The present invention generally relates to a detection of a foreign object in proximity of a surgical end-effector within an anatomical region. The present invention specifically relates to the use of one or more optic fiber “feeler(s)” relative to a surgical end-effector for detecting the foreign object in proximity of a surgical end-effector within an anatomical region.
Penetration of a foreign object in tissue is a common injury during both civilian accidents and military warfare. The most critical injury is a penetrating heart injury. This type of injury may occur because of a direct penetrating injury through the chest and the pericardium or because of embolization of foreign bodies from the venous vasculature. In symptomatic cases, the foreign object in contact with blood flow must be extracted in order to avoid life threatening conditions, such as, for example, embolization of shrapnel into the pulmonary artery or other key vascular beds (e.g., a cerebral circulation via the carotids arteries) that potentially causes vessel rupture or embolization of thrombi which form on the foreign object in contact with blood flow, which in turn potentially causes ischemia and infarction.
One method known in the art for detecting a foreign object is to induce vibrations of ferromagnetic shrapnel to detect the shrapnel with three-dimensional (“3D”) Doppler Ultrasound images. The detected position is used to guide a robotic system to capture the foreign object. However, ultrasonic tracking of the foreign object may provide localization to a level of accuracy limited by the resolution of ultrasound images and the quality of signal footprint associated with the foreign object (i.e., signal-to-noise ratio/carrier-to-noise ratio). This accuracy might be sufficient to guide the robot towards the foreign object. However, once the surgical end-effector of the robot is in close proximity to the targeted foreign object (e.g., <10 mm), a better accuracy is required if the robot system is to deploy a foreign object catching mechanism. In addition, this method works only with ferrous shrapnel.
The present invention provides an optical fiber detection tool for sensing the presence of a foreign object when the foreign object is in close proximity to a surgical end-effector of a surgical robotic system. In contrast to imaging based guidance which may lead a manipulator at a macro-level to the general location of the foreign object, this optical fiber detection tool of the present invention allows for fine-tuned manipulation of the surgical end-effector when the surgical end-effector is in the close vicinity of the foreign object itself. This behavior is enabled by a plurality of optical fiber “feelers” having a defined spatial relationship with the surgical end-effector. These feelers are optically-interrogated to allow for high-sensitivity characterization of feeler deflection/shape and this information may be coupled back to the interventionalist as a visual display and/or audio warning to help in steering of the instrument. This information may also be fed back within a closed feedback control loop for robotic manipulator guidance in a fully automated fashion.
The optical fiber detection tool of the present invention may involve a deflection analysis or a shape reconstruction of an optical fiber by encoding geometric changes into light transmitted into the optical fiber. Specifically, deflection analysis/shape reconstruction of an optical fiber may be performed by making use of variations in an optical refractive index that occur due to introduction of fiber Bragg gratings in the optical fiber or due to natural inhomogeneities in optical refraction arising from the manufacturing process of the optical fiber. A fiber Bragg grating is a short segment of optical fiber that reflects particular wavelengths of light and transmits all others. This is achieved by adding a periodic variation of the refractive index in the fiber core, which generates a wavelength-specific dielectric mirror. A fiber Bragg grating is sensitive to strain, which causes a shift in the Bragg wavelength ΔλB of the fiber Bragg grating in proportion to the magnitude of strain. A primary advantage of using fiber Bragg gratings for distributed sensing is that a large number of deformation optic sensors may be interrogated along a length of a single optical fiber. In similar fashion, fiber deformation may be sensed using a Rayleigh scattering approach that exploits the natural variation in optical refractive index occurring along a length of an optical fiber.
One form of the present invention is an optical detection tool employing a surgical end-effector (e.g., an endoscope, a catheter, etc.) and an optical fiber (e.g., single core or multi-core). In operation, the surgical end-effector is navigated within an anatomical region relative to an object foreign to the anatomical region and the optical fiber generates an encoded optical signal indicative of a strain measurement profile of the optical fiber as the surgical end-effector is navigated within the anatomical region. The optical fiber has a detection segment in a defined spatial relationship with the surgical end-effector, wherein strain measurement profile represents a normal profile in the absence of any measurable contact of the foreign object with the detection segment of the optical fiber and conversely, wherein the strain measurement profile represents an abnormal profile in response to a measurable contact of the foreign object with the detection segment of the optical fiber.
A second form of the present invention is an optical fiber detection method involving a navigation of a surgical end-effector within an anatomical region relative to an object foreign to the anatomical region and a generation of an encoded optical signal indicative of a strain measurement profile of an optical fiber as the surgical end-effector is navigated within the anatomical region. The optical fiber has a detection segment in a defined spatial relationship with the surgical end-effector, wherein the strain measurement profile represents a normal profile in the absence of any measurable contact of the foreign object with the detection segment of the optical fiber and conversely, wherein the strain measurement profile represents an abnormal profile in response to a measurable contact of the foreign object with the detection segment of the optical fiber.
The foregoing forms and other forms of the present invention as well as various features and advantages of the present invention will become further apparent from the following detailed description of various exemplary embodiments of the present invention read in conjunction with the accompanying drawings. The detailed description and drawings are merely illustrative of the present invention rather than limiting, the scope of the present invention being defined by the appended claims and equivalents thereof.
As shown in
For purposes of the present invention, an optical fiber 20 is broadly defined herein as any article or device structurally configured for transmitting/reflecting light by means of successive internal optical reflections via a deformation optic sensor array with each deformation optic sensor of the array being broadly defined herein as any article structurally configured for reflecting a particular wavelength of light while transmitting all other wavelengths of light whereby the reflection wavelength may be shifted as a function of an external stimulus applied to optical fiber 20. Examples of optical fiber 20 include, but are not limited to, a flexible optically transparent glass or plastic fiber incorporating an array of fiber Bragg gratings integrated along a length of the fiber as known in the art, and a flexible optically transparent glass or plastic fiber having naturally variations in its optic refractive index occurring along a length of the fiber as known in the art (e.g., a Rayleigh scattering based optical fiber). In practice, each optical fiber 20 may include one or more fiber cores as known in the art.
Also for purposes of the present invention, surgical end-effector 30 is broadly defined herein as any article or device structurally configured for implementing a surgical procedure within an anatomical region as controlled by a surgical robotic system as known in the art. Examples of surgical end-effector 30 include, but are not limited to, an endoscope, a catheter, a cannula, a balloon, a filter, a stent or any other surgical tool known in the art that may serve as an end-effector of a surgical robotic system.
In practice, an optical fiber 20 generates an encoded optical signal in the form of a reflection spectrum as known in the art that indicates strain measurements along the length of optical fiber 20. As will be explained in more detail in connection with
The present invention is premised on incorporating optical fiber 20 with surgical end-effector 30 in a manner that provides a known spatial relationship between a foreign object detection segment of optical fiber 20 and surgical end-effector 30. For purposes of the present invention, the term “foreign object” is broadly defined herein as any object within an anatomical region not deemed to be a conventional object within the anatomical region or designated for removal from the anatomical region, conventional or not. For example, within a chest region, conventional objects include cardiac organs/tissue, and foreign objects may include any type of non-cardiac objects, metallic or non-metallic (e.g., shrapnel).
In one exemplary embodiment of an optical fiber tool as shown in
In practice, tubular end-effector 31 may include an inner tube as shown for supporting optical fibers 22 and an outer tube (not shown) that may be translated in a distal direction for covering a segment or an entirety of foreign object detection segments 22b as desired.
In another embodiment of an optical fiber tool as shown in
In practice, tubular end-effector 31 may include an inner tube as shown for supporting optical fibers 24 an outer tube (not shown) that may be translated in a distal direction for covering a segment or an entirety of foreign object detection segments 24b as desired.
In yet another embodiment of an optical fiber tool as shown in
In practice, tubular end-effector 32 may include an inner tube as shown for supporting optical fibers 25 and 26 and an outer tube (not shown) that may be translated in a distal direction for covering a segment or an entirety of foreign object detection segments 25b and 26b as desired.
Referring to back to
A description of a surgical system will now be described herein to facilitate an understanding of an operational use of an optical fiber detection tool of the present invention.
As shown in
Imaging system 60 is broadly defined herein as any type of imaging system structurally configured for imaging an anatomical region 51 of a patient 50. Examples of imaging system 60 known in the art include, but are not limited to, an X-ray system, a MRI system, a CT system, an US system or an IVUS system.
Robot manipulator 70 is broadly defined herein as any type of robotic device structurally configured with motorized control of one or more joints for navigating a surgical end-effector within an anatomical region as desired for the particular surgical procedure, such as, for example, a controlled maneuvering of surgical end-effector 31 within anatomical region 50 for retrieving a foreign object 52 as shown. In practice, robot manipulator 61 may have four (4) degrees-of-freedom, such as, for example, a serial robot having joints serially connected with rigid segments, a parallel robot having joints and rigid segments mounted in parallel order (e.g., a Stewart platform known in the art) or any hybrid combination of serial and parallel kinematics. In addition, as shown, an endoscopic device 71 may be integrated with surgical end-effector 31 and robotic manipulator 70 for providing a localized visualization of anatomical region 51 as known in the art.
Robot controller 72 is broadly defined herein as any controller structurally configured for providing robot actuator commands to robot manipulator 70 for navigating surgical end-effector 31 as desired for the surgical procedure, such as, for example, navigating surgical end-effector 31 for retrieving foreign object 52 within anatomical region 50 as shown. To this end, robot controller 72 employs an imaging navigation module 73 for navigating surgical end-effector 31 within an anatomical region 51 either manually or automatically via images generated by imaging system 60 as known in the art and a detection navigation module 62 for navigating surgical end-effector 31 within anatomical region 51 either manually or automatically via foreign objection detection information received from optical interrogation console 80 as will be further explained herein in connection with
Optical interrogation console 80 is broadly defined herein as any console structurally configured for transmitting light through the optical fibers 22 for processing encoded optical signals generated by the successive internal reflections of the transmitted light via the deformation optic sensor array of each optical fiber 22. In one embodiment, optical interrogation console 80 employs an arrangement (not shown) of a coherent optical source, photodetectors, a frequency domain reflectometer and other appropriate electronics/devices as known in the art. For this embodiment, light from the coherent optical source is split between reference optic fiber (not shown) external to surgical end-effector 31 and optical fibers 22 as is typical for optical frequency domain reflectometry. The light for optical fiber 22 is further split using beam splitters to simultaneously illuminate the plurality of optical fibers 22. The frequency domain reflectometer interrogates backscattered light reflected from optical fibers 22 and coherently mixing these reflections with light returning from the reference optic fiber.
For all embodiments, optical interrogation console 80 employs a detection module 81 structurally configured for executing a deflection analysis and/or shape reconstruction of optical fibers 22 directed to localizing the detection segments 22b based on the encoded optical signals in form of digitized interferometric signals. In one embodiment, detection module 81 consists of software, firmware and/or hardware for implementing stages S92 and S93 of flowchart 90 as shown in
Referring to
Stages S92 and S93 operate in a loop for facilitating a micro-navigation of surgical end-effector 31 within anatomical region until such time optic fibers 22 detect the presence of foreign object 52 whereby responsive action(s) to the detection of the foreign object 52 are executed during a stage S94 of flowchart 90 (e.g., a removal of foreign object 52 or an avoidance of foreign object 52 as surgical end-effector 31 is further navigated within anatomical region 51). In general, the significant difference between the macro-navigation of stage S91 and the micro-navigation loop of stages S92-S93 is the execution of a strain measurement profile analysis method of the present invention as represented by a flowchart 100 shown in
Referring to
In one embodiment of stages S102 and S103, as shown in
The deflection profile is continually updated and one or more of the deflection profiles transition to an abnormal profile upon an exertion of a measurable contact of foreign object 52 with one or more of the foreign object detection segments 22a of optical fibers 22, such as, for example, an abnormal frequency profile 112 shown in
In practice, those having ordinary skill in the art will appreciate the degree of shift in nominal frequencies of optical fibers 22 to establish the transition from a normal frequency profile to an abnormal frequency profile is dependent upon a required measurable contact sensitivity of optical fibers 22 to foreign object 52 as opposed to any conventional objects within anatomical region 51 or a required measurable contact sensitivity of optical fibers 22 to any conventional object(s) designated for removal from anatomical region 51.
In an alternative embodiment of stages S102 and S103 using optical fibers 24 (
The shape reconstruction profile is continually updated and one or more of the shape reconstruction profiles transition to an abnormal profile upon an exertion of a measurable contact of foreign object 52 with one or more of the foreign object detection segments 24a of optical fibers 24, such as, for example, an abnormal profile 122 shown in
In practice, those having ordinary skill in the art will appreciate the degree of distortion in the pre-designed geometric shape of the foreign object detection segments 24a of optical fibers 24 to establish the transition from a normal profile to an abnormal profile is dependent upon a required measurable contact sensitivity of optical fibers 24 to foreign object 52 as opposed to any conventional objects within anatomical region 51 or a required measurable contact sensitivity of optical fibers 24 to conventional objects designated for removal from anatomical region 51.
Referring back to
From the description of
Those having ordinary skill in the art will further appreciate that, in practice, the exact definitions of a foreign body, a measurable contact sensitivity of foreign object detection segments of the optical fibers, a normal strain measurement profile and an abnormal strain measurement profile are dependent upon how a particular surgical procedure is utilizing a optical fiber detection tool of the present invention.
While various exemplary embodiments of the present invention have been illustrated and described, it will be understood by those skilled in the art that the exemplary embodiments of the present invention as described herein are illustrative, and various changes and modifications may be made and equivalents may be substituted for elements thereof without departing from the true scope of the present invention. For example, although the invention is discussed herein with regard to FBGs, it is understood to include fiber optics for shape sensing or localization generally, including, for example, with or without the presence of FBGs or other optics, sensing or localization from detection of variation in one or more sections in a fiber using back scattering, optical fiber force sensing, fiber location sensors or Rayleigh scattering. In addition, many modifications may be made to adapt the teachings of the present invention without departing from its central scope. Therefore, it is intended that the present invention not be limited to the particular embodiments disclosed as the best mode contemplated for carrying out the present invention, but that the present invention includes all embodiments falling within the scope of the appended claims.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/IB2012/050338 | 1/25/2012 | WO | 00 | 7/11/2013 |
Number | Date | Country | |
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61437314 | Jan 2011 | US |