Patent Publication Number: US-8974380-B2

Title: Surgical retractor

Description:
REFERENCE TO CROSS-RELATED APPLICATION 
     This application is a continuation-in-part of U.S. patent application Ser. No. 12/980,395, filed on Dec. 29, 2010, which is a continuation-in-part of U.S. patent application Ser. No. 12/880,162, filed on Sep. 13, 2010, which is a continuation-in-part of U.S. patent application Ser. No. 12/814,492, filed on Jun. 14, 2010, which claims priority from U.S. provisional patent application No. 61/307,469, filed on Feb. 24, 2010. 
     This application claims priority benefits from U.S. patent application Ser. No. 12/980,395, filed on Dec. 29, 2010, herein incorporated by reference in its entirety, which claims priority from U.S. patent application Ser. No. 12/880,162, filed on Sep. 13, 2010, herein incorporated by reference in its entirety, which claims priority from U.S. patent application Ser. No. 12/814,492, filed on Jun. 14, 2010, herein incorporated by reference in its entirety, which claims priority from U.S. provisional application No. 61/307,469, filed on Feb. 24, 2010, herein incorporated by reference in its entirety 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to apparatus and techniques for performing minimally invasive surgery and, in particular to a retractor device for minimally invasive surgery, more particularly to a new expanding retractor for spinal minimal invasive neurosurgery. 
     BACKGROUND OF THE INVENTION 
     A concentrically expansible needle retractor for minimally invasive surgery, of one the present inventors, is described in PCT/IL2000/00387, filed Jul. 4, 2000, the full disclosures of which are incorporated herein by reference. 
     An improved radial expansible retractor for minimally invasive surgery, of the present inventors, is described in PCT/IL2006/001250, filed Oct. 30, 2006, which has significant improvements which can benefit patients, the full disclosures of which are incorporated herein by reference. 
       FIG. 1   a  of the prior art is a perspective view schematic illustration of the improved radial expansible retractor, which will be referred to in the present application as a prior art radial expansible retractor (PARER)  100 . 
     The illustrations show PARER ribs  141  touching each other, forming a hollow cylinder. 
     The prior art radial expansible retractor  100  is equipped with a PARER adaptor  169  and with a mechanism for transmitting gentle rotational mechanical movement from a PARER rotating wheel  161  to a PARER grooved disc  152 , (not shown in the present illustrations). 
       FIG. 1   b  of the prior art is a perspective view schematic illustration of a PARER cover  151 , of the prior art radial expansible retractor, in whose center is a PARER cover central perforation  151   a  of a suitable diameter for inserting a tubule and performing the medical procedure. 
       FIG. 1   c  of the prior art is a perspective view schematic illustration of a PARER grooved disc  152 , of the prior art radial expansible retractor, in whose center is a PARER grooved disc central perforation  152   a , of a suitable diameter for inserting the tubule and performing the medical procedure, and PARER grooves  152   b , in the present case eight, designated to grant continuous forced movement to rib carrier pins. 
     In the case of need to open a shape other than a circle, the PARER grooved disc  152  can be used with at least part of the grooves having a different curve, and ends at different distances from the center. This difference necessarily results in different movement of each of the ribs, forming a lateral section, which is not circular. 
     Namely, the desired opening shape to be achieved by means of prior art radial expansible retractor must be determined prior to commencement of the medical operation. 
       FIG. 1   d  of the prior art is a perspective view schematic illustration of a of PARER channeled disc  153 , of the prior art radial expansible retractor  100 , in whose center is a PARER channeled disc central perforation  153   a , of a suitable diameter for inserting the tubule and performing the medical procedure, and PARER channels  153   b , in the present case eight, designated to grant continuous forced movement to the rib carrier, (not shown in the present figure). The PARER channels  153   b  are completely straight, and are pointed in the directions of the radiuses from a joint center of the PARER channeled disc  153 . Their dimensions conform to those of rib carrier, and they are designated to enable strictly radial movement of PARER rib carrier  144 , (not shown in the present figure), with regard to the aforementioned center. 
     Combination of the PARER channeled disc  153  and the PARER cover disc  151  is done by means of geometrically conforming both to each other, together forming a casing suitable for carrying PARER grooved disc  152  and granting it smooth rotational movement. 
       FIG. 1   e  of the prior art is lateral section schematic illustrations of the prior art radial expansible retractor  100 . 
     The figure clearly showing PARER rib carrier  144  disposed within PARER channel  153   b  of the PARER channeled disc  153 , with a PARER rib carrier pin  145  disposed within PARER groove  152   b  of the PARER grooved disc  152 . The PARER rib carrier  144  connects to PARER rib base  142 , which is the integral base of PARER rib  141 , by means of PARER rib carrier bolt  147 . 
       FIG. 1   f  of the prior art is a perspective view schematic illustration of a PARER rib  141  of the prior art radial expansible retractor. 
     At one end of PARER rib  141 , the PARER rib&#39;s base  142  is disposed, into which the PARER rib base hole  143  is perforated. PARER rib  141  is formed as an elongated rod whose cross section can have many various geometrical shapes, also including the shape of a section of the wall of a cylinder. 
       FIG. 1   g  of the prior art is a perspective view schematic illustration of a PARER rib carrier  144  of the prior art radial expansible retractor. Its shape conforms for connection to the PARER rib&#39;s base  142  and it includes PARER rib carrier hole  146 , and PARER rib carrier pin  145 . 
     As far as minimal invasive methods of treatment of spinal stenosis are concerned, they are commonly performed with the assistance of tubular retractors. 
     A tubular retractor for minimally invasive surgery, of Bartie et al., is described in U.S. Pat. No. 6,210,325, granted Apr. 3, 2001, the full disclosures of which are incorporated herein by reference. 
     Use of tubular retractors for the performance of treatment of spinal stenosis has some very grave drawbacks, also including: 
     Over traumatization (disruption of muscles and nerves roots) of soft tissues upon insertion of a retractor, in most cases hammering is required to insert the retractor between muscle fibrils, resulting in destruction and disruption of soft tissues. During postoperative recovery, this kind of iatrogenic damage can inflict pain more severe than that caused by the pathology itself. 
     The tubular retractor frequently causes postoperative hemorrhaging and compression of the spinal cord, with motor function deterioration of the patient&#39;s extremities. 
     Uncontrolled soft tissue retraction (without measurement of retracted tissue pressure (RTP) and retracted tissue oxygen saturation (RTOS)) causes ischemic muscular degeneration-IMD and development of extremely rough postoperative scar tissue, resulting in circular compression of nerve roots and thus severe postoperative pain. 
     Very fast insertion of such tubular retractors causes splitting of muscles from vertebral bones and hemorrhaging. Surgeons must be aware that even though the surgery is completed effectively in a narrow space, symptoms can occur immediately if even a small hematoma is generated in this space. 
     Appropriate surgical tools and manual skills are required since surgeons must work in a narrow space. Further, there may be confusion regarding anatomical structures in such a limited space. Another problem is the limitations of effective decompression due to limited and constant (unchangeable, non-adjustable) diameters of tubular retractors. 
     Due to differing curvatures of vertebral lamina, tubular retractors don&#39;t enable the surgeon to approach lateral parts of lamina, including vertebral facets, and vision may be obstructed or disrupted by the use of tools in a narrow space with limited light. 
     Non-simultaneous unidirectional retraction of muscles causes uneven distribution of pressure to the soft tissues. Uncontrolled soft tissue retraction (without measurement of retracted tissue pressure (RTP) and retracted tissue oxygen saturation (RTOS)) causes ischemic muscular degeneration (IMD), and development of extremely rough postoperative scar tissue, resulting in circular compression of nerve roots and thus severe postoperative pain. 
     There is thus a widely recognized need for, and it would be highly advantageous to have, a surgical retractor for performing minimally invasive surgery, that will not have the aforementioned drawbacks, that will also enable working with massive tissue pressures to the extent that body tissues can apply, that will enable creating openings of various section shapes which can be changed in the course of operation, and that will be equipped with ribs of various shapes and sizes, that can be easily replaced without use of additional tools. 
     SUMMARY OF THE INVENTION 
     The surgical retractor according to the present invention further improves the performance currently available with the prior art. It enables creating openings in the human body in locations in which the tissue pressure on its ribs is significantly more powerful than in brain surgery, such as in operations in close proximity with to the spine, with the ribs of the surgical retractor subject to pressure of the adjacent muscles. 
     An additional improvement is enabling the option of determining the shape of the opening in the operated body created by the surgical retractor when opening, and even changing the shape as necessary throughout the operation. This is achieved by a combination of opening all ribs of the surgical retractor simultaneously as a circle and subsequent individual control of each separate rib&#39;s inclination angle. Another major improvement is in enabling the replacement, prior to commencement of use of the surgical retractor, of the ribs of the surgical retractor without any need for any additional tools. 
     Yet another significant improvement is the addition of a light source to the surgical retractor, which grants the operating surgeon high visibility of the working area. 
     Yet another significant improvement is the addition of a video camera to the surgical retractor, which grants the operating surgeon high visibility of the working area. 
     Yet another significant improvement is to receive integrated pictures on one screen from a video camera and outside microscope, inserted endoscopically or laparoscopically into the retractor channel and wound cavity. 
     The surgical retractor can also have a flexible sleeve, made for example of rubber or silicone, to prevent entry of surrounding tissue into the working channel. 
     Yet another significant improvement, according to embodiments of the present invention, is that most of the components of the surgical retractor are made of materials transparent to Röntgen rays (x-rays). 
     Yet another significant improvement is that retractor is made by fully biocompatible and FDA approved materials like ULTEM HU 1000 RESIN. 
     Yet another significant improvement is that retractor is fully disposable. 
     According to the present invention there is provided a surgical retractor including: (a) a ribs assembly, the ribs assembly including at least two ribs; (b) a mechanism for transferring of radial linear and rotational movement adapted to apply mechanical forces and moments to the ribs assembly; (c) a casing, the casing including: (i) a channeled disc wherein the mechanism for transferring of linear and rotational movement and the ribs assembly are mounted on the channeled disc; and (ii) a cover disc, wherein the cover disc is connected to the channeled disc; (d) a grooved disc mounted inside the casing, wherein the grooved disc has a grooved disc body, wherein in the grooved disc body, there are a grooved disc central perforation and at least two curved grooves, and wherein the grooved disc has a grooved disc teeth on the grooved disc outer surface; and (e) a transmission, for granting rotational movement to sais grooved disc, the transmission being mounted on the casing, wherein the transmission includes: (i) a transmission first cog wheel; and (ii) a transmission bolt head mechanically connected to the transmission first cog wheel, wherein the transmission first cog wheel is engaged with the grooved disc teeth. 
     According to further features of an embodiment of the present invention the transmission further includes: (iii) a transmission shaft mechanically connected to the transmission first cog wheel; and (iv) a transmission ring mechanically connected to the transmission bolt head, wherein the transmission is made of one cylindrical part. 
     According to further features of an embodiment of the present invention the channeled disc has a channeled disc upper surface and a channeled disc wall and a channeled disc transmission niche located on the channeled disc upper surface and on the channeled disc wall and wherein the transmission first cog wheel is at least partially located inside the channeled disc transmission niche. 
     According to further features of an embodiment of the present invention the surgical retractor further includes: (f) a wrench mounted on the transmission bolt head. 
     According to still further feature of an embodiment of the present invention the surgical retractor further including: (f) a central rod, the central rod includes: (i) a central rod tail having two central rod screws; and (ii) a central rod head dome having a central rod head dome interior thread, wherein the central rod head dome is connected to the a central rod tail, and wherein most of the central rod tail is located between the least two ribs; and (g) an auxiliary handle, the auxiliary handle has a auxiliary handle interior thread, wherein the auxiliary handle is connected to the central rod tail. 
     According to still further features of an embodiment of the present invention the surgical retractor further including: (f) at least one lamp mounted inside the casing; and (g) a camera mounted inside the casing. 
     According to still further features of an embodiment of the present invention the surgical retractor further including: (f) at least two sliders located inside the casing; (g) at least two angular adjustment bolts wherein each one of the angular adjustment bolts is screwed in another one of the least two angular adjustment bolts; and (h) a guarding cover mounted on the casing. 
     According to still further features of an embodiment of the present invention each one of cover disc, the channeled disc, the grooved disc, the ribs, the at least two sliders, the angular adjustment bolts, and the guarding cover is composed of material transparent to x-ray radiation. 
     According to still further features of an embodiment of the present invention each one of cover disc, the channeled disc, the grooved disc, the ribs, the at least two sliders, the angular adjustment bolts, and the guarding cover is composed of material fully biocompatible. 
     According to still further features of an embodiment of the present invention each one of the angular adjustment bolts has a linear adjustment bolt tail having a non-circular cross section shape. 
     According to still further features of an embodiment of the present invention the surgical retractor further includes: (f) at least two opening mechanism third type cog wheels, wherein each one of the least two opening mechanism third type cog wheels is mounted on another one of the bolt tails, wherein each one of the least two opening mechanism third type cog wheels has a opening mechanism third type cog wheel central hole having a non-circular cross section shape; and (g) an opening mechanism third type, for facilitating a uniform rotational movement opening of the ribs the opening mechanism third type is mounted on the least two opening mechanism third type cog wheels. 
     According to still furthers feature of an embodiment of the present invention the opening mechanism third type includes: (i) a opening mechanism third type bevel gear ring. 
     According to still further features of an embodiment of the present invention the opening mechanism third type includes: (ii) an opening mechanism third type housing having an opening mechanism third type housing wall and at least two opening mechanism third type housing wall holes located in the opening mechanism third type housing wall, wherein the each one of the least two linear adjustment bolt tail is located inside another one of the at least two opening mechanism third type housing wall holes. 
     According to the present invention there is provided a method of minimally invasive operation, the method including the stages of: (a) making an incision of skin until superficial fascia; (b) holding an auxiliary handle of a surgical retractor; (c) inserting ribs and a central rod of the surgical retractor into a patient body; (d) removing the auxiliary handle from the surgical retractor; (e) rotating a wrench for granting rotational movement to a grooved disc causing radial linear opening movement of the ribs; (f) removing the central rod from the surgical retractor; and (g) removing the wrench from the surgical retractor. 
     According to further features of an embodiment of the present invention the method of minimally invasive operation further includes: (h) performing a medical procedure selected from a group consisting of replacing intravertebral discuses, removal of intravertebral discuses, fusion of vertebra, operations of anterior cervical discectomy and fusion, operations of trans laminar burr hole and discectomy, far lateral discectomy and discoplasty, multi level spinal stenosis, multi level uni-lateral and bilateral laminotomy, and trans-oral vertebral fusion; (i) closing the surgical retractor&#39;s ribs; (j) taking out the surgical retractor from the patient body; and (k) suturing a patient&#39;s skin. 
     According to still further feature of an embodiment of the present invention the method of minimally invasive operation further including: (h) making a burr hole lateral of lamina; (i) inserting additional instruments via the burr hole; (j) performing discectomy; (k) closing the surgical retractor&#39;s ribs; (l) taking out the surgical retractor from the patient body; and (m) suturing a patient&#39;s skin. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein: 
         FIG. 1   a  of the prior art is a perspective view schematic illustration of a prior art radial expansible retractor. 
         FIG. 1   b  of the prior art is a perspective view schematic illustration of a cover of the prior art radial expansible retractor. 
         FIG. 1   c  of the prior art is a perspective view schematic illustration of a grooved disc of the prior art radial expansible retractor. 
         FIG. 1   d  of the prior art is a perspective view schematic illustration of a channeled disc of the prior art radial expansible retractor. 
         FIG. 1   e  of the prior art is lateral section schematic illustrations of part of the prior art radial expansible retractor. 
         FIG. 1   f  of the prior art is a perspective view schematic illustration of a rib of the prior art radial expansible retractor. 
         FIG. 1   g  of the prior art is a perspective view schematic illustration of a rib carrier of the prior art radial expansible. 
         FIG. 2   a , is an isometric side top view schematic illustrations of a surgical retractor according to a first embodiment of the present invention. 
         FIG. 2   b , is an exploded, isometric side top view schematic illustrations of a surgical retractor, up to main assemblies, according to the first embodiment of the present invention. 
         FIG. 2   c , is an exploded, isometric side top view schematic illustrations of a surgical retractor, up to elements, according to the first embodiment of the present invention. 
         FIG. 3   a  is a top view schematic illustration of a surgical retractor, without adaptor, according to the first embodiment of the present invention, upon which a section plane a-a is marked. 
         FIG. 3   b  is a cross sectional view a-a illustration of a surgical retractor, according to the first embodiment of the present invention. 
         FIG. 4   a  is a top view schematic illustration of a guarding ring, according to the first embodiment of the present invention, upon which a section plane b-b is marked. 
         FIG. 4   b  is a side view schematic illustration of the guarding ring, according to the first embodiment of the present invention. 
         FIG. 4   c  is a top view schematic illustration of a lighting source supporter, according to the first embodiment of the present invention, upon which a section plane c-c is marked. 
         FIG. 4   d  is an isometric front bottom view schematic illustration of a lighting source supporter, according to the first embodiment of the present invention. 
         FIG. 4   e  is an exploded side view schematic illustration of a lighting assembly, according to the first embodiment of the present invention. 
         FIG. 4   f  is an exploded isometric front top view schematic illustration of a lighting assembly, according to the first embodiment of the present invention. 
         FIG. 4   g  is a side view schematic illustration of a lighting assembly, according to the first embodiment of the present invention. 
         FIG. 4   h  is a cross sectional view b-b illustration of a guarding ring and a cross sectional view c-c illustration of a lighting source supporter according to the first embodiment of the present invention. 
         FIG. 5   a  is an isometric front top view schematic illustration of a cover disc, according to the first embodiment of the present invention. 
         FIG. 5   b  is a side view schematic illustration of a cover disc, according to the first embodiment of the present invention. 
         FIG. 5   c  is an isometric bottom view schematic illustration of a cover disc and lighting source supporter, according to the first embodiment of the present invention. 
         FIG. 5   d  is an isometric front top view schematic illustration of a cover disc, and of lighting source supporter, according to the first embodiment of the present invention. 
         FIG. 6   a  is an isometric front top view schematic illustration of a grooved disc, according to the first embodiment of the present invention. 
         FIG. 6   b  is side view schematic illustration of a grooved disc, according to an embodiment of the present invention. 
         FIG. 6   c  is bottom view schematic illustration of a grooved disc and a central rod, according to the first embodiment of the present invention. 
         FIG. 7   a  is side view schematic illustration of a central rod, according to the first embodiment of the present invention. 
         FIG. 7   b  is bottom view schematic illustration of a central rod head dome, according to the first embodiment of the present invention. 
         FIG. 8   a  is an isometric front top view schematic illustration of a channeled disc, according to the first embodiment of the present invention. 
         FIG. 8   b  is side view schematic illustration of a channeled disc, according to the first embodiment of the present invention. 
         FIG. 8   c  is bottom view schematic illustration of a channeled disc, according to the first embodiment of the present invention, upon which a section plane d-d is marked. 
         FIG. 8   d  is cross sectional view d-d illustration of a track, according to the first embodiment of the present invention. 
         FIG. 9   a  is an isometric front top view schematic illustration of casing, according to an embodiment of the present invention. 
         FIG. 9   b  is a side view schematic illustration of a casing, according to the first embodiment of the present invention. 
         FIG. 9   c  is an exploded side view schematic illustration of casing, according to the first embodiment of the present invention. 
         FIG. 9   d  is a side view schematic illustration of a casing bolt, according to an embodiment of the present invention. 
         FIG. 10   a  is an isometric side top view schematic illustration of a rib and a slider combined together, according to the first embodiment of the present invention. 
         FIG. 10   b  is an exploded isometric side top view schematic illustration of a slider, according to the first embodiment of the present invention. 
         FIG. 10   c  is a top view schematic illustration of a slider main body, according to the first embodiment of the present invention, upon which a section plane e-e is marked. 
         FIG. 10   d  is a cross sectional view e-e illustration of a slider main body, according to the first embodiment of the present invention. 
         FIG. 10   e  is a partial side view schematic illustration of a rib, according to the first embodiment of the present invention. 
         FIG. 10   f  is a partial side view schematic illustration of a rib and a slider, according to the first embodiment of the present invention. 
         FIG. 10   g  is a partial side view schematic illustration of a rib and a slider, according to the first embodiment of the present invention. 
         FIG. 10   h  is a side view schematic illustration of a rib, an angular adjustment bolt and a slider, partially sectioned, according to the first embodiment of the present invention. 
         FIG. 10   i  is a side view schematic illustration of a slider, according to the first embodiment of the present invention. 
         FIG. 11  is a side view schematic illustration of a rib, an angular adjustment bolt and a slider, partially sectioned, in six stages of separation, according to the first embodiment of the present invention. 
         FIG. 12   a  is a side view schematic illustration of a rib, according to the first embodiment of the present invention. 
         FIG. 12   b  is a side view schematic illustration of a rib, according to the first embodiment of the present invention. 
         FIG. 12   c  is a side view schematic illustration of two ribs, according to the first embodiment of the present invention. 
         FIG. 13   a  is a side view schematic illustration of a rib, according to the first embodiment of the present invention, upon which a section plane f-f is marked. 
         FIG. 13   b  is a cross sectional view f-f illustration of a rib, according to the first embodiment of the present invention. 
         FIG. 13   c  is six cross sectional views f-f illustration of six ribs, according to the first embodiment of the present invention. 
         FIG. 14   a  is a side view schematic illustration of a rib, according to the first embodiment of the present invention. 
         FIG. 14   b  is a side view schematic illustration of a rib with a rib hook, according to the first embodiment of the present invention. 
         FIG. 14   c  is a side view schematic illustration of a rib, according to the first embodiment of the present invention. 
         FIG. 14   d  is an isometric view schematic illustration of six ribs, and a flexible sleeve, according to the first embodiment of the present invention. 
         FIG. 14   e  is a side view schematic illustration of a rib having rib segments, in a relaxed state, according to the first embodiment of the present invention. 
         FIG. 14   f  is a side view schematic illustration of rib having rib segments, in a flexed state, according to the first embodiment of the present invention. 
         FIG. 14   g  is an isometric view schematic illustration of a rib, having rib segments, in a relaxed state, according to the first embodiment of the present invention. 
         FIG. 14   h  is an isometric view schematic illustration of a rib, having rib segments, in a relaxed state, according to the first embodiment of the present invention, with the rib segments distanced from each other. 
         FIG. 15   a  is an isometric top view schematic illustration of a transmission, partially exploded, according to the first embodiment of the present invention. 
         FIG. 15   b  is an isometric bottom view schematic illustration of a transmission, partially exploded, according to the first embodiment of the present invention. 
         FIG. 16   a  is a top view schematic illustration of a carrier, according to the first embodiment of the present invention. 
         FIG. 16   b  is a back view schematic illustration of a carrier, according to the first embodiment of the present invention. 
         FIG. 16   c  is a side view schematic illustration of a carrier, according to the first embodiment of the present invention. 
         FIG. 16   d  is an isometric top view schematic illustration of a carrier, and a transmission, according to the first embodiment of the present invention. 
         FIG. 16   e  is an isometric bottom view schematic illustration of a carrier, and a channeled disc, according to the first embodiment of the present invention. 
         FIG. 17   a  is an isometric side top view schematic illustration of a carrier, and an adaptor, according to the first embodiment of the present invention. 
         FIG. 17   b  is an exploded isometric side top view schematic illustration of a carrier, and an adaptor, according to the first embodiment of the present invention. 
         FIG. 18   a  is an isometric side top view schematic illustration of six ribs, in a closed state, according to the first embodiment of the present invention. 
         FIG. 18   b  is an isometric side top view schematic illustration of six ribs, in an opened state, according to the first embodiment of the present invention. 
         FIG. 18   c  is an isometric side top view schematic illustration of six ribs, in a closed state, according to the first embodiment of the present invention. 
         FIG. 18   d  is an isometric side top view schematic illustration of six ribs, in an opened state, according to the first embodiment of the present invention. 
         FIG. 18   e  is an isometric side top view schematic illustration of six ribs, in an opened state, according to the first embodiment of the present invention. 
         FIG. 18   f  is a bottom view schematic illustration of six ribs, according to an embodiment of the present invention. 
         FIG. 19   a  is a bottom view schematic illustration of a grooved disc, and six sliders, in closed state, according to the first embodiment of the present invention. 
         FIG. 19   b  is a bottom view schematic illustration of a grooved disc, and six sliders in opened state, according to the first embodiment of the present invention. 
         FIG. 20  is a side view schematic illustration of a rib having sensors, and a block diagram of transducers, according to the embodiments of the present invention. 
         FIG. 21  is a side view schematic illustration of a surgical retractor after penetration and opening for the purpose of performing spinal minimal invasive neurosurgery, according to the embodiments of the present invention. 
         FIG. 22  is a side view schematic illustration of two surgical retractors after penetration and opening for the purpose of performing spinal minimal invasive neurosurgery, according to the embodiments of the present invention. 
         FIG. 23  is a side view schematic illustration of a rib having a rib hook, inside skin and muscle, according to the embodiments of the present invention. 
         FIG. 24  is a side view schematic illustration of a surgical retractor at three different angles, according to the embodiments of the present invention. 
         FIG. 25  is a side view schematic illustration of a surgical retractor at two different angles, according to the embodiments of the present invention. 
         FIG. 26  is an isometric view schematic illustration of a surgical retractor connected to holding arms, according to the embodiments of the present invention. 
         FIGS. 27   a - 27   f  are side view schematic illustrations of a surgical retractor at six different stages of opening within the operated patient&#39;s body, in accordance with the embodiments of the present invention. 
         FIG. 28  is a flow chart that schematically illustrates a method of operation for decompression of spinal stenosis, in accordance with the embodiments of the present invention. 
         FIG. 29   a  is an isometric front top view schematic illustration of a surgical retractor according to a second embodiment of the present invention. 
         FIG. 29   b  is a side view schematic illustration of a surgical retractor according to the second embodiment of the present invention. 
         FIG. 30  is an exploded, isometric front top view schematic illustration of a surgical retractor, according to the second embodiment of the present invention. 
         FIG. 31   a  is a side view schematic illustrations of a segment of a channeled disc, an angular adjustment bolt, a linear adjustment bolt, a slider, a slider pivot, and a rib of the surgical retractor, according to the second embodiment of the present invention. 
         FIG. 31   b  is an isometric front top view schematic illustration of a channeled disc, an angular adjustment bolt, a linear adjustment bolt, a slider, and a rib of the surgical retractor, according to the second embodiment of the present invention. 
         FIG. 32   a  is a top view schematic illustration of the channeled disc of a surgical retractor, according to the second embodiment of the present invention, upon which a section plane g-g is marked. 
         FIG. 32   b  is a cross sectional view g-g illustrations of the channeled disc of the surgical retractor, according to the second embodiment of the present invention. 
         FIG. 33  is a top view schematic illustration of a surgical retractor, according to the second embodiment of the present invention, upon which a section plane h-h is marked. 
         FIG. 34  is a cross sectional view h-h illustrations of the surgical retractor, according to the second embodiment of the present invention. 
         FIG. 35   a  is a top view schematic illustration of a slider of the surgical retractor, according to the second embodiment of the present invention, upon which a section plane i-i is marked. 
         FIG. 35   b  is a cross sectional view i-i illustrations of a slider of the surgical retractor, according to the second embodiment of the present invention. 
         FIG. 36   a  is an isometric front top view schematic illustration of a surgical retractor, equipped with an opening mechanism first type, according to the second embodiment of the present invention. 
         FIG. 36   b  is a side view schematic illustration of a surgical retractor equipped with an opening mechanism first type, according to the second embodiment of the present invention. 
         FIG. 37  is an exploded, isometric front top view schematic illustration of a surgical retractor of  FIG. 36   a , according to the second embodiment of the present invention. 
         FIG. 38  is a top view schematic illustration of a surgical retractor, equipped with an opening mechanism first type, according to the second embodiment of the present invention, upon which a section plane j-j is marked. 
         FIG. 39  is a cross sectional view j-j illustration of a surgical retractor, equipped with an opening mechanism first type, according to the second embodiment of the present invention. 
         FIG. 40  is a side view schematic illustration of an angular adjustment bolt, a slider, a slider pivot, and a rib of a surgical retractor, according to the second embodiment of the present invention. 
         FIG. 41  is an isometric front top view schematic illustration of a slider, and an opening mechanism slider of a surgical retractor, according to the second embodiment of the present invention. 
         FIG. 42  is an isometric front top view schematic illustration of a slider, and a segment of an external disc of a surgical retractor, according to the second embodiment of the present invention. 
         FIG. 43  is an exploded, isometric front top view schematic illustration of an opening mechanism first type of a surgical retractor, according to the second embodiment of the present invention. 
         FIG. 44   a  is an exploded, isometric top view schematic illustration of an opening mechanism second type of a surgical retractor, according to the second embodiment of the present invention. 
         FIG. 44   b  is an isometric front top view schematic illustration of an opening mechanism second type of a surgical retractor, according to the second embodiment of the present invention. 
         FIG. 45   a  is a front view schematic illustration of a surgical retractor, according to a third embodiment of the present invention. 
         FIG. 45   b  is an isometric top view schematic illustration of a surgical retractor, according to a third embodiment of the present invention. 
         FIG. 46 , is an exploded, isometric side bottom view schematic illustration of a surgical retractor, up to elements, according to the third embodiment of the present invention. 
         FIG. 47   a , is an isometric front top view schematic illustration of a grooved disc, a slider, an angular adjustment bolt and a transmission, according to the third embodiment of the present invention. 
         FIG. 47   b , is an isometric front bottom view schematic illustration of a grooved disc, a slider, an angular adjustment bolt and a transmission, according to the third embodiment of the present invention. 
         FIG. 48  is an isometric front top view schematic illustration of a transmission, according to the third embodiment of the present invention. 
         FIG. 49   a  is an isometric front top view schematic illustration of a channeled disc, according to the third embodiment of the present invention. 
         FIG. 49   b  is an isometric front top view schematic illustration of a channeled disc and a transmission, according to the third embodiment of the present invention. 
         FIG. 49   c  is an isometric front bottom view schematic illustration of a channeled disc, according to the third embodiment of the present invention channeled disc long slots  13   f.    
         FIG. 50  is an isometric front top view schematic illustration of a guarding cover, according to the third embodiment of the present invention. 
         FIG. 51   a  an isometric front top view schematic illustration of a slider and an angular adjustment bolt, according to the third embodiment of the present invention. 
         FIG. 51   b  is an exploded, isometric front top view schematic illustration of a slider, according to the third embodiment of the present invention. 
         FIG. 52  is a side view schematic illustration of a casing, according to the third embodiment of the present invention 
         FIG. 53   a  is a top view schematic illustration of the surgical retractor, according to the third embodiment of the present invention, upon which a section plane k-k is marked. 
         FIG. 53   b  is a cross sectional view k-k illustration of the surgical retractor, according to the third embodiment of the present invention. 
         FIG. 53   c  is a cross sectional view k-k illustration of three elements of the surgical retractor, according to the third embodiment of the present invention. 
         FIG. 54  is a side view schematic illustration of the surgical retractor, equipped with an opening mechanism third type, according to the third embodiment of the present invention. 
         FIG. 55   a  is a side view schematic illustration of an angular adjustment bolt, according to some variant of the third embodiment of the present invention, upon which a section plane l-l is marked. 
         FIG. 55   b  is a cross sectional view l-l illustration of the angular adjustment bolt, according to some variant of the third embodiment of the present invention. 
         FIG. 56  is an isometric side top view schematic illustration of a opening mechanism third type cog wheel, according to some variant of the third embodiment of the present invention. 
         FIG. 57   a  is an exploded isometric front bottom view schematic illustration of an opening mechanism third type, and angular adjustment bolts, according to some variant of the third embodiment of the present invention. 
         FIG. 57   b  is an exploded isometric front top view schematic illustration of an opening mechanism third type  60   c , and angular adjustment bolts  14   a , according to some variant of the third embodiment of the present invention. 
         FIG. 58   a  is a side view schematic illustration of a surgical retractor, according to the third embodiment of the present invention, after insertion and opening for the purpose of performing far lateral micro discectomy and discoplasty (FLMDD). 
         FIG. 58   b  is a side view schematic illustration of a surgical retractor, according to the third embodiment of the present invention, after insertion and opening for the purpose of performing a translaminar micro discectomy. 
         FIG. 59  is a flow chart that schematically illustrates a method of operation for minimal invasive (MI), using a surgical retractor, according to the third embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     The present invention is a surgical retractor. The principles and operation of a surgical retractor according to the present invention may be better understood with reference to the drawings and the accompanying description. 
     Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. 
     Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, dimensions, methods, and examples provided herein are illustrative only and are not intended to be limiting. 
     The following list is a legend of the numbering of the application illustrations:
           2  surgical retractor     10  mechanism for transferring of linear and rotational movements     11  cover disc     11   a  cover disc base     11   b  cover disc base     11   c  cover disc wall     11   d  cover disc wall hole     11   e  cover disc wall openings     11   f  cover disc supports     11   g  cover disc base hole     11   i  cover disc perforation     11   j  cover disc holding pin     12  grooved disc     12   a  grooved disc central perforation     12   ao  grooved disc central perforation center     12   b  curved groove     12   bo  groove radius origin     12   c  grooved disc outer surface     12   d  grooved disc hole     12   e  grooved disc teeth     12   f  grooved disc body     13  channeled disc     13   a  channeled disc base     13   b  channeled disc wall     13   c  channeled disc wall niche     13   d  channeled disc wall hole     13   e  channeled disc perforation     13   f  channeled disc long slot     13   g  channeled disc short slot     13   h  track     13   i  track side wall     13   j  track upper wall     13   k  channel     13   l  channel upper opening     13   m  channeled disc wall tenon     13   p  channeled disc wire hole     13   q  channeled disc lamp housing     13   r  channeled disc camera housing     13   s  channeled disc transmission niche     13   t  channeled disc upper surface     14   a  angular adjustment bolt     14   aa  angular adjustment bolt head     14   b  linear adjustment bolt     14   c  linear adjustment bolt head     14   d  linear adjustment bolt tail     14   e  non-circular cross section shape     15  slider     15   a  slider main body     15   b  slider upper body     15   c  slider pin hole     15   cl  movement toward closing     15   d  slider arm     15   e  slider pivot hole     15   f  slider among arms surface     15   g  slider niche     15   h  slider friction reducer     15   i  slider pin     15   j  slider pivot     15   m  slider first interior thread     15   n  slider second interior thread     15   op  movement toward opening     15   p  main slider upper portion     15   q  main slider mid portion     15   r  main slider lower portion     15   s  slider back portion     15   t  slider bolt     15   u  slider bolt hole     15   w  slider third interior thread     16  carrier     16   a  carrier bow     16   b  carrier bow bottom hole     16   c  carrier bridge     16   d  carrier bridge first hole     16   e  carrier bridge second hole     16   f  carrier arm     16   g  carrier back wall     16   h  carrier back wall hole     16   i  carrier bow side hole     16   j  carrier arm hole     17  transmission     17   a  transmission knob     17   b  transmission shaft     17   c  transmission worm     17   e  transmission tubular     17   f  transmission first cog wheel     17   g  transmission second cog wheel     17   h  transmission third cog wheel     17   i  transmission bolt head     17   j  transmission ring     18  base disc     19  external disc     19   h  external disc stair     20  ribs assembly     21  rib     21   a  concave segment of a rib front surface     21   b  rib back surface     21   c  convex segment of a rib back surface     21   d  rib shoulder     21   e  rib shoulder concave segment     21   f  rib front surface     21   fa  rib force arm     21   g  rib top end     21   h  rib bottom end     21   i  rib bottom end projection     21   j  rib force arm front surface     21   k  rib working arm front surface     21   m  rib hole     21   md  movement direction (of a rib)     21   n  rib hook     21   o  concave segment of a rib front surface origin     21   p  rib hook pin     21   q  rib segment     21   r  cable tensioner     21   rm  rotational movement (of a rib)     21   s  cable     21   t  anchoring point     21   wa  rib working arm     23  flexible sleeve     30  central rod     30   a  central rod tail     30   b  central rod tail slot     30   c  central rod head dome     30   s  central rod tail symmetrical line     31   a  central rod screw     32   a  central rod head dome interior thread     40  adaptor     40   a  adaptor rod     40   b  lock first part     40   c  lock second part     40   d  lock connector     40   e  lock fastener screw     40   f  clip     47  clamp     48  holding arm     50  lighting assembly     51  lighting source     51   a  lighting source supporter base     51   b  lamp     51   c  power source     51   d  electricity conductors     51   e  light reflector     51   f  lamp window     51   g  electric wire     52  lighting source supporter     52   a  lighting source supporter base     52   b  lighting source supporter wall     52   c  lighting source supporter wall slots     52   d  lighting source supporter wall shoulder     52   e  lighting source supporter wall groove     53  camera     53   a  camera cable     58  guarding cover     58   a  guarding cover disk     58   b  guarding cover perforation     58   c  guarding cover niche     58   d  guarding cover wall segment     58   e  guarding cover wall hole     59   a  auxiliary handle     59   aa  auxiliary handle interior thread     59   b  wrench (such as ratchet wrench)     60   a  opening mechanism first type     60   b  opening mechanism second type     60   c  opening mechanism third type     60   ca  opening mechanism third type cog wheel     60   cb  opening mechanism third type cog wheel central hole     60   cc  opening mechanism third type bevel gear ring     60   cd  opening mechanism third type housing     60   ce  opening mechanism third type housing wall     60   cf  opening mechanism third type housing wall hole     61   a  opening mechanism pole     61   b  opening mechanism cylinder     61   ba  opening mechanism cylinder external thread     61 D opening mechanism cylinder internal diameter     62  opening mechanism arms ring     62   a  opening mechanism arms ring central hole     62   b  opening mechanism arms ring arm     63  opening mechanism arm     63   a  opening mechanism arm upper pivot     63   b  opening mechanism arm lower pivot     64  opening mechanism slider     64   a  opening mechanism slider upper channel     64   b  opening mechanism slider bottom channel     64   c  opening mechanism slider side channel     64   d  opening mechanism slider pushing portion     65  opening mechanism base     65   a  opening mechanism base hole     65   b  opening mechanism base groove     65   c  opening mechanism base track     66  opening mechanism nut     66   a  opening mechanism nut body     66   b  opening mechanism nut internal thread     66   c  opening mechanism nut handle     70  casing     70   a  casing bolt     80   a  pressure sensor     80   b  tissue oxygen saturation sensor     80   c  transparent window     80   d  electrical conductor     80   e  pressure transducer     80   f  oxygen saturation sensor     90  body tissue     90   a  muscle     90   b  spinal canal     90   c  vertebra     90   d  incision line of lamina     90   e  bone     90   f  skin     90   k  lumbar vertebrae     90   l  discus     90   m  burr hole     91  wedge   fascia   F force (general)   F 1  adjustment bolt force   F 2  body tissue force   F 3  slider pivot force   F 4  test force   F 5  axial force   F 6  radial force   d 1  guarding ring interior diameter   d 2  lighting source supporter base ring interior diameter   d 3  lighting source supporter wall shoulder outer diameter   d 4  lighting source base interior diameter   d 5  slider pivot hole diameter   d 6  gap between the slider pivot and the slider among arms surface   d 7  concave segment of a rib front surface diameter   d 8  rib force arm length   d 9  rib working arm length   d 10  rib working arm projection to the center   d 11  rib force arm width   d 12  rib working arm width   d 13  rib bottom end deflection   d 14  slider arms gap   d 15  rib cross section head cut off length   d 16  rib thickness   d 17  central rod tail diameter   d 18  ribs interior diameter   d 19 (μ) slider pin distance from the grooved disc central perforation center   d 20  slider pivot distance from the grooved disc central perforation center   d 21  upper portion length   d 22  mid portion length   d 23  lower portion length   r 1  groove radius   r 2  channeled disc perforation radius   r 3  slider among arms surface radius   r 4  convex segment of a rib back surface radius   r 5  rib shoulder concave segment radius   α angle between the slider and the channeled disc   β angle between the rib force arm front surface to the rib working arm f front surface   γ rib cross section head angle   μ grooved disc rotational angle   δ rib opening angle     100  prior art radial expansible retractor (PARER)     141  PARER rib     142  PARER rib base     143  PARER rib base hole     144  PARER rib carrier     145  PARER rib carrier pin     146  PARER rib carrier hole     147  PARER rib carrier bolt     148  PARER central rod     151  PARER cover disc     151   a  PARER cover central perforation     152  PARER grooved disc     152   a  PARER grooved disc central perforation     152   b  PARER groove     153  PARER channeled disc     153   a  PARER channeled disc central perforation     153   b  PARER channel     161  PARER rotating wheel     169  PARER adaptor       

     Note: when there is need for distinction of association of a reference number to one of the three embodiments of the present invention, a reference number associated with the first embodiment will be marked with a single apostrophe, a reference number associated with the second embodiment will be marked with double apostrophes, and a reference number associated with the third embodiment will be marked with three apostrophes; for example: surgical retractor  2 ′, (in accordance with the first embodiment of the present invention), surgical retractor  2 ″, (in accordance with the second embodiment of the present invention) and surgical retractor  2 ′″, (in accordance with the second embodiment of the present invention). 
     Additional note: when, in the present patent application, there is use of terminology referring to the surgical retractor and/or its components, such as top, bottom, side, front, etc., the reference is to the relative axes of the surgical retractor, and is strictly for the purpose of facilitating understanding, and is not in any way limiting the present invention. 
     The first embodiment of the present invention will be described with reference to  FIGS. 2   a  to  19   b , the second embodiment of the present invention will be described with reference to  FIGS. 29   a  to  44   b , and the third embodiment of the present invention will be described with reference to  FIGS. 45 to 57   b.    
     The remaining illustrations refer to all the various embodiments of the present invention. These illustrations demonstrate that many elements and their combinations are common to the various embodiments of the present invention. 
     Referring now to the drawings,  FIG. 2   a , is an isometric side top view schematic illustration of a surgical retractor  2 ′ according to a first embodiment of the present invention. 
     The surgical retractor  2 ′ is shown in an assembled state. 
       FIG. 2   b , is exploded, isometric side top view schematic illustrations of a surgical retractor  2 ′, up to main assemblies, according to the first embodiment of the present invention. 
     The active assembly, which practically creates the opening in the operated patient&#39;s body for the purpose of performing the operation, is a ribs assembly  20 , which can have an integrated central rod  30 ′, which leads the penetration into the body. The ribs assembly  20  has a wide range of opening states, which will be described in further detail in the following. These opening states are commanded and controlled by a mechanism for transferring of linear and rotational movements  10 ′. In addition, the surgical retractor  2 ′, according to the present invention, can include a lighting assembly  50 ′ for the purpose of illuminating the operation area, a guarding cover  58 ′ to prevent entry of foreign objects, dust, dirt, etc., into the surgical retractor  2 ′, and adaptor  40  for the purpose of connection to a holder device. 
       FIG. 2   c , is exploded, isometric side top view schematic illustrations of a surgical retractor  2 ′, up to elements, according to the first embodiment of the present invention. 
     The lighting assembly  50 ′, according to the first embodiment of the present invention, includes lighting source  51  and lighting source supporter  52 . The mechanism for transferring of linear and rotational movement  10 ′, according to the first embodiment of the present invention, includes cover disc  11 ′, grooved disc  12 , channeled disc  13 ′, six angular adjustment bolts  14   a , six sliders  15 ′, a carrier  16 , and a transmission  17 ′. The ribs assembly  20 , according to the first embodiment of the present invention, includes six ribs  21 . 
     According to another variant of the present invention the quantity of ribs  21  is other than six, and therefore the quantities of the other elements, quantified as six in the present illustration, are correspondingly quantified. 
     The central rod  30 ′, according to a variant of the present invention, includes central rod tail  31 ′, and central rod head dome  30   c ′. The adaptor  40 , according to a variant of the present invention, includes one or more adaptor rods  40   a , lock first part  40   b , and lock fastener screw  40   e.    
     As noted, the quantities of elements noted above are in no way limiting the present invention, and there may be other variant of quantities, such as eight ribs  21 . The positions and connections of these assemblies, also with regard to each other, their functions, and methods of operation, will be specified in the following. 
     While the general preference is for a surgical retractor  2 ′ suitable for repeated use, made such that it can be sterilized, sterilization of the components can be avoided by integration of certain single-use components. Examples of possible single-use components are ribs  21  and lighting source  51 . 
       FIG. 3   a  is a top view schematic illustration of a surgical retractor  2 ′, without an adaptor, according to the first embodiment of the present invention, upon which a section plane a-a is marked. 
       FIG. 3   b  is a cross sectional view a-a, isometric top illustration of a surgical retractor  2 ′, according to the first embodiment of the present invention. 
     The section shows the positions of elements relative to each other. Rib  21  is engaged within a slider  15 ′. The cover disc  11 ′ encases the slider  15 ′ and the grooved disc  12  from the outside, and is connected to the channeled disc  13 ′. An angular adjustment bolts  14   a  is engaged with the cover disc  11 ′ and can be in contact with rib  21 . 
       FIG. 4   a  is a top view schematic illustration of a guarding cover  58 ′, according to the first embodiment of the present invention, upon which a section plane b-b is marked. 
     As noted, the guarding cover  58 ′ is meant to prevent the entry of foreign objects, dust, dirt, etc., into the surgical retractor. 
     The guarding cover  58 ′ is shaped as a flat ring, having a guarding ring interior diameter d 1 . This inner diameter must be of a sufficient size to enable passage of the operating tools, as well as to provide the surgeon with a wide enough visual field. The value of this diameter should preferably be no smaller than 50 millimeters. 
       FIG. 4   b  is a side view schematic illustration of the guarding cover  58 ′, according to the first embodiment of the present invention. 
       FIG. 4   c  is a top view schematic illustration of a lighting source supporter  52 , according to the first embodiment of the present invention, upon which a section plane c-c is marked. 
       FIG. 4   d  is an isometric front bottom view schematic illustration of a lighting source supporter  52 , according to the first embodiment of the present invention. 
     The lighting source supporter  52  includes a lighting source supporter base  52   a , which can be shaped as a ring, having a lighting source supporter base ring interior diameter d 2 . 
     This diameter must also be of a sufficient size, similarly to the diameters of other elements to be described in the following, for the same reasons given with regard to the size of guarding ring interior diameter d 1 , (not shown in the present drawings). 
     Surrounding the lighting source supporter base  52   a  is a lighting source supporter wall  52   b  with a walled cylinder shape, on which are lighting source supporter wall slots  52   c , which are meant to prevent disruption of the movement of other elements. 
     The lighting source supporter wall  52   b  in the configuration shown in the present illustrations protrudes slightly above and beneath the lighting source supporter base  52   a , and the part that protrudes beneath has lighting source supporter wall grooves  52   e.    
       FIG. 4   e  is an exploded side view schematic illustration of a lighting assembly  50 ′, according to the first embodiment of the present invention. 
     The lighting assembly  50 ′ shown in the present illustration is composed of the lighting source supporter  52  and lighting source  51 ; however other configurations can also be used, with the lighting assembly  50 ′ being composed of a single unit. 
     The lighting source  51  includes a lighting source base  51   a  and one or more lamps  51   b , which can also be light emitting diode (LED) lights. 
     According to one variant of the present invention, at least one lamp  51   b  is an ultra violet (UV) LED, which provides disinfection during the surgical procedure. 
     The lighting source  51 , if not suitable for repeated sterilization, is a disposable component, meant for single-time use. All other elements must be composed of materials suitable for medical standard repeated sterilization. 
       FIG. 4   f  is an exploded isometric front top view schematic illustration of a lighting assembly  50 ′, according to the first embodiment of the present invention. 
     The lighting source  51  has a lighting source base interior diameter d 4 . The external shape of the lighting source  51  at least partially conforms to the internal shape of the lighting source supporter  52 , so that they are fastened to each other by force of friction, which is no smaller than the weight of each of these elements. 
       FIG. 4   g  is a side view schematic illustration of a lighting assembly  50 ′, according to the first embodiment of the present invention. 
     The present illustration shows the lighting source supporter wall  52   b  and the lighting source supporter base  51   a , engaged with each other. In another possible configuration, the lighting assembly  50 ′ is composed of one unit whose shape is practically identical to that of the engaged units, other than lamps  51   b . The lamps  51   b  are electrically fed from power source  51   c  by means of electricity conductors  51   d.    
     Attached to each lamp  51   b , according to the first embodiment of the present invention, is a light reflector  51   e , shown magnified in circle C, which reflects the light so as to facilitate the surgeon&#39;s good view of the working area, without glaring directly into the surgeon&#39;s eyes. 
       FIG. 4   h  is a cross sectional view b-b illustration of a guarding cover  58 ′ and a cross sectional view c-c illustration of a lighting source supporter  52  according to the first embodiment of the present invention. 
     The top part of the lighting source supporter  52  has a lighting source supporter wall shoulder  52   d , shown magnified in circle A, which has a lighting source supporter wall shoulder outer diameter d 3 . 
     The lighting source supporter wall shoulder outer diameter d 3  and the guarding ring interior diameter d 1  are practically of the same value, so that when the guarding cover  58 ′ is engaged with lighting source supporter  52 , a friction force occurs between them, preventing the guarding cover  58 ′ from separating as a result of gravity or of movement. There are other possible methods of connecting the guarding cover  58 ′ with the lighting source supporter  52 , such as by means of screwing, riveting, etc., and even by means of a fixed connection, when they are composed as a single unit. 
       FIG. 5   a  is an isometric front top view schematic illustration of a cover disc  11 ′, according to the first embodiment of the present invention. 
     The cover disc  11 ′ includes a cover disc base  11   a  having several cover disc base interior threads  11   b  and cover disc base holes  11   g.    
     The presence of the cover disc base holes  11   g  serves the purpose of reducing weight and enables effective penetration of materials such as detergents during rinsing and disinfection. 
     The cover disc base  11   a  is shaped as a flat ring, the internal part of the ring being disposed with cover disc supports  11   f , and its external circumference is mounted within a cover disc wall  11   c.    
     The cover disc wall  11   c  is shaped as a walled cylinder, having cover disc wall holes  11   d , and cover disc wall openings  11   e.    
     The cover disc supports  11   f  protrude into a cover disc perforation  11   i.    
       FIG. 5   b  is a side view schematic illustration of a cover disc  11 ′, according to the first embodiment of the present invention. 
       FIG. 5   c  is an isometric bottom view schematic illustration of a cover disc  11 ′ and lighting source supporter  52 , according to the first embodiment of the present invention. 
     In the configuration shown in the present illustration, the entire cover disc support  11   f  is within lighting source supporter wall  52   b , conforming to a lighting source supporter wall groove  52   e.    
       FIG. 5   d  is an isometric front top view schematic illustration of a cover disc  11 ′, and of lighting source supporter  52 , according to the first embodiment of the present invention. 
     Both elements are engaged in each other, with their shapes and dimensions conforming for the purpose of this engagement. 
       FIG. 6   a  is an isometric front top view schematic illustration of a grooved disc  12 , according to the first embodiment of the present invention. 
     The grooved disc  12  is shaped like a flat ring, with a grooved disc central perforation  12   a  in its center, and a grooved disc outer surface  12   c , some of which comprises grooved disc teeth  12   e . The grooved disc teeth  12   e  serve the purpose of providing the grooved disc  12  with rotational movement. 
       FIG. 6   b  is side view schematic illustration of a grooved disc  12 , according to the first embodiment of the present invention. 
       FIG. 6   c  is bottom view schematic illustration of a grooved disc  12  and a central rod  30 ′, according to the first embodiment of the present invention. 
     This view shows curved grooves  12   b  whose depth, in the present case, is smaller than the thickness of the grooved disc  12 , however can, in other configurations according to the present invention, be for the entire depth of the grooved disc  12 . If the depth of the curved grooves  12   b  is smaller than the thickness of the grooved disc  12 , grooved disc holes  12   d  can be added to facilitate a better flow of disinfectant material through them into the curved grooves  12   b.    
     The grooved disc  12  serves for opening and closing the aperture created by the ribs  21 , (not shown in the present illustration). Each curved groove  12   b  corresponds with one rib  21 , and if all of the curved grooves  12   b  have the same curve shape, the distance of each rib  21  from the grooved disc central perforation center  12   ao  is consistently the same, in every state of rotation of the grooved disc  12 , namely all of the ribs  21 , at every cross section, are on a common circle. 
     According to another variant of the present invention, not all of the curved grooves  12   b  have the same curve shape. The curved grooves  12   b  can have many curve shapes. In the case shown in the present illustration, the curve shape of each one of them is a segment of a circle, having a groove radius r 1 . When viewing the grooved disc  12 , the groove radius origin  12   bo  is not at the same point as the grooved disc central perforation center  12   ao.    
     The grooved disc central perforation center  12   ao  is practically positioned on the central rod tail symmetrical line  30   s.    
     The grooved disc  12  has a grooved disc body  12   f , whose general shape is that of a flat ring, on part of whose circumference are grooved disc teeth  12   e.    
       FIG. 7   a  is side view schematic illustration of a central rod  30 ′, according to the first embodiment of the present invention. 
     The central rod  30 ′ has a central rod tail  30   a′ , having a central rod tail diameter d 17  and in the configuration shown in the present illustration, it is slotted with central rod tail slots  30   b , and has, at its end, central rod head dome  30   c  whose tip is tapered toward its end, from a side view. 
     The slots  30   b  serve the surgeon for the purpose of measuring penetration depth. For example, slots  30   b  can be marked at regular intervals of one centimeter each, and the measure of penetration can then be determined according to the numbers marked outside of the patient&#39;s body. 
     The central rod tail  30   a′  has a central rod tail symmetrical line  30   s . This line is disposed in a fixed location relative to the various components of the surgical retractor, according to the present invention, which do not move relative to each other when the central rod  30 ′ is disposed between the ribs  21 , (not shown in the present illustration), when they are in a closed mode, as they are at the beginning of insertion into the patient&#39;s body. This line can serve as a reference line for measurement of angles and distances, even when the central rod  30 ′ is not in the position presently described. 
     The central rod  30 ′ is designated as the leader guiding the penetration into the body of the operated patient. At the beginning of the procedure, it is centered between the ribs  21  (not shown in the present illustration), which are closed, while the central rod head dome  30   c  protrudes from them, and is first to come into contact with the operated patient&#39;s body. 
     The central rod  30 ′ is taken out and removed from the operated area, after achieving sufficient opening of the ribs  21 . 
       FIG. 7   b  is bottom view schematic illustration of a central rod head dome  30   c , according to the first embodiment of the present invention. 
     In the configuration shown in the present invention, from a bottom view, the central rod head dome  30   c  has an oval shape; however it can have other shapes as well. 
       FIG. 8   a  is an isometric front top view schematic illustration of a channeled disc  13 ′, according to the first embodiment of the present invention. 
     The channeled disc  13 ′ includes a channeled disc base  13   a , which has at its circumference the channeled disc wall  13   b , which has several channeled disc wall niche  13   c , as well as channeled disc wall tenons  13   m.    
     This shape of the circumference of the channeled disc  13 ′ serves the purpose of conforming to other component at the time of assembly; however other shapes can also be used according to the present invention. Furthermore, for the purpose of connecting components, there are several channeled disc wall holes  13   d , having internal screw threading. 
       FIG. 8   b  is side view schematic illustration of a channeled disc  13 ′, according to the first embodiment of the present invention. 
       FIG. 8   c  is bottom view schematic illustration of a channeled disc  13 ′, according to the first embodiment of the present invention, upon which a section plane d-d is marked. 
     In the center of the channeled disc  13  is channeled disc perforation  13   e , which is shaped as a circle having channeled disc perforation radius r 2 . The channeled disc perforation radius r 2  disc is likely to be the element most limiting the maximal visual field of view that can be achieved during an operation, and the element most limiting the dimensions of the operating tools, therefore its size should preferably be no smaller than 15 millimeters. 
     The channeled disc  13 ′ is slotted for its entire depth with channeled disc long slots  13   f  in order to enable positioning and movement of the ribs  21 , (not shown in the present illustration), and in the channeled disc short slots  13   g , which create cavities for the positioning of the lamps  51   b , (not shown in the present illustration). 
       FIG. 8   d  is cross sectional view d-d illustration of a track  13   h , according to the first embodiment of the present invention. 
     The channeled disc  13 ′ also engages a component that can make radial linear movement relative to a single point, the slider  15 ′, (which, along with other elements mentioned in the description of the present illustration, is not shown in the present illustration). For this purpose, the channeled disc  13 ′ has tracks  13   h . Every track  13   h  is closed on its bottom, in view of the orientation of the present illustration, by the channeled disc base  13   a , on both of its sides by two track side walls  13   i , and on its top by track upper wall  13   j.    
     The track upper wall  13   j  has a channel upper opening  13   l , which has suitable dimension for longitudinal movement of the slider upper body  15   b . The space created between the elements described, as shown in the present illustration, comprises the channel  13   k , whose dimensions are suitable for those of a slider  15 ′ so as to enable its radial longitudinal movement, and to prevent its movement in any other undesired direction. 
       FIG. 9   a  is an isometric front top view schematic illustration of casing  70 ′, according to the first embodiment of the present invention. 
       FIG. 9   b  is a side view schematic illustration of casing  70 ′, according to the first embodiment of the present invention. 
       FIG. 9   c  is an exploded side view schematic illustration of casing  70 ′, according to the first embodiment of the present invention. 
     According to the variant shown in the present illustration, the engagement of the cover disc  11 ′ with the channeled disc  13 ′ is done by means of geometrically conforming both to each other, together forming a casing  70 ′ suitable for carrying grooved disc  12 , (not shown in the present illustration), and granting it smooth rotational movement, as well as for carrying and granting smooth movement of other components. The present illustration shows that the cover disc wall  11   c  and the cover disc wall hole  11   d  respectively conform with the channeled disc wall niche  13   c  and the channeled disc wall hole  13   d , thus enabling a successful connection of the cover disc  11 ′ with the channeled disc  13 ′. 
       FIG. 9   d  is a side view schematic illustration of a casing bolt  70   a , according to the first embodiment of the present invention. 
     Casing bolt  70   a , one of which is shown in the present illustration magnified relative to the previous illustration, completes the connection of the cover disc  11 ′ together with the channeled disc  13 ′. 
       FIG. 10   a  is an isometric side top view schematic illustration of a rib  21  and a slider  15 ′ combined together, according to the first embodiment of the present invention. 
     All the ribs  21  and sliders  15 ′ are arranged in engaged pairs. Every slider  15 ′ is designated to linearly move one of the ribs  21 . 
     Rib  21  has a rib back surface  21   b  and a rib front surface  21   f . The rib front surfaces  21   f  of all the ribs  21  all face inwards relative to the spatial shape that they form together. 
     The rib back surface  21   b  and a rib front surface  21   f  are each divisible into several segments according to the structural parts of the type of rib  21  to which they belong. 
       FIG. 10   b  is an exploded isometric side top view schematic illustration of a slider  15 ′, according to the first embodiment of the present invention. 
     The slider  15 ′ includes a slider main body  15   a , whose shape and dimensions are suitable for maintaining back and forth linear movement within a channel  13   k , (not shown in the present illustration). 
     From the top part of the slider main body  15   a , protrudes slider upper body  15   b , whose shape and dimensions are suitable for maintaining back and forth linear movement within a channel upper opening  13   l , (not shown in the present illustration). 
     Above slider upper body  15   b , protrudes a slider pin  15   i , whose shape and dimensions are suitable for maintaining back and forth linear movement within curved groove  12   b , (not shown in the present illustration). 
     The slider pin  15   i  can be an integral part of the slider upper body  15   b  and of the slider main body  15   a , or can be partially engaged within slider pin hole  15   c.    
     The part of slider  15 ′ designated to be engaged with rib  21 , (not shown in the present illustration), has two slider arms  15   d , the space between which is suitable to contain a rib  21 , so as to enable it rotational movement while preventing its lateral movement. Between both arms  15   d  is a slider pivot  15   j , within two slider pivot holes  15   e.    
     At the bottom of the slider main body  15   a , near the end farther from the slider arms  15   d , is an optional slider niche  15   g , within which is a slider friction reducer  15   h  that protrudes very slightly relative to the dimensions of the slider  15 ′, from beneath the slider  15 ′. The slider friction reducer  15   h  is composed of a material, such as silicone, having a smaller friction coefficient than the friction coefficient of the material, for example steel, composing the slider  15 ′. 
       FIG. 10   c  is a top view schematic illustration of a slider main body  15   a , according to the first embodiment of the present invention, upon which a section plane e-e is marked. 
     Between both slider arms  15   d , is a perpendicularly disposed slider among arms surface  15   f . The present illustration shows a view from the top of the slider among arms surface  15   f . Between both of the slider arms  15   d , is a slider arms gap d 14 . 
       FIG. 10   d  is a cross sectional view e-e illustration of a slider main body  15   a , according to the first embodiment of the present invention. 
     The present illustration indicates three dimensions of special significance for the purpose of conforming with a rib  21 , (not shown in the present illustration), which are a slider pivot hole diameter d 5 , a gap between the slider pivot and the slider among arms surface d 6  and a slider among arms surface radius r 3 . 
       FIG. 10   e  is a partial side view schematic illustration of a rib  21 , according to the first embodiment of the present invention. 
     The present illustration shows details and dimensions of special significance for the purpose of conforming with slider  15 ′, (not shown in the present illustration). A concave segment of a rib front surface  21   a  serves to transmit force during opening movement of rib  21  from the slider pivot  15   j , (not shown in the present illustration). The preferred shape of concave segment of a rib front surface  21   a  is a half circle whose center is defined as a concave segment of a rib front surface origin  21   o , having a concave segment of a rib front surface diameter d 7    
     The convex segment of a rib back surface  21   c  has a section shape of a circle, whose center is concave segment of a rib front surface origin  21   o , and which has a convex segment of a rib back surface radius r 4 . 
     The maximum value of the convex segment of a rib back surface radius r 4  is at most equal to the value of the gap between the slider pivot and the slider among arms surface d 6 , (not shown in the present illustration), so as to enable replacement of rib  21 . 
     A rib shoulder  21   d  serves to transmit force from the slider main body  15   a , (not shown in the present illustration), in order to perform closing. Part of rib shoulder  21   d  has a rib shoulder concave segment  21   e , having a rib shoulder concave segment radius r 5 . 
     The value of the rib shoulder concave segment radius r 5  corresponds with the slider among arms surface radius r 3 , (not shown in the present illustration). 
       FIG. 10   f  is a partial side view schematic illustration of a rib  21  and a slider  15 ′ partially sectioned, according to the first embodiment of the present invention. 
     The present illustration shows a state of movement toward opening  15   op , in which the slider pivot  15   j  is moving to the right, in the orientation shown in the present illustration, and applies force to rib  21  in the area of contact with the concave segment of a rib front surface  21   a.    
       FIG. 10   g  is a partial side view schematic illustration of a rib  21  and a slider  15 ′ partially sectioned, according to the first embodiment of the present invention. 
     The present illustration shows a state of movement toward closing  15   cl , in which slider  15 ′ moves to the left, in the orientation shown in the present illustration, and applies force, to rib  21  in the area of contact with the slider among arms surface  15   f , which acts on the rib shoulder  21   d . The rib shoulder  21   d , also limits the rotational movement of rib  21  clockwise, according to the view shown in the present illustration, prevention of the rotational movement occurs during contact between the rib shoulder  21   d  with the slider among arms surface  15   f.    
       FIG. 10   h  is a side view schematic illustration of a rib  21 , an angular adjustment bolt  14   a  and a slider  15 ′, partially sectioned, according to the first embodiment of the present invention. 
     The present illustration describes forces affecting rib  21  when it is inside the operated patient&#39;s body when body tissue  90  applies pressure to it, the resultant force of which, the body tissue force F 2 , is applied to a specific point on a rib working arm  21   wa  of the rib  21 . Conversely, in the state shown in the present illustration, the angular adjustment bolts  14   a  applies adjustment bolt force F 1  on a rib force arm  21   fa . Both the adjustment bolt force F 1  and the body tissue force F 2  are balanced by a slider pivot force F 3 , which is applied in the opposite direction. 
     The concave segment of a rib front surface origin  21   o  comprises a possible rotational center for rib  21 , and its location determines which part of the rib  21  acts as the rib working arm  21   wa  and which acts as the rib force arm  21   fa.    
     Furthermore, when the angular adjustment bolts  14   a  applies adjustment bolt force F 1  to the rib force arm  21   fa , rib  21  rotates counterclockwise, in the view shown in the present illustration, and a gap is formed between the rib shoulder concave segment  21   e  and the slider among arms surface  15   f.    
     The rib force arm  21   fa  has a rib force arm length d 8  and the rib working arm  21   wa  has a rib working arm length d 9 . 
       FIG. 10   i  is a side view schematic illustration of a slider  15 ′, according to the first embodiment of the present invention. 
     When the slider  15 ′ moves toward opening, to the right in the orientation of the present illustration, angle α is formed between the slider and the channeled disc and the contact between slider  15 ′ with the surface upon which it moves is only in the area of the slider friction reducer  15   h.    
       FIG. 11  is a side view schematic illustration of a rib  21 , an angular adjustment bolt  14   a  and a slider  15 ′, partially sectioned, in six stages of separation, according to the first embodiment of the present invention. 
     These stages are part of a method for replacing rib  21 , and they demonstrate the manner of removing rib  21  from its place, from a state suitable for operation, engaged with slider  15 ′. Similarly, but with reversal of the order of stages, rib  21  is engaged with a slider  15 ′. 
     The stages are: 
     Starting, showing one possible starting state, in which the angular adjustment bolt  14   a  is in contact with rib  21  (stage A); 
     retreating of the angular adjustment bolt  14   a  (stage B); 
     rotating clockwise of the rib  21  (stage C); 
     pulling up the rib  21  as much as possible (stage D) 
     rotating counter-clockwise of the rib  21  (stage E); and
         separating the rib  21  from the slider  15 ′ by pulling up the rib  21  all the way out (stage F).       

     In order to enable this removal there cannot be any width dimension of rib  21 , required to go through the gap between the slider pivot and the slider among arms surface d 6 , which is wider than this gap. 
       FIG. 12   a  is a side view schematic illustration of a rib  21 , according to the first embodiment of the present invention. 
     The present illustration shows the division of the rib  21  into two arms. In a state in which the concave segment of a rib front surface  21   a  practically serves as a support point and both ends, the rib bottom end  21   h  and the rib top end  21   g , are subject to forces F, which are horizontal according to the orientation of the present illustration; the part of rib  21  in which there is a counterclockwise twisting effort is defined as rib force arm  21   fa  and the part in which there is a clockwise twisting effort is defined as rib working arm  21   wa.    
     Close to the rib bottom end  21   h , there is a rib bottom end projection  21   i , which is designated to facilitate prevention of rib  21  being pushed outward and upward as a result of forces applied to it by the operated patient&#39;s body tissue. 
       FIG. 12   b  is a side view schematic illustration of a rib  21 , according to the first embodiment of the present invention. 
     The present illustration defines additional features of rib  21 . Rib  21 , according to the present invention, is practically rigid, considering the forces that may be applied to it during performance of an operation on a human body. The term “rigid” is to indicate that the rib practically does not bend, or deflect, when a reasonable force, moment, or torque from the tissue is applied. Proper design and production of rib  21  with use of suitable materials such as steel or titanium, can ensure meeting the required test criterion for a rib  21  having a rib working arm length d 9  and a maximum rib bottom end deflection d 13 , under the activation of test force F 4  at a predefined level on the rib bottom end  21   h , with the rib force arm  21   fa  harnessed. 
     A practical example of such a test is the following data: 
     rib working arm length d 9 : 60 centimeter; 
     test force F 4 : 200 Newton; and 
     maximum rib bottom end deflection d 13 : 0.4 millimeter. 
     One effective way of obtaining the required rigidity, without adding unnecessary weight, is by selecting a shape in which rib working arm  21   wa  has a rib working arm width d 12  having a size that tapers toward the rib bottom end  21   h.    
     Similarly to rib force arm  21   fa , there is a rib force arm width d 11 , which tapers toward rib top end  21   g.    
     Another feature is the rib working arm projection to the center d 10 , which is designated to remove the rib force arm  21   fa  from the doctor&#39;s visual field. The value of the rib working arm projection to the center d 10  should preferably be at least 10 millimeters, when this distance is measured from the concave segment of a rib front surface origin  21   o , perpendicular to the plane on which rib working arm front surface  21   k  is disposed. 
       FIG. 12   c  is a side view schematic illustration of two ribs  21 , according to the first embodiment of the present invention. 
     The two ribs  21  in the present case are on the same plane and are shown as mirror images of each other. 
     Rib  21  has a rib force arm front surface  21   j  and a rib working arm front surface  21   k , which are for most of their lengths in side view, straight. The present illustration shows each one of both ribs  21  at a rib opening angle δ at which the rib force arm front surface  21   j  is parallel to a symmetry line between both ribs  21 . In this state, the angle between the rib force arm front surface and the rib working arm front surface β is equal to rib opening angle δ. 
     The rib opening angle δ is measured between the symmetrical line  30   s  and the rib working arm front surface  21   k.    
       FIG. 13   a  is a side view schematic illustration of a rib  21 , according to the first embodiment of the present invention, upon which a section plane f-f is marked. 
       FIG. 13   b  is a cross sectional view f-f, view illustration of a rib  21 , according to the first embodiment of the present invention. 
     Rib  21  has a rib thickness d 16 , which conforms to the dimensions of the slider arms gap d 14 , so as to enable rotational movement between the two, but to enable practically no sideways movement of rib  21 . The side of the section facing forwards is tapered, and has a rib cross section head angle γ, a preferred value of which is 360 degrees divided by the number of ribs  21  included in the retractor. The tapered part end is cut off, and has a rib cross section head cut off length d 15 . 
       FIG. 13   c  is six cross sectional views f-f illustration of six ribs  21 , according to the first embodiment of the present invention. 
     According to a variant of the present invention the retractor includes six ribs  21 , however other numbers can be used. 
     The ribs  21  are shown in the present illustration in a state referred to in the present invention as a closed state, and each one touches the adjacent ones for most of its length rib working arm  21   wa , (not shown in the present illustration). In this closed state, the ribs  21  bind an internal circle (dashed line in the illustration), having a ribs interior diameter d 18 , which conforms to the dimensions of the central rod tail diameter d 17 . 
       FIG. 14   a  is a side view schematic illustration of a rib  21 , according to the first embodiment of the present invention. 
     According to a variant of the present invention, the rib  21  includes a rib hole  21   m . The rib hole  21   m  is assembled such that a slider pivot  15   j , (not shown in the present illustration), is engaged within it, and their dimensions conform so as to enable effective rotational movement between both. 
     According to this variant, replacement of a rib  21  requires removing and then reinserting the slider pivot  15   j , (not shown in the present illustration), in place. 
       FIG. 14   b  is a side view schematic illustration of a rib  21  with a rib hook  21   n , according to the first embodiment of the present invention. 
     In order to prevent penetration of the patient&#39;s skin into the wound cavity, the rib  21 , according to a variant of the present invention, is equipped with a rib hook  21   n . In order to prevent the addition of the rib hook  21   n  from hampering the replacement of rib  21 , the rib hook  21   n  must either be sufficiently small, detachable from the rib  21 , or foldable, for example around rib hook pin  21   p , in this case, the rotation ability is upward, in the orientation shown in the present illustration, while downward rotation is not possible beyond the state shown in the illustration. 
       FIG. 14   c  is a side view schematic illustration of a rib  21 , according to the first embodiment of the present invention. 
     According to a variant of the present invention, the rib  21  is somewhat flexible, and does not need to meet the definition and test requirement for rigidity given with regard to the description of  FIG. 12   b . As such, the rib working arm length d 9  can have a relatively high value, and there is no requirement for any large change in values of rib working arm width d 12  according to their positions along the rib working arm  21   wa , to the extent that their values can be fixed. 
       FIG. 14   d  is an isometric view schematic illustration of six ribs  21 , and a flexible sleeve  23 , according to the first embodiment of the present invention. 
     The flexible sleeve  23  externally encases the six ribs  21  along their rib working arms  21   wa , for their entire length or part of it, and is designated to prevent tissue from entering the opening created for the purpose of performing the medical procedure. 
     The material composing the flexible sleeve  23  can be polyisoprene, a natural polymer, for example, however this material is in no way limiting the present invention. 
     Polyisoprene is strong and elastic, is transparent after expansion, is inert, and does not cause allergic reactions. 
       FIG. 14   e  is a side view schematic illustration of rib  21 , having rib segments  21   q , in a relaxed state, according to the first embodiment of the present invention. 
     The rib working arm  21   wa  of the rib  21  is divided into several rib segments  21   q , three in the case of the present illustration. 
     A cable  21   s  is connected at one end to an anchoring point  21   t , disposed within the lower rib segment  21   q.    
     The cable  21   s  is shown in the present illustration as if running through a series of perforations for the length of all parts of a transparent rib  21  and connects at the other end to a cable tensioner  21   r . When the cable tensioner  21   r  is in a proper state, the cable  21   s  is relaxed and enables minimal distancing of the rib segments  21   q  from each other, thus enabling creation of a rotational angle in any direction, if there is no specific device to limit it, between every pair of adjacent rib segments  21   q . Even though the present illustration shows only one cable  21   s  and only one cable tensioner  21   r , this is in no way limiting the present invention, and different quantities of these elements are also possible. 
       FIG. 14   f  is a side view schematic illustration of rib  21 , having rib segments  21   q , in a flexed state, according to the first embodiment of the present invention. 
     The cable tensioner  21   r  applies tensioning force on the cable  21   s , thus causing the rib segments  21   q  to join so as to create the desired external shape of rib  21 . 
     The cable  21   s  must be composed of a sufficiently strong material such as carbon nanotubes. 
       FIG. 14   g  is an isometric view schematic illustration of a rib  21 , having rib segments  21   q , in a flexed state, according to the first embodiment of the present invention. 
       FIG. 14   h  is an isometric view schematic illustration of rib  21 , having rib segments  21   q , in a relaxed state, according to the first embodiment of the present invention, with the rib segments  21   q  distanced from each other. 
     The distances between the rib segments  21   q  shown in the present illustration are exaggerated, for the purpose of demonstrating the upper part of each rib segment  21   q , which is one of many possible shapes enabling partial engagement of each rib segment  21   q  in the lower part of the rib segments  21   q  above it. The present invention is not limited to any specific number of rib segments  21   q , or any specific position of them. 
       FIG. 15   a  is an isometric top view schematic illustration of a transmission  17 ′, partially exploded, according to the first embodiment of the present invention. 
     The transmission  17 ′ is designated to grant rotational movement to grooved disc  12 . The movement starts with manual rotation of at least one of the two transmission knobs  17   a , which transmit rotational movement through a transmission tubular  17   e  to a transmission shaft  17   b′ , and through that to a transmission worm  17   c . The transmission worm  17   c  rotates a transmission first cog wheel  17   f ′, which is rigidly connected on a shaft with a transmission second cog wheel  17   g . The transmission second cog wheel  17   g  rotates a transmission third cog wheel  17   h , which, at the end of the process, grants the necessary rotational movement to grooved disc  12  by means of the grooved disc teeth  12   e . The engagement of the transmission first cog wheel  17   f ′ by rigid connection on a shaft with the transmission second cog wheel  17   g  is for the purpose of obtaining the desired transmission ratio, and to provide a convenient distance for users&#39; hands when forming the opening operation. 
     Use of the transmission third cog wheel  17   h , other than its effect on the transmission ratio, is to distance the transmission knobs  17   a  from the grooved disc  12 . 
       FIG. 15   b  is an isometric bottom view schematic illustration of a transmission  17 ′, partially exploded, according to the first embodiment of the present invention. 
     This transmission can enable controlled opening at a slow rate of 50 micrometers per second by applying force of the fingers. 
     According to the present invention, transmission systems of various different structures can be used. Likewise, a suitable mechanical engine can be used instead of manual force. 
       FIG. 16   a  is a top view schematic illustration of a carrier  16 , according to the first embodiment of the present invention. 
     The carrier  16  includes a carrier bow  16   a , a carrier bridge  16   c , two carrier arms  16   f , and a carrier back wall  16   g.    
     The carrier  16  connects the channeled disc  13 ′ with the adaptor  40 , (both not shown in the present illustration), and carries the transmission  17 ′, (not shown in the present illustration). 
     Carrier bow  16   a  has carrier bow bottom holes  16   b  and carrier bow side holes  16   i  (not shown in the present illustration), for the purpose of connection to the channeled disc  13 ′, (not shown in the present illustration). 
     In the carrier bridge  16   c  there are two holes, a carrier bridge first hole  16   d , designated to carry the shaft of the transmission third cog wheel  17   h , (not shown in the present illustration), and a carrier bridge second hole  16   e , designated to carry the common shaft of the transmission first cog wheel  17   f′  and the transmission second cog wheel  17   g , (both not shown in the present illustration). 
       FIG. 16   b  is a back view schematic illustration of a carrier  16 , according to the first embodiment of the present invention. 
     Carrier back wall holes  16   h  in the carrier back wall  16   g  are designated for connection to the adaptor rods  40   a , (not shown in the present illustration). 
       FIG. 16   c  is a side view schematic illustration of a carrier  16 , according to the first embodiment of the present invention. 
     The transmission shaft  17   b′ , (not shown in the present illustration), in an assembled state, runs through carrier arm hole  16   j  in the two carrier arms  16   f.    
       FIG. 16   d  is an isometric top view schematic illustration of a carrier  16 , and a transmission  17 ′, according to the first embodiment of the present invention. 
     One transmission knob  17   a  is not shown in the present illustration. The transmission worm  17   c  is mounted upon the transmission shaft  17   b′ , between both carrier arms  16   f.    
     The transmission first cog wheel  17   f′ , the transmission second cog wheel  17   g  and the transmission third cog wheel  17   h  are mounted above the carrier bridge  16   c , according to the orientation of the present illustration. 
       FIG. 16   e  is an isometric bottom view schematic illustration of a carrier  16 , and a channeled disc  13 ′, according to the first embodiment of the present invention. 
     Their joint connection can be by means of screws through the carrier bow bottom holes  16   b  and the carrier bow side holes  16   i . The screws can be such as the casing bolts  70   a , (not shown in the present illustration), with suitable holes, having internal screw threading in the channeled disc base  13   a  and the channeled disc wall  13   b.    
       FIG. 17   a  is an isometric side top view schematic illustration of a carrier  16 , and an adaptor  40 , according to the first embodiment of the present invention. 
       FIG. 17   b  is an exploded isometric top view schematic illustration of a carrier  16 , and an adaptor  40 , according to the first embodiment of the present invention. 
       FIG. 18   a  is an isometric side top view schematic illustration of six ribs  21  in a closed state, according to the first embodiment of the present invention. 
     The number of ribs  21  shown in the present illustration is six, however this is not limiting the present illustration specifically to this number. In this state, the ribs  21  are inserted into the operated patient&#39;s body, while they are as tightly close to each other as possible, thus creating an entry puncture of the smallest diameter that can be achieved with them. This diameter, which is determined by the widest section created by the six ribs  21 , should preferably be no larger than 8 mm, while in any case the diameter should be as small as it enabled by the mechanical strength of the ribs  21 . 
     The arrows at the upper part of the present illustration indicate movement directions  21   md  of each one of the ribs  21 , if linear opening is required. 
       FIG. 18   b  is an isometric side top view schematic illustration of six ribs  21  in an open state, according to the first embodiment of the present invention. 
     The opening performed in order to achieve this state was with uniform linear movement of each one of the six ribs  21 , such that all six are, at every possible lateral section, on a circle together. 
       FIG. 18   c  is an isometric side top view schematic illustration of six ribs  21  in a closed state, according to the first embodiment of the present invention. 
     The arrows at the lower part of the illustration indicate the possibility of rotational movement  21   rm  of ribs  21 , two in this case. 
       FIG. 18   d  is an isometric side top view schematic illustration of six ribs  21  in an open state, according to the first embodiment of the present invention. 
     This state was achieved after performance of rotational movement in opposite directions and equal distance of two ribs  21 . 
       FIG. 18   e  is an isometric side top view schematic illustration of six ribs  21  in an open state, according to the first embodiment of the present invention. 
     This state was achieved after performance of uniform linear opening of all six ribs  21 , followed by rotational movement in opposite directions and equal distance of two ribs  21 , both on the same plane of movement. 
       FIG. 18   f  is a bottom view schematic illustration of six ribs  21  in an open state, according to the first embodiment of the present invention. 
     This state was achieved after performance of uniform linear opening of all six ribs  21 , followed by rotational movement in opposite directions and equal distance of two ribs  21 , both on the same plane of movement. 
     The six ribs  21 , at each lateral section, are all on an ellipse. 
       FIG. 19   a  is a bottom view schematic illustration of a grooved disc  12 , and six sliders  15 ′, in closed state, according to the first embodiment of the present invention. 
     In the closed state of the present illustration, all six of the slider pivots  15   j  are each on a curved groove  12   b  designated for it, in a location in which the slider pins&#39; distance from the grooved disc central perforation center d 19 (μ) is minimal. 
       FIG. 19   b  is a bottom view schematic illustration of a grooved disc  12 , and six sliders  15 ′, in opened state, according to the first embodiment of the present invention. 
     After the grooved disc  12  performs rotational movement of a grooved disc rotational angle μ, the slider pins&#39; distance from the grooved disc central perforation center d 19 (μ) is maximum. Between both of these end states, the slider pins&#39; distance from the grooved disc central perforation center d 19 (μ) depends on the grooved disc rotational angle μ. 
     The movement performed by each one of the six sliders  15 ′ is a radial linear movement. 
     As used herein the specifications and claims sections, the terms radial linear movement, linear movement, radial movement, and the like, all refers to movements causing rib  21  to move along a straight line going through the grooved disc central perforation center  12   ao.    
       FIG. 20  is a side view schematic illustration of a rib  21  having sensors, and a block diagram of transducers, according to the first embodiment of the present invention. 
     For the purpose of pressure and saturation measurement monitoring during the operation, at least one rib  21  is mounted with a pressure sensor  80   a  and a tissue oxygen saturation sensor  80   b , disposed near the rib back surface  21   b , and each connected to an electrical conductor  80   d . The pressure sensor  80   a  transmits signals to a pressure transducer  80   e , and the tissue oxygen saturation sensor  80   b  transmits signals to an oxygen saturation sensor  80   f.    
     The pressure sensor  80   a  serves the purpose of measuring pressure according to the type of tissue applying the pressure, such as intra-cranial pressure, intra-tissue pressure, or retracted tissue pressure 
     The tissue oxygen saturation sensor  80   b  can also be composed of an infrared diode emitter that emits infrared radiation and a receiver for receiving the infrared radiation returned from the tissue. 
     The infrared diode emitter and the receiver are disposed behind a transparent window  80   c , which can also be made of ceramic material or glass. 
     According to anther variant of the present invention the pressure sensor  80   a  and the tissue oxygen saturation sensor  80   b  are mounted separately, each on a different rib  21 . 
       FIG. 21  is a side view schematic illustration of a surgical retractor  2 , after insertion and opening for the purpose of performing spinal minimal invasive neurosurgery, according to the embodiments of the present invention. Even though the present illustration includes a surgical retractor  2 ′ of the first embodiment of the present invention, the action described here can also be performed with the surgical retractors  2 ″,  2 ′″ of the second and third embodiment of the present invention. This also applies to the following illustrations, through  FIG. 27   f.    
     The ribs  21  were inserted through the muscle  90   a  and opened, in the case shown in the present illustration, with the opening movements of all of the ribs  21  being strictly linear. 
     The insertion was toward the vertebrae  90   c , more specifically toward the spinal canal  90   c . Subsequently, an incision line of lamina  90   d  was made. Due to the external shape of the bone  90   e , use was made of ribs  21  of varying lengths, with the rib  21  shown as the central one being longer. 
     A wedge  91 , shown here magnified relative to the dimensions of the surgical retractor  2 ′, can serve for opening-distraction and fusion of lamina vertebralis. 
       FIG. 22  is a side view schematic illustration of two surgical retractors  2 ′ after insertion and opening, for the purpose of performing spinal minimal invasive neurosurgery, according to the first embodiment of the present invention. 
     During performance of the operation, use was made of two surgical retractors  2 ′ and two incision lines of lamina  90   d  are made. 
     When necessary, one retractor can be used to perform an operation on one side and, after completion on one side, to perform the same operation on the other side. However, it is optimally preferable to perform a simultaneous bilateral laminotomy (SBL) with minimal time delay, to prevent future anatomical asymmetry in lamina and any unnecessary movement of the excised lamina, which can cause iatrogenic damage to neural roots and ligaments. Likewise, simultaneous insertion of bilateral wedges for symmetric spinal channel decompression (SSCD) is also preferable. 
     The present illustration clearly shows the different lengths of ribs  21  relative to each other. 
       FIG. 23  is a side view schematic illustration of a rib  21 , having a rib hook  21   n , inside skin and muscle, according to the first embodiment of the present invention. 
     The present illustration demonstrates the manner in which the rib hook  21   n  supports skin  90   f  and is above fascia  92 , while the muscles  90   a  are in contact with rib  21 . 
       FIG. 24  is a side view schematic illustration of a surgical retractor  2 ′ at three different angles, according to the first embodiment of the present invention. 
     This illustration demonstrates the option of inserting a surgical retractor  2 ′ through one single incision and positioning it at different angles relative to the spine for the purpose of performing several different operations. Between subsequent operations, the ribs  21  can be replaced to be of a suitable length for each different purpose. 
       FIG. 25  is a side view schematic illustration of a surgical retractor  2 ′ at two different angles, according to the first embodiment of the present invention. 
     According to a variant of the present invention, the ribs  21  are curved. This illustration demonstrates the option for performing bilateral spinal cord decompression via a single incision. 
       FIG. 26  is an isometric view schematic illustration of a surgical retractor  2 ′ connected to holding arms  48 , according to the first embodiment of the present invention. 
     The present illustration demonstrates connection and carrying of the surgical retractor  2 ′ without use of an adaptor  40 , (not shown in the present illustration). 
     The surgical retractor  2 ′ according to a variant of the present invention includes cover disc holding pins  11   j , for example, three, each of which can be connected to a holding arm  48 , with a clamp  47 , or any other suitable device, at its end, for the purpose of connection to the operation bed. 
     The holding arm  48  is an arm which can be bent and geometrically adapted, and is capable of steadily carrying a load. This arm can be continuous or composed of segments. 
       FIGS. 27   a - 27   f  are side view schematic illustrations of a surgical retractor  2 ′ at six different stages of opening in the operated patient&#39;s body, according to the first embodiment of the present invention. 
     All six illustrations show only two ribs  21  for each retractor  2 ′. 
       FIG. 27   a  shows a stage of insertion of a retractor  2 ′, having ribs  21 , with the length of each one being different from the other. 
     These lengths are selected according to the anatomic structure of the operated patient. 
       FIG. 27   b  shows a stage of linear opening, toward the left according to the orientation of the present illustration, of the longer rib  21 . 
       FIG. 27   c  shows a stage of angular opening, clockwise according to the orientation of the present illustration, of the longer rib  21 . 
       FIG. 27   d  shows a stage of angular opening, counterclockwise according to the orientation of the present illustration, of the shorter rib  21 . 
       FIG. 27   e  shows a stage after replacement of the shorter rib  21  with a longer rib  21 , which requires removal and subsequent reinsertion of the retractor  2 . 
       FIG. 27   f  shows an additional stage of angular opening, counterclockwise according to the orientation of the present illustration, of the new rib  21 . 
     It is important to note that these stages, as shown above are not in any way limiting the present invention, and opening can be performed in many various forms and stages. 
       FIG. 28  is a flow chart that schematically illustrates a method of operation for minimal invasive (MI), bilateral symmetric decompression (BSD) of spinal stenosis (SS), in accordance with the embodiments of the present invention. 
     In the first stage of the method of operation for decompression of spinal stenosis, a surgical retractor is inserted through the bilateral projection of lamina vertebralis, wherein the surgical retractor has ribs and a mechanism for transferring of linear and rotational movements of the ribs, (stage  201 ). 
     In the second stage of the method of operation for decompression of spinal stenosis, the ribs are moving in linear movements, (stage  202 ). 
     In the third stage of the method of operation for decompression of spinal stenosis at least one rib is moving in a rotational movement, (stage  203 ). 
     In the fourth stage of the method of operation for decompression of spinal stenosis an incising a lamina proximal to vertebral facets is done with a micro drill or circular micro saw, (stage  204 ). 
     In the fifth stage of the method of operation for decompression of spinal stenosis a wedge is inserting for a distraction of bilateral vertebral lamina, (stage  205 ). 
       FIG. 29   a  is an isometric front top view schematic illustration of a surgical retractor  2 ″ according to a second embodiment of the present invention. 
     This embodiment is simpler than the first embodiment. It includes less part, can be more lightweight, and can likewise be less expensive. As such, it can be suitable for single-time use, as a whole or the majority of its parts. 
     This embodiment includes the same ribs  21 , for all features, as described so far according to the present invention. The ribs  21  of all the embodiments can be made of material or materials transparent to x-rays. 
     The channeled disc  13 ″ and the slider  15 ″ of the surgical retractor  2 ″ according to second embodiment differ in shape from the channeled disc  13 ″ and the slider  15 ″ of the surgical retractor  2 ′ according to first embodiment. However, in both embodiments, the sliders  15 ′,  15 ″ are assembled into channeled discs  13 ′,  13 ″ so as to enable linear radial movement relative to the centers channeled discs  13 ′,  13 ″. 
       FIG. 29   b  is a side view schematic illustration of a surgical retractor  2 ″, according to the second embodiment of the present invention. 
     The present illustration shows ribs  21  that are all identical in shapes and dimensions, in a state following angular opening. Channeled disc  13 ″ is attached to a base disc  18 , under which the illustration shows lamps  51   b.    
       FIG. 30  is an exploded, isometric front top view schematic illustration of a surgical retractor  2 ″, according to the second embodiment of the present invention. 
     The surgical retractor  2 ″, according to the second embodiment, includes several assemblies, the mechanism for transferring of linear and rotational movements  10 ″, the ribs assembly  20 , and the lighting assembly  50 ″. 
     The mechanism for transferring of linear and rotational movements  10 ″ includes the sliders  15 ″, slider pivots  15   j , angular adjustment bolts  14   a , linear adjustment bolts  14   b , channeled disc  13 ″, and a base disc  18 . 
     The channeled disc  13 ″ can be made of various materials, also including various metals or materials transparent to x-rays, such as a plastic material, and it can be designated for single-time use. 
     The base disc  18  is connected to the bottom of the channeled disc  13 ″ and serves as a cover for electric wires (not shown in the present illustration), which provide electrical power supply to lighting assembly  50 ″, and can also be made of various materials, also including various metals or materials transparent to x-rays. 
     Each rib  21  engages with a slider  15 ″ by means of a replaceable slider pivot  15   j  and can be made of various materials, also including various metals or materials transparent to x-rays. 
     Slider  15 ″ includes a slider first interior thread  15   m  into which is screwed an angular adjustment bolt  14   a , and a slider second interior thread  15   n  into which is screwed a linear adjustment bolt  14   b , by means of which the linear and angular opening of the ribs  21  can be adjusted. 
       FIG. 31   a  is a side view schematic illustration of a segment of a channeled disc  13 ″, an angular adjustment bolt  14   a , a linear adjustment bolt  14   b , a slider  15 ″, a slider pivot  15   j , and a rib  21  of the surgical retractor  2 ″, according to the second embodiment of the present invention. 
     The screwing of the angular adjustment bolt  14   a  into the slider first interior thread  15   m  (not shown in the present drawing), of the slider  15 ″ applies moment on the rib  21 , resulting in its rotational movement around the slider pivot  15   j  relative to the slider  15 ″. Screwing the linear adjustment bolt  14   b  into the slider second interior thread  15   n  (not shown in the present drawing), of the slider  15 ″ applies force to the channeled disc  13 ″ resulting in linear movement of the slider  15 ″ along with the rib  21  relative to the channeled disc  13 ″. 
     The shapes and sizes of the slider pivot hole  15   e , the gap between the slider pivot and the slider among arms surface d 6 , the slider among arms surface  15   f , and the slider among arms surface radius r 3  as shown in  FIG. 10   d  also apply to the slider  15 ″ shown in the present illustration. 
       FIG. 31   b  is an isometric front top view schematic illustrations of a channeled disc  13 ″, an angular adjustment bolt  14   a , a linear adjustment bolt  14   b , a slider  15 ″, and a rib  21  of the surgical retractor  2 ″, according to the second embodiment of the present invention. 
     The present illustration shows that channel  13   k  can have a lateral section shape that is closed in all directions. 
       FIG. 32   a  is a top view schematic illustration of a channeled disc  13 ″ of the surgical retractor  2 ″, according to the second embodiment of the present invention, upon which a section plane g-g is marked. 
       FIG. 32   b  is a cross sectional view g-g illustrations of the channeled disc  13 ″ of the surgical retractor  2 ″, according to the second embodiment of the present invention. 
     The present illustration shows channeled disc wire holes  13   p , which can be threaded with electric wire to provide electric power to the lighting system. 
       FIG. 33  is a top view schematic illustration of a surgical retractor  2 ″, according to the second embodiment of the present invention, upon which a section plane h-h is marked. 
       FIG. 34  is a cross sectional view h-h illustration of the surgical retractor  2 ″, according to the second embodiment of the present invention. 
     The section plane shows two ribs  21 , the left one of which having a larger rib working arm length d 9 . The dimensions of its rib opening angle δ and slider pivot distance from the grooved disc central perforation center d 20  are also larger. 
     The dimensions of the rib opening angle δ and the slider pivot distance from the grooved disc central perforation center d 20  are respectively determined by the extent to which the angular adjustment bolt  14   a  and the linear adjustment bolt  14   b  are screwed in relative to slider  15 ″. 
     The combination of dimensions given here is one private case of many possible cases and combinations, as well as occasional replacement of ribs  21 . 
       FIG. 35   a  is a top view schematic illustration of a slider of the surgical retractor  2 ″, according to the second embodiment of the present invention, upon which a section plane i-i is marked. 
       FIG. 35   b  is a cross sectional view i-i illustrations of a slider  15 ″ of the surgical retractor  2 ″, according to the second embodiment of the present invention. 
     The slider  15 ″ of the surgical retractor  2 ″ of the second embodiment has three portions, a slider upper portion  15   p , a slider mid portion  15   q , and a slider lower portion  15   r.    
     In the upper portion  15   p , there is a perforation, all or part of which comprises slider first interior thread  15   m . In the mid portion  15   q , there is a perforation, all or part of which comprises slider second interior thread  15   n.    
     The three portions have an upper portion length d 21 , a mid portion length d 22 , and a lower portion length d 23 , respectively. The dimension of the upper portion length d 21  is smaller than that of lower portion length d 23 , and the dimension of the mid portion length d 22  is smaller than those of both. This serves the purpose of conforming the shapes and dimensions of the slider  15 ″ to those of other components with which it is engaged, for smooth and efficient use. 
       FIG. 36   a  is an isometric front top view schematic illustration of a surgical retractor  2 ″, equipped with an opening mechanism first type  60   a , according to the second embodiment of the present invention. 
       FIG. 36   b  is a side view schematic illustration of a surgical retractor  2 ″, equipped with an opening mechanism first type  60   a , according to the second embodiment of the present invention. 
     This variant includes an opening mechanism first type  60   a , which facilitates linear opening of the ribs  21 , and an external disc  19  to prevent undesired linear closing. 
     The present illustration shows the opening mechanism first type  60   a  slightly separated upwards from the other assemblies of the surgical retractor  2 ″. The present illustration also shows lamps  51   b.    
       FIG. 37  is an exploded, isometric front top view schematic illustration of a surgical retractor  2 ″, according to the second embodiment of the present invention. 
     The surgical retractor  2 ″ according to the second embodiment includes several assemblies, the mechanism for transferring of linear and rotational movements  10 ″, the ribs assembly  20 , the lighting assembly  50 ″, and the opening mechanism first type  60   a.    
     The mechanism for transferring of linear and rotational movements  10 ″ includes the sliders  15 ″, slider pivots  15   j , angular adjustment bolts  14   a , the channeled disc  13 ″, and a base disc  18 . 
     The channeled disc  13 ″ can be made of various materials, also including metals or materials transparent to x-rays, such as plastic material, and can be designated for single-time use. 
     The base disc  18  is attached to the bottom of the channeled disc  13 ″ and serves as a cover for electrical wires, (not shown in the present illustration), which provide electrical supply to lighting assembly  50 ″, which can also be composed of various materials, also including metals or materials transparent to x-rays. 
     Each rib  21  engages with a slider  15 ″ by means of a replaceable slider pivot  15   j , which can be made of various materials, also including metals or materials transparent to x-rays. 
     Slider  15 ″ includes a slider first interior thread  15   m , into which is screwed an angular adjustment bolt  14   a , and by means of which the angular opening of rib  21  can be determined. The linear opening of ribs  21  can be done by means of activating pushing forces, directly by an operator&#39;s hand, in an opening direction, upon the sliders  15 ″. After obtaining sufficient opening, the external disc  19  is rotated into a state that prevents unwanted closing back. 
     An additional option for performing opening is by means the opening mechanism first type  60   a . Downward force, (in the orientation of the present illustration), on the opening mechanism ring  64  causes opening mechanism arms  63  to activate linear opening force upon the opening mechanism sliders  64 , and when these are engaged with the sliders  15 ″, the sliders  15 ″ are subject to linear opening forces. After performance of the linear opening, the external disc  19  is rotated to a state that prevents closing back and the opening mechanism first type  60   a  is removed from the area in which the medical procedure is performed. 
     Following is a list of possible materials that can be used for various components of the surgical retractor  2 ″ according to the embodiments of the present invention. This list is in no way limiting the present invention to the use of any specific materials. 
     The channeled disc  13  and the external disc  19  can be made of nylon 6/10 or polycarbonate. 
     The ribs  21  can be made of nylon 6/10+20%-30% carbon fiber or stainless steel such as stainless steel 316L. 
     The slider  15  can be made from stainless steel such as stainless steel 316L or from brass. 
     The opening mechanism first type  60   a  can be made from stainless steel such as stainless steel 316L. 
       FIG. 38  is a top view schematic illustration of a surgical retractor  2 ″ equipped with an opening mechanism first type  60   a , according to the second embodiment of the present invention, upon which a section plane j-j is marked. 
       FIG. 39  is a cross sectional view j-j illustration of the surgical retractor  2 ″, equipped with an opening mechanism first type  60   a , according to the second embodiment of the present invention. 
     Outward linear movement, in the present illustration leftwards, of the slider  15 ″, which is shown on the left in the present illustration, will result in linear opening motion of the left rib  21 , as a result of force applied by the slider pivot  15   j , which is connected to the slider  15 ″. 
     Rotation of the linear adjustment bolt head  14   c  assembled to the angular adjustment bolt  14   a  in a direction that will screw it inward, will result in applying torque to the upper part of rib  21 , resulting in rotational opening. 
     The present illustration shows that the opening mechanism first type  60   a  includes an opening mechanism pole  61   a , upon which is mounted an opening mechanism arms ring  62 , which can move along its length. 
     The opening mechanism arms ring  62  is connected to opening mechanism arms  63  by means of opening mechanism arm upper pivots  63   a . The other end of each opening mechanism arm upper pivot  63   a  is connected by means of an opening mechanism arm lower pivot  63   b  to an opening mechanism slider  64  which conforms to the opening mechanism base  65 , so as to enable its linear radial movement. 
     When an axial force F 5  is applied to the opening mechanism arms ring  62 , downward movement, in the view shown in the present illustration, of the opening mechanism arms ring  62  is achieved, which is transmitted into radial force F 6  activated upon opening mechanism slider  64 . This force can serve to move the slider  15 ″ in linear outward movement. 
       FIG. 40  is a side view schematic illustration of an angular adjustment bolt  14   a , a slider  15 ″, a slider pivot  15   j , and a rib  21 , according to the second embodiment of the present invention. 
     Screwing the angular adjustment bolt  14   a  into the slider first interior thread  15   m  (not shown in the present drawing), of the slider  15 ″ causes the activation of moment upon the rib  21 , resulting in rotational movement of rib  21  around the slider pivot  15   j  relative to the slider  15 ″. 
     The shapes and dimensions of the slider pivot hole  15   e , the gap between the slider pivot and the slider among arms surface d 6 , the slider among arms surface  15   f , and the slider among arms surface radius r 3 , as described in  FIG. 10   d  also apply to the slider  15 ″ shown in the present illustration. 
       FIG. 41  is an isometric front top view schematic illustration of a slider  15 ″, and an opening mechanism slider  64  of a surgical retractor  2 ″, according to the second embodiment of the present invention. 
     The opening mechanism slider  64 , during the execution of linear opening, activates radial force F 6 , upon the slider  15 ″, in the direction of the arrow shown in the present illustration. 
       FIG. 42  is an isometric front top view schematic illustration of a slider  15 ″, and a segment of the external disc  19  of a surgical retractor  2 ″, according to the second embodiment of the present invention. 
     External disc  19  includes, for every slider  15 ″, an external disc stair  19   h  which after linear opening and after the rotation of the external disc  19  to the desired state prevents the slider  15 ″ from moving back in the direction of linear closing. 
     The external disc  19 , shown in the present illustration, includes for each slider  15 ″, one external disc stair  19   h  designated for it, however there is no prevention, according to the present invention, from including more than one external disc stair  19   h  for each slider  15 ″ in the external disc  19 , so as to be suitable for various degrees of linear opening. 
     Upon completion of the surgical procedure, the external disc  19  can be rotated back so that the external disc stairs  19   h  do not prevent linear movement in a closing direction of the sliders  15 ″. In this state, as a result of the pressure of the body tissue in the area of the procedure, and the pressure of the flexible sleeve  23 , if it is assembled, the ribs  21 , (not shown in the present illustration), close, namely they draw closer to each other, thus facilitating their removal from the patient&#39;s body. 
       FIG. 43  is an exploded, isometric front top view schematic illustration of an opening mechanism first type  60   a  of a surgical retractor  2 ″, according to the second embodiment of the present invention. 
     The opening mechanism arms ring  62  has an opening mechanism arms ring central hole  62   a , which grants it the ability to move along the length of the opening mechanism pole  61   a , when the opening mechanism pole  61   a  is engaged within the opening mechanism arms ring central hole  62   a . Furthermore, the opening mechanism arms ring  62  is equipped with pairs of opening mechanism arms ring arms  62   b , each pair being connected, by means of an opening mechanism arm upper pivot  62   a , to an opening mechanism arm  63 , near one of its ends. Near its other end, the opening mechanism arm  63  is connected, by means of an opening mechanism arm lower pivot  63   b , to an opening mechanism slider  64 . 
     The opening mechanism arm  63  has ability for rotational movement relative to opening mechanism arm upper pivot  63   a  and to an opening mechanism arm lower pivot  63   b.    
     The opening mechanism base  65  has an opening mechanism base hole  65   a , which serves for its connection to the opening mechanism pole  61   a.    
     The opening mechanism base  65  includes opening mechanism base grooves  65   b , each of which serves to enable and guide movement within and along opening mechanism slider  64 . 
     Both sides of opening mechanism base groove  65   b  have two opening mechanism base tracks  65   c.    
     The opening mechanism slider  64  has an external shape and dimensions that are suitable to receive force by means of an opening mechanism arm lower pivot  63   b  from an opening mechanism arm  63 , in order to perform linear movement within an opening mechanism base groove  65   b  upon a pair of opening mechanism base tracks  65   c , and in order to transmit force to a slider  15 ″ (not shown in the present illustration). 
     This external shape also includes an opening mechanism slider upper channel  64   a , an opening mechanism slider bottom channel  64   b , two opening mechanism slider side channels  64   c , and an opening mechanism slider pushing portion  64   d.    
     All of the features of the ribs  21 , the flexible sleeve  23  and the central rod  30  as shown in  FIGS. 2   a - 2   c ,  3   b ,  7   a ,  10   a ,  10   e - 10   h ,  11 ,  12   a - 12   c ,  13   a - 13   c ,  14   a - 14   h ,  18   a - 18   f ,  20 - 25 ,  27   a - 27   f , and  28 , and their accompanying descriptions, also apply to their use in the surgical retractors  2 ″ in accordance with all the embodiments of the present invention. 
       FIG. 44   a  is an exploded, isometric top view schematic illustration of an opening mechanism second type  60   b  of a surgical retractor  2 ″, according to the second embodiment of the present invention. 
     The opening mechanism second type  60   b  operates in a similar manner to that of the opening mechanism first type  60   a , (not shown in the present illustration), however it is constructed so as to enable the surgeon to view through its center when opening. For this purpose, an opening mechanism cylinder  61   b  replaces the opening mechanism pole  61   a , (not shown in the present illustration). 
     The opening mechanism cylinder  61   b  has an opening mechanism cylinder internal diameter  61 D of a predetermined minimum value which ensures a sufficiently large visual range. On the external side of the opening mechanism cylinder  61   b  there is an opening mechanism cylinder external thread  61   ba . The opening force is transmitted manually or by means of an engine, (not shown in the present invention), to opening mechanism nut  66 , which in turn presses on the opening mechanism arms ring  62 . 
     The opening mechanism arms ring central hole  62   a  is large enough, and conforms to the external dimensions of the opening mechanism cylinder  61   b.    
     The opening mechanism nut  66  includes an opening mechanism nut body  66   a  containing an opening mechanism nut internal thread  66   b , which conforms to opening mechanism cylinder external thread  61   ba.    
       FIG. 44   b  is an isometric front top view schematic illustration of an opening mechanism second type  60   b  of the surgical retractor  2 ″, according to the second embodiment of the present invention. 
     Both the opening mechanism first type and opening mechanism second type can also be composed of various materials, also including metals, plastics, and materials transparent to x-rays. 
       FIG. 45   a  is a front view schematic illustration of a surgical retractor  2 ′″ according to a third embodiment of the present invention. 
     The third embodiment includes, as will be further shown, mechanisms for generation of radial, linear, and angular movement of the ribs  21 , similar to the mechanisms of the surgical retractor  2 ′ according to the first embodiment of the present invention, however the transmission  17 ′″ of the third embodiment is much simpler. Likewise, an auxiliary handle  59   a  is added to facilitate the insertion of the ribs  21  into the body of the operated patient. 
     The auxiliary handle  59   a  can be composed of metal and is removed from the surgical retractor  2 ′″ after insertion is completed. 
       FIG. 45   b  is an isometric top view schematic illustration of a surgical retractor  2 ′″ according to a third embodiment of the present invention. 
     The present illustration shows a wrench  59   b  (such as ratchet wrench) mounted on the surgical retractor  2 ′″. The wrench  59   b  serves for transmission of manual force to initiate rotational movement, causing the linear radial movement. 
     The wrench  59   b  can be composed of metal, and can be removed and taken away, and even returned during performance of the medical procedure. 
       FIG. 46 , is an exploded, isometric side bottom view schematic illustration of a surgical retractor  2 ′″, up to elements, according to the third embodiment of the present invention. 
     The lighting assembly  50 ′″, according to the third embodiment of the present invention, also includes lamps  51   b , five in the configuration shown in the present illustration. The lamps  51   b  can also be of liquid emitting device (LED) type, and are fed electric power from electric wires  51   g . Under each lamp  51   b , there can be a a lamp window  51   f.    
     Likewise, the surgical retractor  2 ′″ according to the third embodiment includes a camera  53 , which is connected to camera cable  53   a . Camera  53  can also be a video camera, which provides the surgeon with real time visual display. The lighting for camera  53  is provided by lamps  51   b.    
     The mechanism for transferring of linear and rotational movement  10 ′″, according to the third embodiment of the present invention also includes 
     The mechanism for transferring of linear and rotational movement  10 ′″, according to the third embodiment of the present invention also includes cover disc  11 ′″, grooved disc  12 , channeled disc  13 ′″, six angular adjustment bolts  14   a , six sliders  15 ′″ and a transmission  17 ′″. The ribs assembly  20 , according to the third embodiment of the present invention, includes six ribs  21 . 
     According to another variant of the third embodiment of the present invention the quantity of ribs  21  is other than six, and therefore the quantities of the other elements, quantified as six in the present illustration, are correspondingly quantified. 
     The central rod  30 ′″, according to a variant of the present invention, includes a central rod tail  30   a ′″, and central rod head dome  30   c.    
     As noted, the quantities of elements noted above are in no way limiting the present invention, and there may be other variant of quantities, such as eight ribs  21 . The positions and connections of these assemblies, also with regard to each other, their functions, and methods of operation, will be specified in the following. 
     The majority of components of the surgical retractor  2 ′″ according to the third embodiment of the present invention are transparent to X-ray radiation and are designated for single use. 
       FIG. 47   a , is an isometric front top view schematic illustrations of a grooved disc  12 , a slider  15 ′″, an angular adjustment bolt  14   a  and a transmission  17 ′″, according to the third embodiment of the present invention. 
     The present illustration demonstrates the method of engagement of the grooved disc  12 , the slider  15 ′″, the angular adjustment bolt  14   a , and a transmission  17 ′″, according to the third embodiment of the present invention. 
       FIG. 47   b  is an isometric front bottom view schematic illustrations of a grooved disc  12 , a slider  15 ′″, an angular adjustment bolt  14   a , and a transmission  17 ′″, according to the third embodiment of the present invention. 
     The present illustration demonstrates the method of engagement of the grooved disc  12 , the slider  15 ′″, the angular adjustment bolt  14   a  and a transmission  17 ′″, according to the third embodiment of the present invention. 
     The illustration shows that the grooved disc teeth  12   e  are engaged with transmission first cog wheel  17   f ′″ and that angular adjustment bolt  14   a  has an angular adjustment bolt head  14   aa.    
       FIG. 48  is an isometric front top view schematic illustration of a transmission  17 ′″, according to the third embodiment of the present invention. 
     The transmission  17 ′″ according to the third embodiment of the present invention is extremely simple, made of one cylindrical part, including a transmission shaft  17   b ′″, a transmission first cog wheel  17   f ′″, a transmission ring  17   j , and a transmission bolt head  17   i.    
       FIG. 49   a  is an isometric front top view schematic illustration of a channeled disc  13 ′″, according to the third embodiment of the present invention. 
     The channeled disc  13 ′″ according to the third embodiment has a structure similar to that of the channeled disc  13 ′ according to the first embodiment, and both have common features. Channeled disc wall  13   b ′″ has channeled disc wall holes  13   d  and the present illustration shows channels  13   k . Furthermore, it has channeled disc transmission niche  13   s . The spatial shape of the channeled disc transmission niche  13   s  conforms to the transmission first cog wheel  17   f , enables rotational movement of, and provides a resting point for transmission first cog wheel  17   f  (not shown in the present drawing). 
     The channeled disc upper surface  13   t  is etched with channel upper opening  13   l . The channeled disc perforation  13   e , the channeled disc lamp housing  13   q , of which there are five in the present illustration, and a channeled disc camera housing  13   r  pierce all the way through the channeled disc  13 ′″. 
     The channeled disc  13 ′″ can be made as one piece. 
       FIG. 49   b  is an isometric front top view schematic illustration of a channeled disc  13 ′″ and a transmission  17 ′″, according to the third embodiment of the present invention. 
     The transmission  17 ′″ is in its proper place relative to channeled disc  13 ′″, and the transmission first cog wheel  17   f  is within the channeled disc transmission niche  13   s.    
       FIG. 49   c  is an isometric front bottom view schematic illustration of a channeled disc  13 ′″, according to the third embodiment of the present invention. 
     Alongside the channeled disc base  13   a , the illustration shows channeled disc long slots  13   f.    
       FIG. 50  is an isometric front top view schematic illustration of a guarding cover  58 ′″, according to the third embodiment of the present invention. 
     The guarding cover  58 ′″ have a guarding cover disk  58   a  and guarding cover wall segments  58   d , of which there are two in the present illustration. 
     In the center of the guarding cover disk  58   a  there is a guarding cover perforation  58   b  through which the operating surgeon can see, and through which the operating tools are inserted. Likewise, guarding cover disk  58   a  has a guarding cover niche  58   c , which conforms to the diameter size of the transmission bolt head  17   i.    
     Each guarding cover wall segment  58   d  has a guarding cover wall hole  58   e , through which a casing bolt  70   a  (not shown in the present drawing) passes. Casing bolt  70   a  serves to connect the guarding cover  58  to the casing  70 ′″ (not shown in the present drawing). 
       FIG. 51   a  an isometric front top view schematic illustration of a slider  15 ′″ and an angular adjustment bolt  14   a , according to the third embodiment of the present invention. 
     Rotation of the angular adjustment bolt head  14   aa  causes linear movement of the angular adjustment bolt  14   a  relative to the slider  15 ′″, resulting in a rotational movement around the slider pivot  15   j  relative to the slider  15 ″ of a rib  21  (not shown in the present drawing), such as was described with regard to  FIG. 31   a.    
       FIG. 51   b  is an exploded, isometric front top view schematic illustration of a slider  15 ′″, according to the third embodiment of the present invention. 
     The slider  15 ′″ includes a slider main body  15   a , the top part of which has a slider upper body  15   b , and one end of which has two slider arms  15   d . Likewise, it has a slider pin hole  15   c  from which a slider pin  15   i  protrudes, and two slider pivot holes  15   e  into which a slider pivot  15   j  is assembled. 
     This resembles the structure of the slider  15 ′, according to the first embodiment of the present invention, as shown in  FIG. 10   b , and according to the description provided for  FIG. 10   b.    
     The slider  15 ′″ can also include a slider friction reducer  15   h , (not shown in the present drawing). Furthermore, the slider  15 ′″, on its more distant end from the slider arms  15   d , has a slider third interior thread  15   w , which is designated to receive, by screwing, a slider bolt  15   t , for the purpose of connection to a slider back portion  15   s.    
     The slider back portion  15   s  is connected to a slider upper portion  15   p , both of which have a slider first interior thread  15   m , which is designated to receive, by screwing, the angular adjustment bolt  14   a  (not shown in the present drawing). 
     The slider back portion  15   s  has a slider bolt hole  15   u  through which a slider bolt  15   t  moves for the purpose of connection to the slider main body  15   a.    
     According to a variant of the third embodiment of the present invention, the slider back portion  15   s  and the main slider upper portion  15   p  are composed as one piece. 
     According to another variant of the third embodiment of the present invention, the slider back portion  15   s , the main slider upper portion  15   p , and the slider main body  15   a  are composed as a one piece. 
     The slider pin  15   i  is designated to be engaged within a curved groove  12   b  of a grooved disc  12  (not shown in the present drawing), for the purpose of taking part in generating a radial linear movement of a rib  21 , as described in  FIGS. 19   a  and  19   b  and in their accompanying descriptions. 
       FIG. 52  is a side view schematic illustration of a casing  70 ′″, according to the third embodiment of the present invention. 
     The casing  70 ′″ is composed of a cover disc  11 ′″ and a channeled disc  13 ′″. 
       FIG. 53   a  is a top view schematic illustration of the surgical retractor  2 ′″, according to the third embodiment of the present invention, upon which a section plane k-k is marked. 
       FIG. 53   b  is a cross sectional view k-k illustration of the surgical retractor  2 ′″, according to the third embodiment of the present invention. 
     The state shown in the present illustration is prior to insertion of the surgical retractor  2 ′″ into the body of the patient about to be operated on. 
     Every angular adjustment bolt  14   a  touches a rib  21 , and every slider pin  15   i  is engaged within the grooved disc  12 . 
     The auxiliary handle  59   a  is connected to the central rod tail  31 , which is connected to the central rod head dome  32 . 
     The auxiliary handle  59   a  and the central rod head dome  32  are in contact with the ribs  21  in the manner shown in the present illustration, so that relative linear movement between the auxiliary handle  59   a  and the surgical retractor  2 ′ is prevented. 
     During performing insertion of the surgical retractor  2 ′″ into the patient&#39;s body, the surgeon can hold the auxiliary handle  59   a  by hand, activate inserting force, and direct it. After completing insertion, the auxiliary handle  59   a  is disconnected from the central rod tail  31  and taken away, and afterward, radial opening of the ribs  21  is performed, and the central rod tail  31  and central rod head dome  32  are removed and taken away. 
     The central rod tail  31  and the central rod head dome  32  according to another variant are composed as one piece. 
     The auxiliary handle  59   a , the central rod tail  31  and the central rod head dome  32  can be composed of metal. 
       FIG. 53   c  is a cross sectional view k-k illustration of three elements of the surgical retractor  2 ′″, according to the third embodiment of the present invention. 
     To enable connection and disconnection of the auxiliary handle  59   a  and the central rod head dome  32  to and from the central rod tail  31 , both ends of the central rod tail  31  are equipped with central rod screws  31   a , the auxiliary handle  59   a  has an auxiliary handle interior thread  59   aa , and the head dome  32  has a central rod head dome interior thread  32   a.    
       FIG. 54  is a side view schematic illustration of the surgical retractor  2 ′″, equipped with an opening mechanism third type  60   c , according to the third embodiment of the present invention. 
     The opening mechanism third type  60   c  facilitates a uniform rotational movement opening of the ribs  21 . Rather than having each angular adjustment bolt  14   a  rotate separately and generate a rotational movement opening of one specific rib  21 , the opening mechanism third type  60   c  enables uniform rotation of the angular adjustment bolts  14   a.    
       FIG. 55   a  is a side view schematic illustration of an angular adjustment bolt  14   a , according to some variant of the third embodiment of the present invention, upon which a section plane l-l is marked. 
     The angular adjustment bolt  14   a , shown in the present illustration, is missing a linear adjustment bolt head  14   c  however has a linear adjustment bolt tail  14   d.    
       FIG. 55   b  is a cross sectional view l-l illustration of the angular adjustment bolt  14   a , according to some variant of the third embodiment of the present invention. 
     The linear adjustment bolt tail  14   d  may have a circular cross section shape  14   e , shown here magnified relative to the previous illustration. 
       FIG. 56  is an isometric side top view schematic illustration of a opening mechanism third type cog wheel  60   ca , according to some variant of the third embodiment of the present invention. 
     The opening mechanism third type cog wheel  60   ca  has an opening mechanism third type cog wheel central hole  60   cb , which has dimensions and shape such as those of the non-circular cross section shape  14   e.    
     Every opening mechanism third type cog wheel  60   ca  is a component of a bevel gear that serves for uniform rotation of all of the angular adjustment bolts  14   a  of a surgical retractor  2 ′″ (not shown in the present drawing). 
     The non-circular cross section shape  14   e  and the identical dimensions of the sections of the linear adjustment bolt tail  14   d  (not shown in the present drawing) and the opening mechanism third type cog wheel central hole  60   cb  are designated to enable transmission of rotational movement from an opening mechanism third type cog wheel  60   ca  to a linear adjustment bolt tail  14   d , while concurrently enabling linear movement between the two, which is required when the angular adjustment bolt  14   a  rotates within the main slider upper portion  15   p  (not shown in the present drawing), thus shifting its location. 
       FIG. 57   a  is an exploded isometric front bottom view schematic illustration of an opening mechanism third type  60   c , and angular adjustment bolts  14   a , according to some variant of the third embodiment of the present invention. 
     All the opening mechanism third type cog wheels  60   ca  can be engaged with an opening mechanism third type bevel gear ring  60   cc.    
     All the linear adjustment bolt tails  14   d  can be each disposed within one separate opening mechanism third type housing wall hole  60   cf  of an opening mechanism third type housing wall  60   ce , of an opening mechanism third type housing  60   cd.    
       FIG. 57   b  is an exploded isometric front top view schematic illustration of an opening mechanism third type  60   c , and angular adjustment bolts  14   a , according to some variant of the third embodiment of the present invention. 
     Rotation, whether manual or motor-powered, of the opening mechanism third type bevel gear ring  60   cc , generates the uniform rotational movement opening of the ribs  21 . 
     The structure of the surgical retractor  2 ′″, according to the third embodiment of the present invention, enables its manufacture at sufficiently low costs in order to be viably used for single use, and including almost no components capable of blocking x-ray radiation. In particular, the cover disc  11 ′″, the channeled disc  13 ′″, the angular adjustment bolts  14   a , the angular adjustment bolt heads  14   aa , the slider  15 ′″, the ribs  21 , and the guarding cover  58 ′″ are all composed of material or materials transparent to x-ray radiation. 
     These structural materials, in addition to being transparent to x-ray radiation, must also have mechanical qualities suitable for their purpose, such as mechanical strength, elasticity, and environmental durability. Likewise, they must be suitable for medical use in surgical procedures on human tissue. 
     A good example of a suitable material is ULTEM HU1000 Resin, which is a Polyetherimide, a material defined as biocompatible, namely a material that is nontoxic and does not pose any risk of damage to biological systems. 
       FIG. 58   a  is a side view schematic illustration of a surgical retractor  2 ′″, according to the third embodiment of the present invention, after insertion and opening for the purpose of performing far lateral micro discectomy and discoplasty (FLMDD). 
     Use of surgical retractor  2 ′″, according to the third embodiment of the present invention for the purpose of this operation also provides the following advantages:
         minimal distraction and disruption of soft tissues (such as muscles, ligaments, nerves),   saving height of intravertebral space,   increasing sizes of intravertebral foramina,   lowering of radicular pains,   decreasing facet intra articular pressure,   preventing facet osteoarthritis and development of future spinal stenosis,   sparing unnecessary future vertebral fusion,   maximal saving vertebral function, concerning motional freedom,   less foreign bodies in to the patient&#39;s body,   less infectious complications,   less postoperative scar,   less postoperative pain syndrome, and   less delayed intravertebral discuses herniations on the different levels.       

       FIG. 58   b  is a side view schematic illustration of a surgical retractor  2 ′″, according to the third embodiment of the present invention, after insertion and opening for the purpose of performing a translaminar micro discectomy. 
     Use of surgical retractor  2 ′″, according to the third embodiment of the present invention for the purpose of this operation also provides the following advantages:
         minimal damage of ligaments and muscles, involving vertebral fixation,   prevention of postoperative additional operations for vertebral fixations,   prevention of delayed postoperative additional herniations of discuses (due to vertebral instability) on the other levels of vertebrae.       

       FIG. 59  is a flow chart that schematically illustrates a method of operation for minimal invasive (MI), using a surgical retractor  2 ′″, according to the third The method shown here details the steps for performance of several types of operations using the surgical retractor  2 ′″, according to the third embodiment however this is in no way limiting the method of the present invention to these two types of surgery. 
     The method includes the stages of: 
     making an incision of skin until superficial fascia; (stage  301 ); the incision is made at a length suitable for the type of surgery, such as in the case of far lateral micro discectomy and discoplasty, the incision is typically 1.5 to 3.0 centimeters, while for translaminar micro discectomy, an incision typically of 0.5 to 1.0, 
     holding an auxiliary handle  59   a  of a surgical retractor  2 ; ( 302 ) 
     inserting ribs  21  and a central rod  30  of said surgical retractor  2  into a patient body; ( 303 ) 
     for the translaminar micro discectomy operation the insertion is until paravertebral and intravertebral space, and for the translaminar micro discectomy operation the insertion is 
     removing said auxiliary handle  59   a  from said surgical retractor  2 ; ( 304 ) 
     rotating a wrench  59  for granting rotational movement to a grooved disc  12  causing radial linear opening movement of the ribs  21 ; ( 305 ) 
     removing said central rod  30  from the surgical retractor  2 ′″; ( 306 ) 
     removing said wrench  59  from the surgical retractor  2 ′″; ( 307 ) 
     performing a medical procedure selected from a group consisting of replacing intravertebral discus, removal of intravertebral discuses, fusion of vertebra, operations of anterior cervical discectomy and fusion, operations of trans laminar burr hole and discectomy, far lateral discectomy and discoplasty, multi level spinal stenosis, multi level uni lateral and bilateral laminotomy, and trans oral vertebral fusion; ( 308 ) for a translaminar micro discectomy operation: 
     making a burr hole lateral of lamina; ( 309   a ) 
     inserting additional instruments via said burr hole; ( 309   b ) 
     performing discectomy; ( 309   c ) 
     closing the surgical retractor&#39;s ribs ( 21 ); ( 310 ) 
     taking out the surgical retractor  2 ′″ from the patient&#39;s body ( 311 ) 
     suturing the patient&#39;s skin. ( 312 ) 
     Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.