Ultrasonic Surgical Systems

Abstract

The ultrasonic instrument includes a tip and a driver coupled to the tip, the driver configured to vibrate the tip to ablate tissue at the target site in response to receiving an AC drive signal from the power source. The localizer is configured to generate localization data indicative of a position of the ultrasonic instrument in a known coordinate system. A control system coupled to the power source and the localizer is configured to generate a virtual boundary associated with the tumor tissue region in the known coordinate system based on a received medical image including the tumor region, track a position of the ultrasonic instrument in the known coordinate system based on the localization data, and set the AC drive signal generated by the power source to induce a first pulsed ultrasonic energy in the tip based on the tracked position and virtual boundary of the ultrasonic instrument.

Description

[Technical field]

[0001] [Related Applications] This application claims priority to and the full benefit of U.S. Provisional Patent Application No. 63 / 362,598, filed April 6, 2022, U.S. Provisional Patent Application No. 63 / 362,599, filed April 6, 2022, and U.S. Provisional Patent Application No. 63 / 413,223, filed October 4, 2022. The disclosures of each of these applications are incorporated herein by reference in their entirety. [Background technology]

[0002] Ultrasonic surgical instruments are often used to remove tissue from sites with limited visibility, which can make it difficult for the surgeon to distinguish between tissue at the site targeted for removal and surrounding tissue that is desired to remain intact. Such limited visibility can also make it difficult to determine whether the targeted tissue has been removed in its entirety. Summary of the Invention

[0003] In one aspect, an ultrasonic surgical system includes an ultrasonic instrument having a tip and a driver coupled to the tip, the driver configured to vibrate the tip to cauterize tissue from a target site in response to receiving an AC drive signal, a power source coupled to the ultrasonic instrument and configured to generate the AC drive signal provided to the driver, a localizer configured to generate localization data indicative of a orientation of the ultrasonic instrument in a known coordinate system, and a control system coupled to the power source and the localizer, The control system is configured to receive medical images of the target site including a tumor tissue region, generate a virtual boundary associated with the tumor tissue region in the known coordinate system based on the medical images, track a orientation of the ultrasonic instrument in the known coordinate system based on the localization data, and set the AC drive signal generated by the power source to induce a first pulsed ultrasonic energy in the tip based on the tracked orientation and virtual boundary of the ultrasonic instrument.

[0004] In a further aspect, an ultrasonic surgical system includes an ultrasonic instrument having a tip and a driver coupled to the tip, the driver configured to vibrate the tip to ablate tissue from a target site in response to receiving an AC drive signal, a generator coupled to the ultrasonic instrument and configured to generate the AC drive signal provided to the driver, a localizer configured to generate localization data indicative of a position of the ultrasonic instrument in a known coordinate system, and a control system coupled to the generator and the localizer, The control system is configured to receive medical images of the target site including a first tissue region to be ablated, generate a virtual boundary associated with the first tissue region in the known coordinate system based on the medical images, track a position of the ultrasonic instrument in the known coordinate system based on the localization data, and set the AC drive signal generated by the generator to induce a first pulsed ultrasonic energy in the tip based on the tracked position of the ultrasonic instrument in the known coordinate system relative to the virtual boundary.

[0005] In a further aspect, an ultrasonic surgical system includes an ultrasonic instrument having a tip and a driver coupled to the tip, the driver configured to vibrate the tip to cauterize tissue from a target site in response to receiving an AC drive signal, a power source coupled to the ultrasonic instrument and configured to generate the AC drive signal provided to the driver, a localizer configured to generate localization data indicative of a position of the ultrasonic instrument in a known coordinate system, and a control system coupled to the power source and the localizer. The control system receives medical images of the target site including a soft tissue region and a hard tissue region, generates a virtual boundary between the soft and hard tissue regions in a known coordinate system based on the medical images, tracks a pose of the ultrasonic instrument in the known coordinate system based on the localization data, determines whether the ultrasonic instrument is within the hard or soft tissue region based on the tracked pose of the ultrasonic instrument in the known coordinate system relative to the virtual boundary, and in response to determining that the ultrasonic instrument is within the soft tissue region, generates a first AC drive signal to induce first pulsed ultrasonic energy in the ultrasonic instrument, where the first pulsed ultrasonic energy comprises a plurality of first ultrasonic energy pulses spaced apart by a first period of ultrasonic energy at a first minimum ultrasonic energy level. and in response to determining that the ultrasonic instrument is within the hard tissue region, generating a second AC drive signal to induce second pulsed ultrasonic energy in the ultrasonic instrument (wherein the second pulsed ultrasonic energy may include a plurality of second ultrasonic energy pulses spaced apart by a third period of ultrasonic energy at the second minimum ultrasonic energy level, each of the first ultrasonic energy pulses peaking at a maximum ultrasonic energy level set for the ultrasonic instrument for a second period that is shorter than each of the first periods).

[0006] In a further aspect, an ultrasonic surgical system includes an ultrasonic instrument having a tip and a driver coupled to the tip, the driver configured to vibrate the tip to cauterize tissue from a target site in response to receiving an AC drive signal, a power source coupled to the ultrasonic instrument and configured to generate an AC drive signal provided to the driver, a sample element coupled to the ultrasonic instrument and including at least one fiber configured to collect fluorescent light emitted from the tissue, and a control system coupled to the power source and the sample element, The control system is configured to detect a type of tissue being contacted by the tip of the ultrasonic instrument based on the fluorescence, and based on the detected tissue type, set the AC drive signal generated by the power source to induce a first pulsed ultrasonic energy in the tip.

[0007] In a further aspect, an ultrasonic surgical system includes an ultrasonic instrument having a tip and a driver coupled to the tip, the driver configured to vibrate the tip to ablate tissue from a target site in response to receiving an AC drive signal, a sample element coupled to the ultrasonic instrument and including at least one fiber configured to collect fluorescent light emitted from the tissue, and one or more controllers, the one or more controllers configured to determine a first tissue characteristic of the tissue contacted by the operative end of the tip as indicated by the collected fluorescent light, determine a characteristic of the AC drive signal delivered to the ultrasonic instrument corresponding to the collected fluorescent light indicative of the first tissue characteristic, determine a second tissue characteristic of the tissue contacted by the operative end of the tip as indicated by the characteristic of the AC drive signal, and display at least one indicator corresponding to the first tissue characteristic and the second tissue characteristic.

[0008] In a further aspect, an ultrasonic surgical system includes an ultrasonic instrument having a tip and a driver coupled to the tip, the driver configured to vibrate the tip to ablate tissue from a target site in response to receiving an AC drive signal, a sample element coupled to the ultrasonic instrument and including at least one fiber configured to collect fluorescent light emitted from the tissue, and one or more controllers, the one or more controllers configured to: determine a first tissue characteristic of tissue contacted by the operative end of the tip as indicated by the collected fluorescent light, determine a characteristic of the AC drive signal delivered to the ultrasonic instrument corresponding to the collected fluorescent light indicative of the first tissue characteristic, determine a second tissue characteristic of tissue contacted by the operative end of the tip as indicated by the characteristic of the AC drive signal, determine whether the first tissue characteristic is inconsistent with the second tissue characteristic, and indicate a system error in response to determining that the first tissue characteristic is inconsistent with the second tissue characteristic.

[0009] In a further aspect, an ultrasonic surgical system includes an ultrasonic instrument having an aspiration pathway, a tip, and a driver coupled to the tip, the driver configured to oscillate the tip to cauterize tissue from a target site in response to receiving an AC drive signal, a sample element coupled to the ultrasonic instrument and including at least one fiber configured to collect fluorescent light emitted from the tissue, one or more controllers, a sensor coupled to the aspiration pathway that measures properties of the ablated tissue moving through the aspiration pathway, and a control system configured to determine a first tissue property of the tissue contacted by the operative end of the tip as indicated by the collected fluorescent light, determine a second tissue property of the ablated tissue moving through the aspiration pathway as indicated by the sensor, determine an ablation status based on the first tissue property and the second tissue property, and display the ablation status. [Brief description of the drawings]

[0010] [Figure 1]FIG. 1 illustrates an ultrasonic surgical system incorporating a communicatively coupled ultrasonic tool system, a tissue detection system, a navigation system, and an imaging system. [Diagram 2] FIG. 1 illustrates a communicatively coupled ultrasound tool system and tissue detection system. [Diagram 3] FIG. 1 illustrates an ultrasonic instrument of an ultrasonic tool system. [Figure 4] FIG. 1 illustrates components that may be incorporated into a control console of an ultrasonic tool system. [Diagram 5] FIG. 1 illustrates components that may be incorporated into an ultrasonic instrument of an ultrasonic tool system. [Figure 6] FIG. 2 illustrates a circuit diagram representing current flow through an ultrasonic instrument of the ultrasonic tool system. [Figure 7] FIG. 1 illustrates a pulse profile that may be induced in an ultrasonic instrument of an ultrasonic tool system. [Figure 8] 13A-13C illustrate additional pulse profiles that may be induced within an ultrasonic instrument of an ultrasonic tool system. [Figure 9] 13A-13C illustrate additional pulse profiles that may be induced within an ultrasonic instrument of an ultrasonic tool system. [Figure 10] FIG. 13 illustrates a modulated waveform that may be generated by a control console of an ultrasonic tool system to direct pulsed ultrasonic energy within an ultrasonic instrument of the ultrasonic tool system. [Figure 11] FIG. 13 illustrates a base AC signal that may be generated by a control console of an ultrasonic tool system to direct pulsed ultrasonic energy within an ultrasonic instrument of the ultrasonic tool system. [Figure 12] FIG. 13 illustrates an AC signal that may be generated by a control console of an ultrasonic tool system to induce pulsed ultrasonic energy within an ultrasonic instrument of the ultrasonic tool system. [Figure 13] 1 illustrates a method of directing pulsed ultrasonic energy within an ultrasonic instrument. [Figure 14]1A-1C illustrate a method of providing tactile feedback to a practitioner operating an ultrasonic instrument by inducing pulsed ultrasonic energy within the ultrasonic instrument. [Figure 15] FIG. 13 illustrates a graph that may be used to provide tactile feedback to a practitioner operating an ultrasonic instrument by varying the pulse frequency of pulsed ultrasonic energy induced within the ultrasonic instrument as a function of applied load. [Figure 16] FIG. 13 is a graph illustrating providing tactile feedback to a practitioner operating an ultrasonic instrument by enabling and disabling pulsed ultrasonic energy within the ultrasonic instrument as a function of applied load. [Figure 17] FIG. 1 illustrates components that may be incorporated into a tissue detection system to detect characteristics of tissue contacted by an ultrasonic instrument. [Figure 18] FIG. 1 illustrates components that may be incorporated into a navigation system for tracking an ultrasonic instrument during a surgical procedure. [Figure 19] FIG. 1 illustrates a processing architecture that may be implemented by an ultrasonic surgical system. [Figure 20] 1 illustrates a method for operating an ultrasound instrument based on a tracked pose of the ultrasound instrument relative to a patient's anatomy. [Figure 21] 1A-1C illustrate virtual boundaries and regions that can be generated to control the operation of an ultrasonic instrument during a brain tumor resection procedure. [Figure 22] 1A-1C illustrate virtual boundaries and regions that can be generated to control the operation of an ultrasonic instrument during a spinal fixation procedure. [Diagram 23] 1 illustrates a method of operating an ultrasonic instrument based on tissue characteristics detected by a tissue detection system coupled to the ultrasonic instrument. [Figure 24] FIG. 1 illustrates a method for tissue detection that incorporates data from both an ultrasound tool system and a tissue detection system. [Diagram 25]FIG. 1 illustrates a graphical user interface (GUI) that may be used to show tissue characteristics detected by a communicatively coupled ultrasound tool system and tissue detection system. [Figure 26] FIG. 1 illustrates a method for tissue detection incorporating data from a communicatively coupled ultrasound tool system, a tissue detection system, and a navigation system. [Figure 27] FIG. 13 illustrates a GUI that may be used to show tissue characteristics detected by each of the communicatively coupled ultrasound tool system, tissue detection system, and navigation system. [Figure 28] 13A-13C illustrate a method for tracking the ablation status of a surgical procedure using data from an ultrasound tool system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] 1 illustrates an ultrasonic surgical system 10 that uses ultrasonic energy to ablate patient tissue during a surgical procedure while simultaneously detecting properties of contacted tissue and / or tracking the position of one or more objects to provide surgical guidance during the surgical procedure. The surgical system 10 may include an ultrasonic tool system 12, a tissue detection system 13, a navigation system 14, and an imaging system 15. As described in more detail below, the systems 12, 13, 14, 15 may be communicatively coupled to one another to facilitate features of the surgical system 10 described herein. In some embodiments, at least one of the tissue detection system 13, the navigation system 14, or the imaging system 15 may be omitted from the surgical system 10.

[0012] 2 and 3, the ultrasonic tool system 12 can include an ultrasonic control console 16 and an ultrasonic instrument 18. The ultrasonic instrument 18 can include a tip 20 having a tip head 22 (also referred to as a working end 22) configured to contact and treat patient tissue. In operation, the ultrasonic control console 16 can generate and provide an AC drive signal to the ultrasonic instrument 18, which induces ultrasonic energy in the ultrasonic instrument 18, causing the tip head 22 to rapidly vibrate. The practitioner can then position the vibrating tip head 22 against the patient tissue to cauterize the contacted tissue. The frequency, amplitude, and speed of vibration of the tip 20 can correspond to the frequency, amplitude, and speed of the induced ultrasonic energy, which can correspond to the frequency, amplitude, and speed of the AC drive signal.

[0013] The ultrasonic instrument 18 may include a hand piece 24 that is held by a practitioner to guide and manipulate the ultrasonic instrument 18 relative to patient tissue. The tip 20 may be removably coupled to the hand piece 24 to allow the hand piece 24 to be used with different interchangeable tips 20. Different tips 20 that are removably coupled to the hand piece 24 may be configured for different types of procedures. Some tips 20 that are removably coupled to the hand piece 24 may be configured to cauterize soft tissue, such as by inducing cavitation in the soft tissue. Tips 20 that are configured to cauterize soft tissue may define a lumen that provides suction through the tip 20 to the surgical site. Some tips 20 that are removably coupled to the hand piece may be configured to cauterize hard tissue, such as fibrous tissue and bone. Tips 20 that are configured to cauterize hard tissue may feature a tip head 22 formed with teeth or grooves that are sized to remove tissue via a cutting action. Tips 20 that are removably coupled to the hand piece 24 may also be of different lengths to provide access to the patient's anatomy at different depths. Some tips 20 removably coupleable to the hand piece 24 may be designed to oscillate only longitudinally at their tip heads 22, while other tips 20 removably coupleable to the hand piece 24 may be designed to oscillate both longitudinally and torsionally and / or substantially torsionally at their tip heads 22. As described in more detail below, the surgical system 10 may be configured to take into account a given tip 20 coupled to the hand piece 24 when detecting characteristics of tissue being contacted by the tip 20.

[0014] The handpiece 24 may form the proximal end of the ultrasonic instrument 18, and the tip 20 coupled to the handpiece 24 may form the distal end of the ultrasonic instrument 18. "Proximal" may be understood as toward the practitioner holding the ultrasonic instrument 18 and away from the tissue to which the tip 20 is being applied, and "distal" may be understood as away from the practitioner and toward the tissue to which the tip 20 of the ultrasonic instrument 18 is being applied.

[0015] The handpiece 24 may include a housing 26 that defines a handle by which the practitioner grasps and manipulates the ultrasonic instrument 18. The housing 26 may also define a cavity that houses the transducer 28. The transducer 28 may include one or more drivers 30, such as one or more piezoelectric crystals. The drivers 30 may be disk-shaped and may be arranged in an end-to-end stack within the housing 26. Each driver 30 may be formed from a material that undergoes instantaneous expansion and contraction along a longitudinal axis of the driver 30, i.e., an axis extending between a proximally directed face and a distally directed face of the driver 30, upon application of an alternating current. It is further contemplated that the drivers 30 may be realized as one or more magnetostrictive elements. An insulating disk may be disposed between adjacent drivers 30 and in tight abutment.

[0016] The transducer 28 may further include a tube 32 that may extend through the collinear longitudinal axis of the drivers 30 (and insulating disk, if present). To this end, each of the drivers 30 (and insulating disk) may include an internal through bore through which the tube 32 extends. The proximal end mass may be attached to a proximally-directed face of the proximal-most driver 30 and may be fixedly attached to the exposed proximal end section of the tube 32. In one example, the tube 32 may be threaded at least on the proximal end section, and the proximal end mass may be a nut threaded thereon.

[0017] The handpiece 24 may also include a horn 34 disposed at least partially within the cavity defined by the housing 26. The horn 34 may be coupled to a distal end of the transducer 28. The horn 34 may be constructed from a rigid steel alloy, titanium, or a similar material. During operation, the horn 34 may vibrate as the transducer 28 expands and contracts. The horn 34 may be removably coupled to the transducer 28. For example, the proximal end of the horn 34 may include a threaded male coupling and the distal end of the transducer 28 may include a corresponding female threaded coupling. Alternatively, the transducer 28 and the horn 34 may be permanently coupled via welding, adhesive, or a similar bonding process. The handpiece 24 may be configured such that the stack of the driver 30 is compressed between the proximal end mass and the horn 34.

[0018] The tip 20 can be removably coupleable to the horn 34. For example, the distal end of the horn 34 can include a threaded coupling configured to engage corresponding threads on the proximal end of the tip 20. It is further contemplated that other coupling methods can be utilized to removably couple the tip 20 to the horn 34. For example, the distal end of the horn 34 can include features that allow for a snap-fit ​​engagement with the tip 20.

[0019] The ultrasonic instrument 18 may be removably coupleable to the ultrasonic control console 16 via an electrical cable 36. One end of the electrical cable 36 may be permanently connected to the proximal end of the housing 26 of the ultrasonic instrument 18, and the other end of the electrical cable 36 may include an adapter 38 that corresponds to a socket 40 of the ultrasonic control console 16. The socket 40 may be shaped to receive the adapter 38 and may include electrical contacts that correspond to the electrical contacts of the adapter 38 such that when the adapter 38 is fully seated within the socket 40, an electrical connection is made between the ultrasonic instrument 18 and the ultrasonic control console 16.

[0020] When the ultrasonic instrument 18 is activated, the ultrasonic control console 16 may generate and deliver an AC drive signal to the ultrasonic instrument 18 via the electrical cable 36. Application of the AC drive signal to the ultrasonic instrument 18 may induce ultrasonic energy within the ultrasonic instrument 18, which may correspondingly cause the tip 20 of the ultrasonic instrument 18 to vibrate.

[0021] More specifically, the ultrasonic instrument 18 can be designed such that an AC drive signal from the ultrasonic control console 16 is applied in parallel to each of the drivers 30 of the transducers 28, thereby allowing the drivers 30 to simultaneously expand and contract along the longitudinal axis of the transducers 28 in accordance with the AC drive signal. The stack of drivers 30 may be 1 cm to 5 cm in length. The distance or amplitude of movement of the drivers 30 over a single expansion / contraction cycle can be from 0.01 microns to 10 microns.

[0022] The horn 34 can be configured to amplify this motion. As a result, the distal end of the horn 34, and thus the tip 20, can each move back and forth along its longitudinal axis between a fully retracted position and a fully extended position, thereby generating a longitudinal oscillatory motion. In some examples, the maximum peak-to-peak vibration of the tip head 22, representing a single movement from a fully retracted position to a fully extended position, can be 1000 microns, or 500 microns, or 300 microns. As previously mentioned, some tips 20 removably coupleable to the handpiece 24 can be configured to vibrate both longitudinally and torsionally and / or substantially torsionally at their tip head 22. Such tips 20 can include features along their length, such as helical grooves, configured to convert longitudinal vibrations applied to the proximal end of the tip 20 into vibrations at the tip head 22 having both longitudinal and torsional components and / or having substantially only a torsional component.

[0023] To assist in reducing heat generation during operation, the ultrasonic instrument 18 can define an irrigation pathway that provides irrigation fluid to a distal region of the tip 20 (e.g., tip head 22) and the surgical site. For example, the ultrasonic instrument 18 can include an irrigation sleeve 42 disposed about the tip 20 and adapted to be removably coupled to the handpiece 24, e.g., the housing 26 of the handpiece 24, to provide irrigation fluid to at least a distal region of the tip 20 and the surgical site.

[0024] The irrigation sleeve 42 can include a sleeve body 44 having an open proximal end and an open distal end and defining a lumen 46 extending between the open proximal end and the open distal end. The sleeve body 44 can be adapted to be coupled to the handpiece 24, such as the housing 26 of the handpiece 24, such that the tip 20 extends from the open distal end of the sleeve body 44 through the lumen 46. For example, the proximal end of the sleeve body 44 can be formed with a coupling mechanism that releasably couples the sleeve body 44 to the distal end of the housing 26. When positioned over the tip 20 and coupled to the housing 26, the sleeve body 44 can be radially spaced from the tip 20 and longitudinally spaced from the tip head 22 as described above. Components of the ultrasonic instrument 18 can be dimensioned such that the tip 20 does not contact the irrigation sleeve 42 during normal operation.

[0025] During operation of the ultrasonic instrument 18, irrigation fluid may flow from the hand piece 24 into the gap between the tip 20 and the sleeve body 44 and then out the open distal end of the sleeve body 44. More specifically, the hand piece 24 may include an irrigation conduit 48 that extends through the housing 26 from the proximal end to the distal end of the hand piece 24. The proximal end of the irrigation conduit 48 may be coupled to a fitting 50 of the ultrasonic instrument 18 that extends from the proximal end of the hand piece 24 to receive an irrigation line 52. The irrigation line 52 may be coupled to a fluid supply 54 via a cassette 56 that may be inserted into a corresponding slot 58 of the ultrasonic control console 16. During operation of the surgical system 10, a pump of the ultrasonic control console 16 may operate on the cassette 56 to draw fluid from the fluid supply 54 into the irrigation line 52 and thereafter into the irrigation conduit 48.

[0026] The irrigation sleeve 42 may likewise include an irrigation conduit 60 in fluid communication with the lumen 46 defined by the sleeve body 44. The irrigation conduit 60 may extend from a proximal region of the sleeve body 44 and extend to an opening 62 formed in a wall of the lumen 46 adjacent to the lumen 46. The opening 62 may be positioned in an intermediate portion of the lumen 46 between the proximal and distal ends of the lumen 46 and may be configured to supply irrigation fluid from the irrigation conduit 60 to a gap between the tip 20 and the sleeve body 44. The proximal end of the irrigation conduit 60 of the irrigation sleeve 42 may be adapted to fluidly engage with a distal end of the irrigation conduit 48 of the hand piece 24 when the irrigation sleeve 42 is coupled to the hand piece 24.

[0027] Thus, during operation of the ultrasonic instrument 18, irrigation fluid may flow from the fluid supply 54, through the irrigation line 52, the fitting 50, and the conduits 48, 60, out the opening 62 and into the lumen 46. Such irrigation fluid may then flow distally through the lumen 46 and out the open distal end of the sleeve body 44. In an alternative example, rather than being configured to receive irrigation fluid from the hand piece 24, the irrigation sleeve 42 may include a fitting disposed on the exterior surface of the sleeve body 44 for receiving the irrigation line 52 in fluid communication with the irrigation conduit 60 and passing outside of the hand piece 24. In this case, during operation of the ultrasonic instrument 18, irrigation fluid may similarly flow through the fitting, through the gap between the tip 20 and the sleeve body 44, and out the open distal end of the sleeve body 44.

[0028] The ultrasonic instrument 18 can also define an aspiration pathway that provides suction at a distal region of the tip 20 (e.g., the tip head 22). For example, the tube 32 of the transducer 28 can define a lumen extending from a proximal end to a distal end of the transducer 28 to form a fluid passageway therethrough. The horn 34 can similarly define a lumen extending from a proximal end to a distal end of the horn 34 to form a fluid passageway therethrough, and the tip 20 can also define a lumen extending from a proximal end to a distal end of the tip 20 to form a fluid passageway therethrough. Collectively, these lumens can form at least a portion of an aspiration pathway extending from a distal region of the tip 20 to a proximal region of the handpiece 24.

[0029] The ultrasonic instrument 18 may further include a fitting 64 coupled to the tube 32 and extending proximally from a proximal region of the hand piece 24 for receiving an aspiration line 66. During a procedure, suction may be applied to the fluid pathway defined by the tube 32, the horn 34, and the tip 20 via the fitting 64 and the aspiration line 66 to draw irrigation fluid applied to the surgical site and debris formed by the procedure entrained in the fluid toward and away from the proximal end of the hand piece 24. More specifically, the ultrasonic control console 16 may include a vacuum pump that is in fluid communication with a waste canister 70 via the cassette 56 when inserted into the ultrasonic control console 16, the waste canister 70 being separately disposed in fluid communication with the fluid pathway defined by the tube 32, the horn 34, and the tip 20, such as via the fluid pathway defined by the fitting 64, the aspiration line 66, and the cassette 56 when the cassette 56 is inserted into the ultrasonic control console 16. In this manner, the vacuum pump can apply suction to the fluid passageway defined by the tube 32, horn 34, and tip 20, through the waste canister 70, cassette 56, aspiration line 66, and fitting 64, thereby drawing material from the surgical site through said fluid passageway and into the waste canister 70. The suction can also function to draw tissue toward the tip head 22, which can improve the effectiveness of the tip 20 in treating patient tissue.

[0030] The ultrasonic tool system 12 may further include one or more sensors associated with the aspiration pathway to measure one or more characteristics of the ablated tissue traveling through the pathway. As described in more detail below, the surgical system 10 may be configured to use information generated by these sensor(s) to track the ablation status of the surgical procedure.

[0031] For example, a portion of the suction passage between the waste canister 70 and the ultrasonic instrument 18 may pass through a suction sensor 72 of the ultrasonic control console 16. The suction sensor 72 may be configured to generate data indicative of the presence and volume of patient tissue passing through the suction path. In some cases, the suction sensor 72 may include a flow sensor. Additionally or alternatively, the suction sensor 72 may include a scanner that scans the tissue passing through the suction path and generates corresponding data indicative of tissue characteristics, such as tissue size, volume, and / or type. For example, the scanner may include an IR transceiver and / or a fluorescent emitter / collector, such as similar to those described below, each of which may be configured to excite the ablated tissue passing through the suction path with light and then collect light signals emitted by the tissue as a result of the excitation to determine one or more of the tissue characteristics described above. In some cases, the target tissue may be stained to have distinctly different optical properties prior to the surgical procedure to enable the suction sensor 72 to distinguish ablated tissue corresponding to the target tissue from ablated tissue corresponding to non-target tissue. Additionally or alternatively, the sensor(s) associated with the suction pathway may include a weight sensor 73 configured to generate data indicative of the weight of patient tissue resected through the suction pathway and deposited in the waste canister 70.

[0032] The ultrasonic control console 16 may also include a display 74 that presents information to the practitioner. Non-limiting examples of the information presented may include the identity of the ultrasonic instrument 18, or more specifically the handpiece 24 and / or tip 20, currently connected to the ultrasonic control console 16, as well as the operational status of the ultrasonic tool system 12 and / or surgical system 10. The display 74 may be a touch screen display that allows the practitioner to provide input to the ultrasonic control console 16, such as via on-screen control elements. The practitioner may manipulate the on-screen control elements to set operational parameters of the ultrasonic tool system 12, such as maximum ultrasonic energy levels, suction levels, and irrigation levels of the ultrasonic instrument 18.

[0033] The ultrasonic tool system 12 may also include one or more actuation devices coupled to the ultrasonic control console 16. When activated by the practitioner, each of the actuation devices may cause the ultrasonic control console 16 to generate and deliver to the ultrasonic instrument 18 an AC drive signal that induces ultrasonic energy within the ultrasonic instrument 18 and correspondingly vibrates the tip 20 of the ultrasonic instrument 18 according to set operating parameters.

[0034] For example, the one or more actuation devices may include a foot pedal 76. The foot pedal 76 may be wirelessly connected to the ultrasonic control console 16, such as via an adapter 78 connected to the ultrasonic control console 16. When pressed, the foot pedal 76 may transition from an off position to an active position and, in response, may communicate an actuation signal to the ultrasonic control console 16 indicative of the press. In some examples, the communicated actuation signal may vary with the degree to which the foot pedal 76 is pressed, for example, allowing the practitioner to vary the ultrasonic energy level induced within the ultrasonic instrument 18, via the foot pedal 76, up to a set maximum ultrasonic energy level. In response to receiving the actuation signal, the ultrasonic control console 16 may generate and provide an AC drive signal to the ultrasonic instrument 18 that causes the tip 20 to vibrate according to the current settings of the ultrasonic control console 16 and / or the degree of press indicated by the actuation signal.

[0035] The ultrasonic tool system 12 may also include a remote control 80 coupled to the ultrasonic control console 16. Similar to the touch screen display 74, the remote control 80 may include practitioner selectable elements that provide input to the ultrasonic control console 16. For example, the remote control 80 may include buttons to set operating parameters of the ultrasonic tool system 12, such as maximum ultrasonic energy levels, suction levels, and irrigation levels of the ultrasonic instruments 18. The remote control 80 may also include a power button to turn the ultrasonic control console 16 on and off. Additionally or alternatively, the ultrasonic control console 16 may include an integral power button 82 to turn the ultrasonic control console 16 on and off.

[0036] 2 and 3, the tissue detection system 13 may be communicatively coupled to the ultrasonic tool system 12, such as via an electrical cable 84 connecting the ultrasonic control console 16 of the ultrasonic tool system 12 with a tissue detection control console 86 of the tissue detection system 13. The tissue detection system 13 may be configured to detect the type of tissue being contacted by the tip 20 of the ultrasonic instrument 18 and, in cooperation with the ultrasonic tool system 12, may be configured to control the operation of the surgical system 10, or more specifically, the ultrasonic instrument 18, based on the type of tissue detected.

[0037] The tissue detection system 13 may include a tissue detection control console 86 and a sample element 88. The sample element 88 may be connected to the tissue detection control console 86, such as via a connector 90 integral with the sample element 88 and inserted into a corresponding socket 92 of the tissue detection control console 86. The sample element 88 may be coupled to the ultrasonic instrument 18, such as along the length of the hand piece 24 and / or irrigation sleeve 42, as shown in the illustrated example. For example, but not limited to, the sample element 88 may be coupled to the ultrasonic instrument 18 using an adhesive, such as in the form of a pressure sensitive adhesive or glue, or via one or more fastening elements wrapped around the ultrasonic instrument 18 and the sample element 88, such fastening elements being spaced periodically along the length of the ultrasonic instrument 18.

[0038] The sample element 88 can include an excitation fiber 94 and can include a detection indicator 96. During a surgical procedure, the tissue detection control console 86 can be configured to illuminate tissue adjacent to or contacted by the operative end 22 of the tip 20 with excitation light via the excitation fiber 94. To this end, the excitation fiber 94 can span the length of the sample element 88 such that when the sample element 88 is coupled to the ultrasonic instrument 18, a distal region 98 of the excitation fiber 94 is adjacent to the operative end 22 of the tip 20 to enable excitation light to be delivered to tissue adjacent to or contacted by the operative end 22 of the tip 20. As shown in the illustrated example, the sample element 88 can be coupled to the ultrasonic instrument 18 in a manner such that there is no direct contact between the tip 20 and a distal portion of the sample element 88. For example, the sample element 88 can terminate adjacent to a portion of the irrigation sleeve 42 proximal to the operative end 22 of the tip 20. In another example, the sample element 88 may extend beyond the irrigation sleeve 42, but may be positioned such that there is sufficient empty space between the working end 22 of the tip 20 and the sample element 88 to prevent contact therebetween.

[0039] In response to being illuminated with excitation light at a given wavelength, different tissues may exhibit different levels and / or different wavelengths of fluorescence. For example, prior to a surgical procedure involving the removal of tumor tissue, aminolevulinic acid (5-ALA) may be administered to a patient several hours prior to surgery. 5-ALA is a naturally occurring compound in the hemoglobin synthesis pathway. In cancer cells, hemoglobin synthesis is disrupted and the pathway stops at an intermediate compound called Protoporphyrin IX (PPIX). When illuminated with a certain wavelength of excitation light (e.g., blue light) from the excitation fiber 94, tumor cells containing PPIX can absorb the excitation light and emit fluorescence with specific optical characteristics (e.g., red fluorescence at a minimal intensity level), thereby indicating the presence of tumor cells. As a further example, indocyanine green (ICG) may be administered to a patient prior to surgery, which can bind to plasma proteins found in the blood. When illuminated with excitation light of a certain wavelength (e.g., near-infrared light), ICG emits fluorescence with certain optimal characteristics (e.g., near-infrared fluorescence at a minimum intensity level), thereby indicating the presence of blood vessels. Other fluorescent dyes that can be excited to detect various types of tissue include hypericin and Hexvix®.

[0040] The tissue detection control console 86 may thus be configured to illuminate tissue adjacent to or in contact with the working end 22 of the tip 20 with excitation light at one or more wavelengths via the excitation fiber 94, and then collect emitted fluorescence from the illuminated tissue via the excitation fiber 94. In an alternative example, the tissue detection system 13 may include a separate fiber for collecting the emitted fluorescence, which may be incorporated into a separate collection element that extends along the sample element 88 and is connected to a socket 99 of the tissue detection control console 86. In either configuration, the tissue detection control console 86 may be configured to convert the collected light, such as via an integrated spectrometer, into an electrical signal that is interpreted by the tissue detection control console 86. The electrical signal may be indicative of the intensity of various fluorochromes contained in the collected light, and the tissue detection control console 86 may be configured to analyze the electrical signal to determine at least one characteristic of the tissue adjacent to or in contact with the working end 22 of the tip 20 of the ultrasonic instrument 18, as indicated by the electrical signal, such as tissue type. For example, the tissue detection control console 86 may be configured to compare the intensity of the red fluorescence indicated by the electrical signal to a minimum intensity threshold associated with tumor tissue. In response to the comparison indicating that the intensity of the red fluorescence is equal to or greater than the minimum intensity threshold, the tissue detection control console 86 may be configured to determine that the working end 22 of the tip 20 of the ultrasonic instrument 18 is currently in contact with tumor tissue. Otherwise, the tissue detection control console 86 may be configured to determine that the working end 22 of the tip 20 of the ultrasonic instrument 18 is currently in contact with non-tumor tissue.

[0041] In response to determining the presence of a tissue characteristic indicative of a given type of tissue, the tissue detection control console 86 can be configured to generate an activation signal that causes the detection indicator 96 to emit light, thereby providing the medical professional with a real-time indication of the presence of the given type of tissue. As shown in the illustrated example, the detection indicator 96 can be illuminated by an indicator fiber 100 that extends the length of the sample element 88 similar to the excitation fiber 94. The detection indicator 96 can be located proximal to a distal portion of the sample element 88 to ensure that the detection indicator 96 is visible to the practitioner as the practitioner is ablating the tissue. The detection indicator 96 can be transparent and can correspond to a removed portion of the jacket of the sample element 88. In one example, the sample element 88 can include a coaxial fiber with a central core and an outer channel covered by a jacket. The excitation fiber 94 can be disposed within the central core, while the indicator fiber 100 can be disposed within the outer channel. A portion of the jacket 102 of the sample element 88 can be removed to allow the indicator fiber 100 to shine light through the sidewall of the outer channel and illuminate the detection indicator 96 .

[0042] The indicator fiber 100 can be coupled to receive light from an excitation source integral with the tissue detection control console 86, the light being of a different wavelength than the excitation light used to illuminate the tissue. In response to detection of a tissue characteristic indicative of a given type of tissue, the tissue detection control console 86 can be configured to transmit light down the indicator fiber 100 to illuminate the detection indicator 96 via the excitation source of the tissue detection control console 86. In some examples, the detection indicator 96 can be illuminated with various colors of light depending on the tissue characteristic detected. For example, the tissue detection control console 86 can be configured to control the excitation source (e.g., one or more LEDs) to emit green light (e.g., wavelengths between about 520 nm and 564 nm) from the detection indicator 96 upon detection of PPIX fluorochrome above a threshold, and emit yellow light (e.g., wavelengths between about 565 nm and 590 nm) from the detection indicator 96 upon detection of ICG fluorochrome above a threshold.

[0043] The tissue detection control console 86 may also include a display 104 that presents information to the practitioner. One non-limiting example of the presented information may include an identification of a tissue characteristic detected by the tissue detection system 13. The display 104 may be a touch screen display that allows the practitioner to provide input to the tissue detection control console 86, such as via on-screen control elements. The practitioner may manipulate the on-screen control elements to set operating parameters of the tissue detection system 13, such as a tissue type targeted for ablation (e.g., tumor tissue) and / or characteristics of the tissue type targeted for ablation (e.g., the number and type of fluorochrome(s) corresponding to the tissue). In this manner, the tissue detection control console 86 may illuminate the detection indicator 96 in a particular manner in response to determining that the working end 22 of the tip 20 is in contact with or adjacent to tissue corresponding to the set tissue type and / or characteristics.

[0044] As mentioned above, the tissue detection system 13 can be in communication with the ultrasonic tool system 12. For example, such communication can be established through an electrical port 106 integral with the tissue detection control console 86, from which the electrical cable 84 can extend to a corresponding electrical port 107 on the ultrasonic control console 16. Alternatively, the communication link between the control consoles 16, 86 can be established wirelessly.

[0045] The tissue detection system 13 and the ultrasonic tool system 12 may be configured to cooperate to regulate the operation of the surgical system 10, or more specifically, the ultrasonic instrument 18. For example, similar to the tissue detection control console 86, the ultrasonic control console 16 may be configured to monitor one or more characteristics of the tissue contacted by the working end 22 of the tip 20. More specifically, characteristics of the AC drive signal provided to the ultrasonic instrument 18 to vibrate the tip 20 may be indicative of characteristics of the tissue contacted by the working end 22 of the tip 20, such as the mechanical impedance (e.g., stiffness) of the contacted tissue. Thus, the ultrasonic control console 16 may be configured to monitor one or more characteristics of the AC drive signal and determine at least one characteristic of the tissue contacted by the working end 22 of the tip 20 based on the one or more monitored characteristics. In addition to displaying at least one indicator corresponding to the tissue characteristics determined by the ultrasonic tool system 12 and the tissue detection system 13, such as on one or more of the displays 74, 104, the tissue detection system 13 and / or the ultrasonic tool system 12 may be configured to determine whether the tissue characteristics determined by the systems 12, 13 are inconsistent. If so, tissue detection system 13 and / or ultrasonic tool system 12 may be configured to trigger a system error, which may include preventing operation of ultrasonic instrument 18 until surgical system 10 is restarted via user input. These and other features of surgical system 10 are described in more detail below.

[0046] 4 illustrates components that may be integral to the ultrasonic control console 16. The control console 16 may include an ultrasonic controller 112, a signal generator 114, a transformer 116, and console storage 118. Generally, the signal generator 114 and the transformer 116 may form a power supply for the control console 16 configured to generate an AC drive signal that is supplied to the driver 30 of the ultrasonic instrument 18, with the output of these components regulated by the ultrasonic controller 112.

[0047] The ultrasonic controller 112 may include a processor 120 and a memory 122. The processor 120 may include one or more devices selected from a microprocessor, a microcontroller, a digital signal processor, a microcomputer, a central processing unit, a field programmable gate array, a programmable logic device, a state machine, a logic circuit, an analog circuit, a digital circuit, and / or any other device that manipulates signals (analog or digital) based on operational instructions that are read into the memory 122 and executed, such as from the console storage 118. The memory 122 may include a single memory device or multiple memory devices, including, but not limited to, read only memory (ROM), random access memory (RAM), volatile memory, non-volatile memory, static random access memory (SRAM), dynamic random access memory (DRAM), flash memory, cache memory, and / or any other device capable of storing information. The console storage 118 may include one or more persistent data storage devices, such as a hard drive, an optical drive, a tape drive, a non-volatile solid state device, and / or any other device capable of persistently storing information. Although shown separately from the ultrasound controller 112 in the illustrated example, the console storage 118 may additionally or alternatively be included in the ultrasound controller 112 , such as in communication with the processor 120 .

[0048] The ultrasound controller 112 may be configured to implement the functions, features, processes, and methods of the control console 16 described herein. More specifically, the processor 120 of the ultrasound controller 112 may operate under the control of a software program 123 embodied by computer-executable instructions, which may reside in the console storage 118 and be read into the memory 122 for execution by the processor 120. The computer-executable instructions may be compiled or interpreted from a variety of programming languages ​​and / or technologies, including, but not limited to, Java, C, C++, C#, Objective C, Fortran, Pascal, Java Script, Python, Perl, and PL / SQL, alone or in combination. The computer-executable instructions, when executed by the processor 120, may be configured to cause the processor 120 to implement the functions, features, processes, and methods of the control console 16 described herein. In this manner, the ultrasound controller 112, or more specifically the processor 120, may be configured to implement the functions, features, processes, and methods of the control console 16 described herein.

[0049] For example, the ultrasonic controller 112 may be configured, such as upon execution of the software program 123 by the processor 120, to control the level of ultrasonic energy induced within the ultrasonic instrument 18 by adjusting the AC drive signal provided to the ultrasonic instrument 18 from the control console 16, and to control the vibration of the tip 20 accordingly. More specifically, during operation of the ultrasonic tool system 12, the ultrasonic controller 112 may be configured to output one or more control signals to the signal generator 114 that correspond to a target AC drive signal provided to the ultrasonic instrument 18 from the control console 16. The signal generator 114 may be configured to responsively generate an AC signal across a primary winding 124 of the transformer 116, for example, using direct digital synthesis (DDS) and one or more amplifiers. The AC signal may be proportional to a target AC drive signal indicated by the one or more control signals, and thus may induce a target AC drive signal across a secondary winding 126 of the transformer 116, which may be coupled to the ultrasonic instrument 18 via electrical contacts 128, or the like.

[0050] 5, the electrical contacts 128 may be integrated with the socket 40 of the control console 16. Corresponding electrical contacts 130 may be integrated with the adapter 38 of the electrical cable 36. The electrical contacts 130 may also be electrically connected to opposing ends of each driver 30 of the ultrasonic instrument 18. When the adapter 38 is fully seated within the socket 40, the electrical contacts 128, 130 may align and form an electrical connection such that an AC drive signal generated across the secondary winding 126 of the transformer 116 may be applied to each driver 30 to induce ultrasonic energy within the ultrasonic instrument 18 and correspondingly cause vibration of the tip 20.

[0051] 6A and 6B show a circuit illustrating the current flow through the ultrasonic instrument 18 when an AC drive signal is applied to the ultrasonic instrument 18 from the control console 16. As shown in the illustrated example, the current i Sis a function of two components, i.e., the current i applied to the driver 30 of the ultrasonic instrument 18 O and the current i applied to the mechanical components of the ultrasonic instrument 18. M (hereinafter referred to as "machine current i M The mechanical components of the ultrasonic instrument 18 may include, but are not limited to, the driver 30, tube 32, horn 34, tip 20, and proximal mass described above, which vibrate in response to an applied AC drive signal to treat patient tissue.

[0052] The impedance Z presented by the driver 30 O can be primarily capacitive. Thus, the driver 30 has a capacitance C O The capacitance of the driver 30, C O may remain substantially constant during operation of the ultrasonic instrument 18 and thus may be determined and provided to the control console 16 prior to operation, such as upon connection of the ultrasonic instrument 18 to the control console 16, to tailor operation of the control console 16 to the particular handpiece 24 of the ultrasonic instrument 18. Additionally or alternatively, the control console 16 may determine the capacitance C of the driver 30 during operation of the ultrasonic instrument 18. O can be configured to measure periodically to allow for further accuracy.

[0053] The impedance Z provided by the mechanical components of the ultrasonic instrument 18 M (referred to herein as "mechanical impedance Z M ") can include inductive, resistive and capacitive components. Thus, the mechanical component is the inductance L M An inductor with resistor R M A resistor having a capacitance C M It can be equivalent to a capacitor having an inductance L M , resistance R M , and capacitance C M may vary with operation of the ultrasonic instrument 18 and may have at least a resistance RM (In this specification, "mechanical resistance R M ") can vary as a function of loads applied to the tip 20, such as by contacting patient tissue and / or irrigation fluid provided via the irrigation sleeve 42. In other words, the mechanical impedance Z M , or more specifically, the mechanical resistance R M may vary based on the hardness of the tissue to which the tip 20 is applied, and / or based on the force with which the practitioner applies the ultrasonic instrument 18 to the tissue, and / or based on the flow rate of irrigation fluid flowing through the sleeve 42.

[0054] The ultrasonic energy induced in the ultrasonic instrument 18, and the corresponding vibration of the tip 20, generates a mechanical current i M For example, the frequency of vibration in the tip head 22 can be proportional to the machine current i M , and when the ultrasonic instrument 18 is operating at resonance, the peak-to-peak displacement of the tip head 22 in microns corresponds to a machine current i in milliamps, depending on the gain of the tip 20. M As an example, a machine current i having an amplitude of 150 milliamps at the resonant frequency of the ultrasonic instrument 18 may be used. M can oscillate the tip head 22 of a given tip 20 back and forth along a path of travel of approximately 330 microns.

[0055] Thus, the ultrasonic controller 112 generates a machine current i having an amplitude corresponding to the target frequency and the target displacement level. M Vibrations in the tip 20 having a target frequency and a target displacement level can be induced by generating a control signal to the signal generator 114, which causes the signal generator 114 to provide an AC drive signal to the ultrasonic instrument 18 that induces a mechanical current i in the ultrasonic instrument 18. To this end, the ultrasonic controller 112 controls two control loops for inducing the target vibrations in the tip 20: M and a control loop that regulates the frequency of the mechanical current i induced in the ultrasonic instrument 18 by the AC drive signal.M The control loop may be configured to implement control loops that adjust the level or amplitude of each of the AC drive signals. Each control loop may incorporate a PID controller that effectively adjusts the AC drive signal to achieve a desired value and may have an iteration loop time of approximately 400 microseconds.

[0056] Using Ohm's law, the ultrasonic controller 112 determines the mechanical current i induced in the ultrasonic instrument 18 using the following equation: M It can be configured to calculate the level of i M =i S -j2πfC O v S (1) In the formula, i S is the current of the AC drive signal supplied to the ultrasonic instrument 18, f is the frequency of the AC drive signal, and C O is the capacitance of the driver 30, and v S is the voltage of the AC drive signal. An explanation of equation (1) is provided in commonly owned U.S. Patent No. 10,016,209, the contents of which are incorporated herein by reference in their entirety. Assuming that the frequency f of the AC drive signal has been pre-set to achieve a desired vibration characteristic (e.g., resonance) of the ultrasonic instrument 18, the ultrasonic controller 112 determines whether equation (1) satisfies the target level of machine current i M The voltage of the AC drive signal, v, is S By setting the target level of machine current i M , and correspondingly, a targeted vibration of the tip 20 can be induced.

[0057] As mentioned above, an integral property of the ultrasonic instrument 18 is the mechanical resonant frequency of the ultrasonic instrument 18. The mechanical resonant frequency is the frequency at which the distal end of the tip 20 undergoes a peak range of vibratory motion. In other words, assuming other electrical properties remain constant, at the resonant frequency the tip 20 undergoes motion that is greater in magnitude than motion that would occur if the driver 30 were vibrated at a frequency lower or higher than the resonant frequency. For a longitudinally vibrating tip 20, the peak range may be understood as the maximum front-to-back distance of the distal end of the tip 20.

[0058] The applicant's U.S. Patent No. 10,016,209 also discloses a means for tracking the resonant frequency of the ultrasonic instrument 18, which may vary during operation of the ultrasonic instrument 18. In particular, the ultrasonic instrument 18 is configured to generate a mechanical current i M The current through the driver 30 for i O A device may be considered to be operating at resonance when the real part of the ratio is substantially equal to zero. Thus, the ultrasonic controller 112 may be configured to determine the resonant frequency of the ultrasonic instrument 18 by determining the value of the frequency f of the AC drive signal such that the following equation holds: Re{(j2πfC O ) / (i S -j2πfC O )}~0 (2) In the formula, i S is the current of the AC drive signal supplied to the ultrasonic instrument 18, and C O is the capacitance of the driver 30. In response to determining the resonant frequency of the ultrasonic instrument 18, such as using equation (2), the ultrasonic controller 112 can be configured to set the frequency of the AC drive signal to the determined resonant frequency, thereby operating the ultrasonic instrument 18 at resonance.

[0059] The ultrasonic controller 112 may also be configured to track and set the frequency of the AC drive signal according to other vibration characteristics specific to the ultrasonic instrument 18, such as the anti-resonant frequency of the ultrasonic instrument 18. In this case, the ultrasonic controller 112 may be configured to determine the value of the frequency f such that the left side of equation (2) is substantially equal to 1.

[0060] When the frequency of the AC drive signal is adjusted to follow a target vibration characteristic of the ultrasonic instrument 18, such as resonance, a mechanical current i induced in the ultrasonic instrument 18 M Therefore, to direct targeted ultrasonic energy within the ultrasonic instrument 18, the ultrasonic controller 112 operates by adjusting the frequency of the AC drive signal based on equation (2) and the machine current i calculated according to equation (1). M corresponds to the target ultrasonic energy. S The operations of setting the metric may be configured to alternate in a repeatable manner or to be performed in parallel.

[0061] To this end, and referring again to FIGURE 4, the ultrasonic controller 112 may be configured to receive feedback data corresponding to the AC drive signal provided to the ultrasonic instrument 18, such as via one or more sensors integral to the control console 16. The ultrasonic controller 112 then determines the frequency and voltage v of the AC drive signal using equations (1) and (2), respectively. S Based on the received data, such as by providing the received data to a loop that regulates the ultrasonic energy in the ultrasonic instrument 18 and correspondingly induces targeted vibrations of the tip 20.

[0062] More specifically, the control console 16 controls the voltage v of the AC drive signal supplied to the ultrasonic instrument 18. S, which may include a regenerative coil 132 adjacent to or integrated with the transformer 116. The regenerative coil 132 may be connected to a voltage measurement circuit 134 in the control console 16, which may be connected to the ultrasonic controller 112. The signal across the regenerative coil 132 may be a signal that measures the voltage v of the AC drive signal supplied to the ultrasonic instrument 18. S Based on the signal across the regenerative coil 132, the voltage measurement circuit 134 measures the voltage v of the AC drive signal being supplied to the ultrasonic instrument 18. S , and communicates to the ultrasonic controller 112 a signal representative of the magnitude and phase of the AC drive signal v via the voltage measurement circuit 134 and the regenerative coil 132. S and generating a control signal that adjusts the AC drive signal based thereon.

[0063] The control console 16 also controls the current i of the AC drive signal provided to the ultrasonic instrument 18. S The ultrasonic instrument 18 may include a sensor that measures the current, i, of the AC drive signal provided to the ultrasonic instrument 18, which may include a coil 136 located proximate to one of the conductors extending from the secondary winding 126 of the transformer 116 to the ultrasonic instrument 18. The coil 136 may be connected to a current measurement circuit 138 of the control console 16, which may be connected to the ultrasonic controller 112. The signal across the coil 136 may represent the current, i, of the AC drive signal provided to the ultrasonic instrument 18. S Based on the signal across the coil 136, the current measurement circuit 138 measures the current i of the AC drive signal being supplied to the ultrasonic instrument 18. S , and communicates to the ultrasonic controller 112. Thus, the ultrasonic controller 112 can measure the current i of the AC drive signal via the current measurement circuit 138 and the coil 136. S and generating a control signal to adjust the AC drive signal based thereon.

[0064] In addition to the software programs 123 embodied by computer executable instructions, the console storage 118 may store data supporting the functions, features, processes, and methods of the control console 16 described herein. For example, the console storage 118 may include data defining one or more pulse profiles 140 for directing pulsed ultrasonic energy within the ultrasonic instrument 18, as described in more detail below, and may include tissue type data 142. The tissue type data 142, also described in more detail below, may associate different types of tissue with different characteristics of the ultrasonic instrument 18, or more specifically, different characteristics of the AC drive signal provided to the ultrasonic instrument 18 that are indicative of when the working end 22 of the ultrasonic instrument 18 is in contact with that type of tissue.

[0065] To effectively cauterize tissue, the ultrasonic control console 16, or more specifically, the ultrasonic controller 112, may vibrate the tip 20 of the ultrasonic instrument 18 at a relatively high rate. For example, at full power, the ultrasonic control console 12 may cause the tip 20 to vibrate at a frequency of 20 kHz to 40 kHz and a peak-to-peak displacement of approximately 300 microns. Vibrating the tip 20 at this rate may allow the ultrasonic instrument 18 to emulsify hard tissues such as fibrous tissue and bone, but maintaining this rate over the numerous vibration cycles that the tip 20 undergoes during operation may also generate a large amount of heat within the ultrasonic instrument 18 and at the surgical site. Such heat may affect the operation of the ultrasonic instrument 18 and increase trauma to surrounding tissue that is desired to remain intact.

[0066] However, when the tip 20 is vibrated at a constant rate to ablate hard tissue, each vibration cycle of the tip 20 may not cause an equal amount of ablation. Rather, multiple vibration cycles may simply increase heat generation at the surgical site without actually ablating any tissue. Thus, by periodically reducing the ultrasonic energy induced in the ultrasonic instrument 18, such as according to one of the predefined pulse profiles 140 stored by the ultrasound console storage 118, it may be possible to reduce heat generation while maintaining an effective ablation rate of hard tissue. In some examples, the pulse profile 140 may be similar to that described in applicant's PCT Publication No. 2022 / 072903, the contents of which are incorporated herein by reference in their entirety.

[0067] Each pulse profile 140 can define a pattern of ultrasonic energy induced within the ultrasonic instrument 18, the ultrasonic energy pattern including multiple ultrasonic energy pulses that peak at a maximum ultrasonic energy level set for the ultrasonic instrument 18 and are spaced apart by periods of ultrasonic energy at a minimum ultrasonic energy level set for the ultrasonic instrument 18. In some examples, the maximum ultrasonic energy level may be set by the practitioner and the minimum ultrasonic energy level can be defined by the pulse profile relative to the maximum ultrasonic energy level.

[0068] The ultrasonic energy induced into the ultrasonic instrument 18 can cause the tip 20 to vibrate at a frequency, amplitude, and velocity corresponding to the frequency, amplitude, and velocity of the induced ultrasonic energy, which can correspond to the frequency, amplitude, and velocity of the AC drive signal. For a given pulse profile 140, a peak vibration amplitude and velocity can occur in the tip 20 when a maximum ultrasonic energy level is induced into the ultrasonic instrument 18, which can be set at a level sufficient to ablate the target tissue of that type. Periodic reductions in the ultrasonic energy induced into the ultrasonic instrument 18 according to the pulse profile 140 can cause periodic reductions in the vibration amplitude and velocity of the tip 20 from the peak amplitude and velocity, thereby reducing heat generation within the ultrasonic instrument 18 and at the surgical site while maintaining an acceptable ablation rate. In other words, implementation of a given pulse profile 140 can reduce the number of vibration cycles that the tip 20 travels at peak speed for induction of ultrasonic energy within the ultrasonic instrument 18 that is maintained at a set maximum ultrasonic energy level, thereby reducing frictional heat generation.

[0069] In addition to reducing heat generation when cutting hard tissue, periodically reducing the ultrasonic energy induced within the ultrasonic instrument 18 according to the predetermined pulse profile 140 may allow for finer ablation control when applying the tip 20 to certain tissues, such as soft tissues, by causing oscillations of the tip 20 that slow the ablation rate of harder tissues while substantially maintaining the ablation rate of softer tissues. In other words, the predetermined pulse profile 140 may provide improved tissue selectivity.

[0070] Different pulse profiles 140 may be designed for different situations, such as targeting certain types of tissue for cauterization and / or providing the practitioner with increased tactile feedback when cutting hard tissue such as bone. In some examples, the practitioner may select a desired pulse profile 140 to operate the ultrasonic instrument 18, such as by manipulating the display 74 of the control console 16. In response to receiving a selection of a given pulse profile 140, the ultrasonic controller 112 may be configured to retrieve the pulse profile 140 from the console storage 118 and then generate and supply an AC drive signal to the ultrasonic instrument 18 in accordance with the retrieved pulse profile 140 that directs ultrasonic energy to the tip 20.

[0071] Each pulse profile 140 stored in the console storage 118 may be configured to induce ultrasonic energy including a series of ultrasonic energy pulses into the ultrasonic instrument 18. More specifically, each pulse profile 140 may indicate various target levels of ultrasonic energy to be induced into the ultrasonic instrument 18 as a function of time to form a series of ultrasonic energy pulses that peak at a maximum ultrasonic energy level determined for the ultrasonic instrument 18 and are spaced apart by ultrasonic energy at a minimum ultrasonic energy level determined for the ultrasonic instrument 18. For example, each pulse profile 140 may indicate various target levels of an upper envelope of the induced ultrasonic energy as a function of time or may indicate a target RMS value of the induced ultrasonic energy as a function of time. Thus, to implement a given pulse profile 140, the ultrasonic controller 112 may be configured to generate and supply to the ultrasonic instrument 18 AC drive signals that induce ultrasonic energy into the ultrasonic instrument 18 according to the various target levels indicated by the given pulse profile 140.

[0072] Each pulse profile 140 stored in the console storage 118 may include one or more pulse parameter settings that are specific to the pulse profile 140. The pulse parameter(s) may be used by the ultrasonic controller 112 to adjust the ultrasonic energy pulses directed into the ultrasonic instrument 18 and may include, for example, but not limited to, one or more of a coefficient that determines a minimum ultrasonic energy level of the directed pulsed ultrasonic energy, a pulse shape, a duty cycle, and a pulse frequency.

[0073] The minimum energy factor of each pulse profile 140 can define a minimum ultrasonic energy level of pulsed ultrasonic energy induced into the ultrasonic instrument 18 as a function of the maximum ultrasonic energy level set for the ultrasonic instrument 18. More specifically, each pulse profile 140 can be configured to induce ultrasonic energy into the ultrasonic instrument 18 including a series of ultrasonic energy pulses that peak at the maximum ultrasonic energy level set for the ultrasonic instrument 18 and are spaced apart by ultrasonic energy at the minimum ultrasonic energy level set for the ultrasonic instrument 18. The maximum ultrasonic energy level of each ultrasonic energy pulse can correspond to a maximum amplitude and velocity of vibration of the tip 20, and the minimum ultrasonic energy level can correspond to a minimum amplitude and velocity of vibration of the tip 20. The maximum ultrasonic energy level can be set by the practitioner, such as to a level sufficient to cauterize the target tissue, and the minimum ultrasonic energy level can be specific to the pulse profile 140 implemented. The minimum energy factor can indicate a percentage of the maximum ultrasonic energy level set for the ultrasonic instrument 18 to use as the minimum ultrasonic energy level, and can vary between pulse profiles 140. Thus, given a set maximum ultrasonic energy level, each pulse profile 140 can be configured to induce ultrasonic energy pulses within the ultrasonic instrument 18 that peak at the maximum ultrasonic energy level and are spaced apart by ultrasonic energy at different minimum ultrasonic energy levels specific to the pulse profile 140.

[0074] The pulse shape of each pulse profile 140 may define the shape of the dynamic portion (also referred to as the "transitional ultrasonic energy period") of each cycle of pulsed ultrasonic energy induced according to the pulse profile 140. Specifically, each ultrasonic energy pulse induced into the ultrasonic instrument 18 may be defined by a transition of ultrasonic energy from a minimum ultrasonic energy level set for the ultrasonic instrument 18 to a maximum ultrasonic energy level set for the ultrasonic instrument 18, and then a transition from the maximum ultrasonic energy level back to the minimum ultrasonic energy level. The period of each cycle of induced ultrasonic energy during which the ultrasonic energy is transitioning between the minimum ultrasonic energy level and the maximum ultrasonic energy level may be referred to as the dynamic portion of the cycle and may be defined by the pulse shape of the currently selected pulse profile 140. In other words, rather than the transition between the maximum ultrasonic energy level and the minimum ultrasonic energy level being arbitrarily shaped by the inherent electrical characteristics of the ultrasonic tool system 12, such transition may be specifically controlled to follow a predetermined transition function corresponding to the pulse shape of the applied pulse profile 140. As examples, the pulse shape of a given pulse profile 140 may be a Hann shape corresponding to a Hann wave transition function, a square shape corresponding to a square wave transition function, a triangular shape corresponding to a triangle wave transition function, a ramp-up sawtooth shape corresponding to a ramp-up sawtooth wave transition function, a ramp-down sawtooth shape corresponding to a ramp-down sawtooth transition function, or an inverse version of any of these pulse shapes.

[0075] The duty cycle of each pulse profile 140 may indicate the duration of the dynamic portion of the cycle relative to the total duration of the cycle for each cycle of pulsed ultrasonic energy induced in the ultrasonic instrument 18 according to the pulse profile 140. For a pulse profile 140 having a 100% duty cycle, the dynamic portion of each cycle of induced ultrasonic energy may span the entire duration of the cycle. In this case, the ultrasonic energy level induced by the pulse profile 140 may be considered to be constantly transitioning. In other words, the ultrasonic energy induced by the pulse profile 140 having a 100% duty cycle may reach a maximum ultrasonic energy level and a minimum ultrasonic energy level in a fraction of a second (e.g., less than 1 millisecond) before transitioning to the other of the maximum ultrasonic energy level and the minimum ultrasonic energy level according to the pulse shape of the pulse profile 140, etc. Conversely, for a pulse profile 140 associated with a duty cycle less than 100%, the duration of the dynamic portion of each cycle of induced ultrasonic energy may be a fraction of the total cycle duration corresponding to the duty cycle. The remaining portion of each cycle, referred to as the constant portion of the cycle, may be occupied by a period of ultrasonic energy maintained at a constant level, such as a maximum ultrasonic energy level or a minimum ultrasonic energy level.

[0076] The pulse frequency of each pulse profile 140 may indicate the frequency of the ultrasonic energy pulses that are induced into the ultrasonic instrument 18. Although the resonant frequency of the ultrasonic instrument 18 may be between 10 kHz and 40 kHz, the pulse frequency may be much lower, such as below 100 Hz. For example, a pulse frequency of 50 Hz for a given pulse profile 140 serves to induce ultrasonic energy into the ultrasonic instrument 18 that includes ultrasonic energy pulses that occur every 20 milliseconds.

[0077] As previously discussed, the ultrasonic energy induced within the ultrasonic instrument 18, and the corresponding vibration of the tip 20 of the ultrasonic instrument 18, generates a mechanical current i induced within the ultrasonic instrument 18. M Thus, each pulse profile 140 may be proportional to the ultrasonic energy induced in the ultrasonic instrument 18, or the mechanical current i induced in the ultrasonic instrument 18. M In other words, the maximum ultrasonic energy level set for the ultrasonic instrument 18 may be defined with reference to the corresponding maximum machine current i set for the ultrasonic instrument 18. M and the minimum ultrasonic energy level set for the ultrasonic instrument 18 can be expressed as a corresponding minimum machine current i set for the ultrasonic instrument 18. M It can be expressed as:

[0078] In some implementations, the control console 16 can be configured to operate the ultrasonic instrument 18 in multiple ablation modes, such as a soft tissue ablation mode for ablating soft tissue and a hard tissue ablation mode for ablating hard tissue, such as fibrous tissue and bone, in which case the console storage 118 can be configured to store one or more separate pulse profiles 140 for each mode, with the pulse parameters of each pulse profile 140 including a parameter indicating whether the pulse profile 140 is associated with a soft tissue ablation mode or a hard tissue ablation mode.

[0079] 7(A) illustrates a pulse pattern of a soft tissue pulse profile 144 that may be stored by the control console 16 in association with a soft tissue ablation mode, and FIG. 7(B) illustrates a pulse pattern of a hard tissue pulse profile 146 that may be stored by the control console 16 in association with a hard tissue ablation mode. In other words, in response to determining that the ultrasonic instrument 18 is configured to operate in a soft tissue ablation mode, the control console 16 may be configured to make the soft tissue pulse profile 144 available for user selection, and in response to determining that the ultrasonic instrument 18 is configured to operate in a hard tissue ablation mode, the control console 16 may be configured to make the hard tissue pulse profile 146 available for user selection. The control console 16 may be configured to determine whether the ultrasonic tool system 12 is configured to operate in a soft tissue ablation mode or a hard tissue ablation mode in response to a corresponding user input and / or based on data retrieved from the ultrasonic instrument 18, as described in more detail below.

[0080] Each of Figures 7(A) and (B) also illustrates a constant energy profile 148 that may be induced within the ultrasonic instrument 18 when the pulse mode is disabled by the practitioner via the display 74 of the control console 16, or when the control console 16 determines that the tip 20 currently coupled to the control console 16 is not capable of being pulsed.

[0081] 7(A) and (B) may be configured to induce ultrasonic energy into the ultrasonic instrument 18 that is maintained at a constant ultrasonic energy level, such as a maximum ultrasonic energy level set for the ultrasonic instrument 18. In other words, when the constant energy profile 148 is applied, the ultrasonic controller 112 controls the mechanical current i induced in the ultrasonic instrument 18 at a constant level, such as a constant level corresponding to the maximum ultrasonic energy level set for the ultrasonic instrument 18. MThe ultrasonic instrument 18 may be configured to generate and supply an AC drive signal that maintains

[0082] The maximum ultrasonic energy level of the ultrasonic instrument 18 may be set based on a power setting selected by the practitioner, which represents a percentage of the overall ultrasonic energy limit of the ultrasonic instrument 18. The maximum ultrasonic energy level may further be adjusted downward from the ultrasonic energy level indicated by the practitioner selected power setting as a function of the position of the foot pedal 76. Specifically, the control console 16 may be configured to linearly increase the maximum ultrasonic energy level from a minimum value (e.g., zero) to the level indicated by the practitioner selected power setting as the foot pedal 76 moves from a fully undepressed position to a fully depressed position. Thus, the maximum ultrasonic energy level set for the ultrasonic instrument 18 may vary during a treatment as a function of changes to the practitioner's power setting selection and / or foot pedal 76 depression level.

[0083] 7A and 7B may correspond to a set maximum ultrasonic energy level. As discussed above, continued operation of the ultrasonic instrument 18 at the maximum ultrasonic energy level may cause undesirable heating of the ultrasonic instrument 18 and the surgical site, and may increase potential trauma to surrounding tissue that is desired to remain intact.

[0084] Referring to FIG. 7(A), each of the soft tissue pulse profiles 144 can be configured to induce ultrasonic energy within the ultrasonic instrument 18 including multiple ultrasonic energy pulses spaced by periods of ultrasonic energy at a minimum ultrasonic energy level of the ultrasonic instrument 18 determined in accordance with the soft tissue pulse profile 144, each of the ultrasonic energy pulses being defined by a Hann wave and peaking at a maximum ultrasonic energy level.

[0085] The dynamic period of the pulsed ultrasonic energy induced by each soft tissue pulse profile 144 may correspond to the period during which the induced ultrasonic energy transitions from a minimum ultrasonic energy level set according to the soft tissue pulse profile 144 to a maximum ultrasonic energy level and then back to the minimum ultrasonic energy level. In other words, the dynamic portion of the soft tissue pulse profile 144 may correspond to the ultrasonic energy pulses of the induced ultrasonic energy. Thus, the pulse shape parameters for each of the soft tissue pulse profiles 144 shown in FIG. 7(A), which define the shape of the dynamic portion of the ultrasonic energy induced by the soft tissue pulse profile 144, may be set to a Hann pulse shape.

[0086] As shown in the illustrated example, soft tissue pulse profile 144A may have a 100% duty cycle, and thus the dynamic portion of each cycle of ultrasonic energy induced according to soft tissue pulse profile 144A may span the entire cycle. Conversely, soft tissue pulse profiles 144B-144E may each have a duty cycle less than 100%. Thus, the dynamic portion of each cycle of ultrasonic energy induced according to soft tissue pulse profiles 144B-144E may span only a portion of the cycle, with the remainder of the cycle being a constant ultrasonic energy portion in which ultrasonic energy is maintained at a minimum ultrasonic energy level for a significant period of time. The duration of the constant ultrasonic energy portion may vary depending on the selected soft tissue pulse profile 144. For example, the duration may be 2 milliseconds or more for some soft tissue pulse profiles 144 and 5 milliseconds or more for others.

[0087] As an example, the duty cycle associated with soft tissue pulse profile 144B may be 90%. Assuming each soft tissue pulse profile 144 has a pulse frequency of 50 Hz as shown in FIG. 7(A), soft tissue pulse profile 144B may thus be configured to induce ultrasonic energy pulses each 18 milliseconds in duration and spaced apart by periods of constant ultrasonic energy at a minimum ultrasonic energy level each 2 milliseconds in duration. As a further example, the duty cycle associated with soft tissue pulse profile 144C may be 80%. Assuming a pulse frequency of 50 Hz, soft tissue pulse profile 144C may thus be configured to induce ultrasonic energy pulses within ultrasonic instrument 18 each 16 milliseconds in duration and spaced apart by periods of constant ultrasonic energy at a minimum ultrasonic energy level each 4 milliseconds in duration. As another example, the duty cycle associated with soft tissue pulse profile 144E may be 50%. Assuming a pulse frequency of 50 Hz, the soft tissue pulse profile 144E may therefore be configured to induce ultrasonic energy pulses within the ultrasonic instrument 18 that are each 10 milliseconds in duration and are spaced apart by constant ultrasonic energy periods at a minimum ultrasonic energy level that are each 10 milliseconds in duration. Thus, in the example shown in FIG. 7(A), the duration of each significant period of ultrasonic energy maintained at a minimum ultrasonic energy level may be 2 milliseconds or greater (e.g., 4 milliseconds or greater, 10 milliseconds or greater).

[0088] 7(A), each soft tissue pulse profile 144 may also include a coefficient of variation that determines a minimum ultrasonic energy level of the ultrasonic instrument 18 relative to a maximum ultrasonic energy level set for the ultrasonic instrument 18. For example, the coefficient for soft tissue pulse profile 144A may be 80%, indicating that when soft tissue pulse profile 144A is selected, the minimum ultrasonic level of the ultrasonic instrument 18 should be set to a value that is 80% of the maximum ultrasonic energy level. Conversely, the coefficient for soft tissue pulse profile 144C may be 40%, indicating that when soft tissue pulse profile 144C is selected, the minimum ultrasonic level of the ultrasonic instrument 18 should be set to 40% of the maximum ultrasonic energy level.

[0089] 7(B), each of the hard tissue pulse profiles 146 may be configured to induce ultrasonic energy into the ultrasonic instrument 18 including multiple ultrasonic energy pulses spaced apart by ultrasonic energy at a minimum ultrasonic energy level of the ultrasonic instrument 18 determined according to the hard tissue pulse profile 146, with each of the ultrasonic energy pulses peaking at a maximum ultrasonic energy level set for the ultrasonic instrument 18. Contrary to the soft tissue pulse profile 144, the dynamic period of the pulsed ultrasonic energy induced by each hard tissue pulse profile 146 may correspond to the period of time during which the induced ultrasonic energy transitions from the maximum ultrasonic energy level set for the ultrasonic instrument 18, to the minimum ultrasonic energy level set according to the hard tissue pulse profile 146, and back to the maximum ultrasonic energy level. In other words, the dynamic portion of the hard tissue pulse profile 146 may correspond to the adjacent edges of each pair of adjacent ultrasonic energy pulses of the induced ultrasonic energy. 7(B), which may define the shape of the dynamic portion of the ultrasonic energy induced by the hard tissue pulse profile 146, may be set to an inverse Hann pulse shape corresponding to the inverse Hann wave of the dynamic portion. Alternatively, since each of the hard tissue pulse profiles 146 is associated with a hard tissue ablation mode, the pulse shape of each of the hard tissue pulse profiles 146 may exhibit a non-inverted version of a desired shape (e.g., a Hann shape), and the ultrasonic controller 112 may be configured to invert the shape when induced with pulsed ultrasonic energy based on the control console 16 being set to operate in the hard tissue ablation mode.

[0090] As shown in the illustrated example, hard tissue pulse profile 146A may have a 100% duty cycle, and thus the dynamic portion of each cycle of ultrasonic energy induced according to hard tissue pulse profile 146A may span the entire cycle. Conversely, hard tissue pulse profiles 146B-146E may each have a duty cycle less than 100%. Thus, the dynamic portion of each cycle of ultrasonic energy induced according to hard tissue pulse profiles 146B-146E may span only a portion of the cycle, with the remaining portion of the cycle being a constant ultrasonic energy portion during which ultrasonic energy is maintained at a set maximum ultrasonic energy level for a significant period of time. In other words, the constant ultrasonic energy period induced by each hard tissue pulse profile 146 (e.g., pulse profiles 146B-146E) associated with a duty cycle less than 100% may correspond to a period during which ultrasonic energy is maintained at a maximum ultrasonic energy level at the peak of each pulse. The duration of the constant ultrasonic energy portion may vary depending on the hard tissue pulse profile 146 selected. For example, the duration may be 2 milliseconds or greater for some hard tissue pulse profiles 146 and 5 milliseconds or greater for others.

[0091] As an example, the duty cycle associated with hard tissue pulse profile 146B may be 90%. Assuming each hard tissue pulse profile 146 has a pulse frequency of 50 Hz as shown in FIG. 7(B), pulse profile 146B may thus be configured to induce ultrasonic energy where adjacent edges of each pair of adjacent pulses are 18 milliseconds in duration and where each ultrasonic energy pulse peaks at a maximum ultrasonic energy level for a duration of 2 milliseconds. As a further example, the duty cycle of pulse profile 146C may be 80%. Assuming a pulse frequency of 50 Hz, pulse profile 146C may thus be configured to induce ultrasonic energy within ultrasonic instrument 18 including periods of ultrasonic energy that each peak at and are maintained at a maximum ultrasonic energy level set for ultrasonic instrument 18 that is 4 milliseconds in duration, where the ultrasonic energy pulses have constant ultrasonic energy periods spaced apart by dynamic ultrasonic energy periods that are each 16 milliseconds in duration. As another example, the duty cycle of pulse profile 146E may be 50%. Assuming a pulse frequency of 50 Hz, pulse profile 146E may thus be configured to induce ultrasonic energy into ultrasonic instrument 18 that each peaks at a maximum ultrasonic energy level set for ultrasonic instrument 18 that is 10 milliseconds in duration and includes constant ultrasonic energy periods at this maximum ultrasonic energy level, the constant ultrasonic energy periods being spaced apart by dynamic ultrasonic energy periods that are each 10 milliseconds in duration. Thus, in the example shown in FIG. 7(B), the duration of each significant period of ultrasonic energy maintained at the maximum ultrasonic energy level may be 2 milliseconds or more (e.g., 4 milliseconds, 10 milliseconds).

[0092] 7(B), each hard tissue pulse profile 146 may also include a coefficient of variation that determines a minimum ultrasonic energy level of the ultrasonic instrument 18 relative to a maximum ultrasonic energy level set for the ultrasonic instrument 18. For example, the coefficient for hard tissue pulse profile 146A may be 80%, indicating that when hard tissue pulse profile 146A is selected, the minimum ultrasonic level of the ultrasonic instrument 18 should be set to a value that is 80% of the maximum ultrasonic energy level. Conversely, the coefficient for hard tissue pulse profile 146C may be 40%, indicating that when pulse profile 146C is selected, the minimum ultrasonic level of the ultrasonic instrument 18 should be set to a value that is 40% of the maximum ultrasonic energy level.

[0093] The different pulse profiles 144, 146 can provide different operating characteristics, such as different levels of tissue selectivity, temperature control, and tactile feedback. The preferred levels of such operating characteristics may depend on the practitioner's personal preferences and the type of tissue being targeted for ablation. The level of such operating characteristics provided by each pulse profile 144, 146 can be a function of the duty cycle, minimum ultrasonic energy level, and pulse frequency of the pulse profile 144, 146.

[0094] For example, each of the soft tissue pulse profiles 144 shown in FIG. 7A has a different coefficient that determines the minimum ultrasonic energy level and a different duty cycle. The lower the minimum ultrasonic energy level defined by a given soft tissue pulse profile 144 relative to another soft tissue pulse profile 144, assuming other pulse parameters remain constant between the soft tissue pulse profiles 144, the lower the average amplitude and velocity of vibration of the tip 20 that can be induced by the given soft tissue pulse profile 144. Similarly, the lower the duty cycle of a given soft tissue pulse profile 144 relative to another soft tissue pulse profile 144, assuming other pulse parameters remain constant between the soft tissue pulse profiles 144, the lower the average amplitude and velocity of vibration of the tip 20 that can be induced by the given pulse profile 144.

[0095] The lower the average amplitude and velocity of tip 20 vibration induced by a given soft tissue pulse profile 144, the less effective the tip 20 vibration may be at ablating harder tissue, thereby providing increased tissue selectivity and less heat may be generated by the ultrasonic instrument 18 when ablating tissue. In other words, the lower the average amplitude and velocity of tip 20 vibration induced by a given soft tissue pulse profile 144, the greater the ratio of tissue preservation of non-target harder tissue to ablation rate of softer targeted tissue that may be provided.

[0096] Additionally, assuming other pulse parameters remain constant between soft tissue pulse profiles 144, the lower the minimum ultrasonic energy level defined by a given soft tissue pulse profile 144 relative to another soft tissue pulse profile 144, the greater the tactile feedback that a practitioner holding the ultrasonic instrument 18 can feel from the ultrasonic energy induced within the ultrasonic instrument 18 according to the given soft tissue pulse profile 144. Similarly, assuming other pulse parameters remain constant between soft tissue pulse profiles 144, the lower the duty cycle defined by a given soft tissue pulse profile 144 relative to another soft tissue pulse profile 144, the greater the tactile feedback that a practitioner holding the ultrasonic instrument 18 can feel from the ultrasonic energy induced within the ultrasonic instrument 18 according to the given soft tissue pulse profile 144.

[0097] As shown in FIG. 7(A), each of the soft tissue pulse profiles 144 may be associated with a different pulse control level (e.g., level 1-level 5) that may be selected by a practitioner, such as by using the display 74 of the control console 16, to cause the control console 16 to direct ultrasonic energy within the ultrasonic instrument 18 in accordance with the soft tissue pulse profile 144. In some examples, pulse control levels may be assigned to the soft tissue pulse profiles 144 such that each incremental pulse control level is associated with a soft tissue pulse profile 144 that provides increased tissue selectivity, increased temperature control, and / or increased tactile feedback. More specifically, as shown in FIG. 7(A), each selectable pulse control level may be associated with a soft tissue pulse profile 144 that defines a lower minimum ultrasonic energy level and / or duty cycle than the soft tissue pulse profile 144 associated with the preceding selectable pulse control level. Thus, a lower selectable pulse control level may be associated with a soft tissue pulse profile 144 configured to ablate more tissue types, or more specifically, harder tissue, than one associated with a higher pulse control level. The lower selectable pulse control levels may also be associated with soft tissue pulse profiles 144 configured to provide less tactile feedback than those higher in the sequence.

[0098] Sequencing the soft tissue pulse profiles 144 in this manner can provide an intuitive means by which a practitioner may select a soft tissue pulse profile 144 that corresponds to the practitioner's desired operating characteristics. In particular, the practitioner may request increased tissue selectivity and temperature control of the ultrasonic instrument 18 and / or request increased tactile feedback by selecting a relatively high pulse control level, or may request decreased tissue selectivity and temperature control and / or request decreased tactile feedback by selecting a relatively low pulse control level.

[0099] Each of the hard tissue pulse profiles 146 shown in Figure 7(B) similarly defines a different minimum energy factor and duty cycle. Assuming other pulse parameters remain constant between hard tissue pulse profiles 146, the lower the minimum ultrasonic energy level defined by a given hard tissue pulse profile 146 relative to another hard tissue pulse profile 146, the lower the average amplitude and velocity of tip 20 vibration that can be induced by the given hard tissue pulse profile 146. The lower the average and amplitude and velocity of tip 20 vibration induced by a given hard tissue pulse profile 146, the greater the temperature control that can be provided by the given pulse profile 146.

[0100] Additionally, the lower the minimum ultrasonic energy level defined by a given hard tissue pulse profile 146 relative to another hard tissue pulse profile 146, assuming other pulse parameters remain constant between hard tissue pulse profiles 146, the greater the tactile feedback that can be provided to the practitioner from the ultrasonic energy induced in the ultrasonic instrument 18 according to the hard tissue pulse profile 146, such as when placing the vibrating tip 20 against a different tissue. Similarly, the lower the duty cycle defined by a given hard tissue pulse profile 146 relative to another hard tissue pulse profile 146, assuming other pulse parameters remain constant between hard tissue pulse profiles 146, the greater the tactile feedback that can be provided to the practitioner from the ultrasonic energy induced in the ultrasonic instrument 18 according to the hard tissue pulse profile 146, such as when placing the vibrating tip 20 against a different tissue.

[0101] The more tactile feedback the practitioner can feel, the more the practitioner can feel the ultrasonic energy pulses, which can encourage the practitioner to perform a back and forth motion with the ultrasonic instrument 18, which is often desirable when cutting hard tissue. Additionally, because certain tissues, such as soft tissues, may provide increased damping of vibrations felt by the practitioner compared to other tissues, the more tactile feedback the practitioner can feel, the more likely the practitioner will notice when the tip 20 breaks through hard tissue or inadvertently contacts soft tissue during a procedure. Tactile feedback can also be used to indicate to the practitioner that a preferred amount of force is being applied by the practitioner to the ultrasonic instrument 18, as described in more detail below.

[0102] Additionally, assuming other pulse parameters remain constant between hard tissue pulse profiles 146, the lower the minimum ultrasonic energy level defined by a given hard tissue pulse profile 146 relative to another hard tissue pulse profile 146, the greater the likelihood that the tip 20 will stall as the load applied to the tip 20 increases, which may help reduce undesirable ablation and / or necrosis of non-target tissue.

[0103] As shown in FIG. 7(B), each of the hard tissue pulse profiles 146 may be associated with a different pulse control level (e.g., level 1-level 5) that may be selected by a practitioner, such as by using the display 74 of the control console 16, to cause the control console 16 to direct ultrasonic energy within the ultrasonic instrument 18 in accordance with the hard tissue pulse profile 146. In some examples, pulse control levels may be assigned to the hard tissue pulse profiles 146 such that each incremental pulse control level is associated with a hard tissue pulse profile 146 that provides increased tactile feedback and / or a greater likelihood of stalling. More specifically, each selectable pulse control level may be associated with a hard tissue pulse profile 146 that defines a lower minimum ultrasonic energy level and / or a lower duty cycle than the hard tissue pulse profile 146 associated with the preceding selectable pulse control level. Thus, a lower selectable pulse control level may be associated with a hard tissue pulse profile 146 configured to provide less tactile feedback than one associated with a higher selectable pulse control level. The lower sequence selectable pulse control levels may also be associated with hard tissue pulse profiles 146 that are configured to be less likely to stall than those higher sequenced.

[0104] Sequencing the hard tissue pulse profiles 146 in this manner can provide an intuitive means by which a practitioner may select a hard tissue pulse profile 146 that corresponds to the practitioner's desired operating characteristics. For example, a practitioner may request a higher level of tactile feedback and / or stall probability by selecting a pulse control level that is higher in the sequence, and a lower level of tactile feedback and / or stall probability by selecting a pulse control level that is lower in the sequence.

[0105] With further reference to the hard tissue pulse profile 146 shown in FIG. 7(B), the lower the minimum ultrasonic energy level defined by a given hard tissue pulse profile 146 relative to another hard tissue pulse profile 146, assuming other pulse parameters remain constant between hard tissue pulse profiles 146, the lower the average displacement and velocity of the tip 20 that may be induced by the given hard tissue pulse profile 146. Such lower average displacement and velocity may reduce the ablation speed of the ultrasonic instrument 18 when operating on hard tissue. To help maintain a desired ablation speed, as further shown in FIG. 7(B), each incremental pulse control level may also be associated with a hard tissue pulse profile 146 that defines a reduced duty cycle relative to the hard tissue pulse profile 146 associated with the preceding pulse control level. This configuration may function to increase the period during which each hard tissue pulse profile 146 induces ultrasonic energy that is maintained at the maximum ultrasonic energy level set for the ultrasonic instrument 18, which may correspondingly increase the average displacement and velocity of the tip 20 induced by the hard tissue pulse profile 146.

[0106] 7A and 7B each have a similar pulse frequency, i.e., 50 Hz. In an alternative example, two or more of the soft tissue pulse profiles 144 defined by the ultrasonic tool system 12 can have different pulse frequencies, and two or more of the hard tissue pulse profiles 146 defined by the ultrasonic tool system 12 can likewise have different pulse frequencies.

[0107] As an example, FIG. 8(A) illustrates soft tissue pulse profiles 144F-144J associated with different selectable pulse control levels (Level 1-Level 5), with the soft tissue pulse profile 144 associated with each incremental pulse control level providing a lower minimum ultrasonic energy level, a lower duty cycle, and a higher pulse frequency than the soft tissue pulse profile 144 associated with the preceding pulse control level. For example, the soft tissue pulse profiles 144F-144J may have pulse frequencies of 30 Hz, 35 Hz, 45 Hz, 50 Hz, and 55 Hz, respectively. Assuming other pulse parameters remain constant between the soft tissue pulse profiles 144, the greater the pulse frequency defined by a given soft tissue pulse profile 144 relative to another soft tissue pulse profile 144, the greater the tactile feedback that a practitioner holding the ultrasonic instrument 18 may feel from the ultrasonic energy induced within the ultrasonic instrument 18 according to the given soft tissue pulse profile 144. Thus, in addition to each incremental tissue pulse profile 144 providing increased tissue selectivity and temperature control, the difference in the level of tactile feedback provided between each pair of adjacent soft tissue pulse profiles 144 in FIG. 8(A) can be greater than that of the corresponding pair of adjacent soft tissue pulse profiles 144 in FIG. 7(A).

[0108] As a further example, FIG. 8(B) illustrates hard tissue pulse profiles 146F-146J associated with different selectable pulse control levels (Level 1-Level 5), with the hard tissue pulse profile 146 associated with each incremental pulse control level having a lower minimum ultrasonic energy level, a lower duty cycle, and a higher pulse frequency than the hard tissue pulse profile 146 associated with the preceding pulse control level. For example, the hard tissue pulse profiles 146F-146J may have pulse frequencies of 20 Hz, 25 Hz, 30 Hz, 35 Hz, and 40 Hz, respectively. Assuming other pulse parameters remain constant between the hard tissue pulse profiles 146, the greater the pulse frequency defined by a given hard tissue pulse profile 146 relative to another hard tissue pulse profile 146, the greater the tactile feedback that a practitioner holding the ultrasonic instrument may feel from the ultrasonic energy induced within the ultrasonic instrument 18 according to the given hard tissue pulse profile 146. Thus, in addition to each incremental hard tissue pulse profile 146 providing a greater probability of stalling, the difference in the level of tactile feedback provided between each pair of adjacent hard tissue pulse profiles 146 in FIG. 8(B) may be greater than that of the corresponding pair of adjacent hard tissue pulse profiles 146 in FIG. 7(B).

[0109] As shown in the previous example, the various pulse profiles 144, 146 defined by the ultrasonic tool system 12 can include various duty cycles. In an alternative example, the ultrasonic tool system 12 can be configured to implement pulse profiles 144, 146 having the same duty cycle. For example, FIG. 9(A) illustrates soft tissue pulse profiles 144K-144O associated with different selectable pulse control levels (Level 1-Level 5), with the soft tissue pulse profile 144 associated with each incremental pulse control level having a lower minimum ultrasonic energy level, a higher pulse frequency, and the same duty cycle (e.g., 100%) than the soft tissue pulse profile 144 associated with the preceding pulse control level. In this case, each incremental soft tissue pulse profile 144 can continue to provide increased tissue selectivity, temperature control, and tactile feedback, but to a lesser extent than the corresponding soft tissue pulse profile 144 shown in FIG. 8(A). As a corollary, each of the soft tissue pulse profiles 144 shown in FIG. 8(A) having a duty cycle less than 100% can have a lower ablation rate than the corresponding soft tissue pulse profile 144 shown in FIG. 9(A).

[0110] Similarly, FIG. 9(B) illustrates hard tissue pulse profiles 146K-146O associated with different pulse control levels (Level 1-Level 5), with the hard tissue pulse profile 146 associated with each incremental pulse control level having a lower minimum ultrasonic energy level, a higher pulse frequency, and the same duty cycle (e.g., 100%) than the hard tissue pulse profile 146 associated with the preceding pulse control level. In this case, each incremental hard tissue pulse profile 146 may continue to provide increased tactile feedback and stall potential, but the degree of tactile feedback provided by each hard tissue pulse profile 146 may be less than that of the corresponding hard tissue pulse profile 146 shown in FIG. 8(B). As a corollary, each of the hard tissue pulse profiles 146 shown in FIG. 8(B) having a duty cycle less than 100% may have a higher ablation rate than the corresponding hard tissue pulse profile 146 shown in FIG. 9(B), which may provide increased cutting and temperature control relative to the corresponding hard tissue pulse profile 146 of FIG. 8(B).

[0111] In some implementations, the ultrasonic tool system 12 can store a set of soft tissue pulse profiles 144 and a set of hard tissue pulse profiles 146, where the pulse profiles in both sets vary with the same pulse parameters relative to each other. For example, the stored soft tissue pulse profiles 144 can vary in a minimum energy factor, duty cycle, and pulse frequency (e.g., FIG. 8(A)), and the stored hard tissue pulse profile 146 can similarly vary with the same pulse parameters (e.g., FIG. 8(B)). Alternatively, the pulse parameters by which the set of soft tissue pulse profiles 144 vary can be different from the pulse parameters by which the set of hard tissue pulse profiles 146 vary. As an example, the soft tissue pulse profiles 144 can vary with a minimum energy factor, duty cycle, and pulse frequency (e.g., FIG. 8(A)), and the hard tissue pulse profile 146 can vary with a minimum energy factor and pulse frequency, but not with a duty cycle (e.g., FIG. 9(B)). In other words, a set of soft tissue pulse profiles 144 of any one of Figures 7(A), 8(A), and 9(A) can be stored within and implemented by the ultrasonic tool system 12, together with a set of hard tissue pulse profiles 146 of any one of Figures 7(B), 8(B), and 9(B).

[0112] Some of the above exemplary pulse profiles 144, 146, such as those at the highest pulse control levels, may have minimum energy coefficients that correspond to a minimum ultrasonic energy level close to zero, such as pulse profiles 144E, 146E, 144J, and 144O of Figures 7(A), 7(B), 8(A), and 9(A), respectively. However, as shown in the illustrated example, the minimum energy coefficients of these pulse profiles 144, 146 may be set such that the minimum ultrasonic energy level does not drop all the way to zero, but instead drops just above zero. This may be done so that the ultrasonic energy induced in the ultrasonic instrument 18 does not reach a level at which the control console 16 is unable to track the resonant frequency of the ultrasonic instrument 18. In other words, the minimum ultrasonic level defined by these pulse profiles 144, 146 may be set such that the vibrations induced in the tip 20 are large enough for the control console 16 to detect the vibrations and track the resonant frequency of the ultrasonic instrument 18. For example, the minimum energy factor of these pulse profiles 144, 146 can be set such that the peak-to-peak oscillation of the tip head 22 corresponding to a minimum ultrasonic energy level is greater than 5 microns and less than 20 microns, e.g., about 10 microns. In other words, the minimum energy factor of these pulse profiles 144, 146 can be set to 3% or greater and / or a minimum mechanical current i induced in the ultrasonic instrument 18. M can be set to be greater than 2 milliamps and less than 10 milliamps, for example, about 5 milliamps.

[0113] In response to the selection of a given pulse profile 140, the ultrasonic controller 112 may be configured to cause the control console 16 to generate and supply to the ultrasonic instrument 18 an AC drive signal that induces ultrasonic energy within the ultrasonic instrument 18 in accordance with the selected pulse profile 140. Specifically, and referring again to FIG. 4, the ultrasonic controller 112 may be configured to communicate one or more control signals to the signal generator 114 that cause the signal generator 114 to generate an AC signal across the primary winding 124 that corresponds to the selected pulse profile 140, or, more specifically, induce an AC drive signal across the secondary winding 126, which in turn induces ultrasonic energy within the ultrasonic instrument 18 in accordance with the selected pulse profile 140.

[0114] For example, in response to receiving a selection of a given pulse profile 140, the ultrasound controller 112 may be configured to retrieve the pulse profile 140, or more specifically, the pulse parameter settings of the pulse profile 140, from the console storage 118. The ultrasound controller 112 may also be configured to generate and store a modulated waveform corresponding to the retrieved pulse profile 140, such as in the modulation DDS 150 of the signal generator 114. The modulation DDS 150 may include a memory device that stores a sample array with values ​​that form the modulated waveform. The modulated waveform may range from 0 to 1, inclusive, and may have a shape and length that corresponds to one cycle of the pulse pattern represented by the selected pulse profile 140.

[0115] More specifically, the modulated waveform may include an instance of a transition function associated with the pulse shape parameter settings for the selected pulse profile 140 that starts at zero and peaks at one. If the selected pulse profile 140 has a 100% duty cycle, the transition function may span the entire modulated waveform. Otherwise, the transition function may span along a portion of the modulated waveform such that the length of the transition function relative to the length of the modulated waveform corresponds to the duty cycle. In this case, the remaining portion of the modulated waveform may be a constant period maintained at a constant value such as zero or one. For example, if the selected pulse profile 140 is the soft tissue pulse profile 144 shown in FIG. 7(A), FIG. 8(A), or FIG. 9(A), the remaining portion may be set to zero, and if the selected pulse profile 140 is the hard tissue pulse profile 146 shown in FIG. 7(B), FIG. 8(B), or FIG. 9(B), the remaining portion may be set to one. As an example, FIG. 10 illustrates a modulated waveform that may be generated and stored by the ultrasound controller 112 upon selection of the soft tissue pulse profile 144E shown in FIG. 7(A).

[0116] In response to actuation of the ultrasonic instrument 18, such as via depression of the foot pedal 76, the ultrasonic controller 112 may be configured to communicate the target ultrasonic frequency to the signal generator 114, or more specifically to the base DDS 152 of the signal generator 114. The base DDS 152 may store a sample array that forms a sinusoidal waveform having a frequency equal to or greater than the maximum ultrasonic frequency that can be provided to the ultrasonic instrument 18. From this sample array, the base DDS 152 may be configured to generate a base AC signal 154. The base AC signal 154 may be a sinusoidal signal having a frequency equal to the target ultrasonic frequency indicated by the ultrasonic controller 112, and may have a substantially constant amplitude, such as unity.

[0117] Initially, the target ultrasonic frequency communicated by the ultrasonic controller 112 may be a predetermined target frequency, which may be retrieved from the ultrasonic instrument 18, as described in more detail below. The ultrasonic controller 112 may then be configured to implement a loop that tracks a frequency corresponding to a target vibration characteristic (e.g., resonance) of the ultrasonic instrument 18, as described above, and communicate a control signal to the base DDS 152 that adjusts the frequency of the base AC signal 154 generated by the base DDS 152 according to the tracked frequency. FIG. 11 illustrates a base AC signal 154A that may be generated by the base DDS 152.

[0118] Additionally, upon operation of the ultrasonic instrument 18, the ultrasonic controller 112 may be configured to determine maximum and minimum ultrasonic energy levels of the induced ultrasonic energy, as described above. The ultrasonic controller 112 then controls the mechanical current i induced in the ultrasonic instrument 18 according to the selected pulse profile 140. M The ultrasonic controller 112 may be configured to implement a loop that adjusts the magnitude of ultrasonic energy induced within the ultrasonic instrument 18 in accordance with the selected pulse profile 140, such as by adjusting the maximum ultrasonic energy level and the minimum ultrasonic energy level. The iterations of the loop may function to determine a target ultrasonic energy waveform of the induced ultrasonic energy based on a maximum ultrasonic energy level and a minimum ultrasonic energy level, and generate an AC drive signal based on the target ultrasonic energy waveform. Specifically, the ultrasonic controller 112 may be configured to determine a scalar based on the determined maximum ultrasonic energy level and the determined minimum ultrasonic energy level, multiply the modulated waveform by the scalar, and add the determined minimum ultrasonic energy level to the result of the multiplication to generate the target ultrasonic energy waveform. The ultrasonic controller 112 may then be configured to compare the target ultrasonic energy waveform to the ultrasonic energy being induced within the ultrasonic instrument 18 to determine an error therebetween, and adjust the base AC signal 154 with the scalar 156 to minimize the error, such as using a PID controller.

[0119] At a more granular level, for each iteration of the loop, the ultrasonic controller 112 adjusts the target mechanical current i based on the maximum and minimum ultrasonic energy levels of the induced ultrasonic energy. M In particular, the ultrasonic controller 112 may be configured to determine a scalar based on the maximum ultrasonic energy level and the minimum ultrasonic energy level, such as by determining the difference therebetween. The ultrasonic controller 112 may then be configured to take samples from a sample array of the modulating DDS 150 and multiply the modulated waveform samples by the scalar. The ultrasonic controller 112 may then subtract the minimum ultrasonic energy level from the product of the multiplication to determine the target ultrasonic energy level of the ultrasonic instrument 18, or more specifically, the target machine current i M A value can be generated.

[0120] Concurrently with determining the target ultrasonic energy level, the ultrasonic controller 112 also controls the machine current i based on feedback data corresponding to the applied AC drive signal, as described above. M The ultrasonic controller 112 may be configured to determine the ultrasonic energy level being induced in the ultrasonic instrument 18, such as by calculating a value of the target ultrasonic energy level. The ultrasonic controller 112 may then be configured to compare the target ultrasonic energy level and the determined ultrasonic energy level being induced in the ultrasonic instrument 18 to determine an error therebetween, and generate a voltage scalar 156 that, when multiplied by the base AC signal 154, minimizes the error, such as using a PID controller.

[0121] For each iteration of the loop, the ultrasonic controller 112 may draw sample values ​​from the modulated waveform sample array according to the order of the samples in the array. The sampling rate at which the ultrasonic controller 112 draws sample values ​​from the modulated waveform sample array may depend on the size of the modulated waveform array relative to the pulse frequency of the selected pulse profile 140 and the time of each iteration of the loop, which may be 400 microseconds in one example. For example, if the size of the modulated waveform sample array multiplied by the loop time is equal to the period represented by the pulse frequency, then for each iteration of the loop, the ultrasonic controller 112 may draw the sample value immediately following the previously drawn sample value in the modulated waveform array. Conversely, if the size of the modulated waveform sample array multiplied by the loop time is greater than the period represented by the pulse frequency, the ultrasonic controller 112 may draw samples at a relatively fast sampling rate, such as by skipping samples in the array (e.g., drawing every fifth sample). As a further example, if the size of the modulated waveform sample array multiplied by the loop time is less than the period represented by the pulse frequency, the ultrasonic controller 112 may derive samples at a relatively slower sampling rate, such as by using a given sample for multiple iterations of the loop. As described in more detail below, the ultrasonic controller 112 may be configured to adjust the pulse frequency during a procedure, for example as a function of the load being applied to the ultrasonic instrument 18, which can cause the ultrasonic controller 112 to adjust the sampling rate.

[0122] As previously mentioned, the maximum ultrasonic energy level, and correspondingly the minimum ultrasonic energy level, of the directed pulsed ultrasonic energy may vary during a treatment, for example, as a result of the practitioner adjusting the set power level and / or the depression level of the foot pedal 76. It should be appreciated that the above algorithm allows the control console 16 to account for such variations without modifying the modulation waveform stored in the modulation DDS 150, thereby improving the responsiveness of the system.

[0123] The signal generator 114 may further include a multiplier 158 configured to receive the base AC signal 154 and multiply it with the generated scalar 156 to generate a modulated AC signal 160. The modulated AC signal 160 may be communicated to a D / A converter 162 and then through an amplifier 164, which may receive a power signal from a power source 165 regulated by the ultrasonic controller 112. The amplifier 164 may generate a corresponding AC signal across the primary winding 124 of the transformer 116. As one example, the amplifier 164 and power source 165 may be configured as described in commonly owned U.S. Patent No. 10,449,570, the contents of which are incorporated herein by reference in their entirety.

[0124] The AC signal across the primary winding 124 can induce an AC drive signal across the secondary winding 126, which in turn induces ultrasonic energy within the ultrasonic instrument 18 according to the selected pulse profile 140. In other words, the AC signal across the primary winding 124 can induce an AC drive signal across the secondary winding 126, which in turn induces ultrasonic energy within the ultrasonic instrument 18 comprising a plurality of ultrasonic energy pulses, each of the pulses peaking at a maximum ultrasonic energy level determined for the ultrasonic instrument 18 and spaced apart by ultrasonic energy at a minimum ultrasonic energy level defined according to the selected pulse profile 140. FIG. 12(A) illustrates an AC signal 165A that may be generated across the primary winding 124 by the signal generator 114, such as upon selection of the soft tissue pulse profile 144E shown in FIG. 7(A). FIG. 12(B) illustrates another AC signal 165B that may be generated across the primary winding 124 by the signal generator 114, such as upon selection of the soft tissue pulse profile 144A shown in FIG. 7(A).

[0125] In an alternative embodiment, the base DDS 152 can be configured to generate the base AC signal 154 to have an amplitude corresponding to the tracked ultrasonic frequency indicated by the ultrasonic controller 112 and the maximum ultrasonic energy level set for the ultrasonic instrument 18. In particular, the ultrasonic controller 112 can be configured to implement a loop that determines the error between the determined maximum ultrasonic energy level and the measured ultrasonic energy level induced in the ultrasonic instrument, and provide a scalar to the base DDS 152 that minimizes the error. In this case, the modulating waveform generated and stored in the modulating DDS 150 can range between 1 and a minimum energy factor for the selected pulse profile 140. The signal generator 114 can then be configured to multiply the base AC signal 154 with the modulating waveform to generate the modulated AC signal 160.

[0126] 4 and 5, the control console 16 may also include a memory reader 166 that communicates with one or more electronic memory storage devices integrated with the ultrasonic instrument 18. The ultrasonic instrument 18 may include one or more electronic memory storage devices that store data that identifies the ultrasonic instrument 18, or more specifically the hand piece 24 and / or tip 20, and defines operating parameter settings specific to the ultrasonic instrument 18, or more specifically the hand piece 24 and / or tip 20. Non-limiting examples of such operating parameters include the maximum drive current of the AC drive signal, the machine current i M the maximum current of the AC drive signal, the maximum drive voltage of the AC drive signal, the maximum drive frequency of the AC drive signal, the minimum drive frequency of the AC drive signal, and the capacitance C of the driver 30 O , PID coefficients that regulate the AC drive signal, usage history, and whether the ultrasonic instrument 18, or more specifically the tip 20, is pulse capable. The one or more memory devices integral with the ultrasonic instrument 18 may also indicate whether the tip 20 coupled to the handpiece 24 is configured to ablate soft or hard tissue, and may indicate one or more pulse profiles 140 specific to the tip 20.

[0127] For example, the hand piece 24 of the ultrasonic instrument 18 may include a hand piece (HP) memory 168 disposed therein. By way of non-limiting example, the HP memory 168 may be an EPROM, an EEPROM, or an RFID tag. In response to connecting the ultrasonic instrument 18 to the control console 16, the ultrasonic controller 112 may be configured to read data stored in the HP memory 168 using the memory reader 166 and adjust the operation of the control console 16 based on the data. More specifically, the control console 16 may include a communication interface, such as a coil 170 connected to the memory reader 166. The coil 170 may be integrated with the socket 40 of the control console 16. The HP memory 168 may be connected to a coil 172, which may in turn be integrated with the adapter 38 of the cable 36. When the ultrasonic instrument 18 is connected to the control console 16 via the cable 36, the coils 170, 172 may align and inductively exchange signals. The ultrasound controller 112 may then be configured to read data from and write data to the HP memory 168 via the coils 170 , 172 .

[0128] Memory reader 166 may be configured to convert the signal across coil 170 into a data signal readable by ultrasound controller 112. Memory reader 166 may also be configured to receive data to be written to HP memory 168 from ultrasound controller 112 and to generate a signal across coil 170 that causes the data to be written to HP memory 168. The structure of memory reader 166 may be complementary to the structure of HP memory 168. Thus, continuing with the non-limiting example above, memory reader 166 may be an assembly that can read data from and write data to an EPROM, EEPROM, or RFID tag.

[0129] In addition to, or alternatively to, the HP memory 168, the ultrasonic instrument 18 may include a chip memory 174. As mentioned above, the tip 20 may be removable from the handpiece 24, such that the handpiece 24 may be used with interchangeable tips 20, where different tips 20 may have different operational limitations and intended uses. For example, some tips 20 may be configured to cauterize soft tissue, while other tips 20 may be configured to cauterize hard tissue, such as fibrous tissue and bone. Thus, the HP memory 168 may store data identifying the handpiece 24, as well as the capacitance C of the driver 30. O , and the chip memory 174 can store operational parameter settings specific to the tip 20, including data identifying the tip 20 currently coupled to the hand piece 24 and whether the tip 20 is configured to cauterize soft tissue or cut hard tissue such as bone, and / or pulse parameter settings of the pulse profile 140 specific to the tip 20. Because the tip 20 and irrigated sleeve 42 may be distributed together as a single package, the chip memory 174 may be located within the irrigated sleeve 42, or more specifically, the sleeve body 44. The chip memory 174 can be the same type of memory as the HP memory 168 (e.g., an EPROM, EEPROM, or RFID tag).

[0130] In response to connecting an ultrasonic instrument 18 to the control console 16, the ultrasonic controller 112 may be configured to read the data stored in the HP memory 168 and the chip memory 174 using the memory reader 166 and tailor the operation of the control console 16 to the particular handpiece 24 and tip 20 combination coupled to the control console 16. The chip memory 174 may contain the same settings for the operating parameters as the HP memory 168. To the extent that the settings (which may also be referred to as values) for a given operating parameter differ between the HP memory 168 and the chip memory 174, the ultrasonic controller 112 may be configured to manage the operation of the ultrasonic instrument 18 utilizing the more specific value. Additionally or alternatively, to the extent that both the HP memory 168 and the chip memory 174 contain values ​​for the same operating parameter, the ultrasonic controller 112 may be configured to manage the operation of the ultrasonic instrument 18 for the operating parameter based on a combination of values ​​stored in the memory (e.g., summing the values, averaging the values).

[0131] Similar to the HP memory 168, the ultrasound controller 112 can read data from and write data to the chip memory 174 via the memory reader 166 and the coil 170. In particular, the handpiece 24 can include two conductors 176 that extend from the proximal end to the distal end of the handpiece 24. The proximal end of the conductor 176 can be coupled to a coil 172 that can be integrated with the adapter 38 of the cable 36. The distal end of the conductor 176 can be coupled to another coil 178 located at the distal end of the handpiece 24. A corresponding coil 180 can be located at the proximal end of the irrigation sleeve 42, or more specifically, the sleeve body 44. When the irrigation sleeve 42 is placed around the tip 20 and mated to the handpiece 24, the coils 178, 180 can align and inductively exchange signals. Then, when the handpiece 24 is connected to the control console 16 via the cable 36, the coils 170, 172 can also align and inductively exchange signals. The ultrasound controller 112 can then read data from and write data to the chip memory 174 via conductors 176 via inductive communication provided by coils 170 , 172 and coils 178 , 180 .

[0132] In some implementations, rather than the pulse profile 140 being pre-stored in the console storage 118, the chip memory 174 may store data indicative of a pulse profile 140 specific to the tip 20. For example, if the tip 20 is designed to ablate soft tissue, the chip memory 174 may store one or more soft tissue pulse profiles 144 specific to the tip 20. Alternatively, if the tip 20 is designed to ablate hard tissue, the chip memory 174 may store one or more hard tissue pulse profiles 146 specific to the tip 20. In either case, in response to the ultrasonic instrument 18 being coupled to the control console 16, the ultrasonic controller 112 may be configured to retrieve the pulse profile 140 from the chip memory 174 and store it in the console storage 118 and / or memory 122 for selection by a user.

[0133] The ultrasonic controller 112 may also be coupled to and configured to drive the display 74 of the control console 16. In particular, the ultrasonic controller 112 may be configured to generate information and user interface (UI) components for presentation on the display 74. Such information displayed on the display 74 may include information identifying the handpiece 24 and tip 20, as well as information describing the operational status of the ultrasonic tool system 12. If the display 74 is a touch screen display, the ultrasonic controller 112 may also be configured to cause the display 74 to display images of buttons and other practitioner-selectable components. By manipulating the buttons and other practitioner-selectable components, the practitioner may set desired operating parameters of the ultrasonic tool system 12, such as those described herein.

[0134] 13 illustrates a process 200 for controlling vibration of an ultrasonic instrument 18 in accordance with a selected pulse profile 140. The control console 16, or more specifically the ultrasonic controller 112, may be configured to implement the process 200, such as during execution of software 123 embodied by computer-executable instructions present in the console storage 118.

[0135] In block 202, a maximum ultrasonic energy level of the induced ultrasonic energy may be determined. The maximum ultrasonic energy level is determined by the maximum mechanical current i of the ultrasonic instrument 18. M can be defined, and correspondingly, the maximum amplitude and speed of vibration of the tip 20 can be defined. The maximum ultrasonic energy level of the ultrasonic instrument 18 is the maximum ultrasonic energy level that the ultrasonic instrument 18 is rated to accommodate, also referred to herein as the maximum possible ultrasonic energy level of the ultrasonic instrument 18, or the machine current i M The maximum possible ultrasonic energy level of the ultrasonic instrument 18 may be based on a global ultrasonic energy limit, which may similarly be defined by: In response to the ultrasonic instrument 18 being connected to the control console 16, the control console 16 may be configured to read from the ultrasonic instrument 18, or more specifically, from the HP memory 168 and / or the chip memory 174, the maximum possible ultrasonic energy level of the ultrasonic instrument 18.

[0136] The maximum ultrasonic energy level determined in block 202 can also be based on a power setting of the ultrasonic instrument 18 input by the practitioner. For example, the practitioner can operate the display 74 or remote control 80 of the ultrasonic tool system 12 to input a power setting of the ultrasonic instrument 18, which can indicate a percentage of a maximum possible ultrasonic energy level to limit the operation of the ultrasonic instrument 18. In response to receiving the percentage, the ultrasonic controller 112 can be configured to determine a maximum ultrasonic energy level for the ultrasonic instrument 18 by applying the percentage to the maximum possible ultrasonic energy level. In some examples, the ultrasonic controller 112 can further base the maximum ultrasonic energy level on the depression angle of the foot pedal 76. Specifically, the depression angle of the foot pedal 76 can indicate to the ultrasonic controller 112 a percentage of the ultrasonic energy level corresponding to the user-inputted power setting to use as the maximum ultrasonic energy level.

[0137] The practitioner can set the power settings and / or maximum ultrasonic energy levels of the ultrasonic instrument 18 based on the practitioner's personal preferences and the type of tissue targeted for ablation. As an example, for a given surgical procedure, the practitioner can target certain types of soft tissue for ablation via cavitation while avoiding ablation of other types of soft tissue. In this case, the practitioner can set the control console 16 to limit the operation of the ultrasonic instrument 18 to ultrasonic energy levels that cause cavitation of the targeted tissue type while avoiding cavitation of other tissue types. For example, for a brain surgical procedure, the practitioner may desire to ablate one or more of the dura, blood vessel walls, arachnoid, pia, white matter, or gray matter tissue while leaving other types of tissue intact. The ultrasonic instrument 18 can function to cavitate these types of tissue when the ultrasonic energy induced into the ultrasonic instrument 18 is approximately 27% of the maximum possible ultrasonic energy level of the ultrasonic instrument 18. Thus, the practitioner may set the control console 16 to limit the operation of the ultrasonic instrument 18 to 30% of the maximum possible ultrasonic energy level of the ultrasonic instrument 18 .

[0138] Combining a practitioner selected power setting and / or maximum ultrasonic energy level with one of the pulse profiles 140 may further help reduce potential trauma to tissue types desired to remain intact. For example, continuing with the above example, and referring to FIG. 7(A), if the control console 16 is set to limit operation of the ultrasonic instrument 18 to 30% of the maximum possible ultrasonic energy level of the ultrasonic instrument 18, the maximum ultrasonic energy level induced by each soft tissue pulse profile 144 may correspond to 30% of the maximum possible ultrasonic energy level of the ultrasonic instrument 18, as shown by the 100% line. In this case, each soft tissue pulse profile 144 may function to cavitate the target tissue when the ultrasonic energy induced by the soft tissue pulse profile 144 is at or above a "cavitation threshold" that is close to the maximum ultrasonic energy level of the soft tissue pulse profile 144, which may correspond to 27% of the maximum possible ultrasonic energy level of the ultrasonic instrument 18, as discussed above. The minimum ultrasonic energy level induced by each soft tissue pulse profile 144 shown in FIG. 7(A) may be below the cavitation threshold. In this manner, each soft tissue pulse profile 144 can cyclically induce sufficient ultrasonic energy to cause cavitation in the target tissue, while inducing reduced ultrasonic energy levels that function to reduce the temperature and ablation of tissue types that are desired to remain intact.

[0139] 13, at block 204, a determination may be made as to whether a pulsed mode is enabled for the ultrasonic instrument 18. Specifically, the practitioner may operate the control console 16, such as by using the display 74 or remote control device 80, to enable and disable the pulsed mode, and the ultrasonic controller 112 may be configured to make this determination based on the practitioner settings provided. In response to determining that the pulsed mode is not enabled (the "NO" branch of block 204), at block 206, the control console 16 may be configured to operate the ultrasonic instrument 18 in a continuous mode, such as according to the constant energy profile 148 described above. Specifically, upon operation of the ultrasonic instrument 18, the ultrasonic controller 112 may be configured to generate and supply to the ultrasonic instrument an AC drive signal that induces ultrasonic energy within the ultrasonic instrument 18 that is maintained at a determined maximum ultrasonic energy level of the ultrasonic instrument 18.

[0140] Additionally or alternatively, determining whether the pulse mode is enabled may include determining whether the tip 20 itself is pulse-capable. In particular, some tips 20 releasably coupleable to the hand piece 24 may be configured to operate only in a continuous mode. Whether the tip 20 is pulse-capable may be indicated as data stored in the chip memory 174 that is specific to the tip 20. Thus, in response to an ultrasonic instrument 18 being coupled to the control console 16, the ultrasonic controller 112 may be configured to read data from the chip memory 174 to determine whether the tip 20 currently coupled to the hand piece 24 is pulse-capable. In some examples, the data stored in the chip memory 174 may directly indicate whether the tip 20 is pulse-capable. In other examples, the chip memory 174 may indicate a chip type, such as via an identifier unique to the chip 20, and the ultrasonic controller 112 may be configured to query data stored in the console storage 118 that corresponds to the chip type to determine whether the tip 20 is pulse-capable. If not, the ultrasound controller 112 may be configured to override this option from the practitioner and configure the control console 16 to operate the ultrasonic instrument 18 in continuous mode as described above.

[0141] Alternatively, in response to determining that the tip 20 is pulse-enabled and / or that a pulsed mode has been selected (the "Yes" branch of block 204), a determination can be made in block 208 whether the ultrasonic instrument 18 should be operated in a soft tissue ablation mode or a hard tissue ablation mode. As previously mentioned, each mode can be associated with a different set of pulse profiles 140 specifically designed for that mode. A practitioner can set the control console 16 to either mode using a user interface associated with the control console 16, such as the display 74 or remote control device 80, and the ultrasonic controller 112 can be configured to make this determination based on the practitioner settings provided.

[0142] Alternatively, the tip memory 174 distributed with the current tip 20 coupled to the handpiece 24 of the ultrasonic instrument 18 may contain data indicating whether the tip 20 is configured for soft or hard tissue ablation. The data stored in the tip memory 174 may directly indicate whether the tip 20 is configured for soft or hard tissue ablation, or may indicate the type of tip 20 corresponding to data stored in the console storage 118 indicating whether the tip type is for soft or hard tissue ablation. The control console 16 may be configured to read such data from the chip memory 174 when the ultrasonic instrument 18 is connected to the control console 16, as described above, to determine whether the ultrasonic instrument 18 should be operated in a soft or hard tissue ablation mode.

[0143] In response to determining that the ultrasonic instrument 18 is to be operated in a soft tissue ablation mode (the “Soft Tissue” branch of block 208), the control console 16 may be configured to operate in a soft tissue ablation mode in block 210. For example, the ultrasonic controller 112 may be configured to set a flag in the console storage 118 and / or memory 122 corresponding to the control console 16 being set in the soft tissue ablation mode. In response to determining that the ultrasonic instrument 18 is to be operated in a hard tissue ablation mode (the “Hard Tissue” branch of block 208), the control console 16 may be configured to operate in a hard tissue ablation mode in block 212. For example, the ultrasonic controller 112 may be configured to set a flag in the console storage 118 and / or memory 122 corresponding to the control console 16 being set in the hard tissue ablation mode.

[0144] At block 214, a practitioner selection of one of the pulse profiles 140 associated with the currently set ablation mode may be received. As previously described, the console storage 118 may store a plurality of soft tissue pulse profiles 144 associated with the soft tissue ablation mode and a plurality of hard tissue pulse profiles 146 associated with the hard tissue ablation mode. The various soft tissue pulse profiles 144 associated with the soft tissue ablation mode may be ordered, for example, according to a user selectable pulse control level assigned to the soft tissue pulse profile 144 such that each incremental soft tissue pulse profile 144 provides increasing tissue selectivity, temperature control, and / or haptic feedback, and the various hard tissue pulse profiles 146 associated with the hard tissue ablation mode may be ordered, for example, according to a user selectable pulse control level assigned to the hard tissue pulse profile 146 such that each incremental hard tissue pulse profile 146 provides increasing haptic feedback regarding the tissue being contacted and how much force the practitioner is applying with the ultrasonic instrument 18 and / or increasing stall likelihood. Thus, the practitioner can select one of the pulse profiles 140 associated with the currently set ablation mode of the control console 16 by selecting a pulse control level of the pulse profile 140, such as via the display 74 or remote control device 80, based on the operating characteristics of the ultrasonic instrument 18 desired by the practitioner.

[0145] In response to receiving a practitioner selection of one of the pulse profiles 140 associated with a configured ablation mode of the control console 16 at block 216, pulse parameter settings associated with the selected pulse profile 140 may be determined by the ultrasonic controller 112, such as by querying the console storage 118 based on the selected pulse profile 140. Alternatively, the ultrasonic controller 112 may be configured to determine such pulse parameter settings based on data retrieved from a chip memory 174, which is specific to the chip 20 and can store pulse parameter settings of pulse profiles 140 that are user selectable when the ultrasonic instrument 18 is connected to the control console 16.

[0146] One or more system parameters may be set based on the retrieved pulse parameter settings and / or the set ablation mode at block 218. For example, the ultrasonic controller 112 may be configured to determine a minimum ultrasonic energy level for the ultrasonic instrument 18 based on the determined pulse parameter settings, or more specifically, a minimum energy factor indicated by the determined parameter settings.

[0147] As a further example, because fragmenting soft tissue typically does not require as much fragmentation power as fragmenting hard tissue, such as bone, the ultrasonic controller 112 can be configured to reduce the available power, such as by setting the voltage limit of the AC drive signal to a lower value, when the selected pulse profile 140 corresponds to a soft tissue ablation mode. Specifically, when the selected pulse profile 140 corresponds to a soft tissue ablation mode, the ultrasonic controller 112 may be configured to set the voltage limit of the AC drive signal to a relatively low value (e.g., 600 volts peak), and when the selected pulse profile 140 corresponds to a hard tissue ablation mode, the ultrasonic controller 112 may be configured to set the voltage limit of the AC drive signal to a relatively high value (e.g., 1200 volts peak). Alternatively, each pulse profile 140 can include pulse parameter settings specific to the pulse profile 140 that indicate voltage limitations for use of the pulse profile 140.

[0148] As a further example, the machine current i of the ultrasonic tool system 12 M The rate of change limit of is determined by the control console 16 determining the rate of change of the previously induced machine current i M From the new target machine current i M The rate at which the ultrasonic energy is induced can be adjusted. The machine current i utilized when operating in continuous ultrasonic energy mode M The rate of change limit of the machine current i may not be fast enough for the pulse mode, and therefore the ultrasonic controller 112 may adjust the machine current i in response to the ultrasonic tool system 12 being set to the pulse mode and the pulse profile 140 being selected. M The rate of change limit of the machine current i set for a given pulse profile 140 may be configured to be set to a higher value. M The rate of change limits of may depend on the pulse shape, pulse frequency, and duty cycle of the pulse profile 140. Thus, in response to the selection of a given pulse profile 140, the ultrasonic controller 112 may use a formula or other method to vary the machine current i by varying varying values ​​of these parameters. Mbased on these parameters, such as by storing data relating to the rate of change limits of the machine current i M The system may be configured to set a limit on the rate of change of

[0149] As another example, during operation of the ultrasonic instrument 18, the voltage of the power signal supplied by the power source 165 may vary according to the voltage induced across the primary winding 124 to enable the amplifier 164 to generate a desired AC signal across the primary winding 124. To improve system responsiveness, the ultrasonic controller 112 can be configured to adjust the voltage of the signal supplied by the power source 165 to the amplifier 164 based on the voltage developed across the primary winding 124, as opposed to, or in addition to, using a PID controller for the power source 165 that waits for a feedback signal indicative of the varied voltage. The adjustment of the voltage of the signal supplied by the power source 165 may be subject to a positive rate of change limit, and the ultrasonic controller 112 can be configured to implement a higher rate of change limit (e.g., 2x) for this signal when operating in a pulsed mode rather than a continuous energy mode.

[0150] In some examples, such as when the control console 16 is configured to operate in a hard tissue ablation mode, rather than the maximum ultrasonic energy level of the ultrasonic instrument 18 being set equal to a level set by the practitioner, such as via a user power setting and foot pedal 76, the ultrasonic controller 112 can be configured to determine the maximum ultrasonic energy level of the ultrasonic instrument 18 such that it is greater than the practitioner-set level and the average ultrasonic energy level induced within the ultrasonic instrument 18 in accordance with a selected pulse profile 140 is substantially equal to the practitioner-set level. This technique can result in higher ablation rates and higher minimum ultrasonic energy levels for each pulse profile 140, which can help prevent excessive stalling when treating hard tissue, such as bone.

[0151] At block 220, an AC drive signal may be generated and delivered to the ultrasonic instrument 18 based on the determined maximum and minimum ultrasonic energy levels and other pulse parameter settings of the selected pulse profile 140, as described above. Specifically, the AC drive signal may be set to induce ultrasonic energy within the ultrasonic instrument 18 having multiple ultrasonic energy pulses that peak at a maximum ultrasonic energy level and are spaced apart by ultrasonic energy at a minimum ultrasonic energy level in accordance with the duty cycle and pulse frequency of the selected pulse profile 140.

[0152] As an example, in response to selection of one of the soft tissue pulse profiles 144 (e.g., soft tissue pulse profiles 144B-144E of FIG. 7A, soft tissue pulse profiles 144G-144J of FIG. 8A) having a duty cycle of less than 100%, the control console 16 can be configured to generate an AC drive signal to induce ultrasonic energy within the ultrasonic instrument 18 that includes ultrasonic energy pulses that peak at a set maximum ultrasonic energy level and are spaced apart for a significant period (e.g., a period of 2 milliseconds or more) at a minimum ultrasonic energy level. The duration of each ultrasonic energy pulse relative to the duration of each cycle of the induced ultrasonic energy can correspond to the duty cycle associated with the selected soft tissue pulse profile 144.

[0153] As another example, in response to a selection of a hard tissue pulse profile 146 associated with a duty cycle less than 100% (e.g., pulse profiles 146B-146E of FIG. 7B and pulse profiles 146G-146J of FIG. 8B), the control console 16 can be configured to generate an AC drive signal to induce ultrasonic energy within the ultrasonic instrument 18 including ultrasonic energy pulses that peak at a maximum ultrasonic energy level and are spaced apart by a momentary period (e.g., less than 1 millisecond) of ultrasonic energy at a minimum ultrasonic energy level. The peak of each ultrasonic energy pulse can include a significant period (e.g., a period of 2 milliseconds or more) at the maximum ultrasonic energy level. The duration of each pair of adjacent edges of adjacent ultrasonic energy pulses can correspond to the duty cycle associated with the selected hard tissue pulse profile 146.

[0154] As a further example, in response to selection of a pulse profile 140 having a 100% duty cycle (e.g., pulse profile 144A of FIG. 7(A), pulse profile 144F of FIG. 8(A), pulse profiles 144K-144O of FIG. 9(A), pulse profile 146A of FIG. 7(B), pulse profile 146F of FIG. 8(B), and pulse profiles 146K-146O of FIG. 9(B)), the control console 16 may be configured to generate an AC drive signal to induce ultrasonic energy into the ultrasonic instrument 18, including ultrasonic energy pulses spaced by momentary periods at a minimum ultrasonic energy level (e.g., less than 1 millisecond), each of which momentarily peaks at a maximum ultrasonic energy level (e.g., less than 1 millisecond). In other words, the level of ultrasonic energy induced into the ultrasonic instrument 18 can be considered to be constantly rising and falling.

[0155] In some embodiments, while pulsed ultrasonic energy is being directed into the ultrasonic instrument 18, the control console 16 may display a toggle element that allows the practitioner to quickly switch between directing pulsed ultrasonic energy according to a currently selected pulse profile 140 and directing ultrasonic energy into the ultrasonic instrument 18 according to a continuous ultrasonic energy mode (e.g., according to a constant energy profile 148), for example, without having to shut down the ultrasonic instrument 18 or cross each of the pulse control levels to disable pulsing. This feature may allow the practitioner to temporarily increase the fragmentation power and then quickly return to pulsed ultrasonic energy, such as when the practitioner encounters tissue that is difficult to ablate under the current settings.

[0156] FIG. 14 illustrates a method 250 of providing tactile feedback to a practitioner using ultrasonic energy pulses induced within the ultrasonic instrument 18 to indicate whether the practitioner is providing an optimal amount of pressure to the ultrasonic instrument 18. When a practitioner applies a vibrating tip 20 of the ultrasonic instrument 18 to tissue, such as bone, the pressure the practitioner applies to the ultrasonic instrument 18 can affect the effectiveness of the tip 20 in ablating the tissue. If the practitioner applies too little pressure, the tip 20 may not ablate the tissue efficiently, and if the practitioner applies too much pressure, the tip 20 may potentially cauterize tissue that is desired to remain intact and / or may stall. The control console 16, or more specifically the ultrasonic controller 112, can be configured to implement the method 250 to provide tactile feedback to the practitioner indicating whether the pressure being applied by the practitioner is too little, too much, or on target.

[0157] In block 252, targeted ultrasonic energy may be directed into the ultrasonic instrument 18 according to an ultrasonic energy profile selected, for example, by the practitioner. For example, if one of the pulse profiles 140 is selected to be directed into the ultrasonic instrument 18, the control console 16 may be configured to direct pulsed ultrasonic energy into the ultrasonic instrument 18 according to the selected pulse profile 140, with the ultrasonic energy pulses occurring at a default pulse frequency (e.g., 50 Hz) as the targeted ultrasonic energy. In some examples, each pulse profile 140 may define a default pulse frequency specific to the pulse profile 140. Alternatively, the control console 16 may be configured to use the same default pulse frequency for each pulse profile 140. Conversely, if the pulse mode is disabled by the practitioner, the control console 16 may be configured to direct continuous ultrasonic energy into the ultrasonic instrument 18 according to the constant energy profile 148, etc. as the targeted ultrasonic energy.

[0158] At block 254, the load applied to the ultrasonic instrument 18, or more specifically, the mechanical components of the ultrasonic instrument 18, may be monitored. The magnitude of the load applied to the mechanical components of the ultrasonic instrument 18 may be a function of the physical properties of the tissue contacted by the tip 20 and the force applied to the ultrasonic instrument 18 by the practitioner. As the practitioner applies increased pressure to the ultrasonic instrument 18, the load applied to the mechanical components may increase and as the practitioner applies decreased pressure to the ultrasonic instrument 18, the load applied to the mechanical components may decrease.

[0159] The ultrasonic controller 112 can be configured to monitor the load applied to the ultrasonic instrument 18 by calculating a load measurement indicative of the degree of applied load. In some examples, the load measurement is calculated based on the mechanical impedance Z exhibited by the ultrasonic instrument 18 during operation. M or mechanical resistance R M6A and 6B, when the ultrasonic instrument 18 is operating at resonance (e.g., the base frequency of the AC drive signal, which corresponds to the frequency of the base AC signal 154 of the signal generator 114, is substantially equal to the resonant frequency of the ultrasonic instrument 18), the mechanical impedance Z of the ultrasonic instrument 18 may be expressed as M The induced component L M and the capacitance component C M can cancel each other. Thus, when the ultrasonic instrument 18 is operating at resonance, the mechanical impedance Z of the ultrasonic instrument 18 M is the machine current i M and the voltage of the AC drive signal v S The mechanical resistance R of the ultrasonic instrument 18 can be calculated using Ohm's law based on M can be equal to

[0160] Thus, the ultrasonic controller 112 may be configured to calculate the mechanical current i of the ultrasonic instrument 18 as determined using equation (1) above when the ultrasonic instrument 18 is operating at resonance. M , and the voltage v of the AC drive signal as measured using voltage measurement circuit 134. S Based on the mechanical resistance R of the ultrasonic instrument 18 M By Ohm's law, the mechanical impedance Z of the ultrasonic instrument 18 can be determined as M is the driving voltage v S The machine current i M It can be equal to the mechanical impedance Z M is the mechanical resistance at resonance R M Therefore, the control console 16 can determine when the ultrasonic instrument 18 is operating at resonance by setting the drive voltage v S The machine current i M The mechanical resistance R of the ultrasonic instrument 18 is calculated by dividing M It can be configured to calculate:

[0161] As another example, the load measurement may be the voltage v of the AC drive signal, as measured using voltage measurement circuit 134. S As previously mentioned, the control console 16 may generate a target mechanical current i in the ultrasonic instrument 18. M The voltage of the AC drive signal, v, is S The ultrasonic instrument 18 can be configured to adjust the mechanical current i M is the mechanical impedance Z of the ultrasonic instrument 18 during operation. M or mechanical resistance R M Therefore, the voltage of the AC drive signal, v S is the mechanical impedance Z presented by the ultrasonic instrument 18 during operation M or mechanical resistance R M , and correspondingly can increase or decrease with the load applied to the mechanical components of the ultrasonic instrument 18.

[0162] 14, at block 256, a determination may be made as to whether an optimal load is being applied to the ultrasonic instrument 18, or more specifically, to the mechanical components of the ultrasonic instrument 18. To this end, the control console 16 may be configured to determine whether the monitored applied load is within a target range defined by a predetermined lower load threshold level (TH1) and a predetermined upper load threshold level (TH2). More specifically, the control console 16 may be configured to determine whether the monitored applied load is greater than or equal to the lower threshold level (TH1) and / or less than or equal to the upper threshold level (TH2). As previously discussed, the applied load may be a function of the amount of pressure applied by the practitioner to the ultrasonic instrument 18. A monitored applied load less than the lower threshold level TH1 may indicate that the practitioner is providing less than optimal pressure to ablate tissue, and a monitored applied load greater than the upper threshold level TH2 may indicate that the practitioner is providing more than optimal pressure to ablate tissue. If the monitored applied load is within the target range, the control console 16 can be configured to determine that an optimal load is being applied to the ultrasonic instrument 18 (the "Yes" branch of block 256).

[0163] The control console 16 may be configured to determine whether the monitored applied load is within a target range by being configured to determine whether a load measurement defining the monitored applied load is within a target range. Thus, the lower threshold TH1 and the upper threshold TH2 may be defined in units of the load measurement. For example, if the load measurement is in units of the voltage v of the AC drive signal, S Alternatively, the lower threshold level TH1 and the upper threshold level TH2 may be defined by a voltage threshold in volts, where the load measurement corresponds to the mechanical impedance Z of the ultrasonic instrument 18. M or mechanical resistance R M For example, and without limitation, if the load measurement corresponds to the mechanical resistance R of the ultrasonic instrument 18, then the lower threshold level TH1 and the upper threshold level TH2 may be defined by a mechanical impedance threshold or a mechanical resistance threshold in ohms.M , the lower threshold level TH1 may be 2000 ohms and the upper threshold level TH2 may be 5000 ohms.

[0164] In some implementations, the ultrasonic controller 112 may be configured to calibrate the load measurement prior to determining whether the value is within a target range based on the level (e.g., flow rate) of irrigation fluid being provided through the sleeve 42, which may be set by the practitioner and / or monitored by the control console 16, and / or based on the type of tissue being contacted by the working end 22 of the tip 20, which may be detected as described in more detail below, and the like. More specifically, each of these items may affect the load on the mechanical components of the ultrasonic instrument 18 and increase or decrease the load measurement accordingly. Thus, the console storage 118 may store data indicative of values ​​that offset (e.g., reduce) the load measurement for different irrigation fluid settings / measurements and / or different detected tissue types being contacted in order to normalize the values. Additionally or alternatively, such data may be represented within a memory device (e.g., chip memory 174) of the ultrasonic instrument 18 and read by the ultrasonic controller 112 when the ultrasonic instrument 18 is connected with the control console 16. Additionally or alternatively, the ultrasound controller 112 can be configured to determine the offset normalization value by instructing the practitioner to vibrate the tip 20 in free air prior to treatment and / or without irrigation, measuring corresponding load measurements during such vibration, and using them as offset values ​​to normalize the load measurements later in the treatment.

[0165] In response to determining that the monitored applied load is optimal (the “Yes” branch of block 256), the method 250 may return to block 252 and continue to direct targeted ultrasonic energy within the ultrasonic instrument 18, monitor the applied load, and determine whether the monitored applied load is optimal. In response to determining that the monitored applied load is not optimal (e.g., the monitored applied load is less than the lower threshold level TH1 or greater than the upper threshold level TH2) (the “No” branch of block 256), tactile feedback may be provided to the practitioner indicative of such condition in block 258.

[0166] For example, in response to a determination that the monitored applied load is less than the lower threshold level TH1, the control console 16 may be configured to induce pulsed ultrasonic energy within the ultrasonic instrument 18 at a relatively high or low pulse frequency, and in response to a determination that the monitored applied load is greater than the upper threshold level TH2, the control console 16 may be configured to induce pulsed ultrasonic energy within the ultrasonic instrument 18 at the other of the relatively high or low pulse frequency. For example, without limitation, in response to a determination that the monitored applied load is less than the lower threshold level TH1, the control console 16 may be configured to induce pulsed ultrasonic energy within the ultrasonic instrument 18 at a relatively high pulse frequency of 60 Hz, and in response to a determination that the monitored applied load is greater than the upper threshold level TH2, the control console 16 may be configured to induce pulsed ultrasonic energy within the ultrasonic instrument 18 at a relatively low pulse frequency of 10 Hz. In this example, if the practitioner provides too little pressure (e.g., the monitored applied load is below the lower threshold level TH1), the practitioner may feel a relatively fast pulse at the ultrasonic device 18, and if the practitioner provides too much pressure (e.g., the monitored applied load is greater than the upper threshold level TH2), the practitioner may feel a relatively slow pulse at the ultrasonic device 18.

[0167] If the targeted ultrasonic energy induced in block 252 is pulsed ultrasonic energy corresponding to pulse profile 140, then in block 258, in response to determining that the monitored applied load is less than a lower threshold level TH1, the control console 16 may be configured to induce pulsed ultrasonic energy within the ultrasonic instrument 18 in accordance with the selected pulse profile 140, but at a pulse frequency greater (or less) than a default pulse frequency associated with the selected pulse profile 140. In other words, the control console 16 may be configured to induce a relatively high (or relatively low) pulse frequency. Similarly, in response to determining that the monitored applied load is greater than an upper threshold level TH2, the control console 16 may be configured to induce pulsed ultrasonic energy within the ultrasonic instrument 18 in accordance with the selected pulse profile 140, but at a pulse frequency greater (or less) than a default pulse frequency associated with the selected pulse profile 140. In other words, the control console 16 may be configured to induce a relatively low (or relatively high) pulse frequency.

[0168] In an alternative embodiment, if the targeted ultrasonic energy induced in block 252 is pulsed ultrasonic energy corresponding to pulse profile 140, in response to determining that the monitored applied load is less than a lower threshold level TH1 or greater than an upper threshold level TH2, the control console 16 can be configured to transition to induced ultrasonic energy maintained at a substantially constant value, such as a determined maximum ultrasonic energy level of the ultrasonic instrument 18 (e.g., constant energy profile 148, FIG. 7(A)).

[0169] Conversely, if the targeted ultrasonic energy is substantially constant ultrasonic energy, in response to determining in block 258 that the monitored applied load is less than the lower threshold level TH1 or greater than the upper threshold level TH2, the control console 16 can be configured to transition to directing pulsed ultrasonic energy into the ultrasonic instrument 18 in accordance with one of the pulse profiles 140, such as at a pulse frequency equal to a default pulse frequency associated with the pulse profile 140, or equal to a relatively higher or lower pulse frequency as described above.

[0170] More specifically, assuming the targeted ultrasonic energy is substantially constant ultrasonic energy, in response to determining in block 256 that the monitored applied load is less than the lower threshold level TH1 or greater than the upper threshold level TH2, the control console 16 may be configured to determine in block 258 whether the currently connected tip 20 is configured to ablate hard tissue or soft tissue, such as based on user provided settings or data retrieved from the tip memory 174. The control console 16 may then be configured to induce one of the soft tissue pulse profiles 144 in response to determining that the tip 20 is configured to ablate soft tissue, and to induce one of the pulse profiles 146 in response to determining that the tip 20 is configured to cut bone.

[0171] The pulse frequency of the directed pulsed ultrasonic energy may be set to a default pulse frequency associated with the pulse profile 140 (e.g., 50 Hz) or may be set based on whether the monitored applied load is determined to be below a lower threshold level TH1 or greater than an upper threshold level TH2, as described above. For example, in response to determining that the monitored applied load is below a lower threshold level TH1, the control console 16 may be configured to direct a relatively high pulse frequency (e.g., 60 Hz), and in response to determining that the monitored applied load is greater than an upper threshold level TH2, the control console 16 may be configured to direct a relatively low pulse frequency (e.g., 10 Hz), or vice versa.

[0172] Following block 258, the method 250 may return to block 254 to continue monitoring the applied load and comparing it to the target range to determine whether the applied load is optimal. In response to a determination ("Yes" branch of block 256) that the monitored applied load is now optimal (e.g., greater than or equal to the lower threshold level TH1 and less than or equal to the upper threshold level TH2), the method 250 may return to block 252 where targeted ultrasonic energy may again be directed into the ultrasonic instrument 18 to indicate to the practitioner that an optimal amount of pressure is being applied. In other words, the control console 16 may direct ultrasonic energy into the ultrasonic instrument 18 corresponding to the ultrasonic energy profile and associated settings selected by the practitioner.

[0173] For example, if the practitioner selects one of the pulse profiles 140 to be induced into the ultrasonic instrument 18 as the targeted ultrasonic energy, the control console 16 may be configured to induce the selected pulse profile 140 at a pulse frequency equal to the default pulse frequency associated with the pulse profile 140. Alternatively, if the practitioner selects a constant energy profile 148 to be induced into the ultrasonic instrument 18, the control console 16 may be configured to induce constant ultrasonic energy into the ultrasonic instrument 18. In either case, the practitioner may feel a resumption of the targeted ultrasonic energy in the ultrasonic instrument 18 and may associate such resumption with an indication that the practitioner is providing optimal pressure to the ultrasonic instrument 18.

[0174] In some examples, each pulse profile 140 may be associated with a range of pulse frequencies between a relatively high pulse frequency and a relatively low pulse frequency to induce in response to the magnitude of the monitored applied load within the target range. In other words, as the monitored applied load varies within the target range, the control console 16 may be configured to determine and induce a varying pulse frequency within the ultrasonic instrument 18 as a function of the degree to which the monitored applied load varies.

[0175] For example, with reference to Fig. 15, the console storage 118 or chip memory 174 may store data defining a graph 270 that associates various load measurements between a lower threshold level TH1 and an upper threshold level TH2 with a specific pulse frequency that is induced in the ultrasonic instrument 18 when the load measurements are generated. For example, the data may indicate a lower threshold level TH1 272, a relatively high pulse frequency 274 associated with the lower threshold level TH1 272, an upper threshold level TH2 276, a relatively low pulse frequency 278 associated with the upper threshold level TH2 276, and a transition function 280. In the example shown in Fig. 15, the load measurements are provided in units of ohms. In alternative examples, the load measurements may be provided in other units, such as volts, as discussed above.

[0176] The transition function 280 may extend across load measurements between the lower threshold level TH1 272 and the upper threshold level TH2 276 from a relatively high pulse frequency 274 associated with the lower threshold level TH1 272 to a relatively low pulse frequency 278 associated with the upper threshold level TH2 276. In other words, the transition function 280 may associate each load measurement greater than or equal to the lower threshold level TH1 272 and less than or equal to the upper threshold level TH2 276 with a unique pulse frequency. The transition function 280 may be a decreasing function, such as a linear function with a negative slope, such that as the load measurement increases, the associated pulse frequency decreases.

[0177] The control console 16 may be configured to induce pulsed ultrasonic energy within the ultrasonic instrument 18 at varying pulse frequencies determined based on the above data. In particular, assuming that the practitioner selects one of the pulse profiles 140 to be induced within the ultrasonic instrument 18 in response to actuation of the ultrasonic instrument 18, the control console 16 may be configured to induce pulsed ultrasonic energy within the ultrasonic instrument 18 in accordance with the selected pulse profile 140 and at a pulse frequency equal to a default pulse frequency (e.g., 50 Hz) associated with the selected pulse profile 140. The control console 16 may then be configured to repeat a cycle of monitoring the loads applied to the mechanical components of the ultrasonic instrument 18, determining an updated pulse frequency to induce within the ultrasonic instrument 18 based on the monitored applied loads and the graph 270, and generating pulsed ultrasonic energy within the ultrasonic instrument 18 in accordance with the selected pulse profile 140 and the updated pulse frequency.

[0178] For example, the monitored applied load may be a function of the mechanical resistance R M The control console 16 then calculates the mechanical resistance R Mis less than or equal to a lower threshold level TH1 272, is greater than or equal to an upper threshold level TH2 276, or is between the lower threshold level TH1 272 and the upper threshold level TH2 276. M In response to determining that the mechanical resistance R is less than or equal to the lower threshold level TH1 272, the control console 16 may be configured to set the pulse frequency of the pulsed ultrasonic energy induced within the ultrasonic instrument 18 to a relatively high pulse frequency 274, M In response to determining that the mechanical resistance R is greater than or equal to the upper threshold level TH2 276, the control console 16 can be configured to set the pulse frequency of the pulsed ultrasonic energy induced within the ultrasonic instrument 18 to a relatively low pulse frequency 278. M In response to determining that the mechanical resistance R is between the lower threshold level TH1 272 and the upper threshold level TH2 276, the control console 16 adjusts the pulse frequency of the pulsed ultrasonic energy induced within the ultrasonic instrument 18 relative to the mechanical resistance R M 2. The pulse frequency may be configured to be set as shown by the transition function 280 as a function of

[0179] In this manner, if the pressure applied by the practitioner to the ultrasonic instrument 18 deviates from a specified optimal pressure level, which may be indicated by a load measurement varying from a predetermined load measurement (e.g., 3000 ohms) between the lower threshold level TH1 272 and the upper threshold level TH2 276, the pulse frequency of the pulsed ultrasonic energy induced within the ultrasonic instrument 18 may vary instantly and to the extent that the applied pressure differs from the specified optimal pressure level. As a result, the practitioner may immediately receive tactile feedback indicating the discrepancy from the specified optimal pressure level and may determine, based on the level of the tactile feedback, an amount of pressure to add to or remove from the ultrasonic instrument 18 to provide the specified optimal pressure level. For example, and without limitation, the predetermined load measurement between the lower threshold level TH1 272 and the upper threshold level TH2 276 corresponding to the specified optimal pressure level may be set to the average of the lower threshold level TH1 272 and the upper threshold level TH2 276, or may be set to a load measurement corresponding to the average or median of the range of pulse frequencies defined by the transition function 280.

[0180] 15, the lower threshold level TH1 272 is associated with a relatively high pulse frequency 274 and the upper threshold level TH2 276 is associated with a relatively low pulse frequency 278, with the transition function 280 decreasing from the relatively high pulse frequency 274 to the relatively low pulse frequency 278 as the load measurement increases. As another example, it is contemplated that the lower threshold level TH1 272 may be associated with a relatively low pulse frequency 278 and the upper threshold level TH2 276 may be associated with a relatively high pulse frequency 274, with the transition function 280 increasing from the relatively low pulse frequency 278 to the relatively high pulse frequency 274 as the load measurement increases.

[0181] In some embodiments, rather than or in addition to defining targeted ultrasonic energy to be induced when the applied load is within a target range, the practitioner may be able to define targeted ultrasonic energy to be induced when the applied load is outside of a target range. In this manner, in response to determining that the applied load is outside of the target range, indicating that the practitioner may not be applying optimal pressure to the ultrasonic instrument 18, the control console 16 may be configured to induce practitioner-defined out-of-range targeted ultrasonic energy within the ultrasonic instrument 18. Conversely, if the monitored applied load is within the target range, the practitioner may be applying optimal pressure to the ultrasonic instrument 18, and the control console 16 may be configured to provide tactile feedback indicative of such condition, such as by inducing practitioner-defined in-range targeted ultrasonic energy within the ultrasonic instrument 18.

[0182] For example, if the out-of-range targeted ultrasonic energy directed into the ultrasonic instrument 18 follows the constant energy profile 148 described above, the control console 16 may be configured to direct pulsed ultrasonic energy into the ultrasonic instrument 18 according to, for example, one of the pulse profiles 140 selected by the practitioner as the in-range targeted ultrasonic energy. In this manner, in response to the monitored applied load corresponding to the target range, the ultrasonic instrument 18 may begin to exhibit vibrations corresponding to the practitioner-selected pulse profile 140. If the out-of-range targeted ultrasonic energy directed into the ultrasonic instrument 18 follows one of the pulse profiles 140, the control console 16 may be configured to adjust the pulse frequency of the pulsed ultrasonic energy, such as by increasing the pulse frequency or decreasing the pulse frequency relative to the pulse frequency of the out-of-range targeted ultrasonic energy directed into the ultrasonic instrument 18 when the applied load is within the target range.

[0183] In some examples, the pulse frequency of the pulsed ultrasonic energy induced when the monitored applied load is within the target range may also vary based on the distance between the load measurement and the lower threshold level TH1 and the distance between the load measurement and the upper threshold level TH2. For example, in response to the load measurement moving from a predetermined load value between the lower threshold level TH1 or the upper threshold level TH2 to near the lower threshold level TH1 or the upper threshold level TH2, the control console 16 may be configured to induce a higher pulse frequency. Similarly, in response to the load measurement moving from the lower threshold level TH1 or the upper threshold level TH2 toward the predetermined load value, the control console 16 may be configured to induce a lower pulse frequency. This configuration may also be reversed such that a movement of the load measurement from a predetermined load value toward the lower threshold level TH1 or the upper threshold level TH2 causes a lower pulse frequency, and a movement from the lower threshold level TH1 or the upper threshold level TH2 toward the predetermined load value causes a higher pulse frequency. The control console 16 may be configured to adjust the pulse frequency in this manner according to a transition function that takes values ​​between the lower and upper threshold levels TH1 and TH2 as inputs and defines a particular pulse frequency for each load measurement between the lower and upper threshold levels TH1 and TH2, such as a bell curve function that peaks at a predetermined load value. For example, and without limitation, the predetermined load value may be set to the average of the lower and upper threshold levels TH1 and TH2, or to a load measurement that corresponds to the average or median of the pulse frequency defined by the transition function.

[0184] 16, in some implementations, the control console 16 can be configured to operate in various practitioner-selectable pulse activation modes that automatically disable and enable pulsing based on the monitored load relative to a lower threshold level TH1 and an upper threshold level TH2. For example, in pulse activation mode 1, the control console 16 can be configured to direct pulsed ultrasonic energy according to one of the pulse profiles 140 selected by the practitioner when the monitored load is outside of a target range, and to direct substantially constant ultrasonic energy when the monitored load is within the target range. Conversely, in pulse activation mode 2, the control console 16 can be configured to direct pulsed ultrasonic energy according to one of the pulse profiles 140 selected by the practitioner when the monitored load is within the target range, and to direct substantially constant ultrasonic energy when the monitored load is outside of the target range. Pulse activation mode 0 can correspond to automatic pulse activation being disabled.

[0185] The above-mentioned pulse parameters, i.e., lower threshold level TH1 and upper threshold level TH2, can be pre-determined and stored in the console storage 118. In some examples, each pulse profile 140 can define a lower threshold level TH1 and an upper threshold level TH2 that are specific to the pulse profile 140. Alternatively, the control console 16 can be configured to use the same lower threshold level TH1 and upper threshold level TH2 for each pulse profile 140. In further embodiments, rather than or in addition to a user-selectable pulse activation mode, each pulse profile 140 can define a particular pulse activation mode (e.g., mode 1 or 2) available for the pulse profile 140, and the practitioner can select between the defined pulse activation mode or the disabled pulse activation mode when using that pulse profile 140.

[0186] As discussed above throughout this disclosure, different tips 20 having different operating characteristics can be releasably coupled to the hand piece 24. Because each tip 20 is typically distributed with an irrigation sleeve 42 that is unique to the tip 20, to provide further optimization, optimized settings of pulse parameters as described herein specific to each tip 20 removably coupleable to the hand piece 24 can be pre-determined and stored in a chip memory 174 of the irrigation sleeve 42 distributed with the tip 20. Thereafter, when an ultrasonic instrument 18 including a tip 20 is coupled to the control console 16, the control console 16 can be configured to read data from the chip memory 174 indicative of the set pulse parameters specific to the tip 20 and operate the ultrasonic instrument 18 based on the read data, as discussed above.

[0187] For example, the data stored in the chip memory 174 for a given chip 20 may indicate one or more pulse profiles 140 specific to the chip 20 that may be selectable by the practitioner. To this end, the data stored in the chip memory 174 may indicate one or more pulse parameter settings specific to the chip 20, including one or more minimum energy coefficients specific to the chip 20, each of which may be associated with a different pulse profile 140 specific to the chip 20, one or more duty cycles specific to the chip 20, each of which may be associated with a different pulse profile 140 specific to the chip 20, one or more pulse frequencies specific to the chip 20, each of which may be associated with a different pulse profile 140 specific to the chip 20, one or more pulse shapes specific to the chip 20, each of which may be associated with a different pulse profile 140 specific to the chip 20, and one or more voltage limits specific to the chip 20, each of which may be associated with a different pulse profile 140 specific to the chip 20.

[0188] The data stored in tip memory 174 for a given tip 20 may also indicate one or more other pulse parameter settings specific to the tip 20, such as whether the tip 20 is pulse-enabled, whether the tip 20 is a hard or soft tissue ablation tip, a lower threshold level TH1 for the tip 20, an upper threshold level TH2 for the tip 20, and a pulse activation mode for the tip 20. In response to an ultrasonic instrument 18 including a tip 20 being coupled to the control console 16, the control console 16 may be configured to read this data from the tip memory 174 and utilize the indicated pulse parameter settings, as described above.

[0189] As a further example, the console storage 118 may also be configured to store the above-described pulse parameters by chip type. In this case, in response to an ultrasonic instrument 18 being coupled to the control console 16, the control console 16 may be configured to determine the type of chip 20, such as from data indicative of the chip type read from the chip memory 174. The control console 16 may then be configured to query the console storage 118 for chip-type specific pulse parameter settings and utilize such pulse parameter settings, as described above.

[0190] 17 illustrates components that may be incorporated into the tissue detection control console 86 of the tissue detection system 13. The tissue detection control console 86 may include a controller 302, an optical module 304, and a power supply 306. The power supply 306 may be configured to provide power to various other components of the tissue detection control console 86 to enable their operation. The functionality of each of the other components is described in more detail below.

[0191] The optical module 304 may include an optical block 308, a spectrometer 310, and one or more excitation sources 312. In response to receiving a corresponding command from the tissue detection controller 302, the excitation source(s) 312 may illuminate tissue being contacted by the operative end 22 of the tip 20 of the ultrasonic instrument 18 with excitation light via the excitation fiber 94. For example, the excitation source(s) 312 may be configured to emit blue light at about 405 nm or blue light in the range of 400 nm to 500 nm. The excitation source(s) 312 may also be configured to emit excitation light corresponding to other wavelengths, such as wavelengths associated with the remainder of the visible light spectrum other than blue light (e.g., greater than 500 nm but less than 700 nm), wavelengths associated with the ultraviolet light spectrum (less than 400 nm), and / or wavelengths associated with the infrared light spectrum (greater than 700 nm). The excitation source(s) 312 may further include various types of light sources, including, but not limited to, light emitting diodes (LEDs), pulsed lasers, continuous wave lasers, modulated lasers, and / or filtered white light sources.

[0192] The optical block 308 may include multiple optical paths that direct light between the sample element 88 and components to the optical module 304. More specifically, the optical block 308 may include optical paths configured to direct light emitted from the excitation source(s) 312 to the excitation fiber 94 and the directing fiber 100, and may also include optical paths configured to direct fluorescence collected by the excitation fiber 94 to the spectrometer 310. The spectrometer 310 may be configured to convert the collected optical signals into electrical signals. More specifically, the spectrometer 310 may be configured to photoelectrically convert each wavelength of the collected optical signals into electrical signals (also referred to herein as spectral signals), which may then be provided to the tissue detection controller 302 for analysis.

[0193] The tissue detection controller 302 can be configured to implement the functions, features, and processes of the tissue detection control console 86 described herein. More specifically, similar to the ultrasound controller 112, the tissue detection controller 302 can include a processor 314 and a memory 316, which can include and / or be communicatively coupled to the storage 318 of the tissue detection control console 86, each configured similarly as described above in connection with the ultrasound controller 112. The processor 314 can similarly operate under the control of a software program 317 embodied by computer executable instructions that, when executed by the processor 314, cause the processor 314 to implement the functions, features, and processes of the tissue detection control console 86 described herein. In this manner, the tissue detection controller 302, or more specifically, the processor 314, can be configured to periodically operate the optical module 304 to excite tissue contacted by the working end 22 of the tip 20 of the ultrasonic instrument 18, collect fluorescence emitted from the tissue as a result of the tissue being excited, and convert the collected fluorescence into a spectral signal for analysis.

[0194] The tissue detection controller 302, or more specifically the processor 314, may also be configured to evaluate the electrical signal to determine characteristics of the tissue. To this end, the storage 318 may include tissue map data 320 that correlates characteristics of the spectral signal (e.g., frequency, intensity) with various tissue characteristics indicated by the spectral signal, such as tissue type (e.g., whether the contacted tissue is considered healthy or unhealthy tumor tissue and / or whether the tissue corresponds to a blood vessel), which may correspondingly indicate whether the contacted tissue is a target or non-target for ablation. Thus, the tissue detection controller 302, or more specifically the processor 314, may be configured to access the tissue map data 320 to determine characteristics of the tissue being contacted by the tip 20 of the ultrasonic instrument 18 based on the fluorescence collected by the sample element 88.

[0195] In some examples, the tissue map data 320 may define multiple tissue maps, each associated with a different anatomical structure (e.g., brain, spine), with each tissue map correlating characteristics of the spectral signal with tissue properties in the context of the associated anatomical structure. In this case, the tissue detection controller 302, or more specifically the processor 314, may be configured to receive, such as via user input, an indication of a given patient anatomical structure involved in the surgical procedure, and to query a tissue map associated with the indicated patient anatomical structure to determine tissue properties.

[0196] Tissue detection system 13 may incorporate other features and functionality such as, but not limited to, those described in applicant's International Application No. PCT / IB2022 / 052294, filed March 14, 2022, and published as WO 2022 / 190076, the contents of which are incorporated herein by reference in their entirety.

[0197] 4 and 17, the ultrasound controller 112 and the tissue detection controller 302 may be communicatively coupled to one another. In this manner, at least one of the controllers 112, 302 may be configured to communicate its determined tissue characteristics to the other controller 112, 302, for example, to facilitate display and comparison of the tissue characteristics determined by the respective controller 112, 302. These features are described in more detail with reference to the methods below.

[0198] As mentioned above, and referring again to FIG. 1 , the surgical system 10 can also include a navigation system 14 and an imaging system 15. As will be appreciated from the following description, the surgical system 10 can be configured to, among other things, enable a surgeon to visualize, approach, and treat or otherwise manipulate the anatomical structures of the patient P at the target site TS with a high level of control. To this end, imaging data of the target site TS may be acquired via the imaging system 15 and can be used to assist the surgeon in visualizing the anatomical structures of the patient P at or otherwise adjacent to the target site TS. The imaging data can also be utilized by the navigation system 14 to facilitate navigation of the ultrasonic instrument 18 relative to the target site TS, further enhancing the tissue detection features described herein.

[0199] In the illustrative example of FIG. 1, a minimally invasive spinal procedure, such as a posterior interbody spinal fusion procedure, is being performed on a patient P. It is understood that this example is intended to be illustrative and that other types of surgical procedures are contemplated. In this exemplary surgical procedure, an ultrasonic instrument 18 may be used to ablate intervertebral disc tissue and cartilage endplate tissue. In other examples, the navigation system 14 may be configured to track the position and / or orientation of the ultrasonic instrument 18 as it operates to cut bone, such as the skull, or to ablate tumor tissue, such as in the brain. As the ultrasonic instrument 18 contacts tissue of various characteristics, such as non-target (e.g., healthy) tissue and / or target (e.g., tumor) tissue, the surgical system 10 may be configured to correlate tissue characteristic(s) determined by the ultrasonic tool system 12 and / or tissue detection system 13 with the tracked position and / or orientation of the ultrasonic instrument 18 to provide enhanced guidance to the practitioner and additional data points to verify the accuracy of tissue detection.

[0200] As described above, the imaging system 15 may be used to acquire imaging data of a patient P, which may be a human or animal patient. As shown in the representative configuration illustrated in FIG. 1 , the imaging system 15 may be implemented as an X-ray computed tomography (CT) imaging device. The patient P may be placed in a central bore 506 of the imaging system 15, and an X-ray source and detector may rotate around the central bore 506 to acquire raw X-ray imaging data of the patient P. The imaging data may be processed using an imaging controller 508 or another suitable controller to construct three-dimensional imaging data, two-dimensional imaging data, etc., which may be transmitted to or otherwise utilized by the navigation system 14.

[0201] Imaging data may be acquired pre-operatively (e.g., before performing a surgical procedure) and / or intra-operatively (e.g., during a surgical procedure) by positioning the patient P in a central bore 506 of the imaging system 15. To acquire imaging data, a portion of the imaging system 15 may be moved relative to a patient support 510 (e.g., a surgical table) on which the patient P is positioned while the patient P remains stationary. Here, the patient support 510 may be fixed to the imaging system 15, such as via a post 512 attached to a base 514 of the imaging system 15. A portion of the imaging system 15 including at least one imaging element (e.g., an O-shaped imaging gantry 516) may be supported by an articulatable support 518 that can translate along the length of the base 514 on rails 520 to perform an imaging scan of the patient P, and can be translated out of the way away from the patient P to perform a surgical procedure on the patient P.

[0202] An exemplary imaging system 15, which may be used in a variety of configurations, is the AIRO™ Intra-Operative CT System manufactured by Mobius Imaging, LLC. Examples of X-ray CT imaging devices that may be used in accordance with various configurations of the present disclosure are described in U.S. Pat. No. 10,151,810, entitled "Pivoting Multi-directional X-ray Imaging System with a Pair of Diametrically Opposite Vertical Support Columns Tandemly Movable Along a Stationary Base Support," U.S. Pat. No. 9,962,132, entitled "Multi-directional X-ray Imaging System with Single Support Column," U.S. Pat. No. 9,801,592, entitled "Caster System for Mobile Apparatus," U.S. Pat. No. 9,111,379, entitled "Method and System for X-ray CT Imaging," U.S. Pat. No. 8,118,488, entitled "Mobile Medical Imaging System and Methods," and U.S. Patent Application Publication No. 2014 / 0275953, entitled "Mobile X-ray Imaging System," the disclosures of each of which are incorporated herein by reference in their entireties.

[0203] Although the illustrated imaging system 15 is implemented as an X-ray CT imaging device, in other configurations, the imaging system 15 can include one or more of an X-ray fluoroscopic imaging device, a magnetic resonance (MR) imaging device, a positron emission tomography (PET) imaging device, a single photon emission computed tomography (SPECT), or an ultrasound imaging device. Other configurations are also contemplated. In some configurations, the imaging system 15 can be a mobile CT device that is not attached to a patient support 510 and can be wheeled or otherwise moved over the patient P and the patient support 510 to perform a scan. Examples of mobile CT devices include the BodyTom™ CT scanner from Samsung Electronics Co., Ltd. and the O-arm™ surgical imaging system from Medtronic, plc. The imaging system 15 can also be a C-arm X-ray fluoroscopic device. In other configurations, the imaging system 15 can be a fixed bore imaging device, and the patient P can be moved into the bore of the device, either on a patient support 510 or on a separate patient table configured to slide in and out of the central bore 506. Additionally, although the imaging system 15 shown in Figure 1 is located near the patient P in the operating room, the imaging system 15 can be located remotely, such as in another room or building (e.g., the radiology department of a hospital).

[0204] The surgical system 10 may employ a navigation system 14 to track the movement of various objects, such as, among other things, the ultrasonic instrument 18 and portions of the anatomy of the patient P (e.g., tissue within or adjacent to the target site TS), and in some configurations, portions of the imaging system 15. To this end, the navigation system 14 may include a localizer 522 and a navigation controller 524 coupled to the localizer 522. The localizer 522 and the navigation controller 524 may be configured to cooperate to track the position and / or orientation of a tracker 526 disposed within the surgical workspace relative to the objects of interest.

[0205] As shown in the illustrated example, the localizer 522 may be an optical localizer including a localizer camera unit 527. The localizer camera unit 527 may include an outer casing housing one or more optical sensors 528 and a localizer controller 529 (FIG. 18). Each optical sensor 528 may be a separate charge-coupled device (CCD) and may be configured to detect optical signals at a particular wavelength, such as non-visible light (e.g., infrared), or at a particular frequency band. For example, without limitation, the optical sensor(s) 528 may consist of three one-dimensional CCDs or two two-dimensional CCDs. In alternative examples, the optical sensor(s) 528 may be in the form of a CMOS or other suitable sensor.

[0206] The localizer controller 529 ( FIG. 18 ) may be configured to operate the optical sensor(s) 528, such as at the direction of the navigation controller 524, and generate localizer data based on optically based signals received from the optical sensor(s) 528. The localizer data may indicate pixel locations of optical signals from the tracker 526 detected by the optical sensor(s) 528, and correspondingly, the position and / or orientation of the tracker 526 in a known coordinate system, such as a localizer coordinate system LCLZ specific to the localizer 522. The localizer controller 529 may be coupled to the navigation controller 524 and configured to communicate the localizer data to the navigation controller 524 for object tracking, as described in more detail below. Alternatively, the optical sensor(s) 528 and the navigation controller 524 may communicate directly.

[0207] The localizer 522 may be mounted on an adjustable arm to position the optical sensor(s) 528 in an ideally clear field of view of the tracker 526. The localizer 522 may be adjustable in at least one degree of freedom by rotating about a revolute joint, and may be adjustable in two or more degrees of freedom.

[0208] Each of the trackers 526 may be affixed to an object of interest within the surgical workspace. Generally, the object to which each tracker 526 is affixed may be rigid and inflexible such that the object cannot or is unlikely to move or deform relative to the tracker 526 during the surgical procedure. In other words, the spatial relationship between each tracker 526 and the object to which the tracker 526 is affixed may remain fixed during the surgical procedure, despite movement of the object during the surgical procedure. In this manner, in response to determining the position and / or orientation of the tracker 526 within the surgical workspace in the known coordinate system, the navigation controller 524 may infer the position of the object to which the tracker 526 is affixed in the known coordinate system based on the determined position and / or orientation of the tracker 526 and the fixed spatial relationship between the tracker 526 and the object.

[0209] Objects that may be tracked by the navigation system 14, and thus to which the tracker 526 may be affixed, may include the patient's anatomical structures of interest, as well as instruments, such as the ultrasound instrument 18 and the imaging system 15. The tracked anatomical structures may include hard tissue, such as bone, and soft tissue, such as skin. The tracked surgical instruments may include retractors, cutting tools, and waste management devices used during a surgical procedure.

[0210] 1, the trackers 526 may include a tool tracker 526A that tracks the position and / or orientation of the ultrasonic instrument 18 in a known coordinate system, a patient tracker 526B that tracks the position and / or orientation of the patient and target site TS in a known coordinate system, and an imaging system tracker 526C that tracks the position and / or orientation of at least a portion of the imaging system 15 in a known coordinate system. Additional trackers 526 are also contemplated, such as additional patient trackers and additional trackers for other medical and / or surgical tools.

[0211] The tool tracker 526A and the imaging system tracker 526C are each shown generally mounted to the gantry 516 of the ultrasound instrument 18 and imaging system 15, respectively. The patient tracker 526B may be rigidly affixed to different portions of the patient P's anatomy (e.g., on opposing sides of the ilium) via a mount assembly configured to releasably engage tissue (e.g., skin, bone). It will be appreciated that the trackers 526 may be rigidly affixed to different types of tracked objects (e.g., individual bones, tools, pointers, etc.) in a number of different ways.

[0212] Prior to the start of a surgical procedure, the navigation controller 524 can receive and store data indicative of a virtual model of the patient P's anatomy of interest, such as based on pre-operative images of the anatomy of interest that may be generated by the imaging system 15. The pre-operative images may be based on MRI, radiological, or computed tomography (CT) scans of the patient's anatomy and can be used to develop the virtual model of the anatomy of interest that is stored by the surgical navigation system 14. Each virtual model can include a three-dimensional model (e.g., point cloud, mesh, CAD) of at least a portion of the anatomy and / or can include a three-dimensional model or other indicator of at least a portion of the anatomy that forms at least a portion of the target volume of the patient tissue to be treated during the surgical procedure. In addition to, or instead of, taking pre-operative images, the treatment plan and virtual model of the anatomy of interest can be developed in the operating room from kinematic studies, bone tracking, and other methods. Additionally, prior to the surgical procedure, the navigation controller 524 can receive and store virtual models of the surgical instruments (e.g., the ultrasonic instrument 18) being used in the surgical procedure and other tracked objects of interest to the surgical procedure, such as a virtual model of the tracker 526.

[0213] Each virtual model of an object received and stored by the navigation controller 524 can define a three-dimensional coordinate system specific to the object and can indicate coordinates in the three-dimensional coordinate system that correspond to relative positions of features of the object. For example, the virtual model for a given tracker 526 can indicate coordinates in the tracker's 526-specific three-dimensional coordinate system that correspond to relative positions of markers of the tracker 526, described in more detail below. As a further example, the virtual model of a given surgical instrument can indicate coordinates in the surgical instrument's three-dimensional coordinate system that correspond to relative positions of features of a housing of the surgical instrument.

[0214] The navigation controller 524 may also receive and store data defining fixed spatial relationships between the trackers 526 and objects to which the trackers 526 are affixed, and the surgical plan. The spatial relationships may define the position and / or orientation of each tracker 526, or more specifically, the position and / or orientation of the markers of each tracker 526, relative to the object to which the tracker 526 is affixed, such as by referencing a virtual model of the object and the tracker 526. For example, the spatial relationship of a given tracker 526 may indicate where a coordinate system specific to the object affixed to the tracker 526 is located in a coordinate system specific to the tracker 526, and / or vice versa. The surgical plan may identify the patient's anatomy involved in the surgical procedure and the target volume of the patient's tissue to be treated in the surgical procedure, may identify the instruments being used in the surgical procedure, and may identify the planned trajectories of the instruments and the planned movements of the patient's anatomy during the surgical procedure.

[0215] The spatial relationship between the patient tracker 526B and the anatomical structure of the patient P to which it is attached can be determined by known alignment techniques, such as point-based alignment, in which a calibration tool including a calibration tracker is used to touch off a point across the anatomical structure being aligned. By monitoring the position and / or orientation of the calibration tracker relative to the position and / or orientation of the patient tracker 526B in a known coordinate system (e.g., the localizer coordinate system LCLZ) when the calibration tool is touched off from a point on the anatomical structure, the navigation controller 524 can be configured to determine the position and / or orientation of the anatomical structure relative to the patient tracker 526B based on the known spatial relationship between the touch point of the calibration tool and the calibration tracker. Additionally or alternatively, the navigation controller 524 may be configured to determine the spatial relationship of the patient tracker 526B to the anatomical structures of the patient P based on imaging data generated by the imaging system 15, which may indicate the position and / or orientation of the patient tracker 526B and the patient's anatomical structures in the same coordinate system, such as the coordinate system of the imaging system 15. Thus, the navigation controller 524 may be configured to determine the spatial relationship of the patient tracker 526B to the anatomical structures of the patient P based on this information in the imaging data.

[0216] During a surgical procedure, the optical sensor(s) 528 of the localizer 522 can detect optical signals, such as non-visible optical signals (e.g., infrared or ultraviolet) emitted from the tracker 526. In response to detecting these optical signals, the optical sensor(s) 528 can generate and communicate optical-based signals to the localizer controller 529, which can be configured to generate localization data from the optical-based signals indicative of pixel positions and, correspondingly, directions in which the detected optical signals were received by the optical sensor 528. The localizer controller 529 can be configured to communicate the localization data to the navigation controller 524, which can then be configured to determine tracker position and / or orientation data based on the localization data. The navigation controller 524 can then be configured to determine object position and / or orientation data indicative of the position and / or orientation of an object to which the tracker 526 is secured based on the determined tracker positions and / or orientations and a previously stored fixed spatial relationship between the tracker 526 and the object.

[0217] As shown in the example depicted in FIG. 1 , the navigation controller 524 and the localizer 522 may be supported on a mobile cart 530 that is movable relative to the base 514 of the imaging system 15. The mobile cart 530 may also support a user interface, generally indicated at 532, to facilitate operation of the navigation system 14 by displaying information to and / or receiving information from the surgeon or another user. The user interface 532 may be placed in communication with the navigation controller 524 and may include one or more output devices (e.g., monitors, indicators, display screens, speakers, etc.) that provide information to the surgeon. For example, as shown in the illustrated example, the output devices of the user interface 532 may include a display 534 adapted to be positioned outside a sterile field, including, but not limited to, a surgical workspace, and may include a display 536 adapted to be positioned inside the sterile field. The displays 534, 536 may be adjustably mounted to the mobile cart 530 and each may incorporate touch screen technology to receive user input from the surgeon or another user. Other input devices for the user interface 532 to receive user input may include, but are not limited to, a keyboard, a mouse, and / or a microphone to allow user input through voice recognition technology.

[0218] In response to determining object position and / or orientation data indicative of the position and / or orientation of the tracked objects in a known coordinate system, the navigation controller 524 may be configured to display a virtual representation of the relative position and / or orientation of the tracked objects to the surgeon or other user of the surgical system 10, such as with images and / or graphical representations of the anatomical structures of the patient P and the ultrasonic instrument 18 presented on the displays 534, 536. The navigation controller 524 may also be configured to display commands or request information from the surgeon or other user of the surgical system 10, utilizing the user interface 532.

[0219] 18, the trackers 526 affixed to objects within the surgical workspace may each include a known arrangement of markers 540 that emit optical signals detectable by the optical sensor(s) 528. In one example, the trackers 526 may be powered and thus may include an arrangement of powered markers 540, each configured to emit an optical signal in response to receiving an electrical current therethrough. As an example, the powered markers 540 may be implemented as light emitting diodes (LEDs) that transmit light, such as non-visible light (e.g., infrared or ultraviolet) detectable by the optical sensor(s) 528. These trackers 526 may be powered by an internal battery or may have leads that receive power via the navigation controller 524.

[0220] Each motorized tracker 526 may also include a tracker controller 542 connected to the motorized markers 540 of the tracker 526 and configured to control the rate and sequence in which the motorized markers 540 fire, such as at the direction of the navigation controller 524. Thus, the navigation controller 524 may be in data communication with the tracker controller 542, such as via a wireless or wired connection, to cause the motorized markers 540 of each tracker 526 to fire. The tracker controller 542 may cause the markers 540 of each motorized tracker 526 to fire at different rates and / or times to allow the navigation controller 524 to identify which marker 540 is firing at a given moment. In this manner, the navigation controller 524 may associate a given detected light signal with the marker 540 that was firing when the light signal was detected. Alternatively, the tracker controller 542 may cause the markers 540 to fire sequentially and / or simultaneously. In this case, each tracker 526 may include a unique known pattern of markers 540, and the navigation controller 524 may be configured to implement a marker assignment algorithm that may include matching optical signals detected by different optical sensors 528 that correspond to the same marker 540, triangulating the positions of the markers 540 corresponding to each set of matched optical signals, and comparing the triangulated positions to the known tracker marker pattern to determine which optical signals correspond to which markers 540 on the tracker 526.

[0221] Rather than being powered, one or more of the trackers 526 affixed to objects within the surgical workspace may be unpowered and therefore may include passive markers 540, such as reflectors that reflect light emitted from a light source proximate the surgical workspace (e.g., in the localizer 522). The reflected light may then be received and detected by the optical sensor(s) 528 and assigned to the markers 540 as described above.

[0222] The navigation system 14, or more specifically the localizer 522, may have other suitable components or structures not specifically described herein. Additionally, any of the techniques, methods, and / or components described herein with respect to the camera-based navigation system 14 shown throughout the figures may be implemented or provided for any of the other configurations of the navigation system 14 described herein. For example, the navigation system 14 may also be based on one or more of inertial tracking, ultrasonic tracking, image-based optical tracking (e.g., using markers defined by patterns, shapes, edges, etc. that can be monitored by a camera), or any combination thereof.

[0223] The navigation controller 524 may be configured to implement the functions, features, and processes of the navigation system 14 described herein. More specifically, similar to the ultrasound controller 112 and the tissue detection controller 302, the navigation controller 524 may include a processor 544 and a memory 546, each of which may include and / or be communicatively coupled to storage 548 configured similarly to that described above in connection with the ultrasound controller 112 and the tissue detection controller 302. For example, the processor 544 may similarly operate under the control of software programs 547 embodied by computer-executable instructions, such as a localization engine, a transformer, a navigator, a segmentation tool, and a tissue tracker, each of which are described in more detail below. The storage 548 may include data that facilitates the functions, features, and processes of the navigation controller 524 described herein, such as surgical planning data 550, virtual model data 552, and transformation data 554.

[0224] The localization engine software may be configured, at run time, to receive localization data from the localizer controller 529 and determine tracker position and / or orientation data indicative of the positions and / or orientations of the trackers 526 in a known coordinate system based on the localization data, such as by triangulating the positions of the markers 540 of each tracker 526 in the known coordinate system based on the localization data, as described above. The transformer software may be configured, at run time, to determine object position and / or orientation data indicative of the position and / or orientation of an object to which the trackers 526 are affixed, based on the tracker position and / or orientation data. For example, the stored transformation data 554 may indicate a fixed spatial position between the trackers 526 and the object to which the trackers 526 are affixed, which may be retrieved by the transformer and applied to the tracker position and / or orientation data to determine the object position and / or orientation data. The navigator software can be configured to provide navigation guidance based on the determined object position and / or orientation data, or more specifically, based on the tracked position and / or orientation of the object to which the tracker 526 is attached in a known coordinate system. As an example, the navigator can be configured to access a virtual model of the object from the virtual model data 552, and display and update a virtual boundary corresponding to the model on the user interface 532 at a position corresponding to the relative position of the object as indicated by the object position and / or orientation data.

[0225] The segmentation tool software, when executed, may be configured to generate one or more virtual boundaries corresponding to objects of interest in a known coordinate system, such as by applying a segmentation algorithm to the imaging data received from the imaging system 15. The segmentation algorithm may be configured to employ various techniques in machine vision to determine virtual boundary(s) associated with various objects and / or tissue types in the image represented by the imaging data. In some examples, the segmentation algorithm may be configured to receive as input a medical image and a type of procedure to be performed on the target site TS as indicated in the surgical planning data 550, apply one or more edge detection, clustering, and other segmentation algorithms calibrated based on the type of procedure to the medical image to identify boundaries between various objects and various types of tissue in the image, and generate corresponding virtual boundary(s) in an image coordinate system specific to the imaging system 15. Additionally or alternatively, a user may be able to manipulate a user interface 532 of the navigation system 14 (or a user interface 531 of the imaging system 15) to manually define such virtual boundary(s) in the image coordinate system and / or manipulate the virtual boundary(s) generated by the segmentation algorithm described above. The transformer may then be configured to determine the position and / or orientation of the virtual boundary(s) in a known coordinate system, such as the localizer coordinate system LCLZ, based on the tracker position and / or orientation data indicating the position of the imaging system tracker 526C in the known coordinate system and the transformation data 574 indicating a predetermined spatial relationship between the imaging system tracker 526C and a coordinate system specific to the imaging system 15.

[0226] The tissue tracker software, when executed, can be configured to correlate the tissue property(ies) determined by the ultrasonic tool system 12 and / or tissue detection system 13 with the tracked position and / or orientation of the ultrasonic instrument 18, or more specifically, the position of the working end 22 of the tip 20 relative to other tracked objects at the time the tissue property(ies) were determined. The tissue tracker software can also be configured to display at least one indicator in a known coordinate system that corresponds to the determined tissue property(ies) at the tracked position, and to verify that the determined tissue property matches the tissue being contacted by the ultrasonic instrument 18 as shown by the localization data and / or medical image. For example, the surgical planning data 550 can indicate various tissue properties associated with the generated virtual boundary(s), which may be pre-determined by a segmentation tool or the like, and / or input by the surgeon or other user via the user interface 532. Thus, the tissue tracker software may be configured to determine one or more characteristics of the tissue being contacted by the working end 22 of the tip 20 as indicated by the surgical planning data 550 based on the tracked position and / or orientation of the ultrasonic instrument 18 relative to the virtual boundary(s), and to compare the determined tissue characteristic(s) with the characteristic(s) determined by the ultrasonic tool system 12 and / or tissue detection system 13 to verify a match therebetween.

[0227] Figure 19 illustrates a processing architecture 560 that may be implemented by the surgical system 10 of Figure 1. As shown in the illustrated example, the processing architecture 560 may include a surgical control system 562, a user interface 563 communicatively coupled to the surgical control system 562, and one or more databases 572. The surgical control system 562 may also be operatively coupled to one or more of the ultrasonic instrument 18, the sample element 88, the localizer 522, and the imaging system 15.

[0228] The surgical control system 562 may generally be configured to adjust ultrasonic energy directed within the ultrasonic instrument 18, such as directing pulsed ultrasonic energy, based on the type of tissue being contacted by the working end 22 of the ultrasonic tip 20, and / or to verify the tissue detection and / or navigation routines described herein. In particular, the surgical control system 562 may include or be implemented by one or more of the ultrasonic controller 112 of the ultrasonic tool system 12, the navigation controller 524 of the surgical navigation system 14, the imaging controller 508 of the imaging system 15, and the tissue detection controller 302 of the tissue detection system 13. For example, each of one or more of the above controllers may be configured to implement one or more of the functions of the surgical control system 562 described herein, such as upon execution of corresponding software embodied by computer executable instructions by the controllers. In other words, the surgical control system 562 may be distributed across two or more of the above controllers and thus can cooperate with other components of the surgical system 10 to form a control system that implements the various functions, features, methods, and processes of the surgical system 10 described herein.

[0229] In some examples, the surgical control system 562 may include a software suite including multiple software programs or modules, each of which executes on at least one of the above controllers. For example, the surgical control system 562 may include an ultrasonic module 564, which may execute on at least the ultrasonic controller 112 and / or the navigation controller 524, and may be configured, upon execution, to adjust ultrasonic energy directed into the ultrasonic instrument 18 based on, for example, a determined type of tissue being contacted by the working end 22 of the ultrasonic tip 20. The surgical control system 562 may further include a navigation module 566, which may execute on at least the navigation controller 524, and may be configured, upon execution, to collect localization data indicative of a position and / or orientation of the working end 22 of the ultrasonic tip 20, and to generate tissue contact data indicative of a type of tissue being contacted by the working end 22 of the ultrasonic tip 20 based on a medical image of the patient. The surgical control system 562 may further include an imaging module 568, which may be executed by at least the imaging controller 508, and may be configured, upon execution, to generate imaging data defining a medical image of the patient, or more specifically, a target site on the patient. The surgical control system 562 may further include a tissue detection module 570, which may be executed by at least the tissue detection controller 302 and, upon execution, may be configured to determine the type of tissue being contacted by the working end 22 of the ultrasonic tip 20, as described in more detail below.

[0230] The one or more databases 572 of the processing architecture 560 may similarly be implemented by one or more of the console storage 118 of the ultrasonic tool system 12, the storage 318 of the tissue detection system 13, and the storage 548 of the surgical navigation system 14. For example, one or more of the above storages may each store at least a portion of the one or more databases 572. In other words, the one or more databases 572 may be distributed across two or more of the above storages. The one or more databases 572 may store data used by the surgical control system 562, or more specifically, by the modules of the surgical control system 562, to facilitate the functions, features, processes, and methods of the surgical control system 562 described herein. For example, the one or more databases 572 may store one or more of the pulse profile 140 and tissue type data 142 described above in connection with the ultrasonic tool system 12, the tissue map data 320 described above in connection with the tissue detection system 13, and the surgical planning data 550, the virtual model data 552, and the transformation data 554 described above in connection with the navigation system 14.

[0231] The user interface 563 can facilitate user operation of the surgical control system 562. More specifically, the user interface 563 can include one or more output components, such as a display, that present information from the surgical control system 562 to a user, and one or more inputs, such as a touch screen, that receive input from a user to the surgical control system 562. For example, the user interface 563 can include one or more of the foot pedal 76, the remote control 80, and the display 74 of the ultrasound tool system 12, the user interface 532 of the surgical navigation system 14, the user interface 531 of the imaging system 15, and the display 104 of the tissue detection system 13. In other words, the user interface 563 can be distributed across two or more of the above systems.

[0232] 20 illustrates a method 600 for operating the ultrasonic tool system 12, or more specifically the ultrasonic instrument 18, based on image data generated by the imaging system 15 and localization data generated by the localizer 522. The method 600 may be implemented by the surgical control system 562, or more specifically by the navigation controller 524 and / or the ultrasound controller 112.

[0233] At block 602, a medical image of a target site on a patient may be received, such as by the surgical control system 562. For example, the navigation controller 524 may receive image data from the imaging system 15 that defines an image of the patient including the target site. The target site may generally include areas of tissue that are targeted for ablation (e.g., tumor tissue areas) and areas of tissue that are not targeted for ablation (e.g., healthy tissue surrounding the tumor tissue) in accordance with the surgical plan.

[0234] At block 603, based on the medical image, one or more virtual boundaries and / or virtual regions associated with the region of tissue targeted for ablation may be generated, such as by the surgical control system 562, in a known coordinate system, such as the localizer coordinate system LCLZ. As described in more detail below, the surgical control system 562, or more specifically, as an example, the navigation controller 524, may be configured to track the orientation of the ultrasonic instrument 18 relative to the virtual boundary(s) and / or region(s) in the known coordinate system, and adjust ultrasonic energy directed within the ultrasonic instrument 18 based thereon.

[0235] For example, the surgical control system 562, or more specifically, as an example, the navigation controller 524, can be configured to generate an outer edge virtual boundary corresponding to a boundary or edge of tissue targeted for ablation, such that the virtual boundary is between or separates a region of tissue targeted for ablation (also referred to herein as "target tissue") from a region of tissue not targeted for ablation (also referred to herein as "non-target tissue"). In addition to the outer edge virtual boundary, the surgical control system 562 can be configured to generate one or more internal virtual boundaries within the target tissue region, such as at one or more threshold distances from the outer edge virtual boundary. The surgical control system 562 can also be configured to generate one or more virtual regions corresponding to areas or volumes defined between and / or adjacent to the virtual boundaries. As a non-limiting example, each virtual boundary and / or region can be realized by a line, plane, or surface mesh generated in a known coordinate system, such as the localizer coordinate system LCLZ.

[0236] In some implementations, the surgical control system 562, or more specifically, as an example, the navigation controller 524, may be configured to generate one or more virtual boundaries and / or regions by applying a segmentation algorithm to the received medical image, which may be configured to employ various techniques in machine vision to determine the virtual boundary(s) and / or region(s) of various tissue types within the image. In some examples, the segmentation algorithm may be configured to receive as input the medical image and the type of procedure to be performed on the target site as indicated in the surgical planning data 550, apply one or more edge detection, clustering, and other segmentation algorithms calibrated based on the type of procedure to the medical image to identify boundaries and / or regions between various types of tissue within the image, and generate corresponding virtual boundaries and / or regions within an image coordinate system associated with the medical image (e.g., a coordinate system specific to the imaging system 15). Segmentation algorithms specific to various procedure types may be generated from an artificial intelligence process. Additionally or alternatively, a user may be able to manipulate the user interface 556, or more specifically, the user interface 532 of the navigation system 14, which is coupled to the surgical control system 562, to manually define virtual boundaries and / or regions in the image coordinate system and / or manipulate the virtual boundaries and / or regions generated by the segmentation algorithm described above.

[0237] The surgical control system 562, or more specifically, the navigation controller 524, as an example, may then be configured to transform the virtual boundary and / or region defined in the image coordinate system associated with the image data to another known coordinate system, such as the localizer coordinate system LCLZ, to enable tracking of the pose of the ultrasonic instrument 18 relative to the boundary and / or region. For example, the navigation controller 524 may be configured to determine the pose of the imaging system tracker 526C in the localizer coordinate system LCLZ. Thereafter, based on previously stored transformation data 554 indicating a known spatial relationship between the image coordinate system and the coordinate system of the imaging system tracker 526C, the navigation controller 524 may be configured to transform the virtual boundary and / or region from the image coordinate system to the localizer coordinate system LCLZ.

[0238] At block 604, at least one ultrasonic energy profile, such as pulse profile 140 or constant energy profile 148, may be assigned to each of the virtual boundaries and / or regions. For example, the surgical control system 562, or more specifically, the navigation controller 524, as an example, may be configured to assign a pulse profile 140 to each virtual boundary and / or region such that when the working end 22 of the ultrasonic tip 20 reaches or crosses the virtual boundary and / or enters the region, as indicated by the positioning data generated by the localizer 522, the AC drive signal provided to the ultrasonic instrument 18 may be configured to direct pulsed ultrasonic energy in accordance with the pulse profile 140 assigned to the virtual boundary and / or region. In this manner, the ultrasonic instrument 18 may provide different levels of tissue selectivity and / or tactile feedback as the ultrasonic instrument 18 approaches various tissues, such as sensitive tissue or non-target tissue, near the target site TS. In some examples, the ultrasound controller 112 may be configured to determine available pulse profiles 140 from the console storage 118 or chip memory 174 as described above and communicate such pulse profiles 140 to the navigation controller 524 for assignment. Other configurations are contemplated in which the ultrasound controller 112 is configured to assign pulse profiles 140 to virtual boundary(s) and / or area(s).

[0239] In some embodiments, the surgical control system 562 can be configured such that when the working end 22 of the ultrasonic tip 20 reaches or crosses the virtual boundary in one direction, such as the direction in which the ultrasonic instrument 18 first reaches or crosses the virtual boundary, the AC drive signal supplied to the ultrasonic instrument 18 can be set to direct pulsed ultrasonic energy in accordance with the pulse profile 140 assigned to the virtual boundary. Conversely, when the working end 22 of the ultrasonic instrument 18 reaches or crosses the virtual boundary in the opposite direction, the AC drive signal supplied to the ultrasonic instrument 18 can be set to direct the ultrasonic energy that was directed within the ultrasonic instrument 18 prior to the initial contact with the virtual boundary. Alternatively, the surgical control system 562 may be configured to assign multiple ultrasonic energy profiles to each virtual boundary relative to the direction of movement such that when the ultrasonic instrument 18 reaches or crosses the virtual boundary in one direction, the AC drive signal supplied to the ultrasonic instrument 18 may be set to direct ultrasonic energy according to one assigned ultrasonic energy profile, such as pulse profile 140, and when the ultrasonic instrument 18 reaches or crosses the virtual boundary in the opposite direction, the AC drive signal supplied to the ultrasonic instrument 18 may be set to direct ultrasonic energy according to another assigned ultrasonic energy profile, such as pulse profile 140.

[0240] In some examples, the surgical control system 562, or more specifically, the navigation controller 524, as one example, may be configured to autonomously assign a pulse profile 140 to a virtual boundary(s) and / or region(s) based on the surgical procedure indicated by the surgical planning data 550 and / or the type of tissue identified in the medical image by the segmentation algorithm, etc. For virtual region(s) identified by the segmentation algorithm as containing soft tissue, the surgical control system 562 may be configured to restrict the assigned pulse profile 140 to the soft tissue pulse profile 144 associated with the soft tissue ablation mode of the ultrasonic tool system 12, and for virtual region(s) identified by the segmentation algorithm as containing hard tissue, the surgical control system 562 may be configured to restrict the assigned pulse profile 140 to the hard tissue pulse profile 146 associated with the hard tissue ablation mode of the ultrasonic tool system 12. Similarly, for a virtual boundary (or boundaries) identified by the segmentation algorithm as being within or adjacent to soft tissue, the surgical control system 562 may be configured to limit the assigned pulse profile 140 to the soft tissue pulse profile 144 associated with the soft tissue ablation mode of the ultrasonic tool system 12, and for a virtual boundary (or boundaries) identified by the segmentation algorithm as being within or adjacent to hard tissue, the surgical control system 562 may be configured to limit the assigned pulse profile 140 to the hard tissue pulse profile 146 associated with the hard tissue ablation mode of the ultrasonic tool system 12.

[0241] For a virtual boundary(s) identified by the segmentation algorithm as adjacent to both soft and hard tissue (e.g., representing a boundary between two types of tissue), the surgical control system 562 may be configured to restrict the assigned pulse profile 140 based on the surgical planning data 550, or more specifically, the planned trajectory of the ultrasonic instrument 18. For example, if the surgical planning data 550 indicates that the operating end 22 of the ultrasonic tip 20 should first reach or cross the virtual boundary in a direction toward the soft tissue side of the boundary, the surgical control system 562 may be configured to restrict the assigned pulse profile 140 to the soft tissue pulse profile 144 associated with the soft tissue ablation mode of the ultrasonic tool system 12. Conversely, if the surgical planning data 550 indicates that the operating end 22 of the ultrasonic tip 20 should first reach or cross the virtual boundary in a direction toward the hard tissue side of the boundary, the surgical control system 562 may be configured to restrict the assigned pulse profile 140 to the hard tissue pulse profile 146 associated with the hard tissue ablation mode of the ultrasonic tool system 12. Conversely, if multiple pulse profiles 140 can be assigned to each virtual boundary relative to the direction of movement, the surgical control system 562 can be configured to limit the assigned pulse profile 140 to the hard tissue pulse profile 146 associated with the hard tissue ablation mode of the ultrasonic tool system 12 in the direction toward the hard tissue side of the virtual boundary, and can be configured to limit the assigned pulse profile 140 to the soft tissue pulse profile 144 associated with the soft tissue ablation mode of the ultrasonic tool system 12 in the direction toward the soft tissue side of the virtual boundary.

[0242] Additionally or alternatively, for virtual boundary(s) and / or region(s) positioned at the edge or outside of the target tissue region according to the surgical plan, the surgical control system 562, or more specifically, by way of example, the navigation controller 524, may be configured to assign pulse profile(s) 140 that provide a relatively high level of tissue selectivity and / or tactile feedback (e.g., pulse control level 4 or 5), such that the AC drive signal can be set to direct ultrasonic energy according to such pulse profile(s) 140 when the working end 22 of the ultrasonic tip 20 moves to or across these virtual boundary(s) and / or enters these virtual region(s) from the target tissue region. Conversely, for virtual boundary(s) and / or region(s) positioned within the target tissue region according to the surgical planning data 550, the surgical control system 562 may be configured to assign an ultrasonic energy profile that provides a relatively low level of tissue selectivity and / or tactile feedback (e.g., pulse control level 3 or lower), such that the AC drive signal may be set to direct ultrasonic energy in accordance with such assigned ultrasonic energy profile as the ultrasonic instrument 18 moves across the interior virtual boundary(s) toward the edge of the target tissue region and / or enters the interior virtual region(s). In this manner, as the working end 22 moves from within the region closer to the edge of the target tissue region, the surgical control system 562, or more specifically, the ultrasonic controller 112, as an example, may be configured to direct pulsed ultrasonic energy within the ultrasonic instrument 18 that provides increased tissue selectivity and / or tactile feedback to the surgeon, thereby reducing ablation in adjacent non-target tissue regions and / or encouraging the surgeon to use special care when ablating tissue within the region.

[0243] In some instances, multiple virtual boundaries / regions may be defined within the target tissue region, in which case the surgical control system 562, or more specifically, as an example, the navigation controller 524, may be configured to assign a pulse profile 140 that provides increased tissue selectivity and / or tactile feedback to the virtual boundary(s) and / or region(s) as the distance between the virtual boundary(s) / region(s) from the edge of the target tissue region decreases.

[0244] Additionally or alternatively, the surgical control system 562, or more specifically, the navigation controller 524, as an example, may be configured to allow a user to manually assign pulse profiles 140 to various virtual boundary(s) and / or region(s) and / or adjust the assigned pulse profiles 140 set by the surgical control system 562, as described above, such as via a user interface 563, or more specifically, the user interface 532 of the navigation system 14, as an example. The surgical control system 562, or more specifically, the navigation controller 524, as an example, may also be configured to limit the pulse profiles 140 selectable by the user for a given boundary and / or region, such as based on the location of the virtual boundary and / or region relative to hard and soft tissue, as described above. For example, if a given boundary and / or region is located within a soft tissue region, the surgical control system 562 may be configured to limit the selectable pulse profiles 140 to those corresponding to a soft tissue mode, and if a given boundary and / or region is located within a hard tissue region, the surgical control system 562 can be configured to limit the selectable pulse profiles 140 to those corresponding to a hard tissue mode. Additionally or alternatively, if the surgical plan indicates that the procedure is to be limited to ablation of soft or hard tissue, the surgical control system 562 can be configured to limit the selectable pulse profiles 140 to those corresponding to a soft or hard tissue mode, as described above.

[0245] At block 606, a determination may be made, such as by the surgical control system 562, whether to activate the ultrasonic instrument 18. For example, a user may operate a user interface 563, or more specifically, for example, a foot pedal 76 of the ultrasonic tool system 12, to provide an instruction to the surgical control system 562, or more specifically, for example, the ultrasonic controller 112, to activate the ultrasonic instrument 18. In response to determining that the ultrasonic instrument 18 has been activated (the "Yes" branch of block 606), at block 608, ultrasonic energy may be directed into the ultrasonic instrument 18. More specifically, the surgical control system 562, or more specifically, for example, the ultrasonic controller 112, may be configured to direct a base ultrasonic energy into the ultrasonic instrument 18. The base ultrasonic energy may be set by the practitioner, such as via the display 74 of the control console 16. In some implementations, the base ultrasonic energy may correspond to a maximum ablation rate of the ultrasonic instrument 18 desired by the practitioner (e.g., a constant energy profile 148, a pulse profile 140 associated with a relatively low pulse control level).

[0246] At block 610, the orientation of the ultrasonic instrument 18 in a known coordinate system may be tracked, such as based on the localization data generated by the localizer 522. More specifically, the surgical control system 562, or more specifically, the navigation controller 524, as an example, may be configured to track the orientation of the working end 22 of the ultrasonic tip 20 of the ultrasonic instrument 18 relative to a virtual boundary(s) and / or region(s) in a known coordinate system, such as the localizer coordinate system LCLZ.

[0247] At block 612, ultrasonic energy, such as pulsed ultrasonic energy, may be directed within the ultrasonic instrument 18 based on the tracked pose of the ultrasonic instrument 18 and the virtual boundary(s) and / or region(s). More specifically, based on the tracked pose of the ultrasonic instrument 18 relative to the virtual boundary(s) and / or region(s), the surgical control system 562 may be configured to set an AC drive signal generated by a power source of the ultrasonic tool system 12 to direct pulsed ultrasonic energy within the tip 20 of the ultrasonic instrument 18, such as in accordance with the pulse profile(s) 140 assigned to the virtual boundary(s) and / or region(s). For example, based on the tracked pose of the ultrasonic instrument 18 relative to the virtual boundary(s) and / or region(s), the navigation controller 524 may be configured to determine an assigned pulse profile 140 to be induced within the ultrasonic instrument 18 and communicate a corresponding message to the ultrasonic controller 112, which may be configured to responsively set an AC drive signal generated by a power supply of the ultrasonic tool system 12 to induce pulsed ultrasonic energy at the tip 20 of the ultrasonic instrument 18 in accordance with the pulse profile 140.

[0248] In one example, a virtual boundary can be generated that corresponds to the outer edge of the target tissue region. Based on the tracked pose of the ultrasonic instrument 18 in a known coordinate system relative to the virtual boundary, the surgical control system 562, or more specifically, as an example, the navigation controller 524, can be configured to determine whether the working end 22 of the tip 20 reaches or crosses the outer edge virtual boundary from the target tissue region. If so, the surgical control system 562 can be configured to set an AC drive signal generated by the power supply of the ultrasonic tool system 12 to direct pulsed ultrasonic energy within the tip 20, for example, according to the pulse profile 140 assigned to the outer edge virtual boundary. For example, the navigation controller 524 can be configured to communicate a message indicative of the assigned pulse profile 140 to the ultrasonic controller 112, which can be configured to responsively set an AC drive signal generated by the power supply of the ultrasonic tool system 12 to direct pulsed ultrasonic energy within the tip 20 according to the pulse profile 140. Conversely, in response to determining that the working end 22 of the tip 20 is within the target tissue region, the surgical control system 562 can be configured to set an AC drive signal generated by the power source of the ultrasonic tool system 12 to direct an alternative ultrasonic energy (e.g., base ultrasonic energy) to the tip 20, such as continuous ultrasonic energy with a constant energy profile 148 or another, typically lower level, pulsed profile 140, as previously selected by the surgeon via the display 74 of the control console 16. In some examples, the directed base ultrasonic energy can provide less tissue selectivity and / or tactile feedback than any of the other assigned ultrasonic energy profiles, such as providing a higher ablation rate than the other assigned ultrasonic energy profiles.

[0249] As discussed above, in some examples, at least one virtual boundary may be generated within the target tissue region, the virtual boundary being assigned a different pulse profile 140 and spaced a threshold distance from the outer edge virtual boundary. Based on the tracked orientation of the ultrasonic instrument 18 relative to these virtual boundaries, including the outer edge virtual boundary, the surgical control system 562 may be configured to induce various levels of pulsed ultrasonic energy within the tip 20. For example, based on the tracked orientation of the ultrasonic instrument 18 in a known coordinate system relative to the virtual boundary, the surgical control system 562 may be configured to determine whether the working end 22 of the tip 20 reaches or crosses the outer edge virtual boundary from the target tissue region. If so, the surgical control system 562 may be configured to set an AC drive signal generated by the power source of the ultrasonic tool system 12 to induce pulsed ultrasonic energy within the tip 20, such as that corresponding to the pulse profile 140 assigned to the outer edge virtual boundary, which may be configured to provide a relatively high level of tissue selectivity and / or tactile feedback. For example, the navigation controller 524 may be configured to communicate a message indicating the assigned pulse profile 140 to the ultrasonic controller 112, which can be configured to set an AC drive signal generated by a power supply of the ultrasonic tool system 12 to direct pulsed ultrasonic energy within the tip 20 in accordance with the indicated pulse profile 140.

[0250] Further, based on the tracked pose of the ultrasonic instrument 18 in a known coordinate system relative to the virtual boundary, the surgical control system 562, or more specifically, the navigation controller 524, as an example, can be configured to determine whether the working end 22 of the tip 20 is within the target tissue region with the distance between the working end 22 of the tip 20 and the outer edge virtual boundary being less than a threshold distance that can correspond to a virtual boundary within the target tissue region. In other words, the surgical control system 562 can be configured to determine whether the working end 22 of the tip 20 is between the outer edge virtual boundary and an internal virtual boundary of the target tissue region. If so, the surgical control system 562 can be configured to set the AC drive signal generated by the power source to induce other pulsed ultrasonic energy within the tip, for example, according to the pulse profile 140 assigned to the internal virtual boundary, which can be a lower level pulse profile 140 relative to the pulse profile 140 assigned to the outer edge virtual boundary, and thus provide less tissue selectivity and / or tactile feedback.

[0251] In some examples, in response to determining that the working end 22 of the tip 20 is within the target tissue region, with the distance between the working end 22 of the tip 20 and the outer edge virtual boundary being greater than a threshold distance associated with the inner virtual boundary based on the tracked pose of the ultrasonic instrument 18 in a known coordinate system relative to the outer edge virtual boundary, the surgical control system 562 can be configured to set an AC drive signal generated by the power supply of the ultrasonic tool system 12 to induce base ultrasonic energy within the tip, which can be pre-defined by the surgeon via the control console 16 as described above.

[0252] As mentioned above, in some circumstances, multiple internal virtual boundaries may be generated, each at a different threshold distance from the outer edge virtual boundary. For example, without limitation, the internal virtual boundaries may include a first internal virtual boundary at a first threshold distance from the outer edge virtual boundary and a second internal virtual boundary at a second threshold distance from the outer edge virtual boundary, the second threshold distance being greater than the first threshold distance. In this case, based on the tracked pose of the ultrasonic instrument 18 in the known coordinate system relative to the virtual boundaries, the surgical control system 562 may be further configured to determine whether the working end 22 of the tip 20 is within the target tissue region with the distance between the working end 22 of the tip 20 and the outer edge virtual boundary being greater than the first threshold distance and less than the second threshold distance, corresponding to the working end 22 of the tip 20 being between the first internal virtual boundary and the second internal virtual boundary. If so, the surgical control system 562 may be configured to set the AC drive signal generated by the power source to induce pulsed ultrasonic energy within the tip 20 according to a pulse profile 140 assigned to the second interior virtual boundary. This pulsed ultrasonic energy may be different from that induced when the working end 22 of 16 is between the first interior virtual boundary and the outer edge virtual boundary, such as by being a pulse profile 140 that provides less tissue selectivity and / or tactile feedback (e.g., a lower level of pulse control).

[0253] Conversely, in response to determining that the working end 22 of the tip 20 is within the target tissue region with the distance between the working end 22 of the tip 20 and the outer edge virtual boundary greater than a second threshold distance associated with a second internal virtual boundary based on the tracked orientation of the ultrasonic instrument in a known coordinate system relative to the outer edge virtual boundary, the surgical control system 562 can be configured to set an AC drive signal generated by a power source of the ultrasonic tool system 12 to induce base ultrasonic energy within the tip 20.

[0254] At block 614, a determination may be made whether to shut down the ultrasonic instrument 18. For example, the surgeon may operate the user interface 556 to instruct the surgical control system 562 to shut down the ultrasonic instrument 18, such as by transitioning the foot pedal 76 to an off position. In response to determining not to shut down the ultrasonic instrument 18 (the "No" branch of block 614), the method 600 may return to block 610 to continue tracking the orientation of the ultrasonic instrument 18 in the known coordinate system and continue directing ultrasonic energy within the ultrasonic instrument 18 accordingly. In response to determining to shut down the ultrasonic instrument 18 (the "Yes" branch of block 614), the ultrasonic instrument 18 may be shut down at block 616. For example, the surgical control system 562, or more specifically the ultrasonic controller 112 as an example, may be configured to stop providing an AC drive signal to the ultrasonic instrument 18. The method 600 may then return to block 606 to monitor for restarting the ultrasonic instrument 18 as described above.

[0255] FIG. 21 illustrates a virtual boundary that may be generated for a surgical procedure involving the removal of a tumor tissue region 650 from adjacent healthy brain tissue 652. As shown in the pre-loaded surgical planning data 550, the procedure may involve at least two portions: a hard tissue cutting portion in which an ultrasonic instrument 18 is used to cut through the patient's skull 654, and a soft tissue ablation portion in which an ultrasonic instrument 18 is used to ablate tissue from the tumor tissue region 650. During the hard tissue cutting portion, the surgeon may utilize the hard tissue cutting tip 20 with the intent of cutting through the skull 654 while minimizing the cutting of healthy brain tissue 652. During the soft tissue ablation portion, the surgeon may utilize the soft tissue cutting tip 20 with the intent of removing tissue from the tumor tissue region 650 and minimizing the ablation of healthy brain tissue 652 adjacent to the tumor tissue region 650.

[0256] For the hard tissue cutting portion, FIG. 21 illustrates a defined outer edge virtual boundary 656 that corresponds to the inner wall of the skull 654 and corresponds to the end of the planned cauterization / cutting path of the ultrasonic instrument 18 through the skull 654. FIG. 21 further illustrates an inner virtual boundary 658 that may be defined a threshold distance away from the outer edge virtual boundary 656. A virtual region 660 may be defined between the inner virtual boundary 658 and the outer edge virtual boundary 656, and another virtual region 662 may be defined between the start of the planned cauterization / cutting path of the ultrasonic instrument 18 through the skull 654 and the inner virtual boundary 658. Each of the virtual boundaries 658, 656 may be associated with a different ultrasonic energy profile and / or each of the regions 660, 662 may be associated with a different ultrasonic energy profile such that the ultrasonic instrument 18 provides increasing tactile feedback as the working end 22 of the tip 20 approaches the end of the planned trajectory through the skull 654.

[0257] In response to receiving an instruction to activate the ultrasonic instrument 18, such as by the surgeon activating the foot pedal 76, the surgical control system 562 may be configured to verify that the tip 20 attached to the hand piece 24 is a bone-cutting tip, such as based on data stored in the tip memory 174, as described above. For example, the ultrasonic controller 112 may be configured to read data indicative of the type of tip 20 from the tip memory 174 and communicate a message indicative of the type of tip 20 to the navigation controller 524, which may then be configured to determine whether the appropriate tip 20 is attached based on the surgical planning data 550. If not, the surgical control system 562 may indicate an error, such as on the user interface 556, and may prevent the ultrasonic instrument 18 from operating. In response to determining that the bone-cutting tip 20 is secured to the hand piece 24, the surgical control system 562 may be configured to set an AC drive signal provided to the ultrasonic instrument 18 to direct ultrasonic energy, such as base ultrasonic energy, to the tip 20. For example, the navigation controller 524 can be configured to communicate a signal to the ultrasonic controller 112 that enables activation of the ultrasonic instrument 18. As previously described, the base ultrasonic energy can be continuous ultrasonic energy with a constant energy profile 148 or pulsed ultrasonic energy with a hard tissue pulse profile 146 that provides a relatively low tactile feedback (e.g., a relatively low pulse control level) previously selected by the surgeon. The surgical control system 562 can be configured to maintain the guidance of such ultrasonic energy within the ultrasonic instrument 18 while the working end 22 of the tip 20 is present within the region 662.

[0258] Based on the tracked pose of the ultrasonic instrument 18 in the known coordinate system, the surgical control system 562, or more specifically, the navigation controller 524, as an example, may be configured to determine whether the working end 22 of the tip 20 reaches or crosses the internal virtual boundary 658 into the virtual region 660. In other words, the surgical control system 562 may be configured to determine whether the distance between the outer edge virtual boundary 656 and the working end 22 of the tip 20 is less than or equal to a threshold distance associated with the internal virtual boundary 658. If so, the surgical control system 562 may be configured to set the AC drive signal to induce pulsed ultrasonic energy into the tip 20 of the ultrasonic instrument 18 according to a relatively high level of the hard tissue pulse profile 146 (e.g., pulse control level 4) associated with the internal virtual boundary 658 and / or region 660, etc. As a result of inducing such pulsed ultrasonic energy into the tip 20 of the ultrasonic instrument 18, the ultrasonic instrument 18 may begin to provide increased magnitude haptic feedback to alert the surgeon that the working end 22 of the tip 20 is approaching the inner wall of the skull 654. The surgeon can then take cues from the increased tactile feedback and reduce the force he or she applies to the ultrasonic instrument 18 and / or the speed at which the ultrasonic instrument 18 moves through the bone, which may help the surgeon maintain control and reduce cauterization of healthy adjacent tissue as the ultrasonic instrument 18 breaks through the inner wall of the skull 654.

[0259] Thereafter, based on the tracked pose of the ultrasonic instrument 18 in the known coordinate system, the surgical control system 562 can be configured to determine whether the working end 22 of the tip 20 reaches or crosses the outer edge virtual boundary 656, indicating that the working end 22 of the tip 20 has broken through the inner wall of the skull 654. If so, the surgical control system 562 can be configured to set the AC drive signal to induce pulsed ultrasonic energy within the tip 20 of the ultrasonic instrument 18 according to an even higher level of the hard tissue pulse profile 146 (e.g., pulse control level 5) associated with the outer edge virtual boundary 656, e.g., to increase the level of tactile feedback felt by the surgeon to indicate that the working end 22 of the tip has broken through. Alternatively, the surgical control system 562 can be configured to stop the ultrasonic instrument 18. The surgeon may then proceed to manually override the stop, such as by moving the ultrasonic instrument 18 backwards from its current position, in which case the surgical control system 562 can operate the ultrasonic instrument 18 based on the tracked pose of the working end 22 of the tip 20, as described above, or may proceed to manually override the stop, such as by returning the foot pedal 76 to its off position and then returning it to the active position, in which case the navigation controller 524 can enable the ultrasonic instrument 18 to operate according to the base ultrasonic energy, the hard tissue pulse profile 146 assigned to the internal virtual boundary 658 and / or region 660, or another hard tissue pulse profile 146 selected by the user.

[0260] Following completion of the bone cutting portion of the procedure, the surgeon may replace the bone cutting tip 20 with the soft tissue cutting tip 20 and then indicate that the soft tissue cutting portion is to begin, such as by depressing the foot pedal 76 and / or manipulating the user interface 532 of the navigation system 14. With respect to the soft tissue ablation portion of the procedure, FIG. 21 illustrates an outer edge virtual boundary 664 defined to correspond to the outer boundary of the tumor tissue region 650 and an inner virtual boundary 666 defined to correspond to a threshold distance away from the outer edge virtual boundary 664. A virtual region 668 may be defined between the inner virtual boundary 666 and the outer edge virtual boundary 664, and another virtual region 670 may be defined between the inner virtual boundary 666 and the entry point of the planned ablation / cutting path of the ultrasonic instrument 18 into the tumor tissue region 650. Each of the virtual boundaries 666, 664 may be associated with a different ultrasonic energy profile, such as a different soft tissue pulse profile 144, and / or each of the regions 668, 670 may be associated with a different ultrasonic energy profile, such as a different soft tissue pulse profile 144, such that the ultrasonic instrument 18 provides increased tactile feedback and / or tissue selectivity as the working end 22 of the tip 20 moves closer to the boundary between the tumor tissue region 650 and adjacent healthy brain tissue 652.

[0261] In response to receiving an instruction to activate the ultrasonic instrument 18 as described above, the surgical control system 562 can be configured to verify that the tip 20 attached to the hand piece 24 is a soft tissue ablation tip, such as based on data stored in the tip memory as described above. If not, the surgical control system 562 can be configured to indicate an error, such as on the user interface 556, and prevent the ultrasonic instrument 18 from operating. In response to determining that the soft tissue ablation tip 20 is secured to the hand piece 24, the surgical control system 562 can be configured to set an AC drive signal to direct base ultrasonic energy to the tip 20, such as continuous ultrasonic energy with a constant energy profile 148 or a relatively low level soft tissue pulse profile 144 previously selected by the user. The surgical control system 562 can be configured to maintain directing such base ablation ultrasonic energy while the working end 22 of the tip 20 is present within the region 670.

[0262] Based on the tracked pose of the ultrasonic instrument 18 in the known coordinate system, the surgical control system 562, or more specifically, the navigation controller 524, as an example, may be configured to determine whether the working end 22 of the tip 20 reaches or passes beyond the inner virtual boundary 666 into the region 668. In other words, the surgical control system 562 may be configured to determine whether the distance between the outer edge virtual boundary 664 and the working end 22 of the tip 20 is less than or equal to a threshold distance associated with the inner virtual boundary 666. If so, the surgical control system 562 may be configured to set the AC drive signal to direct pulsed ultrasonic energy within the tip 20 of the ultrasonic instrument 18 in accordance with a relatively high level of the soft tissue pulse profile 144 (e.g., pulse control levels 3, 4) associated with the inner virtual boundary 666 and / or the region 668, etc. For example, the navigation controller 524 may be configured to communicate a corresponding signal indicative of the soft tissue pulse profile 144 to the ultrasonic controller 112, which may be configured to responsively set the AC drive signal accordingly. As a result of directing such pulsed ultrasonic energy to the tip 20 of the ultrasonic instrument 18, the ultrasonic instrument 18 may provide increased tissue selectivity and / or increased magnitude tactile feedback to alert the surgeon that the working end 22 of the tip 20 is approaching the outer wall of the tumor tissue region 650. The surgeon may then take a cue from the tactile feedback and / or increased magnitude of tissue selectivity and proceed with caution, for example, by reducing the force the surgeon applies to the ultrasonic instrument 18 and / or the speed at which the ultrasonic instrument 18 moves through the tissue, which may help the surgeon maintain control and reduce ablation of healthy brain tissue 652 adjacent to the tumor tissue region 650.

[0263] Thereafter, based on the tracked pose of the ultrasonic instrument 18 in the known coordinate system, the surgical control system 562, or more specifically, as an example, the navigation controller 524, may be configured to determine whether the working end 22 of the tip 20 reaches or crosses the outer edge virtual boundary 656, indicating that the working end 22 of the tip 20 is adjacent to or in contact with healthy brain tissue 652. If so, the surgical control system 562, such as via corresponding communication between the navigation controller 524 and the ultrasound controller 112, may be configured to set the AC drive signal to direct pulsed ultrasonic energy to the tip 20 of the ultrasonic instrument 18 according to a higher level of the soft tissue pulse profile 144 (e.g., pulse control level 5) assigned to the outer edge virtual boundary 664, which may provide increased tissue selectivity and / or provide increased tactile feedback informing the surgeon of the location of the ultrasonic instrument 18. Alternatively, the surgical control system 562 may be configured to stop the ultrasonic instrument 18. The surgeon may then proceed to manually override the stop, such as by moving the ultrasonic instrument 18 backwards from its current position, in which case the surgical control system 562 may operate the ultrasonic instrument 18 based on the tracked pose of the working end 22 of the tip 20, as described above, or may proceed to manually override the stop, such as by returning the foot pedal 76 to its off position and then returning it to the active position, in which case the surgical control system 562 may enable the ultrasonic instrument 18 to operate according to the soft tissue pulse profile 144 associated with the base ultrasonic energy, the internal virtual boundary 666 and / or the region 668, or another soft tissue pulse profile 144 selected by the practitioner.

[0264] In some examples, the defined virtual boundary(s) and / or region(s) may also include an outer virtual boundary 672 outside the outer edge virtual boundary 664, such that it is at a defined distance from the outer edge virtual boundary 664, and may include a virtual region 673 defined between the outer edge virtual boundary 664 and the outer virtual boundary 672. The outer virtual boundary 672 and / or region 673 may correspond to a desired margin of ablation around the tumor tissue region 650, and thus define the general region of tissue targeted for ablation, including both the tumor tissue region 350 and the small amount of healthy brain tissue 652. In this case, the outer virtual boundary 672 may be assigned a soft tissue pulse profile 144 that provides increased tissue selectivity and / or tactile feedback (e.g., a higher pulse control level) than the soft tissue pulse profile 144 assigned to the outer edge virtual boundary 664 and / or virtual region 673. Thus, the surgical control system 562 may be configured to implement the assigned soft tissue pulse profile 144 such that the ultrasonic instrument 18 provides increased tissue selectivity and / or tactile feedback when the working end 22 of the tip 20 advances into region 673 and then impinges on the external virtual boundary 672. Alternatively, the surgical control system 562 may be configured to stop vibration when the working end 22 of the tip reaches the external virtual boundary 672.

[0265] FIG. 22 illustrates a virtual boundary and / or region that may be generated in a known coordinate system for a spinal fusion procedure. During such a procedure, an ultrasonic instrument 18 may be used to ablate tissue, including disc tissue 674 and cartilage endplate tissue 676, from between vertebral bodies 678 of the spine while minimizing contact with the spinal cord 680 and ablation of tissue from the vertebral bodies 678. To this end, FIG. 22 illustrates an outer edge virtual boundary 682 that corresponds to the outer boundary of tissue targeted for ablation, including disc tissue 674 and cartilage endplate tissue 676. FIG. 22 further illustrates an inner virtual boundary 684 positioned a threshold distance from a portion of the outer edge virtual boundary 682 adjacent the spinal cord 680, and a pair of inner virtual boundaries 686 that correspond to the boundary between the disc tissue 674 and the cartilage endplate tissue 676. A virtual region 688 may be defined between the internal virtual boundaries 684, 686, a virtual region 690 may be defined between the internal virtual boundary 684 and a portion of the outer edge virtual boundary 682 distal to the internal virtual boundary 684 and adjacent the spinal cord 680, and a virtual region 692 may be defined between each of the internal virtual boundaries 686 and a portion of the outer edge virtual boundary 682 distal to the internal virtual boundary 686 and adjacent one of the vertebral bodies 678. Each of the virtual boundaries 682, 684, 686 may be assigned a different ultrasonic energy profile and / or each of the regions 688, 690, 692 may be assigned a different ultrasonic energy profile, such as a different soft tissue pulse profile 144, such that the ultrasonic instrument 18 provides different levels of tissue selectivity and / or tactility as the working end 22 of the tip 20 of the ultrasonic instrument 18 moves through different portions of tissue targeted for ablation.

[0266] More specifically, in response to receiving an instruction to begin a surgical procedure, the surgical control system 562 may be configured to verify that the tip 20 attached to the hand piece 24 is a soft tissue ablation tip 20, for example, based on data stored in the chip memory 174 associated with the tip 20 as described above. If not, the surgical control system 562 may indicate an error, such as on the user interface 532, and may prevent the ultrasonic instrument 18 from operating. In response to determining that the soft tissue ablation tip 20 is secured to the hand piece 24, the surgical control system 562 may be configured to set the AC drive signal to induce base ultrasonic energy, such as continuous ultrasonic energy, into the tip 20 according to the constant energy profile 148 or the soft tissue pulse profile 144 previously selected by the user. The surgical control system 562 may be configured to continue inducing the base ablation ultrasonic energy while the working end 22 of the tip 20 is within the region 688.

[0267] Based on the tracked pose of the ultrasonic instrument 18 in the known coordinate system, the surgical control system 562, or more specifically, the navigation controller 524, as an example, may be configured to determine whether the working end 22 of the tip 20 reaches or passes beyond the internal virtual boundary 684 and enters the region 690. In other words, the surgical control system 562 may be configured to determine whether the distance between the portion of the outer edge virtual boundary 682 adjacent the spinal cord 680 and the working end 22 of the tip 20 is less than or equal to a threshold distance associated with the internal virtual boundary 684. If so, the surgical control system 562 may be configured to set the AC drive signal to direct pulsed ultrasonic energy within the tip 20 of the ultrasonic instrument 18 according to a soft tissue pulse profile 144 (e.g., pulse control level 4) associated with the internal virtual boundary 684 and / or region 690, which may differ from the base ultrasonic energy, such as by providing increased tissue selectivity and / or tactile feedback. The surgeon can then take cues from the tactile feedback and / or increased magnitude of tissue selectivity and reduce the force the surgeon applies to the ultrasonic instrument 18 and / or the speed at which the ultrasonic instrument 18 moves through the tissue, which can help the surgeon maintain control and reduce trauma to adjacent tissue that is not the target of the ablation and contact with the spinal cord 680.

[0268] Based on the tracked pose of the ultrasonic instrument 18 in the known coordinate system, the surgical control system 562 can also be configured to determine whether the working end 22 of the tip 20 reaches or crosses a portion of the outer edge virtual boundary 682 adjacent the spinal cord 680, indicating that the working end 22 of the tip 20 has broken through the distal end of the disc tissue 674. If so, the surgical control system 562 can be configured to set the AC drive signal to induce pulsed ultrasonic energy within the tip 20 of the ultrasonic instrument 18 according to a soft tissue pulse profile 144 (e.g., pulse control level 5) associated with the outer edge virtual boundary 682, which may differ from the previously derived soft tissue pulse profile 144 and may provide additional tissue selectivity and / or tactile feedback. Alternatively, the surgical control system 562 can be configured to stop the ultrasonic instrument 18. The surgeon may then proceed to manually override the stop, such as by moving the ultrasonic instrument 18 backwards from its current position, in which case the surgical control system 562 may operate the ultrasonic instrument 18 based on the tracked posture of the working end 22 of the tip 20, as described above, or may proceed to manually override the stop, such as by returning the foot pedal 76 to its off position and then back to its active position, in which case the surgical control system 562 may enable the ultrasonic instrument 18 to operate according to the base ultrasonic energy, the soft tissue pulse profile 144 assigned to the outer edge virtual boundary 682, or another pulse profile 140 selected by the user.

[0269] Based on the tracked pose of the ultrasonic instrument 18 in the known coordinate system, the surgical control system 562 can also be configured to determine whether the working end 22 of the tip 20 reaches or crosses one of the internal virtual boundaries 686 into region 692 from region 688. If so, the navigation controller 524 may be configured to set the AC drive signal to direct pulsed ultrasonic energy within the tip 20 of the ultrasonic instrument 18 according to a soft tissue pulse profile 144, etc., assigned to the internal virtual boundary 686 and / or region 692, which may differ from the base ultrasonic energy, by providing increased tissue selectivity and / or haptic feedback (e.g., pulse control level 4). The increased tissue selectivity and / or haptic feedback can alert the surgeon that the working end 22 of the tip 20 is contacting cartilage endplate tissue 676 near the vertebral body 678. The surgeon can take cues from the increased tissue selectivity and / or tactile feedback to reduce the force the surgeon applies to the ultrasonic instrument 18 and / or the speed at which the ultrasonic instrument 18 moves through the tissue, which can help the surgeon maintain control and reduce trauma to tissue that is not the target of the ablation.

[0270] Based on the tracked pose of the ultrasonic instrument 18 in the known coordinate system, the surgical control system 562 may be further configured to determine whether the working end 22 of the tip 20 reaches or crosses a portion of the outer edge virtual boundary 682 adjacent the vertebral body 678 from the region 692, indicating that the working end 22 of the tip 20 is in contact or near contact with the vertebral body 678. If so, the surgical control system 562 may be configured to set the AC drive signal to direct pulsed ultrasonic energy within the tip 20 of the ultrasonic instrument 18 according to a soft tissue pulse profile 144 assigned to the portion of the outer edge virtual boundary 682, which may differ from and provide more tissue selectivity and tactile feedback than the pulse profile 144 assigned to the inner virtual boundary 686 and / or region 692 (e.g., pulse control level 5), thereby alerting the surgeon to retract the working end 22 of the tip 20 from the current position. Alternatively, the navigation controller 524 may be configured to stop the ultrasonic instrument 18. The surgeon may then proceed to override the stop by moving the ultrasonic instrument 18 backwards from its current position, in which case the surgical control system 562 may operate the ultrasonic instrument 18 based on the tracked pose of the working end 22 of the tip 20 as described above, or may proceed to override the stop by moving the foot pedal 76 to its off position and then back to the active position, in which case the surgical control system 562 may enable the ultrasonic instrument 18 to operate according to the base ultrasonic energy, the soft tissue pulse profile 144 corresponding to the outer edge virtual boundary 682, or another soft tissue pulse profile 144 selected by the user.

[0271] 23 illustrates a method 700 for operating an ultrasonic instrument 18 to ablate tissue at a target site containing one or more types of tissue based on the tissue type detected by the tissue detection system 13. Method 700 may be implemented by the surgical control system 562, or more specifically, by the tissue detection controller 302 and the ultrasound controller 112, as one example.

[0272] At block 702, a type of tissue within or adjacent to the target site may be determined. For example, the practitioner may manipulate the user interface 556, or more specifically, the display 104 of the control console 86 of the tissue detection system 13, as an example, to select a pre-loaded tissue type, which may be stored as tissue map data 320 in the tissue detection console storage 318. Additionally or alternatively, the surgical control system 562, or more specifically, the tissue detection controller 302, as an example, may prompt the practitioner, such as via the display 104, to position a distal portion of the sample element 88 adjacent each type of tissue within or near the target site multiple times and / or in multiple locations.

[0273] In response to receiving an indication from the practitioner, such as via the display 104, that the sample element 88 is positioned adjacent a given type of tissue, the tissue detection controller 302 can be configured to illuminate the tissue adjacent a distal portion of the sample element 88 and collect the resulting fluorescence as described above. For each type of tissue detected during a surgical procedure, the surgical control system 562, or more specifically, as an example, the tissue detection controller 302, can then be configured to analyze the instances of fluorescence collected for that type of tissue to determine sample light intensities corresponding to each of one or more fluorochromes associated with that type of tissue. The surgical control system 562 can then be configured to generate tissue map data 320 for the type of tissue indicating minimum threshold values ​​for each of the one or more fluorochromes. For example, but not limited to, the minimum threshold value for each fluorochrome can be based on the lowest intensity sample of the fluorochrome, or the average of a certain number of lowest intensity samples of the fluorochrome. As an example, the tissue detection controller 302 can be configured to determine the minimum intensity threshold value for each fluorochrome by subtracting a predetermined buffer value from the lowest intensity value or average.

[0274] At block 704, an ultrasonic energy profile, such as a constant energy profile 148 or a pulse profile 140, may be assigned to each type of tissue. For example, the surgical control system 562, or more specifically, the tissue detection controller 302 or the ultrasonic controller 112, by way of example, may be configured to assign a pulse profile 140 to each type of tissue such that when the working end 22 of the tip 20 of the ultrasonic instrument 18 contacts that type of tissue, the AC drive signal provided to the ultrasonic instrument 18 is configured to direct pulsed ultrasonic energy in accordance with the pulse profile 140 assigned to that type of tissue. In this manner, the ultrasonic instrument 18 may provide different levels of tissue selectivity and / or tactile feedback as the ultrasonic instrument 18 contacts different tissue types, such as tissue types corresponding to or near susceptible or non-target tissue within or near the target site TS.

[0275] In some implementations, the surgical control system 562, or more specifically, the tissue detection controller 302 or the ultrasound controller 112, by way of example, can be configured to autonomously assign the pulse profile 140 based on the determined tissue type and data included in the tissue map data 320 and / or tissue type data 142 indicating which pulse profile 140 to assign to each of the various tissue types, etc. Additionally or alternatively, the surgical control system 562 can be configured to utilize localization data generated by the localizer 522 to assign the pulse profile 140, as described above. When assigning the pulse profile 140, the surgical control system 562 can also be configured to limit which pulse profiles 140 may be assigned to a given type of tissue, as described above, based on whether the tissue type is hard or soft tissue, etc. Additionally or alternatively, the surgical control system 562 can be configured to allow a user to modify the assigned pulse profile 140 or assign a pulse profile 140 via the user interface 556.

[0276] At block 706, a determination may be made whether to activate the ultrasonic instrument 18. For example, the practitioner may move the foot pedal 76 from an off position to an active position to provide an indication to activate the ultrasonic instrument. In response to determining to activate the ultrasonic instrument 18 (the "Yes" branch of block 706), at block 708, ultrasonic energy may be directed into the ultrasonic instrument 18, such as by the surgical control system 562. For example, the ultrasonic controller 112 may be configured to direct base ultrasonic energy into the ultrasonic instrument 18, which may correspond to an ultrasonic energy profile and power settings selected by the practitioner for the base ultrasonic energy, such as via the display 74 of the control console 16.

[0277] At block 710, the type of tissue being contacted by the operative end 22 of the tip 20 of the ultrasonic instrument 18 may be detected. For example, the surgical control system 562, or more specifically, by way of example, the tissue detection controller 302, may be configured to illuminate tissue with excitation light at one or more wavelengths via the excitation fiber 100 and collect the resulting fluorescent light via the excitation fiber 94, as described above. Based on the fluorescence, the surgical control system 562, or more specifically, by way of example, the tissue detection controller 302, may be configured to determine the type of tissue being contacted by the operative end 22 of the ultrasonic tip 20.

[0278] At block 712, ultrasonic energy, such as pulsed ultrasound, may be directed, such as by the surgical control system 562, into the ultrasonic instrument 18 based on the type of tissue detected. For example, assuming a given pulse profile 140 has been assigned to the type of tissue detected, the AC drive signal generated by the power supply of the ultrasonic tool system 12 may be set to direct pulsed ultrasonic energy into the tip according to the pulse profile 140. In one example, the tissue detection controller 302 may be configured to communicate a message indicative of the type of tissue detected to the ultrasonic controller 112, which may be configured to direct ultrasonic energy into the ultrasonic instrument 18 as described above based on the indicated type of tissue. Alternatively, the tissue detection controller 302 may be configured to determine the ultrasonic energy profile assigned to the type of tissue detected and communicate a message indicative thereof to the ultrasonic controller 112 for implementation.

[0279] An example of directing ultrasonic energy based on a detected tissue type may be described with reference to the tumor ablation procedure shown in FIG. 21. As previously discussed, the target site TS in the illustrated tumor ablation procedure may include, at least in part, a tumor tissue region 650 and adjacent healthy brain tissue 652. The tumor tissue region 650 may be marked by the surgical control system 562 as a tissue type targeted for ablation, and the adjacent healthy brain tissue 652 may be marked as a tissue type not targeted for ablation. These tissues may be detectable by the surgical control system 562, or more specifically, by the tissue detection system 13, as an example, and may each be assigned an ultrasonic energy profile. For example, tissue types targeted for ablation may be assigned a constant energy profile 148 or a soft tissue pulse profile 144 (e.g., pulse control level 1) that provide relatively low tissue selectivity and / or tactile feedback, and tissue types not targeted for ablation may be assigned a soft tissue pulse profile 144 that provides relatively high tissue selectivity and / or tactile feedback. In this manner, as the working end 22 moves from contact with the tumor tissue region 650 to adjacent healthy brain tissue 652, the ultrasonic instrument 18 can provide increased tissue selectivity, thereby minimizing undesired ablation of the healthy brain tissue 652. The ultrasonic instrument 18 can also provide increased tactile feedback that can be perceived by the surgeon to indicate to the surgeon that the working end 22 of the ultrasonic tip 20 is contacting healthy brain tissue 652. The surgeon can recognize such tactile feedback and / or increased tissue selectivity as a cue to proceed with increased caution.

[0280] In some examples, the target site TS may include a region of a tissue type where it may be desirable to direct ultrasonic energy that varies across the region. For example, it may be desirable to direct pulsed ultrasonic energy with increased tissue selectivity and / or tactile feedback to a region of a tissue type targeted for ablation adjacent to a region of a tissue type not targeted for ablation as the working end 22 of the ultrasonic tip 20 moves toward the periphery of the region. In this manner, as the working end 22 of the ultrasonic tip 20 moves closer to the edge of the region of a tissue type targeted for ablation, the ultrasonic instrument 18 may provide increased tissue selectivity and / or tactile feedback, which may minimize undesired ablation to a tissue type not targeted for ablation, and may signal to the practitioner the location of the working end 22 of the ultrasonic instrument 18 to proceed with caution.

[0281] 21 , it may be desirable to direct ultrasonic energy with relatively low tissue selectivity and / or tactile feedback to tumor tissue region 650 when the working end 22 of ultrasonic instrument 18 is in a central portion of tumor tissue region 650, such as region 670. Conversely, it may be desirable to direct ultrasonic energy with relatively high tissue selectivity and / or tactile feedback in a portion of tumor tissue region 650 that is adjacent to and between the central portion and another type of tissue, such as a peripheral portion of tumor tissue region 650 represented by region 668.

[0282] To this end, a central portion of the tumor tissue region 650 may be assigned an ultrasound energy profile having relatively low tissue selectivity and / or tactile feedback, such as a constant energy profile 148 or a relatively low level soft tissue pulse profile 144 (e.g., pulse control level 1). Conversely, a peripheral portion of the tumor tissue region 650 may be assigned a soft tissue pulse profile 144 providing greater tissue selectivity and / or tactile feedback, such as pulse control level 3 or pulse control level 4. Regions of healthy brain tissue 652 may be assigned a soft tissue pulse profile 144 providing greater tissue selectivity and / or tactile feedback, such as pulse control level 5.

[0283] Similarly, it may be desirable to induce ultrasonic energy with more tissue selectivity and / or tactile feedback to a region of healthy brain tissue 652 when the working end 22 of the ultrasonic instrument 18 is in the portion represented by region 673, i.e., the portion of healthy brain tissue 652 adjacent to or within a threshold distance of the tumor tissue region 650, and to further increase the tissue selectivity and / or tactile feedback of the directed ultrasonic energy as the working end 22 of the tip 20 moves further into the healthy brain tissue 652. Thus, portions of healthy brain tissue 652 closer and further from the tumor tissue region 650 may be assigned soft tissue pulse profiles 144 that provide increased tissue selectivity and / or tactile feedback from that induced in the tumor tissue region 650, such as pulse control levels 4 and 5, respectively.

[0284] In some embodiments, the surgical control system 562, or more specifically, by way of example, the tissue detection controller 302, can be configured to determine the location of the working end 22 of the ultrasound tip 20 relative to the edge of a region of a certain type of tissue based on the characteristics of the collected fluorescence. Specifically, for a region of a given type of tissue, the density of the tissue, and the density of the fluorescent dye within the tissue, can decrease toward the edge of the region, causing a change in the characteristics of the fluorescence emitted from the region as the distal portion of the sample element 88 moves from the center of the region toward the edge. In other words, as the distal portion of the sample element 88 moves from the center of the region to the edge, the intensity of the wavelength of fluorescence specific to the tissue type can vary according to a gradient, such as from greater intensity to lesser intensity.

[0285] Thus, to detect different portions of a region of a given type of tissue, the tissue type data 105 stored in the tissue detection console storage 318 can indicate both a minimum intensity threshold corresponding to the type of tissue and one or more other intensity thresholds greater than the minimum intensity threshold that distinguish different portions of the region of the type of tissue. For example, the one or more other intensity thresholds can include a peripheral intensity threshold, such that if the measured fluorescence intensity at the wavelength corresponding to the type of tissue is greater than the minimum intensity threshold and greater than the peripheral intensity threshold, the surgical control system 562, or more specifically, the tissue detection controller 302, can be configured to determine that the working end 22 of the ultrasonic tip 20 is within a central portion of the region. Alternatively, if the measured fluorescence intensity at the wavelength corresponding to the tissue type is greater than the minimum intensity threshold and less than or equal to the peripheral intensity threshold, the surgical control system 562, or more specifically, the tissue detection controller 302, can be configured to determine that the working end 22 of the ultrasonic tip 20 is within a peripheral portion of the region, which can correspond to a portion of the region that is within a threshold distance from an edge of the region. In some examples, the tissue type data 105 may also include one or more additional intensity thresholds greater than the peripheral intensity threshold and corresponding to additional bands between the peripheral and central portions of the region. Each of these bands may similarly be assigned a pulse profile 140 such that the tissue selectivity and / or tactile feedback provided by the ultrasonic instrument 18 increases as the working end 22 of the tip 20 moves through the band in a direction that follows the planned ablation path.

[0286] Additionally or alternatively, a surgical control system 562, such as, by way of example, the ultrasonic controller 112 or tissue detection controller 302, can be configured to utilize characteristics of the AC drive signal to determine the portion of a region of a given type of tissue in which the working end 22 of the ultrasonic tip 20 is located. Specifically, for a region of a given type of tissue, the density of the tissue may be decreased and, correspondingly, the mechanical impedance (e.g., stiffness) of the tissue may be decreased. As discussed above, the ultrasonic controller 112 may be configured to determine a load to be applied to the ultrasonic instrument 18, which may be a function of the stiffness of the tissue being contacted by the working end 22 of the tip 20 based on a load measurement. The load measurement is determined by the voltage v of the AC drive signal. S or based on the AC drive signal voltage v S and current i S Based on (e.g., the mechanical resistance R of the ultrasonic instrument 18 M The drive current may be determined based on characteristics of the AC drive signal, such as by calculating

[0287] The tissue type data 142 as stored in the ultrasound console storage 118 may include data indicative of various tissue types and ranges of load measurements corresponding to each of the tissue types, with different values ​​within the range being associated with different portions of the tissue type's region. For example, for a given tissue type, the tissue type data 142 may indicate a load threshold whereby a determined load measurement greater than the load threshold indicates that the working end 22 of the ultrasonic tip 20 is contacting a central portion of the region of the given type of tissue, and a determined load measurement less than the load threshold indicates that the working end 22 of the ultrasonic tip 20 is contacting a peripheral po...

Claims

1. An ultrasonic surgical tool system, An ultrasonic instrument comprising a suction pathway, an irrigation pathway, a tip, and a driver coupled to the tip, wherein the driver is configured to vibrate the tip in response to receiving an AC drive signal to cauterize the tissue of a target site; A power supply connected to the ultrasonic device and configured to generate the AC drive signal supplied to the driver of the ultrasonic device, A localizer configured to generate positional data indicating the orientation of the ultrasonic device in a known coordinate system, A control system coupled to the power supply and the localizer, The control system is equipped with, A medical image of the target site, including the tumor tissue region, is received. Based on the aforementioned medical image, a virtual boundary associated with the tumor tissue region is generated in the known coordinate system. Based on the position identification data, the orientation of the ultrasonic device in the known coordinate system is tracked. Based on the tracked orientation and virtual boundary of the ultrasonic device, the AC drive signal generated by the power supply is set to induce a first pulse ultrasonic energy within the chip. An ultrasonic surgical tool system configured as follows.

2. The control system is Based on the tracked orientation of the ultrasonic instrument in the known coordinate system with respect to the virtual boundary, it is determined whether the operating end of the tip reaches or crosses the virtual boundary from the tumor tissue region. In response to the determination that the operating end of the chip has reached or crossed the virtual boundary from the tumor tissue region, the AC drive signal generated by the power supply is set to induce the first pulsed ultrasonic energy within the chip. The ultrasonic surgical tool system according to claim 1, configured as described above.

3. The control system is Based on the tracked orientation of the ultrasonic instrument in the known coordinate system with respect to the virtual boundary, it is determined whether the operating end of the tip is within the tumor tissue area. In response to determining that the operating end of the chip is within the tumor tissue region, the AC drive signal generated by the power supply is set to induce continuous ultrasonic energy within the chip. An ultrasonic surgical tool system according to claim 1 or 2, configured as described above.

4. The control system is Based on the tracked orientation of the ultrasonic instrument in the known coordinate system with respect to the virtual boundary, it is determined whether the operating end of the tip is within the tumor tissue region when the distance between the operating end of the tip and the virtual boundary is less than a first threshold distance. When the distance between the operating end of the chip and the virtual boundary is smaller than the first threshold distance, and it is determined that the operating end of the chip is within the tumor tissue region, the AC drive signal generated by the power supply is set to induce the first pulsed ultrasonic energy into the chip. The ultrasonic surgical tool system according to claim 1, configured as described above.

5. The control system is Based on the tracked orientation of the ultrasonic instrument in the known coordinate system with respect to the virtual boundary, it is determined whether the operating end of the tip is within the tumor tissue region when the distance between the operating end of the tip and the virtual boundary is greater than the first threshold distance. When the distance between the operating end of the chip and the virtual boundary is greater than the first threshold distance, and it is determined that the operating end of the chip is within the tumor tissue region, the AC drive signal generated by the power supply is set to induce continuous ultrasonic energy into the chip. The ultrasonic surgical tool system according to claim 4, configured as described above.

6. The first pulse ultrasonic energy is generated based on a first modulated waveform, and the control system is Based on the tracked orientation of the ultrasonic instrument in the known coordinate system with respect to the virtual boundary, it is determined whether the operating end of the tip is within the tumor tissue region when the distance between the operating end of the tip and the virtual boundary is greater than the first threshold distance. The system is configured to set the AC drive signal generated by the power supply to induce a second pulsed ultrasonic energy within the chip in response to the determination that the operating end of the chip is within the tumor tissue region when the distance between the operating end of the chip and the virtual boundary is greater than the first threshold distance, and the second pulsed ultrasonic energy is generated based on a second modulation waveform different from the first modulation waveform. The ultrasonic surgical tool system according to claim 4.

7. The ultrasonic surgical tool system according to claim 6, wherein the first pulsed ultrasonic energy comprises a plurality of first ultrasonic energy pulses spaced apart by ultrasonic energy of a first minimum ultrasonic energy level, and the second pulsed ultrasonic energy comprises a plurality of second ultrasonic energy pulses spaced apart by ultrasonic energy of a second minimum ultrasonic energy level, and the first minimum ultrasonic energy level is less than the second minimum ultrasonic energy level.

8. The ultrasonic surgical tool system according to claim 7, wherein each of the first ultrasonic energy pulses and each of the second ultrasonic energy pulses reaches a peak at the maximum ultrasonic energy level set for the ultrasonic instrument.

9. The ultrasonic surgical tool system according to claim 8, wherein the first ultrasonic energy pulses are spaced by a first period of ultrasonic energy at a first minimum ultrasonic energy level, each peaking at the maximum ultrasonic energy level over a second period shorter than each of the first periods, and the second ultrasonic energy pulses are spaced by a third period of ultrasonic energy at a second minimum ultrasonic energy level, each peaking at the maximum ultrasonic energy level over a fourth period shorter than each of the third periods, with each of the first periods being longer than each of the third periods.

10. The ultrasonic surgical tool system according to any one of claims 6 to 9, wherein the first pulsed ultrasonic energy has a first pulse frequency, and the second pulsed ultrasonic energy has a second pulse frequency lower than the first pulse frequency.

11. The ultrasonic surgical tool system according to any one of claims 6 to 9, wherein the first pulsed ultrasonic energy has a first duty cycle, and the second pulsed ultrasonic energy has a second duty cycle that is greater than the first duty cycle.

12. The first pulse ultrasonic energy is generated based on a first modulated waveform, and the control system is Based on the tracked orientation of the ultrasonic device in the known coordinate system, it is determined whether the operating end of the tip reaches or crosses the virtual boundary from the tumor tissue region. The chip is configured to set the AC drive signal generated by the power supply in response to the determination that the operating end of the chip has reached or crossed the virtual boundary from the tumor tissue region, thereby inducing a third pulsed ultrasonic energy within the chip, wherein the third pulsed ultrasonic energy is generated based on a modulation waveform different from that of the first pulsed ultrasonic energy. An ultrasonic surgical tool system according to any one of claims 4 to 9.

13. The ultrasonic surgical tool system according to claim 12, wherein the third pulse ultrasonic energy comprises a plurality of third ultrasonic energy pulses spaced apart by an ultrasonic energy of a third minimum ultrasonic energy level, each peaking at a maximum ultrasonic energy level set for the ultrasonic instrument, the third minimum ultrasonic energy level being 5% or less of the maximum ultrasonic energy level.

14. The ultrasonic surgical tool system according to claim 13, wherein the first pulsed ultrasonic energy comprises a plurality of first ultrasonic energy pulses spaced apart by ultrasonic energy of a first minimum ultrasonic energy level greater than the third minimum ultrasonic energy level.

15. A system for controlling an ultrasonic instrument, comprising a chip and a driver coupled to the chip, The driver is configured to vibrate the chip in response to receiving an AC drive signal to cauterize the tissue at the target site. The aforementioned system, A medical image of the target site, including the tumor tissue region, is received. Receiving positional data indicating the orientation of the ultrasonic device in a known coordinate system, Based on the aforementioned medical image, a virtual boundary associated with the tumor tissue region is generated in the known coordinate system. Based on the position identification data, the orientation of the ultrasonic device in the known coordinate system is tracked. The power supply is instructed to generate the AC drive signal, which is supplied to the driver of the ultrasonic device, configured to induce a first pulse of ultrasonic energy within the chip, based on the tracked orientation and virtual boundary of the ultrasonic device. A system comprising one or more controllers configured in such a manner.

16. A computer program product for controlling an ultrasonic instrument, comprising a chip and a driver coupled to the chip, The driver is configured to vibrate the chip in response to receiving an AC drive signal to cauterize the tissue at the target site. When the aforementioned computer program product is executed by one or more processors, Receiving medical images of the target site including the tumor tissue region, Receiving positional data indicating the orientation of the ultrasonic device in a known coordinate system, Based on the medical image, generate a virtual boundary associated with the tumor tissue region in the known coordinate system. Based on the position identification data, the orientation of the ultrasonic device in the known coordinate system is tracked, and The power supply is instructed to generate the AC drive signal supplied to the driver of the ultrasonic device, which is configured to induce a first pulse of ultrasonic energy within the chip, based on the tracked orientation and virtual boundary of the ultrasonic device. A computer program product comprising at least one non-temporary computer-readable storage medium that stores instructions configured to cause one or more processors to perform the above.

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