Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • 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
  • A61B17/28—Surgical forceps
  • A61B17/29—Forceps for use in minimally invasive surgery
  • A61B17/2909—Handles
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • A61B17/32—Surgical cutting instruments
  • A61B17/320016—Endoscopic cutting instruments, e.g. arthroscopes, resectoscopes
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • A61B17/28—Surgical forceps
  • A61B17/29—Forceps for use in minimally invasive surgery
  • A61B17/2909—Handles
  • A61B2017/2912—Handles transmission of forces to actuating rod or piston
  • A61B2017/2923—Toothed members, e.g. rack and pinion

Definitions

• This invention relates to microsurgical instruments for performing fine surgical tasks. More particularly, the invention relates to a microsurgical scissors with combined rotary action and axial biasing action for improving shearing action and durability.
• microsurgery requires precision instrumentation for special surgical tasks
• instrument designers and .manufacturers face special problems.
• the microsurgical instrument must typically perform a delicate surgical task. Often it must be inserted into a small, relatively inaccessible area without itself causing trauma or displacing the position of tissues in the operating field. Because microsurgery demands the surgeon's concentrated attention, the surgical instrument must also operate simply and effectively to facilitate rather than complicate the surgeon's work.
• the microsurgical instrument must not only perform its delicate operating task, but must also maintain its structural integrity. Because the instrument must be repeatedly used, its ability to maintain the proper relationship of its working parts helps to reduce hospital costs for replacing these expensive precision instruments.
• microsurgical scissors One such instrument is a microsurgical scissors.
• the required characteristics of an ideal microsurgical scissors are illustrated by its use in arthroscopic surgery of the knee for repair of damaged meniscus pads.
• the operation typically uses the double-puncture technique in which two or more portals of entry (for example, anteromedial and anterolateral portals for repairing meniscus tears) allow athroscopic viewing and dissection through one portal and retraction of loose or excised bodies through the second portal. Because this microsurgical procedure allows repair of the meniscus by a precision instrument as opposed to requiring partial or total removal as in arthrotomy, traumatic effects can be avoided.
• the recovery period of an arthrotomy is measured in weeks and months, and the affected muscles, bones and skin may exhibit quadriceps inhibition, patellofemoral imbalance and painful scars, respectively.
• Microsurgical procedures have been developed to redress these problems.
• the procedures use instruments that can reach the site of the operation through small incisions and with minimal displacement of intervening tissues.
• the working parts of one of these instruments e.g. the blades of a scissors, are small and are positioned on the forward end of a narrow shaft that extends through a small portal of entry from the exterior.
• the control elements of the instrument e.g. the handles of a scissors, which connect with the working parts through a linking rod within or adjacent to the shaft.
• the working elements of the microsurgical scissors must be approximately 3-5 millimeters in diameter to be inserted through a small operating portal of entry.
• the scissors For successful surgery, the scissors must cut surely • and precisely. To do so, the scissors must require only a small hand movement by the surgeon and must translate that movement to the shearing blades without altering their position in the operating field. In response, the faces of the blade must cooperate to cleanly shear, rather than tear, the meniscus.
• microsurgical scissors To be practical, the microsurgical scissors, must also endure post-operative cleaning, sterilizing and storing without sustaining debilitating damage. This lessens the expense of replacing the instrument and contributes to the success of the surgery by eliminating damaged instruments that complicate the surgeon's task. Particularly, the blades must continue to cooperate in their original, precise shearing relationship.
• Prior microsurgical scissors have presented problems to surgeons. A number of instruments are illustrated by Rand in “Microneurosurgical Instrumentation," Microneurosurgery (1978); and by O'Connor, "Arthroscopic Surgery of the Knee,” Arthroscopy and arthrography of the Knee (1978). Other instruments are shown by White et al. (U.S. Patent No. 3,834,021), Wallace (U.S. Patent No.
• prior art microsurgical scissors sometimes disassemble during an operation. If the pivot pin disengages from its position, a blade can fall from the instrument into the operating area, necessitating an independent recovery procedure.
• the principal object of this invention is a microsurgical instrument that will perform fine surgical tasks and withstand wear and damage.
• a further object is to provide a clean, sure, and precise shearing microsurgical scissors that can be inserted into a relatively small field of operation without undue tissue trauma or disruption.
• Another object is to provide such a microsurgical scissors that maintains its structural integrity and sustains minimal injury from mishandling.
• This invention achieves the above and further objects in a microsurgical instrument that uses rotary motion of a rod within a shaft for rotating a working part on the forward end of the rod into a functioning relationship with a working part on the forward end of the shaft.
• the invention also provides locking means associated with the handle of the instrument for maintaining the element on the forward end of the rod and shaft in a closed position.
• a microsurgical scissors uses rotary motion of a rod within a shaft for rotating a blade on the rod past a blade on the shaft in a shearing relationship, and also uses rearward tension of the rod with respect to the shaft for bearing the rod blade against the shaft blade as the rod blade rotates past in a shearing relationship.
• the rotatable rod lies within the tubular shaft, the rod and shaft each having a blade on its forward end.
• Actuating means associated with the handle rotates the rod, and thereby rotates the rod blade past the shaft blade.
• the rod blade is angled with respect to the shaft blade so that the blades intersect at at least one point of contact when the rod blade passes the shaft blade in a shearing relationship.
• Biasing means continuously bears the rod blade against the shaft blade at the point of contact as the rotating rod blade causes the point of contact" to travel.
• Figure 1 is a pictorial view of a microsurgical scissors with the blades in an open position.
• Figure 2 is a fragmentary side view with a partial cutout showing the relationship of certain parts within the handle.
• Figure 3 is another side view showing the relationship of the rack and pinion in the closed positions.
• Figure 5 is a view of the blades showing * their relationship in the open position.
• Figure 6 is a view of the blades showing their conformation in a preferred embodiment.
• Figure 1 illustrates an exemplary microsurgical scissors that incorporates this invention. It includes a handle 10 for gripping the instrument, a tubular shaft 11 that extends forward from the handle, rod, a shaft blade 13 affixed to the forward end of the shaft 11 and a rod blade 14 affixed to the forward end of a rod 12 disposed within the shaft 11.
• the user compresses a slotted sleeve 10A in the handle 10 against a base 10B. This impacts a rotary motion to the rod 12, thereby moving the rod blade 14 in an arcuate path past the shaft blade 13. This relative movement of the two blades provides the shearing action of .the scissors.
• handle 10 includes substantially rectangular base 10A and sleeve 10B that fits over and accommodates base 10A.
• a tublar slot 15 runs longitudinally and substantially centrally through base 10A for accommodating the rearward extension of shaft 11 and rod 12.
• a biasing means that includes spring 16 and compressing element 19.
• Spring 16 encircles the rearward end of rod 12.
• Compressing means 19 is a nut-like element that forces spring 16 against the base 22 of the shaft. While the spring is in the compressed position, compressing means 19 is fastened into position, for example, by tightening a radially extending screw that engages the rod. This produces rearward tension on the rod with respect to the shaft, and thereby causes blade 14 on the forward end of the rod to continuously bear against blade 13 on the forward end of the shaft.
• a pinion 23 is connected to the rod 12 such that rotary motion of the pinion 23 produces rotary motion of the -' rod 12, and arcuate motion of rod blade 14 with respect to shaft blade 13.
• a side opening 24 in the base 10A that exposes the teeth of pinion 23.
• a rack 25 ( Figures 2 and 4) that engages the teeth of the pinion.
• base 10A and sleeve 10B are connected by a pivot pin 26 that frictionally fits within a hole 27 in the sleeve 10B and a slot 31 in the base 10A.
• pivot pin 26 When sleeve 10B is depressed, it pivots on pivot pin 26 from an open to a closed position and carries the rack 25 transversely .with respect to the axis of rod 12. As it does, the teeth on the rack move into engagement with the teeth on pinion 23. The rod then rotates as sleeve 10B is .further depressed to its complete closing position. As the rod rotates in response to actuation of the handle 10, the working element on the forward end of the rod, namely blade 14, rotates past stationary shaft blade 13.
• the opening 24 in base 10A is shaped like an inverted L with a vertical portion 24A and horizontal portion 24B.
• the shearing edges 13A and 14A of the blades are angled with respect to each other in the direction of relative movement of the blades, e.g. the circumferential direction, so that the edges intersect each other when viewed in the radial direction and the point of intersection moves from one end of the blades to the other as the inner, rod blade 14 moves past the outer, shaft blade 13. Moreover, the blades make different angles with respect to the axis of the rod 12. Specifically, in the illustrated scissors, the rod blade 14 is tilted outward with respect to the axis a greater extent than the shaft blade 13. Thus, the rearward pull on the rod 12 executed by the pring 16 ( Figure 2) causes the shearing edge 13A to bear against the edge 14A at the point of intersection.
• the scissors thus provides a highly efficient shearing action in response to rotation of the rod 12 by actuation of the handle 10.
• FIGs 5 and 6 further show that blades 13 and 14 are arcuate about the center of rotation of the rod. That is, the inner face 34 of shaft blade 13 and the outerface 35 of the rod blade 14 are formed to nest as the rod blade rotates through the shearing stroke. This facilitates non-interfering relative movement of the two blades.
• a microsurgical instrument that performs precise surgical tasks and endures wear and handling.
• the drawing depicts a particular configuration of working elements for a microsurgical scissors.
• a microsurgical instrument such as a forceps could embody the same handle for gripping and actuating the instrument, the tubular shaft with a surgical gripping element on the forward end of the shaft, the rotatable rod with an opposing surgical gripping element on its forward end.
• Such a forceps might also include the locking means shown in Figures 2 and 4 for maintaining the gripping elements in closed relationship, as has been described. Therefore, we week to cover in the appended claims all such variations and modifications that come within the true spirit and scope of this invention.

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• Health & Medical Sciences (AREA)
• Surgery (AREA)
• Life Sciences & Earth Sciences (AREA)
• Medical Informatics (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Engineering & Computer Science (AREA)
• Biomedical Technology (AREA)
• Heart & Thoracic Surgery (AREA)
• Pathology (AREA)
• Molecular Biology (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Surgical Instruments (AREA)
• Scissors And Nippers (AREA)

Applications Claiming Priority (2)

Publications (2)

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Family Applications (1)

Country Status (5)

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Citations (7)

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• 1981
  • 1981-05-04 JP JP56501792A patent/JPS57500770A/ja active Pending
  • 1981-05-04 GB GB8200020A patent/GB2086233A/en not_active Withdrawn
  • 1981-05-04 EP EP19810901450 patent/EP0052631A4/en not_active Withdrawn
  • 1981-05-04 WO PCT/US1981/000598 patent/WO1981003122A1/en not_active Ceased
  • 1981-12-29 SE SE8107828A patent/SE8107828L/ not_active Application Discontinuation

Patent Citations (7)

Non-Patent Citations (1)

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