US-12622742-B2 - Electrosurgical instrument

US12622742B2US 12622742 B2US12622742 B2US 12622742B2US-12622742-B2

Abstract

An improved electrosurgical instrument, specifically a scissor style vessel sealer, comprising two overmoulded jaws formed from a structural polymer held in place by a pivot pin. The moulded structural polymer replaces many metal components which would otherwise be required for such an assembly. Not only does the use of the moulded structural polymer simplify the assembly of the instrument, it also enables the following additional functionality: moulded pivot holes, flanges providing lateral support, and a flexible lever arm which is designed to provide the force needed to clamp and seal vessels.

Inventors

Marno NAGTEGAAL

Assignees

GYRUS ACMI, INC

Dates

Publication Date: 20260512
Application Date: 20220302
Priority Date: 20210312

Claims (13)

1 . An electrosurgical instrument, comprising: a first component comprising a distal first jaw member, a first central section and a proximal first arm, the first component being formed from a first single piece of polymer material; a second component comprising a distal second jaw member and a second central section, the second component being formed from a second single piece of polymer material, wherein: the second central section is connected to a proximal second arm; the first and second components are pivotably connected such that at least one of the proximal first and second arms is movable with respect to the other of the proximal first and second arms between an open position in which the proximal first and second arms are spaced one from another and a closed position in which the proximal first and second arms are brought closer together, the distal first and second jaw members being moveable between first and second conditions in response to relative movement of the at least one of the proximal first and second arms; and at least the proximal first arm is formed of a shape and thickness of the polymer material such that it flexes past a certain application force, the polymer material having a flexural strength of at least 200 MPa and a cross-sectional area of 30-50 mm 2 , a cross-section of the first arm being taken perpendicular relative to a length of the first arm, whereby in use the distal first and second jaw members provide a clamping force to clamp a vessel held between the distal first and second jaw members, the flexing of the proximal first arm past the certain application force preventing excess clamping force being applied to the vessel.
2 . An electrosurgical instrument according to claim 1 , wherein a flexibility of the proximal first arm is selected such that the clamping force is within a predetermined range.
3 . An electrosurgical instrument according to claim 1 , wherein: at least one of the distal first and second jaw members comprises an electrically conductive sealing surface for communicating RF energy through tissue held therebetween; at least one of the proximal first and second arms comprises radio RF electrical connections capable of connecting the electrically conductive sealing surface to a source of RF energy.
4 . An electrosurgical instrument according to claim 1 , wherein at least one of the proximal first arm and the proximal second arm comprises a finger loop.
5 . An electrosurgical instrument according to claim 1 , wherein the first and second components are slotted together such that the second component slots through an opening in the first central section of the first component.
6 . An electrosurgical instrument according to claim 5 , wherein: an opening of the first central section of the first component is defined by first and second flanges, and the second central section of the second component is held in the opening of the first central section of the first component, the second central section of the second component being supported by the first and second flanges.
7 . An electrosurgical instrument according to claim 6 , wherein the first and second components are pivotably connected using a pivot pin.
8 . An electrosurgical instrument according to claim 7 , wherein: the pivot pin threads through a first pivot hole in the first flange; a second pivot hole in the second central section of the second component; and a third pivot hole in the second flange.
9 . An electrosurgical instrument according to claim 1 , wherein the first and second components are pivotably connected using a pivot pin.
10 . An electrosurgical instrument according to claim 1 , further comprising an activation button operable to deliver a source of radio frequency (RF) energy to at least one of the distal first and second jaw members.
11 . An electrosurgical instrument according to claim 1 , wherein the distal first and second jaw members comprise a pair of bipolar forceps.
12 . An electrosurgical instrument according to claim 1 , wherein: the first single piece of polymer material and the second single piece of polymer material are formed from a structural polymer overmould having at least 50% glass fiber therein.
13 . An electrosurgical system, comprising: an RF electrosurgical generator; and an electrosurgical instrument, comprising: a first component comprising a distal first jaw member, a first central section and a proximal first arm, the first component being formed from a first single piece of polymer material; a second component comprising a distal second jaw member and a second central section, the second component being formed from a second single piece of polymer material, wherein: the second central section is connected to a proximal second arm; the first and second components are pivotably connected such that at least one of the proximal first and second arms is movable with respect to the other arm between an open position in which the proximal first and second arms are spaced one from another and a closed position in which the proximal first and second arms are brought closer together, the distal first and second jaw members being moveable between first and second conditions in response to relative movement of at least one of the proximal first and second arms; and at least the proximal first arm is formed of a shape and thickness of the polymer material such that it flexes past a certain application force, the polymer material having a flexural strength of at least 200 MPa and a cross-sectional area of 30-50 mm 2 , a cross-section of the first arm being taken perpendicular relative to a length of the first arm, whereby in use the distal first and second jaw members provide a clamping force to clamp a vessel held between the first and second jaw members, the flexing of an at least first arm past the certain application force preventing excess clamping force being applied to the vessel.

Description

TECHNICAL FIELD Embodiments of the present invention described herein relate to an electrosurgical device, and in particular a scissor action vessel sealer. BACKGROUND TO THE INVENTION AND PRIOR ART Electrosurgical instruments provide advantages over traditional surgical instruments in that they can be used for coagulation and tissue sealing purposes. Electrosurgical forceps are used to clamp tissue or vessels before cutting and/or sealing the tissue by delivering a coagulation RF signal to one or more electrodes located at the end of the instrument. Vessel sealers currently on the market have a lot of assembly complexity both in terms of the number of components and the materials used to assemble a pair of jaws. Specifically, scissor style vessel sealers on the market use a combination of materials and components to form the jaw and lever arm assemblies. These assemblies involve a lot of metal components which are expensive, require various manufacturing and bonding techniques, as well as insulation from the electrodes. These assembly costs are typically very high due to the many components used. SUMMARY OF THE INVENTION Embodiments of the present invention provide an electrosurgical instrument, specifically a scissor style vessel sealer, comprising two overmoulded jaws formed from a structural polymer held in place by a pivot pin. The moulded structural polymer replaces many metal components which would otherwise be required for such an assembly. Not only does the use of the moulded structural polymer simplify the assembly of the instrument, it also enables the following additional functionality: moulded pivot holes, flanges providing lateral support, and a flexible lever arm which is designed to provide the force needed to clamp and seal vessels. No metal reinforcement components are required within the lever arm. Accordingly, in a first aspect, an electrosurgical instrument is provided, comprising: a first component comprising a distal first jaw member, a first central section and a proximal first arm, the first component being formed from a first single piece of polymer material; a second component comprising a distal second jaw member and a second central section, the second component being formed from a second single piece of polymer material, wherein the central section is connected to a proximal second arm. The first and second components are pivotably connected such that at least one of the first and second arms is movable with respect to the other arm between an open position in which the arms are spaced one from another and a closed position in which the arms are brought closer together, and the first and second jaw members being moveable between first and second conditions in response to the relative movement of the at least one arm. At least the first arm is arranged in use to provide a clamping force to clamp a vessel held between the first and second jaw members, the first arm being flexible past a certain application force. The above aspect is advantageous as using the polymer overmould replaces many metal components which would otherwise be necessary for such an assembly. Metal components are expensive, require various manufacturing and bonding techniques, and require insulation from electrodes. Using metal components results in high assembly costs due to many components being used. There is no exposed metal within this instrument, apart from the pivot pin and electrodes. The use of the polymer material greatly reduces the complexity of the instrument, reduces the part count and hugely simplifies the assembly. Using polymer material has further advantages of providing the additional functionality of moulded pivot holes and a flexible lever arm with an integral finger loop. The flexibility of the lever arm can be specially tuned to provide the correct clamping force for clamping and sealing vessels. The correct clamping force is achieved by the lever arm being flexible past a certain application force. As such, if a user applies a great application force which would ordinarily be above the predetermined acceptable range for clamping and/or sealing vessels, the lever arm flexes. This flexing of the lever arm results in the excess force being dissipated, the remaining force is transferred to the jaws such that the correct clamping/sealing force is applied to the vessels/tissue. There are no metal reinforcement components required for the lever arm. The tuning of the flexibility of the lever arm is achieved by designing the thickness of the material that forms the arm to give the desired flexibility, in that the thicker the material the less flexible it will be and the greater force will be transferred to the jaw members before the arm flexes. Both the width and height thickness dimensions may be modulated to give a desired flexibility response. In some embodiments, a flexibility of the first arm is selected such that the clamping force is within a predetermined range. In some embodiments, at