System and method used to detect or differentiate tissue or artifact

Abstract

To provide a user interface that embodies advantageous alternative means to existing systems and methods that can provide improved identification for avoiding or isolating tissue or artifacts, such as vessels, without unduly complicating surgical instruments or surgical procedures.SOLUTION: The present patent describes a system and method used to detect or distinguish tissue or artifacts, such as vessels, in particular, a system and method used to detect or distinguish tissue or artifacts, the system including at least one light emitting element and at least one optical sensor disposed at the working end of the shaft.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] This patent relates to a system and method used to detect or distinguish tissue or artifacts, such as vessels, and in particular to a system and method used to detect or distinguish tissue or artifacts, where the system includes at least one light emitting element and at least one light sensor disposed at the working end of the shaft.

[0002] In the surgical field, systems and methods for identifying artifacts, particularly vessels, during a surgical procedure provide valuable information to a surgeon or surgical team. U.S. hospitals lose billions of dollars annually in unreimbursed costs due to inadvertent vascular injury during surgery. Furthermore, affected patients face up to a 32% mortality rate and are likely to be required to remain in the hospital for an additional nine days requiring corrective treatment, resulting in tens, if not hundreds of thousands of dollars in additional medical expenses. As a result, significant value would be gained from methods and systems that allow the surgical field to accurately determine the presence of vessels, such as blood vessels, so that these expenses can be reduced or avoided.

[0003] Systems and methods that provide information regarding the presence of blood vessels in the surgical field are particularly important during minimally invasive surgical procedures. Traditionally, surgeons have relied on touch to identify blood vessels and avoid inadvertent damage to these vessels during surgery. With the shift to minimally invasive procedures such as laparoscopic and robotic surgery, surgeons have lost the ability to use direct visualization and touch to make decisions about the presence of blood vessels in the surgical field. As a result, surgeons are forced to determine whether blood vessels are present in the surgical field primarily based on habit and experience. Unfortunately, anatomical irregularities frequently occur due to congenital abnormalities, scars from previous surgeries, and physical predispositions (e.g., obesity). Under these circumstances, systems and methods that allow surgeons to determine the presence and / or characteristics of vessels in the surgical field during surgery (possibly in real time or near real time) would be of great advantage.

[0004] On the other hand, it would be advantageous to have systems and methods that provide information regarding the presence of blood vessels within a surgical field, but would be hindered in their adoption if they made the surgical procedure more complicated.Thus, it would be advantageous for the systems and methods to not involve significant thought by the surgeon or surgical team in using the system or method to detect or distinguish tissues or artifacts such as blood vessels, or significant preparation of the surgical field or patient for use of the system or method.

[0005] As described in further detail below, the present invention describes a user interface that embodies an advantageous alternative to existing systems and methods that can provide improved discrimination to avoid or isolate tissues or artifacts, such as vessels, without unduly complicating the surgical instruments or surgical procedure. Summary of the Invention [Problem to be solved by the invention]

[0006] According to one aspect of the present disclosure, a surgical system includes a surgical instrument, at least one light emitting element disposed at a working end of the surgical instrument, an array of optical sensors disposed at the working end of the surgical instrument, where each optical sensor in the array of optical sensors is adapted to generate a signal including a non-pulsatile component, and a controller coupled to the array of optical sensors, the controller including an analyzer configured to determine a curve of the non-pulsatile component of the signal of each of the individual optical sensors in the array of optical sensors, smooth the curve to generate a smoothed curve, calculate a derivative of the smoothed curve, invert the smoothed curve to generate an inverse smoothed curve, calculate a derivative of the inverse smoothed curve, take a difference between the derivative of the inverse smoothed curve and the derivative of the smoothed curve to generate a resultant curve, smooth the resultant curve to generate a smoothed resultant curve, estimate zero crossings of the smoothed resultant curve, apply a sign function to points adjacent each zero crossing, if present, to generate a resultant, and identify a region of interest, if present, based on the result of the points adjacent each zero crossing, if present. [Brief description of the drawings]

[0007] The present invention will be more fully understood from the following description in conjunction with the accompanying drawings, in which: Some of the figures may be simplified by omitting selected components to more clearly show other components. Such omission of components in some of the figures does not necessarily indicate the presence or absence of the particular components in any of the example embodiments, unless expressly defined in the corresponding written description. None of the figures are necessarily drawn to scale.

[0008] [Figure 1] FIG. 1 is a schematic diagram of a surgical system according to one embodiment of the present invention. [Diagram 2] FIG. 2 is an enlarged partial view of a transmittance-based embodiment of the surgical instrument of FIG. 1 with a light-emitting element and a light sensor, with a portion of the vessel shown disposed between the light-emitting element and the light sensor. [Diagram 3] FIG. 3 is an enlarged partial view of an embodiment of the surgical instrument of FIG. 1 also equipped with a reflectance-based system with fixedly spaced light sensors and light emitters, with a portion of the vessel shown in close proximity to the light emitters and light sensors. [Figure 4] FIG. 4 is an enlarged partial view of another embodiment of a surgical instrument also equipped with a reflectance-based system having an optical sensor and an optical emitter with adjustable spacing relative to one another, with a portion of a blood vessel shown in close proximity to the optical emitter and the optical sensor. [Diagram 5] FIG. 5 is a schematic diagram of a surgical system according to one embodiment of the invention in combination with an embodiment of a video system illustrating the surgical system used with a video system. [Figure 6] FIG. 6 is a schematic diagram of a surgical system according to one embodiment of the invention in combination with another embodiment of a video system illustrating a surgical system used with a video system. [Figure 7]FIG. 7 is a flowchart of a method used by any of the systems described above to detect or distinguish one or more regions of interest in a signal received from an array of optical sensors, where the detection or distinction of the one or more regions of interest may result in the detection or distinction of tissue or one or more artifacts. [Figure 8] FIG. 8 is a flow chart of a method used by any of the above-mentioned systems to select from among a plurality of regions of interest those regions of interest that are more or less likely to be associated with an artifact, such as a vessel. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The embodiments described herein provide systems and methods for detecting or distinguishing regions of interest within curves, including detecting or distinguishing tissues or artifacts such as blood vessels, that can be used with or in a surgical system or surgical instrument. Such a system can include at least one light emitting element disposed at a working end of the surgical instrument, and an array of optical sensors disposed at the working end of the surgical instrument, where each optical sensor in the array of optical sensors is adapted to generate a signal that includes a non-pulsatile component. The system can include a controller coupled to the array of optical sensors, where the controller includes an analyzer. The analyzer is configured to determine a curve of a non-pulsating component of the signal of each individual optical sensor in the array of optical sensors, smooth the curve to generate a smoothed curve, calculate a derivative of the smoothed curve, invert the smoothed curve to generate an inverse smoothed curve, calculate a derivative of the inverse smoothed curve, take a difference between the derivative of the inverse smoothed curve and the derivative of the smoothed curve to generate a result curve, smooth the result curve to generate a smoothed result curve, estimate zero crossings of the smoothed result curve, apply a sign function to points adjacent each zero crossing, if present, to generate a result, and identify a region of interest, if present, based on the results of the points adjacent each zero crossing, if present.

[0010] Turning first to Figures 1-6, an embodiment of such a surgical system 100 is illustrated. The system 100 may be used, for example, to determine characteristics (e.g., presence, diameter, etc.) of a vessel V within a region 102 of tissue T proximate a working end 104 of a surgical instrument 106. It will be appreciated that the vessel V may be connected to other vessels along with the region 102 of tissue T, and further, the vessel V may extend beyond the region 102 to be in fluid communication with other organs (e.g., the heart) also found within the patient's body. Additionally, while the tissue T appears in Figures 1-4 to completely surround (both in perimeter and length) the vessel V to a certain depth, this need not be the case in all instances of using the system 100. For example, the tissue T may only partially surround the perimeter of the vessel V and / or surround only a portion of the length of the vessel V, or the tissue T may have a very thin layer covering the vessel V. As a further example, vessel V may be a blood vessel and tissue T may be, but is not limited to, connective tissue, adipose tissue and / or liver tissue.

[0011] According to the illustrated embodiment, the working end 104 of the surgical instrument 106 is also the distal end of the shaft 108. Thus, the working end and the distal end are referred to as the working end 104 or the distal end 104. The shaft 108 also has a proximal end 110 at which a grip or handle 112 (interchangeably referred to herein as the grip 112) is disposed. The grip 112 is designed according to the nature of the instrument 106; for the thermal ligation device illustrated in FIG. 1, the grip 112 may be a pistol-style grip including a trigger 114. As an option, a finger ring disposed on a generally scissor-style grip may be used.

[0012] Although the working or distal end 104 and the proximal end 110 having the grip 112 are shown as being located at opposite extreme ends of the shaft 108, it will be appreciated that certain surgical instruments have a working end (e.g., where a tool tip is attached) located at the opposite extreme ends of the shaft and a gripping area located intermediate the opposite working ends. In accordance with the terms "distal" and "proximal" used herein, the working end of such an instrument is referred to herein as the distal end and the gripping area is referred to as the proximal end. However, for the illustrated embodiment, the distal and proximal ends are located at opposite extreme (or simply opposite) ends of the shaft 108.

[0013] As mentioned above, according to the illustrated preferred embodiment, the surgical system 100 comprises a sensor having at least one light emitting element 120 (or simply light emitting element 120) and one or more light sensors or detectors 122 (or simply light sensor 122). See Figures 2-4. According to the illustrated embodiment, a controller 124 is coupled to the light emitting element 120 and the light sensor 122, which may comprise a splitter 126 and an analyzer 128, as described below. See Figure 1.

[0014] The light emitting element 120 is disposed at the working end 104 of the surgical instrument 106. The light sensor 122 is also disposed at the working end 104 of the surgical instrument 106. In either case, the phrase "disposed" may refer to the physical placement of the light emitting element 120 or light sensor 122 at the working end 104, or the placement of an optical fiber or other light guide at the working end 104. The light guide is coupled to the light emitting element 120 or light sensor 122, and thus the light emitting element 120 or light sensor 122 may be disposed elsewhere. The system 100 may operate according to a transmittance-based approach, such that the light sensor 122 is disposed opposite and facing the light emitting element 120, such as, for example, on the opposite jaw of the surgical instrument 106 as shown in FIG. 2. It should be noted that system 100 may include a reflectance-based system (for forward-facing vessel and / or tissue detection) such that light emitting element 120 and light sensor 122 face in a common direction and may have a fixed spacing therebetween, such as on a single jaw of a two-jaw device (see FIG. 3). Alternatively, light emitting element 120 and light sensor 122 of a reflectance-based system may be configured such that the spacing between light emitting element 120 and light sensor 122 is adjustable, such as by disposing light emitting element 120 at an end or tip of one jaw of a two-jaw device and light sensor 122 at an end or tip of the other jaw of the two-jaw device (see FIG. 4). Regarding the operation of such reflectance-based systems, PCT Application No. PCT / US17 / 17436, filed February 10, 2017, is incorporated herein by reference in its entirety.

[0015] The light emitting element 120 may be configured to emit light having at least one wavelength. For example, the light emitting element 120 may emit light having a wavelength of 660 nm. This may be accomplished with a single element or with multiple elements (which may be arranged or configured, for example, in an array, as described in more detail below). In a similar manner, the light sensor 122 is configured to detect light of at least one wavelength (e.g., 660 nm). According to embodiments described herein, the light sensor 122 includes multiple elements, which may be arranged or configured in an array.

[0016] According to certain embodiments, the light emitting element 120 can be configured to emit light at least two different wavelengths and the light sensor 122 can be configured to detect light at least two different wavelengths. As an example, the light emitting element 120 can emit light in the visible range and the light sensor 122 can be configured to detect light in the near infrared range or the infrared range. Specifically, the light emitting element 120 can emit light and the light sensor 122 can detect light at 660 nm and 910 nm. Such an embodiment can be used, for example, to ensure optimal penetration of a blood vessel V and surrounding tissue T under in vivo conditions.

[0017] Depending on the effect of changes in blood flow, a third wavelength of light may be emitted and detected. That is, if the detection method is found to be sensitive to changes in blood flow velocity in the blood vessel of interest, light at 810 nm (i.e., the isosbestic point) may be emitted and detected to normalize the results to limit or eliminate the effect of changes in blood flow velocity. Additional wavelengths of light may be used.

[0018] According to some embodiments, the individual optical sensors 122 are configured to generate a signal including a first pulsating component and a second non-pulsating component. It will be appreciated that the first pulsating component may be an alternating current (AC) component of the signal and the second non-pulsating component may be a direct current (DC) component. If the optical sensors 122 are in the form of an array, the pulsating and non-pulsating information may be generated for each element of the array, or for at least elements of the array defining at least one column of the array.

[0019] With respect to the pulsatile component, it will be appreciated that blood vessels can be described as having a characteristic pulsation of about 60 pulses (or beats) per minute. Although this may vary depending on the age and condition of the patient, the pulsation range is typically from about 60 to about 100 pulses (or beats) per minute. The optical sensor 122 generates a signal (which is passed to the controller 124) having a particular AC waveform corresponding to the movement of blood through the blood vessel. In particular, the AC waveform corresponds to light absorbed or reflected by the pulsating blood flow within the blood vessel. Meanwhile, the DC component corresponds primarily to light absorbed, reflected, and / or scattered by tissue, so that the blood vessel may appear as a "shadow" or "dip" in the curve formed by the DC signals from each of the sensors in the sensor array.

[0020] According to such an embodiment, the controller 124 may include a splitter 126 coupled to the optical sensor 122 and for separating the first pulsating component and the second non-pulsating component for each element of the optical sensor array 122. The controller 124 may also include an analyzer 128 for determining the presence and / or characteristics of a vessel V in the region 102 proximate the working end 104 of the surgical instrument 106 based (at least in part) on the pulsating component. According to embodiments described herein, the analyzer may make this determination by first detecting or identifying a region of interest in the DC signal from the optical sensor 120 of the system 100.

[0021] Before discussing the details of determining the region of interest, further details of the system may be discussed with reference to, for example, the transmittance-based embodiment of Figs. 1 and 2. The light emitting element 120 may include one or more elements, as described above. According to the embodiment shown diagrammatically in Fig. 2, the light sensor 122 may comprise a first light emitting element 120-1, a second light emitting element 120-2, and a third light emitting element 120-3. All of the light emitting elements may be configured to emit light at a particular wavelength (e.g., 660 nm), or a particular light emitting element may emit light at a different wavelength than the other light emitting elements. Each light emitting element may be, for example, a light emitting diode.

[0022] For embodiments in which the light emitting element 120 is in the form of an array comprising one or more light emitting diodes, as shown in FIG. 2, the diodes can be arranged in a one-dimensional array, a two-dimensional array, or a three-dimensional array. An example of a one-dimensional array can include arranging the diodes along a line in a single plane, and an example of a two-dimensional array can include arranging the diodes in multiple columns and rows in a single plane. A further example of a two-dimensional array can include arranging the diodes on a curved surface or along a line in a curved surface. A further example of a three-dimensional array can include diodes arranged in multiple planes, e.g., multiple columns and rows, on or in a curved surface.

[0023] 2, the light sensor 122 may include a first light sensor 122-1, a second light sensor 122-2, an n-th light sensor 122-n, etc. As with the light emitting elements 120-1, 120-2, 120-3, the light sensors 122-1, 122-2, 122-3, 122-n may be arranged in an array, and the discussion of arrays above applies here as well.

[0024] In fact, if the array of photosensors 122 includes rows of photosensors (as in FIG. 2), the array 122 can alternatively be referred to as a linear array. The individual photosensors 122 of the array 122 can be located adjacent to one another, or the photosensors can be spaced apart from one another. The individual photosensors that define a row of photosensors may be separated from one another by photosensors that define different array rows or columns. However, according to certain embodiments, the array may comprise a charge-coupled device (CCD), in particular a linear CCD imaging device that includes a plurality of pixels. Alternatively, a CMOS sensor array may be used.

[0025] The system 100 can include hardware and software in addition to the light emitting elements 120, the sensors 122, and the controller 124. For example, if more than one light emitting element 120 is used, a drive controller can be provided to control the switching of the individual light emitting elements. Similarly, if more than one sensor 122 is included, a multiplexer can be provided, which can be coupled to the sensors 122 and amplifiers. Additionally, the controller 124 can include filters and analog-to-digital conversion as needed.

[0026] According to certain embodiments, splitter 126 and analyzer 128 can be defined by one or more electrical circuit components. According to other embodiments, one or more processors (or simply processors) can be programmed to perform the operations of splitter 126 and analyzer 128. According to further embodiments, splitter 126 and analyzer 128 can be defined in part by electrical circuit components and in part by a processor programmed to perform the operations of splitter 126 and analyzer 128.

[0027] For example, the splitter 126 may include or be defined by a processor programmed to separate the first pulsatile component from the second non-pulsatile component. Additionally, the analyzer 128 may include or be defined by a processor programmed to determine the presence (or, for example, quantify the size) of a vessel V in the region 102 proximate the working end 104 of the surgical instrument 106 based on the first pulsatile component. The instructions by which the processor is programmed may be stored on a memory associated with the processor, which may include one or more tangible, non-transitory, computer-readable memories having computer-executable instructions stored therein that, when executed by the processor, cause the one or more processors to perform one or more operations.

[0028] For operation of such transmittance-based systems to determine characteristics (which may include location and dimensions (e.g., length, width, diameter)) of tissue and / or artifacts (e.g., vessels such as blood vessels or ureters), see, by way of example and not by way of limitation, U.S. Publication Nos. 2015 / 0066000, 2017 / 0181701, 2018 / 0042522, and 2018 / 0098705, each of which is incorporated herein by reference in its entirety. For related structure and operation that may address issues related to the operation of such systems, PCT Application Nos. PCT / US16 / 55910, filed October 7, 2016, and PCT / US17 / 48651, filed August 25, 2017, each of which is incorporated herein by reference in its entirety.

[0029] 5 and 6 illustrate an embodiment of the surgical system 100 in combination with an embodiment of a video system 200, such as may be used during conventional, minimally invasive or laparoscopic surgery. The video system 200 includes a video camera or other image capture device 202, a video or other associated processor 204, and a display 206 having a display screen 208.

[0030] As shown, the video camera 202 is directed at the area 102 proximate the working ends 104 of the two surgical instruments 106. As shown, both of the surgical instruments 106 are part of the embodiment of the surgical system 100 as illustrated in FIG. 2 and discussed above. In this case, the instruments 106 each include a visual indicator 130. However, it will be appreciated that according to other embodiments, only one of the instruments 106 may include a visual indicator 130. It is noted that for ease of illustration, other components of the surgical system 100 are omitted, although components of the system 100, such as the splitter 126 and analyzer 128, may be housed within the same physical housing as the video processor 204.

[0031] The signal from the video camera 202 is passed through a video processor 204 to a display 206, which allows the surgeon or other members of the surgical team to view the area 102, which is typically inside the patient, as well as the working end 104 of the surgical instrument 106. Because the visual indicator 130 is in close proximity to the working end 104, and thus the area 102, the visual indicator 130 is also visible on the display screen 108. As mentioned above, this advantageously allows the surgeon to receive a visual cue or alert via the visual indicator 130 via the same display 206 and the same display screen 208 as the area 102 and working end 104. This, in turn, limits the need for the surgeon to look elsewhere for information conveyed via the visual indicator 130.

[0032] 6 illustrates another embodiment of a video system 200 that can be used in connection with an embodiment of the surgical system 100. According to this embodiment, the video processor 204 is not located in a separate housing from the video camera 202', but is located in the same housing as the video camera 202'. According to a further embodiment, the video processor 204 can instead be located in the same housing as the remainder of the display 206' as the display screen 208'. Otherwise, the above description related to the embodiment of the video system 200 illustrated in FIG. 5 applies equally to the embodiment of the video system 200 illustrated in FIG. 6.

[0033] While the user interface 130 advantageously allows the surgeon or surgical team to view the output from the controller 124, it is possible for the user interface 130 to include other output devices, as shown in Figures 1 and 2. For example, an alert may be displayed on the video monitor 300 (e.g., displays 206, 206' in Figures 5 and 6) being used in the procedure, or the alert may cause the image on the monitor to change color, flash, change size, or otherwise change appearance. The auxiliary output may also be in the form of or include a speaker 302 that provides an audible alarm. The auxiliary output may also be in the form of or incorporate a safety lockout associated with the surgical instrument 106 that suspends use of the surgical instrument 106. For example, the lockout may prevent ligation or cauterization if the surgical instrument 106 is a thermal ligation device. As yet a further example, the auxiliary output may be in the form of a tactile feedback system, such as a vibrator 304, which may be attached to or integral with the handle or handpiece of the surgical instrument 106 to provide a tactile indication or alarm. In addition to the light emitting devices located at the working end 104 of the surgical instrument 108, one or more light emitting devices may be located at the proximal end 110 of the shaft 108, such as located or attached on the grip or handle 112, to provide a visual indication or alarm. Various combinations of these particular forms of auxiliary outputs may be used.

[0034] As noted above, the surgical system 100 may also include a surgical instrument 106 with a working end 104 to which a user interface 130 and a sensor (and in a preferred embodiment, the light emitting element 120 and the light sensor 122) are attached (alternatively, removably / reversibly or permanently / irreversibly). Alternatively, the user interface 130 and the sensor may be integrally (i.e., one piece with) formed with the surgical instrument 106. As also noted, the user interface 130 and the sensor can be attached to a separate instrument or tool that is used in combination with the surgical instrument or tool 106.

[0035] As noted above, in one embodiment, the surgical instrument 106 can be a thermal ligation device. In another embodiment, the surgical instrument 106 can simply be a grasper or grasping forceps with opposing jaws. According to yet additional embodiments, the surgical instrument can be other surgical instruments, such as, for example, an irrigator, a surgical stapler, a clip applier, a robotic surgical system, etc. According to still other embodiments, the surgical instrument may have no other functionality other than to hold the user interface and sensors and position them within the surgical field. The illustration of a single embodiment does not preclude the use of the system 100 with other surgical instruments or tools 106.

[0036] In the context of one or more of the systems described above, it will be appreciated that identification of a region of interest is important as a preliminary to characterizing an artifact (e.g., determining a vessel diameter) from data received from an array of optical sensors. Furthermore, it is advantageous that the identification of a region of interest is relatively robust compared to environmental factors that may affect the identification of the region of interest. It is also advantageous that the identification of a region of interest minimizes the computational burden to perform the identification. In conjunction with the former, identification systems and methods that minimize the computational burden may also facilitate the use of the systems and methods in real-time or near real-time implementations.

[0037] As described above, the system 100 described includes a light emitting element 120 and a light sensor 122, and the signal from the light sensor may include a pulsating (or AC) component and a non-pulsating (or DC) component. The systems and methods for identifying a region of interest described herein utilize the non-pulsating or DC component. This DC data may be described in terms of a DC curve that includes DC data from a plurality of light sensors arranged in an array (e.g., a linear array, etc.) according to at least one embodiment described herein.

[0038] In general, the method shown in FIG. 7 may be used to determine regions of interest where a "dip" occurs in the DC curve (i.e., a region along the DC curve where the profile decreases and then increases). According to certain embodiments, all dips may be identified as regions of interest. According to other embodiments, the regions of interest may then be further processed to determine which of the regions of interest are more likely (or more likely) to be associated with a particular artifact, such as a vessel, particularly a blood vessel. For example, regions of interest that are more likely (or more likely) to be associated with a blood vessel may be separated from regions of interest associated with foreign or highly absorbing tissue. In this manner, the method may be used to locate and track blood vessels along the sensor array in real time.

[0039] As described with reference to FIG. 7, a method 300 for identifying an area of ​​interest is described, which can be used in the embodiment of the system 100 described above. The embodiment of the method 300 shown in FIG. 7 begins at block 302, where the system 100 controls the light emitting element 120 to emit light of one or more wavelengths. The method 300 continues at block 304, where the light sensor 122 receives light and generates a signal according to the detected light. It will be appreciated that while a significant portion of the light received by the light sensor 122 is likely from the light emitting element 120, ambient light (i.e., light from other light sources) may also contribute to the light received by the light sensor 122. Furthermore, consistent with the above discussion, the light received by the light sensor 122 may include pulsatile and non-pulsatile components, especially when the light is received after passing through tissue that includes a vessel such as a blood vessel.

[0040] At block 306, system 100 separates the signal received from optical sensor 122 into a pulsating component and a non-pulsating component. For example, splitter 126 may be used to separate the different components of the signal. Additionally, while method 300 utilizes the non-pulsating (or DC) component, it will be appreciated that a pulsating (or AC) component may similarly be utilized by system 100, either separately or in combination with the output of method 300.

[0041] According to one embodiment of the method 300, the system 100 smooths the DC curve (which may include DC signals corresponding to each of the photosensors 122 along the array). In this regard, the smoothing may include filtering, which may also include averaging. Smoothing the DC curve helps to focus on the sensor that produces a signal that has the most distinct DC signal compared to the other sensors.

[0042] At block 310, the system 100 determines a derivative of the smoothed DC curve (Smoothed DC Curve) generated at block 308. In particular, the system 100 determines the derivative using three-point numerical differentiation, although other n-point numerical differentiation may be used instead. The system 100 determines the derivative using numerical differentiation to reduce the computational burden caused by the method 300.

[0043] At block 312, the system 100 inverts the smoothed signal determined at block 308. At block 314, the system 100 determines the derivative of the inverted smoothed DC curve (the unsmoothed DC curve). As in block 310, the system may determine the derivative by using, for example, three-point numerical differentiation. Again, the use of numerical differentiation may reduce the computational burden of the method 300.

[0044] At block 316, the system 100 subtracts the derivative determined at block 314 from the derivative determined at block 310. The system 100 then smooths the result of this subtraction at block 316 (called a result curve) to generate a smoothed result curve (smoothed result curve) at block 318. The system 100 then interpolates the smoothed result curve at block 320 for use in the remainder of the method 300. Optionally, the smoothed result curve may be used in the remainder of the method 300.

[0045] At block 322, the system 100 estimates the zero crossings of the smoothed (and optionally interpolated) resulting curve. The system 100 then applies a sign function to points adjacent to the estimated zero crossings of the resulting curve at block 324, and determines at block 326 whether the results of applying the sign function to the adjacent points exhibit a particular pattern. In particular, the system 100 may analyze the results for a pattern of [1,-1,1], [1,-1], [-1,1] for the points adjacent to the zero crossings. This pattern suggests that a dip has occurred in the original signal curve. The system 100 then identifies this region as a region of interest at block 328.

[0046] 7, the system may identify multiple regions of interest at block 328. That is, based on the number of zero crossings and the patterns established for the points adjacent to those zero crossings, the system may identify zero regions of interest, one region of interest, or multiple regions of interest. In identifying multiple regions of interest, the decision at block 328 may be repeated or made multiple times.

[0047] As further reflected in method 300 of FIG. 7, in situations where multiple regions of interest are determined at block 328, system 100 may perform additional actions at block 330 to select one or more regions of interest from the multiple regions determined at block 328. For example, in some embodiments, a particular region of interest may be selected based on the likelihood that a vessel is associated with that region compared to other regions. In other embodiments, all of the regions of interest may be considered, for example, when attempting to identify different tissues. System 100 then performs further analysis on one or more regions of interest at block 332, such as determining a size (e.g., diameter or effective diameter) of a vessel associated with those regions of interest, such as according to the methods disclosed in the references incorporated herein by reference in their entireties.

[0048] As an example of actions that may be performed to select one or more regions of interest from a plurality of identified regions of interest, method 350 is illustrated in FIG. 8. This method may be used to determine which regions of interest are likely or unlikely to have a vessel (e.g., a blood vessel such as an artery or vein) associated therewith. In general, method 350 first determines which regions of interest are likely to overlap and resolves whether the overlapping regions of interest should be treated as a single region of interest or as separate regions of interest. After resolving the overlap issue, method 350 then attempts to determine whether each of the remaining regions of interest is likely or unlikely to be associated with a vessel. As described above, after performing method 350, a plurality of regions may be identified as regions of interest that may be further processed.

[0049] Method 350 begins at block 352 where a determination is made whether any of the regions of interest overlap. This determination can be made if the start point of a region of interest is between the start point and end point of another region of interest and / or if the end point or region of interest is between the start point and end point of another region of interest. As explained above, the start and end points of the regions of interest can be determined by comparing the results of a sign function. If there are overlapping regions of interest, method 350 continues to block 354; if there are no overlapping regions of interest, method 350 continues to block 362.

[0050] If at least two regions of interest are determined to overlap at block 352, then a proximity analysis of the regions of interest is performed at block 354. In general, if the regions of interest are close enough such that no two vessels are actually close enough, system 100 may treat them as a single region of interest; otherwise, the regions may be treated as separate regions. According to one embodiment, the proximity determination may include: 1) determining the proximity between the end points of adjacent regions; 2) determining the proximity between the start point of a region and the end point of the previous region; and 3) determining the proximity between the start points of adjacent regions. That is, D is:

number

number

[0051] After resolving the overlapping region problem, method 350 continues to determine which of the remaining regions are more or less likely to be associated with an artifact, such as a vessel. This determination can answer either or both of these questions (i.e., more or less likely), but the goal is to identify more likely regions of interest for further processing. Method 350 of FIG. 8 includes one embodiment for making this determination, although other embodiments are also possible for making this determination.

[0052] According to method 350, a number of parameters are analyzed in block 362 to determine whether each of the regions of interest is likely (or unlikely) to be associated with a vessel. Each of the parameters may be analyzed in block 364 to determine whether the parameter is met, such as by comparing the parameter to a threshold value associated with that parameter. After each parameter is compared to its respective threshold value, the results of all comparisons may be analyzed in block 366 to determine whether a vessel is likely to be present, such as by comparing the analysis performed in block 364 to further criteria. The determination made in block 366 is then provided as an output in block 368 for purposes of identifying regions of interest for further processing, such as as part of method 300 of FIG. 7. It will be appreciated that the operations of blocks 362, 364, 366, 368 may be repeated as necessary to address all of the identified regions of interest.

[0053] In the embodiment of FIG. 8, the following five parameters are considered: 1) width, 2) standard deviation of the derivative of the region of interest, 3) average value of the derivative of the individual values ​​of the sensor associated with the region of interest / standard deviation of the derivative of the individual values ​​of the sensor associated with the region of interest, 4) minimum value among the individual values ​​of the sensor associated with the region of interest, and 5) standard deviation for the individual values ​​of the sensor associated with the region of interest / average value of the individual values. According to other embodiments, other parameters may be considered and the total number of parameters may be more or less than five. These parameters may be determined in a particular order in block 362 or may be determined simultaneously or nearly simultaneously. The method 350 may determine each parameter separately and proceed immediately to the analysis of the parameters in block 364, or may determine all parameters (sequentially or simultaneously / near simultaneously) in block 362 and then proceed to block 364.

[0054] At block 364, the parameter determined at block 362 is analyzed to determine whether the parameter indicates that a vessel is more or less likely to be associated with the region of interest. For example, the width parameter may be compared to a minimum width, which represents a practical limit on the size of an expected vessel or vessel of interest. As noted above, the use of a threshold comparison is not the only analytical method that can be used to determine whether a parameter is more or less likely to indicate a vessel is present in the region of interest.

[0055] At block 366, it is determined whether a vessel is likely or unlikely to be associated with the region of interest based on the analysis at block 364 of each of the parameters determined at block 362. For example, according to the present embodiment, the determination of whether a vessel is likely to be present requires that all parameters be satisfied. According to other embodiments, it may be sufficient, for example, for a simple majority of the parameters to exceed an associated threshold. Still other embodiments may use a weighted average of the results of the parameter comparison. In any case, after the determination is made at block 366, a result is provided at block 368.

[0056] After the system 100 has determined the region of interest to evaluate, such as by using a method as shown in FIG. 8, the system 100 may characterize the artifact at block 332 of FIG. 7. For example, the characterization that occurs at block 332 may include determining whether the artifact is a vessel, and if so, whether the vessel is a particular type of vessel (e.g., an artery). Alternatively, the characterization that occurs at block 332 may be between different types of tissue. As a further alternative, the characterization may include determining a dimension of the artifact: for example, if the artifact is a vessel, the dimension may be a diameter (if the vessel is considered or assumed to be circular in cross-section) or an effective diameter (if the vessel is considered or assumed to be other than circular in cross-section, the maximum dimension of the entire vessel may be used instead of the actual diameter).

[0057] In this regard, one or more actions performed by system 100 in block 332 to determine characteristics (which may include location and dimensions (e.g., length, width, diameter, etc.)) of tissue and / or artifacts (e.g., vessels such as blood vessels or ureters) may include, by way of example and not limitation, those described for transmittance-based systems in U.S. Publication Nos. 2015 / 0066000, 2017 / 0181701, 2018 / 0042522, and 2018 / 0098705, each of which is incorporated herein by reference in its entirety.

[0058] In conclusion, although the above description provides a detailed description of different embodiments of the present invention, it should be understood that the legal scope of the present invention is defined by the language of the claims attached to this application. The detailed description should be construed as merely exemplary and does not describe all possible embodiments of the present invention, as describing all possible embodiments of the present invention would be impractical, if not impossible. Using current technology or technology developed after the filing date of this application, numerous other embodiments can be implemented that would still fall within the scope of the claims that define the present invention.

[0059] It should also be understood that unless a term is expressly defined in the present invention using "As used herein, the term 'shall mean'" or similar language, there is no intention to explicitly or implicitly limit the meaning of the term beyond its plain or ordinary meaning, and such terms should not be construed as limited in scope based on any statement made in any section of the present invention (other than the language of the claims). To the extent that terms referred to in the claims appended hereto are referred to in the present invention in a manner consistent with a single meaning, which is done solely for clarity to avoid confusing the reader, it is not intended to limit such claim terms to that single meaning by implication or otherwise. Finally, the scope of any claim element is not intended to be construed under application of 35 USC § 112(f) unless the claim element is defined by reciting the term "means" and a function without reciting any structure.

Claims

1. 1. A surgical system including a surgical instrument, comprising: at least one light emitting element disposed on a working end of the surgical instrument; an array of optical sensors disposed at a working end of the surgical instrument, each optical sensor within the array of optical sensors adapted to generate a signal including a non-pulsatile component; a controller coupled to the array of photosensors; Equipped with the controller comprises an analyzer; The analyzer comprises: determining a curve of the non-pulsatile component of the signal for each of the optical sensors in the array of optical sensors; smoothing the curve to generate a smoothed curve; Calculating the derivative of the smoothed curve; inverting the smoothed curve to generate an inverse smoothed curve; Calculating the derivative of the inverse smoothed curve; taking the difference between the derivative of the inverse smoothed curve and the derivative of the smoothed curve to generate a result curve; smoothing the resultant curve to generate a smoothed resultant curve; estimating zero crossings of the smoothed resultant curve; If present, apply the sign function to the points adjacent to each zero crossing to produce a result; Identifying a region of interest, if any, based on said results for points adjacent to each zero crossing, if any. It is configured as follows: Surgical systems.

2. the analyzer is configured to calculate a three-point differential of the smoothed curve to calculate the derivative of the smoothed curve. The surgical system of claim 1 .

3. the analyzer is configured to calculate a three-point differential of the inverse smoothed curve to calculate the derivative of the inverse smoothed curve. The surgical system of claim 1 .

4. the analyzer is configured to interpolate the smoothed resultant curve before estimating zero crossings of the smoothed resultant curve. The surgical system of claim 1 .

5. the analyzer is configured to identify a plurality of regions of interest based on the results of points adjacent each zero crossing, identify a region from the plurality of regions of interest, and characterize an artifact associated with the region. The surgical system of claim 1 .

6. The controller comprises a processor and a memory; The analyzer determines a curve of the non-pulsatile component of the signal of each individual optical sensor in the array of optical sensors, smooths the curve to generate a smoothed curve, calculates a derivative of the smoothed curve, inverts the smoothed curve to generate an inverse smoothed curve, calculates a derivative of the inverse smoothed curve, takes a difference between the derivative of the inverse smoothed curve and the derivative of the smoothed curve to generate a result curve, smooths the result curve to generate a smoothed result curve, estimates zero crossings of the smoothed result curve, applies a sign function to points adjacent each zero crossing, if present, to generate a result, and identifies a region of interest, if present, based on the result at points adjacent each zero crossing, if present. The processor is programmed to: The surgical system of claim 1 .

7. the analyzer is configured to characterize an artifact based on the identified region of interest. The surgical system of claim 1 .

8. the analyzer is configured to determine a diameter or an effective diameter of a vessel based on the identified region of interest. The surgical system of claim 7.

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