Method and system for detecting liquid immersion of end effector of ultrasonic instrument

Abstract

A method performed by a surgical system. The method determines one or more characteristics of an end effector of the ultrasonic instrument and determines that the end effector is at least partially submerged within the liquid based on the determined one or more characteristics. In response, the method displays a notification on a display of the surgical system indicating that the end effector is at least partially submerged within the liquid.

Description

Technical Field

[0001] Various aspects of the present disclosure relate generally to surgical systems, and more particularly to surgical systems for detecting liquid immersion of ultrasonic instruments. Other aspects are also described. Background Art

[0002] Minimally invasive surgery (MIS) such as laparoscopic surgery uses techniques designed to reduce tissue damage during surgical procedures. Laparoscopic procedures typically require multiple small incisions to be made in the patient's body (e.g., in the abdomen), through which several surgical tools (such as endoscopes, knives, graspers, and needles) are then inserted into the patient's body. Gas is injected into the abdomen, which inflates the abdomen, thereby providing more space around the end of the tool, making it easier for the surgeon to see (via an endoscope) and manipulate tissue at the surgical site. MIS can be performed faster and with less fatigue for the surgeon using a surgical robotic system, in which a surgical tool is operably attached to the distal end of a robotic arm, and a control system actuates the arm and its attached tool. When the surgeon manipulates a handheld user input device (UID), the end of the tool will simulate its position and orientation motion. A surgical robotic system can have multiple surgical arms, one or more of which have an attached endoscope, and other surgical arms have attached surgical instruments for performing certain surgical actions.

[0003] Control inputs from a user (e.g., a surgeon or other operator) are captured via one or more user input devices and then translated into control of the robotic system. For example, when a surgical tool is positioned at a surgical site of a patient, a tool driver having one or more motors may actuate one or more degrees of freedom of the surgical tool in response to user commands. Summary of the invention

[0004] The surgical tools used in some MIS procedures are ultrasonic instruments that use ultrasonic vibrations at their tips to quickly generate heat for cutting and cauterizing tissue. The tip may include a knife that reaches a high temperature (e.g., greater than 300° C.) during a "heating" cycle in which the knife oscillates against the mass of tissue, thereby generating heat during the oscillation due to friction between the knife and the tissue. After reaching the high temperature, the knife can be used to cut a portion of the tissue while also sealing the remaining tissue. The use of tools during laparoscopic surgery reduces instrument changes and the number of instruments during the procedure by performing multiple tasks (e.g., cutting, cauterizing, etc. for dissection).

[0005] The present disclosure provides a laparoscopic surgical system that estimates the temperature of a blade of an ultrasonic instrument during a heating cycle and a cooling cycle of the blade. Specifically, when the instrument is used to dissect tissue, the system can activate the instrument by providing power (e.g., in response to receiving a user input from an operator, such as pressing on a pedal or button) to oscillate the blade of the instrument. While the instrument is active in this "high power" state, the system can determine the temperature of the blade based on one or more characteristics of the instrument (e.g., input voltage, input current, resonant frequency, etc.). After the heating cycle is terminated (e.g., the operator releases the pedal), the system can enter a "low power" state (or cooling cycle) in which the ultrasonic instrument can draw less power (e.g., be provided with less current) to cause the blade to vibrate less than when the instrument is in the high power state. When in this low power state, the instrument may not draw enough power to generate frictional heat (e.g., because the blade vibrates in an excursion range lower than the excursion required to generate heat), but may have enough power to determine one or more characteristics of the instrument, such as the resonant frequency of the blade, which the system can use to estimate the temperature of the ultrasonic instrument when it cools. Thus, the system may provide the operator with (eg, continuous) temperature readings of the ultrasonic instrument between heating cycles and cooling cycles.

[0006] The temperature estimation of an ultrasonic instrument may be affected when the blade of the instrument contacts tissue and / or is immersed in a liquid (e.g., blood, saline, etc.). As described herein, the temperature estimation of the blade can be based on the resonant frequency of the blade. However, when the blade is immersed in a liquid and / or touches an object, the resonant frequency of the blade may change (e.g., due to increased stiffness of the blade). Therefore, the surgical system may not be able to effectively estimate the temperature of the end effector. Therefore, a surgical system is needed to detect the state of the end effector of an ultrasonic instrument (e.g., whether the end effector is immersed in a liquid and / or in contact with an object) to appropriately and effectively estimate the temperature of the end effector.

[0007] In addition, there is a need for a surgical system to notify (alert) an operator of the system when at least a portion of an end effector (e.g., a blade) is at least partially submerged in a liquid and / or in contact with an object. As described herein, once an ultrasonic instrument switches from a heating cycle to a cooling cycle, the blade may be too hot to touch tissue. However, during a surgical operation, the operator may have minimal visibility to the hot end effector. Therefore, the operator may not be able to visually discern whether the end effector is touching anything when the end effector is cooling.

[0008] The present disclosure provides a surgical system that detects and alerts an operator that an ultrasonic instrument is in contact with an object (e.g., tissue) and / or is at least partially immersed (submerged) in a liquid. Specifically, the system determines one or more characteristics of an end effector of an ultrasonic instrument (e.g., when the ultrasonic instrument is in a low power state and is cooling). For example, the characteristic may be the impedance of the end effector. The system determines that the end effector is at least partially immersed in a liquid (and / or in contact with an object such as tissue) based on one or more characteristics. In response, the system displays a notification on a display of the surgical system indicating that the end effector is immersed in a liquid (and / or in contact with an object). Therefore, the system is able to alert the operator to the status of the end effector so that the operator avoids contacting the object while the knife is still hot.

[0009] In one aspect, the one or more characteristics include an impedance of the end effector, wherein determining that the end effector is at least partially submerged includes determining that the impedance is above an impedance threshold. In another aspect, the one or more characteristics include a resonant frequency of the end effector, wherein determining that the end effector is at least partially submerged also includes determining that the resonant frequency is below a resonant frequency threshold. In some aspects, the system determines a type of liquid in which the end effector is at least partially submerged based on the one or more characteristics, wherein the notification indicates the type of liquid.

[0010] In one aspect, the one or more characteristics include an impedance of the end effector, wherein determining that the end effector is at least partially submerged includes determining that the impedance is above a first threshold, wherein in response to the impedance being above a second threshold that is greater than the first threshold, the system further determines that the end effector is in contact with the object while at least partially submerged within the liquid. In some aspects, the notification indicates that the end effector is in contact with the object while submerged in the liquid.

[0011] In another aspect, the system determines the temperature of the end effector and displays the temperature on the display when the end effector is in air, and replaces the temperature with an estimated temperature of the liquid in response to determining that the end effector is at least partially submerged. Thus, the surgical system can estimate and display the temperature of the end effector based on whether the blade is immersed in a liquid and / or in contact with an object.

[0012] The above summary does not include an exhaustive list of all aspects of the present disclosure. It is contemplated that the present disclosure includes all systems and methods that can be implemented by all suitable combinations of the various aspects summarized above and those disclosed in the detailed description below and specifically pointed out in the claims. Such combinations may have specific advantages not specifically recited in the above summary. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Various aspects are illustrated in the figures of the accompanying drawings by way of example and not limitation, wherein like reference numerals indicate similar elements. It should be noted that references to "one" or "an" aspect of the present disclosure are not necessarily to the same aspect, and that they refer to at least one. In addition, for the sake of brevity and to reduce the total number of drawings, a given drawing may be used to illustrate features of more than one aspect, and not all elements in the drawings may be required for a given aspect.

[0014] Figure 1 A pictorial view of an example surgical system in a surgical setting is shown.

[0015] Figure 2 A pictorial view of an ultrasonic instrument and generator according to one aspect of the present disclosure is shown.

[0016] Figure 3 Shows Figure 2 The end effector of an ultrasonic instrument.

[0017] Figure 4 is a block diagram of a surgical system according to one aspect.

[0018] Figure 5 is a flow chart of a process for determining whether an end effector of an ultrasonic instrument is at least partially submerged in a liquid and / or in contact with an object.

[0019] Figure 6 Several stages of a display of a surgical system are shown, the display being display of actions performed by an end effector of an ultrasonic instrument and showing notifications based on whether the end effector is submerged in a liquid and / or in contact with an object.

[0020] Figure 7 is a flow chart of a process for estimating a temperature of an end effector based on detecting that an ultrasonic instrument is at least partially submerged in a liquid. DETAILED DESCRIPTION

[0021] Several aspects of the present disclosure are now explained with reference to the accompanying drawings. Whenever the shapes, relative positions and other aspects of the parts described in a given aspect are not explicitly defined, the scope of the present disclosure is not limited to the parts shown, which are shown for illustrative purposes only. In addition, although many details are set forth, it should be understood that some aspects can be practiced without these details. In other cases, well-known circuits, structures and technologies are not shown in detail to avoid obscuring the understanding of this specification. In addition, unless the meaning is clearly contrary, all ranges listed herein are deemed to include the endpoints of each range.

[0022] Figure 1A pictorial view of an example (e.g., laparoscopic) surgical system (which may be referred to hereinafter as a "system") 1 in a surgical setting is shown. System 1 includes a user console 2, a control tower 3, and one or more surgical robotic arms 4 at a surgical robotic table (surgical table or surgical platform) 5. In one aspect, arm 4 may be mounted to a Figure 1 The example of the operating table or bed on which the patient is located is shown. In one aspect, at least some of the arms 4 may be configured differently. For example, at least some of the arms may be mounted on a ceiling, a side wall, or another suitable structural support (such as a cart separate from the operating table). The system 1 can be combined with any number of devices, tools, or accessories for performing surgery on the patient 6. For example, the system 1 may include one or more surgical tools (instruments) 7 for performing a surgical operation (surgical procedure). The surgical tool 7 can be an end effector attached to the distal end of the surgical arm 4 for performing a surgical procedure.

[0023] Each surgical tool 7 can be manually manipulated, robotically manipulated, or both during a surgical procedure. For example, a surgical tool 7 can be a tool for entering, viewing, or manipulating the internal anatomical structure of a patient 6. On the one hand, a surgical tool 7 is a gripper that can grasp the patient's tissue. The surgical tool 7 can be manually controlled by a bedside operator 8; or it can be robotically controlled via actuation of a surgical robot arm 4 to which it is attached. For example, when manually controlled, an operator can (e.g., physically) hold a portion of the tool (e.g., a handle), and can manually control the tool by moving the handle and / or pressing one or more input controls (e.g., buttons) on the tool (e.g., the handle of the tool). On the other hand, when robotically controlled, the surgical system can manipulate the surgical tool based on user input (e.g., received via a user console 2, as described herein).

[0024] Generally, a remote operator 9 (such as a surgeon or other operator) may use the user console 2 to remotely manipulate the arm 4 and / or attached surgical tools 7, for example during a remote operation. The user console 2 may be located in the same operating room as the rest of the system 1, such as in a remote operating room. Figure 1As shown. However, in other environments, the user console 2 may be located in an adjacent or nearby room, or it may be located 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 controls (or foot pedals) 13, one or more (handheld) user input devices (UID) 14, and at least one display 15. The display is configured to display a view of a surgical site within a patient 6, for example. The display may be configured to display image data (e.g., static images and / or videos). In one aspect, the display may be any type of display, such as a liquid crystal display (LCD), a light emitting diode (LED) display, an organic LED (OLED) display, etc. In some aspects, the display may be a 3D immersive display for displaying a 3D (surgery) presentation. For example, during a surgical procedure, one or more endoscopic cameras may capture image data of a surgical site, and the display presents the image data to the user in 3D. In one aspect, the 3D display may be an autostereoscopic display that provides a 3D perception to the user without the need for special glasses. As another example, the 3D display may be a stereoscopic display that provides 3D perception through the use of glasses (eg, via active shutters or polarization).

[0025] On the other hand, the display 15 may be configured to display at least one graphical user interface (GUI) that can provide information and / or interactive content, thereby assisting the user in performing surgical procedures through 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 endoscopic cameras, as described herein. On the other hand, the GUI may include selectable UI items that, when manipulated by the user, enable the system to perform one or more operations. For example, the GUI may include UI items as interactive content to switch control between robot arms. In one aspect, in order to interact with the GUI, the system may include an input device (such as a keyboard, a mouse, etc.). On the other hand, the user may use UID14 to interact with the GUI. For example, the user may manipulate the UID to navigate through the GUI (e.g., using a cursor), and to make a selection, the cursor may hover over the UI item and manipulate the UID (e.g., select a control or button). In some aspects, the display may be a touch-sensitive display screen. In this case, the user may perform a selection by navigating and selecting via the touch display. In some aspects, any method may be used to navigate and / or select UI items.

[0026] As shown, the teleoperator 9 sits in the chair 10 and views the user display 15 while manipulating the foot control 13 and the handheld UID 14 to remotely control one or more of the arm 4 and the surgical tool 7 (which is mounted on the distal end of the arm 4).

[0027] In some variations, the bedside operator 8 can also operate the system 1 in an "in bed" mode, where the bedside operator 8 (user) is now located on the side of the patient 6 and manipulates the robot-driven tools (the end effector attached to the arm 4) at the same time, for example, holding the handheld UID 14 and the manual laparoscopic tools with one hand. For example, the left hand of the bedside operator can manipulate the handheld UID to control the robotic components, while the right hand of the bedside operator can manipulate the manual laparoscopic tools. Therefore, in these variations, the bedside operator 8 can perform both robot-assisted minimally invasive surgery and manual laparoscopic surgery on the patient 6.

[0028] During the example procedure (surgical operation), the patient 6 is prepared for surgery and covered with a sterile drape in a sterile manner to achieve anesthesia. When the arm of the system 1 is in a stowed configuration or a withdrawn configuration, the initial access to the surgical site (to facilitate access to the surgical site) can be performed manually. Once the access is completed, the initial positioning or preparation of the system 1 (including its arm 4) can be performed. Then, the surgical operation continues, and the remote operator 9 at the user console 2 uses the foot control 13 and the UID 14 to manipulate various end effectors and possible imaging systems to perform the surgical operation. Manual assistance can also be provided at the operating bed or operating table by a bedside person (e.g., a bedside operator 8) wearing a sterile surgical gown, and the bedside person can perform tasks on one or more arms in the robot arm 4, such as retracting tissue, performing manual repositioning, and tool replacement. Non-sterile personnel may also be present to assist the remote operator 9 at the user console 2. When the procedure or surgical operation is completed, the system 1 and user console 2 may be configured or set to a state to facilitate completion of post-operative procedures, such as cleaning or disinfection, and inputting or printing healthcare records via the user console 2 .

[0029] In one aspect, the remote operator 9 holds and moves the UID 14 to provide input commands to drive (move) one or more robot arm actuators 17 (or drive mechanisms) in the robotic system 1 for remote operation. The UID 14 may be communicatively coupled to the rest of the system 1, for example, via a console computer system 16 (or host). The UID 14 may generate a spatial state signal corresponding to the movement of the UID 14, such as the position and orientation of the handheld housing of the UID, and the spatial state signal may be an input signal to control the movement of the robot arm actuator 17. The system 1 may use a control signal derived from the spatial state signal to control the proportional movement of the actuator 17. In one aspect, the console processor of the console computer system 16 receives the spatial state signal and generates a corresponding control signal. Based on these control signals that control how the actuator 17 is powered to drive the segments or connectors of the arm 4, the movement of the corresponding surgical tool attached to the arm may simulate the movement of the UID 14. Similarly, interaction between the remote operator 9 and the UID 14 may generate, for example, a grasp control signal that causes the jaws of a grasper of the surgical tool 7 to close and grasp tissue of the patient 6 .

[0030] The system 1 may include several UIDs 14, wherein respective control signals are generated for each UID controlling the actuators and surgical tools (end effectors) of the respective arms 4. For example, the teleoperator 9 may move the first UID 14 to control the movement of an actuator 17 located in the left robotic arm, wherein the actuator responds by moving a link, gear, etc. in the arm 4. Similarly, the movement of the second UID 14 by the teleoperator 9 controls the movement of another actuator 17, which in turn drives other links, gears, etc. of the system 1. The system 1 may include a right arm 4 fixed to a bed or table on the right side of a patient, and a left arm 4 located on the left side of the patient. The actuator 17 may include one or more motors that are controlled so that they drive the joint of the arm 4 to rotate, for example, to change the orientation of an endoscope or gripper of a surgical tool 7 attached to the arm relative to the patient. The movement of several actuators 17 in the same arm 4 may be controlled by a spatial state signal generated from a particular UID 14. The UID 14 may also control the movement of the respective surgical tool gripper. For example, each UID 14 may generate a corresponding grasping signal to control the movement of an actuator (eg, a linear actuator) that opens or closes the jaws of a grasper at the distal end of the surgical tool 7 to grasp tissue within the patient 6 .

[0031] In some aspects, the communication between the surgical robotic table 5 and the user console 2 can be performed through a control tower 3, which can translate user commands received from the user console 2 (and more specifically from the console computer system 16) into robotic control commands transmitted to the arm 4 on the surgical table 5. The control tower 3 can also transmit status and feedback from the surgical table 5 back to the user console 2. The communication connection between the surgical table 5, the user console 2 and the control tower 3 can be via a wired link (e.g., optical fiber) and / or a wireless link, using any suitable data communication protocol in a variety of wireless data communication protocols, such as the Bluetooth protocol. Any wired connection can optionally be built into the floor and / or wall or ceiling of the operating room. The system 1 can provide video output to one or more displays (including displays in the operating room and remote displays accessible via the Internet or other networks). The video output or feed can also be encrypted to ensure privacy, and all or part of the video output can be saved to a server or electronic health record system.

[0032] Figure 2 A pictorial view of an ultrasonic instrument 20 and a generator 25 according to one aspect of the present disclosure is shown. As shown, the ultrasonic instrument is a handheld laparoscopic tool that is configured to perform ultrasonic surgical operations (e.g., cutting and sealing tissue) based on manual operation of the instrument by an operator (e.g., a surgeon) (e.g., manual operation of a handle 21). For example, during a laparoscopic (or endoscopic) surgical procedure, a small incision is made in a patient, and the ultrasonic instrument can be inserted into a cavity of the patient (e.g., insufflating the cavity with a gas), where an end effector can be used by the operator to manipulate tissue and perform surgical operations (e.g., cutting and / or cauterization, etc.). The ultrasonic instrument is connected to a generator (e.g., via a cable) (as shown), which enables the ultrasonic instrument to operate in one or more power states, as described herein.

[0033] According to aspects of the subject technology, an ultrasonic instrument includes a handle (eg, including a tool driver) 21, a shaft (or cannula) 22, and an end effector 23 loaded into the cannula (eg, which may be coupled to the shaft of the instrument).

[0034] The handle 21 is arranged to be held by an operator and allows the operator to manipulate the ultrasonic instrument (e.g., the end effector 23 of the ultrasonic instrument) 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 allow the operator to control the ultrasonic instrument. For example, the instrument may include a trigger that, when pulled by one or more fingers of the user while being held, generates a control signal that allows the user to control the end effector of the instrument (and / or control a portion of the surgical system). Specifically, the trigger may be arranged to manipulate the end effector (e.g., by adjusting Figure 3 ). In another aspect, the handle may include one or more inputs for changing the power state of the instrument. More about the power state of the instrument is described herein.

[0035] As described herein, the handle may include a tool driver arranged to drive the end effector 23 of the ultrasonic instrument. Specifically, the tool driver may include a (e.g., linear) motor or actuator arranged to vibrate (or oscillate) the end effector (e.g., the blade of the end effector) at one or more frequencies (e.g., at very high (ultrasonic) frequencies and at low frequencies). In some aspects, the tool driver is configured to vibrate the end effector so that a portion of the end effector (e.g., the blade) moves back and forth along one or more axes. Specifically, the tool driver may vibrate the end effector at one or more offsets, wherein at each offset, the end effector (e.g., the blade of the end effector) may be displaced at a different distance from a starting (or starting) position. More information about how the end effector vibrates is described herein. In another aspect, the tool driver may include an ultrasonic transducer configured to vibrate the end effector according to an input voltage / input current (e.g., applied by a generator 25).

[0036] As described so far, the ultrasonic instrument may include an end effector 23 and a handle (which includes a tool driver) 21. Specifically, the instrument has a handle 21, a shaft 22 coupled to the distal end of the handle, and an end effector 23 coupled to the distal end of the shaft. In this case, the ultrasonic instrument as referred to herein may be an end effector that can be coupled to the handle (e.g., a tool driver coupled to the handle via the shaft 22). In one aspect, the ultrasonic instrument (e.g., the end effector of the ultrasonic instrument) is detachable from the handle (and removably coupled to the handle). In some aspects, the shaft receives and guides the knife (e.g., the shaft of the knife) so as to be coupled to the instrument.

[0037] As described herein, the surgical system 1 includes an ultrasonic instrument 20 configured to generate heat based on vibrations of its end effector 23. In another embodiment, the instrument can be any type of energy (e.g., endoscopic, laparoscopic, etc.) tool designed to generate heat.

[0038] As currently described, the ultrasonic instrument 20 can be a handheld laparoscopic instrument that can be manually held and manipulated by an operator. In another embodiment, the instrument can be part of a surgical robotic arm. Specifically, the ultrasonic instrument can be coupled to the robotic arm and powered by a generator, as described herein. For example, the ultrasonic instrument can be coupled to the distal end of the robotic arm (e.g., Figure 1The robotic arm 4 includes several components that allow the robotic arm to be controlled by an operator. For example, the surgical robotic arm 4 may include a plurality of connectors and a plurality of braked joint modules for actuating the plurality of connectors relative to each other. The joint modules may include various joint types, such as pitch joints or roll joints, which may substantially constrain the movement of adjacent connectors around certain axes relative to other axes. The plurality of joint modules of the robotic arm 4 may be actuated to position and orient an ultrasonic instrument for robotic surgery. In one embodiment, the ultrasonic instrument may be coupled to the distal end via a tool driver arranged to actuate the end effector 23 of the instrument.

[0039] Where the ultrasonic instrument is coupled to a robotic arm, movement and operation of the ultrasonic instrument may be performed via one or more user controls coupled to the surgical system (e.g., UID, foot pedal, etc.). For example, the UID may be arranged to open / close the gripper 23 of the ultrasonic instrument and / or may be arranged to adjust the spatial position (in space) of the gripper based on user input (e.g., the position of the UID).

[0040] Steering Figure 3 , the figure shows Figure 2The end effector 23 of the ultrasonic instrument. Specifically, the figure shows that the end effector is a gripper (or gripping device) comprising a knife (or end) 30 as a jaw and an articulated arm (or jaw) 31 rotatably coupled to a joint (or robot wrist) 32, which is coupled to the distal end of the shaft. On the other hand, the end effector 23 (e.g., the joint 32 of the end effector) can be a part of a portion (distal end) of the shaft 22. In one aspect, the gripper (or part of the gripper) is received by the shaft 22. For example, the knife can be received (and extended) through the shaft and arranged to be coupled to a tool driver (e.g., handle 21) at (or toward) the proximal end of the shaft. Therefore, as shown in the figure, the knife extends through the shaft (as shown in dotted lines), wherein a portion of the knife (e.g., the end) extends out of the shaft 22 and into the environment. Inside the shaft are two buffers 33, which are arranged between the portion of the knife extending through the shaft and the shaft (e.g., the inside of the shaft). In one aspect, the buffer can be designed to prevent the knife from contacting the inside of the shaft (e.g., when the knife vibrates back and forth). In one aspect, during operation (when the knife oscillates), the knife may (at least partially) contact (e.g., touch) the buffer. On the other hand, when the knife vibrates, the inner portion of the knife may not contact the buffer (at least one of the buffers). On the other hand, the knife may inadvertently contact at least one buffer. For example, during a surgical operation, an object may contact the shaft, causing the inner portion of the knife to shift (or move) toward the buffer (due to the impact of the object), thereby causing the knife to contact the buffer. On the other hand, the shaft may not include a buffer. On the other hand, the knife 30 may be connected to the shaft 22 (e.g., a portion of the shaft 22) (e.g., at the distal end of the shaft). Therefore, the inner portion of the shaft as shown in dotted lines may be connected to the knife 30.

[0041] The articulated arm 31 is rotatably coupled to the shaft 22 (at the joint 32), and the articulated arm is arranged to rotate about a rotation (Z) axis (e.g., in the Z direction). Specifically, the gripper can be arranged to open and close based on the rotational position of the articulated arm about the rotational axis of the joint relative to the knife (and / or the shaft). For example, the gripper is arranged to open (or be in an open position) when the articulated arm is rotated away from the knife (e.g., by a threshold distance). When in this position, the end effector can be oriented so that an object (such as tissue) can be set between the knife and the articulated arm (e.g., by moving the end effector around the object). When the articulated arm is rotated toward the knife (e.g., within a threshold distance), the gripper can be closed (or in a closed position), so that the gripper can grasp the object between the knife and the articulated arm. As described herein, the articulated arm can be arranged to apply pressure against the grasped object (e.g., squeeze the object between the jaws) in order to grasp the object and / or perform dissection on the object. In another aspect, the articulated arm 31 can be rotatably coupled to (a portion of) the knife. In one aspect, the knife 30 and the articulated arm can be received by an axis so that the arm (and / or the knife) is coupled to another axis passing through the axis 22.

[0042] As described herein, the knife 30 is the jaws of the gripper. Specifically, the knife is a jaw that cannot rotate relative to the end effector (e.g., around the Z axis). The knife can be arranged to vibrate along the longitudinal (Y) axis of the knife (in the Y direction) to generate heat when the ultrasonic instrument is in a high power state (or mode). Specifically, the knife can be driven (e.g., by a tool driver of the handle 21) to move back and forth (e.g., linearly) along the longitudinal axis of the end effector (and through the axis, as described herein) so that the knife 30 is repeatedly displaced at a certain (e.g., constant) frequency. Specifically, the knife can vibrate (e.g., reciprocate back and forth) on an offset (or displacement), wherein the knife moves a certain distance from a starting position (e.g., forward or away from the end effector) and then moves back the distance. In one aspect, the offset can be the distance that the knife moves from the starting position to the extended position. On the other hand, the offset can be the distance that the knife moves forward and backward.

[0043] As described herein, the knife can generate frictional heat when it vibrates against an object. Specifically, when the gripper squeezes tissue between the two jaws 30 and 31, the knife can come into contact with the tissue and can vibrate against the tissue. When the knife vibrates, the end effector can cut and / or cauterize the tissue, as described herein. In one aspect, the knife can vibrate differently (e.g., at different offsets) based on the power state of the ultrasonic instrument (e.g., how much power the ultrasonic instrument provides). More information about the vibrating knife and the power state of the ultrasonic instrument is described herein.

[0044] As described so far, the end effector 23 can be a gripper. On the other hand, the end effector can be any type of tool that can be designed to be manipulated by an ultrasonic instrument (e.g., the handle 21 of an ultrasonic instrument). For example, the end effector can be an endoscope, a stapler, etc.

[0045] Back to Figure 2 , the generator 25 is configured to control the ultrasonic instrument and provide power to the ultrasonic instrument to control (e.g., heat) the end effector 23 while the instrument is coupled to the generator and used by the operator (e.g., to manipulate tissue and / or perform one or more surgical tasks on tissue during laparoscopic surgery, such as to cut and seal blood vessels and / or cut, grasp and dissect tissue). Specifically, the generator can provide power to the ultrasonic instrument so that the surgical system 1 (e.g., the ultrasonic instrument of the surgical system) can operate in one of one or more power states. For example, the generator can provide power to the instrument so that the ultrasonic instrument is in a "high power" state (or "heating cycle"), in which the instrument draws power (or current) from the generator (e.g., at a specific voltage) to cause the end effector 23 to generate heat. For example, the generator can provide a (e.g., first) current (or input current) to a handle of the ultrasonic instrument (e.g., a tool driver of the handle), which can use the current to drive the blade 30 to vibrate (or oscillate) at a (first) offset (and at a specific frequency). When the blade of the end effector vibrates upward against an object (such as tissue) at this offset, friction heat may be generated by the end effector, as described herein. In another aspect, the ultrasonic instrument may be arranged to operate in a "low power" state (or "cooling cycle"), in which the ultrasonic instrument no longer draws (sufficient or as much) power provided by the generator, while the instrument is in a high power state to heat the end effector. Specifically, when in such a state, the generator may be configured to provide less power to the ultrasonic instrument than the power provided by the generator when the instrument is in the high power state, so that the end effector does not generate heat (e.g., when in contact with the object). Specifically, the generator may provide a current (e.g., a second current) to the ultrasonic instrument that is less than the (first) current provided by the generator when the instrument is operating in the high power state, and thus this does not cause the end effector to generate heat (or as much heat as when the ultrasonic instrument is in the high power state). Therefore, once the ultrasonic instrument enters the low power state from the high power state, the ultrasonic instrument may begin to cool. Eventually, if maintained in the low power state, the ultrasonic instrument will drop to (at least) a threshold temperature (e.g., room temperature). In one aspect, the second current may be less than a predefined threshold current. In one aspect, in the low power state, the blade may vibrate at the same frequency as in the high power state. In another aspect, the blade may vibrate within a tolerance frequency range.

[0046] Due to the lower current provided to the instrument when in the low power state, the blade of the end effector may be driven differently by the tool driver 21 than when the instrument is in the high power state. Specifically, the blade may vibrate at an offset different from the offset at which the blade vibrates when the instrument is in the high power state. For example, when in the high power state, the blade may vibrate at a first (e.g., high) offset, which may cause the blade to generate heat when pressed against an object, while when in the low power state, the blade may vibrate at a second (lower) offset, which may be less than the first offset (e.g., the blade is less displaced along the longitudinal axis than in the first offset). In some aspects, the second offset may be less than a minimum threshold (e.g., if the blade would vibrate at the minimum threshold, the blade would generate heat at the minimum threshold). In one aspect, the end effector may not generate frictional heat when vibrating at the lower offset and when vibrating upward against an object (e.g., when the gripper squeezes the object) (such as a blood vessel). In one aspect, the resonant frequency is maintained within a tolerance range regardless of which power state the instrument is operated in.

[0047] In one aspect, the difference in vibration of the end effector may be based on the amount of power drawn by the ultrasonic instrument when in different states. For example, the offset of the blade's displacement when it oscillates may be based on the power drawn by the instrument (e.g., proportional to the power), whereby more power drawn by the instrument may cause the blade to vibrate at a high offset. Conversely, when the ultrasonic instrument is in a low-power state, the instrument may draw less power, which causes the blade to vibrate less (compared to when the instrument is in a low-power state). Due to oscillation at a smaller displacement, the blade may not generate frictional heat (e.g., when in contact with tissue). On the other hand, the blade may generate some frictional heat when in a low-power state and in contact with an object, but may be less than the heat generated when the instrument is in a high-power state. In this case, such generated frictional heat may not be sufficient to cut and / or seal tissue. In some aspects, due to operating in a low-power state, the end effector of the ultrasonic instrument may enter a cooling cycle, whereby the heat generated by the end effector when the instrument is in a high-power state dissipates (e.g., within a period of time). On the other hand, when in this low-power state, the blade may not vibrate (e.g., the tool driver may not drive the blade).

[0048] In one aspect, the system may enter (or operate in) at least one of the power states based on user input (e.g., received by the generator 25). Specifically, the generator may provide power to the ultrasonic instrument based on receiving user input into one or more input devices (e.g., input into a foot pedal, a UID controlled by an operator and communicatively coupled to the system 1, and / or input at the handle 21 of the ultrasonic instrument). The power provided based on the user input may place the ultrasonic instrument in a high power state, wherein the ultrasonic instrument draws power from the generator to heat the end effector 23 (e.g., the blade 30 of the end effector). For example, when the generator receives a (first) user input (e.g., by the operator pulling or pressing a trigger on the handle 21), the generator may provide current to the ultrasonic instrument (e.g., the tool driver of the ultrasonic instrument), which uses the current to drive the end effector, as described herein. Thus, in the case where the trigger controls an articulated arm of the end effector, the generator is configured to provide current when the articulated arm is moved (e.g., moved toward the blade 30 by at least a threshold distance). In another aspect, the system may enter the low power state based on another (eg, second) user input (eg, receiving input from a different input device coupled to the generator, such as a foot pedal).

[0049] In some aspects, the ultrasonic instrument may be arranged to switch between a high power state and a low power state. As described herein, when the generator is receiving user input (e.g., the user pulls or presses the trigger on the handle), the instrument may operate in a high power state. The instrument may operate in a low power state in response to the generator not 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 (the generator may transition between these two states). In one aspect, the instrument may operate in a low power state while the operator is not actively using the instrument to perform ultrasonic instrument operations, as described herein. Specifically, the system may enter a low power state without user input being received in one or more input devices used by the operator to enter a high power state. However, once 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). On the other hand, the instrument may operate in a low power state in response to receiving user input (e.g., the user presses a button on the UID). On the other hand, 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) to notify the operator of the temperature, which may be high because the instrument has been operating in a high power state. Once the end effector cools to a certain temperature (e.g., equal to or below a predefined temperature), the generator can deactivate the instrument by stopping providing a lower current because at this temperature, if the end effector were to come into contact with tissue, the end effector may not cause thermal damage.

[0050] In one aspect, 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 pedal coupled to the generator), and in response, provide a maximum (allowable) amount of current to the ultrasonic instrument. The ultrasonic instrument may then drive the end effector at a maximum (e.g., predeterminable) excursion, which may cause the end effector to generate heat at a (first) high temperature. However, when the generator receives a second user input (e.g., from another pedal coupled to the generator), the generator may provide a lesser amount of current to the ultrasonic instrument. Thus, the ultrasonic instrument may draw less power to vibrate the end effector at a (second) lower excursion, which may be lower than the first excursion at which the blade vibrates in response to the first user input. However, the lower excursion may cause the end effector to heat at a lower temperature than the first temperature of the end effector when the ultrasonic instrument draws a larger current (in response to the generator receiving the first user input). By heating the end effector to different temperatures, different types of tissue may be cut and / or cauterized. For example, fattier tissue may require the end effector to be hotter (having a first temperature), while thinner (and less fat) tissue may require less heat (having a second temperature) in order to cut and / or cauterize the tissue. In another aspect, the generator can be configured to provide a current when in a high power state (e.g., to drive the end effector at a first high excursion).

[0051] As described herein, an ultrasonic instrument may be activated (e.g., operated in a high power state) based on whether the end effector is in a closed position to grasp an object (e.g., a tissue mass). For example, the ultrasonic instrument may be activated (e.g., by a user) so that the ultrasonic instrument may operate in a high power state to draw sufficient current to generate heat at the end effector. Specifically, the generator may activate the ultrasonic instrument to close the end effector (e.g., to move the articulated arm 31 within the distance of the knife 30) upon receiving user input. Once the user input is received to move the articulated arm, the generator may be configured to provide (e.g., sufficient) power to activate the instrument, as described herein. In some aspects, the generator may activate the instrument based on determining that the articulated arm and / or the knife are in contact with the object. For example, the ultrasonic instrument may include one or more sensors (e.g., force / pressure sensors) for detecting the presence of an object and / or detecting that the object is in contact with both arms. Specifically, the generator may enter a high power state when it is determined that the gripper is squeezing the object (based on the pressure detected from the sensor being above a threshold). Upon making this determination, the generator may provide a first current to oscillate the knife so that the knife generates heat. Once the pressure reading drops below a threshold (meaning the object has been released by the gripper), the generator may switch to a low power state.

[0052] In one aspect, a surgical system (e.g., a generator of a surgical system) may be configured to determine one or more characteristics of (an end effector of) an ultrasonic instrument when the instrument is in one or more power states. For example, the generator may be configured to keep track of (or monitor) characteristics such as an input voltage, input current, resonant state, resonant frequency, and / or (e.g., mechanical) impedance of an ultrasonic instrument (e.g., an end effector of an ultrasonic instrument). In one aspect, the generator may be configured to monitor at least some of these characteristics of the instrument when the instrument is operating in a high power state. Additionally, the system may be configured to determine (at least some of) these characteristics when the instrument is in a low power state (a cooling cycle or cooling period) due to the instrument drawing at least some power. For example, when in a low power state, the generator may determine the resonant frequency and impedance of the end effector (e.g., the blade 30 of the end effector). More information on determining these characteristics is described herein.

[0053] In one aspect, the surgical system can include additional components. For example, the system can include a cable connecting the generator to an ultrasonic instrument (e.g., an ultrasonic transducer configured to convert an electrical current drive signal into mechanical vibrations). In one aspect, the ultrasonic transducer can be connected to a waveguide that is connected to the blade 30 of the end effector 23.

[0054] As also shown, the generator 25 also includes a display 24, which is arranged to display information about the operation of the ultrasonic instrument. For example, the display can present temperature information, the current state of the ultrasonic instrument, and one or more characteristics described herein.

[0055] Figure 4 is a block diagram of a surgical system 1 according to one aspect. The system includes an ultrasonic instrument 20, a generator 25, a controller 40, a storage device 44, a display 15, and a speaker 43 (which can be a stand-alone speaker or part of the system's electronics, such as a user console 2). In one aspect, the system can include more or fewer elements, such as having more than one display and / or no speakers.

[0056] Examples of storage devices (e.g., non-transitory machine-readable storage media) may include read-only memory, random access memory, CD-ROM, DVD, magnetic tape, optical data storage devices, flash memory devices, and phase-change memory. Although the storage device is illustrated as being separate from the controller 40, the storage device may be part of the controller (e.g., internal memory).

[0057] In some aspects, the controller 40 can 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 aspect, the controller can 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 one aspect, the controller can include one or more electronic components (e.g., processors, memories, etc.) that are communicatively coupled on a single electronic device (such as a console computer 16) or across multiple devices (e.g., communicating on a wireless computer network). In some aspects, the controller can be part of a separate device, such as part of a remote server that communicates with one or more electronic devices. In another aspect, the controller can be part of the generator 25 (e.g., at least partially integrated therein). In this case, at least some other elements (e.g., speakers and displays) can also be part of the generator (integrated therein). Therefore, at least some of the operations performed by the controller described herein can be performed by the generator.

[0058] In one aspect, the controller is configured to perform temperature estimation operations for the surgical system 1 to determine the (e.g., real-time) temperature of an ultrasonic instrument (e.g., an end effector of an ultrasonic instrument) when the instrument is in one or more power states (e.g., in 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 determined when the instrument is in the low power state, such as the resonant frequency of the end effector (e.g., the blade of the end effector). The controller may determine the temperature using one or more temperature (predetermined) models (e.g., which may be stored in the storage device 44), whereby the temperature model (e.g., a polynomial model for a cooling period) may output an estimated temperature of the blade based on (in response to) the resonant frequency as input. For example, the controller may determine a normalized change in the resonant frequency (e.g., based on a difference between a (predetermined) baseline resonant frequency and a current resonant frequency reading) and determine one or more model coefficients (which are based on the resonant frequency at the beginning of the cooling period and a predetermined constant). The controller may estimate the temperature by applying the normalized change in the resonant frequency and the coefficients to the model as input, thereby generating a temperature estimate as output.

[0059] In one aspect, the controller can be configured to determine the temperature of the end effector using one or more (predetermined) models while the instrument is in a heating cycle or a cooling cycle. For example, the controller can be configured to estimate the temperature of the end effector by applying a change in resonant frequency (e.g., the difference between a baseline (or previously determined) resonant frequency and a current resonant frequency of the end effector) to a hysteresis model (stored in the storage device 44) that includes a hysteresis relationship between a change in the resonant frequency of the end effector and a corresponding temperature of the end effector. In another aspect, the controller can use any method to determine the temperature of the end effector while the ultrasonic instrument is operating in one or more power states.

[0060] In one aspect, (at least some of) the temperature estimation operations may be performed by the controller while the end effector is in a cooling period (e.g., when the instrument is in a low power state). In addition to (or in lieu of) being performed during the cooling period, the temperature estimation operations may be performed while the end effector is "in air," meaning that the blade is not (at least partially) immersed in a liquid and / or not in contact with an object (such as tissue). Specifically, as described herein, during laparoscopic surgery, one or more gases may be used to create a cavity within the abdomen of a patient. In this case, the temperature estimation operations may be performed while the end effector (the blade) is within the cavity but not touching tissue and / or liquid. In one aspect, the model used by the controller to estimate temperature may be predefined in a controlled environment (e.g., a laboratory) while the blade is in air (e.g., within a patient's body cavity but not touching an object and not immersed in liquid) during a surgical procedure.

[0061] However, when the knife touches an object and / or is at least partially immersed in a liquid, the model may be invalid (or inaccurate) in predicting (estimating) the temperature of the knife due to changes in the knife's characteristics (such as the knife's resonant frequency). For example, when the knife touches an object, its resonant frequency (or damped natural frequency, ω) increases due to the increase in the knife's stiffness k. d ) increases. Specifically, the natural frequency of attenuation can be considered as:

[0062]

[0063] where γ is the damping ratio, and ω n is the undamped natural frequency of the knife, which can be written as depending on the stiffness of the knife:

[0064]

[0065] Where m is the mass of the blade. In one aspect, m may include the mass of the blade and any object attached to the blade (e.g., residual tissue). The damping ratio may be written as:

[0066]

[0067] where b is the damping on the blade. Therefore, as k increases, ω n increases, so γ decreases, both of which make ω d Increase.

[0068] In contrast, when the blade is at least partially submerged (immersed) in the liquid (e.g., and not touching an object such as tissue), ω d may decrease due to an increase in the damping ratio γ, which is a result of an increase in the damping b. However, if the knife is immersed in a liquid and touches an object, ω d The temperature of the end effector of the apparatus may also change due to an increase in k and a decrease in b. Therefore, due to changes in the resonant frequency caused by touching an object and / or being immersed, the controller may not be able to accurately estimate the temperature using a model-based approach. Therefore, the controller may be configured to determine the state of the end effector of the instrument (e.g., whether it is touching an object and / or immersed in a liquid), and in response determine (or estimate) the (new) temperature of the end effector based on the determination. More content about estimating temperature is described herein.

[0069] In one aspect, at least some of the operations performed by the controller may be implemented in software (e.g., as instructions) stored in a memory of the surgical system (e.g., in a storage device and / or (internal) memory of the controller) and executed by the controller, and / or may be implemented by hardware logic structures. In one aspect, at least some of the operations performed by the controller may be performed each time the instrument enters a low-power state (or switches between two or more power states, such as between a high-power state to a low-power state).

[0070] As shown, the generator can receive user input (e.g., via one or more electronic devices coupled to the generator) for causing the generator to perform one or more operations. For example, a user input can be received via an ultrasonic instrument (e.g., when a user pulls on a trigger of a handle) to cause the generator to provide a current that causes the ultrasonic instrument to switch from a low-power state to a high-power state, as described herein.

[0071] Figure 5is a flow chart of a process 50 for determining a state of an end effector, such as whether the end effector 23 of the ultrasonic instrument 20 is at least partially submerged (immersed) in a liquid and / or in contact with an object (e.g., tissue). Specifically, at least some of these operations may be performed once and / or when the ultrasonic instrument is in one of the one or more power states described herein, such as a low power state. For example, at least some of the operations may be performed when (e.g., each time) the ultrasonic instrument switches from a high power state to a low power state, which may be based on user input, as described herein. In this case, the surgical system may perform these operations to determine the state of the end effector, such as whether it is touching an object and / or immersed in a liquid. In some aspects, at least some of the operations may be performed periodically while in the low power state to determine the state of the end effector when it is in a cooling cycle. In one aspect, the process may be performed by the surgical system 1. For example, each of the processes may also be performed by the controller 40. As another example, at least some of the operations may be performed by the generator 25 (e.g., by one or more processors of the generator). Therefore, the figure will refer to Figure 4 Give a description.

[0072] The process begins with the controller 40 determining the baseline (or initial) impedance Imp of the end effector (blade) of the ultrasonic instrument. 基线 (At box 51). As described herein, the impedance can be a mechanical impedance that can be determined by the controller using one or more of the (monitored) characteristics of the ultrasonic instrument. For example, the controller can determine the input current of the ultrasonic instrument (e.g., for driving the blade of the end effector) and determine the mechanical impedance based on these parameters (e.g., based on Ohm's law). In one aspect, the input voltage can be changed to maintain a current that can be set to compensate for changes in impedance. In one aspect, the controller can determine the impedance by applying one or more of the characteristics to a (predetermined) impedance model of the output mechanical impedance (e.g., an electromechanical model of the impedance of the blade). In another aspect, the controller can determine the impedance of the blade using any known method. In one aspect, the baseline impedance can be at an initial time t 0 The controller may be determined at a specific location, such as when the ultrasonic instrument 20 is coupled to (e.g., inserted into) the generator 25. For example, once the instrument is inserted into the generator, the controller may perform one or more diagnostic operations on the instrument (e.g., to determine one or more characteristics, as described herein) to determine whether the Imp 基线 In another aspect, the generator may be configured to determine Imp 基线 Thus, based on these operations, the generator may determine a baseline impedance of the blade of the end effector and provide that impedance to the controller.

[0073] In some aspects, the baseline impedance may be determined when the end effector is at (or approximately) room temperature (e.g., a temperature between 20° C. and 25° C.) and / or when the end effector is in air (e.g., when the blade of the end effector is not touching an object). In another aspect, the baseline impedance may be determined once and stored in the storage device 44 of the surgical system 1 (or the memory of the controller 40 of the surgical system 1). For example, the baseline impedance may be determined when the instrument is first coupled to the generator. In another aspect, the baseline impedance may be determined each time an ultrasonic instrument is inserted into the generator. In another aspect, the baseline impedance may be determined at startup of the surgical system (e.g., an ultrasonic instrument of the surgical system) (e.g., during initial power-on). In another aspect, the baseline impedance may be a previously determined impedance (e.g., during a previous execution of process 50).

[0074] In one aspect, the baseline impedance Imp 基线 The baseline impedance may be determined as the impedance level of the end effector when the ultrasonic instrument is in a low power state, the end effector is in an open position, and / or the ultrasonic instrument (e.g., the end effector and shaft of the ultrasonic instrument) is not in contact with any object. In another aspect, the baseline impedance may be determined when the ultrasonic instrument enters a cooling period (e.g., each time). In some aspects, Imp 基线 Can be different between different devices. In addition, Imp 基线 It may drift or gradually drop / rise after repeated activation (repeated switching between heating and cooling cycles) throughout a surgical protocol. Since the change in impedance ΔImp (from the baseline impedance level) is what the controller uses to detect whether the end effector is in contact with the object, the controller can be configured to periodically update the baseline impedance value to prevent false object contact detection due to impedance drift or changes due to repeated activation.

[0075] The controller 40 determines the impedance Imp of the end effector (at box 52). For example, the impedance can be a "current" impedance that is determined by the controller during a surgical operation (when the instrument is being used by an operator and is in a cooling cycle). In one aspect, the controller can determine Imp using a similar (or identical) operation as used to determine the baseline impedance. In some aspects, the impedance determined at this time can be determined after the baseline impedance is determined. The controller determines an impedance change ΔImp (at box 53) based on a comparison between the baseline impedance and the determined impedance. Specifically, the impedance change can be the difference between the two impedances, where ΔImp=Imp-Imp 基线 .

[0076] The controller 40 determines the baseline resonant frequency of the end effector (eg, blade) of the ultrasonic instrument (at block 54). For example, the controller may determine t 0 The baseline resonance RF of the knife at基线 , as described with respect to the baseline impedance. In one aspect, the controller may determine Imp 基线 (at least partially) simultaneously (or simultaneously) determine RF 基线 Therefore, RF 基线 Available in 基线 The apparatus may be determined under similar conditions (e.g., determined when the instrument is inserted into a generator, determined at room temperature, etc.).

[0077] In some aspects, the generator electronically determines the resonant frequency. For example, the generator may sense the voltage and current waveforms (and the phase angle difference between the two waveforms) used to drive the blade of the end effector. Specifically, the ultrasonic instrument 20 (e.g., a tool driver) may include an ultrasonic transducer that is configured to vibrate the blade according to the input voltage and current waveforms. The frequency that produces a phase angle difference of a threshold value (e.g., zero) is the resonant frequency. In one aspect, the generator continues to drive the ultrasonic transducer at resonance and may adjust the output voltage (which may be referred to as phase locking) so as to continue to drive at resonance (when the resonant frequency changes with temperature). On the other hand, the controller 40 may adjust the output frequency. On the other hand, other known methods may be used to determine the resonant frequency.

[0078] In one aspect, (at least some) operations performed in box 51 and / or box 54 may be omitted from process 50. For example, as described herein, at least some of these operations may be performed each time the ultrasonic instrument enters a low power state. However, in some aspects, the determination of the baseline impedance and / or baseline frequency may be performed once (e.g., during initial power-on). Thus, process 50 may omit either operation (or both of these operations) in subsequent (at least partial) executions of the process. Thus, boxes 51 and 54 may be optional (e.g., as shown by boxes having dashed borders).

[0079] The controller 40 is configured to determine the (current) resonant frequency RF of the end effector (at block 55). Specifically, the controller may determine RF similarly to the baseline resonant frequency, but may compare the resonant frequency of the end effector to the resonant frequency of the end effector after determining the baseline. 基线RF is determined similarly to Imp. In one aspect, the controller may be configured to determine the impedance (at box 52) and / or the resonant frequency (at box 55) based on the configuration of the ultrasonic instrument. For example, these characteristics may be determined by the surgical system once (or in response to) the end effector of the instrument is in an open position (e.g., while also operating in a low power state). On the other hand, the characteristics may be determined after the controller determines that the end effector is in the open position (either immediately or within a period of time). On the other hand, the controller may determine any of these characteristics once the ultrasonic instrument switches between states, and / or may determine these characteristics periodically after entering a state. The controller determines the resonant frequency change ΔRF (at box 56) based on a comparison between the baseline resonant frequency and the determined resonant frequency. Specifically, the controller may determine the change based on the difference between the frequencies, such that ΔRF=RF-RF 基线 In one aspect, the difference can represent a resonant frequency drift from a baseline (or nominal) resonant frequency to the determined resonant frequency of the blade (or a change therebetween).

[0080] The controller 40 determines whether the impedance change ΔImp is greater than (and / or equal to) the impedance liquid threshold Th Imp(液体) (At decision box 57). In one aspect, at least partial immersion of (the end effector of) the ultrasonic instrument can cause the mechanical impedance Imp to increase (and therefore ΔImp to increase). Specifically, when the ultrasonic instrument is in a low power state, the current entering the instrument is controlled (e.g., set to a predetermined value), and the voltage can change due to immersion in order to maintain the specified current. Therefore, if the end effector is at least partially immersed in the liquid when the mechanical impedance is determined (e.g., at box 52), the change in voltage can cause the determined impedance to increase. In one aspect, Th Imp(液体) This may be a predefined threshold (eg, a threshold determined in a controlled environment).

[0081] If ΔImp <Th Imp(液体) , which means that the end effector (e.g., the blade 30 of the end effector) is not at least partially submerged (e.g., no part of the blade is submerged in the liquid), the controller 40 determines whether the impedance change is greater than the impedance target threshold Th Imp(对象) (At box 63). Specifically, the controller is based on whether ΔImp <Th Imp(对象) To determine whether at least a portion of the end effector during a surgical procedure is in contact (touching) with an object such as tissue, vein, etc. In one aspect, Th Imp(对象) Can be greater than Th Imp(液体) On the other hand, Th Imp(对象) Can be less than Th Imp(液体)If yes, the controller presents a notification indicating that the end effector is in contact with the object (at box 64). For example, the system 1 may display a pop-up notification on the display 15 indicating that the operator (e.g., the ultrasonic instrument being used by the operator) is in contact with the object. As another example, 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 (e.g., beeps) indicating that the end effector is in contact with the object. On the other hand, the notification may be a spoken word (e.g., "The knife is in contact with the object!"). On the other hand, any type of notification may be presented.

[0082] Returning to decision box 57, if ΔImp>Th Imp(液体) , the controller determines whether the resonant frequency change ΔRF is less than (and / or equal to) the resonant frequency threshold TH RF (At decision block 58). Specifically, the controller may determine whether ΔRF <Th RF During the period when the end effector is (at least partially) immersed in the liquid, the impedance of the instrument can increase, while the resonant frequency of the end effector can decrease. In one aspect, the controller can monitor the generator based on the increase in impedance (e.g., ΔImp>Th) during the (same) time period (e.g., the time period during which the generator monitors both characteristics). Imp(液体) ) and the reduction of the resonant frequency (e.g., ΔRF <Th RF ) to determine that the end effector is immersed in the liquid (or in contact with the liquid). Therefore, if these changes occur (e.g., simultaneously or contemporaneously, such as within a period of time), it can be determined that the end effector is in contact with the liquid or has been immersed in the liquid.

[0083] If ΔRF <Th RF , the controller determines the new impedance object threshold Th Imp(对象) '. (at block 59). In one aspect, the new object threshold may be greater than the object threshold of decision block 63, such that Th Imp(对象) '>Th Imp(对象) In one aspect, the controller determines a new threshold value that will be used to determine whether an end effector at least partially submerged in a liquid is also in contact with an object (e.g., in a surgical procedure, an end effector may grasp tissue immersed in saline). The controller may make this determination based on a change in impedance. In one aspect, the controller may increase the impedance object threshold based on a threshold liquid impedance. For example, the controller may increase the threshold value by (at least) the liquid threshold value such that Th Imp(对象) '=Th Imp(对象) +Th Imp(液体) On the other hand, the new threshold impedance can be obtained by changing Th Imp(对象) Increase by a predetermined amount to confirm.

[0084] The controller 40 determines whether the impedance change is greater than the new impedance target threshold Th Imp(对象) ' (at decision box 60). In one aspect, the impedance change is the ΔImp determined at box 53. On the other hand, the controller may determine a new impedance change ΔImp' and use it to make the determination. If the impedance change is less than the new impedance object threshold, the controller 40 presents a notification indicating that the end effector is at least partially immersed in the liquid (at box 62). For example, the controller may display text and / or an image on the display 15 indicating that the end effector is immersed in the liquid, such as an image of raindrops. However, if the impedance change is greater than the new impedance object threshold, the controller 40 presents a notification indicating that the end effector is at least partially immersed in the liquid and (at least partially) in contact with the object (at box 61). For example, the notification can be a pop-up notification with an image of raindrops and text indicating that the end effector is in contact with the object (e.g., text reading "Tissue Contact" is displayed).

[0085] Some aspects may perform one or more variations of the process 50 described herein. For example, specific operations of the process may not be performed in the exact order shown and described. Specific operations may not be performed in a series of continuous operations, and different specific operations may be performed in different aspects. As described herein, the controller may perform at least some of the operations of the process to determine whether the end effector is immersed in a liquid and / or in contact with an object. In some aspects, the controller may determine that the end effector is not immersed in a liquid and / or is not in contact with an object based on the operations performed. For example, in response to a change in resonant frequency greater than Th RF , the controller may determine that the end effector is not (at least partially) immersed in liquid.

[0086] In one aspect, at least some of the operations described herein may be performed simultaneously. For example, the controller may determine whether the impedance change is greater than Th Imp(液体) (at block 57), and simultaneously (at least in part) determining whether the resonant frequency change is less than Th RF In this case, the controller may determine that the end effector is not immersed in the liquid in response to at least one of the characteristics not satisfying the conditions described herein.

[0087] In one aspect, the controller 40 may be configured to determine the type of liquid in which the end effector is at least partially immersed based on one or more of the characteristics of the ultrasonic instrument (e.g., impedance and / or resonant frequency). For example, blood may be more viscous than saline, which may cause the Imp of the end effector to be greater when immersed in blood than when immersed in saline. Therefore, the controller may determine the type of liquid by comparing Imp (and / or ΔImp) to a threshold value. For example, the controller may use an Imp execution table to look up a (predefined) data structure that associates impedance (range) with the type of liquid. The controller may determine the type of liquid having an associated impedance of Imp (similar to or the same as Imp). In one aspect, the notification presented may indicate the type of liquid (e.g., indicating that the end effector is immersed in blood).

[0088] Figure 6 Several stages of a display of a surgical system are shown, the display being displayed showing actions performed by an end effector of an ultrasonic instrument and showing notifications based on whether the end effector is submerged in a liquid and / or in contact with an object. Specifically, each of the three stages 70 to 72 shows the display 15 (and / or the display 24 of the generator 25) showing an endoscopic video 73 showing the end effector 23 and a portion of an object 77 (e.g., tissue, such as a blood vessel) submerged in the liquid 74. In one aspect, the display showing the endoscopic video can be a different display of the surgical system, such as the display 24 of the generator 25. In some aspects, the display can show other content, such as other video content and / or a graphical user interface (GUI) of the surgical system, which is displaying one or more UI items (e.g., UI items related to the surgical procedure being performed by the system operator).

[0089] The first stage 70 shows the end effector 23 in front of the liquid 74 and tissue 77. In one aspect, the end effector can be in air (e.g., in a cavity of a patient during a surgical procedure). In one aspect, the end effector can be in a low power state, where the end effector is hot but in a cooling cycle (e.g., cooling down). In one aspect, at this stage, the controller can determine a baseline impedance and / or a baseline resonant frequency.

[0090] The second stage 71 shows that the end effector 23 (e.g., a portion of the blade 30 of the end effector 23) has entered (moved forward) and is partially immersed in the liquid 74. In this case, the controller may determine that the end effector is in the liquid based on a change in one or more characteristics of the ultrasonic instrument. For example, as described herein, once the blade 30 of the end effector has entered the liquid, the measured impedance of the blade may increase and the measured resonant frequency of the blade may decrease. Therefore, the controller may determine that the blade is immersed in the liquid 74. In addition, this stage shows that in response to the controller determining that the end effector is in the liquid, a notification 75 is displayed on the display 15 (e.g., overlaid on top of the endoscope video 73), which reads "End effector immersed in liquid" to alert the operator to the state of the end effector, which may be outside the operator's field of view.

[0091] The third stage 72 shows that the blade 30 of the end effector 23 has moved further forward (from as shown in the second stage 71) and is now touching the tissue 77 while immersed in the liquid 74. In particular, the controller has made this determination based on additional changes in characteristics (such as the impedance of the end effector). This stage also shows that the display 15 is displaying a notification 76, which indicates that the end effector is immersed in the liquid and is touching the object by including the text "End effector is immersed in liquid and in contact with an object" to alert the operator to the status of the instrument.

[0092] Thus, the diagram shows how the controller can continuously execute Figure 5 At least some of the operations of process 50 shown in FIG. 5 may be performed to (continuously) monitor and update the operator on the status of the instrument.

[0093] As described herein, the surgical system may be configured to determine (estimate) and present (e.g., display on the display 15) the temperature of the end effector (e.g., the blade of the end effector) based on one or more of the monitored characteristics of the ultrasonic instrument (e.g., the resonant frequency) when the instrument is in one of the power states (e.g., the low power state). Specifically, the system 1 (the controller 40) may estimate the temperature based on at least one temperature model that is configured to determine the temperature of the end effector in air. For example, when the instrument is in the low power state, the temperature model may estimate the temperature based on the resonant frequency of the oscillating blade of the end effector. However, if the blade touches an object and / or is immersed in a liquid, the resonant frequency may be adversely affected (e.g., when the blade touches an object, the resonant frequency may increase due to an increase in the stiffness k of the blade as described herein). Therefore, the temperature model may not be able to effectively estimate the temperature of the blade. Therefore, the system may be configured to estimate the temperature of the end effector based on the state of the instrument (e.g., whether the instrument is touching an object and / or immersed in a liquid).

[0094] Figure 7 80 is a flow chart of an aspect of a process 80 for estimating the temperature of an end effector based on detecting that an ultrasonic instrument is at least partially immersed in a liquid. Specifically, the operations may be performed by the controller 40 (and / or the generator 25) of the surgical system 1. The process 80 begins with the controller 40 estimating (and displaying on a display, e.g., Figure 4 The controller may determine the temperature of the end effector of the ultrasonic instrument (displayed on the display 15 of the ultrasonic instrument) (at block 81). Specifically, the controller may determine one or more characteristics of the instrument, such as the resonant frequency of the end effector, and then apply the frequency to a predetermined temperature model that outputs an estimate of the temperature of the end effector. In one aspect, the estimate of the temperature may be performed while the instrument is in air (e.g., not touching an object and / or immersed in a liquid). In some aspects, the temperature estimate may be determined while the instrument is in a cooling cycle (e.g., in a low power state).

[0095] The controller 40 determines one or more characteristics of the end of the ultrasonic instrument (at box 82). Specifically, the controller may determine impedance and / or resonant frequency (e.g., from a generator), as described herein. The controller determines that the end effector is at least partially immersed in a liquid based on the determined one or more characteristics (e.g., at box 83). For example, the controller may determine that the change in impedance ΔImp is greater than an impedance liquid threshold Th in response to determining that the change in impedance ΔImp is greater than an impedance liquid threshold Th Imp(液体) and / or in response to determining that the change in resonant frequency ΔRF is less than a threshold value Th RF To determine whether the end effector blade is immersed in the liquid, such as Figure 5 In response to determining that the end effector is at least partially submerged, the controller displays a notification on a display of the surgical system indicating that the end effector is at least partially submerged in the liquid (at block 84). For example, the system may display a notification such as Figure 6 Notice 75.

[0096] The controller estimates (and displays) a new temperature of the end effector of the ultrasonic instrument based on the end effector being at least partially immersed in the liquid (at box 85). Specifically, the controller may replace the estimated temperature displayed on the display of the system (as described in box 81) with the new temperature estimate. In one aspect, the new temperature estimate may be a temperature associated with the liquid in which the end effector is immersed. Specifically, in the case where the blade is immersed in the liquid, any residual heat of the blade will be quickly dissipated in the liquid. This is due to the high heat capacity of most liquids compared to air. Therefore, the blade will cool (over a period of time) and reach thermal equilibrium with the liquid, where the temperature of the blade will be (approximately) the same as the temperature of the liquid. Therefore, in response to determining that the end effector is at least partially immersed in the liquid, the controller may estimate the temperature of the end effector to be the temperature of the liquid.

[0097] In one aspect, the controller may estimate a new temperature based on a determination of the liquid. For example, as described herein, the controller may be configured to determine the type of liquid in which the end effector is immersed (e.g., based on a change in the resonant frequency of the end effector). In this case, the controller may be configured to determine the new temperature based on a determination of the type of liquid in which the end effector is immersed. For example, the controller may perform a table lookup of a data structure that associates liquid types with temperatures. On the other hand, the controller may determine the temperature of the liquid by other methods. For example, the surgical system may include a temperature sensor that is configured to detect the temperature of the liquid. On the other hand, the temperature of the liquid may be a predefined liquid (e.g., across one or more types of liquids).

[0098] Some aspects may perform variations of the process 80 described herein. For example, specific operations of at least some of the processes may not be performed in the exact order shown and described. Specific operations may not be performed in a series of continuous operations, and different specific operations may be performed in different aspects. For example, the operations within the dashed box may be optional operations that may not be performed when performing the corresponding process. On the other hand, one or more operations (which may or may not have a dashed box) may be optional. In one aspect, at least some of the operations described herein (e.g., at least some of the operations performed in one or more processes described herein) may be performed automatically (e.g., without user intervention). As described herein, the operations of process 80 are used to determine whether the end effector is at least partially immersed, and in response to estimate a new temperature. In some aspects, at least some of these operations may be performed based on whether the end effector is in contact with the object. For example, instead of (or in addition to) determining whether the end effector is immersed, the controller may determine whether the end effector is in contact with the object based on one or more characteristics of the end effector (e.g., impedance) (e.g., at box 83). In response to determining that the end effector is touching the object, the controller can be configured to display a notification and estimate (and display) a new temperature of the end effector based on the end effector touching the object (e.g., in the notification). In this case, the controller can be configured to estimate the temperature of the end effector to be (e.g., approximately) the temperature of the object that the end effector is touching.

[0099] On the other hand, the controller may estimate the temperature of the end effector based on the amount of time the end effector that touches the object is in contact with the object. For example, when the end effector is touching the object, the temperature may change at a predetermined (e.g., linear) rate. In this case, the controller may estimate the temperature based on the predetermined rate and the time the end effector touches the object. In one aspect, the controller may continuously update the displayed new temperature based on how long the end effector touches the object. On the other hand, the controller may determine the temperature based on a temperature (linear) model that linearly adjusts the temperature based on the temperature estimate (before touching the object). In some aspects, the controller may estimate the new temperature of the end effector as the temperature of the liquid when it is determined that the end effector is immersed in the liquid and touches the object. In some aspects, once the knife is immersed in the liquid, regardless of whether the knife is in contact with the object, the temperature of the knife may be estimated as the temperature of the liquid.

[0100] As described herein, the controller may estimate and display the temperature of the end effector. In one aspect, the temperature of the end effector (or an indication of the temperature) may be displayed as a separate notification (or the same notification) from a notification indicating that the end effector is immersed in a liquid (and / or in contact with an object). In another aspect, the notification of the state of the end effector may be based on the temperature. For example, upon determining that the end effector is in contact with an object, the controller may be configured to determine whether the temperature estimate of the end effector (e.g., when in air and before contact with the object) is above a threshold. If so, the displayed notification may alert the operator that the end effector is too hot to touch the object.

[0101] In some aspects, the controller may be configured to estimate the temperature of the end effector using one or more of the stored models described herein in response to determining that the end effector is no longer (at least partially) immersed in a liquid (and / or in contact with an object). For example, the controller may be configured to monitor one or more characteristics of the end effector to determine whether the end effector is no longer immersed. For example, upon determining that the change in impedance is less than an impedance liquid threshold and / or upon determining that the change in resonant frequency is greater than a resonant frequency threshold, the controller may determine that the end effector is no longer immersed (e.g., and is in air). In response, the controller may be configured to estimate and display the temperature of the end effector using one or more of the models described herein, and / or may remove a displayed notification indicating that the end effector is immersed.

[0102] In some aspects, the controller may update Imp (e.g., in real time) by continuously (or over a period of time) monitoring the impedance level Imp (e.g., determining the impedance level one or more times over the period of time). 基线, to prevent false triggering of object contact due to displacement. Specifically, in order to update the baseline impedance, the controller may be configured to determine one or more impedances of the end effector within a time period, and may be configured to determine whether the impedance change across the one or more impedances throughout the time period is less than a threshold. Specifically, the controller may determine whether the one or more impedances remain in a stable state for the time period Δt. If the change in impedance throughout Δt is below the threshold ε, the controller may define Imp based on the change in impedance. 基线 In one aspect, in response to determining that the change is less than a threshold, the controller may use one or more impedances to determine Imp 基线 For example, the controller can 基线 is defined as the average impedance across one or more impedances such that if:

[0103] |Imp(t)-Imp(t+Δt)|<∈

[0104] but,

[0105] Imp 基线 =mean(Imp(t),Imp(t+1),…,Imp(t+Δt))

[0106] In some aspects, the controller may update the baseline impedance when the ultrasonic instrument switches from a heating cycle to a cooling cycle. Specifically, the controller may determine that the ultrasonic instrument is in a heating cycle (e.g., the end effector is in a 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 an open position and / or in air), the controller may (e.g., begin) monitoring the impedance of the end effector over a period of time to determine a new baseline impedance. In some aspects, the new baseline impedance may be different from the previously determined baseline impedance. This may be due to differences in the monitored impedances, which may be due to various factors (e.g., how long the end effector was in the heating cycle before returning to the cooling cycle, etc.).

[0107] As previously described, one aspect of the present disclosure may be a non-transitory machine-readable medium (such as a microelectronic memory) having stored thereon instructions that program one or more data processing components (collectively referred to herein as "processors") to (automatically) perform ultrasonic instrument operations, temperature estimation operations, and / or liquid immersion, and / or object contact detection operations, as described herein. In other aspects, some of these operations may be performed by specific hardware components that include hardwired logic. These operations may alternatively be performed by any combination of programmed data processing components and fixed hardwired circuit components.

[0108] Although certain aspects have been described and shown in the accompanying drawings, it should be understood that such aspects are merely illustrative of the present disclosure and not limiting, and the present disclosure is not limited to the specific constructions and arrangements shown and described, as various other modifications may occur to those skilled in the art. Therefore, this description should be regarded as illustrative rather than limiting.

[0109] In some aspects, the present disclosure may include language such as, “at least one of [element A] and [element B]”. The language may refer to one or more of the elements. For example, “at least one of A and B” may refer to “A”, “B”, or “A and B”. Specifically, “at least one of A and B” may refer to “at least one of A and at least one of B” or “at least one of A or B”. In some aspects, the present disclosure may include language such as, “[element A], [element B], and / or [element C]”. The language may refer to any one of these 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”.

Claims

1. A method performed by a surgical system, the method comprising: determining one or more characteristics of an end effector of an ultrasonic instrument; determining that the end effector is at least partially submerged within the liquid based on the determined one or more characteristics; as well as In response, a notification is displayed on a display of the surgical system indicating that the end effector is at least partially submerged in the liquid.

2. The method of claim 1, wherein the one or more characteristics include an impedance of the end effector, wherein determining that the end effector is at least partially submerged includes determining that the impedance is above an impedance threshold.

3. The method of claim 2, wherein the one or more characteristics include a resonant frequency of the end effector, wherein determining that the end effector is at least partially submerged further comprises determining that the resonant frequency is below a resonant frequency threshold.

4. The method of claim 1, further comprising determining a type of liquid in which the end effector is at least partially immersed based on the one or more characteristics, wherein the notification indicates the type of liquid.

5. The method of claim 1 , wherein the one or more characteristics include an impedance of the end effector, wherein determining that the end effector is at least partially submerged includes determining that the impedance is above a first threshold, wherein the method further comprises determining that the end effector is in contact with an object while at least partially submerged within the liquid in response to the impedance being above a second threshold that is greater than the first threshold.

6. The method of claim 5, wherein the notification indicates that the end effector is in contact with an object while submerged in a liquid.

7. The method according to claim 1, further comprising: When the end effector is in the air, determining a temperature of the end effector, and displaying the temperature on the display; as well as In response to determining that the end effector is at least partially submerged, the temperature is replaced with an estimated temperature of the liquid.

8. A surgical system comprising: An ultrasonic instrument having an end effector: monitor; processor; and a memory having instructions that, when executed by the processor, cause the surgical system to determining one or more characteristics of the end effector of the ultrasonic instrument, determining that the end effector is at least partially submerged within the liquid based on the determined one or more characteristics, and In response, a notification is displayed on the display indicating that the end effector is at least partially submerged in the liquid.

9. The surgical system of claim 8, wherein the one or more characteristics include an impedance of the end effector, wherein the instructions for determining that the end effector is at least partially submerged include instructions for determining that the impedance is above an impedance threshold.

10. The surgical system of claim 9, wherein the one or more characteristics include a resonant frequency of the end effector, wherein the instructions for determining that the end effector is at least partially submerged further comprise instructions for determining that the resonant frequency is below a resonant frequency threshold.

11. The surgical system of claim 8, wherein the memory has additional instructions for determining a type of liquid in which the end effector is at least partially immersed based on the one or more characteristics, wherein the notification indicates the type of liquid.

12. The surgical system of claim 8, wherein the one or more characteristics include an impedance of the end effector, wherein the instructions for determining that the end effector is at least partially submerged include instructions for determining that the impedance is above a first threshold, wherein the memory has additional instructions for determining that the end effector is in contact with an object while at least partially submerged within the liquid in response to the impedance being above a second threshold that is greater than the first threshold.

13. The surgical system of claim 12, wherein the notification indicates that the end effector is in contact with an object while submerged in a liquid.

14. The surgical system of claim 8, wherein the memory has additional instructions for: When the end effector is in the air, determining a temperature of the end effector, and displaying the temperature on the display; and replacing the temperature with an estimated temperature of the liquid in response to determining that the end effector is at least partially submerged.

15. A non-transitory machine-readable medium having instructions which, when executed by a processor of a surgical system, cause the surgical system to: determining one or more characteristics of an end effector of an ultrasonic instrument, determining that the end effector is at least partially submerged within the liquid based on the determined one or more characteristics, and In response, a notification is displayed on a display of the surgical system indicating that the end effector is at least partially submerged in the liquid.

16. The non-transitory machine-readable medium of claim 15, wherein the one or more characteristics include an impedance of the end effector, wherein the instructions for determining that the end effector is at least partially submerged include instructions for determining that the impedance is above an impedance threshold.

17. The non-transitory machine-readable medium of claim 16, wherein the one or more characteristics include a resonant frequency of the end effector, wherein the instructions for determining that the end effector is at least partially submerged further comprise instructions for determining that the resonant frequency is below a resonant frequency threshold.

18. A non-transitory machine-readable medium according to claim 15, wherein the non-transitory machine-readable medium has additional instructions for determining a type of liquid in which the end actuator is at least partially immersed based on the one or more characteristics, wherein the notification indicates the type of liquid.

19. A non-transitory machine-readable medium according to claim 15, wherein the one or more characteristics include an impedance of the end effector, wherein the instructions for determining that the end effector is at least partially immersed include instructions for determining that the impedance is above a first threshold, wherein the non-transitory machine-readable medium has additional instructions for determining that the end effector is in contact with an object while at least partially immersed in the liquid in response to the impedance being above a second threshold that is greater than the first threshold.

20. The non-transitory machine-readable medium of claim 19, wherein the notification indicates that the end effector is in contact with an object while submerged in a liquid.

21. The non-transitory machine-readable medium of claim 15 having further instructions for: When the end effector is in the air, determining a temperature of the end effector, and displaying the temperature on the display; and replacing the temperature with an estimated temperature of the liquid in response to determining that the end effector is at least partially submerged.

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