MXPA97002360A - Procedure to ennegrecer aguas quirurgi - Google Patents

Abstract

A procedure for blackening the surfaces of a metal alloy surgical needle or a metal alloy surgical instrument. The procedure consists of exposing the surfaces of a surgical needle or surgical instrument of metal alloy to a gaseous plasma for a sufficient time to effectively blacken the surfaces of the needle or instrument.

Description

PROCEDURE FOR ENGAGING SURGICAL WATERS TECHNICAL FIELD The field of the technique to which this invention belongs is that of surgical needles, very specifically a method for blackening surgical needles.

BACKGROUND OF THE INVENTION Surgical needles are typically manufactured from various types of steel alloys that do not corrode when the needles are exposed to environmental conditions after manufacture and before and during use. Metal alloys can be characteristic among stainless steels of the series of types 300 and 400 and other conventional alloys such as types 455, 420 and 420F, and the like. To "Jemas," rnartensitic stainless steel alloys containing nickel and titanium are used such as those described in US Pat. No. 5,000,912 which is incorporated by reference. Surgical needles and methods for manufacturing surgical needles are described in the commonly assigned numbers of US patent application Nos. 08 / 405,554 and 08 / 429,446 which are incorporated by reference. In certain surgical procedures, it is preferred to use the surgical needles having the blackened outer surface than the needles having the glossy glossy surface. It is believed that the blackening is caused by a formation and rust on the surface of the needle or metal alloy instrument. There are a number of known conventional methods for blackening stainless steel alloys and other conventional metal alloys including various chemical and electrochemical processes. The procedures for blackening surgical needles are described in U.S. Patent Nos. 4,959,068 and 4,905,695 which are incorporated by reference. The conventional blackening procedures that are most typically used are a chemical treatment of blackening and an electrochemical treatment. The treatment < * uimics uses mixtures of acids and aqueous salts to oxidize the surface of the surgical needle thereby producing a rusty layer and blackening the needle. For example, a characteristically used chemical mixture contains eulfauric acid and chromate, and potassium in an aqueous bath. The aqueous bath is preferably maintained at room temperature a? N «} ? ee can use other temperatures. Another type of blackening treatment is an electrochemical process. In an electrochemical blackening process, the needles are placed in a chemical bath and an electric current is passed through the bath. Such eletrochemical methods typically utilize voltages on the scale of, for example, 30 volts to approximately 150 volts and high amperages in the range of, for example, about 5 amperes to approximately 175 5 amperes. Although the existing electrochemical and chemical blackening procedures produce needles that have "blackened" surfaces, there are certain disadvantages with the use of these procedures. The procedures require the use of chemical baths that generate both chemical fumes and hazardous waste. Chemical baths have a limited usable duration and have to be disposed of at a considerable cost. In addition, the use of the types of chemical substances required for chemical baths or electrochemicals have concomitant safety risks that must be constantly monitored. Also, the electrochemical process uses relatively high voltages and amperages and, once again, it is necessary to take considerable safety precautions to protect the operators. According to the above, there is a need in this technique for a novel method for blackening surgical needles and surgical rims of metal alloy without the use of chemical or electrochemical methods.

JJ "*! DESCRIPTION OF THE INVENTIONAccording to the above, it is an object of the present invention to provide a method for blackening the surfaces of surgical needles and metal alloy surgical instruments without the use of chemical baths. It is still a further object of the present invention to provide a method for blackening the surfaces of surgical needles and surgical instruments without the use of an electrochemical bath. It is still a further object of the present invention to provide a method for blackening a surgical needle or metal alloy surgical instrument without the need to pass electrical current through the needle or instrument. Therefore, a procedure to blacken a surgical needle or metal alloy surgical instrument is prescribed. The surgical instrument or surgical needle has an outer surface and, optionally, an inner surface. Surfaces The surgical needle or metal surgical instrument is exposed to a gaseous plasma for a sufficient time at a temperature sufficient to effectively blacken the surfaces of the needle or instrument. The novel method of blackening surgical needles or surgical instruments of the metal alloy of the present invention has many advantages. The environmental risks associated with the use of chemical baths and electrochemical baths are eliminated since these chemical baths are not needed. Adernae, gaseous plasma that is used to blacken the surfaces of surgical instruments and surgical needles can be recovered and recirculated after each procedure. Yet another advantage of the present invention is that the need to pass an electric current through the needles and the concomitant safety risks is eliminated. The foregoing and other features and advantages of the present invention will become apparent from the following description and the accompanying drawings.

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

BEST MODALITY TO CARRY OUT THE INVENTION Gases that can be used for the plasmas of the present invention include oxygen, helium, carbon tetrafluoro, nitrogen, argon and the like, and mixtures thereof and equivalents thereof. It is preferred to use mixtures of gases such as oxygen, helium and carbon tetrafluoride. It is particularly preferred to use oxygen or a mixture of oxygen and carbon tetrafluoride or a mixture of oxygen and helium. When a mixture of oxygen, helium, and carbon tetrafluoride is used, sufficient quantities are used to "Je ca" the component to provide an effective plasma mixture. Most preferably, from about 50% to about 99% oxygen is used in such a mixture, very typically from about 60% to about 99%, and preferably from about 70% to about 99%. The "characteristic" grades of helium which are used in such a mixture are typically from 1% to about 50%, typically from about 10% to about 40% and preferably from about 10% to about 30%. %. The amounts of carbon tetra fluoride used in a preferred mixture will characteristically be from about 1% to about 40%, very typically from about 15% to about 35% and preferably from about 10% to about 30%. As previously mentioned, it is particularly preferred to use oxygen to form the plasma or a mixture of oxygen and helium or a mixture of oxygen and carbon tetrachloride. When the mixture of oxygen and helium is used, about 50% to about 80% oxygen, preferably about 80%, is used, and about 10% to about 50% helium is used, preferably about twenty%. When using the mixture of oxygen and tetrachloride «Je carbonabout 50% of approximately "80% oxygen" is preferably used, preferably about 80%, and about 10% to about 10% to about 50% of carbon tetrachloride is used, preferably about twenty%. The percentages used herein are percentages by weight. A conventional unit is typically used for the plasma treatment process in the methods of the present invention. The unit «Je plasma will characteristically have a volumetric chamber that is able to withstand both pressure and vacuum. Mounted in the camera be at least one electrode. A preferred unit "Ja is a Gasomcs plasma unit" manufactured by Gasonice / IPL, San Jose, California, however, any conventional unit or gas plasma equivalent may be used as any primary or secondary discharge unit. it can characteristically carry a gas or gas mixture to a plasma state in these units by means of exposing the gas to sufficient electromagnetic energy such as radio frequency electromagnetic waves, icroondas, etc., to effectively induce a plasma state. they can use other means to excite the gas by bringing it to a plasma state including direct current, laser energy, equivalents thereof, and the like. "If desired," the needles and surgical instruments can be exposed to a conventional plasma torch. Sufficient electromagnetic energy is applied to the gas to efficiently produce a plasma condition. Erratically, the amount of energy used is about "250U (0.12 watts / M2) to about 2500I (1.2 watts / M2), typically about 300U (.014 watts / M) to about 1000U (0.46 watts). / M), and preferably "Je approximately 400U (0.18 watts / M2) to approximate" approximately 900U (0.42 watts / M2). Of course those skilled in the art will appreciate that the amount of energy used will vary in accordance with the parameters of the process including gas flow, type of gas, electrode area, and vacuum, etc., as well as the type, size, condition and configuration of the plasma unit. The gas flows to the unit for plasma treatment procedure at sufficient volumetric flow rate to efficiently produce a plasma. The chamber volume of the unit will be sufficient to effectively contain the needles and instruments that undergo treatment. These parameters vary according to the particular parameters of the method and are easily determined by those skilled in the art. A characteristic flowchart for a blackening process of the present invention is illustrated in FIG. 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 introduce the needles or surgical instruments 10 into the chamber 25 to a unit 20 for plasma treatment. Next, a sufficient vacuum 30 is removed from the chamber 25 to effectively evacuate the chamber from air and produce a vacuum sufficient to introduce the plasma. Characteristically, the vacuum may be from about 0.05 to about 1 Torr, typically from about 0.25 to about 0.75 Torr and preferably from about 0.3 to 0.5 Torr, however this will vary with the time and configuration of the plasma unit used. Then, the chamber 25 is filled with a gas or gas mixture 40 of choice of method which finds sufficient space in the chamber 25 to efficiently form the gas plasma 50. Characteristically the gas flow used may be from about 50 to about 500 cm3 / nm, very typically from 100 to approximately 500 cm3 / mm, and preferably from approximately 200 to approximately 500 cc / nmHowever, this flow can vary depending on the type and configuration of the plasma unit used. The driving force is then switched on to activate the energy source 60 thereby forming a plasma 50, and the needles or surgical instruments are exposed to the gas plasma 50 for a sufficient time to efficiently produce an effectively blackened and non-reflective coating on the Surfaces of needles and surgical instruments 10. Characteristically the plasma cycle time can be from about 10 to about 120 minutes, very characteristically from about 20 to about 40 minutes, and preferably from about 30 to about 45 minutes, however , this will vary depending on the cycle of the procedure, the parameters of the procedure, and the type and configuration of the plasma unit used. Next, the gas 40 is removed from the chamber 25 through the outlet orifice 80 and the chamber 25 is refilled with an inert gas 70, such as nitrogen, and maintained at sufficient pressure for a sufficient amount of time. to effectively cool the needles or instruments. For example, needles or instruments may be maintained in the cooling phase for about 3 to about 10 minutes, typically about 3 to about 7 minutes, and preferably about 3 to about 5 minutes. The pressure of the inert gas can be, for example, from about 0.05 Torr to about 1.0 Torr. Finally, the blackened needles and instruments 100 are withdrawn from the chamber 25 of the "je" gas unit 20. The gas 40 withdrawn through the exit hole 80 can be recirculated for use in the process. The oxide layers produced by the blackening process by plasma treatment The present invention is sufficient to effectively provide a conventional blue / black non-reflective coating to the surfaces of the needles or instruments 10. The outer surfaces are characteristically blacked out. The needles or instruments 10, however, can be used to blacken the interior surfaces. Surgical needles that can be blackened using the method of the present invention include any conventional surgical needle having a piercing, sharp or obtuse tip, and a suture mounting end. The end of the suture assembly may have a channel or a perforated hole to receive the sutures. Surgical instruments which may be blackened by the procedure of the present invention include conventional instruments and parts thereof such as needle holders, scissors, forceps, scalpels, catheters, cutting instruments, clamps, 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 may have interior surfaces as well as exterior surfaces. The oxide layers produced by the plasma treatment blackening process The present invention will be sufficiently thick to efficiently produce a blue / black to black non-reflective coating on the metallic surface. The following example is illustrative of the principles and practice of the present invention.

EXAMPLE Approximately 1,000 surgical needles made of the 455 metal alloy were placed in the chamber of a Gasomcs plasma unit < R > . The chamber had a volume of approximately 113.27 dm3. The unit door was sealed and the chamber evacuated to a vacuum of approximately 0.15 Torr for approximately 1 minute to purge volatile and contaminating substances. The chamber was immediately refilled with a mixture of 50 cm3 / minute of oxygen and 50 cm3 / minute of helium at a pressure of about 0.3 to about 0.5 Torr. The gaseous mixture was maintained in the chamber before the power was switched on for approximately 2 minutes. Next, the energy was connected to the unit and the needles were exposed to the resulting gaseous plasma which was maintained at an energy level of approximately 1,000 watts for approximately 90 minutes. Then, the energy was disconnected and the gaseous mixture "Je la cama" was evacuated. Next, the chamber was filled with nitrogen and maintained at a pressure of about 1.0 Torr for about 3-5 minutes until the needles were cool enough to be handled. The needles were then removed from the chamber of the gas plasma unit. After an inspection, it was observed that the surface of the needles had a conventional non-reflective black blue to black appearance. The method of the present invention for blackening surfaces of surgical needles or metal alloy surgical instruments has many advantages. Surprisingly and unexpectedly, it is now possible to blacken the surfaces of surgical needles and metal alloy surgical instruments in a controlled procedure that does not use chemical or electrochemical baths and that does not generate the associated hazardous waste, emissions and currents of waste. At Jemas, the use of high amperage electric currents is eliminated in order to electrically black the needles. Yet another advantage of the present invention is that the needles which are treated in the plasma process of "gas of the present invention are not subjected to metal removal which is a characteristic disadvantage of chemical or electrochemical processes. Still another advantage of the process of the present invention is that it is significantly cheaper and less expensive than conventional blackening methods according to the prior art. The method of the present invention also eliminates the safety deficiencies associated with conventional blackening procedures. Even though this invention has been described and described with respect to the "Jetalladae" modalities, experts in the art will understand that it is possible to make several changes in form and detail thereof without "Jesviaree". "Jel spirit and scope of the claimed invention.

Claims (16)

NOVELTY OF THE INVENTION CLAIMS

1. A method for blackening the surface of a metallic surgical needle, comprising the method of: exposing a metallic surgical needle having an exterior surface to a gaseous plasma for a sufficient time at a temperature sufficient to effectively produce a layer of a metal oxide. enough to produce a blackened color to the outer surface.

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 of claim 1, further characterized in that the gaseous plasma consists of a mixture of oxygen, argon and carbon dioxide.

4. The method of claim 1, further characterized in that the plasma mixture comprises from about 50% by weight to about 99% by weight of oxygen and approximates from 1% by weight to about 50% by weight of helium and about 1% by weight to about 40% in phosphate "Je tetrafioride" He carbon.

5. The method of claim 1, further characterized in that the metallic needle consists of an alloy selected from the group consisting "Je stainless steel T-420, stainless steel TF, stainless steel T-455 and stainless steel alloy rnartensitic titanium-nickel.

6. The method of claim 1, further characterized in that the gas plasma is excited in an energy source, because the energy source consists of a selected member between the group consisting of radiofrequency, microprobe and discharge of energy. direct current.

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

8. The method of claim 1, further characterized in that the "gaseous" plasma consists of a mixture of oxygen and carbon tetra fluoride.

9. A method for blackening the surface of a metal surgical instrument, by attaching the principle of exposing the metal surgical instrument having an outer surface to a gaseous plasma for a sufficient time at a temperature sufficient to effectively blacken the outer surface of the needle.

10. The method of claim 9, characterized by the fact that the gaseous plaema consists of a mixture of oxygen and helium and carbon tetrachloride.

11. The method of claim 9, further characterized in that the gaseous plasma consists of a mixture of oxygen and argon and carbon tetrafioride.

12. The method of claim 9, 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% of carbon tetrachloride,

13. The method according to claim 9, further characterized in that the metallic needle consists of an alloy selected from the group consisting "Je stainless steel T-420, steel stainless steel TF, stainless steel T-455 and stainless steel alloy nartensitic titanium-nickel.

14. The method of claim 9, further characterized in that the gaseous plasma is excited by an energy source, because the source consists of a member selected from the group consisting of radiofrequency, icroonde and "direct current charge". .

15. The method of claim 9, further characterized in that the plasma consists of oxygen.

16. The method of claim 9, further characterized in that the instrument further comprises at least one interior surface, and also the interior surface is blackened. 1.7.- The method of claim 1, further characterized in that the needle is in addition to at least one inner surface, and also the inner surface is blackened. 18. The method of claim 9, characterized in that the gaseous plasma consists of a mixture of oxygen and tetrachloride. 19. The method according to claim 9, further characterized in that the "gaseous" plasma consists of a mixture of oxygen and helium. 20. The method of claim 1, characterized admirable because the gaeoeo plaema coneta a mixture "Je oxygen and helium.