EP1006906A1 - Electrosurgical instrument - Google Patents

Electrosurgical instrument

Info

Publication number
EP1006906A1
EP1006906A1 EP98902789A EP98902789A EP1006906A1 EP 1006906 A1 EP1006906 A1 EP 1006906A1 EP 98902789 A EP98902789 A EP 98902789A EP 98902789 A EP98902789 A EP 98902789A EP 1006906 A1 EP1006906 A1 EP 1006906A1
Authority
EP
European Patent Office
Prior art keywords
coating
electrosurgical
magnetite
instrument
electrode
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP98902789A
Other languages
German (de)
French (fr)
Other versions
EP1006906A4 (en
Inventor
Michael Henderson
Richard F. Jones
Nels Sorensen
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
MediCor Corp
Original Assignee
MediCor Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to US78381797A priority Critical
Application filed by MediCor Corp filed Critical MediCor Corp
Priority to PCT/US1998/000555 priority patent/WO1998030159A1/en
Publication of EP1006906A1 publication Critical patent/EP1006906A1/en
Publication of EP1006906A4 publication Critical patent/EP1006906A4/en
Priority to US783817 priority
Application status is Withdrawn legal-status Critical

Links

Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B18/00Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
    • A61B18/04Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating
    • A61B18/12Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current
    • A61B18/14Probes or electrodes therefor

Abstract

An exceptionally durable coating for electrosurgical instruments (10) is provided. This conductive coating (12) is composed of magnetite, Fe3O4, particles which are spraycoated onto the base metal (18) of a surgical instrument using a thermal spray technique.

Description

ELECTROSURGICAL INSTRUMENT

Field of the Invention

This invention relates to electrosurgical instruments and in particular to laparoscopic electrosurgical instruments. Background of the Invention

The use of high frequency electrical energy for surgical applications dates back almost a century. Electrosurgery is the generation and delivery of radio frequency current between an active electrode and a dispersive electrode to elevate the tissue temperature for cutting, coagulating, fulgurating, and dessicating. Electrosurgical energy is the most commonly used energy source in the discipline of surgery. In open surgery such as laparotomy, the surgeon has a wider vantage point in controlling bleeding and dissection, and has more options to complement his or her surgical technique. In laparoscopy and other closed procedures, precise delivery of electrosurgical energy is a requirement for optimizing surgical outcomes.

Historically, there have been difficulties with the use of electrosurgical instruments for cutting and coagulating tissues. For example, the working surfaces of the electrodes of such instruments tend to stick to tissue that comes in contact therewith. Also numerous incidents of inadvertent electrical shocks and burns to the patient and the physician, and even death to the patients have been reported. In a great number of these cases, the cause of the reported injury was specified as resulting from the breakdown of insulation of the electrosurgical instrument .

Numerous methods exist for providing an inert electrode working surface for electrosurgical instruments. The most common is the application of a non-stick coating to the base metal which usually is stainless steel, but could be aluminum or other metals. The typical non-stick coating is also an insulation material and thus cannot be applied to the working surface of the electrode portion of the instrument. Illustrative of such non-stick coatings are a fluorocarbon such as a poly (tetrafluoroethylene) , a poly(vinyl chloride) (PVC) , or a heat-shrinkable plastic. While these materials have well-documented electrical insulative characteristics, they are not optimally suited for use in electrosurgial instruments. The major weaknesses of the previously noted non-stick coatings are inadequate abrasion resistance (i.e., the coating rubs off easily leaving bare metal exposed) , decomposition of the coating at the relatively high temperatures used in sterilization and in the electrosurgical process itself, as well as retention of moisture between the coating and the stainless steel instrument . This retention of moisture can ultimately cause corrosion of the instrument and can also result in inadequate sterilization of the instrument. These problems necessitate the continual replacement of the current types of insulation used in electrosurgical instruments today with an attendant escalation of the costs of health care.

A suitable insulating ceramic coating is described in commonly owned U.S. Patent No. 5,562,659 to Morris .

The present invention provides a substantially non-stick working surface for an electrosurgical electrode by a conductive but inert iron oxide surface. The iron oxide coating is durable, heat resistant, and is easily cleaned. Moreover, the present coating is not susceptible to damage or erosion from thermal stresses derived from sterilization processes or high frequency electrical current when in use . Summary of the Invention

A laparoscopic electrosurgical instrument having a conductive magnetite (Fe304) coating on a metal substrate that serves as a working surface of an electrode is provided. A stainless steel substrate is a preferred electrode surface, but other metals such as aluminum can also be utilized to provide a working surface. The magnetite coating can be up to about 0.01 inch (about 0.25 mm) thick, and can be applied to the metal substrate using a thermal spray process such as is available from a plasma gun, a detonation gun, a high velocity oxygen fuel (HVOF) system, a high energy plasma (HEP) system, or the like.

Brief Description of the Drawing In the drawing,

FIG. 1 is a fragmentary view, partly in section, of an electrosurgical instrument provided with a coating of magnetite, Fe304/ on a working surface of the electrode portion of the instrument . Description of the Preferred Embodiments

Through utilization of a thermal spray process implemented by a plasma gun, a detonation gun, a high velocity oxygen fuel system, a high energy plasma system, or the like for the deposition of a magnetite coating, a high quality non-stick working surface for electrosurgical instruments can be realized. Such a coating is readily cleanable and also provides exceptional wear and abrasion characteristics, including being resistant to scratching, nicking or cutting. In addition, such coating is chemically inert, non-toxic, non-irritating and otherwise suitable for use in the human body. Deposition of the magnetite coating using the aforementioned thermal spray techniques promotes good adhesion of the coating to the base metal of the instrument, thereby minimizing a likelihood of corrosion and permitting steam and chemical sterilization without difficulty. The magnetite coating is easily applied to various shapes and sizes of instruments by thermal spraying and is cost effective.

The preferred material for the working surfaces of an electrosurgical instrument is a coating of magnetite, Fe304, with a thickness in the range of about 0.001 to about 0.01 inches (about 0.025 mm to about 0.25 mm) . A more preferred coating thickness is in the range of about 0.001 to about 0.004 inches (about 0.025 mm to about 0.1 mm) . Relatively thinner or thicker magnetite coatings can also be applied if indicated by a specific use.

Referring to FIGURE 1, a portion of a typical electrosurgical electrode 10 suitable for laparoscopic use is depicted. Electrode 10 is shown with a hook tip; however, other tip configurations such as a knife tip, cone tip, button tip, spatula tip, sling tip, scissor tip, forcep tip, and the like, are also available. The tip configuration of the electrosurgical instrument forms no part of the present invention.

Magnetite coating 12 is provided on the conductive tip portion 14 of electrode 10. The insulating layer 16, typically a ceramic material such as an alumina composite, or the like, surrounds electrode 10 except for the conductive tip portion 14 and necessary connections to a radio frequency (RF) current source. Shaft 18 of electrode 10 is typically made of surgical grade stainless steel . Hook portion 14 is unitary with shaft 18, defines the working surface of electrode 10, and is also made of stainless steel which provides the substrate for magnetite coating 12. The present invention is further illustrated by the following examples which demonstrate the magnetite coating for electrosurgical instruments.

EXAMPLE 1 : Conductive Magnetite Coating for

Electrosurgical Instruments

The following table, Table I, lists the chemical analysis of a typical lot of magnetite, Fe304, coating. The particle size of the black oxide is -32/+10 micron. This coating was applied to a steel substrate with a plasma gun to a thickness of about 0.003 inches

(0.08 mm) and was found to be a conductive coating.

TABLE I CHEMICAL ANALYSIS OF MAGNETITE POWDER

ELEMENT/COMPOUND PERCENT BY WEIGHT

Iron (Fe304) 70.5

Silica (Si02) 0.740 Titanium (Ti02) 0.112

Aluminum (Al203) 0.105

Calcium (CaO) 0.150

Magnesium (MgO) 0.044

Sodium (Na20) 0.214 Potassium (K20) 0.033

EXAMPLE 2: Comparative Performance of

Coated Electrodes Spatula-tip electrosurgical electrodes having a stainless steel working surface were provided with surface coatings of various compositions. These electrodes were then evaluated at 500 KHZ, and various power settings for ease of use and for cleanability. Contact time prior to the onset of electrode sticking to tissue was also noted. The observed results are presented in Table II, below. TABLE II NON-STICK TRIAL MATRIX

1

Abbreviations in Table II: ss-stainless steel

WC & Co-tungsten carbide & cobalt slt-slight hvy-heavy mod-moderate scr-only by scraping esy-easy imp-impossible imd-immediate n/a-not applicable s- seconds

The foregoing specification is intended to illustrate the present invention but is not to be taken as limiting. Still other variations within the spirit and scope of the present invention are possible and will readily present themselves to those skilled in the art .

Claims

WE CLAIM :
1. An electrosurgical instrument comprising: (a) a metal electrode having an exposed working surface; and (b) a conductive magnetite coating on the working surface of the metal electrode.
2. The instrument of claim 1 wherein the thickness of the coating is in the range of about 0.001 to about 0.01 inches.
3. The instrument of claim 1 wherein the thickness of the coating is in the range of about 0.001 to about 0.004 inches.
4. The instrument of claim 1 wherein the metal electrode is stainless steel.
EP98902789A 1997-01-13 1998-01-13 Electrosurgical instrument Withdrawn EP1006906A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US78381797A true 1997-01-13 1997-01-13
PCT/US1998/000555 WO1998030159A1 (en) 1997-01-13 1998-01-13 Electrosurgical instrument
US783817 2001-02-13

Publications (2)

Publication Number Publication Date
EP1006906A1 true EP1006906A1 (en) 2000-06-14
EP1006906A4 EP1006906A4 (en) 2000-06-14

Family

ID=25130482

Family Applications (1)

Application Number Title Priority Date Filing Date
EP98902789A Withdrawn EP1006906A1 (en) 1997-01-13 1998-01-13 Electrosurgical instrument

Country Status (5)

Country Link
EP (1) EP1006906A1 (en)
JP (1) JP2001507978A (en)
AU (1) AU5959798A (en)
CA (1) CA2277122A1 (en)
WO (1) WO1998030159A1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080234672A1 (en) * 2007-03-20 2008-09-25 Tyco Healthcare Goup Lp Non-stick surface coated electrodes and method for manufacturing same
US8523850B2 (en) * 2009-04-17 2013-09-03 Domain Surgical, Inc. Method for heating a surgical implement

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03229888A (en) * 1990-02-05 1991-10-11 Tokai Carbon Co Ltd Production of electrode coated with magnetite
US5330471A (en) * 1991-06-07 1994-07-19 Hemostatic Surgery Corporation Bi-polar electrosurgical endoscopic instruments and methods of use

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
No further relevant documents disclosed *
See also references of WO9830159A1 *

Also Published As

Publication number Publication date
AU5959798A (en) 1998-08-03
JP2001507978A (en) 2001-06-19
WO1998030159A1 (en) 1998-07-16
EP1006906A4 (en) 2000-06-14
CA2277122A1 (en) 1998-07-16

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