Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/32—Surgical cutting instruments
  • A61B17/3201—Scissors
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/04—Surgical instruments, devices or methods, e.g. tourniquets for suturing wounds; Holders or packages for needles or suture materials
  • A61B17/06—Needles ; Sutures; Needle-suture combinations; Holders or packages for needles or suture materials
  • A61B17/062—Needle manipulators
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/30—Surgical pincettes without pivotal connections
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
  • B25B9/00—Hand-held gripping tools other than those covered by group B25B7/00
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
  • B25B9/00—Hand-held gripping tools other than those covered by group B25B7/00
  • B25B9/02—Hand-held gripping tools other than those covered by group B25B7/00 without sliding or pivotal connections, e.g. tweezers, onepiece tongs
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B2017/00526—Methods of manufacturing

Definitions

• This invention relates to a hand-held surgical tool used in microsurgery and, more particularly, to a icroinstrument such as a forceps, scissors, needle holder, or the like which can be used with rotational microsurgery techniques.
• microsurgical techniques are extremely demanding and pose difficulties unique to their field.
• the size of needles, thread and body parts are microscopically small, and typically, microsurgery is performed under 20x magnification.
• inefficiencies in the manual movement a surgeon is required to perform during an operation become an area of major concern since microsurgery requires very precise, critical movements, and the operations are quite lengthy, typically requiring hundreds if not thousands of distinct hand, wrist and arm movements.
• the tools used in microsurgery are generally scissor-like instruments which have a pair of pivoted levers joined - - at a common pivot with a handle at one end and a pair of jaws at the other end, and which are opened and closed by moving the handle.
• Another similar type of hand-held instrument used in microsurgery is of the tweezer or forceps type in which the two deflectable spaced tongs are joined at one end and are brought together at the other end by finger pressure.
• the present invention is directed to instruments of very high precision, much higher than that required for standard surgical instruments.
• microsurgery is performed under 20x magnification, and accordingly, any misalignment in the microsurgical tool is amplified accordingly.
• amplification of certain types of misalignment results from the typical pivotal mating of tool halves.
• the quality of tools used in microsurgery is also subject to rigorous demands by virtue of the small sizes and delicate composition of the surgical arteries and body parts manipulated by those tools. Blood vessels cut, dilated, grasped and sutured by the instruments are typically in the range of 0.5 mm in diameter. Thread employed in suturing is finer than human hair and is gossamer fine.
• the curved needles are as fine as a baby's eyelash having a diameter of about 70 microns, i.e., .070 millimeter. If the microsurgical needle is grasped and is bent by the forceps, then it is no longer useful. Further, the forceps is used to grasp the fine thread to assist in tying knots for a stitch. In other instances, a surgeon will grasp a curved microsurgical needle with a conventional needle holder in his dominant hand and with a forceps in the non-dominant hand he will grip and rotate the needle tip through a 90° arc.
• the slightest opening of the tip of a forceps or scissors, for example, would render the tool very difficult, if not impractical for use in a delicate operation, especially operations of extended duration involving many hundreds if not thousands of tool manipulations.
• a microinstrument which guarantees constant alignment during the full range of opening and closing of the forceps-type device and that, regardless of the position of the instrument and the direction of manipulatory forces being applied to the instrument, the ends will always come together in perfect alignment, and will not move or twist relative to one another.
• a microinstrument having the above improvements which can be rotated easily with finger movement rather than with wrist movement.
• the rotational surgical technique presents a somewhat unique problem in providing a proper alignment between tips comprising mating halves that are drawn together by a surgeon's finger pressure. A crossing over of the tips in a direction perpendicular to that of tool closure is much more likely when the rotation surgical technique is employed, since the surgeon is frequently rotating the tool while the two halves are pressed together.
• the present invention is directed to scissors which can be used in microsurgery, particularly the rotational type of microsurgical technique.
• a scissors instrument must be capable of rotation by the microsurgeon to almost any angle in that the surgeon must be able to compress the scissor tips together to form a cut in tissue or thread while at an awkward angle. Because the tips are so finely pointed in a forceps-like scissors, it is difficult to hold the scissor blades close together so that they properly shear through the tissue at such angles. Particularly, when the scissor blades are rotated away from a vertical plane (i.e., by the pronation or supination movements associated with these instruments) before compression toward one another.
• the duration of microsurgery operations is typically quite lengthy, e.g. 20 hours.
• the force to open or close the instrument if properly set, may reduce the amount of hand fatigue.
• a predetermined biasing force may be provided to bias the tool to open as the surgeon releases his grip on the tips.
• the alignment is continuous throughout the entire opening and closing range of the instrument, and should be as smooth and frictionless as possible. This is in contrast to many of the instruments currently provided to microsurgery practitioners.
• Typical alignment arrangements used in these instruments include a pilot pin on one part of the forceps which is in alignment with an opening on the opposite side of the forceps. Only when the forceps is in the final stages of closure, will the pin enter the associated opening to maintain alignment of the two sides of the forceps. When the instrument tips are fully open, the alignment pin is out of its associated, spaced opening. If the closing pressures of the surgeon's fingers are not exactly opposite and aligned normal to the longitudinal axis of the instrument, the tips will be out of alignment and the pin can miss the opening, thereby preventing the instrument from closing. Microsurgical instruments are expensive because of their high precision surfaces and fine tolerances.
• any unintentional impact to the tip of the tool is attended by a high probability that the tool will become damaged, perhaps rendering it incapable of further use. Therefore, it is desirable that such tools be capable of interchanging with replacement tips, especially with different tips capable of forming different operations.
• the precision of the mating portions comprising a microsurgical tool must be quite high. That is, the configurations of the mating portions must be reproduceable from exchangeable part to exchangeable part.
• many microsurgical tools are hand made by skilled craftsmen. As has long been apparent in other fields, such handmade tools do not lend themselves to such interchangeability, especially an inter- changeability that assures that the new tips have the necessary alignment for gripping microscopically fine microsurgical threads or needles, or for cutting.
• Another object of this invention is to provide a hand-held surgical instrument having a cylindrical grasping portion which permits the tool to be easily rotated during use and which has an alignment means which does not interfere with such rotation.
• Another object is to provide a hand-held surgical tool having removable and replaceable tips.
• Yet another object of the present invention is to provide a hand-held microsurgical tool having multiple points of alignment along its mating parts, a first point progressing toward the tip of the instrument as the two parts are mated, and the second point providing an early mating alignment adjacent the instrument tip.
• Yet another object of the present invention is to provide a scissors suitable for manipulation by rotational microsurgical techniques, which is suitable for cutting tissue and for the associated tasks of spreading tissue and dilating vessels.
• This invention relates to a microinstrument or hand-held surgical instrument, such as a forceps, scissors, needle holder, or the like which is adapted for use in microsurgery and has an alignment means which provides a smooth and near-frictionless constant alignment during the full range of opening and closing of the forceps.
• the alignment means comprises a cylindrical bar and a slot arrangement which is provided on the two sections of the instrument.
• the cylindrical bar and slot extend the major length of the instrument along the held shank portion. A portion of the cylindrical bar is always in the slot to insure alignment even when the functional end of the instrument is at the fully open position. As the instrument is closed, increasingly greater portions of the bar become seated in the slot, thus insuring even further alignment as the functional ends come together.
• the functional end of the tool can accommodate a variety of different tips to provide different surgical instruments. It is anticipated that the alignment arrangement and detachable tips will be used for forceps, needle holders, scissors and other surgical instruments which require alignment be maintained between the tips. By removing and replacing or changing the functional ends, the instrument can be converted to a forceps, needle holder or scissors as desired. Also, if the instrument is dropped and the tip is damaged, the tip can be readily replaced at a tremendous cost savings, since the inexpensive tip and not the much more expensive body of the instrument can be discarded and replaced.
• the surgical tool is provided with a cylindrical mid-portion which is grasped by the surgeon and may be rotated by mere finger movement. For example, if the tool is held between the thumb and forefinger, simply moving the thumb and forefinger produces rotation of the tool. This is important in suturing in microsurgery because the needles are so small and require numerous sutures that the surgeon can become fatigued in using a flat needle holder which requires wrist and arm movement to produce a single suture. Even if the forces applied to the cylindrical shank are skewed or applied in a fashion which would ordinarily case the tips to be misaligned, no such misalignment can occur because the alignment means always to maintains constant alignment during the full range of opening and closing.
• the present invention attains many of the aforestated objects by providing a hand-held microsurgical tool for use in microsurgery, which is comprised of an elongated body including a central cylindrical section having a longitudinal axis about which the body may be rotated by a surgeon.
• the central cylindrical section consists of first and second opposed, longitudinally extending portions joined at a closed end. Needle point ends on each of the first and second portions are located opposite from the closed end and movable toward and away from each other between closed and open positions respectively.
• Alignment means are provided for maintaining alignment of the needle point ends when in the open and closed positions and at all intermediate positions therebetween.
• the alignment means consist of an interior elongated guide member having an exterior smooth rounded surface, extending into said central cylindrical section and received in at least one of said first and second portions so as to be located within the configuration of the central cylindrical section and so as not to interfere with the rotation of the central cylindrical section of the tool.
• the present invention further obtains other objects as set forth above by providing a method of making a surgical instrument suitable for use with a rotatable surgical technique. The method forms a blank having a substantially cylindrical body and a substantially conical tip at one end of the blank. External threads are then formed at one end of the blank and the blank is cut substantially along its axis to form first and second opposed portions each having a tip at their one end.
• An internally threaded cap is provided dimensioned to receive said other end of the blank, and the first and second portions are threadably engaged with the cap to form a tool having tips at one end which can be displaced relative to each other.
• FIG. 1 is a perspective view of a surgical instrument embodying the novel features of the invention
• FIGS. 2 and 3 are side elevational views of the surgical instrument of FIGURE 1, shown in open and closed positions, respectively; -10-
• FIG. 4 is an elevational view of one mating half of the instrument of FIGS. 1-3.
• FIG. 5 is an inside plan view of one mating half of the instrument of FIGS. 1-3;
• FIG. 6 is an enlarged sectional view taken generally along lines 6-6 of FIG. 3;
• FIG. 7 is an enlarged cross-sectional view taken generally along the line 7-7 of FIG. 3;
• FIG. 8 is an enlarged, exploded, fragmentary view of the upper end of the tool of FIG. 2;
• FIG. 9 is an enlarged view of a scissor blade end of the scissors tool of FIGS. 1-8;
• FIG. 10 is an elevation view of the surgical tool having a forceps end;
• FIG. 11 is a view of the forceps of FIG. 10 in its closed position;
• FIGS. 12 is an elevational view of a surgical instrument according to the invention, having a tip adapted for use as a holder of microsurgical needles;
• FIG. 13 is an enlarged view of the tip portion of the instrument of FIG. 12;
• FIG. 13a is an even more enlarged view of the tip of the instrument of FIGS. 12 and 12;
• FIG. 14 is a surgical instrument according to the present invention, similar to the needle holder of FIGS. 12-13a, but having a conical tip which is not " bent or curved;
• FIG. 14a is an enlarged view of the tip of the instrument of FIG. 14;
• FIG. 15 is an enlarged view of the tip of the instrument of FIGS. 14, 14a shown in a completely closed position;
• FIG. 16 is an enlarged view of the tip of the instrument of FIGS. 14-15, shown in an open position.
• FIGS. 1-8 illustrate a scissors instrument 10 which, as will be seen, in addition to cutting, can be used to spread and grasp tissue, as well as dilating vessels.
• FIGS. 10 and 11 illustrate an embodiment of the present invention adapted to provide a a forceps instrument 110.
• FIGS. 12-16 illustrate a needle holder adapted for use with "micro-needles" that are as fine as a baby's eyelash, having a diameter of about 70 microns.
• microsurgical instruments 110 When adapted as forceps, microsurgical instruments 110 according to the present invention are used in conjunction with the aforedescribed "micro-needles" to anastomize and to tie knots with a fine nylon thread which is attached to the needle and which is finer than a human hair and is gossamer fine.
• FIGS. 1-8 a small forceps-like scissor instrument 10 is shown in FIGS. 1-8 having an operating end 11 including first and second tips or ends 12 and 14 which are movable between the open position (shown in FIG. 2) and the closed position (shown in FIG. 3) so as to grip a microsurgical needle or thread or to sever a thread or tissue.
• alignment means 38 hold scissor blade tips 12 and 14 in precise alignment to give a close shearing action as their respective flat interior faces 12a, 14a slide past one another.
• the illustrated scissor points are needle sharp having a diameter of only about 50 microns to 2mm when the tips are closed as seen in FIG. 3.
• the cutting edges 12c, 14c are inclined and are defined by the juncture of the inner edge of flat interior faces 12a, 14a and the adjacent edge of the conical surfaces.
• the half portions include flat interior surfaces 28 and 30 of the tool halves do not continue to the pointed end of the scissors tool (as they do for the forceps tool shown in FIGS. 10 and 11) . Instead the flat interior surfaces 28 and 30 stop at shoulders 28a and 30a at which begins the flat blade-forming surfaces 12a, 14a which define generally triangular shape shearing tips and which extend normal to the plane of the flat surfaces 28 and 30.
• the triangular shearing tip face 12a (which appears on edge) extends vertically.
• the outer semiconical shape surface of the tip 12 extends the length of the tip.
• Each of the scissors tips is identical in shape.
• This scissors surgeon's tool is particularly useful because it may be employed to do more tasks and to do more efficiently tasks accomplished with the large large conventional scissors which have a pivot pin and a wide handle portion requiring large hand movements to move the wide handle portions together to cause the scissors tips to do the cutting.
• Such wide handle scissors are impractical for doing a number of operations such as dilating vessels which can easily be done by inserting the fine pointed conical tips into the vessel. More specifically, the surgeon can, by pressing the tips together, form a very fine conical point, and can insert this fine point within the lumen of the vessel and then allow the points to spread apart to dilate the vessel.
• scissors is a much more compact instrument than the conventional large scissors currently used by microsurgeons, and also that the surgeon with fairly easy rotative movements of the scissors may cut tissue with a tool held in any of its 360° rotation positions unlike scissors which cut only when the handles are aligned vertically. Further, the scissors is particularly useful for dissecting and dilating vessels as well as cutting of tissue.
• slots 18, 20 are preferably semicircular in cross-section, so that the cylindrical key 38 is fully received in the joined half portions 18, 20, allowing the flat interior surfaces 28, 30 to engage upon complete closing of the instrument, as shown in FIG. 3.
• the key 38 extends substantially the entire length of each half portion 18, 20, having a first end 38a engaged by the halves 18, 20, at their closed end 22 and having an opposed free end 38b which stops just short of shoulders 28a, 30a.
• the key 38 is always received in at least a portion of slots 40, 42 even if the instrument is in its open position.
• the cylindrical key 28 has a substantial engagement with the slots 40, 42 at a point 46 adjacent the center of the instrument.
• the instrument is brought to the closed position of FIG. 3, increasingly greater lengths of key 38 are received by slots 40, 42, which is accomplished in a continuous smooth movement of minimum friction providing a heretofore unobtainable precision alignment between the mating halves.
• An important feature of the present invention is that the key and slot arrangement maintains alignment of the needle point ends 12, 14 when in the open and closed positions, and in all intermediate positions therebetween.
• An important feature provided by the present invention is that the degree of alignment increases as the tips are drawn together, with the alignment being provided over very nearly the entire length of the instrument, if desired. As illustrated, alignment is provided over at least 75% of the length of the displaceable halves of the instrument. Further, the alignment provided is smooth in operation since it is accomplished by a key or elongated guide member having an exterior smooth rounded surface being received within complementary shaped smooth rounded recesses of the slots 40, 42. In the preferred embodiment, not only are the key 38 and slots 40, 42, complementary-shaped, they are also machined to close tolerances for precise interengagement.
• the slots are precision milled to form matching semicylindrical key receiving slots.
• the key made from slightly oversized cylindrical stock, is machined to within 0.5 mils (0.0005 inches) of the slot diameter.
• the half portions, 18, 20, are matching halves cut from a common blank preferably cut by a precision electrical discharge cutting machine, to complement the precision of the key and slots, thereby ensuring exact alignment of the needle tips, even under the 20x magnification typically employed during microsurgery.
• the halves are complementary and mated because they are cut from the same blank in contrast to the usual surgical tool in which the halves are formed from their own single blank and machined before being combined for the first time in the instrument. While differences in shape or size between blanks may not appear to be significant to the human eye without magnification, the differences in size or shape between the halves when under 20 x magnification appear quite large and quite significant.
• the term "cylinder" as used to describe the preferred embodiment of the present invention is used in its broader sense and includes shapes that are developed ellipsoids or developed conical shapes. It is even contemplated that the key 38 could be diamond-shaped, i.e., a square cross section turned on one edge. This latter embodiment contemplates a generally V-shaped slot for receiving its respective half portion of the aligning key. Also, the present invention contemplates a square cross-section key not turned on edge, but presenting one of its flat faces to a key-receiving slot. As explained above, microinstruments of the type addressed by the present invention are frequently used in prolonged operations, and accordingly, any improved efficiency in manipulating the instrument is particularly advantageous.
• the two mating halves 18, 20 are conveniently provided with a spring bias force which tends to maintain those halves in their open position.
• the spring bias force is provided by the material and configuration of the mating halves, and their joined end 22.
• the two mating halves 18, 20, are compressed together at the closed end 22 and one or both of the halves is slightly bent apart so that the material of that half portion is "set", whereby, upon closing the instrument, a spring bias force tending to open the instrument is generated.
• the material from which the mating halves 18, 20, are formed must be suitable for this purpose, i.e., must generate a bias force when deflected from its "set” or bent position.
• Numerous materials, particularly metallic materials illustrating these qualities, are known in the art.
• the preferred materials are titanium or 420 stainless steel, although injected molded plastic or die cast metal could also be used. In particular, heat treating to obtain the desired hardness (as will be described below) , also imparts desirable spring bias characteristics to the titanium and stainless steel materials.
• cut-away window portions 48 are formed in each half portion 18, 20.
• the window portions 48 are also advantageous in reducing the overall mass of the instrument, a desirable feature in that fatigue experienced by a surgeon, especially during a lengthy operation, is significantly reduced.
• further weight reduction can be accomplished by "over-sizing" portions of one or either slot 41, 42 to thereby remove more metal.
• the oversizing will be done at the central location 46 of the slots 41, 42 so that here will always be guiding registration at the rear of the slots with the key 38 and with the tip portion of the slots and the key as the tips are brought together. It is to be understood that at least portions of the slots 40, 42 must be relatively close-fitting with the key 38 (as explained above) to provide the necessary alignment under 20x magnification.
• closed ends 51 of the half portions 18, 20 are provided with external threads 50 as best seen in Figure 8.
• the thread portions 50 do not make a true cylindrical path for the mating thread 52 on the cap 24.
• a locator shim 53 is provided and placed into locator shim recesses 54 in wall 30 of each half 18 and 20.
• the locator recesses have top and bottom walls 55 which abut end walls 56 on the locator shim 53 which herein is the form of a flat, metallic plate sized to fit snugly in the recesses.
• the thickness of the locator shim is such that when the halves 18 and 20 are placed together with the locator shim in the recess, the threads 50 cooperate to provide a true cylindrical thread; and thus, in effect, replace the metal lost during the electrical discharge machining of the blank.
• the locator shim 53 is preferably mounted on the cylindrical key 38.
• the end of the key 38 is slitted or slotted at 57 and the slot 57 extends down to end wall 58 at the bottom of the slot and against which is abutted the lower end 56 of the locator shim.
• the threads 50 in the end portions and in the cap 24 are sufficiently fine to provide a precise axial alignment of one half portion relative to the other.
• the threaded cap assembly allows simple and rapid substitution of the key 38.
• cap 24 has a vacant, hollow portion 24a at its outer end. This provides an added length to the instrument but does not increase the weight of the instrument significantly if the cap is made from any number of lightweight well-known materials, such as aluminum, for example.
• the cap 24 is threaded onto the axially and circumferentially aligned threads.
• portions of key 38 are always in engagement with the slots 40, 42, and a smooth, sliding action increases that engagement over the length of the key as the instrument is closed.
• an added degree of control can be provided by a protrusion 60 formed in half portion 20, mating with a complementary-shaped recess 62 formed in the other half portion 18. This feature provides transversely extending protrusions 60 straddling either side of key 38 adjacent its free end 38b.
• a second axially-adjacent pair of protrusions and recesses can be provided.
• a protrusion 64 is received in a complementary-shaped recess 66.
• Protrusion 64 is formed in half portion 18, immediately adjacent recess 62 so as to form a continuous S-shaped mating surface therewith.
• the recess 66 is formed in half portion 20 immediately adjacent protrusion 60 to form a continuous complementary-shaped S-shaped mating surface.
• the two half portions are identical except for a reversal of the configuration of these S-shaped mating surfaces.
• the shapes of the protrusions and recesses illustrated in the Figures approximate a "square-wave” they can be rounded at their peaks and valleys to approximate a "sine-wave” configuration.
• the protrusions and recesses can be generally triangular in shape. It is desired, however, that the tips of the protrusions be tapered to ensure a smooth release of one S-shaped mating surface from the other when the instrument is opened.
• the illustrated "square-wave" protrusion is preferably tapered to form a blunted point.
• the protrusions 60 and 64 may provide a constant continual engagement with the key 38 at their respective slots 40, 42, it being appreciated that the interior surfaces 60a (FIGS. 5 and 6) on the protrusions extend vertically as continuous extensions of the side wall forming the slot 42. Likewise, interior surfaces 64a on the protrusions 64 extend vertically as extensions of the side walls of the slot 40 to engage the key 38 at all times. Thus, the interior surfaces 60a and 64a each engage opposite sides of the key 38 when the instrument is fully opened as well as when fully closed and at positions therebetween.
• the slots 40 and 42 may be machined oversized at areas indicated by lines 42c and 42d in FIG.
• the lateral dimension of the space between the protrusions of a given half portion can be tapered in an outward direction to provide a "funneling" of the key into the slot, either 40 or 42.
• any such tapering is not provided, such funneling not being required as the key is constantly contained within the protrusions of one of the half portions, and preferably is always contained within the protrusions of both half portions.
• further weight reduction can be obtained by fashioning key 38 from hollow, tubular stock. All other features of alignment, particularly the smooth exterior, smooth rounded surface of the key extending into the smooth, rounded surface of the slots, is maintained.
• FIG. 5 illustrating the half portion 20 would be identical to a similar view of the half portion 18, but for an interchanging of its protrusion 64 and recess 62. That is, the shear tip 12 would be identical to that illustrated for the shear tip 14 at FIG. 5, the slot 40 would be identical to the illustrated slot 42, and all remaining of the half portion are identical except for the interchanging of the positions of the protrusion 64 and recess 62.
• the microsurgical instrument of the present invention permits extremely discrete cutting actions with precise finger pressure.
• the scissors instrument of the present invention is also ' fully compatible with other rotational neurosurgery techniques.
• a scissors instrument constructed according to the present invention is useful not only for cutting tissue, but for the frequently associated tasks of spreading tissues and dilating vessels.
• FIGS. 10 and 11 the second illustrated example 110 of the invention will be described.
• the forceps 110 according to the present invention is especially useful for microscopic surgery.
• a fine curved microsurgical needle can be distorted if it is roughly handled and that once distorted, it can no longer be used.
• the needles are difficult to grip by those who are not highly trained in microsurgery; and when a surgeon makes numerous stitches in a microsurgical operation, it is to be understood that an occasional needle may pop out of the grasp of the instrument and be lost with the instruments heretofore used.
• the microsurgeon with a conventional needle holder grasps the needle with his dominant hand, and with a forceps, such as shown in FIGS. 10 and 11 in his non-dominant hand, he then grasps a needle end with the forceps and rotates the needle point upward with the thread bearing end being likewise pointed upward. In this position, the needle point is ready to be rotated through a piece of tissue, such as a human vessel for anastomizing blood vessels together.
• the particular end uses of the microsurgical instrument of the present invention can vary considerably, and may take forms other than the scissors or forceps shown herein.
• Microinstruments of the present invention are adapted for use with rotational microsurgical techniques and are particularly advantageous in this regard. Further advantages, especially when grasping curved needles, are provided in the needle holder described below with reference to FIGS. 12-14. -22-
• the central portion of the forceps 110 will have the same protrusions (such as the illustrated protrusions 60 and 64) and the same slots (40 and 42) and use the same key (such as the key 38) . Because they already have been described, these keys, slots and protrusions will not be described again.
• the tips 112 and 114 of instrument 110 have points or ends 112a and 114a, respectively, as sharp and as pointed as needles, and the movements thereof are only about 0.2 inches or 5mm between opening and closing.
• the needles are so fine that if drawn to scale adjacent the points 112a or 114a the needles would appear only as a fine small line adjacent points 112a or 114a Movement of the needle as much as one inch moves the needle out of the field of view of the microscope; which typically provides 20x magnification.
• the points 112a and 114a of the instrument appear as needle sharp points to the naked eye and they usually are only in the range of 50 microns to 2mm in diameter, and form an angle of only a few degrees at their tip.
• any deflection laterally i.e., a twisting movement of only a few millimeters causes problems in properly gripping the needle. Since the points 112a and 114a are often five or six inches from the tip ends, the points have a long unsupported length that can lead to such deflections particularly when the surgeon is twisting the instrument, a maneuver frequently practiced in rotational microsurgery techniques. Because the points 112 and 114 on the ends of the microsurgical instrument 110 (Figs. 10 and 11) are so sharp, great precision of the planar closing movement is needed, more than with the macrosurgical tools of the prior art, especially since the microsurgical instrument is used under a 20x microscope.
• the alignment features, particularly the interengagement between key and slots of this embodiment are the same as described above in FIGS. 1-8.
• the preferred instrument shape is substantially cylindrical when the halves 118, 120 are brought together, so that the instrument may be rotated about its longitudinal axis. More specifically, the cylindrical central section of the instrument is laid along the middle finger of a hand resting on a surface to suppress tremors, and the thumb is rotated along the cylindrical surface to impart a spindle-like rotation to the instrument along its longitudinal axis on the middle finger thereby turning the tips through a natural arc of rotation to move a needle thread, etc. with a precise controlled movement.
• finger texturing is provided to assist the surgeon in maintaining precise control of the instrument, even while wearing conventional gloves adapted for surgery.
• finger texturing is provided by a series of spaced-apart cylindrical grooves 65 machined into the outer surface of the cylindrical body of the instrument.
• the finger texture grooves 65 are located at the location where the surgeon will grip the tool for turning and provide a non-slip surface.
• These spaced-inward grooves offer significant improvement over knurling in that the surgeon's gloves are not snagged or degraded by contact with the finger texturing, while an improved tactile engagement with the instrument is provided.
• the texturing is not shown in all figures for purposes of clarity. However, the preferred embodiments do, in fact, employ such texturing.
• the tips of the various embodiments of the instrument are very fine, and easily damaged. Accordingly, there is provided an arrangement for a removable and replaceable tip 114b as shown in FIGS. 12 and 13.
• the tip has a rectangular extension 170 at one end which fits into a slot 171 formed in the half 20.
• the groove 71 is rectangular in cross-section to prevent rotation of the tip.
• the associated tip would have a similar extension which would fit into a similar groove in the other half 118.
• Spring loaded balls 172 project from each side 173 of extension 170 and when seated onto the associated depressions 174 in the half 120 at the groove 171 lock the tip in place.
• Other locking means such as lock screws, roll pins, push button releases and the like could be used.
• End walls 175 on the tip are held in tight engagement with end walls 176 on the cylindrical portion when the tip is detented in position.
• the slot 142 preferably extends into the replaceable tip 146.
• a blank having a generally cylindrical body of titanium or 420 stainless steel is provided.
• the blank is cut by electrical discharge cutting means as are known in the art.
• the cutting operation is computer-controlled, and is performed principally by translating the cylindrical blank relative to the electrical discharge cutting means, which is aligned to travel from end to end along the axis of the blank.
• the long, needle-like tapered tip is machined at the leading end of the blank so as to provide a working tip for the instrument.
• the thread 50 and the finger texture grooves 65 are machined onto the blank before it is split in half.
• the preferred angle for each semiconical tip surface is 5° to give the typical surgeon the proper length of tip point from his fingers located at the textured grooves 65.
• a 4° taper provides a shorter, stubby point.
• the other, closed end is threaded to form the threaded portions 50; and a series of special finger texture grooves 65 (FIG. 1) are cut in circular shape and spaced longitudinally of each other on the outer cylindrical surface of the blank.
• the finger texture grooves may be extended down into the conical surface so that surgeons with a shorter finger grip may also grasp a textured surface.
• the cutting tips can be hardened to retain their sharpness.
• the 420 stainless material provides a tool having a 52 Rockwell hardness.
• titanium can be vapor deposited on the flat surfaces 12a, 14a, and the cutting edges 12c, 14c to further enhance wearability, and to obtain a 54 Rockwell hardness as measured on the "C"-scale.
• Other coating materials and hardening processes available today may also be used. After hardening, the two half portions are laid open and a precise milling operation is performed on each half portion to form the slots 40 and 42 therein.
• the slots 40 and 42 are precisely milled into the faces 30 and additionally, as best seen in Figure 5, other metal is removed about the slots 40 and 42 on opposite sides of the protrusions and recesses until the tool is at the precise weight desired to form the oversized areas 42c and 42d.
• the locator shim recesses 54 are also machined into each half. If the tool halves are made from a relatively soft material, such as injected plastic or die cast metal, usable surfaces at the cutting tips or other portions subject to wear may be provided by atomic deposition of titanium or any of the like commercially available coatings, after the half portions are formed and finished, as above.
• the width of material removed by the electrical discharge cutting apparatus is well known and carefully controlled throughout the cutting steps.
• the locator shim 53 having a width to compensate for the width of the electrical discharge cut is placed into the recesses 54 (Fig. 8) and the key 38 is placed into the slots 40 and 42.
• the cap 24 is then threaded onto threads 50 which are aligned in the axial direction by the shim.
• the preferred key 38 is a precision sized tube that has its outer wall oversized and then the tube exterior wall is centerless ground to provide a precise cylindrical surface of constant diameter throughout its length.
• a slot 57 is machined into one end of the key to receive the locator shim 53.
• the method of forming the surgical scissors is somewhat more complicated in that the scissors must be provided in the cutting operation.
• the cutting by the EDM apparatus preferably starts at the forward conical tip.
• the cylindrical blank is rotated or is generally spirally or helically displaced 90° in a counterclockwise direction (observed from the sharpened conical tip) and cutting along the axis of (now rotated) blank proceeds until the point of formation of the recesses 62, 66 and protrusions 60, 64 is approached.
• the blank is moved transversely of its axis in a first transverse direction and upon a slight additional axial displacement, the tip of a protrusion and a valley of a recess is formed.
• the blank is then displaced in an opposite transverse direction past the axis of the blank so that not only is the first set of protrusions and recesses completed, but the formation of the latter, downstream set of protrusion and recess configurations is initiated.
• a further slight axial displacement forms the peak and valley of the protrusion and recess.
• a final transverse displacement of the blank is performed until the electrical discharge cutting means is again aligned with the axis of the blank.
• the cut then proceeds along the axis of the blank until its reaches the area at which the windows 48 are to be cut.
• the cutting operation proceeds as before, and a loop cut is made to cut the window 48 from the metal blank and then the thread 50 is severed and then the two half portions are completely separated, one from another.
• the half portions are placed in a fixture and each is bent to a 10° angle at the thin window 48 sections so that tips are spaced 20° apart in their open position: manifestly, this degree of opening may be varied.
• the illustrated EDM gap or slot is about 0.015 inches, and to bring the scissor flat cutting faces 12 and 14 back into tight engagement, the halves are placed in a fixture and the halves are permanently deflected with the faces 12 and 14 in tight engagement and parallel to each other.
• the cutting edges 14c and 14d will likewise be closely adjacent to provide a tight shearing action.
• the precision bores 40 and 42 are not drilled into the stock, as a drill might wander and not provide the precision desired.
• the microsurgical tool may be formed with separate and replaceable tip and spring members which may be quickly detached from their respective holder bodies if a tip becomes damaged or if it is desired to use a different type of tip in the holder bodies.
• microsurgical instrument provides a unique alignment arrangement which maintains a precise fit of the instrument tips at all times, a feature which is essential to the delicate work of a microsurgeon.
• surgeon can employ rotational techniques which offer improved precision and control while facilitating the use of both dominant and non-dominant hands throughout the course of delicate surgical maneuvers.
• the microsurgical instrument of the present invention When utilized to provide a needle holder, the microsurgical instrument of the present invention provides improved setting of the surgeon's needle.
• the needles used in microsurgery to sew blood vessels together are curved, and are typically so small that they are difficult to see without magnification. Further, when these curved needles are grasped by conventional micro-needle holders, they frequently fall out of the jaws of the instrument or turn in an unintended direction. This requires the surgeon to employ a forceps in his non-dominant hand to bring the needle into the proper position. It will be appreciated that, throughout a lengthy operation, the constant repetition of this awkward and time-consuming two-handed technique is particularly undesirable.
• the microsurgical instrument of the present invention When configured as a needle holder, the microsurgical instrument of the present invention provides continuous engagement of the needle in the jaws or working area of the instrument, and maintains the rotational movement of the needle relative to the instrument, thereby automatically bringing the needle into proper position for suturing.
• FIGS. 12-16 two alternative embodiments of needle holders constructed according to the present invention are illustrated.
• the needle holders have major body portions substantially identical to those of the forceps and scissors instruments described above.
• each needle holder has two mating halves aligned with an internal key in their open and closed positions, and at all intermediate positions therebetween.
• the needle holders are conveniently provided with complementary mating protrusions and recesses, one on each body half-portion, to provide further alignment between the halves, as described above.
• FIGS. 12, 13 and 13a illustrate a needle holder of curved configuration
• the needle holder of FIGS. 14, 14a, 15 and 16 has a straight, or conoid outer configuration.
• curved, mating jaw portions provide improved control when grasping micro-needles.
• the pointed needle-grasping jaws of the instrument 210 of FIG. 12 are shown in the enlarged illustrations of FIGS. 13, 13a.
• the curved jaws comprise a portion of the interengaging tips 212,214 each of which extend from a respective body " half portion 218,220 of the needle holder instrument 210.
• FIG. 14 illustrates the second alternative, a "straight" configuration wherein conoid tips 312,314 extend from substantially identical half body portions, such as the body portions 218,220 of FIG. 12.
• FIGS. 14a, 15 and 16 are enlarged views of the curved jaw portion of FIG. 14 located adjacent the free ends of the tips. Engagement between the mating tips of the straight configuration of FIGS. 14-16 will be described first, it being realized that the arrangement of the tips of FIGS. 12-13a may be thought of, at least conceptually, as being formed by a gross bending of the instrument tips of FIGS. 14-16, with care being taken to compensate for the adjustment in length of the mating tips 212,214 caused by such bending.
• the mating tip portions 312,314 having curved, mating jaw-like surfaces 312a,314a formed by a precision, computer- controlled EDM cutting operation which cuts a solid conoid blank, as described above with respect to the other embodiments.
• the present invention provides curved mating surfaces 312a,314a composed of arcuate portions, the centers of which lie to one side of the instrument axis.
• the EDM cutting operation does not intersect the central or axial free end 320 of the instrument. Rather, cutting of the instrument blank is initiated at one side of the axial free end.
• Cutting follows a curved plane perpendicular to the instrument axis, to form curved mating surfaces 312a,314a that are simple curved surfaces and are not compound or complex curved surfaces as would be formed by twisting the instrument blank about its axis as the EDM cutting operation advances from one end of the blank to the other.
• tip portion 314 is longer than portion 312 and has a generally hooked-shape which overlies or completely covers the mating surface 312a of the other tip portion 312.
• the mating tip portions 312,314 form a slightly truncated conoid shape when mated.
• the shorter tip portion 312 and the longer tip portion 314 are formed to provide an intimate engagement over a working area 324 extending between the free ends 332,334 of the tip portions and a reference point 340 (see FIG. 15) remote from the instrument tip.
• a small gap 344 between the body portions extends from reference point 340 to the opposite end of the instrument (not shown) where the half portions are connected together, as by the threaded cap 24 described above with reference to FIG. 1.
• a needle holder instrument has an outside diameter of .32 inches along its cylindrical major body portion, and has a sharpened or conoid tip measuring 1.61 inches in an axial direction.
• the reference point 340 defining one end of working area 324, is located .160 inches in an axial direction, from tip 320 of the needle holder instrument.
• the radius of curvature of the mating surfaces 312a,314a is approximately 0.03 inches, and is offset .026 inches in an axial direction from the tip 320.
• the mating surfaces of the working area are provided with a series of serrations extending, with reference to FIG. 14, into the plane of the paper and have a depth ranging between one-half to one mil. Needles are preferably grasped in the anterior, curved portion or jaw of the working area, but may also be grasped in the straight, posterior portion of working area 324.
• the working area 324 and particularly the curved jaw portions 312a,314a thereof are extremely small, the entire working area comprising only approximately 10% of the axial length of the conoid tip of the instrument. If the conoid tip were fully developed so as to terminate at an infinitely sharp point, its axial length would be approximately 1.8 inches long, beginning at a base of 0.32 inches diameter where the conoid tip is joined to the remaining cylindrical body portion of the instrument.
• the preferred embodiment, as mentioned, is slightly truncated, with the instrument tip having a length of 1.61 inches.
• tip portions 212,214 are substantially identical to tip portions 312,314 discussed above, but for a bending of those portions along a common one inch radius, located approximately 1.2 inches in an axial direction from the base of the conoid tip. All other features of the tips 212,214 remain the same as described above for tips 312,314.
• the curved surfaces 212a,214a each have a 0.03 inch radius located approximately 0.026 inches posterior of the instrument tip 220.
• the curved portions 212a,214a form complementary-shaped interengaging arcuate surfaces, with the free end of the longer tip portion, namely, tip portion 214, overlying the free end of tip portion 212.
• the centers of curvature of the surfaces 212a,214a lie on the same side of the instrument, as does the one inch radius of curvature of the tip portions 212,214.
• the curved embodiment of FIGS. 12,13 increases the surgeon's field of view for positions of the instrument " commonly held during surgery. Also, it will be appreciated, that, when using the rotational technique described above, the tips of the straight and curved alternative embodiments of the needle holder will sweep different paths, each having their own distinctive advantages in the course of a microsurgical procedure.

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• 1987
  • 1987-03-12 WO PCT/US1987/000528 patent/WO1987005483A1/en not_active Application Discontinuation
  • 1987-03-12 EP EP19870902242 patent/EP0259482A4/de not_active Withdrawn

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