MXPA97002359A

MXPA97002359A - Procedure to clean water quirurgi

Info

Publication number: MXPA97002359A
Application number: MXPA/A/1997/002359A
Authority: MX
Inventors: Vetrecin Robert; Hersey Bruce
Original assignee: Ethicon Inc
Priority date: 1996-03-27
Filing date: 1997-03-26
Publication date: 1998-10-15

Abstract

A method for cleaning surfaces of a metal alloy surgical needle or a metal alloy surgical instrument, the method involves exposing the surfaces of a metal alloy surgical needle or a metal alloy surgical instrument to a gas plasma during enough time to effectively clean the surfaces of the needle or the instrument

Description

PROCEDURE PñRfl CLEAN SURGICAL WATERS TECHNICAL FIELD The scope of the technique to which this invention pertains is that of surgical needles. Particularly as a method to treat surgical needles and surgical needles produced by such method.

BACKGROUND OF THE INVENTION Surgical needles are typically made of wire, in particular, various conventional grades of stainless steel and equivalent alloys, which are resistant to corrosion and possess desired mechanical properties. Typical alloys include the types 420, 420F and 455 of stainless steels and titanium and nickel martensitic stainless steel alloys such as those described in the U.S. patent. No. 5,000,912 which is incorporated in the present by reference. The wire is typically received from the manufacturer wound on a reel. In a typical surgical needle manufacturing procedure, the wire is removed from the reel, straightened and then cut into needle pieces. The needle pieces are then subjected to a series of manufacturing steps in which the penetration points are engraved or formed, the suture mounting sections are perforated or formed and the needle is configured to have the final geometry that can include cutting edges, inclinations, curved sections etc. The methods for manufacturing surgical needles are described in the patent applications of E.U.A. copendien + is normally assigned serial no. 08 / 405,554 and 08 / 429,446, which are incorporated by reference. e knows that the wire used to make the needles has surface contaminants when it is received from the mill. In addition, additional surface contaminants can be lifted during the manufacturing process. These contaminants, which are well known in the art, may include conductive lubricants, processing lubricants, fats, oils, carbon, other hydrocarbon materials, and the like. Although existing cleaning procedures produce needles having properly cleaned surfaces, there are certain disadvantages associated with the use of these methods. The procedures may require the use of chemical bars, either aqueous or organic, generating both chemical gases and hazardous waste. Chemical baths have a limited life time and have to be discarded at a considerable cost. In addition, the use of the types of chemicals required for cleaning baths involves safety risks that must be constantly monitored. A further disadvantage of conventional cleaning procedures is that residues that come from cleaning baths or contaminants from manufacturing processes can be left on the needles or instruments, even after having repeated conventional cleaning cycles. Accordingly, there is a need in this technique for a novel method for cleaning surfaces of surgical needles and metal alloy surgical instruments without the use of chemical baths.

DESCRIPTION OF THE INVENTION It is an object of the present invention to provide a method for cleaning the surfaces of surgical needles and surgical instruments of metal alloy without the need for chemical baths. It is another object of the present invention to provide a method for cleaning the surfaces of needles or surgical instruments, which removes residual contaminants. Therefore, a method is described for cleaning a needle or surgical instrument made of metal alloy. The needle or surgical metal instrument has an outer surface and optionally an inner surface. The surfaces of the needle or surgical metal instrument are exposed to a gaseous plasma for a sufficient period of time at a temperature sufficient to effectively clean contaminants from the surfaces of the needle or instrument. Also another aspect of the present invention is a needle or surgical instrument cleaned by the procedure described above. The novel method of cleaning needles or surgical instruments of metal alloy of the present invention has many advantages. The environmental risks associated with the use of chemical baths are eliminated, every time these chemical baths are not necessary. In addition, gaseous plasma, which is used to clean the outer surface of surgical instruments and needles, can be recaptured and recycled after each procedure. In addition, the present plasma process produces needles having surfaces, which may be cleaner than the needles cleaned by conventional methods. The foregoing, as well as other features and advantages of the present invention, will be more apparent from the following description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 illustrates a flow chart for a cleaning process of the present invention.

BEST WAY TO CARRY OUT THE INVENTION Gases that can be used for the plasmas of the present invention include oxygen, helium, carbon tetrafluoride, nitrogen, argon and the like, as well as mixtures and equivalents thereof. It is particularly preferred to use mixtures of gases such as oxygen, helium and carbon tetrafluoride. When a mixture of oxygen, helium or argon and carbon tetrafluoride is used, sufficient quantities of each component will be used to provide an effective plasma mixture. Typically, about 502 to about 99% oxygen will be used in such a mixture, very typically about 60% to about 99%, and preferably about 70% to about 99%. Typical amounts of helium or argon that will be used in such a mixture will typically be from 1% to up to about 50%, very typically from about 10% to about 40% and preferably from about 10% to about 30%. Although it is not preferred, it is possible to use a mixture of helium and argon. The amounts of carbon tetrafluoride to be used in a preferred mixture will typically be from about 1% to about 40%, most typically about 15% to about 35%, and preferably about 10% to about 30%. The percentages used herein are percentages by weight. A particularly preferred cleaning mixture will use about 10% helium or argon, about 70% oxygen and about 20% carbon tetrachloride. A conventional unit for a plasma treatment process is typically used in the methods of the present invention. The plasma unit will typically have a volumetric chamber, which is capable of withstanding both pressure and vacuum. Mounted in the camera will be at least one electrode. A preferred unit is a Gasonics plasma unit manufactured by Gasonics / IPL, San TJose, California, however, any conventional unit or gas plasma equivalent may be used, as well as any primary or secondary discharge unit. A gas or gas mixture is typically brought to a plasma state in these units by exposing the gas to sufficient electromagnetic energy such as radio frequency electromagnetic waves, microwaves, etc., to effectively induce a plasma state. However, other means can be used to excite the gas in a plasma state, including direct current, laser energy, equivalents thereof and the like. If desired, the needles or instruments can be exposed to a conventional plasma torch. Sufficient electromagnetic energy will be applied to the gas to effectively produce a plasma condition. Typically the amount of energy used will be from about 250U (0.12 watts / M2) to about 2500U (1.2 watts / M2), very typically about 300W (.014 watts / M2) to about 1000U (0.46 watts / M2), and preferably about 400U (0.18 watts / M2) to approximately 900) (0.42 watts / M2). Of course, those skilled in the art will appreciate that the amount of energy used will vary according to the parameters of the process including the gas flow, the type of gas, the electrode and vacuum area, etc., as well as the type, size, condition and configuration of the plasma unit. The gas will flow into the plasma treatment process unit at a sufficient volumetric flow rate to effectively produce a plasma. The volume of the chamber of the unit will be sufficient to effectively contain the needles or instruments that are treated. These parameters will vary in accordance with the particular parameters of the process and are easily determined by those skilled in the art. A typical flow chart for a cleaning process of the present invention is illustrated in Figure 1, although those skilled in the art will appreciate that several steps can be eliminated or added to the methods of the present invention. As illustrated in Figure 1, the initial step of such a procedure is to load needles or surgical instruments 10 into a chamber 25 of a plasma treatment unit 20. Subsequently, a sufficient vacuum 30 is drawn into the chamber 25 to evacuate effectively air to the chamber and produce a vacuum sufficient to introduce the plasma. Typically, the vacuum will be between about 0.05 to about 1 Torr, very typically about 0.25 to about 0.75 Torr, and preferably about 0.3 to about 0.5 Torr, however this will vary with the type and configuration of the plasma unit used. Subsequently, the chamber 25 is filled with a gas or a mixture of gas 40 of choice, so that there is a sufficient quantity of gas 40 present in the chamber 25 to effectively form the gas plasma 50. Typically the flow velocity of the gas 40 used can be from about 50 to about 500 cc / rnin, very typically about 100 to about 500 cc / mm, and preferably about 200 to about 500 cc / rnin, however, this flow rate may vary depending on the type and configuration of the plasma unit used. Then, the power is turned on by energizing the power source 60 within the unit 20 and thus forming a plasma 50, and the needles or surgical instruments 10 are exposed to the gas plasma 50 for a period of time sufficient to effectively clean the surfaces of the plasma. the needles or surgical instruments 10. Typically the plasma cycle time can be from about 10 to about 60 minutes, very typically about 20 to about 40 minutes, and preferably about 30 to about 45 minutes, however, this will vary depending on the procedure cycle, the parameters of the procedure and the type and configuration of the plasma unit used. Subsequently, after the energy 60 has been turned off, the gas 40 is removed from the chamber 25 through the outlet 80 and the chamber 25 is again filled with an inert gas 70, such as nitrogen, and maintained at a Sufficient pressure for a sufficient amount of time to effectively cool the needles or instruments 10. For example, the needles may be maintained in the cooling phase for about 3 to about 10 minutes, very typically about 3 to about 7 minutes, and preferably about 3 minutes. to approximately 5 minutes. The pressure of the inert gas can be, for example, from about 0.05 Torr to about 1.0 Torr. Finally, the clean needles or instruments 100 are removed from the chamber 25 of the gas plasma unit 20. The gas 40 withdrawn through the outlet 80 can be recycled for use in the process. Surgical needles that can be cleaned using the method of the present invention include any conventional surgical needle having a point of penetration, tip or blunt and a suture mounting end. The suture mounting end may have a channel or a blind hole punched to receive sutures. Surgical instruments that can be cleaned using the method of the present invention include conventional instruments and parts thereof such as aug's fasteners, scissors, forceps, scalpels, catheters, cutting instruments, tweezers, saws and the like. The term "surgical instrument" as used herein is defined to include a metal part of a surgical instrument. The needles and instruments will have exterior surfaces and may have interior surfaces. The following example is illustrative of the principles and practice of the present invention.

EXAMPLE Approximately 30,000 surgical needles made of 420 stainless steel metal alloy were placed in a chamber of a TasomcsR plasma unit. The chamber had a volume of approximately 0.113 3. The door of the unit was sealed and the chamber was evacuated under a vacuum of approximately 0.15 Torr for about one minute to purge the volatiles and contaminants. The chamber was subsequently refilled with a mixture of 50 cc / minute of oxygen and 50 cc / rninute of helium at a pressure of about 0.3 to about 0.5 Torr. The gas mixture was maintained in the chamber before the power was turned on for approximately two minutes. Then, the power of the unit was turned on and the needles were exposed to the re-gassing plasma gas which was maintained at a power level of approximately 500 watts for about 30 minutes. Afterwards, the power was turned off and the gas mixture was evacuated from the chamber. The chamber was then filled with nitrogen and maintained at a pressure of about 1.0 Torr for about 3-5 minutes until the needles cooled sufficiently to be handled. The needles were then removed from the chamber of the gas plasma unit. Under inspection, the surfaces of the needles were cleaned. The method of the present invention for cleaning the surfaces of surgical alloy metal needles and instruments has many advantages. Surprisingly and unexpectedly, it is now possible to clean the surfaces of surgical alloy metal needles and instruments in a controlled procedure that does not use chemicals and that does not generate the vapors emissions and associated hazardous waste streams. Using the plasma process of the present invention, it is possible to recycle the gaseous plasma agents. Also another advantage of the present invention is that the needles that are processed in the gas plasma processes of the present invention are not subject to metal trailing, which is a disadvantage characteristic of chemical or electrochemical processes. Also another advantage of the method of the present invention is that it is significantly more economical and cost effective than conventional cleaning procedures of the prior art. The method of the present invention also eliminates the safety problems associated with conventional cleaning procedures. Also another advantage of the present invention is that the surfaces can be cleaned more effectively to remove more contaminants and remove debris than the prior art cleaning procedures to produce cleaning levels that had not previously occurred. Although this invention has been shown and described with respect to the detailed embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail thereof may be made without going beyond the spirit and scope of the invention. the claimed invention.,

Claims

NOVELTY OF THE INVENTION CLAIMS

1. - A method for cleaning the surface of a metallic surgical needle, the method consists of: exposing a metallic surgical needle having an exterior surface to a gaseous plasma for a sufficient period of time and a sufficient space to effectively clean the exterior surface of the needle.

2. The method according to claim 1, further characterized in that the gaseous plasma consists of a mixture of oxygen and helium and carbon tetrafluoride.

3. The method according to claim 1, further characterized in that the gaseous plasma consists of a mixture of oxygen, argon and carbon tetrafluoride.

4. The method according to claim 1, further characterized in that the plasma mixture consists of from about 50% by weight to about 99% by weight of oxygen, and about 1% by weight to about 50% by weight of helium and about 1% by weight to about 40% by weight of tetr carbon luoride.

5. The method according to claim 1, further characterized in that the metallic needle consists of an alloy selected from the group consisting of stainless steel T-420, stainless steel T-420F, stainless steel T-455 and alloy of martensitic stainless steel made of titanium nickel.

6. The method according to claim 1, further characterized in that the gaseous plasma is excited by an energy source, and further characterized in that said energy source consists of a member selected from the group consisting of radio, microwave and discharge frequency. DC.

7. The method according to claim 1, further characterized in that the plasma consists of oxygen.

8. A method for cleaning the surface of a metal surgical instrument, the method consists of: exposing a metal surgical instrument having an exterior surface to a gaseous plasma for a sufficient period of time and a sufficient surface area to effectively clean the surface outside of the instrument.

9. The method according to claim 8, further characterized in that the gaseous plasma consists of a mixture of oxygen and helium and carbon tetrafluoride.

10. The method according to claim 8, further characterized in that the gaseous plasma consists of a mixture of oxygen, argon and carbon tetrafluoride.

11. The method according to the claim 8, further characterized in that the plasma mixture consists of from about 50% by weight to about 99% by weight of oxygen, and about 1% by weight to about 50% by weight of helium and about 1% by weight to about 40% by weight. weight of carbon tetrafluoride.

12. The method according to claim 8, further characterized in that the metal needle consists of an alloy selected from the group consisting of stainless steel T-420, stainless steel T-420F, stainless steel T-455 and stainless steel alloy martensitic titanium nickel. 13.- The method according to the claim 8, further characterized in that the gaseous plasma is excited by an energy source, and further characterized in that said energy source consists of a member selected from the group consisting of radio frequency, icroonde and DC discharge. 14. The method according to claim 8, further characterized in that the plasma consists of oxygen. 15.- The method according to the claim 8, further characterized in that the instrument additionally consists of at least one inner surface and the inner surface is also cleaned. 16. The method according to claim 1, further characterized in that the needle additionally consists of at least one inner surface and the inner surface is also cleaned. 17. A surgical needle cleaned by the method according to claim 1. 18. A surgical instrument cleaned by the method according to claim 8.