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Researchers Submit Patent Application, "System and Method for Detecting Critical Structures Using Ultrasound", for Approval

February 6, 2014



By a News Reporter-Staff News Editor at Politics & Government Week -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventors ZHENG, PENG (LONGMONT, US); VALENTINE, CHRISTOPHER A. (BOULDER, CO); RUSIN, CHRISTOPHER T. (GOLDEN, CO); ROOKS, KATHY E. (AURORA, CO); CORUM, BENJAMIN M. (BOULDER, CO); JANDRALL, SALLY D. (EVERGREEN, CO); JOHNSON, KRISTIN D. (LOUISVILLE, CO), filed on March 15, 2013, was made available online on January 23, 2014.

The patent's assignee is Covidien Lp.

News editors obtained the following quote from the background information supplied by the inventors: "A hemostat or forceps is a simple pliers-like tool that uses mechanical action between its jaws to constrict vessels and is commonly used in open surgical procedures to grasp, dissect and/or clamp tissue. Electrosurgical forceps utilize both mechanical clamping action and electrical energy to affect hemostasis by heating the tissue and blood vessels to coagulate, cauterize and/or seal tissue.

"Over the last several decades, more and more surgeons are replacing traditional open methods of gaining access to vital organs and body cavities with endoscopes and endoscopic/laparoscopic techniques and instruments that access organs through small puncture-like incisions. Endoscopic instruments are inserted into the patient through a cannula, or port that has been made with a trocar. Typical sizes for cannulae range from three millimeters to twelve millimeters. Smaller cannulae are usually preferred, which, as can be appreciated, ultimately presents a design challenge to instrument manufacturers who must find ways to make surgical instruments that fit through the cannulae.

"By utilizing an electrosurgical instrument, a surgeon can cauterize, coagulate/desiccate and/or simply reduce or slow bleeding, by controlling the intensity, frequency and duration of the electrosurgical energy applied through the jaw members to the tissue. Typically, electrodes, housed in each of the jaw members are charged to a different electric potential such that when the jaw members grasp tissue, electrical energy can be selectively transferred from one electrode to the other and through the tissue.

"Bipolar electrosurgical instruments are known in the art. Commonly-owned U.S. Patent Application Publication No. 2007-0062017, discloses an exemplary bipolar electrosurgical instrument. Conventional bipolar electrosurgical instruments may include a cutting blade, fluid applicator, stapling mechanism or other like feature, in various combinations.

"During certain procedures, surgeons must identify certain anatomical structures such as large vasculature, bile ducts, or urinary ducts such as the ureter. These structures often need to be avoided or in some instances ligated during a procedure, thus requiring a high degree of confidence when identifying such structures so that they can be properly avoided or ligated as the situation may merit. In surgery (open or laparoscopic), the surgeon is constantly relating the visualized anatomy they are currently operating on or near to known text book anatomy. This task is most difficult when the target anatomy (or that to be avoided) is obscured by overlying soft tissue. As such, the ability to 'see' what lies below the visual tissue surface is desired.

"One issue during laparoscopic procedures in particular, is inadvertently injuring nearby critical anatomical structures due to quick or abrupt movement of instruments within the surgical site, poor visibility, lack of tactile response, confusion of the anatomy from patient to patient, or inadequate control of the instrumentation being utilized to perform the procedure. For example, when performing a laparoscopic cholecystectomy to remove the gallbladder, a particular aspect of the procedure is the identification of the common bile duct.

"Similarly, when conducting procedures in the lower abdomen such as hernia repair or hysterectomies, great care should be taken to identify the ureter that connects the kidneys to the patient's bladder. Unfortunately, the ureter is at times obscured by connective tissue, and difficult to identify. These issues associated with identifying relatively small lumen (e.g. ureter, blood vessels, gall ducts, etc.) which at times are located proximal other similarly looking lumen are well known and systems have been devised to address them.

"For example, there are several systems which employ the use of a stent or catheter to be placed internal to the structure being identified. Some of these systems utilize a light generator which illuminates the lumen. The illumination can be in the visible spectrum for the doctor to easily recognize or in the infrared (IR) spectrum such that it can be detected using an IR camera. The light, in either event, is received by a camera and the doctor is able to visualize the location of the lumen in question.

"Another example of known devices employs a long stent placed into the ureter and extending from the bladder to the kidneys. Using a signal generator, the stent is electrified and produces an electrical field. The cutting or grasping surgical instrument used in the underlying surgical procedure includes one or more sensors which can detect the electrical field and signal an alarm if the cutting or grasping device comes too close to the lumen.

"These known systems have several significant drawbacks. The first is that they each require a specialized stent or catheter to be placed within and along the length of the lumen being detected. As a result, use of such devices requires a special surgeon to be employed in the mere placement of the stent or catheter. The placement in such delicate structures is quite difficult and time consuming. The use of an additional surgeon, one who likely is not otherwise involved in the underlying procedure being performed, significantly increases the cost of the procedure being performed. Further the placement is time consuming and thus increases the overall operating time for the patient. Again this increases the costs of the procedure, as well as increasing the time the patient must be sedated. With respect specifically to the detection of the ureter, placement of the stent or catheter can be quite problematic.

"Other known systems for detecting structures within the body employ the use of fluorescent dyes or other marker materials, such as radioactive fluids which can be used to detect the location of the desired structure within the body. Again there are shortcomings associated with these systems. The dyes employed often are not detectable through tissue, that is they cannot be easily detected from outside the lumen and are better employed in detecting cysts and polyps within a lumen as is common. Radioactive markers are also used to identify structures within a lumen using often x-ray and other visualization techniques. However, these visualization techniques are often not conveniently useable to identify structures while the surgical procedures described above are on-going.

"Yet a further known technique is the use of ultrasound imaging to provide clinicians the ability to image sub-surface structures. Ultrasound imaging relies on different acoustic impedances of adjacent tissue structures to provide the contrast required for imaging--usually without the addition of exogenous contrast agents, though these may be employed to identify particular structures. Current techniques include imaging prior to surgery with a trans-cutaneous probe or in the surgical field with a laparoscopic probe. Ultrasound imaging possesses several key advantages over other modes of imaging (e.g., CT, MRI, etc.) which make it very attractive for real-time application in surgery.

"The advantages of ultrasound imaging as compared to MRI and CT scans include the necessary hardware being relatively small and inexpensive. Further, the radiation levels imparted on the patient as well as clinicians is considered inherently safe which is not necessarily true for CT. Further, the data is collected instantly and at the point of use as opposed to requiring the patient be positioned in an imaging vessel.

"A variety of modes of operation for ultrasound imaging have been developed over the years include A-Mode, B-Mode, M-Mode and Doppler. A-mode (amplitude mode) is the simplest type of ultrasound. A single transducer scans a line through the body with the echoes plotted on screen as a function of depth. In B-mode (brightness mode) ultrasound, a linear array of transducers simultaneously or sequentially scans a plane through the body that can be viewed as a two-dimensional image on screen. In M-mode (motion mode) ultrasound, a single scan line is repeatedly sampled in the same location. The brightness representation of each scan in time is drawn vertically either from left to right on screen or in a fixed location on screen with the older results shifting to the left in a trailing update mode. Over time, this is analogous to recording a video in ultrasound. As the organ boundaries that produce reflections move relative to the probe, this can be used to determine the velocity of specific organ structures. Doppler mode makes use of the Doppler Effect in measuring and visualizing blood flow. In general, whether employing Color Doppler, Power Doppler, or Pulsed Wave Doppler, by calculating the frequency shift of a particular sample volume, for example flow in an artery or a jet of blood flow over a heart valve, the speed of the fluid and its direction can be determined and visualized. In for example, Pulsed Wave Doppler, velocity information is presented as a color coded overlay on top of a B-mode image. Other modes and combinations of modes are also employed in ultrasound imaging, as will be appreciated by those skilled in this art.

"There are however, disadvantages to current to ultrasound techniques, particularly the (laparoscopic approaches) which have limited its adoption in minimally invasive surgery. In some of these approaches the image is presented on a separate screen from the laparoscopic image, forcing the surgeon to mentally 'shift gears' as they focus on the laparoscope image or the ultrasound image. Current 2-D or even 3-D imaging systems generally seek to provide the highest level of image detail. While this may be useful in the diagnostic phase of care, this is likely more information than is necessary in the real-time treatment venue of an operating room where the questions facing the surgeon are not 'What's wrong?' but simply, 'Where is it?' Still further in many surgical suites, the required ultrasound cart and probes are simply not available as the need for sub-surface imaging does not exist in every surgical case.

"One drawback of current imaging systems is the size and cost of linear imaging arrays comprised of many small piezo electric elements. While they provide detailed images, these probes are costly to manufacture and bulky relative to the size of laparoscopic surgical devices. The present disclosure is directed to addressing these shortcomings of the current systems."

As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventors' summary information for this patent application: "To address the shortcomings of the current approach to ultrasound imaging, one aspect of the present disclosure is directed to a display with an integrated optical and ultrasound imaging. Further, according to another aspect the information presented to the surgeon is limited to just the most relevant information regarding subsurface structures rather than a full diagnostic image. Still a further aspect of the present disclosure is to integrate the ultrasound imaging transducer into one or more surgical instruments such that the need for a third instrument (and third hand) is eliminated. Additional aspects will also be described herein.

"In order to achieve one or more of the advances described above, one of the aspects of the present disclosure is directed to integration of a single ultrasound transducer into an existing laparoscopic device. A single ultrasound transducer can be effectively integrated at low cost, and is useful in paring down the volume of information provided to the surgeon. A single ultrasound transducer provides only a single vector of tissue data at any point in space and time.

"One aspect of the present disclosure is directed to a system including a laparoscopic surgical instrument having at least one ultrasound transducer, and a processor adapted to receive acoustic data from the ultrasound transducer and process the acoustic data from the ultrasound transducer to produce a graphical representation of the acoustic data. The graphical representation depicting echoic attributes of tissue substantially axially aligned with a transmission path of the at least one ultrasound transducer, and the distance of at least one tissue type having different echoic attributes from surrounding tissue form a distal tip of the laparoscopic surgical instrument.

"According to a further aspect of the present disclosure the graphical representation depicts the location of one or more lumens in axial alignment with the transmission path of the transducer. The graphical representation may depict a lumen with flowing blood or a fluid filled lumen. According to one aspect Doppler ultrasound is employed to identify the direction of flow in the one or more lumens.

"The processor may employ A-mode ultrasound, B-mode ultrasound, M-mode ultrasound, Color Doppler ultrasound, or Power Doppler ultrasound to generate the graphical representation.

"According to a further aspect of the present disclosure the system includes a tracking element, wherein the tracking element provides data to the processor enabling the processor to determine the location, speed, and direction data of the laparoscopic instrument. The tracking element may be selected from the group consisting of a robotic system, a strobe, a static fiducial element, a trackball affixed to the distal end of the laparoscopic instrument, and an optical motion sensor.

"According to a further aspect of the present disclosure, the system may include an optical imaging element outputting an optical image to a display. In certain aspects of the present disclosure the processor incorporates the location, speed and direction data received from the tracking element and outputs to the display a graphical overlay, the graphical overlay registering the movement of the laparoscopic surgical instrument and acoustic data from the ultrasound transducer on the optical image. The portion of the graphical overlay representing movement of the laparoscopic surgical instrument across the optical image may be shown in a first color and the portion of the graphical overlay representing a detected fluid filled lumen may be depicted in a second color.

"According to a further aspect of the present disclosure the display further comprises an ultrasound image depicting a cross-sectional view of tissue across which the laparoscopic instrument has been drawn. The ultrasound image may include a graphical overlay depicting one or more lumens. Further the processor may employ Doppler to identify the one or more lumens in the ultrasound image.

"A further aspect of the present disclosure is directed to a method including receiving ultrasound data from an ultrasound transducer, processing the ultrasound data to produce a graphical representation depicting echoic attributes of tissue substantially axially aligned with a transmission path of the ultrasound transducer and the distance of at least one tissue type having different echoic attributes from surrounding tissue from a distal tip of a laparoscopic instrument embodying the transducer, and outputting a signal for display of the graphical representation. The graphical representation may depict the location of one or more lumens in axial alignment with the transmission path of the transducer. The graphical representation may depict a lumen with flowing blood and/or a fluid filled lumen. Further, Doppler ultrasound may be employed to identify the direction of flow in the one or more lumens. Still further, the processing may employ A-mode ultrasound, C-mode ultrasound, M-mode ultrasound, Color Doppler ultrasound, or Power Doppler ultrasound.

"According to a further aspect of the present disclosure, the method includes tracking the laparoscopic instrument to determine its location, speed and direction. This may also include optically imaging a region of interest and outputting an optical image to a display. The method may further include processing the location, speed and direction of the laparoscopic instrument data and outputting to the display a graphical overlay, the graphical overlay registering the movement of the laparoscopic instrument and acoustic data from the ultrasound transducer on the optical image. The portion of the graphical overlay representing movement of the laparoscopic instrument across the optical image may be shown in a first color and the portion of the graphical display representing a detected fluid filled lumen is depicted in a second color.

"According to yet a further aspect of the present disclosure the method includes displaying an ultrasound image depicting a cross-sectional view of tissue across which the laparoscopic surgical instrument has been drawn. The ultrasound image may include a graphical overlay depicting one or more lumens. The method may further employ Doppler processing to identify one or more lumens in the ultrasound image. Still further, the method may include tracking of the laparoscopic surgical instrument to provide data enabling the determination of location, speed and direction data of the laparoscopic instrument. The ultrasound image may be registered with the location, speed, and direction data.

BRIEF DESCRIPTION OF THE DRAWINGS

"Various embodiments of the subject system and method are described herein with reference to the drawings wherein:

"FIG. 1 is a schematic illustration of a monopolar electrosurgical system in accordance with an illustrative embodiment of the present disclosure;

"FIG. 2 Fig. is a perspective view of a bipolar electrosurgical system in accordance with an illustrative embodiment of the present disclosure;

"FIG. 3 is a schematic block diagram of a generator in accordance with an illustrative embodiment of the present disclosure;

"FIG. 4A is a partial profile view of distal portions of an end effector of a surgical instrument according to an illustrative embodiment of the present disclosure;

"FIG. 4B is a partial profile view of distal portions of an end effector of a surgical instrument according to an illustrative embodiment of the present disclosure;

"FIG. 4C is a perspective view of a distal portion of an end effector of a surgical instrument according to an illustrative embodiment of the present disclosure;

"FIG. 4D are a profile view of an end effector of a surgical instrument according to an illustrative embodiment of the present disclosure;

"FIG. 5 is a perspective view of an ultrasound probe according to a further illustrative embodiment of the present disclosure;

"FIG. 6 is an exploded view of an ultrasound transducer according to one illustrative embodiment of the present disclosure;

"FIG. 7A depicts an ultrasound material and method of forming hexagonal transducer according to an illustrative embodiments of the present disclosure;

"FIG. 7B depicts an alternative ultrasound transducer arrangements according to an illustrative embodiments of the present disclosure;

"FIG. 8 is a perspective view of an electrosurgical instrument interrogating tissue according to one illustrative embodiment of the present disclosure;

"FIG. 9 is an image of an echo response from an ultrasound interrogation signal;

"FIG. 10 is a schematic block diagram of an ultrasound system according to one illustrative embodiment of the present disclosure;

"FIG. 11A is a schematic of a two alternative driver circuit arrangements according to two illustrative embodiments of the present disclosure;

"FIG. 11B is a schematic of a further driver circuit arrangement according to one illustrative embodiment of the present disclosure;

"FIG. 12 is a schematic of a feedback loop for gain control according to one illustrative embodiment of the present disclosure;

"FIG. 13 is a composite optical image and 'visual ruler' according to one illustrative embodiment of the present disclosure;

"FIG. 14 is a schematic of three different image display arrangements according to illustrative embodiments of the present disclosure;

"FIG. 15 is a schematic of an electrosurgical instrument with ultrasound probe interrogating tissue according to one illustrative embodiment of the present disclosure;

"FIG. 16 is an ultrasound image based on the interrogation of FIG. 14 according to the present disclosure;

"FIG. 17 is a flow chart of the image processing to produce a Doppler ultrasound image according to one illustrative embodiment of the present disclosure;

"FIG. 18 is a flow chart of the alternative processing to produce a Doppler ultrasound image according to one illustrative embodiment of the present disclosure;

"FIG. 19A is a profile view of a distal portion of a surgical instrument employing a track ball to determine speed and direction according to one illustrative embodiment of the present disclosure;

"FIG. 19B is a profile view of a surgical instrument employing an optical motion sensor to determine speed and direction according to one illustrative embodiment of the present disclosure;

"FIG. 20A is an optical display of a surgical instrument employing an active tracking device according to one illustrative embodiment of the present disclosure;

"FIG. 20B is a graphical display of a surgical instrument employing an active tracking device according to one illustrative embodiment of the present disclosure;

"FIG. 21 is a perspective view of a robotic manipulator system according to one illustrative embodiment of the present disclosure;

"FIG. 22 is a representative display of a bladder and ureter according to one illustrative embodiment of the present disclosure;"

For additional information on this patent application, see: ZHENG, PENG; VALENTINE, CHRISTOPHER A.; RUSIN, CHRISTOPHER T.; ROOKS, KATHY E.; CORUM, BENJAMIN M.; JANDRALL, SALLY D.; JOHNSON, KRISTIN D. System and Method for Detecting Critical Structures Using Ultrasound. Filed March 15, 2013 and posted January 23, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=1479&p=30&f=G&l=50&d=PG01&S1=20140116.PD.&OS=PD/20140116&RS=PD/20140116

Keywords for this news article include: Robotics, Machine Learning, Emerging Technologies.

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Source: Politics & Government Week


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