboard, mouse, and / or touch screen 34 that can be interacted with by a user to input surgical parameters to and control aspects of the navigation controller 24. The input devices may also include a microphone that enables user input through voice-recognition technology.

[0040] The localizer camera 20 may be configured to facilitate the identification of the poses of the tracked objects in the surgical workspace relative to a known coordinate system, such as a localizer coordinate system LCLZ of the localizer camera 20, by generating the image data indicating poses of the trackers 16 affixed to the objects. The localizer camera 20 may have an outer casing 36 that houses at least two optical sensors 38. Each of the optical sensors 38 may be adapted to detect light signals of a particular frequency band that are transmitted by the trackers, such as nonvisible light signals (e.g., infrared or ultraviolet). While FIG. 1 illustrates the localizer camera 20 as a single unit with multiple optical sensors 38, in an alternative example, the localizer camera 20 may include separate units arranged around the surgical workspace, each with a separate outer casing 36 and one or more optical sensors 38.

[0041] The optical sensors 38 may be one-dimensional or two-dimensional charge-coupled devices (CCDs). For example, the outer casing 36 may house two two-dimensional CCDs or three one-dimensional CCDs for triangulating the positions of the optical markers of the trackers 16 in the surgical workspace. Additionally or alternatively, the localizer camera 20 may employ other optical sensing technologies, such as complementary metal-oxide semiconductor (CMOS) active pixels.

[0042] The localizer camera 20 may be mounted to an adjustable arm to selectively position the optical sensors 38 with a field of view of the surgical workspace and target volume that, ideally, is free from obstacles. The localizer camera 20 may be adjustable in at least one degree of freedom by rotating about a rotational joint, and may be adjustable about two or more degrees of freedom.

[0043] In some implementations, the object to which each tracker 16 is affixed may be rigid and inflexible so that movement of the object cannot or is unlikely to alter the positional relationship between the object and the tracker 16. In other words, the relationship between a tracker 16 in the surgical workspace and an object to which the tracker 16 is attached may remain fixed, notwithstanding changes in the position of theobject within the surgical workspace. For instance, the trackers 16 may be firmly affixed to patient bones such as vertebra V, and to surgical instruments such as retractors and the ultrasonic instrument 15. In this way, responsive to determining a pose of a tracker 16 in the surgical workspace using the localizer camera 20, the navigation controller 24 may infer the pose of the object to which the tracker 16 is affixed based on the determined position of the tracker. In some implementations, the navigation controller 24 may also infer the poses of relatively non-rigid and flexible patient tissues based on the determined poses of other tracked objects adjacent to or having a known relationship to the patient tissues. Additionally or alternatively, the navigation controller 24 may be configured to cooperate with one or more flexible trackers attached to the patient and registered with patient tissue of interest such as non-rigid and flexible patient tissue so as to track such patient tissue in the known coordinate system.

[0044] Referring now to FIG. 5, each tracker 16 may include at least three optical markers 48 that direct light signals to the optical sensors 38 of the localizer camera 20. In some implementations, the markers 48 may be realized as active markers 48 that receive an electrical current from a power source to generate and emit light signals to the optical sensors 38. In this case, the trackers 16 may each be powered by an internal battery, or may have leads to receive power through the navigation controller 24. For instance, the markers 48 may be light emitting diodes (LEDs) that transmit light, such as nonvisible light (e.g., infrared or ultraviolet light), towards the optical sensors 38.

[0045] Each tracker 16 may also include a tracker controller 50 communicatively coupled to the markers 48 and to the navigation controller 24. The tracker controllers 50 may be configured to control the rate and order in which the markers 48 fire, such as at the direction of the navigation controller 24. For example, the tracker controllers 50 may cause the markers 48 of each tracker 16 to fire at different rates and / or times to facilitate differentiation of the markers 48 by the navigation controller 24. In some examples, the navigation controller 24 may form a bi-directional infrared communication channel with each tracker controller 50 to control the timing of the firing of the active marker 48 operated by the tracker controller 50, write / read nonvolatile data, and get the status (e.g., battery level, broken LEDs) of the trackers 16 or the objects to which the trackers 16 are affixed.

[0046] Rather than being active markers, markers 48 of the trackers 16 may be realized as passive markers, such as reflectors that reflect light emitted from the localizer camera 20. To this end, the localizer camera 20 may include a light source 51 (FIG. 1) that illuminates the trackers 16 with light, such as nonvisible light (e.g., infrared or ultraviolet). The markers 48 may then be configured to reflect the light back towards the localizer camera 20, which may then be detected by the optical sensors 38.

[0047] Prior to the start of a surgical procedure using the surgical system 10, pre-operative images may be generated for anatomy of interest, such as anatomical structures defining and / or adjacent a target volume of patient tissue to be treated by the ultrasonic instrument 15. For example, when the target volume of patient tissue to be treated is in the patient’s spine area, pre-operative images of the patient’s spinal column may be taken. These images may be based on MRI scans, radiological scans, or computed tomography (CT) scans of the patient’s anatomy, and may be used to develop virtual models of the anatomical structures, stored as model data 52 in the navigation storage 25.

[0048] Each virtual model for an anatomical structure indicated by the model data 52 may include a three-dimensional model (e.g., point cloud, mesh, CAD) representing the entire or at least a portion of the anatomical structure, and / or may include data indicating a portion of the anatomical structure to be treated, relative to a three-dimensional coordinate system associated with the anatomical structure. These virtual models may be provided to and stored by the navigation controller 24 as model data 52 in advance of a surgical procedure. In addition or alternatively to taking pre-operative images, the above-described virtual models may be generated from kinematic studies, bone tracing (e.g., using a pointer 55 (FIG. 1)), and other methods.

[0049] In addition to virtual models corresponding to the patient’s anatomical structures of interest, prior to the surgical procedure, the navigation controller 24 may receive and store as model data 52 virtual models for other tracked objects of interest, such as the ultrasonic instrument 15 and / or the robotic manipulator 14. The navigation controller 24 may also receive and store as model data 52 a virtual model for each tracker 16 disposed in the surgical workspace, and relationship data 54 for each tracker 16 indicating a positional relationship between the tracker 16 and the object to which the tracker 16 is affixed. Such positional relationship may be defined relative to the virtual models of the tracker 16 andobject. For instance, relative to a given tracker 16 affixed to a vertebra V, the navigation controller 24 may receive relationship data 54 indicating a pose of the coordinate system associated with the vertebra V relative to the coordinate system associated with the tracker 16. In this way, responsive to identifying the pose of the tracker 16 relative to a known coordinate system, the navigation controller 24 may reference the relationship data 54 for the tracker 16 to determine the pose of the coordinate system associated with the vertebra V, and correspondingly of the vertebra V, relative to the known coordinate system.

[0050] In some examples, the positional relationship between each tracker 16 and the object to which the tracker 16 is affixed may be indicated manually via interaction with a patient image depicting the tracker 16 and object on the user interface 28A. Alternatively, the positional relationship between each tracker 16 and the object to which the tracker 16 is affixed may be determined by tracing the object with a pointer 55 (FIG. 1) having its own set of markers 48 that are tracked by the surgical navigation system 12 during the tracing, with the surgical navigation system 12 also concurrently tracking the tracker 16 affixed to the object to correlate a pose of the traced object to a pose of the affixed tracker 16.

[0051] The navigation controller 24 may also receive and store surgical plan data 56 prior to a procedure. The surgical plan data 56 may identify the patient anatomical structures involved in the surgical procedure, may identify the instruments being used in the surgical procedure, and may define the planned trajectories of instruments and the planned movements of patient tissue during the surgical procedure.

[0052] During a surgical procedure, the navigation controller 24 may be configured to operate the localizer camera 20 to cause the optical sensors 38 to generate optical-based signals indicative of detected light signals received from the trackers 16, or more particularly indicative of the image plane positions of the optical sensors 38 in which such light signals were detected. The sampling rate of the optical sensors 38 is the rate at which the optical sensors 38 detect light signals from sequentially fired markers 48. The optical sensors 38 may have sampling rates of 100 Hz or more, or more preferably 300 Hz or more, or most preferably 500 Hz or more. In one instance, the optical sensors 38 may have sampling rates of 8000 Hz.

[0053] Responsive to the optical sensors 38 receiving light signals from the trackers 16, the optical sensors 38 may output optical-based signals indicating the positions of the markers 48 of the trackers 16 relative to the localizer camera 20, which may be used by the navigation controller 24 to determine poses of the objects affixed to the trackers 16 relative to the localizer camera 20. In particular, each optical sensor 38 may include a one- or two- dimensional sensor area (also referred to as an “image plane”) that detects light signals from the trackers 16, and responsively outputs optical-based signals indicating pixel coordinates within the sensor area that each light signal was detected. The optical-based signals output from each optical sensor 38 may thus represent an image of the trackers 16 generated by the optical sensor 38 from the detected light signals, with the image including blobs in pixel coordinates corresponding to the positions in the image plane of the optical sensor 38 that light signals were detected. The detected position of each light signal may be based on the angle at which the light signal is received by the optical sensor 38, and may thus correspond to the position of the marker 48 in the surgical workspace that emitted the detected light signal towards the optical sensor 38.

[0054] The localizer camera 20 may be configured to generate image data based on the optical-based signals received from the optical sensors 38, and communicate such image data to the navigation controller 24. The image data may indicate the image and / or image plane positions represented by the optical-based signals received from each optical sensor 38.

[0055] The navigation controller 24 may be configured to generate tracker pose data indicating the poses of the trackers 16 relative to the localizer camera 20 based on the received image data. More particularly, the navigation controller 24 may determine a position of each marker 48 in the localizer coordinate system LCLZ based on the image data. For instance, the navigation controller 24 may be configured to correlate blobs corresponding to a same optical marker 48 in the image data, triangulate the positions of the optical markers 48 relative to the localizer camera 20 based on the positions of the correlated blobs in the image data and a known positional relationship between the optical sensors 38, and assign the triangulated positions to the markers 48 of each tracker 16 based on a known geometry of the markers 48 of each tracker 16, or alternatively based on a known frequency, timing, or intensity associated with each marker 48. The positions ofthe markers 48 in the localizer coordinate system LCLZ may define the poses of the trackers 16 in the localizer coordinate system LCLZ.

[0056] Based on the poses of the trackers 16 in the known coordinate system, the navigation controller 24 may be configured to generate object pose data indicating the poses of the objects affixed to the trackers 16 in the known coordinate system. Specifically, the navigation controller 24 may apply the previously stored relationship data 54 indicating the positional relationships between the trackers 16 and the objects to which the trackers 16 are affixed to the tracker pose data to determine the poses of the objects fixed to the trackers 16 in the known coordinate system.

[0057] The navigation controller 24 may be configured to track the poses of the objects continuously throughout the surgical procedure, and generate virtual objects in the known coordinate system based on the poses of the tracked objects. The navigation controller 24, such as in cooperation with the ultrasonic resection system 11, may then control operation of the robotic manipulator 14 so as to guide the ultrasonic instrument 15, and / or control operation of the ultrasonic instrument 15 so as to limit resection of non-targeted tissue, based on the virtual objects.

[0058] As described above, the navigation controller 24 may be configured to track the poses of anatomical structures of interest by tracking poses of trackers 16 attached to such structures. Additionally or alternatively, the navigation controller 24 may be configured to track the poses of anatomical structures based on images of the anatomical structures received prior to and / or during the procedure. To this end, the surgical system 10 may include an imaging system coupled to the navigation controller 24 and configured to generate images of patient anatomical structures, such as that described in PCT Application No. PCT / US2023 / 017790. Similar to the ultrasonic instrument 15, the imaging system may include a tracker 16 having a fixed relationship with pixel coordinates of the images generated by the imaging system, which may be stored by the navigation controller 24 as further relationship data 54.

[0059] Prior to and / or during a procedure, the navigation controller 24 may thus receive patient images from the imaging system, and determine a pose of the tracker 16 coupled to the imaging system that corresponds to the images, such as based on data generated by the localizer camera 20 as described herein. The navigation controller 24 may then segmenteach image to determine one or more virtual objects in the coordinate system of the image, and determine the pose of such virtual objects in the known coordinate system, such as the localizer coordinate system LCLZ, based on the pose of the tracker 16 coupled to the imaging system that corresponds to the image and the fixed relationship between the tracker 16 and the coordinate system of the image. The navigation controller 24 may then be configured to control operation of the robotic manipulator 14 and / or ultrasonic instrument 15 based on a tracked position of the distal region 84 of the tip 82, such as via the tracker 16B coupled to the ultrasonic instrument 15, relative to the virtual objects in the known coordinate system.

[0060] Referring again to FIG. 1, the ultrasonic instrument 15 may form pail of an end effector of the robotic manipulator 14. The robotic manipulator 14 may include a base 64, several links 66 extending from the base 64, and several active joints 68 for moving the ultrasonic instrument 15 with respect to the base 64. The links 66 may form a serial arm structure as shown in FIG. 1, a parallel arm structure, or other suitable structure. The robotic manipulator 14 may include an ability to operate in a manual mode in which a user grasps the end effector of the robotic manipulator 14 to cause movement of the ultrasonic instrument 15 (e.g., directly, or through force / torque sensor measurements that cause active driving of the robotic manipulator 14). In this case, at least one of the virtual objects generated by the navigation controller 24 may be a haptic object that generates a force (e.g., positive or negative) on the robotic manipulator 14, such as based on a tracked pose of the ultrasonic instrument 15 relative to the haptic object, so as to guide the user in positioning the ultrasonic instrument 15 to treat the target tissue. Non-limiting examples of haptic objects and corresponding operation of the robotic manipulator 14 based on such objects are described in U.S. Patent Nos. 9,775,681 and 10,398,449, the contents of each of which are hereby incorproated by reference herein in their entirety.

[0061] The robotic manipulator 14 may also include a semi-autonomous mode in which the ultrasonic instrument 15 is moved by the robotic manipulator 14 along a predefined tool path (e.g., the active joints 68 of the robotic manipulator 14 are operated to move the ultrasonic instrument 15 without requiring force / torque on the end effector from the user). An example of operation in a semi-autonomous mode is described in U.S. Patent No. 9,119,655, which is hereby incorporated by reference in its entirety. A separate tracker 16may be attached to the base 64 of the robotic manipulator 14 to also track movement of the base 64 by the localizer camera 20.

[0062] Similar to the surgical navigation system 12, the robotic manipulator 14 may house a manipulator controller 70 configured to implement the functions, features, and processes of the robotic manipulator 14 described herein. During a surgical procedure, the manipulator controller 70 may be configured to determine a desired location to which the ultrasonic instrument 15 should be moved, such as based on navigation data received from the navigation controller 24. Based on this determination, and information relating to the current position of the ultrasonic instrument 15, the manipulator controller 70 may be configured to determine an extent to which the links 66 need to be moved to reposition the ultrasonic instrument 15 from the current position to the desired position. Data indicating where the links 66 are to be repositioned may be forwarded to joint motor controllers (e.g., one for controlling each motor) that control the active joints 68 of the robotic manipulator 14. Responsive to receiving such data, the joint motor controllers may be configured to move the links 66 in accordance with the data, and consequently move the ultrasonic instrument 15 to the desired position.

[0063] Referring now to FIG. 2, the ultrasonic resection system 11 may include a control console 80 and the ultrasonic instrument 15 coupled to the control console 80. The ultrasonic instrument 15 may include a tip 82 with a distal region 84 configured for contacting and treating patient tissue. During operation, the control console 80 may be configured to generate and source an AC drive signal to the ultrasonic instrument 15 that induces ultrasonic energy in the ultrasonic instrument 15, and in turn causes the distal region 84 of the tip 82 to rapidly vibrate. An operator may then position the distal region 84 (also referred to as the tip head 84) of the vibrating tip 82 against patient tissue to resect the contacted tissue. The frequency, amplitude, and velocity of the vibrations of the tip 82 may correspond to that of the sourced AC drive signal.

[0064] The ultrasonic instrument 15 may include a handpiece 86 for being grasped by an operator to maneuver the ultrasonic instrument 15 against patient tissue. The tip 82 may be removably coupled to the handpiece 86 so as to enable the handpiece 86 to be used with different interchangeable tips 82. Different tips 82 removably coupleable to the handpiece 86 may be configured for different types of procedures. For instance, some tips 82removably coupleable to the handpiece 86 may be configured for ablating soft tissue, such as by inducing cavitation in such tissue. A tip 82 configured for ablating soft tissue may define a lumen for providing suction at the surgical site through the tip 82. Some tips 82 removably coupleable to the handpiece 86 may be configured for ablating hard tissue such as fibrous tissue and bone. A tip 82 configured for ablating hard tissue may feature a tip head 84 formed with teeth or flutes dimensioned to remove tissue via a cutting action. Tips 82 removably coupleable to the handpiece 86 may also be of different lengths for providing access to patient anatomy at different depths. Some tips 82 removably coupleable to the handpiece 86 may be designed to only vibrate longitudinally at their tip heads 84, while other tips 82 removably coupleable to the handpiece 86 may be designed to vibrate both longitudinally and torsionally and / or substantially torsionally at their tip heads 84.

[0065] The handpiece 86 may form a proximal end of the ultrasonic instrument 15, and the tip 82 coupled to the handpiece 86 may form a distal end of the ultrasonic instrument 15. “Proximal” may be understood as towards an operator holding the ultrasonic instrument 15 and away from the tissue to which the tip 82 is being applied, and “distal” may be understood as away from the operator and towards the tissue to which the tip 82 of the ultrasonic instrument 15 is being applied.

[0066] Referring now to FIG. 3, the handpiece 86 may include a housing 88 that defines a handle for the operator to grasp and maneuver the ultrasonic instrument 15, and may also include a transducer 90 disposed in a void defined by the housing 88. The transducer 90 may include one or more drivers 92, such as piezoelectric crystals. The drivers 92 may be disc shaped, and may be arranged within the housing 88 end to end in a stack. Each driver 92 may be formed from a material that, upon application of an alternating electrical current, undergoes momentary expansions and contractions along the longitudinal axis of the driver 92, namely, the axis that extends between the proximally and distally directed faces of the driver 92. Insulating discs may be disposed between and tightly abut adjacent drivers 92. The transducer 90 may further include a tube 94, which may extend through the collinear longitudinal axes of the drivers 92.

[0067] A proximal end mass, such as described in U.S. Patent No. 10,16,209, the contents of which are hereby incorporated by reference herein in their entirety, may also be disposed in the void defined the housing 88 and attached to the proximally directed face of the mostproximally located driver 92. In some implementations, the tube 94 may include an exposed proximal end section fixedly attached to the mass. In some examples, the proximal end section of the tube 94 may be threaded, in which case the mass may be a nut.

[0068] The handpiece 86 may also include a horn 96 at least partially disposed within the void defined by housing 88. The horn 96 may be coupled to the distal end of the transducer 90. The horn 96 may be constructed from a rigid steel alloy, titanium or similar material. In operation, as the transducer 90 expands and contracts, the horn 96 may oscillate. The horn 96 may be removably coupled to the transducer 90. For example, the proximal end of the horn 96 may include a threaded male coupler and the distal end of the transducer 90 may include a corresponding female threaded coupler. Alternatively, the transducer 90 and the horn 96 may be permanently coupled via a weld, adhesive, or similar bonding process.

[0069] The tip 82 may be removably couplable to the horn 96. More specifically, the distal end of the horn 96 may include a threaded coupler configured to engage corresponding threads on the proximal end of the tip 82. It is further contemplated that other coupling methods may be utilized to removably couple the tip 82 to the horn 96. For example, the distal end of the horn 96 may comprise features that allow snap fit engagement with the tip 82.

[0070] Referring again to FIG. 2, the ultrasonic instrument 15 may be removably couplable to the control console 80 via a power cable 98, also referred to as an electrical cable 98 herein. One end the electrical cable 98 may be permanently connected to the proximal end of the housing 88 of the ultrasonic instrument 15, and the other end of the electrical cable 98 may include an adapter 100 corresponding to a socket 102 of the control console 80. The socket 102 may be shaped to receive the adapter 100, and may include electrical contacts corresponding to electrical contacts of the adapter 100 such that when the adapter 100 is fully seated in the socket 102, an electrical connection is formed between the ultrasonic instrument 15 and the control console 80.

[0071] Upon actuation of the ultrasonic instrument 15, the control console 80 may generate and source an AC drive signal to the ultrasonic instrument 15 over the electrical cable 98. The ultrasonic instrument 15 may be designed so that the AC drive signal from the control console 80 is applied to each of the drivers 92 of the transducer 90 in parallel, which may cause the drivers 92 to simultaneously expand and contract along a longitudinal axis of thetransducer 90 in accordance with the AC drive signal. The stack of drivers 92 may be between 1 and 5 cm in length. The distance, or amplitude, of movement over a single expansion / contraction cycle of the drivers 92 may be between .01 and 10 microns.

[0072] The horn 96 may be configured to amplify this movement. Consequently, the distal end of the hom 96 and, by extension, the tip 82, may each move back and forth along its longitudinal axis between a fully contracted position to a fully extended position, thereby producing a longitudinal vibrating motion. As some examples, the maximum peak-to-peak vibration of the tip head 84, representing a single movement from the fully contracted position to the fully extended position, may be 1000 microns, or 500 microns, or 300 microns. As previously described, some tips 82 removably coupleable to the handpiece 86 may be configured to vibrate both longitudinally and torsionally and / or substantially torsionally at their tip heads 84. Such a tip 82 may include a feature along its length, such as helical grooves, that is configured to convert at least a portion of the longitudinal vibrations applied to the proximal end of the tip 82 into vibrations at the tip head 84 having both a longitudinal component and a torsional component and / or having substantially only a torsional component.

[0073] Referring now to both FIGS. 2 and 3, to assist in reducing heat generation during an operation, the ultrasonic instrument 15 may define an irrigation pathway for supplying irrigating fluid to the distal region 84 of the tip 82 and the surgical site. To this end, the ultrasonic instrument 15 may include an irrigation sleeve 104 adapted to be disposed around the tip 82 and removably coupled to the handpiece 86, such as the housing 88 of the handpiece 86, for supplying irrigating fluid to at least the distal region 84 of tip 82 and the surgical site.

[0074] The irrigation sleeve 104 may include a sleeve body 106 having open proximal and distal ends and defining a lumen 108 extending between the open proximal and distal ends. The sleeve body 106 may be adapted to be coupled to the handpiece 86, such as the housing 88 of the handpiece 86, so that the tip 82 extends through the lumen 108 and out the open distal end of the sleeve body 106. For instance, the proximal end of the sleeve body 106 may be formed with a coupling feature for releasably coupling the sleeve body 106 to the distal end of the housing 88. When disposed over the tip 82 and coupled to the housing 88, the sleeve body 106 may be radially spaced from the tip 82, and may be spacedlongitudinally away from the tip head 84 as described above. The components of the ultrasonic instrument 15 may be dimensioned so that during normal operation, the tip 82 does not contact the irrigation sleeve 104.

[0075] During operation of the ultrasonic instrument 15, irrigating fluid may be flowed from the handpiece 86, into the gap between the tip 82 and the sleeve body 106, and then out the open distal end of the sleeve body 106. More specifically, the handpiece 86 may include an irrigation conduit 110 running through the housing 88 from the proximal end to the distal end of the handpiece 86. The proximal end of the irrigation conduit 110 may be coupled to a fitting 112 of the ultrasonic instrument 15 that extends from a proximal end of the handpiece 86 for receiving an irrigation line 114. The irrigation line 114 may be coupled to a fluid supply 116 via a cassette 118, which may be configured to be inserted into a corresponding slot 120 of the control console 80. During operation of the ultrasonic resection system 11, a pump 122 of the control console 80 may operate on the cassette 118 to draw fluid from the fluid supply 116 into the irrigation line 114 and thereafter into the irrigation conduit 110.

[0076] The irrigation sleeve 104 may similarly include an irrigation conduit 124 in fluid communication with the lumen 108 defined by the sleeve body 106. The irrigation conduit 124 may extend from the proximal end of the sleeve body 106 and run adjacent the lumen 108 to an aperture 126 formed in a wall of the lumen 108. The aperture 126 may be positioned at an intermediate position between the proximal and distal ends of the lumen 108, and may be configured to supply irrigating fluid from the irrigation conduit 124 into the gap between the tip 82 and the sleeve body 106. The proximal end of the irrigation conduit 124 of the irrigation sleeve 104 may be adapted to fluidly engage the distal end of the irrigation conduit 110 of the handpiece 86 when the irrigation sleeve 104 is coupled to the handpiece 86.

[0077] Accordingly, during operation of the ultrasonic instrument 15, irrigating fluid may flow from a fluid supply 116, through the irrigation line 114, fitting 112, and conduits 110, 124, and out the aperture 126 into the lumen 108. Such irrigating fluid may then run distally down the lumen 108 and out the open distal end of the sleeve body 106. In alternative examples, rather than being configured to receive irrigating fluid through the handpiece 86, the irrigation sleeve 104 may include a fitting in fluid communication withthe irrigation conduit 124 and disposed on an outer surface of the sleeve body 106 for receiving the irrigation line 114 running outside of the handpiece 86. In this case, during operation of the ultrasonic instrument 15, irrigating fluid may be similarly flowed through the gap between the tip 82 and the sleeve body 106 via the fitting and out the open distal end of the sleeve body 106.

[0078] The ultrasonic instrument 15 may also define an aspiration pathway for providing suction at a surgical site through the distal region 84 of the tip 82. For instance, the tube 94 of the transducer 90 may define a lumen extending from the proximal end to the distal end of the transducer 90 to create a fluid passageway through the transducer 90. The horn 96 may similarly define a lumen extending from the proximal end to the distal end of the horn 96 to create a fluid passageway through the horn 96, and the tip 82 may also define a lumen extending from the proximal end to the distal end of the tip 82 to create a fluid passageway through the tip 82. Collectively, these lumens may form at least a portion of an aspiration pathway that extends from the distal region 84 of the tip 82 to the proximal end of the handpiece 86.

[0079] The ultrasonic instrument 15 may further include a fitting 128 coupled to the tube 94 and extending proximally from the proximal end of the handpiece 86 for receiving a suction line 130. During a procedure, suction may be applied to the fluid pathway defined by the tube 94, horn 96, and tip 82 via the fitting 128 and suction line 130 to draw the irrigating fluid applied to the surgical site and debris formed by a procedure that is entrained in the fluid towards and out of the proximal end of the handpiece 86. More specifically, the control console 80 may include a vacuum pump 132 in fluid communication with a waste canister 134 via the cassette 118 when inserted in the control console 80, with the waste canister 134 being separately placed in fluid communication with the fluid passageway defined by the tube 94, horn 96, and tip 82 via a fluid passageway defined by the fitting 128, suction line 130, and cassette 118. In this way, the vacuum pump 132 may apply a suction to the fluid passageway defined by the tube 94, horn 96, and tip 82 via the waste canister 134, fitting 128, suction line 130, and cassette 118, thereby drawing materials from the surgical site through the aforementioned fluid passageways into the waste canister 134. The suction may also function to draw tissue towards the tip head 84, which may enhance the effectiveness of the tip 82 in treating patient tissue.

[0080] The control console 80 may also include a user interface 28B (FIG. 5) for receiving user input and providing information to the user. For instance, the control console 80 may include a display 136 for presenting information to the practitioner that forms a component of the user interface 128B. Non-limiting examples of presented information may include an identification of the ultrasonic instrument 15, or more particularly of the handpiece 86 and / or tip 82, currently connected to the control console 80, and an operating state of the ultrasonic resection system 11. The display 136 may be a touch screen display that enables the practitioner to provide input to the control console 80, such as via on-screen control elements.

[0081] An operator may interact with the on-screen control elements to set operational parameters of the ultrasonic resection system 11, such as an ultrasonic energy level, a suction level, an irrigation level, and / or a pulsing level for the ultrasonic instrument 15, such as described in PCT Publication No. WO 2022 / 072903 Al, the entire contents of which are hereby incorporated by reference. In some implementations, the control console 80 may be configured to determine a predefined maximum level for one or more of these operational parameters, such as based on data read from the ultrasonic instrument 15 when connected to the control console 80, and the settings for each such operational parameter input by the practitioner may indicate a percentage of the predefined maximum level to use for the ultrasonic instrument 15 relative to the operational parameter. An operator may also interact with on-screen control elements to select a given type of procedure and / or a set of one or more tissue types involved in a given aspect of a procedure, as described in more detail below.

[0082] The user interface 128B of the ultrasonic resection system 11 may also include one or more actuation devices coupled to the control console 80. Upon activation by the practitioner, each of the actuation devices may cause the control console 80 to generate and source the AC drive signal to the ultrasonic instrument 15 that induces ultrasonic energy in the ultrasonic instrument 15 to vibrate the tip 82.

[0083] For instance, the one or more actuation devices may include a foot pedal 138. The foot pedal 138 may be wirelessly connected to the control console 80, such as via an adapter 140 connected to the control console 80. Upon being depressed, the foot pedal 138 may transition from an off position to an active position, and may communicate a correspondingsignal to the control console 80 that indicates the depression. In some instances, the communicated signal may also vary with the extent to which the foot pedal 138 is depressed, such as to enable the practitioner to vary a target ultrasonic energy level (e.g., target power level) for the ultrasonic instrument 15 up to a maximum ultrasonic energy level for the ultrasonic instrument 15. The maximum ultrasonic energy level for the ultrasonic instrument 15 may be a predefined maximum level for the ultrasonic instrument 15, such as indicated by data read from the ultrasonic instrument 15, or to a practitionerset maximum level, such as a percentage of the predefined maximum level as described above. Responsive to receiving the actuation signal, the control console 80 may generate and source an AC drive signal to the ultrasonic instrument 15 that causes the tip 82 to vibrate according to the current settings of the control console 80 and / or the extent of the depression indicated by the actuation signal.

[0084] The user interface 128B of the ultrasonic resection system 11 may also include a remote control 142 coupled to the control console 80. Similar to the display 136, the remote control 142 may provide practitioner-selectable elements for enabling practitioner input to the control console 80. For instance, the remote control 142 may include buttons for setting the operational parameters of the ultrasonic resection system 11, such as the ultrasonic energy level, suction level, irrigation level, and / or pulsing level for the ultrasonic instrument 15. The remote control 142 may also include a main power switch for turning on and off the control console 80. Additionally, or alternatively, the control console 80 may include a main power switch 144 for turning on and off the control console 80.

[0085] FIGS. 4A and 4B show circuits illustrating the flow of current through the ultrasonic instrument 15 when an AC drive signal is sourced to the ultrasonic instrument 15 from the control console 80. As shown in the illustrated examples, the current isof the sourced AC drive signal may be broken down into two components: a current ioapplied to the drivers 92 of the ultrasonic instrument 15 and an equivalent of current iMapplied to the mechanical components of the ultrasonic instrument 15 (also referred to herein as “mechanical current iM”). The mechanical components of the ultrasonic instrument 15 may include those components that vibrate in response to the sourced AC drive signal to treat patient tissue, such as and without limitation, the drivers 92, tube 94, horn 96, tip 82, and proximal end mass described above.

[0086] The impedance Zoprovided by the drivers 92 may be primarily capacitive. Accordingly, the drivers 92 may be represented by a capacitor with capacitance Co. The capacitance Coof the drivers 92 may remain substantially constant during operation of the ultrasonic instrument 15, and may thus be determined and provided to the control console 80 in advance of an operation, such as upon connection of the ultrasonic instrument 15 to the control console 80, so as to tailor operation of the control console 80 to the specific handpiece 86 of the ultrasonic instrument 15. Additionally or alternatively, the control console 80 may be configured to periodically measure the capacitance Coof the driver 26 during operation of the ultrasonic instrument 15 to enable even further precision.

[0087] The equivalent of impedance ZMprovided by the mechanical components of the ultrasonic instrument 15 (also referred to herein as “mechanical impedance ZM”) may include an inductive component, a resistive component, and a capacitive component. Accordingly, the mechanical components may be represented by an inductor with inductance LM, a resistor with resistance RM, and a capacitor with capacitance CM. The mechanical impedance ZMmay vary with operation of the ultrasonic instrument 15. For instance, at least the resistance RM(also referred to herein as “mechanical resistance RM”) may vary as a function of mechanical damping imposed by tissue contacted by the distal region 84 of the tip 82, and at least the capacitance CMmay vary as a function of the mechanical stiffness of tissue contacted by the distal region 84 of the tip 82. In some implementations, the mechanical impedance ZMmay therefore be used to determine whether the distal region 84 of the tip 82 is loaded with tissue, as described in more detail below.

[0088] The ultrasonic energy induced in the ultrasonic instrument 15, and correspondingly the vibrations of the tip 82, may be proportional to the mechanical current iMinduced in the ultrasonic instrument 15. More specifically, the frequency of the vibrations at the tip head 84 may be equal to the frequency of the mechanical current iM, and the amplitude of the vibrations may be proportional to the amplitude of the mechanical current iM. For instance, when the ultrasonic instrument 15 is operating at resonance, the peak-to-peak displacement of the tip head 84 in microns may be approximately 180% to 220% of the amplitude of the mechanical current iMin milliamps, depending on the gain of the tip 82. As an example, a mechanical current iMat the resonant frequency of the ultrasonicinstrument 15 and with an amplitude of 150 milliamps may induce the tip head 84 of a given tip 82 to vibrate back and forth along a path of travel that is approximately 330 microns. The control console 80 may thus cause vibrations in the tip 82 with a target frequency and displacement level by sourcing an AC drive signal to the ultrasonic instrument 15 that induces a mechanical current iMin the ultrasonic instrument 15 with the target frequency and an amplitude corresponding to the target displacement level.

[0089] Referring again to FIG. 5, the control console 80 may include an ultrasonic controller 150, console storage 152, and a power supply 154 for generating the AC drive signal sourced to the ultrasonic instrument 15, such as according to control signals from the ultrasonic controller 150. Specifically, the ultrasonic controller 150 may be configured to assert control signals to the power supply 154 that regulate the frequency and voltage of the AC drive signal output to the ultrasonic instrument 15.

[0090] The power supply 154 may include a DC supply 156, an amplifier 158, and a transformer 160. During operation of the ultrasonic resection system 11, the DC supply 156 may output a DC signal to a center tap of a primary winding 162 of the transformer 160. The opposed ends of the transformer primary winding 162 may be tied to the amplifier 158, which may be configured to develop an AC signal across the primary winding 162 from the applied DC signal by applying varying levels of resistance to the ends of the transformer primary winding 162. The AC signal developed across the primary winding 162 may induce a proportional AC drive signal across a secondary winding 164 of the transformer 160, which may be coupled to the ultrasonic instrument 15 through electrical contacts 166. A further understanding of the assemblies of the power supply 154 can be found in PCT Publication No. WO 2016 / 183084 Al, the contents of which are hereby incorporated by reference herein in their entirety.

[0091] As illustrated in FIG. 6, the electrical contacts 166 may be integral with the socket 102 of the control console 80. Corresponding electrical contacts 168 may be integral with the adapter 100 of the electrical cable 98. When the adapter 100 is fully seated in the socket 102, the electrical contacts 166, 168 may become aligned and form an electrical path over which the AC drive signal across the secondary winding 164 of the transformer 160 is sourced to the ultrasonic instrument 15 to vibrate the tip 82. The drivers 92 may be disposed within the handpiece 86 so that the AC drive signal is applied to each of the drivers92 in parallel, and thereby causes vibrations of the tip 82 according to the received AC drive signal.

[0092] Referring again to FIG. 5, the ultrasonic controller 150 may be configured to implement the functions, features, processes, and methods of the control console 80 described herein. For instance, the ultrasonic controller 150 may be configured to determine whether to operate the ultrasonic instrument 15 in a tissue sense mode or a tissue resection mode, and to regulate the AC drive signal developed across the secondary winding 164 accordingly. The ultrasonic controller 150 may be configured to regulate the AC drive signal developed across the secondary winding 164 by regulating the AC signal developed across the primary winding 162, such as by supplying a control signal to the DC supply 156 that sets the potential of the signal applied to the center tap of the primary winding 162, and / or by supplying a control signal to the amplifier 158 that corresponds to a target AC drive signal to be developed across the secondary winding 164.

[0093] For instance, the ultrasonic controller 150 may be configured to induce a target AC drive signal across the secondary winding 164 by supplying a control signal to the amplifier 158 that includes at least one frequency corresponding to that of the target AC drive signal, and at least one amplitude proportional to that of the target AC drive signal. In some implementations, the ultrasonic controller 150 may be configured with a digital signal synthesis (DDS) component for generating the control signal. Responsive to receiving the control signal, the amplifier 158 may be configured to develop an AC signal across the primary winding 162 that is proportional to the target AC drive signal, which in turn may induce the target AC drive signal across the secondary winding 164 for being sourced to the ultrasonic instrument 15. By regulating the AC signals developed across the primary winding 162 and secondary winding 164 of the transformer 160 in this manner, the ultrasonic controller 150 may be configured to control both the frequency and amplitude of the vibrations of the tip 82.

[0094] In some implementations, the ultrasonic controller 150 may be configured to source a pulsed AC drive signal to the ultrasonic instrument 15, such that the amplitude of the AC drive signal varies between an upper amplitude and a lower amplitude as a function of time. To this end, the ultrasonic controller 150 may be configured to generate, such as using DDS, a base AC signal with an ultrasonic frequency and a constant amplitude, and amodulation signal for amplitude modulating the base AC signal. The ultrasonic controller 150 may then be configured to combine the signals, such as using a multiplier, to generate a control signal for the power supply 154 that corresponds to the target pulsed AC drive signal.

[0095] The ultrasonic controller 150 may be configured to determine whether to initiate vibration of the tip 82 of the ultrasonic instrument 15 by monitoring the state of the foot pedal 138. Responsive to the foot pedal 138 being depressed, the ultrasonic controller 150 may be configured to cause the power supply 154, such as via a corresponding control signal from the ultrasonic controller 150, to source an AC drive signal to the ultrasonic instrument 15 that corresponds to a target ultrasonic energy level for the ultrasonic instrument 15, such as determined as a function of the extent of depression of the foot pedal 138, settings of the control console 80, a predefined maximum ultrasonic instrument level for the ultrasonic instrument 15, and / or an operational mode of the ultrasonic resection system 11 as described herein.

[0096] As previously described, the ultrasonic controller 150 may be configured to cause vibrations in the tip 82 with a target frequency and displacement level by generating a control signal to the power supply 154 that causes the power supply 154 to source an AC drive signal to the ultrasonic instrument 15 that induces a mechanical current iMin the ultrasonic instrument 15 with the target frequency and an amplitude corresponding to the target displacement level. To this end, the ultrasonic controller 150 may be configured to implement two control loops to induce target vibrations in the tip 82, namely, a control loop for regulating the frequency of the mechanical current iMinduced in the ultrasonic instrument 15 by the AC drive signal, and a control loop for regulating the level (e.g., amplitude) of the mechanical current iMinduced in the ultrasonic instrument 15 by the AC drive signal. Each control loop may incorporate a PID controller for efficiently adjusting the AC drive signal to achieve the desired values, and may have an iterative loop time of approximately 400 microseconds.

[0097] Using Ohm’s law, the ultrasonic controller 150 may be configured to calculate the level of mechanical current iMinduced in the ultrasonic instrument 15 using the following Equation: i-M = U -j2nfCovs(1)where isis the current of the AC drive signal being sourced to the ultrasonic instrument 15, f is the frequency of the AC drive signal being sourced to the ultrasonic instrument 15, Cois the capacitance of the drivers 92, and vsis the voltage of the AC drive signal being sourced to the ultrasonic instrument 15. An explanation for Equation (1) is provided in Applicant’s U.S. Patent No. 10,16,209, the contents of which are hereby incorporated by reference herein in their entirety. Assuming the frequency f of the AC drive signal has been previously set to achcivc a target vibratory characteristic of the ultrasonic instrument 15 (e.g., resonance), the ultrasonic controller 150 may induce a target level of mechanical current iM, and correspondingly target vibrations of the tip 82, by setting the voltage vsof the AC drive signal so that Equation (1) results in the target level of mechanical current iM.

[0098] As mentioned above, a characteristic integral with the ultrasonic instrument 15 is the resonant frequency of the ultrasonic instrument 15. The resonant frequency may be a frequency at which the distal region 84 of the tip 82 undergoes vibratory motions of a peak range. In other words, assuming other electrical characteristics remain constant, at the resonant frequency, the tip 82 may undergo a motion that is larger in magnitude than a motion that would occur if the drivers 92 were vibrated at a frequency less than or greater than the resonant frequency. For a tip 82 that vibrates longitudinally, the peak range may be understood as the largest back and forth distance of the distal end of the tip 82. The resonant frequency of the ultrasonic instrument 15 may vary during operation of the ultrasonic instrument 15.

[0099] The ultrasonic controller 150 may be configured to regulate the frequency of the AC drive signal during operation of the ultrasonic instrument 15 to track a target vibrational characteristic of the ultrasonic instrument 15 such as resonance. Applicant’s U.S. Patent No. 10,16,209 discloses one exemplary means for regulating the frequency of the AC drive signal to track a resonant frequency of the ultrasonic instrument 15. In particular, the ultrasonic instrument 15 may be considered as operating at resonance when the real part of the ratio of the current iothrough the drivers 30 to the mechanical current iMis substantially equal to zero. The ultrasonic controller 150 may thus be configured to determine a value for the frequency f of the AC drive signal such that the following Equation is true:where isis the current of the AC drive signal sourced to the ultrasonic instrument 15 and Cois the capacitance of the drivers 92. Responsive to determining such value, the ultrasonic controller 150 may be configured to set the frequency of the AC drive signal to the value, thereby causing the ultrasonic instrument 15 to operate at or near resonance. Each value to which the frequency of the AC drive signal is regulated to track a resonant frequency of the ultrasonic instrument 15 may generally be referred to as a determined or calculated resonant frequency of the ultrasonic instrument 15.

[0100] The ultrasonic controller 150 may additionally or alternatively be configured to regulate the frequency of the AC drive signal to track a resonant frequency of the ultrasonic instrument 15 using other means. For instance, the ultrasonic controller 150 may be configured to determine a value for the frequency of the AC drive signal such that the phase difference between the current isof the AC drive signal and the voltage vsthe AC drive signal is approximately zero, such as by implementing a phase lock loop (PLL) for these signals. Additionally or alternatively, the ultrasonic controller 150 may be configured to target an alternative vibratory characteristic of the ultrasonic instrument 15 other than resonance, such as an anti-resonant frequency of the ultrasonic instrument 15 (in which case the right hand side of Equation (2) may be set to 1, as an example) or to a target frequency between the resonant and anti-resonant frequencies.

[0101] As the frequency of the AC drive signal is adjusted to follow a target vibratory characteristic of the ultrasonic instrument 15 such as resonance, the level of the mechanical current iMinduced in the ultrasonic instrument 15 may vary. Accordingly, to induce target ultrasonic energy in the ultrasonic instrument 15, the ultrasonic controller 150 may be configured to repeatably alternate between or perform in parallel the operations of regulating the frequency of the AC drive signal to a target vibratoiy characteristic, such as based on Equation (2), and setting the voltage vsof the AC drive signal so that the mechanical current iM, such as calculated according to Equation (1), corresponds to the target ultrasonic energy level.

[0102] To this end, the ultrasonic controller 150 may be configured to receive feedback data corresponding to the AC drive signal sourced to the ultrasonic instrument 15, such as via one or more sensors of the control console 80. For example, the control console 80 may include a sensor for measuring a voltage vsof the AC drive signal sourced to theultrasonic instrument 15, which may include a tickler coil 174 integral with the transformer 160. The ticker coil 174 may be connected to a voltage measuring circuit 176 of the control console 80, which in turn may be connected to the ultrasonic controller 150. The signal across ticker coil 174 may have a known relationship to the voltage vsof the AC drive signal being sourced to the ultrasonic instrument 15. Based on the signal across the ticker coil 174, the voltage measuring circuit 176 may generate and communicate a signal to the ultrasonic controller 150 representative of the potential and phase of the voltage vsof the AC drive signal being applied to the ultrasonic instrument 15. The ultrasonic controller 150 may thus be configured to measure the voltage vsof the sourced AC drive signal via the voltage measuring circuit 176 and ticker coil 174, and to take actions based thereon.

[0103] As a further example, the control console 80 may include a sensor for measuring a current isof the AC drive signal being sourced to the ultrasonic instrument 15, which may include a coil 178 located in close proximity to one of the conductors that extends from the secondary winding 164 of the transformer 160 to the ultrasonic instrument 15. The coil 178 may be connected to a current measuring circuit 180 of the control console 80, which in turn may be connected to the ultrasonic controller 150. The signal across the coil 178 may have a known relationship to the current isof the AC drive signal being sourced to the ultrasonic instrument 15. Based on the signal across coil 178, the current measuring circuit 180 may produce and communicate to the ultrasonic controller 150 a signal representative of the magnitude and phase of the current isof the AC drive signal being applied to the ultrasonic instrument 15. The ultrasonic controller 150 may thus be configured to measure the current isof the sourced AC drive signal via the current measuring circuit 180 and coil 178, and to take action based thereon.

[0104] As described above, the ultrasonic controller 150 may be configured to regulate the frequency and voltage vsof the sourced AC drive signal based on the obtained measurements of the voltage vsand / or current isof the AC drive signal. Further during operation of the ultrasonic instrument 15, the control console 80, or more particularly the ultrasonic controller 150, may be configured to determine whether the ultrasonic instrument 15 is in a loaded state (e.g., contacting patient tissue) based on obtained measurements of the voltage vsand / or the current isof the sourced AC drive signal, and if so, utilize a set frequency of the AC drive signal (e.g., determined resonant frequency ofthe ultrasonic instrument 15) to determine a type of the contacted tissue. The ultrasonic controller 150, such as in cooperation with the navigation controller 24 and / or manipulator controller 70, may then be configured to adjust operation of the surgical system 10 based on the determined tissue type, such as according to a predefined ultrasonic energy profile associated with the determined tissue type within the console storage 152 or navigation storage 25.

[0105] For example and without limitation, responsive to determining a tissue type corresponding to tissue targeted for resection, the ultrasonic controller 150 may be configured to transition operation of the ultrasonic instrument 15 from the tissue sense mode to the tissue resection mode. Conversely, responsive to determining a tissue type corresponding to tissue that is not targeted for resection, the ultrasonic controller 150 may be configured to transition operation of the ultrasonic instrument 15 from the tissue resection mode to the tissue sense mode. Additionally or alternatively, responsive to determining a tissue type corresponding to tissue that is targeted for resection but located near a critical structure or other non-targeted tissue, such as when the ultrasonic instrument 15 is resecting a bone and about to break through an outer wall of the bone, the ultrasonic controller 150 may be configured to cease operation of the ultrasonic instrument 15, or operate the ultrasonic instrument 15 in the tissue resection mode but at a reduced power level, such as by reducing the target ultrasonic energy level and / or pulsing the AC drive signal so as to induce vibratory pulses extending between a set target ultrasonic energy level and a lower level, for instance as disclosed in PCT Application No. PCT / US2023 / 017790.

[0106] Additionally or alternatively, as described above, the navigation controller 24 may be configured to track a pose of the ultrasonic instrument 15, or more particularly a position of the distal region 84 of the tip 82, relative to a virtual object associated with patient tissue in a known coordinate system, such as to display guidance, control operation of the ultrasonic instrument 15, and / or control movement of the robotic manipulator 14 based on the tracked pose. The virtual object may generally correspond to a boundary of one or more tissue types. Correspondingly, responsive to a determination of contact by the ultrasonic instrument 15 with a given tissue type, the navigation controller 24, in cooperation with the ultrasonic controller 150 of the ultrasonic resection system 11, maybe configured to determine whether the determined tissue type corresponds to that indicated by the tracked position of the distal region 84 of the tip 82 relative to the virtual object. If not, then the navigation controller 24 may be configured to adjust a parameter (e.g., shape, position, pose) of the virtual object in the known coordinate system based on the determined tissue type, such that the adjusted virtual object represents the determined tissue type in the corresponding tracked position of the distal region 84 of the tip 82.

[0107] As described above, in some implementations, one or more of the virtual objects may be haptic objects for controlling the robotic manipulator 14, such as to guide movement of the ultrasonic instrument 15. In this case, the navigation controller 24 may be configured to adjust a parameter of the virtual object based on the determined tissue type by adjusting a position, pose, and / or torque / force associated with the haptic object based on the determined tissue type, as described in more detail below.

[0108] As a further example, responsive to the determined tissue type corresponding a patient anatomy of interest (e.g., bone), the navigation controller 24 may be configured to automatically begin tracing the patient anatomy by tracking the movement of the distal region 84 of the tip 82, such as so long as the determined tissue type continues to correspond to the patent anatomy of interest, so as generate a virtual model of the patient anatomy.

[0109] Additionally or alternatively, the navigation controller 24 may be configured to cooperate with the ultrasonic controller 150 to track a resection status of a surgical procedure based on the determined tissue types indicated by the ultrasonic controller 150 and the tracked poses of the ultrasonic instrument 15 corresponding to the determined tissue types. More specifically, based on the tissue types determined with the ultrasonic instrument 15, the navigation controller 24 may be configured to calculate an estimated volume of tissue targeted for resection that has been resected with the ultrasonic instrument 15, and compare the calculated volume to a planned resection volume, such as determined based on preoperative images of the target site. The navigation controller 24 may then be configured to display the resection status via the user interface 28A, such as in the form of a percentage, or a graphic showing a virtual model or patient image corresponding to the target site with highlighting indicative of portions of the target volume that been resected and / or portions not yet resected.

[0110] The console storage 152 may store data supporting the functions, features, processes, and methods of the control console 80, or more particularly of the ultrasonic controller 150, described herein. For example and without limitation, the console storage 152 may store waveform data 170 and tissue type data 172. The waveform data 170 may include one or more DDS arrays each representative of a different waveform, such as a sine waveform, and may be utilized by the ultrasonic controller 150 to generate control signals as described above. The tissue type data 172 may map varying potential operating characteristics of the ultrasonic instrument 15, such as related to determined resonant frequencies of the ultrasonic instrument 15, with varying types of tissue, such as by indicating one or more thresholds for determining the type of tissue being contacted by the distal region of the tip 82. Examples of the tissue type data 172 are described in more detail below.

[0111] The control console 80 may also include a memory reader 182 for communicating with one or more electronic memory storage devices integral with the ultrasonic instrument 15. The ultrasonic instrument 15 may include one or more electronic memory storage devices for storing data that identifies the ultrasonic instrument 15, or more particularly the handpiece 86 and / or tip 82. The stored data may also define operational data specific to the ultrasonic instrument 15, or more particularly the handpiece 86 and / or tip 82. Nonlimiting examples of operational data may include a maximum current for the sourced AC drive signal, a maximum mechanical current iMfor the sourced AC drive signal, a maximum voltage for the sourced AC drive signal, minimum and maximum frequencies for the sourced AC drive signal, PID coefficients for regulating the sourced AC drive signal, a capacitance of the drivers 92, and a use history. In some implementations, the operational data may also include data indicating whether the ultrasonic instrument 15, or more particularly the handpiece 86 and / or tip 82, is enabled for tissue sense mode and / or tissue resection mode with a sensing function, and data specific to the ultrasonic instrument 15 for facilitating such modes, as described in more detail below.

[0112] For instance, referring again to FIG. 6, the handpiece 86 of the ultrasonic instrument 15 may include a handpiece (HP) memory 184 disposed therein. As non-limiting examples, the HP memory 184 may be an EPROM, an EEPROM, or an RFID tag. Responsive to connecting the ultrasonic instrument 15 to the control console 80, the ultrasonic controller150 may be configured to read the data stored in the HP memory 184 using the memory reader 182, and to tailor operation of the control console 80 based on the read data. More particularly, the control console 80 may include a communication interface, such as a coil 186, connected to the memory reader 182. The coil 186 may be integral with the socket 102 of the control console 80. The HP memory 184 may similarly be connected to a coil 188, which may be integral with the adapter 100 of the cable 98. When the ultrasonic instrument 15 is connected to the control console 80 via the power cable 98, the coils 186, 188 may become aligned and able to inductively exchange signals. The ultrasonic controller 150 may then be configured to read data from and write data to the HP memory 184 over the coils 186, 188.

[0113] More particularly, the memory reader 182 may be configured to convert signals across the coil 186 into data signals readable by the ultrasonic controller 150. The memory reader 182 may also be configured to receive data to be written to the HP memory 184 from the ultrasonic controller 150, and to generate a signal across the coil 186 that causes the data to be written to the HP memory 184. The structure of the memory reader 182 may complement that of the HP memory 184. Thus, continuing with the above non-limiting examples, the memory reader 182 may be an assembly capable of reading data from and writing data to an EPROM, EEPROM, or RFID tag.

[0114] In addition or alternatively to the HP memory 184, the ultrasonic instrument 15 may include a tip memory 190. As described above, the tip 82 may be removable from the handpiece 86 so the handpiece 86 can be used with varying interchangeable tips 82, and different tips 82 may have different structural characteristics and operational limitations. Accordingly, the HP memory 184 may store data identifying the handpiece 86 and operational parameters specific to the handpiece 86, including the capacitance of the drivers 92 and operational parameters specific to the secondary drive component of the sourced AC drive signal (which may be powered through the handpiece 86), and the tip memory 190 may store data identifying the tip 82 currently coupled to the handpiece 86 and operational parameters specific to the tip 82. Because the tip 82 and sleeve 42 may be distributed together as a single package, the tip memory 190 may be disposed in the sleeve 42. To the extent the ultrasonic instrument 15 is sense enabled, the tip memory 190 may also store tissue type data 172A and tissue sense data 191 that is specific to the tip 82, asdescribed in more detail below. The tip memory 190 may be the same type of memory as the HP memory 184 (c.g., an EPROM, an EEPROM, or an RFID tag).

[0115] Responsive to connecting the ultrasonic instrument 15 to the control console 80, the ultrasonic controller 150 may thus be configured to read the data stored in the HP memory 184 and the tip memory 190 using the memory reader 182, and to tailor operation of the control console 80 to the specific handpiece 86 and tip 82 combination coupled to the control console 80. In some instances, the tip memory 190 may include values for the same operational parameters as the HP memory 184. To the extent the values for a given operational parameter differ between the HP memory 184 and the tip memory 190, the ultrasonic controller 150 may be configured to utilize the more restrictive value to manage operation of the ultrasonic instrument 15. Additionally or alternatively, to the extent the both the HP memory 184 and the tip memory 190 include a value for a given operational parameter, the ultrasonic controller 150 may be configured to derive a value (e.g., max current for the main drive component of the AC drive signal) to manage operation of the ultrasonic instrument 15 based on a combination of the values stored in the memories (e.g., summing or averaging the values).

[0116] Similar to the HP memory 184, the ultrasonic controller 150 may read data from and write data to the tip memory 190 via the memory reader 182 and coil 186. In particular, the handpiece 86 may include two conductors 192 extending from the proximal region to the distal region of the handpiece 86. The proximal ends of the conductors 192 may be coupled to the coil 188, which may be integral with the adapter 100 of the electrical cable 98. The distal ends of the conductors 192 may be coupled to another coil 194 disposed at the distal region of the handpiece 86. A corresponding coil 196 may be disposed in a proximal region of the sleeve 42. When the sleeve 42 is disposed around the tip 82 and fitted to the handpiece 86, the coils 194, 196 may become aligned and able to inductively exchange signals. When the handpiece 86 is connected to the control console 80 via the cable 98, the coils 186, 188 may also become aligned and able to inductively exchange signals. The ultrasonic controller 150 may then read data from and write data to the tip memory 190 over the conductors 192 via inductive communication provided by the coils 186, 188 and the coils 194, 196.

[0117] Referring again to FTG. 5, the ultrasonic controller 150 may also be coupled and configured to drive the display 136 of the control console 80, and may be coupled to the remote control 142. As previously described, the ultrasonic controller 150 may be configured to generate information and user interface (UI) components for presentation on the display 136, and when the display 136 is a touch screen display, the ultrasonic controller 150 may also be configured to cause the display 136 to depict images of buttons and other user-selectable components for setting desired operating parameters for the ultrasonic resection system 11. The remote control 142 may likewise include user- interactable elements for setting desired operating parameters of the ultrasonic resection system 11 from a position remote from the control console 80.

[0118] FIGS. 7 and 8 illustrate processes 700, 800 for sensing and resecting tissue using the ultrasonic instrument 15. The processes 700, 800 may be implemented by the one or more controllers of the surgical system 10. While the below description refers to determining frequencies corresponding to a resonant frequency of the ultrasonic instrument 15, it will be understood that other target vibratory characteristics of the ultrasonic instrument 15 may be used.

[0119] Referring first to FIG. 7, at block 702, data may be read from the ultrasonic instrument 15, or more particularly from the HP memory 184 and / or tip memory 190 of the ultrasonic instrument 15, such as by the ultrasonic controller 105. As described above, the read data may indicate a capacitance of the at least one driver 92, a maximum mechanical current iMfor the ultrasonic instrument 15, tissue type data 172A, and / or tissue sense data 191. The tissue type data 172A may indicate an unloaded resonant frequency of the ultrasonic instrument 15, that is, an expected resonant frequency of the ultrasonic instrument 15 when the tip 82 is vibrating in free air and / or not vibrating against tissue. Additionally or alternatively, the tissue type data 172A may include data mapping varying potential operating characteristics of the ultrasonic instrument 15, such as related to determined resonant frequencies of the ultrasonic instrument 15, with varying types of tissue, such as by indicating one or more thresholds specific to the tip 82 for determining the type of tissue being contacted by the distal region 84 of the tip 82 as a function of determined resonant frequency. The tissue sense data 191 may indicate one or more parameters (e.g., target mechanical current iM, pulsing parameters) for the AC drive signalsourced to the ultrasonic instrument 15 in at least the tissue sense mode, such as for each of different tissue types and / or procedure types selectable by the operator. The ultrasonic controller 150 may be configured to read such data from the ultrasonic instrument 15, and temporarily store such data in the console storage 152 for regulating operation of the ultrasonic instrument 15. To this end, reference to the tissue type data 172 below may refer to the tissue type data 172A that has been read from the ultrasonic instrument 15.

[0120] At block 704, objects of interest, such as the distal region 84 of the tip 82 of the ultrasonic instrument 15 and patient tissue in and around a target site, may be tracked in a known coordinate system, such as the localizer coordinate system LCLZ, and such as by the navigation controller 24 in cooperation with a tracker 16 disposed relative to each object as described above. Virtual objects corresponding to the tracked objects of interest may then be generated in the known coordinate system.

[0121] At block 706, a determination may be made of whether the ultrasonic instrument 15 is actuated, such as by the ultrasonic controller 150. For instance, the ultrasonic controller 150 may be configured to monitor for depression of the foot pedal 138, as described above.

[0122] At block 708, a determination may be made of whether to operate the ultrasonic instrument 15 in a tissue resection mode or a tissue sense mode. As previously described, the tissue resection mode may cause vibrations in the tip 82 that are configured for ablating the patient tissue. Conversely, the tissue sense mode may cause vibrations in the tip 82 that are configured for detecting a type of tissue being contacted by the distal region 84 of the tip 82 without causing resection. In some implementations, the determination of whether to operate the ultrasonic instrument 15 in the tissue resection mode or the tissue sense mode may be based on user settings input to the surgical system 10, such as via the control console 80. Additionally or alternatively, responsive to an initial actuation of the ultrasonic instrument 15, the process 700 may be configured to default to operating the ultrasonic instrument 15 in the tissue sense mode. Additionally or alternatively, the determination of which mode in which to operate the ultrasonic instrument 15 may be based on the tracked position of the distal region 84 of the tip 82 relative to the patient tissue, and / or based on a type of tissue previously detected to be in contact with the distal region 84 of the tip 82. For instance, response to the tracked position or previously detected type of tissueindicating contact with non-targeted tissue, the ultrasonic controller 150 may be configured to operate the ultrasonic instrument 15 in the tissue sense mode.

[0123] Responsive to determining to operate the ultrasonic instrument 15 in the tissue sense mode in block 708, the process 700 may proceed to block 710, in which the ultrasonic instrument 15 may be driven with a low power AC drive signal, which may induce vibrations in the tip 82 that are insufficient for resecting the patient tissue. As one example, and without limitation, the low power AC drive signal sourced in the tissue sense mode may be configured to induce a mechanical current iMin the ultrasonic instrument 15 of no more thanlO mA, or more particularly no more than 5 mA, or further more particularly no more than 2 mA, and / or induce vibrations at the distal region 84 of the tip 82 having an amplitude of no more than 30 microns, or more particularly no more than 10 microns, or further more particularly no more than 3 microns. In some implementations, irrigation and suction may be disabled during operation of the ultrasonic instrument 15 in the tissue sense mode, which may assist in improving the accuracy of the tissue sensing.

[0124] The optimal vibrations of the tip 82 for operation of the tissue sense mode may generally depend on the type of procedure and / or type of patient tissues involved in the procedure, and also the geometry, sharpness, and surface area of the tip 82. To this end, the read tissue sense data 191 may indicate varying sets of one or more drive signal parameters (e.g., target mechanical current iM, pulsing parameters, frequency) to use in the tissue sense mode for each of different sets of one or more tissue types and / or procedures, one of which may be selected by the operator via a user interface 28 and / or indicated in the surgical plan data 56. The ultrasonic controller 150 may thus be configured to utilize the set of one or more drive signal parameters associated with the indicated tissue type set and / or procedure to generate the AC drive signal sourced in the tissue sense mode.

[0125] At block 712, a voltage measurement and a current measurement of the sourced low-power AC drive signal may be obtained, such as using the voltage and current sensors described above. At block 714, a determination may be made of whether the ultrasonic instrument 15 is in a loaded or an unloaded state, such as based on a load measurement value determined for the ultrasonic instrument 15 based on one or more of the measurements. In some implementations, the voltage measurement may be used as the load measurement value. More specifically, when the vibrating tip 82 of the ultrasonicinstrument 15 is placed against tissue, such tissue may place a load on the tip 82 that dampens the vibrations, and correspondingly produces a mechanical impedance that reduces mechanical current iMbeing induced in the ultrasonic instrument 15. In response, the ultrasonic controller 150 may be configured to adjust the voltage of the AC drive signal so as to account for the increased mechanical impedance, and thereby maintain the induced mechanical current iMat the target level.

[0126] Correspondingly, a determination may be made of whether the ultrasonic instrument 18 is contacting tissue based on the obtained voltage measurement of the low power AC drive signal. Specifically, the obtained voltage measurement may be compared with a threshold voltage corresponding to contact of the distal region 84 of the tip 82 with tissue. In some implementations, this threshold may be ultrasonic instrument 15 specific, and may thus be included in the data read from the ultrasonic instrument 15, or more particularly from the tip memory 190. Responsive to the voltage measurement being greater than or equal to the voltage threshold, a determination may be made that the ultrasonic instrument 15 is in a loaded state. Otherwise, it may be determined that the ultrasonic instrument 15 is currently in an unloaded state.

[0127] As another example, the load measurement value may be calculated based on the obtained voltage measurement and the obtained current measurement. For instance, these measurements may be used to calculate the mechanical impedance ZMof the ultrasonic instrument 15, which may be substantially equal to the mechanical resistance RMof the ultrasonic instrument 15 when the ultrasonic instrument 15 is operating at resonance. Specifically, when the ultrasonic instrument 15 is operating at resonance, the inductive component LMand the capacitive component CMof the mechanical impedance ZMof the ultrasonic instrument 15 may cancel each other out, resulting in the mechanical impedance ZMof the ultrasonic instrument 15 being substantially equal to the mechanical resistance RMof the ultrasonic instrument 15. As the ultrasonic controller 150 is configured to set the frequency of the sourced AC drive signal so as to track resonance, the mechanical resistance RMof the ultrasonic instrument 15 may thus be calculated by calculating the mechanical current iMbeing induced in the ultrasonic instrument 15 based on the obtained current and voltage measurements as described above, and dividing the obtained voltage measurement by the determined mechanical current iMaccording to Ohm’s law. Thecalculated mechanical resistance RMmay then be compared with a resistance threshold (e.g., 2 kQ) corresponding to the contact of the distal region 84 of the tip 82 with tissue, which like the previous example may be indicated by the data read from the ultrasonic instrument 15. Responsive to the mechanical resistance RMbeing greater than or equal to the resistance threshold, a determination may be made that the ultrasonic instrument 15 is in a loaded state. Otherwise, it may be determined that the ultrasonic instrument 15 is currently in an unloaded state.

[0128] In some implementations, the load measurement value (e.g., voltage vs, mechanical resistance RM) may be compared to multiple thresholds, with one corresponding to the tip 82 being in contact with tissue (e.g., 2 KQ), and another corresponding to the tip 82 not being in contact with tissue (e.g., 600 Q). Responsive to the load measurement value being greater than or equal to the one threshold, a determination may be made that the ultrasonic instrument 15 is in the loaded state. Conversely, responsive to the load value being less than or equal to the other threshold, a determination may be made that the ultrasonic instrument 15 is in the unloaded state. Responsive to the load value being between the thresholds, the process 700 may be configured to return to block 710 and continue attempting to determine whether the ultrasonic instrument 15 is in the unloaded or loaded state as described above. In some implementations, the above thresholds may be tip 82 specific, and may thus be indicated in the data read from the tip memory 190 upon connection of the ultrasonic instrument 15.

[0129] Responsive to determining that the ultrasonic instrument 15 is in the unloaded state, the process 700 may proceed to block 716 to determine an unloaded resonant frequency of the ultrasonic instrument 18. As described above, the ultrasonic controller 150 may be configured to implement loops of tracking the resonant frequency of the ultrasonic instrument 15 based on a measured current and voltage of the AC drive signal, and setting the frequency of the AC drive signal based on the same. In the regular- course of tracking the resonant frequency as described above, the ultrasonic controller 150 may thus be configured to determine the resonant frequency of the ultrasonic instrument 18 based on the voltage and current measurements obtained in block 712. Responsive to determining that the ultrasonic instrument 15 is in the unloaded state based on these voltage and / or current measurements, the resonant frequency calculated from these measurements may beset as an unloaded resonant frequency of the ultrasonic instrument 15. Following determination of the unloaded resonant frequency, the process 700 may proceed back to blocks 712 and 714 to obtain additional voltage and current measurements and determine whether the tip 82 becomes loaded based on the same.

[0130] As described above, in some implementations, the unloaded resonant frequency may be indicated by and determined from the data read from the ultrasonic instrument 15 in block 702. In this case, block 716 may be omitted from the process 700. Alternatively, because the resonant frequency of the ultrasonic instrument 15 may fluctuate as a function of temperature, the process 700 may still include block 716, such as to verify or adjust the unloaded resonant frequency indicated by the read data as needed.

[0131] Responsive to determining that the ultrasonic instrument 15 is in a loaded state in block 714, the process 700 may proceed to block 718 to determine a loaded resonant frequency of the ultrasonic instrument 18, which as described above may have been calculated based on the current and voltage measurements obtained in block 712 to set the frequency of the sourced AC drive signal. Thereafter, the type of tissue being contacted by the distal region 84 of the tip 82 may be determined based on the loaded and unloaded resonant frequencies. Specifically, at block 718, a difference between the loaded and unloaded resonant frequencies may be calculated, and at block 720, a determination of the tissue type may be determined based on the difference.

[0132] More specifically, the difference may be queried against the tissue type data 172 stored in the console storage 152, which may indicate one or more thresholds each corresponding to a different type of tissue. In some implementations, the stored tissue type data 172 may correspond to the tissue type data 172A previously read from the ultrasonic instrument 15, and thus define at least one threshold specific to the tip 82.

[0133] In some examples, the tissue type data 172 may indicate a threshold for making a binary tissue type determination (e.g., hard vs soft tissue). For instance, the tissue type data 172 may indicate one threshold such that differences greater than or equal to the threshold indicate hard tissue, and differences less than or equal to the threshold indicate soft tissue.

[0134] In other examples, the tissue type data 172 may provide multiple thresholds for indicating contacted tissue types with increased granularity, such as very hard tissue (e.g.,enamel), hard tissue (e.g., bone), medium-hard tissue (e.g., skin, muscle tissue, organ tissue, and arteries), and soft tissue (e.g., fat). For example, the tissue type data 172 may indicate that a frequency difference greater than or equal to a first threshold (e.g., 350 Hz) corresponds to very hard tissue; a frequency difference greater than or equal to a second threshold (e.g., 175 Hz) and less than the first threshold corresponds to hard tissue; a frequency difference greater than or equal to a third threshold (e.g., 40 Hz) and less than the second threshold corresponds to medium hard tissue; and a frequency difference less than the third threshold corresponds to soft tissue.

[0135] In some examples and as described above, a determined loaded resonant frequency of the ultrasonic instrument 15 may be compared to a determined unloaded resonant frequency of the ultrasonic instrument 15 to determine the type of contacted patient tissue. In alternative implementations, rather than utilizing an unloaded resonant frequency of the ultrasonic instrument 15, which may vary as a function of temperature of the ultrasonic instrument 15, the process 700 may determine the type of contacted tissue based on a difference between two determined loaded resonant frequencies of the ultrasonic instrument 15, as described below.

[0136] To determine the type of contacted tissue based on the difference between two determined loaded resonant frequencies, the low power AC drive signal sourced to the ultrasonic instrument 15 in block 710 may be generated as a pulsed signal including a plurality of pulses each extending between an upper target amplitude (e.g., 8 mA) and a lower target amplitude (e.g., 3 mA). In some instances, the lower and upper target amplitudes for the AC drive signal may be indicated by the tissue sense data 191 read from the tip memory 190, and / or may correspond a user selection of a given tissue type or procedure, as described above. Assuming the low power AC drive signal is a pulsed signal, the load measurement utilized in block 714 to determine whether the ultrasonic instrument 18 is loaded may correspond to the upper amplitude portions of the AC drive signal. In other words, the load measurement value may be based on values of the obtained voltage measurement or of the obtained voltage and current measurements corresponding to the upper amplitude portion of each pulse.

[0137] Further in this case, block 718 of the process 700 may include determining multiple loaded resonant frequencies of the ultrasonic instrument 15 based on the obtained voltageand current measurements, namely, one corresponding to the upper amplitude of the AC drive signal, and another corresponding to the lower amplitude of the AC drive signal. In general, the effect on the resonant frequency of the ultrasonic instrument 15 by varying contacted tissues when the tip 82 is vibrating more slowly (i.e., at the lower amplitude of the AC drive signal) may be more similar' than when the tip 82 is vibrating more rapidly (i.e., at the higher amplitude of the AC drive signal). Specifically, when the tip 82 is rapidly vibrating against relatively harder tissues, the distal region 84 of the tip 82 may tend to bounce off the tissue throughout the vibrations, and when the tip 82 is rapidly vibrating against relatively softer tissues, the tissue may tend to move with the distal region 84 of the tip 82 throughout the vibrations. As a result, the difference between the resonant frequencies at the upper amplitude and the lower amplitude of the AC drive signal when the distal region 84 of the tip 82 is vibrating against hard tissue may be greater than when the distal region 84 of the tip 82 is vibrating against the soft tissue.

[0138] A difference may thus be calculated between these loaded resonant frequencies in block 720, and a type of contacted tissue may then be determined based on the frequency difference in block 722. More specifically, the difference may be queried against the tissue type data 172, which may indicate one or more thresholds for determining a tissue type as described above.

[0139] In some implementations, the ultrasonic controller 150 may be configured to utilize a determined unloaded resonant frequency as described above to determine a contacted tissue type upon initial activation of the ultrasonic instrument 15, such as for a set number of times, and thereafter utilize the difference between determined loaded resonant frequencies to determine the contacted tissue type. In some implementations, an event may trigger alternating between these unloaded and loaded methods. For instance, responsive to utilizing the unloaded method to determine a contacted tissue type for a set number of times, the ultrasonic controller 150 may be configured to implement the loaded method until it is detected that the ultrasonic instrument 15 is again in an unloaded state, in which case the ultrasonic instrument 15 may revert to the unloaded method for a set number of cycles, then proceed with the loaded method, and so on.

[0140] Still referring to FIG. 7, at block 724, operation of the surgical system 10 may be controlled based on the determined type of tissue. In some examples, block 724 mayinclude indicating the determined type of tissue to the operator, such as via one of the user interfaces 28 of the surgical system 10, or by inducing a specific pattern of vibratory pulses in the ultrasonic instrument 15 associated with the determined tissue type within the tissue type data 172. Additionally or alternatively, such as when the determined type of tissue corresponds to tissue targeted for resection, block 724 may include switching operation of the ultrasonic instrument 15 from the tissue sense mode to the tissue resection mode, discussed in greater detail below.

[0141] In some implementations, varying types of tissue, such as varying types of targeted tissue, may each be associated within the tissue type data 172 with a different ultrasonic energy profile to be induced in the ultrasonic instrument 15 when operating in the tissue resection mode responsive to the determined type of tissue corresponding to the given tissue type. The ultrasonic energy profiles may each define one or more parameters (e.g., target mechanical current iM, pulsing parameters) for the AC drive signal sourced to the ultrasonic instrument 15 in the tissue resection mode. For instance, relatively stiffer tissues, such as bone, may be associated with ultrasonic energy profiles for operating the ultrasonic instrument 15 at relatively high power levels, which may induce vibrations of greater amplitude and thus provide more resection power, than that of relatively softer tissues. Responsive to identifying contact with a tissue type targeted for resection, the ultrasonic controller 150 may thus be configured to automatically initiate operation of the ultrasonic instrument 15 in the tissue resection mode and according to the ultrasonic energy profile associated with the tissue type.

[0142] In some implementations, such as when the ultrasonic instrument 15 has been set to operate in the tissue resection mode to resect patient tissue, the ultrasonic controller 150 may be configured to periodically alternate operation of the ultrasonic instrument 15 between the tissue resection mode and the tissue sense mode, such as to check whether the tip 82 of the ultrasonic instrument 15 is contacting targeted or non-targeted tissue. Responsive to determining a targeted tissue type, block 724 may include returning operation to the tissue resection mode. Conversely, responsive to the determined tissue type indicating non-targeted tissue, block 724 may include deactivating the ultrasonic instrument 15 or continuing operation of the ultrasonic instrument 15 in the tissue sense mode until the detected tissue type corresponds to targeted tissue, and / or may includeproviding an indication that the distal region 84 of the tip 82 is contacting non-targeted tissue as described herein.

[0143] In some implementations, the determined type of tissue may indicate when the distal region 84 of the tip 82 has moved from an inner portion to an outer portion of an anatomical structure being resected. For instance, because bone stiffness decreases as it gets thinner, the determined tissue type may indicate when bone being resected is very thin and about to be broken through, which may not be desired, or may be desired without resecting sensitive structures or other non-targeted tissue adjacent the bone. Thus, responsive to the determined type of tissue indicating that the distal region 84 of the tip 82 has moved from an inner portion to an outer portion of a patient anatomy and is about to break through, block 724 may include executing a corresponding pre-breakthrough protocol, such as deactivating operation of the ultrasonic instrument 15, or operating the ultrasonic instrument in the tissue resection mode but with a reduced power level (e.g., lower target mechanical current iM, pulsed mode).

[0144] In some implementations, such as when the distal region 84 of the tip 82 is being tracked relative to a virtual object in a known coordinate system, block 724 may include adjusting a parameter such as a position, pose or shape of the virtual object in the known coordinate system based on the determined type of patient tissue. For instance, responsive to the determined type of tissue varying from an expected type of tissue based on the tracked position of the distal region 84 of the tip 82 relative to the virtual object, the virtual object may be adjusted so that the type of tissue indicated by the virtual object at the tracked position of the distal region 84 of the tip 82 corresponds to the determined type of tissue.

[0145] In some implementations, such adjusting may be based on multiple data points of determined types of tissue at different tracked positions of the distal region 84 of the tip 82 relative to the virtual object. For instance, responsive to a mismatch between the tissue type indicated by a tracked position of the distal region 84 of the tip 82 relative to a virtual boundary and the tissue type detected in the tissue sense mode (or the tissue resection mode, as described below), the navigation controller 24 and ultrasonic controller 150 may cooperate to operate the ultrasonic instrument 15 in the tissue sense mode, and to obtain a series of tracked positions of the distal region 84 of the tip 82 in the known coordinate system, along with a tissue type detected with the ultrasonic instrument 15 at each position.For instance, one of the navigation controller 24 or ultrasonic controller 150 may operate a user interface 28 to instruct the operator to trace the surrounding area with the ultrasonic instrument 15. The navigation controller 24 may then be configured to adjust the virtual object, such as according to constraints associated with the tracked object associated with the virtual object, so that the virtual object indicates, at each tracked position of the distal region 84 of the tip 82, the tissue type determined at the tracked position according to the tissue sense mode.

[0146] As previously described, the surgical system 10 may include a robotic manipulator 14 coupled to and configured to guide movement of the ultrasonic instrument 15 to treat the patient tissue, such as based on a tracked position of the distal region 84 of the tip 82 relative to a virtual object associated with patient tissue. In some implementations, block 724 may include controlling operation of the robotic manipulator 14 based on the determined tissue type, such as by adjusting the virtual object as described above, which may in turn alter the manner in which the robotic manipulator 14 guides movement of the ultrasonic instrument 15, such as to resect targeted patient tissue while avoided nontargeted patient tissue.

[0147] In some instances, at least one of the virtual objects for controlling operation of the robotic manipulator 14 may be a haptic object configured to cause the robotic manipulator 14 to apply forces on the movement of the ultrasonic instrument 15 that simulate an attraction or repulsion sensation, such as to guide the distal region 84 of the tip 82 to treat target tissue while avoiding contact with non-targeted tissue. In some implementations, block 724 may include adjusting a parameter of such virtual objects based on the determined tissue type by adjusting one or more of a position, pose, shape, or force associated with such objects. As an example, when the ultrasonic instrument 15 is being used to perform end plate preparation, a given haptic object may be configured to attract the distal region 84 of the tip 82 from a position within the intervertebral disc space towards the end plate so as facilitate the removal of cartilage from the end plate. However, once the determined tissue type indicates the distal region 84 of the tip 82 is contacting the end plate, the surgical navigation system 12 may be configured to adjust the haptic object so as to repel movement of the distal region 84 of the tip 82 away from the end plate, such as to avoid undesired resection thereof.

[0148] In some implementations, block 724 may include automatically initiating tracing of a patient anatomy upon detecting contact with a given type of tissue such as bone associated with the anatomy, which may be used to generate a virtual object corresponding to the anatomy, and subsequently to track a position of the distal region 84 of the tip 82 relative to the anatomy. Specifically, so long as the detected tissue type continues to correspond to the patient anatomy, the navigation controller 24 may be configured to track and store varying positions of the distal region 84 of the tip 82 relative to a known coordinate system, which may form a virtual model of the patient anatomy that is used by the navigation controller 24 as described above.

[0149] Still referring to FIG. 7, responsive to determining to operate the ultrasonic instrument 15 in the tissue resection mode in block 708, the process 700 may proceed to block 802 of the process 800, as illustrated in FIG. 8. In block 802, the ultrasonic instrument 15 may be driven with a high power AC drive signal that induces vibrations in the tip 82 of the ultrasonic instrument 15 for resecting patient tissue. The high power AC drive signal may be configured to drive the ultrasonic instrument 15 according to desired resection parameters set by the operator, such as a target ultrasonic energy level set via the foot pedal 138 and console settings as described above. For instance, the high power AC drive signal may be configured to induce a mechanical current iMof greater than 100 mA and / or induce vibrations having an amplitude of greater than 100 microns. Contemporaneously with driving the ultrasonic instrument with a high power AC drive signal, block 802 may also include supplying fluid to a distal region 84 of the tip 82 through at least a portion of the ultrasonic instrument 15, and / or providing suction at the distal region 84 of the tip 82 through at least a portion of the ultrasonic instrument 15, such as to irrigate and / or aspirate the fragmented tissue from the surgical site, respectively.

[0150] In some implementations, the tissue resection mode may also include a tissue sensing feature, which may be implemented simultaneously with the fragmentation of tissue. In other words, the tissue sensing feature of the tissue resection mode may be utilized during the sourcing of the high power AC drive signal to the ultrasonic instrument 15.

[0151] To this end, the process 800 may include blocks 804 and 806 of obtaining voltage and current measurements of the high power AC drive signal and determining whether theultrasonic instrument is in an unloaded state, respectively. The operations of blocks 804 and 806 may be similar to that described above relative blocks 712 and 714 of the process 700, and are thus not repeated in detail here. It is noted that responsive to determining that the ultrasonic instrument 15 is in an unloaded state in block 806, the process 800 may switch operation of the ultrasonic instrument 15 to the tissue sense mode, such as by proceeding to block 710 of FIG. 7.

[0152] In block 808, one or more frequency characteristics of the high power AC drive signal, each corresponding to a frequency or range of frequencies other than a fundamental drive frequency of the high power AC drive signal (e.g., the determined resonant frequency of the ultrasonic instrument 15), may be determined, such as based on the obtained current measurement. As an example, a Fourier transform may be applied to the obtained current measurement, and a magnitude characteristic of the Fourier transform for each of one or more frequency bins may be determined, each bin including a range of frequencies spaced from the fundamental driving frequency.

[0153] In some instances, each bin may correspond to or include a different harmonic of the fundamental drive frequency of the AC drive signal, and / or may be predefined in the tissue type data 172 or the tissue type data 172A read from the tip memory 190 of the ultrasonic instrument 15. For instance, the frequency bins may include one bin of frequencies spaced from the fundamental drive frequency by a predefined amount, and may include another bin of frequencies spaced from the fundamental drive frequency by double the predefined amount, or by the predefined amount and by an amount equal to the difference between the highest frequency and the lowest frequency of the other bin. In some instances, one of the bins may be centered on or include a first harmonic of the fundamental drive frequency, and another one of the bins may be centered on or include a second harmonic of the fundamental drive frequency. In some implementations, each bin may have a size of approximately 5 kHz, and / or the bins may be mutually exclusive. The magnitude characteristic of each bin may generally correspond to the magnitude of the frequencies of that bin. For instance, the magnitude of each bin may be determined as the peak magnitude of the bin, the integral of the magnitudes of the bin, or an average magnitude of the bin.

[0154] At block 812, a type of the patient tissue being contacted by the distal region 84 of the tip 82 may be determined based on the determined frequency charactcristic(s). More specifically, the tissue type data 172, which may be the tissue type data 172A previously read from the ultrasonic instrument 15, may indicate one or more thresholds corresponding to each determined frequency characteristic, such as in the form of one or more magnitude thresholds for each frequency bin, for determining contact with varying tissue types. Each determined frequency characteristic may thus be compared to the corresponding threshold(s) to determine the type of tissue.

[0155] In some examples, the tissue type data 172 may indicate a threshold for each frequency characteristic / bin for making a binary tissue type determination (e.g., hard vs soft tissue). For instance, the tissue type data 172 may indicate one threshold for each frequency characteristic / bin such that each frequency characteristic being greater than or equal to its corresponding threshold indicates contact with hard tissue, and otherwise indicates contact with soft tissue.

[0156] In other examples, the tissue type data 172 may provide multiple thresholds for each frequency characteristic / bin for indicating contacted tissue with increased granularity, such as very hard tissue, hard tissue, medium-hard tissue, and soft tissue. For example, the tissue type data 172 may indicate a first threshold for each frequency characteristic / bin such that each frequency characteristic being greater than its corresponding first threshold indicates contact with very hard tissue; may indicate a second threshold for each frequency characteristic / bin such that each frequency characteristic being greater than its corresponding second threshold and less than its corresponding first threshold indicates contact with hard tissue; may indicate a third threshold for each frequency characteristic / bin such that each frequency characteristic being greater than its corresponding third threshold and less than its corresponding second threshold indicates contact with medium-hard tissue; and each frequency characteristic being less than its corresponding third threshold indicates contact with soft tissue.

[0157] In some implementations, in instances where different frequency characteristics indicate different types of tissue based on a comparison with their corresponding thresholds, the tissue type may be determined to be the softest tissue indicated by the comparisons. Continuing with the above example, assuming two frequency characteristics,responsive to one frequency characteristic being greater than its corresponding first threshold, and the other frequency characteristic being greater than its second threshold but less than its first threshold, a determination may be made that the distal region 84 of the tip 82 is contacting hard tissue.

[0158] In some implementations, the tissue type data 172 may indicate multiple sets of thresholds each available for utilization as the above-described thresholds, and each corresponding to a different tissue type and / or procedure type selectable by the user. In some implementations, the determination of each frequency characteristic may be based on both the magnitude of the frequency bin corresponding to the characteristic, and also a corresponding magnitude of a frequency bin corresponding to the fundamental drive frequency of the sourced AC drive signal. For instance, the frequency characteristic for each frequency bin may be determined by subtracting the magnitude of the bin from the magnitude of a frequency bin corresponding to the fundamental frequency. In some implementations, rather than determining the frequency characteristics from a Fourier transform applied to an obtained current measurement of the AC drive signal, the frequency characteristics may be determined from a Fourier transform applied to a determined mechanical current iMof the ultrasonic instrument 15 induced as a result of the AC drive signal, which may be calculated based on the obtained current and voltage measurements as described above.

[0159] At block 812, operation of the surgical system 10 may be controlled based on the type of the patient tissue determined in block 810. As non-limiting examples, block 812 may include switching operation of the ultrasonic instrument 15 from the tissue resection mode to the tissue sense mode, such as responsive to determining contact with a nontargeted tissue type, a tissue type indicative of a breakthrough, and / or a tissue type indicative of a pre- breakthrough as described above. Additionally or alternatively, block 812 may include any one or more of the other actions discussed above relative to block 724. The process 800 may then proceed to block 706 of FIG. 7 to determine whether the ultrasonic instrument 15 continues to be actuated, and so on.

[0160] In some implementations, block 812 may also include regulating the suction provided at the distal region 84 of the tip 82 based on the type of tissue determined in block 810. Such suction may also be regulated based on the tissue type determined in block 722,such as when the ultrasonic instrument 15 is thereafter operated in the tissue resection mode. More specifically, the tissue type data 172 may indicate different suction parameters to be implemented by the ultrasonic controller 150 as a function of determined tissue type. For example, the tissue type data 172 may indicate a vacuum level to implement for each tissue type that is configured to improve resection and aspiration of the tissue type, and / or may indicate a clog threshold for each tissue type for determining whether the aspiration pathway is clogged with the tissue type. In regards to the latter, the ultrasonic controller 150 may be configured to measure a parameter of the suction provided at the distal region of the tip when operating in the tissue resection mode, such as using a pressure or flow sensor incorporated in the control console 80, and determine a blockage condition based on a comparison between the measured parameter and the clog threshold associated with the determined tissue type.

[0161] In some implementations, a given tip 82 may be operable in different vibratory modes (e.g., flexural, longitudinal, torsional-longitudinal, torsional). In this case, the ultrasonic controller 150 may be configured to induce different vibratory modes of the tip 82 for the tissue sense mode and the tissue resection mode. Specifically, each vibratory mode may be associated with a different drive signal frequency, and the ultrasonic controller 150 may be configured to induce a given vibratory mode of the tip 82 by sourcing the AC drive signal to the ultrasonic instrument 15 that includes a frequency component corresponding to the frequency of the vibratory mode. Examples of such tips 82 are described in U.S. Patent Nos. 10,786,275 and 10,561,435, the disclosures of each of which are hereby incorporated by reference herein in their entirety. In some implementations, the tissue sense data 191 read by the ultrasonic instrument 15 may indicate the vibratory mode to induce for each of the tissue resection mode and the tissue sense mode, such as by indicating the drive signal frequency associated with the mode.

[0162] For instance, a given tip 82 may have a longitudinal vibratory mode in which the vibrations at the distal region 84 of the tip 82 are substantially longitudinal, and a flexural vibratory mode in which the vibrations at the distal region 84 of the tip 82 are substantially flexural. In this case, the ultrasonic controller 150, such as based on the read tissue sense data 191, may be configured to induce the tip 82 to vibrate in the flexural vibratory mode when operating the ultrasonic instrument 15 in the tissue sense mode, such as by generatingand sourcing the low power AC drive signal with a frequency component corresponding to the frequency associated with the flexural vibratory mode, and to induce the tip 82 to vibrate in the longitudinal vibratory mode for the tissue resection mode, such as by generating and sourcing the high power AC drive signal with a frequency component corresponding to the resonant frequency associated with the longitudinal vibratory mode.

[0163] As a further example, a given tip 82 may have a first torsional-longitudinal vibratory mode in which the distal region 84 of the tip 82 rotates clockwise when vibrating in the proximal direction and counterclockwise when vibrating in the distal direction, and a second torsional-longitudinal vibratory mode in which the distal region 84 of the tip 82 rotates counterclockwise when vibrating in the proximal direction and clockwise when vibrating in the distal direction. The first torsional-longitudinal mode may be considered as causing torsional-longitudinal vibrations in an opposite direction than that of the second torsional-longitudinal mode. In this case, the ultrasonic controller 150, such as based on the read tissue sense data 191, may be configured to induce the tip 82 to vibrate in the first longitudinal-torsional mode when operating the ultrasonic instrument 15 in the tissue sense mode, such as by generating and sourcing the low power AC drive signal with a frequency component corresponding to the frequency associated with the first longitudinal-torsional mode, and to induce the tip 82 to vibrate in the second longitudinal-torsional mode for the tissue resection mode, such as by generating and sourcing the high power AC drive signal with a frequency component corresponding to the frequency associated with the second longitudinal-torsional mode.

[0164] Additionally or alternatively, in some implementations, such as when the frequency of the AC drive signal is being regulated to track the target vibratory characteristic of the ultrasonic instrument 15 such as resonance, the ultrasonic controller 150 may be configured to limit the frequency of the AC drive signal to different allowable frequency ranges depending on whether the ultrasonic instrument 15 is being operated in the tissue resection mode or the tissue sense mode. More specifically, when operating in the tissue resection mode, the ultrasonic controller 150 may be configured to limit the high power AC drive signal to an allowed frequency range associated with the tissue resection mode (e.g., 25kHz, +200Hz,-300Hz), and when operating in the tissue sense mode, limit the low power AC drive signal to an allowed frequency range associated with the tissue sense mode (e.g.,25kHz, ±2kHz). As shown in the above examples, the allowed frequency range associated with the tissue sense mode may be larger than the allowed frequency range associated with the tissue resection mode. In other words, a difference between the upper frequency and the lower frequency of the allowed frequency range associated with the tissue resection mode may be less than a difference between the upper frequency and the lower frequency of the allowed frequency range associated with the tissue sense mode. In this way, the ultrasonic controller 150 may be able to detect larger frequency jumps in the tissue sense mode while preventing the tip 82 from unintentionally exhibiting vibrations of an undesired vibratory mode in the tissue resection mode. In some implementations, the allowed frequency ranges for the tissue resection mode and the tissue sense mode may be indicated by the read tissue sense data 191.

[0165] The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Further, although each of the examples is described above as having certain features, any one or more of those features described with respect to any example of the disclosure can be implemented in and / or combined with features of any of the other examples, even if that combination is not explicitly described. In other words, the described examples are not mutually exclusive, and permutations of one or more examples with one another remain within the scope of this disclosure.

[0166] Spatial and functional relationships between elements (for example, between controllers, circuit elements, semiconductor layers, etc.) are described using various terms, including “connected,” “engaged,” “coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and “disposed.” Unless explicitly described as being “direct,” when a relationship between first and second elements is described in the above disclosure, that relationship can be a direct relationship where no other intervening elements are present between the first and second elements, but can also be an indirect relationship where one or moreintervening elements are present (either spatially or functionally) between the first and second elements.

[0167] As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.” The term subset does not necessarily require a proper subset. In other words, a first subset of a first set may be coextensive with (equal to) the first set.

[0168] In the FIGS., the direction of an arrow, as indicated by the arrowhead, generally demonstrates the flow of information (such as data or instructions) that is of interest to the illustration. For example, when element A and element B exchange a variety of information, but information transmitted from element A to element B is relevant to the illustration, the arrow may point from element A to element B. This unidirectional arrow does not imply that no other information is transmitted from element B to element A. Further, for information sent from element A to element B, element B may send requests for, or receipt acknowledgements of, the information to element A.

[0169] In this application, including the definitions below, the term “controller” or “module” may be replaced with the term “circuit.” The term “controller” may refer to, be part of, or include: at least one Application Specific Integrated Circuit (ASIC); at least one programmable system on a chip (PSoC); at least one digital, analog, or mixed anal og / digi tai discrete circuit; at least one digital, analog, or mixed analog / digital integrated circuit; at least one combinational logic circuit; at least one field programmable gate array (FPGA); at least one processor (shared, dedicated, or group) that executes code; at least one memory circuit (shared, dedicated, or group) that stores code executed by the at least one processor; other suitable hardware components that provide the described functionality; or a combination of some or all of the above, such as in a system-on-chip.

[0170] The controller may include one or more interface circuits with one or more transceivers, such as radio frequency (RF) or optical based transceivers (e.g. , infrared (IR)). In some examples, the interface circuit(s) may implement wired or wireless interfaces that connect to a local area network (LAN) or a wireless personal area network (WPAN). Examples of a LAN are Institute of Electrical and Electronics Engineers (IEEE) Standard 802.11-2016 (also known as the WIFI wireless networking standard) and IEEE Standard802.3-2015 (also known as the ETHERNET wired networking standard). Examples of a WPAN arc the BLUETOOTH wireless networking standard from the Bluetooth Special Interest Group and IEEE Standard 802.15.4.

[0171] The controller may communicate with other controllers using the interface circuit(s). Although the controller may be depicted in the present disclosure as logically communicating directly with other controllers, in various implementations the controller may actually communicate via a communications system. The communications system may include physical and / or virtual networking equipment such as hubs, switches, routers, gateways and transceivers. In some implementations, the communications system connects to or traverses a wide area network (WAN) such as the Internet. For example, the communications system may include multiple LANs connected to each other over the Internet or point-to-point leased lines using technologies including Multiprotocol Label Switching (MPLS) and virtual private networks (VPNs).

[0172] In various implementations, the functionality of the controller may be distributed among multiple controllers that are connected via the communications system. For example, multiple controllers may implement the same functionality distributed by a load balancing system. In a further example, the functionality of the controller may be split between a server (also known as remote, or cloud) controller and a client (or, user) controller.

[0173] Some or all hardware features of a controller may be defined using a language for hardware description, such as IEEE Standard 1364-2005 (commonly called “Verilog”) and IEEE Standard 1076-2008 (commonly called “VHDL”). The hardware description language may be used to manufacture and / or program a hardware circuit. In some implementations, some or all features of a controller may be defined by a language, such as IEEE 1666-2005 (commonly called “SystemC”), that encompasses both code, as described below, and hardware description.

[0174] The term code, as used above, may include software, firmware, and / or microcode, and may refer to programs, routines, functions, classes, data structures, and / or objects. The term shared processor circuit encompasses a single processor circuit that executes some or all code from multiple controllers. The term group processor circuit encompasses a processor circuit that, in combination with additional processor circuits, executes some orall code from one or more controllers. References to multiple processor circuits encompass multiple processor circuits on discrete dies, multiple processor circuits on a single die, multiple cores of a single processor circuit, multiple threads of a single processor circuit, or a combination of the above. The term shared memory circuit encompasses a single memory circuit that stores some or all code from multiple controllers. The term group memory circuit encompasses a memory circuit that, in combination with additional memories, stores some or all code from one or more controllers.

[0175] The term memory circuit is a subset of the term computer-readable medium. The term computer-readable medium, as used herein, does not encompass transitory electrical or electromagnetic signals propagating through a medium (such as on a carrier wave); the term computer-readable medium may therefore be considered tangible and non-transitory. Non-limiting examples of a non-transitory computer-readable medium are nonvolatile memory circuits (such as a flash memory circuit, an erasable programmable read-only memory circuit, or a mask read-only memory circuit), volatile memory circuits (such as a static random access memory circuit or a dynamic random access memory circuit), magnetic storage media (such as an analog or digital magnetic tape or a hard disk drive), and optical storage media (such as a CD, a DVD, or a Blu-ray Disc).

[0176] The apparatuses and methods described in this application may be partially or fully implemented by a special purpose computer created by configuring a general purpose computer to execute one or more particular functions embodied in computer programs. The functional blocks and flowchart elements described above may serve as software specifications, which can be translated into the computer programs by the routine work of a skilled technician or programmer.

[0177] The computer programs may include processor-executable instructions that are stored on at least one non-transitory computer-readable medium. The computer programs may also include or rely on stored data. The computer programs may encompass a basic input / output system (BIOS) that interacts with hardware of the special purpose computer, device drivers that interact with particular devices of the special purpose computer, one or more operating systems, user applications, background services, background applications, etc.

[0178] The computer programs may include: (i) descriptive text to be parsed, such as HTML (hypertext markup language), XML (extensible markup language), or JSON (JavaScript Object Notation), (ii) assembly code, (iii) object code generated from source code by a compiler, (iv) source code for execution by an interpreter, (v) source code for compilation and execution by a just-in-time compiler, etc. As examples only, source code may be written using syntax from languages including C, C++, C#, Objective C, Swift, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, JavaScript®, HTML5 (Hypertext Markup Language 5th revision), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, Visual Basic®, Lua, MATLAB, SIMULINK, and Python®.

Claims

CLAIMSWhat is claimed is:

1. A surgical system for detecting tissue types using an ultrasonic instrument for resecting patient tissue, the system comprising: a power supply configured to source varying AC drive signals to the ultrasonic instrument to induce varying vibrations in a tip of the ultrasonic instrument; at least one sensor for measuring at least one electrical characteristic of the AC drive signals; and one or more controllers coupled to the at least one sensor and the power supply and configured to: operate the ultrasonic instrument in a tissue resection mode in which a first AC drive signal is sourced to the ultrasonic instrument that induces vibrations in the tip of the ultrasonic instrument for resecting patient tissue; operate the ultrasonic instrument in a tissue sense mode in which a second AC drive signal is sourced to the ultrasonic instrument that induces vibrations in the tip for sensing patient tissue, the second AC drive signal being lower power than the first AC drive signal; obtain at least one measured first electrical characteristic of the second AC drive signal; determine a first frequency corresponding to a target vibratory characteristic of the ultrasonic instrument based on the at least one measured first electrical characteristic; determine a type of patient tissue being contacted by a distal region of the tip based on the determined first frequency; and control operation of the surgical system based on the determined type of patient tissue.

2. The system of claim 1, wherein the target vibratory characteristic is a resonant frequency of the ultrasonic instrument.

3. The system of claim 1 or 2, wherein the one or more controllers are configured to adjust a frequency characteristic of the second AC drive signal based on the determined first frequency.

4. The system of any one of claims 1-3, wherein the vibrations induced in the tip of the second AC drive signal are insufficient for resecting the patient tissue.

5. The system of any one of claims 1-4, wherein an amplitude of the vibrations induced in the tip of the ultrasonic instrument by the first AC drive signal is greater than an amplitude of the vibrations induced in the tip of the ultrasonic instrument by the second AC drive signal.

6. The system of any one of claims 1-5, wherein the at least one measured first electrical characteristic of the second AC drive signal comprises a first voltage measurement of the second AC drive signal and / or a first current measurement of the second AC drive signal.

7. The system of any one of claims 1-6, wherein the one or more controllers are configured to: read data from a memory of the ultrasonic instrument; and generate the second AC drive signal with electrical characteristics determined based on the read data.

8. The system of any one of claims 1-7, wherein the first AC drive signal includes a frequency characteristic corresponding to a first vibratory mode of the tip, and the second AC drive signal includes a frequency characteristic corresponding to a second vibratory mode of the tip.

9. The system of claim 8, wherein the first vibratory mode of the tip is a longitudinal vibration mode of the tip and the second vibratory mode of the tip is a flexural vibration mode of the tip.

10. The system of claim 8, wherein the first vibratory mode of the tip is a torsional-longitudinal vibration mode of the tip in a first direction, and the second vibration mode of the tip is a torsional- longitudinal vibration mode of the tip in a second direction opposite the first direction.11 . The system of any one of claims 1-10, wherein the one or more controllers are configured to: limit the first AC drive signal to a first allowed frequency range associated with the tissue resection mode, the first allowed frequency range defined by a first upper frequency and a first lower frequency; and limit the second AC drive signal to a second allowed frequency range associated with the tissue sensing mode, the second allowed frequency range defined by a second upper frequency and a second lower frequency, wherein a difference between the first upper frequency and the first lower frequency is less than a difference between the second upper frequency and the second lower frequency.

12. The system of any one of claims 1-11, wherein the one or more controllers are configured to: provide suction at the distal region of the tip through at least a portion of the ultrasonic instrument when operating in the tissue resection mode; and disable the provision of suction at the distal region of the tip through the at least a portion of the ultrasonic instrument when operating in the tissue sense mode.

13. The system of any one of claims 1-12, wherein the one or more controllers are configured to: determine that the distal region of the tip is in contact with the patient tissue based on the at least one measured first electrical characteristic; and determine the type of patient tissue being contacted by the distal region of the tip based on the determined first frequency responsive to determining that the distal region of the tip is in contact with the patient tissue.

14. The system of any one of claims 1-13, wherein the one or more controllers are configured to: determine a second frequency corresponding to the target vibratory characteristic of the ultrasonic instrument when operating in the tissue sense mode; and determine the type of patient tissue based on the determined first and second frequencies.

15. The system of claim 14, wherein the one or more controllers arc configured to determine the type of patient tissue based on a difference between the determined first frequency and the determined second frequency.

16. The system of claim 14 or 15, wherein the determined second frequency corresponds to an unloaded resonant frequency of the ultrasonic instrument.

17. The system of claim 16, wherein the one or more controllers are configured to read the second frequency from a memory included with the tip.

18. The system of any one of claims 14-16, wherein the one or more controllers are configured to: obtain at least one measured second electrical characteristic of the second AC drive signal; determine that the ultrasonic instrument is in an unloaded state based on the at least one measured second electrical characteristic; and responsive to determining that the ultrasonic instrument is in the unloaded state, determine as the second frequency a frequency corresponding to the target vibratory characteristic of the ultrasonic instrument and determined based on the at least one measured second electrical characteristic, wherein, optionally, the at least one measured second electrical characteristic comprises a measured voltage of the AC drive signal and / or a measured current of the AC drive signal.

19. The system of claim 14 or 15, wherein the second AC drive signal comprises a plurality of pulses each extending between an upper amplitude and a lower amplitude, the at least one measured first electrical characteristic each corresponds to the second AC drive signal at the upper amplitude, and the one or more controllers are configured to: obtain at least one measured electronic electrical characteristic of the second AC drive signal that each corresponds to the second AC drive signal at the lower amplitude; and determine the second frequency based on the at least one measured second electrical characteristic,wherein, optionally, the at least one measured second electrical characteristic comprises a second voltage measurement of the second AC drive signal and / or a second current measurement of the AC drive signal.

20. The system of any one of claims 1-19, wherein the one or more controllers are configured to switch operation of the ultrasonic instrument from the tissue sense mode to the tissue resection mode based on the determined type of patient tissue.

21. The system of any one of claims 1-20, wherein the one or more controllers are configured to periodically alternate operation of the ultrasonic instrument between the tissue resection mode and the tissue sense mode.

22. The system of any one of claims 1-21, wherein the one or more controllers are configured to: track a position of the distal region of the tip relative to a virtual object associated with the patient tissue in a known coordinate system; and adjust a pose of the virtual object in the known coordinate system based on the determined type of patient tissue.

23. The system of any one of claims 1-22, wherein the one or more controllers are configured to control a robotic manipulator to guide movement of the ultrasonic instrument to treat the patient tissue based on the determined type of patient tissue.

24. The system of claim 23, wherein the one or more controllers are configured to: control the robotic manipulator to guide the movement of the ultrasonic instrument to treat the patient tissue based on a virtual object associated with the patient tissue; and adjust a parameter of the virtual object based on the determined type of patient tissue.

25. The system claim 24, wherein the virtual object is a haptic object for controlling the robotic manipulator, and the one or more controllers are configured to adjust a position, pose, and / or force associated with the haptic object based on the determined type of patient tissue.

26. The system of any one of claims 1-25, wherein the one or more controllers arc configured to: determine that the distal region of the tip has moved from an inner portion to an outer portion of an anatomical object based on the determined type of patient tissue; and responsive to determining that the distal region of the tip has moved from an inner portion to an outer portion of the anatomical object, deactivate operation of the ultrasonic instrument or operate the ultrasonic instrument in the tissue resection mode with a reduced power level.

27. The system of any one of claims 1-26, wherein the one or more controllers are configured to: track a position of the distal region of the tip of the ultrasonic instrument in a known coordinate system; and generate a virtual model of an anatomical object in the known coordinate system based on the tracked position of the distal region of the tip and the determined type of patient tissue.

28. The system of any one of claims 27, wherein the one or more controllers are configured to:- determine that the distal region of the tip is contacting bone based on the first frequency; and generate a virtual model of the bone based on the tracked position of the distal region of the tip responsive to determining that the distal region of the tip is contacting bone.

29. The system of any one of claims 1-28, wherein the determined type of patient tissue is defined as a first determined type of patient tissue, and the one or more controllers are configured to: obtain at least one measured third electrical characteristic of the first AC drive signal when the ultrasonic instrument is operating in the tissue resection mode; determine one or more frequency characteristics of the first AC drive signal based on the at least one measured third electrical characteristic, each of the frequency characteristicscorresponding to a frequency of the first AC drive signal other than a fundamental frequency of the first AC drive signal; determine a type of patient tissue being contacted by the distal region of the tip based on the determined one or more frequency characteristics, the type of patient tissue determined based on the one or more frequency characteristics being defined as a second determined type of patient tissue; and controlling operation of the surgical system based on the second determined type of patient tissue, wherein, optionally, the at least one measured third electrical characteristic comprises a first voltage of the first AC drive signal and / or a first current of the first AC drive signal.

30. The system of claim 29, wherein the one or more frequency characteristics each comprises at least one characteristic of a frequency bin that does not include the fundamental frequency of the first AC drive signal.

31. The system of claim 29 or 30, wherein the one or more frequency characteristics each comprises at least one characteristic of a frequency bin that includes a harmonic frequency of the fundamental frequency of the first AC drive signal.

32. The system of any one of claims 29-31, wherein the one or more frequency characteristics comprises a plurality of frequency characteristics each comprising at least one characteristic of a different frequency bin that includes a different harmonic frequency of the fundamental frequency of the first AC drive signal, wherein, optionally, the frequency bins are mutually exclusive.

33. The system of any one of claims 29-32, wherein the one or more frequency characteristics each comprises a magnitude characteristic of the frequency bin.

34. The system of any one of claims 29-33, wherein the one or more controllers are configured to determine at least one phase characteristic of the first AC drive signal based on the at least one measured third electrical characteristic, wherein the second determined type of patient tissue isdetermined based on the one or more frequency characteristics and the at least one phase characteristic.

35. The system of any one of claims 29-34, wherein the one or more controllers are configured to: provide suction at the distal region of the tip through at least a portion of the ultrasonic instrument when operating in the tissue resection mode; and regulate the suction provided at the distal region of the tip when operating in the tissue resection mode based on at least one of the first determined type of patient tissue or the second determined type of patient tissue.

36. The system of any one of claims 29-35, wherein the one or more controllers are configured to: provide suction at the distal region of the tip through at least a portion of the ultrasonic instrument when operating in the tissue resection mode; measure a parameter of the suction provided at the distal region of the tip when operating in the tissue resection mode; and determine a blockage condition based on at least one of the first determined type of patient tissue or the second determined type of patient tissue and the measured parameter.

37. The system of claim 36, wherein the one or more controllers are configured to, responsive to determining the blockage condition, triggering an alert and / or disable a tissue detection functionality of the surgical system.

38. The system of any one of claims 29-37, wherein the one or more controllers are configured to switch operation of the ultrasonic instrument from the tissue resection mode to the tissue sense mode based on the second determined type of patient tissue.

39. The system of any one of claims 26-38, wherein the one or more controllers are configured to: obtain at least one measured fourth electrical characteristic of the first AC drive signal;determine that the ultrasonic instrument is in an unloaded state based on the at least one measured fourth electrical characteristic; and responsive to determining that the ultrasonic instrument is in the unloaded state based on the at least one measured fourth electrical characteristic, switch operation of the ultrasonic instrument from the tissue resection mode to the tissue sense mode, wherein, optionally, the at least one measured third electrical characteristic comprises a second voltage of the first AC drive signal and / or a second current of the first AC drive signal.

40. The system of any one of claims 29-39, wherein the one or more controllers are configured to: track a position of the distal region of the tip relative to a virtual object associated with an anatomical object in a known coordinate system; and adjust a pose of the virtual object in the known coordinate system based on second determined type of patient tissue.

41. The system of any one of claims 29-40, wherein the one or more controllers are configured to control a robotic manipulator to guide movement of the ultrasonic instrument to treat the patient tissue based the second determined type of patient tissue.

42. The system of claim 41, wherein the one or more controllers are configured to: control the robotic manipulator to guide the movement of the ultrasonic instrument to treat the patient tissue based on a virtual object associated with the patient tissue; and adjust a parameter of the virtual object based on the second determined type of patient tissue.

43. The system of claim 42, wherein the virtual object is a haptic object for controlling the robotic manipulator, and comprising adjusting a position, pose, and / or force associated with the haptic object based on the second determined type of patient tissue.

44. The system of any one of claims 29-43, wherein the one or more controllers are configured to:determine that the distal region of the tip has moved from an inner portion to an outer portion of an anatomical object based on the second determined type of patient tissue; and responsive to determining that the distal region of the tip has moved from an inner portion to an outer portion of the anatomical object, deactivate operation of the ultrasonic instrument, operate the ultrasonic instrument in the tissue resection mode with a reduced power level, or switch operation of the ultrasonic instrument to the tissue sense mode.

45. The system of any one of claims 29-44, wherein the one or more controllers are configured to: track a position of the distal region of the tip of the ultrasonic instrument in a known coordinate system; and generate a virtual model of a patient anatomy in the known coordinate system based on the tracked position of the distal region of the tip and the second determined type of patient tissue.

46. The system of claim 45, wherein the one or more controllers are configured to: determine that the distal region of the tip is contacting bone based on the one or more frequency characteristics; and generate a virtual model of the bone based on the tracked position of the distal region of the tip responsive to determining that the distal region of the tip is contacting bone.

47. A surgical system for detecting tissue types using an ultrasonic instrument for resecting patient tissue, the system comprising: a power supply configured to source varying AC drive signals to the ultrasonic instrument to induce varying vibrations in a tip of the ultrasonic instrument; at least one sensor for measuring at least one electrical characteristic of the AC drive signals; and one or more controllers coupled to the at least one sensor and the power supply and configured to: source an AC drive signal to the ultrasonic instrument that induces vibrations in the tip of the ultrasonic instrument for resecting patient tissue; obtain at least one measured first electrical characteristic of the AC drive signal;determine one or more frequency characteristics of the AC drive signal based on the at least one measured first electrical characteristic, each of the frequency characteristics corresponding to a frequency other than a fundamental frequency of the AC drive signal; determine a type of patient tissue being contacted by a distal region of the tip based on the determined one or more frequency characteristics; and control operation of the surgical system based on the determined type of patient tissue, wherein, optionally, each of the frequency characteristics comprises a characteristic of a frequency bin that does not include the fundamental frequency of the AC drive signal.

48. A surgical system for detecting tissue types using an ultrasonic instrument for resecting patient tissue, the system comprising: a power supply configured to source varying AC drive signals to the ultrasonic instrument to induce varying vibrations in a tip of the ultrasonic instrument; at least one sensor for measuring at least one electrical characteristic of the AC drive signals; and one or more controllers coupled to the at least one sensor and the power supply and configured to: source an AC drive signal to the ultrasonic instrument that induces vibrations in the tip that are insufficient for resecting the patient tissue; determine a first frequency corresponding to a target vibratory characteristic of the ultrasonic instrument when in an unloaded state; obtain at least one measured first electrical characteristic of the AC drive signal; determine a second frequency corresponding to the target vibratory characteristic of the ultrasonic instrument when in a loaded state; determine a type of the patient tissue being contacted by a distal region of the tip based on the first frequency and the second frequency; and control operation of the surgical system based on the determined type of patient tissue,wherein, optionally, the target vibratory characteristic is a resonant frequency of the ultrasonic instrument.

49. The system of claim 48, wherein the one or more controllers are configured to read the first frequency from a memory included with the tip.

50. The system of claim 48 or 49, wherein the one or more controllers are configured to: obtain at least one measured second electrical characteristic of the AC drive signal; determine that the ultrasonic instrument is in the unloaded state based on the at least one measured second electrical characteristic of the AC drive signal; and responsive to determining that the ultrasonic instrument is in the unloaded state, determine, as the first frequency, a frequency corresponding to the target vibratory characteristic of the ultrasonic instrument calculated based on the at least one measured second electrical characteristic of the AC drive signal.

51. The system of any one of claims 48-50, wherein the determined type of patient tissue is defined as a first determined type of patient tissue, and the one or more controllers are configured to: responsive to determining the type of patient tissue being contacted by the distal region of the tip based on the based on the first frequency and the second frequency, source a second AC drive signal to the ultrasonic instrument, the second AC drive signal being configured to induce vibrations in the distal region of the tip that are insufficient for resecting the patient tissue and comprising a plurality of pulses each extending between an upper amplitude and a lower amplitude; obtain at least one measured third electrical characteristic of the second AC drive signal that corresponds to the second AC drive signal at the upper amplitude; obtain at least one measured fourth electrical characteristic of the second AC drive signal that corresponds to the second AC drive signal at the lower amplitude; determine a third frequency associated with the upper amplitude and corresponding to the target vibratory characteristic of the ultrasonic instrument based on the at least one measured third electrical characteristic;determine a fourth frequency associated with the upper amplitude and corresponding to the target vibratory characteristic of the ultrasonic instrument based on the at least one measured fourth electrical characteristic; determine a type of patient tissue being contacted by the distal region of the tip based on the third frequency associated with the upper amplitude and the fourth frequency associated with the upper amplitude, the type of patient tissue determined based on the third and fourth frequencies being defined as a second determined type of patient tissue; and control operation of the surgical system based on the second determined type of patient tissue.

52. The system of claim 51, wherein the one or more controllers are configured to: obtain at least one measured fifth electrical characteristic of the second AC drive signal; determine that the distal region of the tip is in an unloaded state based on the at least one measured fifth electrical characteristic of the second AC drive signal; adjust the first frequency based on the at least one measured fifth electrical characteristic of the second AC drive signal; determine a type of patient tissue being contacted by the distal region of the tip based on the adjusted first frequency, the type of patient tissue determined based on the adjusted first frequency being defined as a third determined type of patient tissue; and control operation of the surgical system based on the second determined type of patient tissue, wherein, optionally, the at least one measured fifth electrical characteristic of the second AC drive signal corresponds to the second AC drive signal at the upper amplitude.

53. A surgical system for detecting tissue types using an ultrasonic instrument for resecting patient tissue, the system comprising: a power supply configured to source varying AC drive signals to the ultrasonic instrument to induce varying vibrations in a tip of the ultrasonic instrument; at least one sensor for measuring at least one electrical characteristic of the AC drive signals; andone or more controllers coupled to the at least one sensor and the power supply and configured to: operate the ultrasonic instrument in a tissue resection mode in which a first AC drive signal is sourced to the ultrasonic instrument that induces vibrations in the tip of the ultrasonic instrument for resecting patient tissue, wherein the first AC drive signal includes a frequency component corresponding to a first resonant mode of the tip; operate the ultrasonic instrument in a tissue sense mode in which a second AC drive signal is sourced to the ultrasonic instrument that induces vibrations in the tip that are insufficient for resecting the patient tissue, wherein the second AC drive signal includes a frequency component corresponding to a second resonant mode of the tip; obtain at least one measured first electrical characteristic of the second AC drive signal; determine a type of patient tissue being contacted by a distal region of the tip based on the at least one measured first electrical characteristic; and control operation of the surgical system based on the determined type of patient tissue.

54. A surgical system for detecting tissue types using an ultrasonic instrument for resecting patient tissue, the system comprising: a power supply configured to source varying AC drive signals to the ultrasonic instrument to induce varying vibrations in a tip of the ultrasonic instrument; at least one sensor for measuring at least one electrical characteristic of the AC drive signals; and one or more controllers coupled to the at least one sensor and the power supply and configured to: operate the ultrasonic instrument in a tissue resection mode in which a first AC drive signal is sourced to the ultrasonic instrument that induces vibrations in the tip of the ultrasonic instrument for resecting patient tissue, the first AC drive signal being limited to a first allowed frequency range associated with the tissue resection mode; operate the ultrasonic instrument in a tissue sense mode in which a second AC drive signal is sourced to the ultrasonic instrument that induces vibrations in the tip for sensingpatient tissue, the second AC drive signal being limited to a second allowed frequency range associated with the tissue sensing mode; obtain at least one measured first electrical characteristic of the second AC drive signal; determine a type of the patient tissue being contacted by a distal region of the tip based on the at least one measured first electrical characteristic; and control operation of the surgical system based on the determined type of patient tissue, wherein, optionally, the first allowed frequency range is defined by a first upper frequency and a first lower frequency, the second allowed frequency range defined by a second upper frequency and a second lower frequency, and a difference between the first upper frequency and first lower frequency is less than a difference between the second upper frequency and the second lower frequency.

55. A surgical system for detecting tissue types using an ultrasonic instrument for resecting patient tissue, the system comprising: a power supply configured to source varying AC drive signals to the ultrasonic instrument to induce varying vibrations in a tip of the ultrasonic instrument; at least one sensor for measuring at least one electrical characteristic of the AC drive signals; and one or more controllers coupled to the at least one sensor and the power supply and configured to: operate the ultrasonic instrument in a tissue resection mode in which a first AC drive signal is sourced to the ultrasonic instrument that induces vibrations in the tip of the ultrasonic instrument for resecting patient tissue and in which suction is provided at a distal region of the tip through at least a portion of the ultrasonic instrument; operate the ultrasonic instrument in a tissue sense mode in which a second AC drive signal is sourced to the ultrasonic instrument that induces vibrations in the tip for sensing patient tissue that are insufficient for resecting patient tissue and in which the suction provided at the distal region of the tip through the at least a portion of the ultrasonic instrument is disabled;obtain at least one measured first electrical characteristic of the second AC drive signal; determine a type of the patient tissue being contacted by the distal region of the tip based on the at least one measured first electrical characteristic; and control operation of the surgical system based on the determined type of patient tissue.

56. A surgical system for detecting tissue types using an ultrasonic instrument for resecting patient tissue, the system comprising: a power supply configured to source varying AC drive signals to the ultrasonic instrument to induce varying vibrations in a tip of the ultrasonic instrument; at least one sensor for measuring at least one electrical characteristic of the AC drive signals; and one or more controllers coupled to the at least one sensor and the power supply and configured to: operate the ultrasonic instrument in a tissue resection mode in which an AC drive signal is sourced to the ultrasonic instrument that induces vibrations in the tip of the ultrasonic instrument for resecting patient tissue and in which suction is provided at a distal region of the tip through at least a portion of the ultrasonic instrument; obtain at least one measured first electrical characteristic of the AC drive signal; determine a type of the patient tissue being contacted by the distal region of the tip based on the at least one measured first electrical characteristic; and regulate the suction provided at the distal region of the tip when operating in the tissue resection mode based on the determined type of patient tissue.

57. The system of claim 56, wherein the one or more controllers are configured to: measure a parameter of the suction provided at the distal region of the tip when operating in the tissue resection mode; and determine a blockage condition based on the determined type of patient tissue and the measured parameter.

58. The system of claim 57, wherein the one or more controllers are configured to, responsive to determining the blockage condition, trigger an alert and / or disable a tissue detection functionality of the surgical system.

59. The surgical system of any one of claims 1-59, comprising: a first tracker disposed relative to the patient tissue and a second tracker disposed relative to the ultrasonic instrument; and a localizer configured to generate data indicative of a pose of the first and second trackers in a known coordinate system, wherein the one or more controllers are configured to track a pose of the ultrasonic instrument relative to a virtual object associated with the patient tissue in the known coordinate system based on the localizer data.

60. The surgical system of any one of claims 1-60, comprising a robotic manipulator coupled to the ultrasonic instrument and configured to guide the ultrasonic instrument to treat the patient tissue.

61. The surgical system of any one of claims 1-61, comprising the ultrasonic instrument, the ultrasonic instrument including a driver coupled to the tip and configured upon application of an AC drive signal to vibrate the tip, and the tip defining a first pathway for providing the suction at the distal region of the tip and a second pathway for supplying irrigating fluid to the distal region of the tip.

62. A sleeve for an ultrasonic surgical tool including a tip and at least one driver to which the tip is coupled and to which an AC drive signal is sourced from a control console to vibrate the tip, the tip being operable in a tissue sense mode for sensing patient tissue and a tissue resection mode for resecting patient tissue, the sleeve comprising: a body including open proximal and distal ends and a conduit for flowing irrigating fluid down the sleeve and out the open distal end during operation of the ultrasonic surgical tool to vibrate the tip, the body adapted to be disposed around the tip and placed in an operative positionfor operating the ultrasonic surgical tool to vibrate the tip in which the tip extends from the open proximal end and out the open distal end; and a tip memory disposed in the body and storing data for controlling actuation of the tip in the tissue resection mode and in the tissue sense mode, wherein the data for controlling actuation of the tip indicates at least one of a drive signal frequency for the tissue sense mode, a drive signal frequency for the tissue resection mode that differs from the drive signal frequency for the tissue sense mode, an allowed drive signal frequency range for the tissue sense mode, an allowed drive signal frequency range for the tissue resection mode that differs from the allowed drive signal frequency range of the tissue sense mode, a drive signal frequency corresponding to a target vibratory characteristic of the ultrasonic surgical tool when in an unloaded state, data for identifying varying tissue types in contact with a distal region of the tip as a function of drive signal electrical characteristics, and suction parameters for varying tissue types.

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