Patent Description:
Systems and methods that detect or differentiate tissue(s) or artifacts, such as vessels, in the surgical field during a surgical procedure provide valuable information to the surgeon or surgical team. hospitals lose billions of dollars annually in unreimbursable costs because of inadvertent vascular damage during surgery. In addition, the involved patients face a mortality rate of up to <NUM>%, and likely will require corrective procedures and remain in the hospital for up to an additional nine days, resulting in tens, if not hundreds, of thousands of dollars in added costs of care. Consequently, there is significant value to be obtained from methods and systems that permit accurate detection or differentiation of tissue(s) or artifacts, such as vessels, in the surgical field, such that these costs may be reduced or avoided.

Systems and methods that provide such information are particularly important during minimally invasive surgical procedures. Traditionally, surgeons have relied upon tactile sensation during surgical procedures both to identify blood vessels, for example, and to avoid inadvertent damage to these vessels. Because of the shift towards minimally invasive procedures, including laparoscopic and robotic surgeries, surgeons have lost the ability to use direct visualization and the sense of touch to make determinations as to the presence of tissue(s) or artifacts in the surgical field, and to differentiate between those tissue(s) or artifacts. Consequently, surgeons must make the determination whether certain tissues or artifacts are present in the surgical field based primarily on convention and experience. Unfortunately, anatomical irregularities frequently occur because of congenital anomalies, scarring from prior surgeries, and body habitus (e.g., obesity). Systems and methods that would permit surgeons to determine the presence and/or the characteristics of tissue(s) and artifacts in the surgical field during surgery (potentially in real time or near real time) under such conditions would provide a significant advantage.

On the other hand, while it would be advantageous to include systems and methods that provide such information about the surgical field, the adoption of these systems and methods would be impeded if the systems and methods made the surgical procedure more complicated. Consequently, it is advantageous that the systems and methods do not involve significant thought on the part of the surgeon or surgical team in using the system or method for detecting or differentiating tissue or an artifact, like a vessel, or significant preparation of the surgical field or the patient for use of the system or method.

As set forth in more detail below, the present disclosure describes a systems and methods embodying advantageous alternatives to the existing systems and methods, which may provide for improved detection and/or differentiation for avoidance or isolation of tissue or artifacts, such as vessels, without undue complication of the surgical instrument or surgical procedure.

The invention is defined by the appended claims and relates to a surgical system. Methods are useful to understand the claimed invention. According to an aspect of the present disclosure, a surgical system includes a stimulation generator, at least one sensor, and a controller coupled to the at least one sensor. The controller is configured to determine if a tissue or an artifact proximate to the at least one sensor has undergone a change in response to a stimulation applied by the stimulation generator, and to indicate if the tissue or artifact is present within a region proximate to a working end of a surgical instrument based on the presence or absence of the change in response to a stimulation applied by the stimulation generator.

According to another aspect of the present disclosure, a method for operating a surgical system to determine whether tissue or an artifact is in the surgical field is provided. The method includes obtaining a first set of sensor data from at least one sensor, applying a stimulation to the surgical field after obtaining the first set of sensor data, obtaining a second set of sensor data from the at least one sensor after applying the stimulation to the surgical field, and comparing the first set of sensor data with the second set of sensor data to determine whether tissue or an artifact is in the surgical field.

According to an aspect of the present disclosure, a surgical system includes a stimulation generator, at least one sensor disposed at a working end of a surgical instrument, and a controller coupled to the at least one sensor. The controller is configured to obtain data from the at least one sensor over time in response to a stimulation applied by the stimulation generator, analyze the data obtained from the at least one sensor over time to generate sensor data analysis results, apply a signal processing method and/or a pattern matching to the sensor data analysis results, and indicate if a tissue or artifact is present within a region proximate to the working end of the surgical instrument based on the signal processing method or pattern matching.

According to another aspect of the present disclosure, a method is provided for operating a surgical system to determine whether tissue or an artifact is in the surgical field. The method includes applying a stimulation to the surgical field, obtaining data from at least one sensor over time, the at least one sensor disposed at a working end of a surgical instrument, analyzing the data obtained from the at least one sensor over time to generate sensor data analysis results, applying a signal processing method and/or a pattern matching to the sensor data analysis results, and indicating if the tissue or artifact is present within a region proximate to a working end of a surgical instrument based on the signal processing method or pattern matching.

The disclosure will be more fully understood from the following description taken in conjunction with the accompanying drawings. Some of the figures may have been simplified by the omission of selected elements for the purpose of more clearly showing other elements. Such omissions of elements in some figures are not necessarily indicative of the presence or absence of particular elements in any of the exemplary embodiments, except as may be explicitly delineated in the corresponding written description. None of the drawings is necessarily to scale.

The embodiments described herein provide systems and methods for detecting or differentiating tissues and/or artifacts, such as vessels. Such a system may include or a method may use a stimulation generator and at least one sensor, the at least one sensor coupled to a controller that is configured to determine if a tissue or an artifact proximate to the at least one sensor has undergone a change in response to a stimulation applied by the stimulation generator, and to indicate if the tissue or artifact is present within a region proximate to a working end of a surgical instrument based on the presence or absence of the change in response to a stimulation applied by the stimulation generator.

In the context of the claimed invention, the stimulation generator is an electrical stimulation generator. Further, the electrical stimulation generator may apply an electrical field or current to the tissue or artifact, which field or current may be varied to change the characteristics of the response of the tissue or artifact. The electrical stimulation generator may include or be electronically connected or coupled to, for example, one or more surface electrodes, one or more inserted electrodes, or one or more intraoperative probes or needles. Alternatively, in further configurations useful to understand the claimed invention, the stimulation generator may apply pressure or heat to the tissue or artifact to obtain a change in the tissue or artifact. In embodiments useful for detecting and differentiating a ureter, the stimulation generator is an electrical stimulation generator.

For some embodiments, and in the context of the claimed invention, the at least one sensor includes at least one light emitter (or simply the light emitter) and at least one light sensor or detector (or simply the light sensor). The light emitter and the light sensor may be disposed at the working end of the surgical instrument. The light emitter and light sensor may operate according to a transmittance-based approach, such that the light sensor is disposed opposite and facing the light emitter, for example on opposite jaws of a surgical instrument. The light emitter and light sensor may instead operate according to a reflectance-based approach, such that the light emitter and the light sensor may face in a common direction and with fixed or variable spacing therebetween.

For other embodiments, embodiments useful to understand the claimed invention, the at least one sensor may include a measurement of the impedance between electrodes of the stimulation generator before and after stimulation. Further embodiments for the at least one sensor may include measurements of the change in the electrical potential of the tissue or changes in the resistance between the electrodes of the stimulation generator before and after stimulation.

Turning first then to <FIG>, an embodiment of a surgical system <NUM> is illustrated, which system <NUM> may be used to determine, for example, a characteristic (e.g., presence, diameter, etc.) of a vessel, V, within a region <NUM> of tissue, T, proximate to a working end <NUM> of a surgical instrument <NUM>. It will be understood that the vessel V may be connected to other vessels with the region <NUM> of tissue T, and in addition, the vessel V may extend beyond the region <NUM> so as to be in fluid communication with other organs (e.g., the heart) also found in the body of the patient. Furthermore, while the tissue T appears in <FIG> to surround fully the vessel V (in terms of both circumference and length) to a particular depth, this need not be the case in all instances where the system <NUM> is used. For example, the tissue T may only partially surround the circumference of and/or only surround a section of the length of the vessel V, or the tissue T may overlie the vessel V in a very thin layer. As further non-limiting examples, the vessel V may be a ureter, and the tissue T may be connective tissue, adipose tissue and/or liver tissue.

According to the illustrated embodiments, the working end <NUM> of the surgical instrument <NUM> is also a distal end of a shaft <NUM>. Consequently, the working end and the distal end will be referred to as working end <NUM> or distal end <NUM>. The shaft <NUM> also has a proximal end <NUM>, and a grip or handle <NUM> (referred to herein interchangeably as grip <NUM>) is disposed at the proximal end <NUM> of the shaft <NUM>. The grip <NUM> is designed in accordance with the nature of the instrument <NUM>; as to the thermal ligation device illustrated in <FIG>, the grip <NUM> may be a pistol-type grip including a trigger <NUM>. As one alternative, finger rings arranged in a generally scissors-type grip may be used.

While the working or distal end <NUM> and the proximal end <NUM> with grip <NUM> are illustrated as disposed at opposite-most ends of the shaft <NUM>, it will be recognized that certain surgical instruments have working ends (where a tool tip is attached, for example) disposed on the opposite-most ends of the shaft and a gripping region disposed intermediate to the opposite working ends. In accordance with the terms "distal" and "proximal" as used herein, the working ends of such an instrument are referred to herein as the distal ends and the gripping region as the proximal end. Relative to the illustrated embodiments, however, the distal and proximal ends are located at opposite-most (or simply opposite) ends of the shaft <NUM>.

As mentioned above, a stimulation generator <NUM> is provided, which stimulation generator <NUM> may be connected or coupled to one or more electrodes <NUM>, which electrodes <NUM> may be disposed at the working end <NUM> of the surgical instrument <NUM>. As illustrated, there are two electrodes <NUM> provided at the working end <NUM> of the surgical instrument <NUM>. These electrodes <NUM> may be coupled to the stimulation generator <NUM> via one or more wires or leads that travel along the shaft <NUM> of the surgical instrument <NUM>. While the stimulation generator <NUM> is illustrated as separate from the surgical instrument <NUM> in <FIG>, according to other embodiments, the stimulation generator <NUM> may be disposed on or in the surgical instrument <NUM>.

In operation, the stimulation generator <NUM> provides an electrical current, for example a pulsed electrical current, to the working end <NUM> of the surgical instrument <NUM>, and in particular the electrodes <NUM>. When the electrodes <NUM> are disposed on or near certain muscle tissue, for example, the application of the electrical current, in particular pulsed electrical current, causes the muscle tissue to respond (e.g., contract). Specifically, it is known that when a patient is under general anesthetic for intra-abdominal operation, the skeletal muscle tissue of the patient will not respond to electrical stimulation, while the smooth muscle will respond. As such, an electrical stimulation applied to an artifact, such as a ureter, will cause the ureteral muscles to contract up and down the length of the ureter, resulting in movement of the ureter, which movement may be sensed even if other tissue (e.g., connective or adipose tissue) limits or prevents direct visualization of the ureter.

While such movement may be detectable through direct visualization or by remote visualization (e.g., on a video monitor such as commonly used in laparoscopic or robotic procedures), visualization of any particular point within the surgical field can be challenging at the best of times. Tissues and fluids can obscure the field, such that movement may be challenging to detect simply by looking for visual cues. Consequently, enhanced and/or automated sensing techniques can be of assistance when using stimulation of the ureter to aid in its detection and/or differentiation.

According to the claimed invention and as illustrated in <FIG>, the surgical system <NUM> includes at least one sensor having at least one light emitter <NUM> (or simply the light emitter <NUM>) and at least one light sensor or detector <NUM> (or simply the light sensor <NUM>). See <FIG>, <FIG>. As illustrated, the light emitter <NUM> is disposed at the working end <NUM> of the surgical instrument <NUM>, and the light sensor <NUM> is also disposed at the working end <NUM> of the surgical instrument <NUM>. A controller <NUM> is coupled to the light emitter <NUM> and the light sensor <NUM>, which controller <NUM> may include a splitter <NUM> and an analyzer <NUM> as explained below.

The at least one sensor may operate according to a transmittance-based approach, such that the light sensor(s) <NUM> is/are disposed opposite and facing the light emitter(s) <NUM>, for example on opposite jaws <NUM>, <NUM> of a surgical instrument <NUM> as illustrated in <FIG>. In addition or the alternative, the system <NUM> may include a reflectance-based system (for forward-facing vessel and/or tissue detection), such that the light emitter <NUM> and the light sensor <NUM> may face in a common direction (at the tip, as illustrated, or to the side of the jaws <NUM>, <NUM>, for example) and with fixed spacing therebetween, for example on a single jaw <NUM> of a two-jaw device (see <FIG>). The light emitter <NUM> and the light sensor <NUM> of a reflectance-based system instead may be constructed such that the spacing between the light emitter <NUM> and the light sensor <NUM> may be adjusted, for example by positioning the light emitter <NUM> at the end or tip (or side) of one of the jaws <NUM> of a two-jaw device and the light sensor <NUM> at the end or tip (or side) of the other the jaws <NUM> of the two-jaw device (see <FIG>). As to the operation of such reflectance-based systems, see <CIT>.

It will be recognized that while embodiments have been illustrated wherein the surgical instrument <NUM> has jaws <NUM>, <NUM>, the system could be used with surgical instruments or tools that do not have jaws, or that are blunt-tipped. It will be further recognized that the electrode and sensor placement may be similar to the embodiments wherein the sensor is placed on a single jaw, e.g., on the end of the blunt-tipped instrument or tool or to the side of the blunt-tipped instrument or tool.

The light emitter <NUM> may be configured to emit light of at least one wavelength. For example, the light emitter <NUM> may emit light having a wavelength of <NUM>. This may be achieved with a single element, or a plurality of elements (which elements may be arranged or configured into an array, for example, as explained in detail below). In a similar fashion, the light sensor <NUM> is configured to detect light at the at least one wavelength (e.g., <NUM>). According to the embodiments described herein, the light sensor <NUM> includes a plurality of elements, which elements are arranged or configured into an array.

According to certain embodiments, the light emitter <NUM> may be configured to emit light of at least two different wavelengths, and the light sensor <NUM> may be configured to detect light at the at least two different wavelengths. As one example, the light emitter <NUM> may emit and the light sensor <NUM> may detect light in the visible range and light in the near-infrared or infrared range. Specifically, the light emitter <NUM> may emit and the light sensor <NUM> may detect light at <NUM> and at <NUM>. Such an embodiment may be used, for example, to ensure optimal penetration of blood vessel V and the surrounding tissue T under in vivo conditions.

Light of additional wavelengths may also be emitted and sensed. For example, if the method of detection is found to be sensitive to varying rates of blood flow in the vessel of interest, light at <NUM> (i.e., at the isobestic point) may be emitted and sensed to permit normalization of the results to limit or eliminate the effects of changes in blood flow rate.

According to some embodiments, the individual light sensor <NUM> is configured to generate a signal comprising a first pulsatile component and a second non-pulsatile component. It will be recognized that the first pulsatile component may be an alternating current (AC) component of the signal, while the second non-pulsatile component may be a direct current (DC) component. Where the light sensor <NUM> is in the form of an array, the pulsatile and non-pulsatile information may be generated for each element of the array, or at least for each element of the array that defines the at least one row of the array.

As to the pulsatile component, it will be recognized that a blood vessel may be described as having a characteristic pulsation of approximately <NUM> pulses (or beats) per minute. While this may vary with the patient's age and condition, the range of pulsation is typically between <NUM> and <NUM> pulses (or beats) per minute. The light sensor <NUM> will produce a signal (that is passed to the controller <NUM>) with a particular AC waveform that corresponds to the movement of the blood through the vessel. In particular, the AC waveform corresponds to the light absorbed or reflected by the pulsatile blood flow within the vessel. On the other hand, the DC component corresponds principally to light absorbed, reflected and/or scattered by the superficial tissues.

The controller <NUM> is coupled to the light sensor <NUM>, and includes a splitter <NUM> to separate the first pulsatile component from the second non-pulsatile component from a signal from the at least one light sensor. The splitter <NUM> may separate the first pulsatile component from the second non-pulsatile component for each element of the light sensor array <NUM>. The controller <NUM> also includes an analyzer <NUM> to analyze the pulsatile and/or non-pulsatile component. The analyzer <NUM> may analyze the pulsatile and/or non-pulsatile component to determine the presence of and/or characteristic(s) of the vessel V within the region <NUM> proximate to the working end <NUM> of the surgical instrument <NUM> based (at least in part) on the pulsatile component.

<FIG> illustrates a method <NUM> for operating the system <NUM> to make a determination whether tissue or an artifact, for example a ureter, is in the surgical field. According to the illustrated embodiment, where the stimulation generator <NUM> is controlled by the controller <NUM>, the method <NUM> may be carried out by the controller <NUM>, the controller <NUM> coordinating the operation of the stimulation generator <NUM> and the at least one sensor. As such, as to those embodiments where the controller <NUM> includes a processor and memory, the method <NUM> may be stored as a set of instructions in the memory, which set of instructions when executed by the processor causes the steps of the method <NUM> to be performed.

The method <NUM> begins at block <NUM>, where the controller <NUM> waits for a start signal. According to the illustrated embodiment, the start signal is used to coordinate the stimulation generator <NUM> and the sensor. Such coordination is necessary according to the illustrated embodiment because the determination as to whether a ureter is present or not is dependent upon a comparison of sensor data before and after the application of stimulation to the tissue (e.g., ureter). Consequently, coordination of the stimulation generator <NUM> and the sensor in a chronological sense is part of the illustrated method <NUM>, although it need not be required by every method of operation of the system <NUM>. If no start signal is received, the method <NUM> remains at block <NUM>.

Once a determination is made at block <NUM> that the start signal has been received, the controller <NUM> obtains sensor data (e.g., a first set of sensor data) from the at least one sensor, for example from the light sensor(s) <NUM> associated with the light emitter <NUM>, at block <NUM>. According to some embodiments, the at least one sensor may be operational at all times during the method <NUM>. According to other embodiments, the at least one sensor may be operational only during the time periods before and after the operation of the stimulation generator <NUM> and the application of the stimulation to the tissue or artifact. In addition, it will be recognized that the activity of block <NUM> may include the controller <NUM> obtaining sensor data from more than one sensor; for example, the controller <NUM> may obtain sensor data from the light-based sensor including the light emitters <NUM> and light sensor <NUM> and from an impedance-based sensor. The controller <NUM> may obtain the sensor data from these sensors at the same time, or may obtain data from one of the sensors and then the other.

After the controller <NUM> has obtained the sensor data at block <NUM>, the controller <NUM> operates the stimulation generator <NUM> to apply a stimulation to the tissue-of-interest, e.g., the ureter. The controller <NUM> may do this by opening and closing a switch, for example, to apply an electrical current across the electrodes <NUM>. The amount of time that elapses between the activity at block <NUM> and the activity at block <NUM> may be selected to limit the likelihood that the sensor data will be influenced by the operation of the stimulation generator <NUM>. After the controller <NUM> has operated the stimulation generator <NUM> to apply the stimulation at block <NUM>, the method <NUM> continues to block <NUM>.

At block <NUM>, the controller <NUM> obtains sensor data (e.g., a second set of sensor data) from the at least one sensor after the stimulation has been applied. The comments made relative to the controller <NUM> obtaining the sensor data at block <NUM> apply equally to the activity at block <NUM>. The amount of time that elapses between the activity at block <NUM> and the activity at block <NUM> again may be selected to limit the likelihood that the sensor data will be influenced by the operation of the stimulation generator <NUM>.

At block <NUM>, the sensor data obtained before the application of the stimulation to the tissue is compared with the sensor data obtained after the application of the stimulation to the tissue. Based on the comparison, a determination is made at block <NUM> whether a ureter is present within the surgical field. If a determination is made that a ureter is present, then the method continues to block <NUM>, and the controller activates an associated output device, such as is referenced below, to provide an indication (e.g., visual, audible, or tactile) to the operator (e.g., surgeon) to alert the operator to the presence of the ureter in the surgical field. If the determination is made that the ureter is not present, then the method returns to block <NUM>, where the controller again waits for a start signal to repeat the steps of the method <NUM>.

The sensor data that is obtained and compared in the method <NUM> may vary according to the sensor included in the system <NUM>. Similarly, while reference has been made herein to other applications describing systems and methods of operation for light-based sensors, which systems and methods may permit a determination to be made as to the presence and characteristics (e.g., diameter) of tissues and/or artifacts, it is not necessary that the sensors be operated according to the entirety of the methods described therein to be useful herein. For example, while the light-based sensor (emitters <NUM>/sensor <NUM>) may provide sensor data that may permit the controller <NUM> to determine the size and location of a vessel in the surgical field for the period before and after the stimulation is applied, it is not necessary that the controller <NUM> operate to determine the size and location of the vessel to make the determination that a ureter is present. Variation of the sensor data, or in specific parts of the sensor data, may permit a meaningful comparison and determination to be made, even if the size and location of the ureter is not determined. According to other embodiments, the presence, size and location of the ureter may be determined as part of the method <NUM>.

As to light-based sensors, <FIG> illustrates a method <NUM> that may be included as part of or integrated into the method <NUM> illustrated in <FIG>, or may be used in the alternative to the method <NUM> of <FIG>. The method <NUM> may begin at block <NUM>, where the method <NUM> determines if an input has been received to start the analysis. For example, the input to the method <NUM> may be the operation of the stimulation generator <NUM>, or may be a signal that is received by the stimulation generator <NUM> to initiate the stimulation. Until the input (or trigger) is received, the method <NUM> may loop at block <NUM>.

Once the input is received at block <NUM>, the method <NUM> continues at block <NUM>, where sensor data is obtained or collected over time. For example, the data from the sensors <NUM> may be obtained over a period of time, such as several seconds. Thus, according to certain embodiments, the sensor data may be obtained for five seconds, while according to other embodiments, the sensor data may be obtained for three seconds. Further alternatives are also possible. According some embodiments, the beginning of the time period may extend before the stimulation generator is operated, and thus the data obtained may include at least one set before the stimulation generator is operated and at least one set after the stimulation generator is operated. According other embodiments, the time period may extend from shortly after the stimulation generator is operated to some point later in time.

It is presently believed that collecting the sensor data over time will permit the detection of the ureter and the separation of the response of the ureter from the response of other tissues proximate to the ureter. Some of these tissues will have a very weak response to the stimulation, remaining almost static. Other tissues, such as the bowel, which has smooth muscle tissue like the ureter, may exhibit a response over time that is different from that of the ureter, and so it is presently believed that the difference in response may be used to separate the ureter from the bowel, for example.

Once the sensor data has been obtained at block <NUM>, the sensor data is analyzed at block <NUM>. According to certain embodiments, the derivative of the time response of the sensor data may be used to analyze the data. As one such example, where a two-dimensional sensor array of light sensor (e.g., a camera) is used, a frame-by-frame comparison may be used to identify the changes over time, and then time derivative plots used for analysis. According to other embodiments, time-frequency analysis methods may be used, such as wavelet, short-time Fourier transform (STFT), and Wigner-Ville analysis methods. For a time-frequency analysis, it is presently believed that a high sampling rate (e.g., on the order of <NUM>) may provide suitable results, but other sampling rates may be used instead. According to further embodiments, the time-based analysis methods may be used in conjunction with time-frequency analysis methods.

In any event, once the analysis has been performed on the sensor data, the method <NUM> continues to block <NUM> or block <NUM>. As illustrated in <FIG>, either one of the actions of block <NUM> or block <NUM> may follow the analysis of block <NUM>. Consequently, the method <NUM> may proceed from block <NUM> to block <NUM>, or from block <NUM> to block <NUM>. An embodiment may even include both the actions of block <NUM> and of block <NUM>, the results of block <NUM> being used as a confirmation of the results of block <NUM>, or vice versa.

At block <NUM>, a signal processing method may be applied to the results of the sensor data analysis occurring at block <NUM>. For example, the result of the analysis at block <NUM> may be compared against a threshold to determine if a ureter is present or not. Alternatively, mean squared error (MSE) processing may be performed on a tensor (matrix) including the time data for each sensor along the sensor array, with a two-dimensional tensor being used for a row of sensors (i.e. a one-dimensional array) and a three-dimensional tensor being used for a two-dimensional array of sensors. According to the latter case, a three-dimensional tensor may be limited to embodiments where the two-dimensional sensor array is not more than a few sensors (or pixels) in one of the two dimensions of the sensor array.

At block <NUM>, pattern matching may be applied to the results of sensor data analysis occurring at block <NUM>. This pattern matching may be combined with machine learning, such that the controller <NUM>/analyzer <NUM> may learn to recognize the patterns of sensor data associated with a ureter, as opposed to a bowel, for example.

In either event, the method <NUM> continues to block <NUM> after blocks <NUM>, <NUM>. At block <NUM>, an output may be provided, which output may be associated with the presence of a ureter or with the absence of a ureter. This output may be used in the method <NUM>, for example at block <NUM>, to make the determination as to the presence of the ureter, which determination may then lead to the activation of an output device at block <NUM>. According to certain embodiments, the actions of blocks <NUM>, <NUM> of method <NUM> may included in the action of block <NUM>, such that the output provided at block <NUM> is a signal to activate an output device if a ureter is present.

Having discussed the system <NUM> in general terms and method <NUM>, the details of the system <NUM> are now discussed, starting with the stimulation generator <NUM>.

As mentioned above, the stimulation generator <NUM> may be separate from the surgical instrument <NUM>, or may be integrated into the surgical instrument <NUM>. For example, the stimulation generator <NUM> may be disposed and housed in the same physical housing as the remainder of the controller <NUM>, such as the splitter <NUM> and analyzer <NUM>. As such, the stimulation generator <NUM> may be connected to the electrodes <NUM> via wires or leads along the shaft <NUM>. Placement of the generator <NUM> in the housing of the surgical instrument <NUM> would limit or eliminate the need for such wires or leads. Alternative, the stimulation generator <NUM> may be wholly separate from the surgical instrument <NUM> and controller <NUM>, such that the generator <NUM> may be housed instead in an instrument or tool that is used along side the surgical instrument <NUM>, for example. According to the illustrated embodiment, the generator <NUM> is housed with the controller <NUM>, and may be controlled by the controller <NUM> as explained in greater detail below, which placement with the controller <NUM> may also permit the generator <NUM> to be placed remotely such that, like the controller <NUM>, the generator <NUM> may be reused and may not need to be sterilized to the same extent as the remainder of the system <NUM> (e.g., the surgical instrument <NUM>).

<FIG> illustrates an embodiment of an electrical stimulation generator <NUM>. The generator <NUM> is operated to provide a pulsed electrical current across the electrodes <NUM>. The generator <NUM> may be configured to provide, for example, a pulsed electrical current with the following characteristics: a pulse width of <NUM> to <NUM>, a frequency of <NUM> to <NUM>, a pulse amplitude of <NUM> mV to 500V, and a pulse intensity of <NUM> to <NUM> mA. Such a pulsed electrical current is believed to be particularly suited to stimulate the smooth muscle of the ureter.

The electrical stimulation generator <NUM> includes a switch or a transistor <NUM>, which switch or transistor <NUM> may be coupled to a controller; in the illustrated embodiment, the switch/transistor <NUM> is coupled to the controller <NUM>. The switch <NUM> is connected between a resistor <NUM> and a capacitor <NUM>, which capacitor may have a fixed value capacitance. The junction of the switch <NUM> and the capacitor <NUM> is connected to first and second resistors <NUM>, <NUM>, which are respectively connected to a first transformer <NUM> and a second transformer <NUM>. The transformers <NUM>, <NUM> may be step-up transformers with a fixed ratio.

The controller <NUM> operates the switch/transistor <NUM> to open and close to provide the desired frequency and pulse width. The resistors <NUM>, <NUM>, <NUM> may be selected to provide the desired pulse amplitude and current intensity. In fact, the resistors <NUM>, <NUM>, <NUM> may be in the form of potentiometers, to permit the pulse amplitude and current intensity to be changed or varied.

Turning next to the at least one sensor, It will be recognized that a light-based sensor using transmittance or reflectance was described above in general terms above. The transmittance-based approach will now be described in greater detail with reference to <FIG>.

A transmittance-based embodiment is illustrated in <FIG>, wherein the light emitter <NUM> may include one or more elements, as referenced above. According to an embodiment schematically illustrated in <FIG>, the light sensor <NUM> may include a first light emitter <NUM>-<NUM>, a second light emitter <NUM>-<NUM>, and a third light emitter <NUM>-<NUM>. All of the light emitters may be configured to emit light at a particular wavelength (e.g., <NUM>), or certain emitters may emit light at different wavelengths than other emitters. Each light emitter may be a light emitting diode, for example.

As to those embodiments wherein the light emitter <NUM> is in the form of an array including one or more light emitting diodes, as is illustrated in <FIG>, the diodes may be arranged in the form of a one-dimensional, two-dimensional or three-dimensional array. An example of a one-dimensional array may include disposing the diodes along a line in a single plane, while an example of a two-dimensional array may include disposing the diodes in a plurality of rows and columns in a single plane. Further example of a two-dimensional array may include disposing the diodes along a line on or in a curved surface. A three-dimensional array may include diodes disposed in more than one plane, such as in a plurality of rows and columns on or in a curved surface.

The light sensor <NUM> also may include one or more elements. Again, according to the embodiment illustrated in <FIG>, the light sensor <NUM> may include a first light sensor <NUM>-<NUM>, a second light sensor <NUM>-<NUM>, an n-th light sensor <NUM>-n, and so on. As was the case with the light emitters <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, the light sensors <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-n may be arranged in an array, and the discussion about the arrays above applied with equal force here.

In fact, where the array of light sensors <NUM> includes a row of light sensors (such as in <FIG>), the array <NUM> may be referred to in the alternative as a linear array. The individual light sensors of the array <NUM> may be disposed adjacent each other, or the light sensors may be spaced from each other. It may even be possible for the individual light sensors that define a row of light sensors to be separated from each other by light sensors that define a different row or column of the array. According to a particular embodiment, however, the array may comprise a charge coupled device (CCD), and in particular linear CCD imaging device comprising a plurality of pixels. As a further alternative, a CMOS sensor array may be used.

While the emitter <NUM> and the sensor <NUM> are described as disposed at the working end <NUM> of the surgical instrument <NUM>, it will be recognized that not all of the components that define the emitter <NUM> and the sensor <NUM> need be disposed at the working end of the instrument <NUM>. That is, the emitter <NUM> may comprise a light emitting diode, and that component may be disposed at the working end <NUM>. Alternatively, the emitter <NUM> may include a length of optical fiber and a light source, the source disposed remotely from the working end <NUM> and the fiber having a first end optically coupled to the source and a second end disposed at the working end <NUM>. According to the present disclosure, such an emitter <NUM> would still be described as disposed at the working end <NUM> because the light is emitted in the direction of the tissue at the working end <NUM> of the instrument <NUM>. A similar arrangement may be described for the sensor <NUM> wherein an optical fiber has a first end disposed facing the tissue and a second end optically coupled to other components that collectively define the sensor <NUM>.

The system <NUM> may include hardware and software in addition to the emitter <NUM>, sensor <NUM>, and controller <NUM>. For example, where more than one emitter <NUM> is used, a drive controller may be provided to control the switching of the individual emitter elements. In a similar fashion, a multiplexer may be provided where more than one sensor <NUM> is included, which multiplexer may be coupled to the sensors <NUM> and to an amplifier. Further, the controller <NUM> may include filters and analog-to-digital conversion as may be required.

According to certain embodiments, the splitter <NUM> and the analyzer <NUM> may be defined by one or more electrical circuit components. According to other embodiments, one or more processors (or simply, the processor) may be programmed to perform the actions of the splitter <NUM> and the analyzer <NUM>. According to still further embodiments, the splitter <NUM> and the analyzer <NUM> may be defined in part by electrical circuit components and in part by a processor programmed to perform the actions of the splitter <NUM> and the analyzer <NUM>.

For example, the splitter <NUM> may include or be defined by the processor programmed to separate the first pulsatile component from the second non-pulsatile component. Further, the analyzer <NUM> may include or be defined by the processor programmed to determine the presence of (or to quantify the size of, for example) the vessel V within the region <NUM> proximate to the working end <NUM> of the surgical instrument <NUM> based on the pulsatile and/or non-pulsatile component. The instructions by which the processor is programmed may be stored on a memory associated with the processor, which memory may include one or more tangible non-transitory computer readable memories, having computer executable instructions stored thereon, which when executed by the processor, may cause the one or more processors to carry out one or more actions.

As to the operation of such a transmittance-based system to determine tissue and/or artifact (e.g., a vessel, such as a blood vessel or a ureter) characteristics, which characteristics may include position and dimension (e.g., length, width, diameter, etc.) by way of example and not by way of limitation, <CIT> and<CIT> and <CIT> and <CIT>. As to associated structure and operation that may address issues related to the operation of such systems, <CIT> and <CIT>.

<FIG> illustrates an embodiment of the working end <NUM> including both the electrodes <NUM> and the components of the sensor. As illustrated, each of the jaws <NUM>, <NUM> may include one of the electrodes <NUM>. The electrodes <NUM> may be have a central opening to permit light to pass from the light emitter <NUM> in the first jaw <NUM> to the light sensor <NUM> in the second jaw <NUM>. To limit the interaction between the electrodes <NUM> with the remainder of the jaws <NUM>, <NUM> (and the emitters <NUM> and sensors <NUM>), an isolator or insulator <NUM> is disposed between the electrodes and the remainder of the jaw <NUM>, <NUM>.

As mentioned above, other sensors may be used in place of the light-based sensors described above, or may be used in conjunction with the sensors, to provide additional confirmation of the movement of the stimulated tissue or artifact, for example.

One embodiment for use with a jawed surgical instrument involves measuring a change of impedance between the jaws before and after stimulation, and then associating the change of impedance with movement in the tissue between the jaws. Such a sensor may be integrated into the stimulation generator of <FIG>, for example, by including a voltage divider and an analog-to-digital converter. Other alternatives may rely on changes in electrical potential, or changes in resistance.

<FIG> illustrate an embodiment of the surgical system <NUM> in combination with embodiments of a video system <NUM>, such as may be used conventionally during minimally invasive surgery or laparoscopic surgery, for example. The video system <NUM> includes a video camera or other image capture device <NUM>, a video or other associated processor <NUM>, and a display <NUM> having a viewing screen <NUM>.

As illustrated, the video camera <NUM> is directed at the region <NUM> proximate the working ends <NUM> of two surgical instruments <NUM>. As is also illustrated, both of the surgical instruments <NUM> are part of an embodiment of a surgical system <NUM>, such as illustrated in <FIG> and discussed above. In this case, the instruments <NUM> each include a visual indicator or user interface <NUM>, which indicator or interface <NUM> may include a series of bands <NUM>, <NUM> that include light emitting elements <NUM> separated by solid bands <NUM> of shaft <NUM>. It will be recognized, however, that according to other embodiments only one of the instruments <NUM> may include a visual indicator <NUM>. The other elements of the surgical system <NUM> are omitted for ease of illustration, although it will be noted that elements of the system <NUM>, such as the generator <NUM>, the splitter <NUM> and the analyzer <NUM>, may be housed in the same physical housing as the video processor <NUM>, for example.

In the embodiment of <FIG>, the signal from the video camera <NUM> is passed to the display <NUM> via the video processor <NUM>, so that the surgeon or other member of the surgical team may view the region <NUM> as well as the working ends <NUM> of the surgical instruments <NUM>, which are typically inside the patient. Because of the proximity of the visual indicators <NUM> to the working ends <NUM>, and thus the region <NUM>, the visual indicators <NUM> are also visible on the display screen <NUM>. As mentioned previously, this advantageously permits the surgeon to receive visual cues or alarms via the visual indicators <NUM> via the same display <NUM> and on the same display screen <NUM> as the region <NUM> and the working ends <NUM>. This, in turn, limits the need of the surgeon to look elsewhere for the information conveyed via the visual indicators <NUM>.

<FIG> illustrates another embodiment of a video system <NUM> that can be used in conjunction with an embodiment of the surgical system <NUM>. According to this embodiment, the video processor <NUM> is not disposed in a housing separate from the video camera <NUM>', but is disposed in the same housing as the video camera <NUM>'. According to a further embodiment, the video processor <NUM> may be disposed instead in the same housing as the remainder of the display <NUM>' as the display screen <NUM>'. Otherwise, the discussion above relative to the embodiment of the video system <NUM> illustrated in <FIG> applies equally to the embodiment of the video system <NUM> illustrated in <FIG>.

While the user interface <NUM> advantageously permits the surgeon or surgical team to view an output from the controller <NUM>, it is possible to include other output devices with the user interface <NUM>, as illustrated in <FIG>. For example, an alert may be displayed on a video display or monitor <NUM> being used for the surgery (e.g., the display <NUM>, <NUM>' in <FIG>), or may cause an image on the monitor to change color or to flash, change size or otherwise change appearance. The auxiliary output may also be in the form of or include a speaker <NUM> that provides an auditory alarm. The auxiliary output also may be in the form of or may incorporate a safety lockout associated with the surgical instrument <NUM> that interrupts use of the instrument <NUM>. For example, the lockout could prevent ligation or cauterization where the surgical instrument <NUM> is a thermal ligature device. As a still further example, the auxiliary output also may be in the form of a haptic feedback system, such as a vibrator <NUM>, which may be attached to or formed integral with a handle or handpiece of the surgical instrument <NUM> to provide a tactile indication or alarm. In addition to the light emitting elements disposed at the working end <NUM> of the surgical instrument <NUM>, one or more light emitting elements may be disposed at the proximal end <NUM> of the shaft <NUM>, such as disposed on or attached to the grip or handle <NUM>, to provide a visual indication or alarm. Various combinations of these particular forms of the auxiliary output may also be used.

As mentioned above, the surgical system <NUM> may also include the surgical instrument <NUM> with the working end <NUM>, to which the user interface <NUM> and the sensor (and in preferred embodiments, the light emitter <NUM> and the light sensor <NUM>) are attached (in the alternative, removably/reversibly or permanently/irreversibly). The user interface <NUM> and sensor may instead be formed integrally (i.e., as one piece) with the surgical instrument <NUM>. As also stated, it is possible that the user interface <NUM> and sensor be attached to a separate instrument or tool that is used in conjunction with a surgical instrument or tool <NUM>.

As noted above, the surgical instrument <NUM> may be a thermal ligature device in one embodiment. In another embodiment, the surgical instrument <NUM> may simply be a grasper or grasping forceps having opposing jaws. According to still further embodiments, the surgical instrument may be other surgical instruments such as irrigators, surgical staplers, clip appliers, and robotic surgical systems, for example. According to still other embodiments, the surgical instrument may have no other function that to carry the user interface and sensor and to place them within a surgical field. The illustration of a single embodiment is not intended to preclude the use of the system <NUM> with other surgical instruments or tools <NUM>.

In conclusion, although the preceding text sets forth a detailed description of different embodiments of the invention, it should be understood that the legal scope of the invention is defined by the words of the claims set forth at the end of this patent. The detailed description is to be construed as exemplary only and does not describe every possible embodiment of the invention since describing every possible embodiment would be impractical, if not impossible. Numerous alternative embodiments could be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims defining the invention.

Claim 1:
A surgical system (<NUM>) comprising:
an electrical stimulation generator (<NUM>);
at least one sensor (<NUM>) disposed at a working end (<NUM>) of a surgical instrument (<NUM>); and
a controller (<NUM>) coupled to the at least one sensor (<NUM>, <NUM>),
the controller (<NUM>) being configured to:
obtain data from the at least one sensor (<NUM>) over time in response to a stimulation applied by the electrical stimulation generator (<NUM>),
analyze the data obtained from the at least one sensor (<NUM>, <NUM>) over time to generate sensor data analysis results;
apply a signal processing method and/or a pattern matching to the sensor data analysis results; and
indicate if a tissue (T) or artifact is present within a region (<NUM>) proximate to the working end (<NUM>) of the surgical instrument (<NUM>) based on the signal processing method or pattern matching,
characterized in that
the at least one sensor comprises at least one light emitter (<NUM>) and at least one light sensor (<NUM>), the at least one light emitter (<NUM>) and the at least one light sensor (<NUM>) disposed at the working end (<NUM>) of the surgical instrument (<NUM>); and
the controller (<NUM>) comprises a splitter (<NUM>) to separate a pulsatile component from a non-pulsatile component from a signal from the at least one light sensor (<NUM>) and an analyzer (<NUM>) to analyze the pulsatile and/or non-pulsatile component to generate the sensor data analysis results and apply the signal processing method and/or pattern matching to the sensor data analysis results.