Method and system for estimating the temperature of the end effector of an ultrasonic instrument

Abstract

This method is performed using a surgical system. The method determines the resonant frequency of the end effector of an ultrasonic instrument and determines whether the end effector of the ultrasonic instrument is heated or cooled. In response to determining that the end effector is heated, the method estimates the temperature of the end effector based on the output of a first temperature model having an input based on the resonant frequency. However, in response to determining that the end effector is cooled, the method estimates the temperature of the end effector based on the output of a second temperature model having an input based on the resonant frequency. The method then provides a notification based on the estimated temperature.

Description

[Technical Field]

[0001] Various embodiments of this disclosure generally relate to surgical systems, and more specifically to surgical systems for estimating the temperature of the end effector of an ultrasonic instrument. Other embodiments are also described. [Background technology]

[0002] Minimally invasive surgery (MIS), such as laparoscopic surgery, uses techniques aimed at reducing tissue damage during surgical procedures. Laparoscopic procedures typically require making numerous small incisions in the patient, for example, in their abdomen, through which multiple surgical tools, such as endoscopes, blades, grippers, and needles, are inserted into the patient. Gas is injected into the abdomen, causing it to inflate, thereby providing more space around the tips of the tools and making it easier for the surgeon to view and manipulate the tissue at the surgical site (through the endoscope). MIS can be performed faster and with less surgeon fatigue using a surgical robotic system in which the surgical tools are operably mounted on the distal end of a robotic arm, and a control system operates the arm and the mounted tools. The tip of the tool mimics the movement of a handheld user input device (UID) when the UID is being manipulated by the surgeon, by adjusting its position and orientation. The surgical robot system may have multiple surgical arms, one or more of which have an attached endoscope, and the other surgical arms have attached surgical instruments for performing specific surgical movements.

[0003] Control input from a user (e.g., a surgeon or other operator) is captured via one or more user input devices and then converted into control of the robotic system. For example, in response to a user command, a tool drive unit having one or more motors may actuate one or more degrees of freedom of the surgical tool when the surgical tool is positioned at the patient's surgical site. [Overview of the project] [Means for solving the problem]

[0004] Some surgical tools used in MIS procedures are ultrasonic instruments that use ultrasonic vibrations at their tip to rapidly generate heat for cutting and cauterizing tissue. The tip may include a blade that reaches a high temperature (e.g., above 300°C) during a "heating" cycle (or state) in which the blade oscillates in contact with a portion of the tissue, thereby generating heat through friction between the blade and the tissue during the oscillating motion. In particular, the system can be activated and the blade enters a heating cycle in response to user input from the operator, such as when the user presses a pedal or button. After reaching a high temperature, the blade may be used to cut a portion of the tissue while simultaneously sealing the remaining tissue. By performing multiple tasks (e.g., cutting for incision, cauterization, etc.), the use of the tool during laparoscopic surgery reduces the number of instruments and the frequency of instrument changes during the procedure.

[0005] After using an ultrasonic instrument in a heated state, the operator may stop providing user input (e.g., releasing a pedal or button), thereby stopping the instrument and allowing the blade to cool. However, during this time, the rate at which the blade cools remains unknown to the operator. As a result, the blade may remain at a high temperature (e.g., above the threshold temperature), and may be too hot to contact objects such as human tissue for a certain period until it cools down. In addition, this period can vary based on the last temperature of the blade during the instrument's heating cycle (e.g., at least 30 seconds). Therefore, it is inefficient during instrument use, the blade temperature between cycles cannot be monitored, and conventional systems cannot actively control the ultrasonic instrument to maintain the blade temperature below a desired temperature.

[0006] This disclosure provides a laparoscopic surgical system for efficiently estimating the temperature of an ultrasonic instrument during (and between) heating and cooling cycles of a blade using different temperature models. Specifically, the system can start an instrument in a heating cycle by providing power to oscillate the blade of the instrument used to incise tissue (e.g., in response to receiving user input from an operator, such as pressing a pedal or button). While the instrument is operating in this “high power” state, the system can use a heating temperature model to determine the blade temperature based on one or more characteristics of the instrument (e.g., input voltage, input current, resonant frequency, etc.). After the heating cycle is completed (e.g., after the operator releases the pedal), the system may enter a “low power” state (or cooling cycle), in which the ultrasonic instrument may draw less power (e.g., less current may be supplied) to cause less blade oscillation than while the instrument is in the high power state. While in this low-power state, the instrument may not draw enough power to generate frictional heat (for example, due to the blade vibrating over a lower range of motion than required to generate heat), but it may have enough power to determine one or more properties of the instrument, such as the blade's resonant frequency, which the system can use to estimate the temperature of the ultrasonic instrument using a cooling temperature model. As a result, the system may provide the operator with (e.g., continuous) temperature readings based on temperatures estimated using different models as the ultrasonic instrument transitions between heating and cooling cycles.

[0007] This disclosure provides a surgical system for estimating the temperature of an end effector, for example, to be displayed to the operator while the end effector is being used by the operator. Specifically, the system determines one or more characteristics of the end effector, such as the resonant frequency of the end effector, and determines whether the end effector is in a heated or cooled state. For example, the resonant frequency may be the frequency at which the end effector (e.g., the blades of the end effector) vibrates when (or as) the end effector enters a heated or cooled state. In response to determining that the end effector is in a heated state, the system may estimate the temperature of the end effector based on the output of a first (heated) temperature model having an input based on the resonant frequency. However, in response to determining that the end effector is in a cooled state, the system may estimate the temperature of the end effector based on the output of a second (cooled) temperature model having an input based on the resonant frequency. The system may present a notification based on the estimated temperature. For example, the system may display a pop-up notification on a display that includes the estimated temperature. As a result, the system can estimate the end effector temperature between different states in a consistent and efficient manner (for example, when an operator uses the end effector during a surgical procedure).

[0008] In one embodiment, the resonant frequency is a first resonant frequency at the start time when the end effector enters a heated or cooled state, the system determines the start temperature of the end effector at the start time, and determines a second resonant frequency of the end effector of the ultrasonic instrument at a time following the start time. In another embodiment, the temperature is estimated based on the start temperature, the first resonant frequency, and the second frequency. In some embodiments, estimating the temperature in response to determining that the end effector is in a heated state includes determining the temperature change of the end effector based on the difference between the first resonant frequency and the second frequency, and combining the temperature change with the start temperature.

[0009] In one embodiment, estimating the temperature in response to determining that the end effector is in a cooled state includes determining whether the end effector is air-cooled or contact-cooled; estimating the temperature of the end effector based on the output of a first cooling temperature model in response to determining that the end effector is air-cooled; and estimating the temperature of the end effector based on the output of a second cooling temperature model in response to determining that the end effector is contact-cooled. In another embodiment, the first cooling temperature model is a polynomial model, and the second cooling temperature model is an exponential model.

[0010] In one embodiment, the resonant frequency is a first resonant frequency, and estimating the temperature of the end effector based on the output of a second temperature model includes determining the model coefficients of the second temperature model based on the first resonant frequency, determining the second resonant frequency of the end effector of the ultrasonic instrument, and determining the temperature by applying the second resonant frequency and coefficients to the second temperature model. In another embodiment, the system determines the impedance of the end effector based on the input current of the ultrasonic instrument, and determines a corrected resonant frequency based on the impedance and the second resonant frequency. In some embodiments, determining the temperature of the end effector based on the output of a second temperature model includes applying the corrected resonant frequency as input to the second temperature model.

[0011] In one embodiment, the system determines the input current supplied to the ultrasonic instrument and determines whether the end effector is heated or cooled, which includes determining that the end effector is heated when the input current is greater than (or equal to) a current threshold, and determining that the end effector is cooled when the input current is less than a current threshold. In another embodiment, the system determines the impedance of the end effector based on the input current and determines that the end effector is cooled while in air in response to determining that the impedance is greater than a threshold, and determines that the end effector is cooled while in contact with an object in response to determining that the impedance is less than a threshold.

[0012] The above summary does not constitute an exhaustive list of all embodiments of the Disclosure. The Disclosure is disclosed in forms for carrying out the following inventions, including, in particular, those indicated in the claims, all of which may be practiced from all preferred combinations of the various embodiments summarized above. Such combinations may have specific advantages not specifically described in the above summary. [Brief explanation of the drawing]

[0013] Embodiments are shown as examples, not as limitations, in the drawings of the accompanying drawings, where similar reference numerals indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure mean at least one embodiment, not necessarily the same embodiment. Furthermore, for the sake of brevity and to reduce the total number of figures, a given figure may be used to illustrate features of two or more embodiments, and not all elements in the figure are necessarily required for a given embodiment. [Figure 1] An illustrative diagram of an example surgical system in an operating room is shown. [Figure 2] A diagram illustrating an ultrasonic device and generator according to one embodiment of this disclosure is shown. [Figure 3] Figure 2 shows the end effector of the ultrasonic instrument. [Figure 4] This is a block diagram of a surgical system according to one embodiment. [Figure 5] This is a flowchart of one embodiment of a process for estimating the temperature of the end effector of an ultrasonic device. [Figure 6] This is a flowchart of one embodiment of a process for estimating the temperature of the end effector of an ultrasonic instrument while the end effector is in a heated state. [Figure 7] This is a flowchart of one embodiment of a process for estimating the temperature of the end effector of an ultrasonic instrument while the end effector is in a cooling state. [Figure 8] This is a flowchart of another embodiment of the process for estimating the temperature of the end effector of an ultrasonic instrument while the end effector is in a cooling state. [Figure 9] This shows several stages of the surgical system's display, illustrating the actions performed by the end effector of the ultrasound instrument and indicating the temperature of the end effector. [Figure 10] This is a flowchart of another embodiment of the process for estimating the temperature of the end effector of an ultrasonic instrument. [Modes for carrying out the invention]

[0014] Some embodiments of this disclosure will be described with reference to the accompanying drawings. Wherever the shape, relative position, and other embodiments of the parts described in a given embodiment are not expressly defined, the scope of this disclosure is not limited to the parts shown, which are intended solely for illustrative purposes. Also, although numerous details are described, it will be understood that some embodiments may be carried out without these details. Where else, well-known circuits, structures, and art are not shown in detail so as not to obscure the understanding of this description. Furthermore, unless the meaning is clearly to the contrary, all scopes described herein are considered to include the endpoints of each scope.

[0015] Figure 1 shows a diagram of an exemplary (e.g., laparoscopic) surgical system (hereinafter sometimes referred to as "the System") 1 in an operating room. System 1 includes a user console 2, a control tower 3, and one or more surgical robotic arms 4 on a surgical robotic table (surgical table or surgical platform) 5. In one embodiment, the arms 4 may be mounted on a table or bed on which the patient lies, as shown in the example of Figure 1. In one embodiment, at least some of the arms 4 may be configured differently. For example, at least some of the arms may be mounted on the ceiling, side walls, or other suitable structural support such as a cart separate from the table. System 1 may incorporate any number of devices, tools, or accessories used to perform surgery on a patient 6. For example, System 1 may include one or more surgical tools (instruments) 7 used to perform surgery (surgical procedures). The surgical tools 7 may be end effectors for performing surgical procedures, attached to the distal end of the surgical arm 4.

[0016] Each surgical tool 7 may be operated manually, robotically, or both during surgery. For example, a surgical tool 7 may be a tool used to enter, view, or manipulate the internal anatomical structures of the patient 6. In one embodiment, the surgical tool 7 is a gripping device capable of grasping the patient's tissue. The surgical tool 7 may be manually controlled by a bedside operator 8, or robotically controlled via the actuated movement of a surgical robotic arm 4 to which the surgical tool is attached. For example, when manually controlled, the operator may manually control the tool by holding (e.g., physically) a portion of the tool (e.g., a handle), moving the handle, and / or pressing one or more input control units (e.g., buttons) on the tool (e.g., the handle of the tool). In another embodiment, when robotically controlled, the surgical system may operate the surgical tool based on user input (e.g., received via a user console 2, as described herein).

[0017] Generally, a remote operator 9, such as a surgeon or other operator, may use the user console 2 to remotely operate the arm 4 and / or attached surgical tools 7, for example, during remote operation. The user console 2 may be located in the same operating room as the rest of the system 1, as shown in Figure 1. However, in other environments, the user console 2 may be located in an adjacent or nearby room, or in a remote location, for example, in a different building, city, or country. The user console 2 may include one or more components, such as a seat 10, one or more foot-operated control units (or foot pedals) 13, one or more (handheld) user-input devices (UIDs) 14, and at least one display 15. The display is configured to show, for example, a view of the surgical site inside the patient 6. The display may be configured to display image data (e.g., still images and / or video). In one embodiment, the display may be any type of display, such as a liquid crystal display (LCD), a light-emitting diode (LED) display, or an organic LED (OLED) display. In some embodiments, the display may be a 3D immersive display for displaying 3D (surgical) presentations. For example, during a surgical procedure, one or more endoscope cameras may capture image data of the surgical site that the display presents to the user in 3D. In one embodiment, the 3D display may be an autostereoscopic display that provides 3D perception to the user without requiring special glasses. In another example, the 3D display may be a stereoscopic display that provides 3D perception using glasses (e.g., via an active shutter or polarization).

[0018] In another embodiment, the display 15 may be configured to display at least one graphical user interface (GUI) that can provide useful and / or interactive content, thereby assisting the user when performing a surgical procedure with one or more instruments in the surgical system 1. For example, some of the displayed content may include image data captured by one or more endoscope cameras, as described herein. In another embodiment, the GUI may include selectable UI items that, when operated by the user, cause the system to perform one or more actions. For example, the GUI may include UI items as interactive content for switching control between robotic arms. In one embodiment, the system may include input devices such as a keyboard or mouse to interact with the GUI. In another embodiment, the user can interact with the GUI using a UID 14. For example, the user may manipulate the UID (e.g., using a cursor) to navigate through the GUI, and may manipulate the UID (e.g., select a control or button) by hovering the cursor over a UI item to make a selection. In some embodiments, the display may be a touch-sensitive display screen. In this case, the user may make selections by navigating and selecting through touching the display. In some embodiments, UI items can be navigated and / or selected using any method.

[0019] As shown in the figure, the remote operator 9 sits in the seat 10 and looks at the user display 15 while operating the foot-operated control unit 13 and the handheld UID 14 to remotely control one or more of the arm 4 and the surgical tools 7 (attached to the distal end of the arm 4).

[0020] In some variations, the bedside operator 8 may also operate the system 1 in "bed-facing" mode, in which the bedside operator 8 (user) is present beside the patient 6 and simultaneously operates a robot-driven tool (an end effector attached to arm 4) with a handheld UID 14 held in one hand, for example, while operating a manual laparoscopic tool. For example, the bedside operator's left hand may be operating the handheld UID to control robotic components, while the bedside operator's right hand may be operating a manual laparoscopic tool. Thus, in these variations, the bedside operator 8 may perform both robot-assisted minimally invasive surgery and manual laparoscopic surgery on the patient 6.

[0021] During an exemplary procedure (surgery), patient 6 is sterile, prepared, and covered to achieve anesthesia. Initial access to the surgical site may be performed manually, during which the arms of system 1 are in a retracted or retracted configuration (thereby facilitating access to the surgical site). Once access is complete, initial positioning or preparation of system 1, including its arms 4, may be performed. The surgery then progresses by a remote operator 9 on the user console 2, who uses a foot-operated control unit 13 and UID 14 to operate various end effectors and possibly an imaging system. Manual assistance may also be provided at the procedure bed or table by bedside personnel wearing sterile gowns, e.g., bedside operator 8, who may perform tasks such as retracting tissue, performing manual repositioning, and changing one or more tools of the robotic arms 4. Non-sterile personnel may also be present to assist the remote operator 9 on the user console 2. Once the procedure or surgery is complete, System 1 and User Console 2 may be configured or set to facilitate postoperative procedures such as cleaning or sterilization and inputting or printing medical records via User Console 2.

[0022] In one embodiment, a remote operator 9 holds and moves a UID 14, providing input commands to drive (move) one or more robotic arm actuators 17 (or drive mechanisms) within System 1 for remote operation. The UID 14 may be communicably coupled to the rest of System 1, for example, via a console computer system 16 (or host). The UID 14 may generate spatial state signals corresponding to the movement of the UID 14, for example, the position and orientation of the UID's handheld housing, but the spatial state signals may also be input signals for controlling the movement of the robotic arm actuators 17. System 1 may use control signals derived from the spatial state signals to control the proportional movement of the actuators 17. In one embodiment, a console processor in the console computer system 16 receives the spatial state signals and generates corresponding control signals. Based on these control signals, which control how the actuators 17 are energized to drive segments or links of the arm 4, the movement of a corresponding surgical tool attached to the arm may mimic the movement of the UID 14. Similarly, the interaction between the remote operator 9 and the UID 14 can generate a gripping control signal, for example, to close the jaws of the gripping instrument of the surgical tool 7 to grasp the patient's tissue 6.

[0023] System 1 may include multiple UIDs 14, in which case a control signal is generated for each UID to control the actuator and surgical tool (end effector) of each arm 4. For example, a remote operator 9 may move a first UID 14 to control the movement of an actuator 17 in the left robotic arm, in which case the actuator responds by operating the couplings, gears, etc., within the arm 4. Similarly, the movement of a second UID 14 by the remote operator 9 controls the movement of another actuator 17, which in turn drives its other couplings, gears, etc., in System 1. System 1 may include a right arm 4 on the right side of a patient fixed to a bed or table, and a left arm 4 on the left side of the patient. The actuator 17 may include one or more motors, which are controlled to drive the rotation of the couplings of the arm 4 to change, for example, the orientation of the endoscope or gripping device of the surgical tool 7 attached to the arm relative to the patient. The movement of multiple actuators 17 within the same arm 4 may be controlled by spatial state signals generated from a particular UID 14. UID14 can also control the movement of each surgical tool gripper. For example, each UID14 can generate a gripping signal to control the movement of an actuator, such as a linear actuator, that opens and closes the jaws of the gripper at the distal end of the surgical tool 7 to grasp tissue within the patient 6.

[0024] In some embodiments, communication between the surgical robot table 5 and the user console 2 may be via a control tower 3 that can translate user commands received from the user console 2 (more specifically from the console computer system 16) into robot control commands to be sent to the arm 4 on the surgical table 5. The control tower 3 may also transmit status and feedback from the surgical table 5 to the user console 2. The communication connection between the surgical table 5, the user console 2, and the control tower 3 may be via wired (e.g., optical fiber) and / or wireless links using any preferred wireless data communication protocol, such as the Bluetooth protocol. Any wired connection may be optionally built into the floor and / or walls or ceiling of the operating room. System 1 may provide video output to one or more displays, including an in-operating room display and a remote display accessible via the Internet or other network. The video output or feed may also be encrypted to ensure privacy, and all or part of the video output may be stored on a server or electronic medical record system.

[0025] Figure 2 shows a diagram of an ultrasonic instrument 20 and a generator 25 according to one embodiment of the present disclosure. As shown, the ultrasonic instrument may be a handheld laparoscopic instrument configured to perform ultrasonic surgical procedures or tasks such as cutting, tissue sealing (cautery) based on manual movement / operation of the instrument (e.g., the handle 21) by an operator (e.g., a surgeon). For example, during a laparoscopic (or endoscopic) surgical procedure, a small incision may be made in the patient to form an opening (or port), and through the opening, the ultrasonic instrument may be inserted into the patient's cavity (e.g., using gas to ventilate the cavity), where the operator may use an end effector to manipulate tissue and perform surgical procedures (e.g., cutting and / or cautery). The ultrasonic instrument is coupled (e.g., via a cable) to a generator (as shown) which enables the ultrasonic instrument to operate in one or more power states, as described herein.

[0026] According to an embodiment of this technology, the ultrasonic instrument includes a handle (e.g., including a tool drive unit) 21, a shaft (or cannula) 22, and an end effector 23 that can be loaded into the cannula (e.g., can be coupled to the shaft of the instrument).

[0027] The handle 21 may be positioned to be held by an operator, allowing the operator to manipulate the ultrasonic instrument (e.g., its end effector 23) during a surgical procedure. In one embodiment, the handle may include one or more inputs (e.g., a trigger, one or more buttons, etc.) that enable the operator to control the ultrasonic instrument. For example, the instrument may include a trigger that generates a control signal that enables the user to control the end effector of the instrument (and / or control a part of the surgical system) when pulled by one or more fingers of the user while being grasped. In particular, the trigger may be positioned to manipulate the end effector (e.g., by adjusting the position of the hinged arm 31 shown in Figure 3). In another embodiment, the handle may include one or more inputs for changing the power state of the instrument. Further description of the power states of the instrument is provided herein.

[0028] As described herein, the handle may include a tool drive unit (not shown) which can be arranged to drive the end effector 23 of the ultrasonic instrument. Specifically, the tool drive unit may include a (e.g., linear) motor or actuator which can be arranged to vibrate (or oscillate) (e.g.) the end effector (e.g., its blade) at one or more frequencies (e.g., very high (ultrasonic) frequencies and / or low frequencies). In some embodiments, the tool drive unit is configured to vibrate the end effector such that a portion of the end effector (e.g., the blade) moves back and forth along one or more axes. Specifically, the tool drive unit can vibrate the end effector over one or more ranges of motion, and over each range of motion, the end effector (e.g., its blade) can be displaced by (e.g., different) distances from its starting (or beginning) position. Further description of how the end effector vibrates is provided herein. In another embodiment, the tool drive unit may include an ultrasonic transducer configured to vibrate the end effector according to an input voltage / input current (applied, for example, by the generator 25).

[0029] As described above, the ultrasonic instrument may include an end effector 23 and a handle 21 (which may include a tool drive unit). Specifically, the instrument includes a gripping part 21, a shaft 22 which can be connected to the distal end of the handle, and an end effector 23 which can be connected to the distal end of the shaft. In this case, the ultrasonic instrument referred to herein may be an end effector which can be coupled (for example) to the handle (the tool drive unit via the shaft 22). In one embodiment, the ultrasonic instrument (e.g., its end effector) may be separate from the handle (and may be detachably coupled). In some embodiments, the shaft receives and guides the blade (e.g., its shaft) for coupling with the instrument.

[0030] As described herein, the surgical system 1 includes an ultrasonic instrument 20 configured to generate heat based on the vibration of its end effector 23. In another embodiment, the instrument may be any type of energy tool (e.g., an endoscope, laparoscope, etc.) designed to generate heat.

[0031] As previously described, the ultrasound instrument 20 may be a handheld laparoscopic instrument that can be manually held and operated by an operator. In another embodiment, the instrument may be part of a surgical robotic arm. Specifically, the ultrasound instrument may be coupled to a robotic arm and powered by a generator, as described herein. For example, the ultrasound instrument may be coupled to the distal end of a robotic arm (e.g., arm 4 in Figure 1), and the robotic arm includes several components that enable the robotic arm to be controlled by an operator. For example, the surgical robotic arm 4 may include a plurality of links and a plurality of actuation joint modules for acting the plurality of links toward each other. The joint modules may include various types such as pitch joints or roll joints, which may substantially restrict the movement of adjacent links toward others around a particular axis. The plurality of joint modules of the robotic arm 4 may be actuated to position and orient the ultrasound instrument for robotic surgery. In one embodiment, the ultrasound instrument may be coupled to the distal end via a tool drive unit positioned to actuate the end effector 23 of the instrument.

[0032] When an ultrasonic instrument is coupled to a robotic arm, the movement and operation of the ultrasonic instrument may be performed via one or more user control units (e.g., UID, foot pedal, etc.) coupled to the surgical system. For example, the UID may be configured to open and close the gripping device (of the end effector 23) of the ultrasonic instrument, and / or to adjust the spatial position (in space) of the gripping device based on user input (e.g., the position of the UID).

[0033] Referring to Figure 3, this figure shows the end effector 23 of the ultrasonic instrument of Figure 2. Specifically, this figure shows that the end effector is a gripping device (or gripping instrument) comprising a blade (or tip) 30 as one jaw and a hinge arm (or jaw) 31 rotatably coupled to a joint (or robotic wrist) 32 coupled to the distal end of the shaft. In another embodiment, the end effector 23 (e.g., its joint 32) may be part of a portion of the shaft 22 (the distal end). In another embodiment, the joint 32 may be part of the blade 30. In one embodiment, the gripping device (or part of the gripping device) is received through the shaft 22. For example, the blade may be received (and extend) through the shaft and is positioned at (or toward) the proximal end of the shaft to be coupled to a tool drive (e.g., of a handle 21).

[0034] The hinged arm 31 may be rotatably coupled to the shaft 22 (at the joint 32) and may be positioned to rotate about a rotational (Z) axis (for example, in the Z direction). Specifically, the gripper may be positioned to open and close based on the rotational position of the hinged arm about the rotational axis of the joint with respect to the blade (and / or shaft). For example, the gripper is positioned to open (or be in the open position) when the hinged arm is rotated away from the blade (for example, by a threshold distance). While in this position, the end effector may be oriented so that an object, such as tissue, can be positioned between the blade and the hinged arm (for example, by moving the end effector around the object). The gripper may also be closed (or be in the closed position) when the hinged arm rotates toward the blade (for example, within a threshold distance), thereby allowing the gripper to grip an object between the blade and the hinged arm. As described herein, the hinged arm may be positioned to apply pressure to the grasped object (e.g., compressing the object between the jaws) in order to grasp the object and / or perform an incision on the object. In another embodiment, the hinged arm 31 may be rotatably coupled to the blade (or a portion thereof). In one embodiment, the blade 30 and the hinged arm may be received through a shaft such that the arm (and / or blade) is coupled to another shaft through which the shaft 22 passes.

[0035] As described herein, the blade 30 may be the jaw of a gripping device. In particular, the blade is a jaw that cannot rotate relative to the end effector (for example, about the Z-axis). The blade may be arranged to vibrate along its longitudinal (Y) axis (in the Y direction) to generate heat while the ultrasonic instrument is in a high-power (or heated) state (or mode). In particular, the blade may be driven (for example, by the tool drive unit of the handle 21) to move back and forth (for example, linearly) along the longitudinal axis of the end effector (and through the cannula as described herein) to repeatedly displace the blade 30 at a frequency (for example, a constant frequency). Specifically, the blade may vibrate (for example, reciprocate) over a range of motion (or displacement), in which case the blade moves a certain distance from the starting position (for example, forward or away from the end effector) and then returns by that distance. In one embodiment, the range of motion may be the distance the blade moves from the starting position to the extended position. In another embodiment, the range of motion may be the distance the blade moves back and forth.

[0036] As described herein, the blade may generate frictional heat while vibrating in contact with the object. Specifically, the blade may be in contact with the tissue and vibrate in contact with the tissue while the gripper compresses the tissue between the two jaws 30 and 31. When the blade vibrates, the end effector may cut and / or cauterize the tissue as described herein. In one embodiment, the blade may vibrate differently (e.g., over different ranges of motion) based on the power state of the ultrasonic instrument (e.g., how much power is supplied). Further descriptions of the vibrating blade and power state of the ultrasonic instrument are provided herein.

[0037] As described above, the end effector 23 may be a gripping device. In another embodiment, the end effector may be any type of tool that can be operated by an ultrasonic instrument (e.g., its handle 21). For example, the end effector may be an endoscope, a stapler, or the like.

[0038] Returning to Figure 2, the generator 25 is configured to control and supply power to the ultrasonic instrument in order to control (e.g., heat) the end effector 23 while the instrument is coupled to the generator and in use by the operator (e.g., during laparoscopic surgery to manipulate tissue and / or perform one or more surgical tasks on the tissue, e.g., to cut and seal blood vessels and / or cut, grasp and incise tissue). In particular, the generator may supply power to the ultrasonic instrument so that the surgical system 1 (e.g., its ultrasonic instrument) can operate in one or more power states. For example, the generator may supply power to the instrument so that the ultrasonic instrument is in a “high power” state (or “heated state”), in which case the instrument draws power (or current) from the generator (e.g., at a specific voltage) to generate heat in the end effector 23. For example, the generator may supply (e.g., a first) current (or input current) to the handle of the ultrasonic instrument (e.g., the tool drive of the handle), and the ultrasonic instrument may use this current to drive the blade 30 to vibrate (or oscillate) over the (first) range of motion (and at a specific frequency). As described herein, frictional heat may be generated by the end effector while the blade of the end effector is pressed against an object such as tissue and vibrates over this range of motion, and may be used to cut and / or cauterize the object.

[0039] In another embodiment, the ultrasonic instrument may be configured to operate in a “low power” state (or “cooled state”), in which case the ultrasonic instrument no longer draws (sufficient or much) of power provided by the generator to heat the end effector while the instrument was in a high power state. Specifically, while in this state, the generator may be configured to provide the ultrasonic instrument with less power than the power provided by the generator while the instrument was in a high power state, so that the end effector does not generate heat (e.g., if in contact with an object). In particular, the generator may provide the ultrasonic instrument with a current (e.g., a second current) less than the (first) current provided by the generator while the instrument is operating in a high power state, and as a result, this does not generate heat (or heat equivalent to that when the ultrasonic instrument is in a high power state) in the end effector. As a result, the ultrasonic instrument may begin to cool when it moves from a high power state to a low power state. Finally, if kept in a low power state, the temperature of the ultrasonic instrument may drop to (at least below) a threshold temperature (e.g., room temperature). In one embodiment, the second current may be less than a predetermined threshold current. In one embodiment, the blade may vibrate at the same frequency in the low-power state as in the high-power state. In another embodiment, the blade may vibrate within an allowable frequency range.

[0040] As a result, since the current supplied to the instrument is smaller when the instrument is in a low-power state, the blade of the end effector may be driven by the tool drive unit 21 of the handle in a different manner than when the instrument is in a high-power state. In particular, the blade may vibrate over a range of motion different from the range of motion over which the blade vibrates when the instrument is in a high-power state. For example, when the instrument is in a high-power state, the blade may vibrate over a first (e.g., high) range of motion, which may generate heat in the blade when pressed against an object, whereas when the instrument is in a low-power state, the blade may vibrate over a second (e.g., lower) range of motion, which may be less than the first range of motion (e.g., the blade is displaced less along the longitudinal Y-axis than in the first range of motion). In some embodiments, the second range of motion may be less than a minimum threshold (e.g., a threshold over which the blade generates heat if it vibrates beyond a minimum threshold). In one embodiment, the end effector may not generate frictional heat while vibrating over this downward range of motion, even when pressed against (in contact with) an object such as a blood vessel (for example, while the gripper is compressing the object). In one embodiment, the resonant frequency is maintained within an acceptable range regardless of the power state in which the instrument is operating.

[0041] In one embodiment, the difference in end effector vibration may be based on the amount of power drawn by the ultrasonic instrument while in different states. For example, the range of motion displaced while the blade is oscillating may be based on (e.g., proportionally) the power drawn by the instrument, so that more power drawn by the instrument may cause the blade to vibrate over a higher range of motion. Conversely, while the ultrasonic instrument is in a low-power state, the instrument may draw less power, causing the blade to vibrate less (than when the instrument is in a low-power state). As a result of oscillating over smaller displacements, the blade may not generate frictional heat (e.g., while in contact with tissue). In another embodiment, the blade may generate some frictional heat while in a low-power state and in contact with the object, but this may be less than the heat generated when the instrument is in a high-power state. In this case, this generated frictional heat may not be sufficient to cut and / or seal the tissue. In some embodiments, as a result of operating at a low power level, the end effector of the ultrasonic instrument may enter a cooling cycle, thereby dissipating the heat generated by the end effector while the instrument was at a high power level (for example, over a period of time). In another embodiment, the blade may not vibrate during this low power level (for example, the tool drive unit may not drive the blade).

[0042] In one embodiment, the system may enter (or operate in) at least one of the power states based on a user input (e.g., received by the generator 25). In particular, the generator may provide power to the ultrasonic instrument based on receiving a user input to one or more input devices (e.g., an input to a foot pedal, a UID controlled by an operator and coupled communicably to the system 1, and / or an input at the handle 21 of the ultrasonic instrument). Power provided based on the user input may put the ultrasonic instrument into a high-power state in which the ultrasonic instrument draws power from the generator to heat the end effector 23 (e.g., the blade 30 of the end effector 23). For example, when the generator receives a (first) user input (e.g., by an operator pulling or pressing a trigger on the handle 21), the generator may provide current to the ultrasonic instrument (e.g., the tool drive unit of the ultrasonic instrument), which uses the current to drive the end effector as described herein. Therefore, when the trigger controls the hinged arm of the end effector, the generator is configured to provide current when the hinged arm is moved (for example, by at least a threshold distance toward the blade 30). In another embodiment, the system may enter a low-output state based on another (for example, a second) user input (for example, receiving input from a different input device coupled to the generator, such as a foot pedal).

[0043] In some embodiments, the ultrasonic instrument may be configured to switch between a high-power state and a low-power state. As described herein, the instrument may operate in a high-power state while the generator is receiving user input (e.g., the user pulls or presses a trigger on the handle). The instrument may operate in a low-power state in response to the generator no longer receiving user input. For example, the ultrasonic instrument may switch from a high-power state to a low-power state in response to the user releasing the trigger on the handle, and the generator may transition between the two states. In one embodiment, as described herein, the instrument may operate in a low-power state while the operator is not actively using the instrument to perform ultrasonic instrument operation. Specifically, the system may enter a low-power state, but no user input is received to one or more input devices used by the operator to enter a high-power state. However, if the operator wishes to actively use the ultrasonic instrument, the ultrasonic instrument may switch back to a high-power state (e.g., in response to user input). In another embodiment, the instrument may operate in a low-power state in response to receiving user input (e.g., the user pressing a button on the UID). In another embodiment, the instrument may operate in this state for a period of time. As described herein, the surgical system is configured to determine the temperature of the end effector while in a low-power state (e.g., after switching from a high-power state) in order to inform the operator of the temperature that may become high due to the instrument operating in a high-power state. When the end effector has cooled to a certain temperature (e.g., below a predetermined temperature), at which temperature the end effector may not cause thermal damage even if it comes into contact with tissue, the generator may stop the instrument by ceasing to supply a lower current.

[0044] In one embodiment, the generator may provide different levels of current to heat the blade, which may be based on user input. For example, the generator may receive a first user input (e.g., from one petal coupled to the generator) and accordingly provide the ultrasonic instrument with a maximum (allowable) amount of current. The ultrasonic instrument may then drive the end effector over its maximum (e.g., predefined) range of motion, which may result in the end effector generating heat at a (first) high temperature. However, if the generator receives a second user input (e.g., from another petal coupled to the generator), the generator may provide a smaller amount of current to the ultrasonic instrument. As a result, the ultrasonic instrument may draw less power to vibrate the end effector over a (second) lower range of motion, which may be lower than the first range of motion over which the blade vibrates in response to the first user input. However, this lower range of motion may cause the end effector to heat to a temperature lower than the first temperature of the end effector when the ultrasonic instrument draws more current (in response to the generator receiving a first user input). Different types of tissue may be cut and / or cauterized by heating the end effector to different temperatures. For example, to cut and / or cauterize fattier tissue, the end effector may need to be hotter (having a first temperature), while thinner (and less fattier) tissue may need less heat (having a second temperature). In another embodiment, the generator may be configured to provide one type of current while in a high-power state (e.g., to drive the end effector over a first high range of motion).

[0045] As described herein, an ultrasonic instrument may be activated based on whether the end effector is in a closed position to grasp an object (e.g., a piece of tissue) (e.g., it may operate at high power). For example, an ultrasonic instrument may be activated (e.g., by the user) so that it can operate at high power to draw a current sufficient to generate heat in the end effector. In particular, the generator may be activated when it receives a user input to close the end effector (e.g., to move the hinged arm 31 within the distance of the blade 30). When a user input to move the hinged arm is received, the generator may be configured to provide (e.g., sufficient) power to activate the instrument, as described herein. In some embodiments, the generator may be activated based on the determination that the hinged arm and / or blade are in contact with an object. For example, the ultrasonic instrument may include one or more sensors (e.g., force sensors / pressure sensors) that detect the presence of an object and / or that the object is in contact with both arms. In particular, the generator may enter a high-power state if it is determined that the gripping device is compressing the object (based on the pressure detected by the sensor exceeding a threshold). Upon making this determination, the generator may provide a first current to oscillate the blades in order to generate heat. When the pressure reading drops below the threshold (meaning the object has been released by the gripping device), the generator may switch to a low-power state.

[0046] In one embodiment, the surgical system (e.g., its generator) may be configured to determine one or more characteristics of the ultrasonic instrument (or its end effector) while the instrument is in one or more power states. For example, the generator may be configured to track (or monitor) characteristics such as input voltage, input current, resonant state, resonant frequency, and / or (e.g.) the (e.g., mechanical) impedance of the ultrasonic instrument (or its end effector). In one embodiment, the “resonant frequency” may be the frequency at which an object, such as the ultrasonic instrument (e.g., a portion of its end effector), vibrates (e.g., spontaneously). In this case, the resonant frequency may be the frequency at which the end effector vibrates while it is in a heated and / or cooled state. In some embodiments, the resonant frequency of the end effector may vary based on the temperature of the end effector (e.g., the blade 30 of the end effector). Resonant frequencies will be further described herein. In one embodiment, the generator may be configured to monitor at least some of these characteristics of the instrument while the instrument is operating in a high-power state. The system may be configured to determine at least some of these characteristics while the appliance is in a low-power state (cooling cycle or cooling period) due to the appliance drawing at least some power. For example, the generator may determine the resonant frequency and impedance of the end effector (e.g., the blade 30 of the end effector) while in a low-power state. Further determination of these characteristics is described herein.

[0047] In one embodiment, the surgical system may include additional components. For example, the system may include a cable connecting the generator to an ultrasonic instrument (e.g., an ultrasonic transducer configured to convert a current-driven signal into mechanical vibrations). In one embodiment, the ultrasonic transducer may be connected to a waveguide connected to the blade 30 of the end effector 23.

[0048] As shown in the figure, the generator 25 also includes a display 24 arranged to display information regarding the operation of the ultrasonic instrument. For example, the display may show temperature information, the current state of the ultrasonic instrument, and one or more of the characteristics described herein.

[0049] Figure 4 is a block diagram of a surgical system 1 according to one embodiment. The system includes an ultrasound instrument 20, a generator 25, a controller 40, storage (memory) 44, a display 15, and a speaker 43 (which may be a separate speaker or part of an electronic device of the system such as a user console 2). In one embodiment, the system may include more or fewer elements, such as having two or more displays and / or not having a speaker. Although the elements are shown as separate, at least some may be parts of each other (or integrated). For example, the storage 44 may be part of the controller 40 (e.g., its internal memory). In another example, the controller 40 may be part of the generator 25 or part of a separate electronic device that can be communicatively coupled with the generator 25.

[0050] Examples of storage 44 (e.g., non-temporary machine-readable storage media) may include read-only memory, random-access memory, CD-ROM, DVD, magnetic tape, optical data storage device, flash memory device, and phase-change memory. Storage 44 includes one or more temperature models 45 which may be used by a surgical system 1 (e.g., its controller 40) to determine (estimate) one or more temperatures of (at least a portion of) an ultrasonic instrument 20. In particular, the temperature models may be configured to output temperature values ​​(e.g., in Celsius) in response to input of one or more parameters by the controller. In one embodiment, at least some of the models 45 may represent temperature estimates with respect to resonant frequencies. In some embodiments, one or more of the models 45 may output temperatures in response to one or more characteristics of the ultrasonic instrument, such as resonant frequencies, as input. The use of temperature models is further described herein.

[0051] In one embodiment, one or more temperature models 45 may be predefined models, such as those determined (or created) in a controlled setting (e.g., a laboratory), or they may be provided to a surgical system, such as those downloaded from a remote server over a network (e.g., the Internet). In one embodiment, the temperature model may be a machine learning (ML) model that can be trained (e.g., sequentially) to estimate temperature based on one or more sets of training data. In one embodiment, the ML model may be any type of ML model, such as a deep neural network (DNN) or a convolutional neural network (CNN). As described herein, at least some of the temperature models may be used by the controller 40 to estimate the temperature of the end effector of the ultrasonic instrument 20.

[0052] In another embodiment, the model may include different types of models based on the (current) state of the ultrasonic instrument, which may be used by the surgical system to estimate the temperature of the end effector 23. For example, model 45 may include one or more cooling temperature models that can be used by the system to estimate the temperature of the end effector while the instrument is in a cooling state, and / or one or more heating temperature models that can be used by the system to estimate the temperature of the end effector while the instrument is in a heating state. In another embodiment, model 45 may include a model based on the state of the end effector of the ultrasonic instrument. For example, model 45 may include one or more models that can be used by the system to estimate the temperature of the end effector while the end effector is in "air" (e.g., not in contact with an object). In particular, the end effector may be in air while the operator is holding the ultrasonic instrument 20 (e.g., its handle 21) such that an open space completely surrounds the end effector (e.g., its blade 30). In one embodiment, the end effector may be in contact with one or more objects while in air. For example, an object may be (inadvertently) attached to a portion of the blade, which may be based on the blade's temperature. In another embodiment, Model 45 may include one or more models that can be used by the system to estimate the temperature while the end effector is in contact with the object. In this case, the end effector may be considered to be in contact with the object when the operator operates the handle such that at least a portion of the end effector is pressed against the object by the operator. Different models are described further herein.

[0053] The storage 44 also includes one or more model coefficients 46, which may be terms, values, and / or functions that can be used by one or more of the temperature models 45 to calculate the estimated temperature. In one embodiment, the model coefficients may be based on the characteristics of the ultrasonic instrument. For example, the coefficients may include functions on characteristics (e.g., resonant frequencies) such that one or more coefficients may be estimated as the output of a function that responds to one or more characteristics as inputs. In some embodiments, the model coefficients may be numerical. In another embodiment, the model coefficients 46 may be stored in a lookup table that associates the model coefficients with one or more characteristics. In that case, the controller may be configured to estimate the model coefficients by performing a table lookup to a data structure using one or more determined characteristics of the ultrasonic instrument. Determining the coefficients is further described herein.

[0054] In one embodiment, the storage may include one or more models and / or model coefficients associated with a particular device (e.g., device-specific). For example, different ultrasonic instruments may have different physical properties, which may affect the rate at which the temperature rises or falls. As a result, the storage may include one or more models and / or model coefficients for different ultrasonic instruments. For example, the storage may include a first heating model for a first instrument and a second heating model for a second instrument.

[0055] In some embodiments, the controller 40 may be a dedicated processor such as an application-specific integrated circuit (ASIC), a general-purpose microprocessor, a field-programmable gate array (FPGA), a digital signal controller, or a set of hardware logic structures (e.g., filters, arithmetic logic units, and dedicated state machines). In one embodiment, the controller may be part of an electronic device such as a console computer system 16, a control tower 3, and / or a user console 2. Although shown as a single component, in another embodiment, the controller may comprise one or more electronic components (e.g., a processor, memory, etc.) that are communicably coupled on a single electronic device (e.g., a console computer system 16) or across multiple devices (e.g., communicating over a wireless computer network). In some embodiments, the controller may be part of a separate device, such as part of a remote server communicating with one or more electronic devices. In another embodiment, the controller may be part of a generator 25 as described herein (e.g., at least partially integrated within the generator 25). In that case, at least some of the other elements (e.g., speakers and displays) may also be part of the generator (e.g., integrated within the generator). As a result, at least some of the operations performed by the controller described herein may be performed by the generator 25.

[0056] In one embodiment, the controller may be configured to perform a temperature estimation operation of the surgical system 1 to determine the (e.g., real-time) temperature (or temperature change) of the ultrasonic instrument (e.g., its end effector) while the instrument is in one or more power states, such as a cooled state (e.g., a low-power state where the blade of the end effector is not actively heated to cut and / or seal tissue). Specifically, the controller may determine the temperature based on one or more characteristics of the ultrasonic instrument that are determined while the instrument is in a cooled state, such as the resonant frequency of the end effector (e.g., its blade). The controller may determine the temperature using one or more temperature models 45, thereby outputting an estimated temperature of the blade as input (in response) based on the resonant frequency. For example, the controller may determine whether the end effector of the ultrasonic instrument is in a heated state or a cooled state, which may be based on an estimated characteristic of the instrument (e.g., voltage, current, etc.). In response to determining that the system is in a heated state, the controller may estimate the end effector temperature based on the output of a first temperature model (e.g., a heating model) based on one or more characteristics, such as the resonant frequency of the appliance. In response to determining that the system is in a cooled state, the controller may estimate the end effector temperature based on the output of a second temperature model (e.g., a cooling model) based on one or more characteristics. The controller may be configured to provide a notification (e.g., display) based on the estimated temperature. As a result, the system can estimate the end effector temperature regardless of the operating state of the appliance, and the estimated temperature can be displayed to the operator (e.g., in real time). The operations performed by the controller are further described herein.

[0057] In one embodiment, (at least some) temperature estimation operations may be performed by the controller while the end effector is in a heated and / or cooled state. As described herein, the temperature estimation operations may be performed while the end effector is in a cooled state and “in air,” meaning that the blade is not in contact with any object such as tissue (and / or at least partially immersed in a liquid) (e.g., based on operator manipulation). In particular, as described herein, during laparoscopic surgery, one or more gases may be used to create a cavity in the patient’s abdomen. In this case, the temperature estimation operations may be performed while the end effector (or its blade) is inside the cavity, but while the end effector is floating in one or more gases inside the cavity (e.g., with the operator holding an ultrasonic instrument), or outside the cavity.

[0058] In another embodiment, the temperature estimation operation may be performed while the end effector of the ultrasonic instrument is in contact with the object. In one embodiment, one or more properties of the ultrasonic instrument may change based on whether the end effector (e.g., the blade of the end effector) is in the air or in contact with the object. For example, when the blade is in contact with the object, as in contrast to when the blade is in the air, its resonant frequency (or attenuated natural frequency, ω) may change due to an increase in the stiffness k of the blade. d ) may increase. In particular, the attenuated natural frequencies can be seen as follows:

[0059]

number

[0060]

number

[0061]

number

[0062] In one embodiment, at least some of the operations performed by the controller may be stored in the memory of the surgical system (e.g., storage and / or the controller's (internal) memory) and implemented by software (e.g., as instructions) and / or by hardware logic structures executed by the controller. In one embodiment, at least some of the operations performed by the controller may be performed each time the instrument enters a state (or switches between states, such as switching from a cooled state to a heated state). In another embodiment, the controller may periodically (e.g., every second) perform one or more of the operations described herein while the surgical system is in a particular state, so that the estimated temperature may be presented to the operator during a surgical procedure in which the ultrasonic instrument is being used.

[0063] As shown in the figure, the generator may receive user inputs (e.g., via one or more electronic devices coupled to the generator) to cause the generator to perform one or more operations. For example, user inputs may be received via the ultrasonic device (e.g., when the user pulls the trigger on the handle) to cause the generator to provide a current that switches the ultrasonic device from a low-power state to a high-power state, as described herein.

[0064] Figures 5-8 and 10 are flowcharts of processes 50-80 and 100, respectively, each including one or more operations that can be performed by the surgical system 1 (e.g., its controller 40 and / or generator 25) to perform temperature estimation operations as described herein. Specifically, the operations described herein may be performed while the ultrasonic instrument is being used by the operator during a surgical procedure. For example, at least some operations may be performed while the instrument is being used to perform a surgical task, and / or before (and / or after) the task is performed. In another embodiment, at least some of the operations may be performed by the generator 25 (e.g., its one or more processors). These figures will now be described with reference to Figures 1-4. In one embodiment, at least some of these operations may be performed while the ultrasonic instrument is in one of the one or more states described herein. For example, the operation described in process 60 of Figure 6 may be performed while the ultrasonic instrument is in a heated state. As another example, at least some of the operations in processes 70 and 80 in Figures 7 and 8 may be performed while the ultrasonic instrument is in a cooled state.

[0065] Referring to Figure 5, this shows a flowchart of one embodiment of a process 50 for estimating the temperature of the end effector of an ultrasonic instrument. Specifically, this process may be performed (at least partially) by the controller 40 to determine in what configuration (or state) the end effector of the ultrasonic instrument is operating in order to estimate the temperature of the end effector, and to estimate the temperature based on the determined configuration.

[0066] Process 50 begins with the controller 40 determining the input current to the ultrasonic instrument 20 (block 51). For example, the controller 40 may receive the input current from one or more sensors (e.g., current sensors) of the surgical system 1 (e.g., its instrument 20) that can monitor the current drawn out by the ultrasonic instrument. In another embodiment, the controller 40 may receive sensor data (e.g., characteristics) which may include the input current from a generator 25 that can be configured to monitor the data.

[0067] The controller 40 determines whether the ultrasonic instrument is in a heated state based on the input current (determination block 52). In particular, the controller determines whether the end effector of the ultrasonic instrument is in a heated state (e.g., being used to cut tissue) or in a cooled state (e.g., being held in the air by the operator so that the instrument can cool after being used to perform a surgical task). The controller 40 may determine what state the instrument is in based on the current being drawn by the instrument. For example, when an ultrasonic instrument is in a heated cycle, the instrument may draw a considerable amount of current. In particular, the instrument may draw a lot more current than the amount drawn by the instrument during a cooled cycle when heat is generated by the end effector, as described herein. In that case, the controller may be configured to determine whether the instrument is in a heated state based on whether the input current exceeds a current threshold. In one embodiment, the current threshold may be 0.1 mA to 4 mA. If the device is determined to be in a heated state (for example, based on the input current exceeding a current threshold), the controller 40 estimates the temperature of the end effector of the ultrasonic device based on a heating model (block 53). For example, the controller may predict the end effector temperature using a heating model from model 45 stored in storage 44. The estimation of temperature while the device is in a heated state is further described herein.

[0068] However, if the ultrasonic instrument is not in a heated state (for example, based on the input current being below a current threshold), the controller may determine that the instrument is in a cooled state. The controller 40 may be configured to determine the impedance of the end effector of the ultrasonic instrument (block 54). In particular, the impedance may be determined while the instrument is in a cooled state. As described herein, the impedance may be a mechanical impedance, which may be determined by the controller 40 using one or more of the (monitored) characteristics of the ultrasonic instrument, such as the input current and / or input voltage of the end effector. For example, the controller may use the input current and input voltage of the ultrasonic instrument (for example, used to drive the blades of the end effector) and determine the mechanical impedance based on these characteristics (for example, based on Ohm's law). In one embodiment, the input voltage may be varied to maintain a current which may be set to compensate for changes in impedance. In another embodiment, the controller may determine the impedance by applying one or more of the characteristics to an (e.g., predefined) impedance model (e.g., an electromechanical model of the impedance of at least a portion of the end effector) that outputs the mechanical impedance. In another embodiment, the controller may use any well-known method to determine the impedance of the blade. In one embodiment, the controller may receive the impedance from the generator 25.

[0069] The controller 40 determines, based on impedance, whether the end effector is in contact with an object (determination block 55). Specifically, the controller 40 determines whether the end effector is air-cooled or contact-cooled. In particular, the controller determines whether the end effector is in contact with an object such as tissue (for example, by the operator operating the ultrasonic instrument so that the end effector is in contact with the object) or in the air (for example, the ultrasonic instrument is operated by the operator so that it is floating in the air and not in contact with an object). In one embodiment, in order to determine whether the end effector is in contact with an object, the controller may determine whether the impedance is above an impedance threshold. In response to the determination that the impedance is above a threshold, the controller may determine that the end effector is in a cooling state while in contact with the object. The controller may be configured to estimate the temperature of the end effector of the ultrasonic instrument based on a contact cooling model (block 56). For example, if the controller determines that the end effector is in contact with an object, it may be configured to determine a cooling model (e.g., from Model 45) that takes into account the end effector's contact with the object, and to use the model to determine the temperature of the end effector. The estimation of the end effector temperature while the ultrasonic instrument is in a cooled state and in contact with an object is further described herein.

[0070] However, if the impedance is below the impedance threshold, the controller determines that the end effector is in a cooled state while it is in the air. The controller estimates the temperature of the end effector of the ultrasonic instrument based on an air-cooling model (block 57). In one embodiment, the air-cooling model used by the controller (which may be taken from model 45 in storage 44) may differ from the contact cooling model described herein. For example, the air-cooling model may be a polynomial model, while the contact cooling model may be an exponential model. The estimation of the end effector temperature while the ultrasonic instrument is in a cooled state and in the air is further described herein.

[0071] As a result, the controller 40 may be configured to determine what state the ultrasonic instrument is in, such as whether the instrument is in a heated state, in a cooled state while the end effector is in contact with an object, or in a cooled state while the end effector is in the air, and may be configured to estimate the temperature based on the state of the instrument. In one embodiment, the controller may perform at least some of these operations periodically and / or continuously while the instrument is in use, so that the controller can estimate the temperature of the end effector while the instrument is switching between states in order to provide the operator with a real-time temperature estimate. Thus, the surgical system can effectively, efficiently, and seamlessly provide the operator with a temperature estimate when the instrument is switching between states.

[0072] Figure 6 is a flowchart of one embodiment of a process for estimating the temperature of the end effector of an ultrasonic instrument while the end effector is in a heated state. In particular, at least some of the operations described in process 60 may be executed when the controller 40 determines that the ultrasonic instrument 20 is in a heated state (for example, in blocks 52 and 53 of process 50 in Figure 5).

[0073] Process 60 involves the controller 40 setting the start temperature T of the end effector of the ultrasonic instrument. Startbeginning by determining (block 61). In particular, the controller may be the time when the end effector entered the heated state (or was determined by the controller to have entered), the start time T Start may be determined. For example, the controller may determine T Start when the controller determines that the ultrasonic instrument is in a heated state (e.g., when the input current of the ultrasonic instrument exceeds a current threshold) in the determination block 52 of process 50 in FIG. 5 (or when the controller determines). In one embodiment, the controller may determine T Start at the time when the input current of the ultrasonic instrument is monitored to determine that the instrument is in a heated state, as described in process 50 of FIG. 5.

[0074] In one embodiment, T Start may be determined by the controller 40 based on the environment in which the instrument is located. In particular, T Start may be determined to be (substantially or equal to) the ambient temperature of the environment. For example, T Start may be determined based on temperature data received from a temperature sensor of the surgical system (e.g., ambient). In another embodiment, T Start may be based on the surgical site where the end effector is located. For example, as described herein, these operations may be performed while the ultrasonic instrument is being used to perform surgical tasks at the surgical site (e.g., inside the patient's abdomen) during a surgical procedure. In that case, the surgical system may determine T StartThis can be determined as the patient's (e.g., measured or estimated) body temperature. In one embodiment, the controller may determine the environment in which the end effector is located based on sensor data captured by one or more sensors of the surgical system. For example, the controller may be configured to run an object recognition algorithm on video data captured by one or more cameras of the system, and if the environment of the end effector is identified (based on the object recognition algorithm), the controller may determine the temperature of the environment. As an example, the controller may use the identified environment to perform a table lookup to a data structure that associates (e.g., ambient) temperature with the environment.

[0075] In another embodiment, T Start This may be based on the end effector temperature previously estimated by the controller 40. As described herein, the surgical system may perform the operations described herein to estimate the end effector temperature when switching between states, such as when the system switches between an air-cooled state and a heated state. In this case, the controller, T Start This can be estimated as the temperature (e.g., the last temperature) estimated by the controller while the system was in a previous (e.g., air-cooled) state before entering the current heated state. Further explanation of temperature estimation during the cooling state is provided herein.

[0076] Returning to Figure 6, the controller 40 initiates heating of the end effector of the ultrasonic instrument at the (first) resonant frequency RF HS Determine (block 62). In one embodiment, RF HS is, T Start This is the resonant frequency determined by the start time associated with it. For example, RF HS This could be the resonant frequency at the start time when the end effector enters (or transitions to) another state (such as the time it takes for the end effector to enter a heated state). In one embodiment, RF HS is, T StartThis can be determined (at least partially) at the same time as (or simultaneously with) the determination of the clock for surgical systems (for example, with respect to the clock for surgical systems).

[0077] In some embodiments, the controller (and / or generator) may electronically determine the resonant frequency. For example, the generator may sense the voltage and current waveforms (and the difference in phase angle between the two waveforms) used to drive the end effector (e.g., its blade). Specifically, the ultrasonic instrument 20 (e.g., tool drive unit) may include an ultrasonic transducer configured to vibrate the blade according to the input voltage and current waveforms. The frequency that generates the phase angle difference of a threshold (e.g., zero) is the resonant frequency. In that case, the surgical system is T Start At the time when it is decided (or T Start The RF uses one or more characteristics, such as voltage and current, which are detected (or measured) at the time the characteristics used to determine the characteristics are detected. HS It may be configured to determine the resonant frequency. In another embodiment, other well-known methods may be used to determine the resonant frequency.

[0078] The controller 40 determines the (second) resonant frequency RF of the end effector (block 63). In one embodiment, RF is RF HS The subsequent resonant frequency may be determined by the controller after the initial resonant frequency has been determined (for example, with respect to the clock in a surgical system). For example, the controller is RF HS RF can be determined at a time following the start time when the start time is determined. For example, RF HS The RF may be determined at a start time (e.g., T=0s), which may be the time when the system enters a heated state, or at a later time (e.g., T=1s). The controller 40 controls the change in the heating start resonant frequency ΔRF. HS Determine (block 64). In particular, the controller determines ΔRF HS =RF HS -RF, etc. HS ΔRF is calculated based on the difference between (first resonant frequency) and RF (second resonant frequency).HS It is possible to determine this.

[0079] Controller 40 is ΔRF HS The temperature change ΔT is determined (estimated) based on this (block 65). Specifically, the controller can determine ΔT using a heating model. For example, the temperature change is ΔRF as input to the model. HS The output of the heating model may be based on the following. In one embodiment, the controller can retrieve the heating model from the temperature models 45 stored in the storage 44. For example, the controller may perform a table lookup to a data structure containing the temperature models 45 based on one or more parameters. In particular, the controller may select a heating model from the temperature models 45 associated with the ultrasonic instrument 20. As described herein, the storage may include device-specific models. In this case, the controller may determine an identifier associated with the ultrasonic instrument and select a temperature model associated with the identifier. In one embodiment, the selected model may be a polynomial model, such as a cubic polynomial. In another embodiment, the heating model may be a quadratic polynomial. In some embodiments, the heating model may be any type of model, such as an exponential model.

[0080] The controller is T Start And the temperature of the end effector T based on ΔT H Determine (block 66). In particular, controller 40 determines T H =T StartThe end effector temperature can be determined by adding (combining) temperatures such that +ΔT. Thus, the controller estimates the end effector temperature based on the end effector's starting temperature, starting resonant frequency, and subsequent resonant frequencies. The controller 40 presents a notification based on the end effector temperature (block 67). For example, system 1 may display a pop-up notification on display 15 indicating the estimated temperature. In another embodiment, the controller 40 may output an audible notification through one or more speakers (e.g., speaker 43). For example, the audible notification may be one or more sounds indicating the end effector temperature (e.g., beeps), such as a series of sounds that may indicate that the temperature is above a temperature threshold. In another embodiment, the notification may be spoken language (e.g., "The instrument is 300°!"). In another embodiment, any type of notification may be presented.

[0081] As shown in the illustration, Figures 7 and 8 include several operational blocks that are included in (and described in relation to) Figure 6, such as blocks 61, 63, and 67. For brevity, at least some of these operational blocks described in relation to Figure 6 will not be described again in relation to Figures 7 and 8.

[0082] Referring to Figure 7, this figure shows a flowchart of one embodiment of process 70 for estimating the temperature of the end effector of an ultrasonic instrument while the end effector is in a cooling state. In one embodiment, the controller 40 may perform at least some of the actions of process 70 when it determines that the ultrasonic instrument is in a cooling state, as described in process 50 of Figure 5. In another embodiment, the actions may be performed when the controller 40 determines that the ultrasonic instrument is transitioning from a heating cycle to the (current) cooling cycle (for example, when user input for activating the end effector of the ultrasonic instrument to perform a surgical task such as cutting and cauterizing tissue is no longer received via the generator 25).

[0083] Process 70 involves the controller 40 setting the start temperature T of the end effector of the ultrasonic instrument. Start It begins by determining (block 61). For example, the controller is T Start This can be defined as the estimated temperature (for example, last) during the heating cycle before the ultrasonic instrument enters the current cooling cycle. The controller 40 sets the cooling start resonance frequency RF of the end effector of the ultrasonic instrument. CS Determine (block 71). For example, RF CS is, T Start It may be determined at the same start time as it is determined. In another embodiment, RF CS This can be determined when the controller 40 determines that the ultrasonic device is in a cooling cycle (for example, based on the input current of the ultrasonic device being below a current threshold).

[0084] The controller 40 determines the (e.g., subsequent) resonant frequency RF of the end effector (block 63). The controller determines the impedance I of the end effector (block 72). For example, the impedance may be a mechanical impedance, which can be determined by the controller 40 using one or more of the (monitored) characteristics of the ultrasonic instrument, such as input current, as described herein. Based on the impedance I and the resonant frequency RF, the controller 40 determines the corrected resonant frequency RF Corrected Determine (block 73). In particular, RF CorrectedThis can compensate for changes in one or more physical properties of the ultrasonic instrument that may have occurred while the ultrasonic instrument was in a previous heating cycle. For example, as described herein, the resonant frequency of an ultrasonic instrument may be proportional to the mass, m, of the instrument end effector (e.g., blade). During use of the end effector in a heating cycle, a portion of an object, such as tissue, may inadvertently adhere to a portion of the blade. As a result, m may increase due to the object attached to the blade. Thus, the mass of the blade may increase due to one or more portions of an object adhering to the blade while the end effector is in the air. As a result, the measured resonant frequency may become inaccurate. Therefore, to account for changes in the physical properties of the end effector, the controller compensates for the RF to compensate for the RF Corrected You may generate this.

[0085] In one embodiment, the controller uses an RF (Resonant Frequency) correction model (e.g., retrieved from storage 44) to perform RF Corrected The model may be determined. In some embodiments, the model may be device-specific so that the controller retrieves the model using characteristics such as one or more identifiers of the ultrasonic instrument for retrieving the model. In that case, the controller may use the identifiers to select the corresponding RF model and perform a table lookup to a data structure that associates the RF correction model with the characteristics. In some embodiments, the controller uses the model to adjust the resonant frequency RF as the output of the model in response to I as the input to the model. Adjusted , can be determined. In one embodiment, the model responds to I with RF Adjusted The output may be a (e.g., first-order) polynomial model. In another embodiment, the RF correction model may be any type of model. The controller is RF Corrected =RF+RF Adjusted To achieve this, RF to RF Adjusted By adding RF Corrected The controller determines the RF CorrectedBased on this, the change in the cooling start resonant frequency ΔRF CS Determine (block 74). In particular, the controller is ΔRF CS =RF Corrected -RF CS RF Corrected and RF CS Based on the difference between the two, ΔRF CS It is possible to determine this.

[0086] The controller 40 determines whether the end effector is in contact with the object (determination block 75). For example, the controller may determine whether the end effector is in contact with the object or in the air based on whether I is above an impedance threshold, as described herein. If so, the controller 40 determines one or more model coefficients of a contact cooling temperature model (block 76). In particular, the controller may determine model coefficients and / or a contact cooling temperature model that can be used by the controller to estimate the temperature of the end effector while the end effector is in contact with the object and in a cooling state. In one embodiment, the controller may determine the coefficients and model (for example, based on the characteristics of an ultrasonic instrument), as described herein, or it may retrieve the coefficients and model from storage 44.

[0087] In one embodiment, the controller is RF CS Model coefficients can be determined using RF. For example, the controller uses RF CS You may use this to perform a table lookup to model coefficients 46 and select one or more coefficients that can be associated with the cooling start resonance frequency.

[0088] In one embodiment, the temperature model used while the end effector is in contact with an object may differ from the temperature model used while the end effector is in air. For example, when a hot object is in contact with a cold object, heat is transferred from the hot object to the cold object (e.g., via conduction). In one embodiment, the rate at which conduction cools an object such as the end effector 23 may be faster than when the end effector is air-cooled. As a result, the contact cooling temperature model may be configured to account for a faster cooling rate than the air-cooling temperature model that may be used by the system 1 when the end effector is in air. In one embodiment, to account for the rate, the contact cooling temperature model may be an exponential model, while the air-cooling temperature model may be a (e.g., quadratic) polynomial model, and both models may have one or more model coefficients and / or RF as described herein. CS The system outputs a temperature change ΔT in response to an input that may include the following: In one embodiment, the exponential model can output a higher ΔT than the polynomial model for the same input. This may be because the end effector may cool more quickly when transferring heat by conduction while in contact with another object (e.g., it may drop to a threshold temperature in less than a certain period of time), while it may not cool as quickly when transferring heat into the air by convection (e.g., the time it takes to drop to a threshold temperature may exceed that period). In another embodiment, both models may be of the same type. Both models may be polynomial models but of different degrees; for example, the contact cooling model may be a cubic polynomial (e.g., cube) model, while the air cooling model may be a quadratic polynomial model.

[0089] Controller 40 has a cooling start resonant frequency ΔRF CS Based on the (changes) and model coefficients, the temperature change ΔT is determined using the contact cooling temperature model (block 77). For example, the controller is as follows: ΔRF CS And the model coefficients can be input into the exponential model:

[0090]

number

[0091] Returning to the determination block 75, if the end effector is not in contact with the object, the controller determines the model coefficients of the air-cooled temperature model (block 79). In one embodiment, the controller 40 can determine the model coefficients based on the air-cooled temperature model. As described herein, the air-cooled temperature model may be a quadratic polynomial model. In this case, the model may include three model coefficients a, b, and c. In one embodiment, the controller determines the RF CS The model coefficients can be determined based on the following. For example, each of the model coefficients can be based on a function of the resonant frequency f as follows: a=f a (RF CS ) b=f b (RF CS ) c=f c (RF CS ) Here, each of the coefficients is RF CS This can be determined by applying the corresponding resonant frequency function. In one embodiment, to determine the model coefficients, the controller uses their corresponding function f a ,f b and f cThe controller can determine at least some of the functions based on one or more characteristics, such as an ultrasonic instrument identifier. In particular, the functions may be device-specific, so that the functions may vary between different ultrasonic instruments. As a result, the controller can select functions using characteristics such as an ultrasonic instrument identifier (for example, by performing a table lookup to a data structure that stores the functions associated with the characteristics). In another embodiment, the model coefficients 46 stored in memory may include coefficients for different devices. As a result, the controller can determine RF CS The coefficients can be determined by using one or more characteristics of the device and performing a table lookup to a data structure that stores the model coefficients 46 in storage.

[0092] The controller 40 determines ΔT using an air-cooled temperature model based on the cooling start resonance frequency (change) and model coefficients (block 81). For example, the controller determines ΔRF as follows: CS Based on the input and the determined polynomial model coefficients, ΔT can be determined as the output of a (e.g., quadratic) polynomial (e.g., quadratic) model.

[0093]

number

[0094] The controller 40 determines the temperature T of the end effector based on the starting temperature and the temperature change (block 78). In particular, T is T = T Start T Start This can be a combination of and ΔT. The controller 40 presents a notification based on the determined temperature of the end effector (block 67).

[0095] In one embodiment, process 70 in Figure 7 includes an operation for estimating the temperature of the end effector of an ultrasonic instrument. This process may be performed using data that can be collected (e.g., dynamically) by the ultrasonic instrument, such as the resonant frequency. In another embodiment, system 1 may be configured to estimate the temperature using one or more start conditions and / or one or more end conditions of system 1. In this case, the system can estimate the temperature of any particular device without needing to collect data from the ultrasonic instrument. Figure 8 illustrates a process in which temperature can be estimated using such conditions.

[0096] Referring to Figure 8, this figure shows a flowchart of another embodiment of process 80 for estimating the temperature of the end effector 23 of an ultrasonic instrument 20 while the end effector is in a cooling state. In particular, process 80 includes the operation of estimating the temperature of the end effector based on the baseline characteristics (or start conditions) of the end effector. In one embodiment, the baseline characteristics may be characteristics specific to a particular type of ultrasonic instrument. In another embodiment, the baseline characteristics may be determined while the ultrasonic instrument is in an start state, such as after a period of time since it was started (or plugged into the power supply). Further determination of these characteristics will be described further herein.

[0097] Process 80 involves the controller detecting the baseline resonant frequency RF of the end effector (e.g., blade) of the ultrasonic instrument. Baseline The process begins by determining (block 81). In one embodiment, RF Baseline This may be determined at an initial time t0, such as when the ultrasonic instrument 20 is coupled to the generator 25 (e.g., inserted). For example, when the instrument is inserted into the generator, the controller uses RF to determine one or more properties (e.g., as described herein). Baseline To determine this, one or more diagnostic actions may be performed on the instrument. In another embodiment, the generator is RF BaselineIt may be configured to determine and provide a frequency to the controller 40. Thus, based on the operation, the generator may determine the baseline frequency of the blade of the end effector and provide that frequency to the controller.

[0098] In some embodiments, this baseline resonant frequency may be determined while the end effector is at room temperature (or near room temperature) (e.g., a temperature between 20-25° C.) and / or while the end effector is in air (e.g., while the blade of the end effector is not touching an object). In another embodiment, the baseline resonant frequency may be determined once and stored in the storage 44 of the surgical system 1 (or the memory of the controller 40). For example, the baseline frequency may be determined when the instrument is first coupled to the generator, stored in the storage 44, and retrieved by the controller when needed. In another embodiment, the baseline frequency may be determined each time the ultrasonic instrument is plugged into the generator. In another embodiment, the baseline frequency may be determined at startup of the surgical system (e.g., during initial power-on) (e.g., the ultrasonic instrument of the surgical system). In another embodiment, the baseline frequency may be a previously (e.g., during a previous implementation of process 80) determined resonant frequency.

[0099] In one embodiment, the RF Baseline may be determined while the ultrasonic instrument is in a low power state, the end effector is in an open position, and / or the ultrasonic instrument (e.g., its end effector and shaft) is not in contact with any object. In another embodiment, the RF Baseline may be determined (e.g., each time) when the ultrasonic instrument enters a cooling period.

[0100] The controller 40 determines the baseline temperature T Baseline of the end effector (block 82). In one embodiment, the baseline temperature may be room temperature (or near room temperature). In another embodiment, T Baselinemay be the temperature measured by a temperature sensor of a surgical system. For example, T Baseline may be the temperature of the end effector after a certain period in the environment. In another embodiment, T Baseline may be the temperature of the end effector measured after the end effector has been in a cooling state for a certain period. In some embodiments, T Baseline may be a predefined temperature.

[0101] In one embodiment, the operations described in blocks 81 and / or 82 may be executed at any time. In particular, the operations may be executed before the ultrasonic instrument enters the current cooling state.

[0102] The controller 40 determines the starting temperature T Start of the end effector of the ultrasonic instrument (block 61). The controller 40 determines the cooling start resonance frequency RF CS of the end effector (block 71). The controller 40 determines the resonance frequency RF of the end effector (block 63) and determines the impedance I of the end effector (block 72). The controller 40 determines the corrected resonance frequency RF Corrected based on I and RF as described herein (block 73). The controller determines whether the end effector is in contact with an object (decision block 75).

[0103] In response to determining that the end effector is not in contact with an object (e.g., in air), the controller 40 determines the model coefficients of the in-air cooling temperature model based on T Start , RF CS , RF Baseline , and / or T Baseline (block 85). As described herein, the temperature of the end effector can follow a polynomial curve such that the temperature can be defined as the following polynomial function.

[0104]

Equation

[0105] In that case, the model coefficients can be determined based on the initial and termination conditions of the end effector. In particular, the initial condition may be the starting temperature relative to the cooling start resonance frequency, which can be defined as follows:

[0106]

number

[0107] The termination condition may include the baseline condition of the end effector (for example, when the end effector has cooled to a threshold temperature such as room temperature), which may be the baseline temperature relative to the baseline resonant frequency, and this may be defined as follows:

[0108]

number

[0109] In addition, the model is a quadratic polynomial, and the slope at the end of cooling can be equal to zero, so as a termination condition, T Baseline We can take the derivative of the function, and as a result, we obtain the following linear polynomial.

[0110]

number

[0111] In particular, the derivative of the model can be zero because it converges to the baseline temperature (for example, it may converge asymptotically). By knowing the initial and termination conditions, the polynomial can be added to a 3x3 polynomial matrix that, when multiplied by the model coefficient matrix (extracted from the polynomial), equals the temperature matrix, as follows:

[0112]

number

[0113] Since the start temperature and baseline temperature, as well as the start resonant frequency and baseline resonant frequency, are known, the controller 40 can solve for each of the model coefficients according to a matrix equation. In particular, the model coefficients of the coefficient matrix can be determined by multiplying each side by an inverse 3x3 polynomial matrix. In one embodiment, the controller can determine the model coefficients by performing a table lookup to a data structure of the model coefficients 46 using the known temperature and resonant frequency. In one embodiment, the model coefficients determined based on the initial and ending conditions may be device-specific. In another embodiment, the coefficients may not be device-specific.

[0114] The controller 40 determines the temperature using an air-cooled temperature model based on the (corrected) resonant frequency and the determined model coefficients (block 86). In particular, the (e.g., current) temperature T of the end effector can be defined as follows:

[0115]

number

[0116] Returning to the judgment block 75, if the end effector is in contact with the object, the controller 40 will T Start RF CS RF Baseline , and / or T BaselineBased on this, the model coefficients of the contact cooling temperature model are determined (block 83). As described herein, the temperature of the end effector can decrease more rapidly while in contact with the object, as opposed to while in air, so the contact cooling temperature model can take into account the rate at which the end effector cools. As a result, the temperature of the end effector can follow a cubic polynomial curve, such that the temperature of the end effector can be defined as the following function:

[0117]

number

[0118]

number

[0119] The termination condition can be a baseline condition that can be defined as follows:

[0120]

number

[0121] Furthermore, the slope at the end of cooling can be equal to zero, so as a termination condition, T Baseline The first and second derivatives of can be taken, and the following results are obtained.

[0122]

number

[0123] By knowing the initial and termination conditions, the polynomials can be added to a polynomial matrix that, when multiplied by the model coefficient matrix, equals the temperature matrix, as shown below.

[0124]

number

[0125] The controller 40 may be configured to solve for each of the four model coefficients by multiplying each side of the matrix equation by an inverse 4x4 polynomial matrix, as described herein. The controller 40 determines the temperature using a contact cooling temperature model based on the (corrected) resonant frequency and the four determined model coefficients (block 84). In particular, the end effector temperature T may be defined as follows:

[0126]

number

[0127] Figure 9 shows several stages of a surgical system display illustrating actions performed by the end effector of an ultrasonic instrument and indicating the temperature of the end effector. Specifically, each of the four stages 90-93 shows a display 15 displaying an endoscopic video 94 (captured by the endoscope during the surgical procedure) showing the end effector 23 and the shaft 22 of the ultrasonic instrument, as well as a portion of the object 95 (e.g., tissue such as blood vessels) at the surgical site (e.g., inside the patient's abdomen). Each stage also shows a notification 96 overlaid on the portion of the endoscopic video 94. The notification 96 includes information regarding the state and temperature of the end effector. In one embodiment, the state and / or temperature may be determined by the surgical system according to at least one of the temperature estimation operations described herein. In one embodiment, the display showing the endoscopic video may be a different display of the surgical system, such as the display 24 of the generator 25. In some embodiments, the display may show other content, such as a graphical user interface (GUI) of a surgical system showing other video content and / or one or more UI items (e.g., related to a surgical procedure being performed by the system operator).

[0128] The first stage 90 indicates that the end effector is gripping a portion of the tissue to cut it. At this stage, the hinged arm 31 is in the closed position, so that the ultrasonic instrument is in or can enter a heating cycle, thereby compressing the tissue between the arm 31 and the blade. Thus, as described herein, during the closed position and heating cycle, the blade can cut the tissue using the frictional heat generated by the oscillation of the blade.

[0129] In addition, the surgical system may be configured to perform a temperature estimation operation to determine whether the end effector is operating and to estimate the temperature of the end effector. In particular, the surgical system 1 (e.g., its controller 40) may perform at least some of the operations described herein to determine whether the ultrasonic instrument is in a heating cycle. For example, the system may determine whether the input current to the ultrasonic instrument is above (or equal to) an input current threshold, as described in process 50 of Figure 5. If it is determined that the input current is above the threshold, the system may estimate the temperature using a heating model, as described in process 60 of Figure 6. As shown in the figure, the system presents a notification 96 (e.g., a pop-up) indicating the result of the temperature estimation. Specifically, the notification 96 indicates that the system is in a heating cycle and the temperature is 300°C.

[0130] The second stage 91 shows the result of the end effector 23 cutting the tissue 95. In particular, this stage shows that the tissue has been cut into two small pieces. In addition, the ultrasonic instrument is in the air, in a cooling cycle with the hinged arm in the open position. Therefore, at this stage, the surgical system may be configured to determine that the ultrasonic instrument has transitioned from a heated state to a cooled state based on a change in one or more characteristics. For example, the system may determine that the input current is below an input current threshold, as shown in Figure 5. In response, the system may estimate the temperature of the end effector based on a cooling model. Specifically, the system may determine that the end effector 23 is in the air based on characteristics such as the impedance of the end effector, and may perform a temperature estimation operation using an air-cooled temperature model, as shown in Figures 7 and / or 8. This stage shows the result of the temperature estimation while the end effector is in the air by changing notification 96 to indicate that the state of the end effector is currently cooling and the temperature is 290°.

[0131] The third stage 92 indicates that the end effector 23 has been moved upward to allow the end effector to continue cooling in the air. In one embodiment, the surgical system may continue performing a temperature estimation operation to dynamically (in real time) update the temperature of the end effector. As a result, notification 96 indicates that the temperature has decreased from 290°C to 238°C.

[0132] The fourth stage 93 indicates that the blade 30 of the end effector 23 has moved and is now in contact with the tissue 95. This stage also indicates that a notification 97 indicating “End Effector Contact” is displayed on the display 15 to inform the operator that the end effector (its blade) is in contact with the object. As described herein, the surgical system 1 may be configured to determine whether the end effector is in contact with the object or in the air based on the impedance of the end effector. In particular, if it is determined that the impedance is above (or equal to) an impedance threshold, the surgical system may transition from temperature estimation using an air-cooled model (from the third stage 92) to temperature estimation using a contact-cooled model, as shown in either (or both) of Figures 7 and 8. As a result of the temperature estimation, the notification 96 is updated to indicate that the temperature is currently 108°.

[0133] Thus, this figure illustrates how the controller 40 can continuously monitor and update the operator with the status and temperature of the appliance by performing at least some of the operations of the processes described herein (for example, continuously).

[0134] Figure 10 is a flowchart of another embodiment of process 100 for estimating the temperature of the end effector of an ultrasonic instrument. Process 100 begins with the controller 40 receiving the resonant frequency of the end effector of the ultrasonic instrument (block 101). For example, the resonant frequency may be the starting resonant frequency. The controller determines whether the end effector of the ultrasonic instrument is in a heated state or a cooled state (block 102). As described herein, the controller may determine the state of the ultrasonic instrument based on one or more characteristics of the instrument, such as the input current and / or impedance. In response to determining that the end effector is in a heated state, the controller estimates the temperature of the end effector based on the output of a first temperature model (e.g., the heating model described herein) having an input based on the resonant frequency of the end effector (block 103). However, in response to determining that the end effector is in a cooled state, the controller estimates the temperature of the end effector based on the output of a second temperature model (e.g., an air-cooled model or a contact-cooled model) which has an input based on the resonant frequency (block 104). The controller then presents a notification based on the estimated temperature (block 105).

[0135] Some embodiments may perform variations of at least some of the processes described herein. For example, at least some specific actions of a process may not be performed in the exact order illustrated and described. Certain actions may not be performed in a single continuous series of actions, and different specific actions may be performed in different embodiments. For example, actions within dashed boxes may be optional actions that do not have to be performed while (or each time) each process is being performed. In another embodiment, one or more actions with solid bounding boxes may be optional. In one embodiment, at least some of the actions described herein (performed, for example, in one or more processes described herein) may be performed automatically (for example, without user interference). For example, at least some actions may be performed at any stage during a surgical procedure in which an ultrasonic instrument is being used by an operator. In some embodiments, at least some of the actions described herein may be performed in real time (for example, continuously) (for example, while ultrasound is being used during a surgical procedure), and / or at least some actions may be performed before use during a surgical procedure.

[0136] As described herein, the surgical system 1 may be configured to perform a temperature estimation operation based on one or more determined characteristics of an ultrasonic instrument, such as a resonant frequency. In one embodiment, the characteristics used by the surgical system may be an average over a period of time. For example, the second resonant frequency RF determined in block 63 of process 60 in Figure 6 may be the average resonant frequency over a period of time (e.g., 10 seconds).

[0137] As described herein, the controller may estimate and display the temperature of the end effector. In one embodiment, the temperature of the end effector (or an index of temperature) may be displayed as a separate notification (or within the same notification) from a notification indicating the state of the end effector. In another embodiment, the notification presented by the controller may include other information, such as whether the end effector is in contact with an object or in the air.

[0138] In some embodiments, the controller may update the baseline resonance frequency and / or baseline temperature when the ultrasonic instrument switches from a heating cycle to a cooling cycle and / or vice versa. In particular, the controller may determine that the ultrasonic instrument is in a heating cycle (e.g., the end effector is in the closed position) and, in response to determining that the ultrasonic instrument has returned to a cooling cycle (e.g., the end effector is now in the open position and / or in air), the controller may monitor the resonance frequency of the end effector over a period of time (e.g., start) to determine a new baseline resonance frequency.

[0139] As described above, one embodiment of the present disclosure may be a non-temporary machine-readable medium (such as a microelectronic memory) storing instructions thereon for programming one or more data processing components (collectively referred to here as “processors”) to perform ultrasonic instrument operation and / or temperature estimation operation as described herein (automatically). In other embodiments, some of these operations may be performed by specific hardware components, including hardwired logic. Alternatively, these operations may be performed by any combination of programmed data processing components and fixed hardwired circuit components.

[0140] In interpreting the claims attached herein, the applicant wishes to note, for the assistance of the Patent Office and any reader of any patent issued in this application, that no claim or element of a claim is intended to exercise Section 112(f) of the United States Patent Act unless the words “means for” or “steps for” are expressly used in a particular claim.

[0141] While several embodiments have been described and illustrated in the accompanying drawings, these embodiments are merely illustrative of the broader disclosure and not limiting it. Since various other modifications may be conceivable to those skilled in the art, it should be understood that this disclosure is not limited to the specific configurations and arrangements illustrated and described. Therefore, this description should be considered illustrative rather than restrictive.

[0142] In some embodiments, the disclosure may include language, for example, "[Element A] and [Element B] at least one of them." This phrase may refer to one or more of the elements. For example, "[A and B at least one of them]" may refer to "[A]", "[B]", or "[A and B]". Specifically, "[A and B at least one of them]" may refer to "[A and B at least one of them]" or "[A or B at least one of them]". In some embodiments, the disclosure may include language, for example, "[Element A], [Element B], and / or [Element C]". This phrase may refer to any of the elements or any combination thereof. For example, "[A, B, and / or C]" may refer to "[A]", "[B]", "[C]", "[A and B]", "[A and C]", "[B and C]", or "[A, B, and C]".

[0143] [Implementation Method] (1) A method, Determining the resonant frequency of the end effector of an ultrasonic instrument, To determine whether the end effector of the ultrasonic device is in a heated state or a cooled state, In response to determining that the end effector is in the heated state, the temperature of the end effector is estimated based on the output of a first temperature model having an input based on the resonant frequency. In response to determining that the end effector is in the cooling state, the temperature of the end effector is estimated based on the output of a second temperature model having an input based on the resonant frequency. To provide a notification based on the estimated temperature, Methods that include... (2) The resonant frequency is a first resonant frequency at the start time when the end effector enters the heated state or the cooled state, and the method is Determining the start temperature of the end effector at the aforementioned start time, Determining the second resonant frequency of the end effector of the ultrasonic device at a time following the aforementioned start time, It further includes, The temperature is estimated based on the starting temperature, the first resonant frequency, and the second frequency. The method according to Embodiment 1. (3) In response to determining that the end effector is in the heated state, the temperature is estimated as follows: The temperature change of the end effector is determined based on the difference between the first resonant frequency and the second resonant frequency, Combining the aforementioned temperature change with the aforementioned starting temperature, The method according to Embodiment 2, including the method described above. (4) In response to determining that the end effector is in the cooling state, the temperature is estimated as follows: To determine whether the end effector is air-cooled or contact-cooled, In response to determining that the end effector is air-cooled, the temperature of the end effector is estimated based on the output of the first cooling temperature model, In response to determining that the end effector is being contact-cooled, the temperature of the end effector is estimated based on the output of a second cooling temperature model, The method according to Embodiment 1, including the method described above. (5) The method according to Embodiment 4, wherein the first cooling temperature model is a polynomial model and the second cooling temperature model is an exponential model.

[0144] (6) The resonant frequency is the first resonant frequency, and the temperature of the end effector is estimated based on the output of the second temperature model, Determining the model coefficients of the second temperature model based on the first resonant frequency, Determining the second resonant frequency of the end effector of the ultrasonic instrument, The temperature is determined by applying the second resonant frequency and the coefficient to the second temperature model, The method according to Embodiment 1, including the method described above. (7) Determining the impedance of the end effector based on the input current of the ultrasonic device, Determining a corrected resonant frequency based on the impedance and the second resonant frequency, It further includes, Determining the temperature of the end effector based on the output of the second temperature model includes applying the corrected resonant frequency as an input to the second temperature model. The method according to Embodiment 6. (8) Further including determining the input current supplied to the ultrasonic instrument, and determining whether the end effector is in a heated state or a cooled state, When the input current exceeds the current threshold, it is determined that the end effector is in the heated state, When the input current is less than the current threshold, it is determined that the end effector is in the cooling state, The method according to Embodiment 1, including the method described above. (9) Determining the impedance of the end effector based on the input current, In response to determining that the impedance is below a threshold, it is determined that the end effector is in the cooling state while it is in the air, In response to determining that the impedance exceeds the threshold, it is determined that the end effector is in the cooling state while in contact with the object, The method according to embodiment 8, further comprising: (10) A surgical system, An ultrasonic instrument having an end effector, The display and Processor and A memory having instructions, wherein, when executed by the processor, the instructions are transmitted to the surgical system. Determine the resonant frequency of the end effector. The end effector is then used to determine whether it is in a heated state or a cooled state. In response to determining that the end effector is in the heated state, the temperature of the end effector is estimated based on the output of a first temperature model having an input based on the resonant frequency. In response to determining that the end effector is in the cooling state, the temperature of the end effector is estimated based on the output of a second temperature model having an input based on the resonant frequency. A notification including the estimated temperature is displayed on the display. Memory and A surgical system equipped with [a specific feature / feature].

[0145] (11) The resonance frequency is a first resonance frequency at the start time when the end effector enters the heated state or the cooled state, and the memory is The starting temperature of the end effector at the aforementioned start time is determined, The second resonant frequency of the end effector is determined in the time following the start time. There are further orders for this, The temperature is estimated based on the starting temperature, the first resonant frequency, and the second frequency. The surgical system described in Embodiment 10. (12) In response to the determination that the end effector is in the heated state, the command for estimating the temperature is: The temperature change of the end effector is determined based on the difference between the first resonant frequency and the second frequency. By combining the aforementioned temperature change and the aforementioned starting temperature, A surgical system according to embodiment 11, comprising instructions for the purpose of performing the procedure. (13) In response to determining that the end effector is in the cooling state, the instruction for estimating the temperature is: Determine whether the end effector is air-cooled or contact-cooled. In response to determining that the end effector is air-cooled, the temperature of the end effector is estimated based on the output of the first cooling temperature model. In response to determining that the end effector is being contact-cooled, the temperature of the end effector is estimated based on the output of a second cooling temperature model. Equipped with instructions for, The first cooling temperature model described above is a polynomial model, and the second cooling temperature model described above is an exponential model. The surgical system described in Embodiment 10. (14) The resonant frequency is the first resonant frequency, and the instruction for estimating the temperature of the end effector based on the output of the second temperature model is: Based on the first resonance frequency, the model coefficients of the second temperature model are determined. The second resonant frequency of the end effector of the ultrasonic instrument is determined. The temperature is determined by applying the second resonant frequency and the coefficient to the second temperature model. A surgical system according to embodiment 10, comprising instructions for the following. (15) The memory is The impedance of the end effector is determined based on the input current of the ultrasonic device. A corrected resonant frequency is determined based on the impedance and the second resonant frequency. There are further orders for this, The surgical system according to Embodiment 14, wherein the instruction for determining the temperature of the end effector based on the output of the second temperature model includes an instruction for applying the corrected resonant frequency as an input to the second temperature model.

[0146] (16) A non-temporary machine-readable medium having instructions, wherein, when executed by the processor of the surgical system, the surgical system Determine the resonant frequency of the end effector of the ultrasonic instrument. The end effector of the ultrasonic device is to be determined to be in a heated state or a cooled state. In response to determining that the end effector is in the heated state, the temperature of the end effector is estimated based on the output of a first temperature model having an input based on the resonant frequency. In response to determining that the end effector is in the cooling state, the temperature of the end effector is estimated based on the output of a second temperature model having an input based on the resonant frequency. To display a notification based on the estimated temperature, Non-temporary machine-readable media. (17) The resonant frequency is a first resonant frequency at the start time when the end effector enters the heated state or the cooled state, and the non-transient machine-readable medium is The starting temperature of the end effector at the aforementioned start time is determined, The second resonant frequency of the end effector of the ultrasonic device is determined at a time following the aforementioned start time. There are further orders for this, The temperature is estimated based on the starting temperature, the first resonant frequency, and the second frequency, in the non-transient machine-readable medium according to Embodiment 16. (18) In response to determining that the end effector is in the heated state, the instruction for estimating the temperature is: The temperature change of the end effector is determined based on the difference between the first resonant frequency and the second frequency. By combining the aforementioned temperature change and the aforementioned starting temperature, A non-temporary machine-readable medium according to embodiment 17, comprising instructions for the purpose of... (19) In response to determining that the end effector is in the cooling state, the instruction for estimating the temperature is: Determine whether the end effector is air-cooled or contact-cooled. In response to determining that the end effector is air-cooled, the temperature of the end effector is estimated based on the output of the first cooling temperature model. In response to determining that the end effector is being contact-cooled, the temperature of the end effector is estimated based on the output of a second cooling temperature model. A non-temporary machine-readable medium according to embodiment 16, comprising instructions for the purpose of... (20) The resonant frequency is a first resonant frequency, and the instruction for estimating the temperature of the end effector based on the output of the second temperature model is: Based on the first resonance frequency, the model coefficients of the second temperature model are determined. The second resonant frequency of the end effector of the ultrasonic instrument is determined. The temperature is determined by applying the second resonant frequency and the coefficient to the second temperature model. A non-temporary machine-readable medium according to embodiment 16, comprising instructions for the purpose of...

Claims

1. A surgical system, An ultrasonic instrument having an end effector, The display and Processor and A memory having instructions, wherein, when executed by the processor, the instructions are transmitted to the surgical system. Determine the resonant frequency of the end effector. The end effector is then used to determine whether it is in a heated state or a cooled state. In response to determining that the end effector is in the heated state, the temperature of the end effector is estimated based on the output of a first temperature model having an input based on the resonant frequency. In response to determining that the end effector is in the cooling state, the temperature of the end effector is estimated based on the output of a second temperature model having an input based on the resonant frequency. A notification including the estimated temperature is displayed on the display. Memory and A surgical system equipped with [a specific feature / feature].

2. The aforementioned resonant frequency is a first resonant frequency at the start time when the end effector enters the heated state or the cooled state, and the memory is The starting temperature of the end effector at the aforementioned start time is determined, The second resonant frequency of the end effector is determined in the time following the start time. There are further orders for this, The temperature is estimated based on the starting temperature, the first resonant frequency, and the second frequency. The surgical system according to claim 1.

3. In response to determining that the end effector is in the heated state, the command for estimating the temperature is: The temperature change of the end effector is determined based on the difference between the first resonant frequency and the second frequency. By combining the aforementioned temperature change and the aforementioned starting temperature, The surgical system according to claim 2, comprising instructions for the following:

4. In response to determining that the end effector is in the cooling state, the instruction for estimating the temperature is: Determine whether the end effector is air-cooled or contact-cooled. In response to determining that the end effector is air-cooled, the temperature of the end effector is estimated based on the output of the first cooling temperature model. In response to determining that the end effector is being contact-cooled, the temperature of the end effector is estimated based on the output of a second cooling temperature model. Equipped with instructions for, The first cooling temperature model is a polynomial model, and the second cooling temperature model is an exponential model. The surgical system according to claim 1.

5. The aforementioned resonant frequency is a first resonant frequency, and the instruction for estimating the temperature of the end effector based on the output of the second temperature model is: Based on the first resonance frequency, the model coefficients of the second temperature model are determined. The second resonant frequency of the end effector of the ultrasonic instrument is determined. The temperature is determined by applying the second resonant frequency and the coefficient to the second temperature model. The surgical system according to claim 1, comprising instructions for the following:

6. The aforementioned memory is The impedance of the end effector is determined based on the input current of the ultrasonic device. A corrected resonant frequency is determined based on the impedance and the second resonant frequency. There are further orders for this, The surgical system according to claim 5, wherein the instruction for determining the temperature of the end effector based on the output of the second temperature model includes an instruction for applying the corrected resonant frequency as an input to the second temperature model.

7. A non-temporary machine-readable medium having instructions, wherein, when executed by the processor of a surgical system, the surgical system Determine the resonant frequency of the end effector of the ultrasonic instrument. The end effector of the ultrasonic device is to be determined to be in a heated state or a cooled state. In response to determining that the end effector is in the heated state, the temperature of the end effector is estimated based on the output of a first temperature model having an input based on the resonant frequency. In response to determining that the end effector is in the cooling state, the temperature of the end effector is estimated based on the output of a second temperature model having an input based on the resonant frequency. To display a notification based on the estimated temperature, Non-temporary machine-readable media.

8. The aforementioned resonant frequency is a first resonant frequency at the start time when the end effector enters the heated state or the cooled state, and the non-transient machine-readable medium is The starting temperature of the end effector at the aforementioned start time is determined, The second resonant frequency of the end effector of the ultrasonic device is determined at a time following the aforementioned start time. There are further orders for this, The non-transient machine-readable medium according to claim 7, wherein the temperature is estimated based on the starting temperature, the first resonant frequency, and the second frequency.

9. In response to determining that the end effector is in the heated state, the instruction for estimating the temperature is: The temperature change of the end effector is determined based on the difference between the first resonant frequency and the second frequency. By combining the aforementioned temperature change and the aforementioned starting temperature, A non-temporary machine-readable medium according to claim 8, comprising instructions for the purpose of:

10. In response to determining that the end effector is in the cooling state, the instruction for estimating the temperature is: Determine whether the end effector is air-cooled or contact-cooled. In response to determining that the end effector is air-cooled, the temperature of the end effector is estimated based on the output of the first cooling temperature model. In response to determining that the end effector is being contact-cooled, the temperature of the end effector is estimated based on the output of a second cooling temperature model. A non-temporary machine-readable medium according to claim 7, comprising instructions for the purpose of:

11. The aforementioned resonant frequency is a first resonant frequency, and the instruction for estimating the temperature of the end effector based on the output of the second temperature model is: Based on the first resonance frequency, the model coefficients of the second temperature model are determined. The second resonant frequency of the end effector of the ultrasonic instrument is determined. The temperature is determined by applying the second resonant frequency and the coefficient to the second temperature model. A non-temporary machine-readable medium according to claim 7, comprising instructions for the purpose of:

12. It is a method, Determining the resonant frequency of the end effector of an ultrasonic instrument, To determine whether the end effector of the ultrasonic device is in a heated state or a cooled state, In response to determining that the end effector is in the heated state, the temperature of the end effector is estimated based on the output of a first temperature model having an input based on the resonant frequency. In response to determining that the end effector is in the cooling state, the temperature of the end effector is estimated based on the output of a second temperature model having an input based on the resonant frequency. To provide a notification based on the estimated temperature, Methods that include...

13. The aforementioned resonant frequency is a first resonant frequency at the start time when the end effector enters the heated state or the cooled state, and the method is as follows: Determining the start temperature of the end effector at the aforementioned start time, Determining the second resonant frequency of the end effector of the ultrasonic device at a time following the aforementioned start time, It further includes, The temperature is estimated based on the starting temperature, the first resonant frequency, and the second frequency. The method according to claim 12.

14. In response to determining that the end effector is in the heated state, estimating the temperature is: The temperature change of the end effector is determined based on the difference between the first resonant frequency and the second resonant frequency, Combining the aforementioned temperature change with the aforementioned starting temperature, The method according to claim 13, including the method described in claim 13.

15. In response to determining that the end effector is in the cooling state, estimating the temperature is: To determine whether the end effector is air-cooled or contact-cooled, In response to determining that the end effector is air-cooled, the temperature of the end effector is estimated based on the output of the first cooling temperature model, In response to determining that the end effector is being contact-cooled, the temperature of the end effector is estimated based on the output of a second cooling temperature model. The method according to claim 12, including the method described in claim 12.

16. The method according to claim 15, wherein the first cooling temperature model is a polynomial model and the second cooling temperature model is an exponential model.

17. The aforementioned resonant frequency is the first resonant frequency, and estimating the temperature of the end effector based on the output of the second temperature model is: Determining the model coefficients of the second temperature model based on the first resonant frequency, Determining the second resonant frequency of the end effector of the ultrasonic device, The temperature is determined by applying the second resonant frequency and the coefficient to the second temperature model, The method according to claim 12, including the method described in claim 12.

18. The impedance of the end effector is determined based on the input current of the ultrasonic device, Determining a corrected resonant frequency based on the impedance and the second resonant frequency, It further includes, Determining the temperature of the end effector based on the output of the second temperature model includes applying the corrected resonant frequency as an input to the second temperature model. The method according to claim 17.

19. The process further includes determining the input current supplied to the ultrasonic device and determining whether the end effector is in a heated or cooled state. When the input current exceeds the current threshold, it is determined that the end effector is in the heated state, When the input current is less than the current threshold, it is determined that the end effector is in the cooling state, The method according to claim 12, including the method described in claim 12.

20. The impedance of the end effector is determined based on the input current, In response to determining that the impedance is below a threshold, it is determined that the end effector is in the cooling state while it is in the air, In response to determining that the impedance exceeds the threshold, it is determined that the end effector is in the cooling state while in contact with the object, The method according to claim 19, further comprising:

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