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EP-3946126-B1 - SYSTEM FOR PREDICTING CURRENT PATHS AND EVALUATING ELECTRICAL BURN RISKS OF A MONOPOLAR ELECTROSURGERY TOOL

EP3946126B1EP 3946126 B1EP3946126 B1EP 3946126B1EP-3946126-B1

Inventors

  • VENKATARAMAN, JAGADISH

Dates

Publication Date
20260506
Application Date
20191108

Claims (13)

  1. A non-transitory computer readable storage medium for predicting potential current paths within a patient's body when using a monopolar electrosurgery tool on the patient, the computer readable storage medium comprising instructions which, when executed by one or more processors, cause the one or more processors to: receive locations of an active electrode and a return electrode of the monopolar electrosurgery tool on the patient's body; identify a set of tissues between the locations of the active electrode and the return electrode; augment each of the set of identified tissues with a corresponding value of an electrical property; use a current path model, the set of identified tissues, and the set of corresponding values of the electrical property to predict a set of potential current paths between the active electrode and the return electrode, wherein the set of predicted current paths is a first set of predicted current paths and wherein the locations of the active electrode and the return electrode are initial locations; determine if any of the first set of predicted current paths can cause potential tissue burn injuries due to the predicted current path flows through a metal implant and/or due to the predicted current path flows through a part of the patient's body touching a grounded metal object; and if so, send a first warning message to a surgical staff and highlight one or more locations of the potential tissue burn injuries on the one or more identified current paths among the first set of predicted current paths on a display.
  2. A system (400) for predicting potential current paths within a patient's body when using a monopolar electrosurgery tool on the patient, comprising: one or more processors (412); a memory (404, 410) coupled to the one or more processors; and wherein the one or more processors are configured to: receive locations of an active electrode and a return electrode of the monopolar electrosurgery tool on the patient's body; identify a set of tissues between the locations of the active electrode and the return electrode; augment each of the set of identified tissues with a corresponding value of an electrical property; predict a set of potential current paths between the active electrode and the return electrode and potential tissue burn associated with each of the set of potential current paths based on a current path model, the set of identified tissues, and the set of corresponding values of the electrical property, wherein the set of predicted current paths is a first set of predicted current paths and wherein the locations of the active electrode and the return electrode are initial locations; determine if any of the first set of predicted current paths can cause potential tissue burn injuries due to the predicted current path flows through a metal implant and/or due to the predicted current path flows through a part of the patient's body touching a grounded metal object; and if so, send a first warning message to a surgical staff and highlight one or more locations of the potential tissue burn injuries on the one or more identified current paths among the first set of predicted current paths on a display.
  3. The non-transitory computer readable storage medium of claim 1 or the system (400) of claim 2, wherein identifying the set of tissues between the locations of the active electrode and the return electrode includes: Receiving a three-dimensional, 3D, scan of the patient's body; segmenting anatomical structures between the locations of the active electrode and the return electrode based on the received 3D scan; and identifying the set of tissues from the segmented anatomical structures.
  4. The non-transitory computer readable storage medium of claim 3 or the system (400) of claim 3, wherein identifying the set of tissues between the locations of the active electrode and the return electrode includes; receiving an endoscope video which captures anatomical structures inside the patient's body along the way between the active electrode and the return electrode; and segmenting the captured anatomical structures to identify the set of tissues.
  5. The non-transitory computer readable storage medium of claim 3 or the system (400) of claim 3, wherein identifying the set of tissues from the segmented anatomical structures further includes identifying a set of dimensions for each of the set of identified tissues.
  6. The non-transitory computer readable storage medium of claim 3, wherein the computer-readable storage medium further comprises instructions which, when executed by the one or more processors, cause the one or more processors to: extract from the 3D scan, locations and dimensions of one or more metal implants inside the patient's body; and provide the extracted locations and dimensions of the one or more metal implants to the current path model as inputs for predicting the set of potential current paths.
  7. The system (400) of claim 3, wherein the one or more processors (412) are further configured to: extract from the 3D scan, locations and dimensions of one or more metal implants inside the patient's body; and provide the extracted locations and dimensions of the one or more metal implants to the current path model as inputs for predicting the set of potential current paths.
  8. The non-transitory computer readable storage medium of claim 1 or the system (400) of claim 2, wherein the electrical property is a dielectric property, and wherein augmenting each of the set of identified tissues with a corresponding value of the electrical property includes using a look-up table containing estimated dielectric constants of various types of tissues within a human body.
  9. The non-transitory computer readable storage medium of claim 1 or the system (400) of claim 2, wherein augmenting each of the set of identified tissues with a corresponding value of the electrical property further includes: extracting color information for an identified tissue in the set of identified tissues from endoscope video images of anatomical structures inside the patient's body along the way between the active electrode and the return electrode; converting the color information into a modifier to modify a corresponding dielectric constant value associated with the identified tissues from the look-up table; and augmenting the identified tissue with the modified dielectric constant value.
  10. The non-transitory computer readable storage medium of claim 1 or the system (400) of claim 2, wherein predicting the set of potential current paths from the active electrode to the return electrode further includes computing a probability value for each of the set of potential current paths, wherein a potential current path in the set of potential current paths having a lower overall resistance is associated with a higher probability value.
  11. The non-transitory computer readable storage medium of claim 10, wherein the computer-readable storage medium further comprises instructions which, when executed by the one or more processors, cause the one or more processors to: display one or more potential current paths in the set of potential current paths which have the highest probability values; and for each of the displayed potential current paths, highlight one or more locations of potential tissue burn injuries due to the potential current path flows through a metal implant and/or the potential current path flows through a part of the patient's body touching a grounded metal object.
  12. The system (400) of claim 10, wherein the system further includes a display device, and wherein the one or more processors (412) are further configured to: display on the display device one or more potential current paths in the set of potential current paths which have the highest probability values; and for each of the displayed potential current paths, highlight one or more locations of potential tissue burn injuries due to the potential current path flows through a metal implant and/or the potential current path flows through a part of the patient's body touching a grounded metal object.
  13. The non-transitory computer readable storage medium of claim 1, wherein after sending the first warning message, the computer readable storage medium further comprises instructions which, when executed by one or more processors, cause the one or more processors to: receive a new location of the return electrode of the monopolar electrosurgery tool on the patient's body; use the current path model to generate a second set of predicted current paths inside the patient's body between the new location of the return electrode and the initial location of the active electrode; determine if any of the second set of predicted current paths can still cause potential tissue burn injuries due to the predicted current path flows through a metal implant and/or due to the predicted current path flows through a part of the patient's body touching a grounded metal object; and if so, send a second warning message to the surgical staff and highlight one or more locations of the potential tissue burn injuries on the one or more identified current paths among the second set of predicted current paths on the display.

Description

TECHNICAL FIELD The present disclosure generally relates to monopolar electrosurgery and, more specifically, to systems, devices and techniques for predicting potential current paths from an active electrode of a monopolar electrosurgery tool to a return electrode of the monopolar electrosurgery tool, and evaluating and eliminating tissue burn risks associated with the predicted current paths. BACKGROUND Generally speaking, there are two main types of electrosurgery tools: bipolar electrosurgery tools and monopolar electrosurgery tools. A bipolar electrosurgery tool typically includes a pair of forceps-like electrodes: the electrical current flows from one tip of the forceps-like tool (i.e., the first electrode) to the other tip of the forceps-like tool (i.e., the second electrode) through the target tissue between the two tips, so that the current does not actually go into a patient's body. In contrast, in a monopolar electrosurgery tool, an active electrode of the monopolar electrosurgery tool is placed at the surgical site of a patient. A return electrode of the monopolar electrosurgery tool (also known as the "dispersive pad" or the "grounding pad") is placed somewhere else on the patient's body, which is often on the opposite side of the patient's body to where the surgical site and the active electrode are located. Hence, the main electrical current of the monopolar electrosurgery tool flows from the active electrode to the return electrode/grounding pad through the patient's body following a path of least resistance as it completes a full circuit. While bipolar electrosurgery tools are still being used in some electrosurgery procedures, it can be quite difficult to find enough space to place both electrodes around a small surgical site. In contrast, a monopolar electrosurgery tool, which only uses the active electrode at the surgical site, can be much easier to place and convenient to work with. However, because the patient's body is used as a part of the current return path in monopolar electrosurgery, cares must be taken to prevent accidental tissue burns inside the patient's body, especially when there are metal objects, such as metal implants inside the patient's body. Paolo Bifulco et al. "Investigation the role of capacitive coupling between the operating table and the return electrode of an electrosurgery unit in the modification of the current density distribution within the patients' body" discusses the role played from capacitive coupling between the return electrode and the conductive operating table in the current density in a patient's body. SUMMARY The invention is defined by the features of the independent claims. Preferred embodiments are given in the dependent claims. This patent disclosure provides various embodiments of predicting potential current pad of the monopolar electrosurgery tool based on analyzing electrical properties of tissues inside a patient's body, and evaluating and eliminating tissue burn risks associated with the predicted current paths. In some embodiments, a disclosed current-path-prediction technique is designed to predict a set of potential current paths from the active electrode to the grounding pad for any given geometrical configuration of the two electrodes on the patient's body. These predicted current paths can then be pictorially displayed on a three-dimensional (3D) scan of the patient's body or an endoscopic view of the patient's body and in relation to the display of any existing metal implant inside the patient's body, thereby allowing for visualizing points of tissue burn risks inside the patient's body. For example, when a predicted current path intersects the location of a metal implant inside the patient's body, a potential tissue burn risk is identified and the location where the current path meets the metal implant can be highlighted. Based on the display of the predicted current paths and highlighted locations of tissue burn risks, surgical staff can choose to reposition the grounding pad of the monopolar electrosurgery tool to alter the potential current paths. The disclosed current-path-prediction technique can then be applied to the new electrodes configuration to generate another set of potential current paths from the active electrode to the new grounding pad location. Next, the potential tissue burn risks can be reevaluated for the new set of potential current paths inside the patient's body. If one or more tissue burn risks are identified for the new set of potential current paths, the grounding pad can be reposition again, and this current prediction-evaluation procedure can be repeated. Moreover, the predicted current paths can also reveal any accidental contact of a part of the patient body with a grounded metal object, such as the surgery table or a metal tray table. Such a body/metal contact can cause a current to bypass the grounding pad and flow to the body/metal contact location, causing accidental tissue burns. Hence, based o