Abstract:
An access port or retractor tube provides access through tissue to a surgical site or field, such as at the brain or spine, in a minimally invasive manner. The access port permits a user to clearly view and access the surgical field, including areas medial thereto, in a minimally invasive manner by dilating or separating tissue rather than cutting tissue. Neuro monitoring and neuro navigation are tools essential to neuro surgery to protect vital and eloquent tissues. Combining navigation and monitoring into the access ports/retractor tubes would enable the surgeon to be more precise and efficient during minimally invasive procedures while still being maximally effective in protecting non operative tissues.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority from U.S. Provisional Application No. 62/028,023 filed Jul. 23, 2014 the disclosure of which is incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention(s) relate to neuro surgery equipment, and more particularly, to access ports, retractor tubes, locator rods and sensors for neuro monitoring and neuro navigation. The present invention(s) relate to methods and devices for minimally invasive brain and spine surgery and devices for performing said surgeries. More specifically, the current invention(s) are modifications to existing minimally invasive access retractor ports and locator/dilating tubes with integration of neuro navigation/neuro monitoring. 
       BACKGROUND ART 
       [0003]    In the field of neuro surgery, including brain and spine surgery, it is extremely important to be able to monitor the integrity of neural tissue during surgery. Neuro monitoring is a procedure in which the electrical conductivity of peripheral nerves and control centers in the brain are monitored with real time feedback given to the surgeon while operating, to allow him/her to know if there has been any compromise to eloquent tissues that control motor and or sensory function, thereby reducing risk of adverse events such as paralysis, pain or numbness. 
         [0004]    Neurosurgeons routinely use neuro navigation during surgery as well. Navigation is a computer system that integrates pre-operative scans such as CT or MRI with the patient&#39;s actual anatomy in the operating room, allowing the surgeon to know where he/she is in the brain or spinal cord. This enables the surgeon to steer clear of very sensitive nervous system tissues, while performing any number of required procedures, such as brain/spine tumor resections, aneurysm clippings and pedicle screw placement during spinal fusions. This technology has had advancements in the last several years, combining the scan images into the operating microscope, reducing the surgeons&#39; time of coming out of the operative field to reassess the exact location of the anatomy in question. 
       DISCLOSURE 
     Technical Problem 
       [0005]    Over the last decade, an effort has been made in the field of surgery to perform operations in a minimally invasive setting. Medical literature shows that with minimally invasive approaches, the patient&#39;s recovery is faster and hospitalization is shorter. With minimally invasive surgery, techniques and tools have been developed to reduce trauma to non-essential tissue; however, increasing the final diameter of these tools may cause undesired damage to a patient&#39;s tissue. 
       Solution to Problem 
       [0006]    In accordance with an aspect of the present invention(s), there are several design modifications to access retractor ports, as well as the tools for placing said ports into the patient such as incorporation of a gasket. The inventions are also intended to combine neuro navigation and neuro monitoring into the retractor ports and locator rods thereby increasing the ability to perform minimally invasive surgeries safely, in areas of the brain and spine, that have been reserved to painful and time consuming “open” or “standard” procedures. According to non-limiting exemplary embodiments, it is also intended that the design modifications to the current retractor ports are to eliminate the use of dilating tubes, reducing the chance of prolapse and herniation of delicate human tissue into open space between said dilating tubes. Exemplary embodiments of the herein described access retractor ports are configured to accommodate ultrasound aspirators for use in and around vital structures of a body as described by PCT application PCT/US2015/027531. 
       Advantageous Effects of Invention 
       [0007]    The current invention is designed to modify and incorporate several of the common tools used in neurosurgery. Modifications to access equipment are vital to assure the safety and integrity of anatomy that is not essential to the surgery being performed. Combining navigation and monitoring technologies into the retractor systems will enable the surgeon to have continuous feedback of his/her location in the brain or spinal cord while actively performing the activities of surgery. By reducing the need to frequently change visual fields from microscope to computer screen, this will increase the operators&#39; ability to perform said surgeries more efficiently. Further, the gasket reduces open spaces and improves preservation of tissues at least at distal ends of retractor tubes, dilating tubes and a locator rod. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  illustrates a retractor tube and gasket according to embodiments of the present invention. 
           [0009]      FIG. 2  illustrates a series of dilating tubes having respective gasket fixation grooves according to embodiments of the present invention. 
           [0010]      FIG. 3  illustrates a locator rod according to embodiments of the present invention. 
           [0011]      FIG. 4 a    illustrates a top-down view of a retractor tube with integrated sensors according to embodiments of the present invention. 
           [0012]      FIG. 4 b    illustrates a side-view of a retractor tube with integrated sensors according to embodiments of the present invention. 
           [0013]      FIG. 5 a    illustrates a top-down view of an expandable retractor tube surrounded by an expandable sleeve. 
           [0014]      FIG. 5 b    illustrates a side-view of an expandable retractor tube surrounded by an expandable sleeve. 
           [0015]      FIG. 6  illustrates a flowchart of placing a retractor tube into a tissue. 
           [0016]      FIG. 7  illustrates a flowchart of placing an expandable surgical retractor into a tissue. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0017]    The advantages, features and aspects of the invention will become apparent from the following description of the embodiments with reference to the accompanying drawings, which is set forth hereinafter. Therefore, those skilled in the field of this art of the present invention can embody the technological concept and scope of the invention easily. In addition, if it is considered that detailed description on a related art may obscure the points of the present invention, the detailed description will not be provided herein. The specific embodiments of the present invention will be described in detail hereinafter with reference to the attached drawings. 
         [0018]      FIG. 1  illustrates a minimally invasive surgery (MIS) retractor tube with navigation fixation point and protective gasket  1000 . The MIS retractor tube with navigation fixation point and protective gasket  1000  includes a retractor tube  100  and a gasket  200 . Although gaskets are discussed herein, the gaskets may be interchanged with boots or expandable sleeves, as discussed further below. 
         [0019]    The retractor tube  100  has a fixed length  101 , navigation fixation point  110 , and gasket fixation groove  210 . The retractor tube  100  is configured to be inserted into a patient to provide a view through an interior of the tube to a patient tissue, such as neural and/or surrounding tissues. 
         [0020]    The retractor tube  100  may be composed of brain tissue compatible materials, such as stainless steel and/or titanium. 
         [0021]    A proximal end of the retractor tube  100  includes a base plate  170  which may or may not be configured to attach to a patient&#39;s bone or other fixing structure to hold the retractor tube  100  in place, as will be described further in reference to the retractor fixation point  130   a  and retractor fixation point  130   b  of  FIG. 4 a   . The retractor tube  100  also includes a navigation fixation point  110  to which a locator rod  400  may be attached as described further in reference to  FIG. 3 . 
         [0022]    The retractor tube  100  is configured such that the gasket fixation groove  210  provide fixation points for a gasket  200  to be attached to a distal end  120  of the retractor tube  100 . The gasket  200  provides increased friction and cushioning to a patient tissue, as opposed to a base retractor tube  100 , and thereby prevents prolapse and herniation of tissue into the retractor tube  100  and/or unnecessary damage to the tissue. The gasket acts as a boot, sitting at an opening of the retractor tube  100 . 
         [0023]    The gasket  200  is configured to fit to the distal end  120  of the retractor tube  100  and to connect with the gasket fixation groove  210  thereof. According to exemplary embodiments, the gasket  200  fits to the distal end  120  according to any of elastic restoration of the gasket, mechanical interaction with the gasket fixation groove  210  and adhesive properties; however, this is merely exemplary and other equivalent means of fitting the gasket  200  to the retractor tube  100  may be employed. 
         [0024]    The gasket  200  may be composes of any of silicone, latex, rubber and other soft, non-allergenic materials. 
         [0025]      FIG. 2  illustrates MIS dilating tubes with gasket and gasket fixation grooves  2000 . The MIS dilating tubes with gasket and gasket fixation grooves  2000  includes a sequence of dilating tubes  301 - 305 . 
         [0026]    The dilating tubes  301 - 305  are configured to be inserted into a patient to provide a sequence of expanding views to a patient tissue, such as neural and/or surrounding tissues. According to an example embodiment, diameters of the dilating tubes  301 - 305  increase from dilating tube  301  to dilating tube  305 , and the dilating tube  301  is first inserted into a patient, and then either dilating tube  302  is inserted concentrically about dilating tube  301 , or dilating tube  301  is removed and inserted into a different location. This process continues until dilating tube  305  is concentric about dilating tube  304  and or any of dilating tubes  301 - 303 . The retractor tube  100  of  FIG. 1  may then be inserted into the patient concentrically about dilating tube  305 , as retractor tube  100  has a diameter greater than dilating tube  305 . 
         [0027]    As illustrated by  FIG. 2 , each of the dilating tubes  301 - 305  respectively has one of the gasket fixation grooves  311 - 315  at a distal end  120  thereof such that one of the gaskets  321 - 325  may be fixed thereupon as similarly described for the gasket  200  of  FIG. 1 . Each of the gasket fixation grooves  311 - 315  and gaskets  321 - 325  may have respective diameters so that the gaskets  321 - 325  may be fit to respective dilating tubes  301 - 305 . The dilating tubes  301 - 305  create a channel for a dilating iris cylinder to be placed with gradual retraction of the patient&#39;s tissue and may have beveled edges. 
         [0028]      FIG. 3  illustrates an MIS locator rod with gasket and gasket fixation grooves  3000 . The MIS locator rod with gasket and gasket fixation grooves  3000  includes a locator rod  400 . The locator rod  400  includes a sensor fixation arm  420 , fixed length increment lines  430 , and gasket fixation groove  440  at a distal end thereof. The sensor fixation arm  420  of the locator rod  400  is configured such that a sensor  410 , such as an infrared sensor, may be attached thereto. Hereinafter, the sensor  410  will be described as infrared sensor  410 ; however, this is merely exemplary and other sensors may be used for equivalent purposes; for example, the locator rod  400  may have other wired and wireless sensors attached thereto. The infrared sensor  410  provides data to a neuro-navigation computer (not-illustrated) to link the data about a patient&#39;s brain from the infrared sensor  410  to magnetic resonance imaging (MRI) images of the patient&#39;s brain. Such configuration allows for the infrared sensor  410  data visualization of tissue, such as a tumor, in real time correlated onto the MRI image. The fixed length increment lines  430  allow for a neuro navigational computer to calculate precise spatial points in conjunction with the data from the infrared sensor  410 . 
         [0029]    The locator rod  400  is seen separate on a neuro navigation computer and according to exemplary embodiments, is not affixed to a patient or table. The locator rod  400  may also be configured to incorporate the sensors as exemplarily discussed below. 
         [0030]    The gasket fixation groove  440  of the locator rod  400  is configured such that a gasket  450  may be fit thereto similarly as described with respect to the gasket  200  and gasket fixation groove  210  of  FIG. 1 . 
         [0031]      FIG. 4 a    illustrates an MIS retractor tube with integrated sensors  4000   a . The MIS retractor tube with integrated sensors  4000   a  includes a retractor tube  180  with integrated neuro-monitoring points  140 , neuro-monitoring receptacle  150  and reflector ball  160 . The retractor tube  180  also includes a base plate  170  in which a retractor fixation point  130   a  and retractor fixation point  130   b  are provided. The retractor tube  180  may be of fixed length, as exemplarily described for  FIG. 1  or may be of expandable length as further described with respect to  FIG. 5   a.    
         [0032]    The reflector ball  160  and the neuro-monitoring points  140 , respectively incorporate sensors, of the retractor tube  180  provide data used by a neuro navigation computer to link the patient&#39;s brain to MRI images thereby allowing visualization of tissues, such as a tumor, real time correlated onto MRI images. The positions of the neuro-monitoring points  140  allow a neuro navigation computer to calculate precise spatial points. The neuro-monitoring points  140  are spaced about the circumference of the retractor tube  180  at equidistant intervals  142   d.    
         [0033]    The neuro-monitoring receptacle  150  provides data allowing for a surgeon to hear a loud tone, such as from compression to a nerve during surgery, and is a grounded system. According to exemplary embodiments, the retractor fixation point  130   a  may be used to position the retractor tube  180  and the retractor fixation point  130   b  may be used to fix the base plate  170  of the retractor tube  180  to a patient tissue, such as a bone. 
         [0034]      FIG. 4 b    illustrates an MIS retractor tube with integrated sensors  4000   b.  The MIS retractor tube with integrated sensors  4000   b  includes the retractor tube  180  of  FIG. 4 a    which includes the retractor fixation point  130   a,  neuro-monitoring receptacle  150 , reflector ball  160 , and base plate  170 . As illustrated in  FIG. 4 b   , the neuro-monitoring points  140  are not only equidistantly located about respective circumferences of the retractor tube  180  but are also located at equidistant intervals  141   d  along the longitudinal length of the retractor tube  180  according to the exemplary embodiment of  FIG. 4 b   . As discussed above, the position of the neuro-monitoring points  140  provide a compute with spatial information, such as a depth of the retractor. 
         [0035]      FIG. 5 a    illustrates an MIS Retractor tube with sleeve  5000   a . The MIS Retractor tube with sleeve  5000   a  includes expandable tube retractor  500  having a base plate  170  upon which a navigation fixation point  110 , a retractor fixation point  130   a,  a retractor fixation point  130   b,  a threaded rod  510  and a screw  520  are mounted. The expandable tube retractor  500  also includes an expandable sleeve  540  surrounding an iris cylinder  530 . 
         [0036]    The expandable tube retractor  500  is configured such that interlocking veins of the iris cylinder  530  are actuated according to an action of the screw  520  and threaded rod  510  or other equivalent methods of actuation to expand or retract the iris cylinder  530 . As the iris cylinder  530  expands, so does the expandable sleeve  540  which covers an exterior of the expandable sleeve  540 . 
         [0037]      FIG. 5 b    illustrates an MIS Retractor tube with sleeve  5000   b.  The MIS Retractor tube with sleeve  5000   b  illustrates that the expandable sleeve  540  covers an exterior of the iris cylinder  530 . The expandable sleeve  540  improves the friction and cushioning of the expandable tube retractor  500  to protect and preserve patient tissue and also to prevent prolapse and herniation of patient tissue into the expandable tube retractor  500 . According to exemplary embodiments, the length  5041  of the expandable sleeve  540  is greater than the length  5301  of the iris cylinder  530 . 
         [0038]      FIG. 6  illustrates a flowchart  6000  of placing a retractor tube, such as the retractor tube  100  of  FIG. 1 . 
         [0039]    At S 601 , a locator rod, such as locator rod  400 , is inserted into a human tissue such as during brain or spinal surgery. The locator rod may have a gasket attached to a distal end thereof. 
         [0040]    At S 602 , the data retrieved from the locator rod is used to identify if the locator rod has been inserted at a desired a surgical site. If not, the locator rod is reinserted into a different location of tissue. 
         [0041]    At S 603 , a series of dilating tubes are placed at the desired surgical site, such as described for the dilating tubes  301 - 305 . The dilating tubes may have respective gaskets attached to distal ends thereof. 
         [0042]    At S 604 , a retractor tube, such as retractor tube  100  is placed into the tissue dilated by the series of dilating tubes. The retractor tube may have a gasket attached to a distal end thereof. 
         [0043]    At S 605 , the retractor tube is fixed. For example a baseplate of the retractor tube may be fixed to a boney structure such as a skull during brain surgery or to an attachment arm that is securable to an operating room bed. 
         [0044]    At S 606 , further neuro monitoring and/or neuro navigation devices are attached to the retractor tube. 
         [0045]      FIG. 7  illustrates a flowchart  7000  of placing an expandable surgical retractor, such as the expandable tube retractor  500  of  FIG. 5   a.    
         [0046]    At S 701 , a locator rod, such as locator rod  400 , is inserted into a human tissue such as during brain or spinal surgery. The locator rod may have a gasket attached to a distal end thereof. 
         [0047]    At S 702 , the data retrieved from the locator rod is used to identify if the locator rod has been inserted at a desired a surgical site. If not, the locator rod is reinserted into a different location of tissue. 
         [0048]    At S 703 , an expandable retractor is placed at the desired surgical site. The expandable retractor may have an expandable sleeve attached to an exterior of an expandable retractor tube of the expandable retractor. 
         [0049]    At S 704 , the expandable retractor is expanded as is the expandable sleeve. 
         [0050]    At S 705 , the expandable retractor is fixed. For example a baseplate of the expandable retractor may be fixed to a boney structure such as a skull during brain surgery or to an attachment arm that is securable to an operating room bed. 
         [0051]    At S 706 , further neuro monitoring and/or neuro navigation devices are attached to the expandable retractor. 
         [0052]    While the present invention has been described with respect to certain preferred embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the following claims. 
       INDUSTRIAL APPLICABILITY 
       [0053]    The negative ramifications to these design modifications are the potential of harming the patient with active use. However, this is by nature an acceptable risk that the patient incurs with consent to an operation. 
         [0054]    According to the CDC, in the United States, the proportion of the population aged &gt;65 years is projected to increase from 12.4% in 2000 to 19.6% in 2030. The number of persons aged &gt;65 years is expected to increase from approximately 35 million in 2000 to an estimated 71 million in 2030, and the number of persons aged &gt;80 years is expected to increase from 9.3 million in 2000 to 19.5 million in 2030. The increased number of persons aged &gt;65 years will potentially lead to increased health-care costs. The health-care cost per capita for persons aged &gt;65 years in the United States and other developed countries is three to five times greater than the cost for persons aged &lt;65 years, and the rapid growth in the number of older persons, coupled with continued advances in medical technology, is expected to create upward pressure on health- and long-term-care spending. With the projected growth of the “Baby Boomer” population, the need for surgical intervention is expected to grow. By reducing post-surgical recovery time, surgery time and potential injury exposure, this can lead to cost savings both in healthcare dollars and litigation expenses. 
       REFERENCE SIGNS LIST 
       [0000]    
       
         
           
               100  RETRACTOR TUBE 
               101  FIXED LENGTH 
               110  NAVIGATION FIXATION POINT 
               120  DISTAL END 
               130   a  RETRACTOR FIXATION POINT 
               130   b  RETRACTOR FIXATION POINT 
               140  NEURO-MONITORING POINTS 
               141   d  INTERVALS 
               142   d  INTERVALS 
               150  NEURO-MONITORING RECEPTACLE 
               160  REFLECTOR BALL 
               170  BASE PLATE 
               180  RETRACTOR TUBE 
               200  GASKET 
               210  GASKET FIXATION GROOVE 
               301 - 305  DILATING TUBES 
               311 - 315  GASKET FIXATION GROOVES 
               321 - 325  GASKETS 
               400  LOCATOR ROD 
               410  SENSOR 
               420  SENSOR FIXATION ARM 
               430  FIXED LENGTH INCREMENT LINES 
               440  GASKET FIXATION GROOVE 
               450  GASKET 
               500  EXPANDABLE TUBE RETRACTOR 
               510  THREADED ROD 
               520  SCREW 
               530  IRIS CYLINDER 
               5301  LENGTH 
               540  EXPANDABLE SLEEVE 
               5401  LENGTH 
               1000  MIS RETRACTOR TUBE WITH NAVIGATION FIXATION POINT AND PROTECTIVE GASKET 
               2000  MIS DILATING TUBES WITH GASKET AND GASKET FIXATION GROOVES 
               3000  MIS LOCATOR ROD WITH GASKET AND GASKET FIXATION GROOVES 
               4000   a,    4000   b  MIS RETRACTOR TUBE WITH INTEGRATED SENSORS 
               5000   a,    5000   b  MIS RETRACTOR TUBE WITH SLEEVE 
               6000  METHOD OF PLACING RETRACTOR TUBE 
               7000  METHOD OF PLACING AN EXPANDABLE SURGICAL RETRACTOR 
           
         
       
     
       CITATION LIST 
       [0000]    
       
         
           
             US 20070208229 A1 
             U.S. Pat. No. 8,303,497 B2 
             US 20130006059 A1