JPS60256458A - Disposable test pack for vacuum type steam sterilization apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to the sterilization of medical and surgical supplies, and more particularly to checking whether a pre-vacuum steam sterilizer is operating properly. The present invention relates to disposable test packs that are intended to be processed through a conventional sterilization cycle in this sterilizer for the purpose of the present invention.

BACKGROUND OF THE INVENTION In the sterilization of medical clothing and equipment, such clothing or equipment is generally bundled or packed and placed in a steam sterilization chamber in sequence during a suitable sterilization cycle. Individual packs may include towels, clothing, sponges, and similar mass of materials, and may also include the necessary components of surgical instruments and equipment for a particular surgical procedure.

The conventional method for carrying out steam sterilization involves placing a pack such as the one described above inside the sterilizer, venting the air from the sterilizer, and removing the air for a selected period of time to create the required temperature. It consists of introducing saturated steam at pressure. This situation is often replaced by a transposition or gravity air exhaust sterilizer. An important advantage of the pre-vacuum method is that
Removal of the air prior to introduction of the steam results in rapid penetration of the steam throughout the surgical pack.

Air removal is necessary in all steam sterilizers because air within the pack prevents sterilization of the portion of the pack in which it is concentrated. According to the pre-vacuum method, the time required for steam penetration in a typical sterilization cycle is significantly reduced, and pre-vacuum sterilizers are generally operated in relatively short cycles. ℃
Expose for about 3 to q minutes. Such sterilization equipment is operated by Charles C. Thomas of Springfield, Illinois (CharmeSC).

Pr1ncip1θ5 and Methods of John J. Perkins, published by Thomas
5terilization, in the He
althSciences Chapter 6 “Prevacuum
m HlghTemperature 5terili
It is well stated in zation j.

However, the ability to sterilize instruments within a shortened period of time is
This is based on the assumption that air is properly vented from the sterilizer. This includes the expectation that the vacuum equipment will function properly to first evacuate the sterilization chamber, that there will be no air leaks in the vacuum lines or sterilization equipment that will allow the introduction of air after the vacuum has been evacuated. There is. Through daily use, parts of worn-out sterilizers will eventually develop air leaks, and sterilizers should be tested on a regular (daily) basis to ensure that the vacuum system is functioning properly. There is a need to.

In 1911, this test method was developed by G. Dick (: r
, r+1ch) et al., and Jie et al., Department of Microbiology, Royal Infirmary, Nibbinburgh, Scotland.
The Lancet, March lt, 7963, by J. H. Bowie et al.

This article is described in the article on page sgt-rg, which provides suggestions for checking whether the sterilizer is in proper working order and whether the vacuum system is working properly. As shown in this article, any air remaining in the device at the time the steam is directed is forced by the pressure of the steam into the bag, generally into the center of the pack. Air within the pack inhibits proper vapor penetration.

According to the original proposal by Horei and Dick, sterilization indicator tape was used along with a bundle of surgical towels to test the operating condition of the sterilizer on a daily basis. The sterilization indicator tape is an adhesive tape having stripes of sterilization indicator material printed on its top surface which have the property of changing color, for example from white to black, when exposed to steam for a suitable period of time and at a suitable temperature. According to Borei and Dick's original plan, the tape was placed in a cross pattern on a woven sheet, and the woven sheet was placed inside a bundle of folded surgical towels. The entire assembly was placed into a sterilizer. The sterilizer is 13
3～～／、? The tape was run through a normal cycle of steaming for 3.3 minutes at 'l'C, after which the tape was inspected to see if the steam had effectively and completely penetrated the towel bundle. A constant discoloration indicates the passage of steam, and an incompletely changed indicator color indicates a defect in the device.

This draft has been widely used and published by the Association for the Advancement of Medical Instrumentation (AAMI).
ation For The Abvancemen
Of Mechanical■nstrumentat
ion Recommended Practice
: GoodHoL3pital Practice
fOrSteam 5tGri], 1zatiOnan
d 5terility As5vrance J.

"Prevacuum 5terilizer Re5
No. 7 of the publication entitled dual Air Te5t J. As indicated in paragraph 1, this test is carried out using 2 mm x 3 mm, which has been washed clean and not coated with iron, as excessive drying will affect the test results. g mm (9 inches x l
9. We use 700% cotton hackback towels stacked to a height of lI millimeters (10 to 11 inches). For details of Boley and Dick's method, see "A" in the above reference.
AM Engineering Recommended Practice J
Ic<G:,h? r;E+. 1.j Problems to be Solved by the Invention The testing of pre-vacuum sterilizers according to the Borley and Dick proposal has several serious drawbacks. Firstly, this test was carried out in accordance with the individual implementation by hospital sterilization departments on a daily basis, and the various needs in the Boley and Dick original, i.e. the types of towels and other fabrics used, their Conditions, longevity, etc. (all of which affect the significance of the test results) vary widely from day to day and hospital to hospital.

Second, the implementation of Boley and Dick's proposal is relatively inconvenient, with hospitals having to pay for the cost of washing the towels (which must then be washed again before they can be used) and assembling them into the test configuration. It is uneconomical as you have to pay for it. In addition, some hospitals have completely eliminated laundry facilities by using single-use, disposable fabrics for their implementation, which again reflects the proper implementation of Boley and Dick's original proposal. It's an inconvenience.

OBJECTS OF THE INVENTION It is an object of the invention to provide a test pack for use in a pre-vacuum steam sterilizer to determine whether the device is functioning according to appropriate standards. It is also an object of the present invention to improve the conventional bag air venting and steam infiltration conditions described in the Boley and Dick draft to determine appropriate conditions for residual air testing in pre-vacuum sterilizers. The aim is to provide a test pack that mimics the

It is also an object of the present invention to create a test bank for pre-vacuum sterilizers that provides a repeatable and constant basis for testing the operating condition of the sterilizer from day to day and from sterilizer to sterilizer. be. Furthermore, it is an object of the present invention to provide a test bank that is inexpensive, can be discarded after seven uses, does not require assembly by hospital personnel, and does not require the use of hospital linen products or laundry equipment. It is in.

DESCRIPTION OF THE INVENTION In achieving these and other objects in accordance with this invention, a sterilization test sheet having a limited portion adapted to change color in response to the presence of steam under selected conditions of exposure to steam. The sheet is surrounded by seven sets of disposable porous nonwoven sheet materials arranged in overlapping relationship above and below the sheet. The deepest sheet material forms the inner core around the test sheet, the remaining sheet material forms the outer skin, and the porosity and size of the inner core and the porosity of the outer skin are sterile. chosen to define the required conditions for the device.

The test packs were used in accordance with the generally accepted protocol of Horley and Dick, and were placed in an empty sterile chamber, run sequentially through a predetermined cycle, and removed. . The pack is then opened and the test sheet inside is inspected for evidence of insufficient steam penetration, air bubbles, and similar defects.

The presence of such defects indicates a malfunction in the vacuum system or other equipment of the sterilizer that requires inspection or repair. This test is intended to be performed daily with an internal test notebook forming a permanent representation of such test. The non-woven sheet material and other parts of the ivy are discarded after seven uses.

Other objects, features and advantages of the invention will become more apparent from the following detailed description of preferred embodiments according to the invention, taken in conjunction with the accompanying drawings.

EXAMPLE The test pack 10 of this application has a sterility test sheath of the known type. The test sheet 12 is generally a rectangular, relatively porous sheet onto which vapor-sensing ink is applied in a test pattern designed to cover the entire surface of the test sheet 12. It's paper.

Suitable test sheets for this purpose are the Once A. This test sheet is shown in U.S. Pat. No. D-2,22, 16.

The ink portion of this test sheet 1- changes color from white to black when exposed to steam for a required time and at a required temperature. Insufficient exposure to steam will only partially cause the ink to change color from white to black.
The color changes from white to black over a certain period of time. This partial discoloration can be seen on the test sheet l- as white, brown or light colored areas. This type of test sheet 1.2 is commonly known to those skilled in the art and has been used in place of the cross-shaped sterile tape strip shown in the original Boley and Dick test procedure.

The new test pack 10 of this application does not use the traditional bundle of cotton towels according to the original idea of Boley and Dick.
It is designed to use a test sheet lλ such as the Once a Day test sheet. As indicated in the Boley and Dick original description, various types of defects are very frequently found in sterilization equipment. The main deficiencies are (1) insufficient initial vacuuming, i.e., air remaining in the pack 10, and (2) sterilization rooms where air flows in again after being evacuated. This is an air leak from the vacuum device. In designing a test pack to test for these two defects, and other similar defects,
It has been found that there are various constraints in driving.

For example, large volume test packs with low porosity are more likely to exhibit such defects than small volume test packs with high porosity, to the extent that defects exist in the vacuum apparatus where sufficient vacuum is not created in the first place. . When emptied, the air within the test pack tends to be drawn out of the pack. Large materials with low porosity surrounding the test sheet tend to increase the difficulty of air removal and the likelihood that the test pack will exhibit defects.

On the other hand, defects caused by leaks consist of air entering the sterilizer after being evacuated. In this case, the relationship between the porosity of the material surrounding the test sheet and the sensitivity of the test is diametrically opposed. The fewer the pores in the material surrounding the test sheet and the larger their size, the greater the tendency for air introduced into the sterilizer after being evacuated (in case of a leak) to re-enter the test bag. Therefore, with respect to defects resulting from air leaks after being fully evacuated, the less porous material surrounding the test sheet will make it difficult for air to enter the test bag from such leaks, resulting in such test punctures. tends to reduce the likelihood that the

In order to properly test sterilization devices, test bags must reconcile these conflicting needs and provide appropriate conditions for common types of defects. A suitable test bag for this purpose is a folded cotton hackback towel according to the original idea by Boley and Dick! ! ,
A conventional method based on 4Z to near, 9 cm bundles is a generally accepted standard. It would be desirable to design a test bag that is compact, inexpensive, and disposable.

By placing a unique sheet of disposable material above and below a suitable test sheet/'2 and wrapping it, it is possible to detect deficiencies in common sterilizers, similar to the original idea of Boley and Dick. It is possible to create a test bank lθ with Such sheet materials are assembled to form an inner core portion adjacent to the test sheet 1:2 and outer skin portions above and below this inner core portion, and the thickness and porosity of the inner core portion and the porosity of the outer skin portion are determined. and are selected according to the required parameters.

A preferred construction of the test bag 10 of the present invention, shown in FIG. There is.

In a preferred embodiment, the nonwoven sheet material has an inner core portion/'
4 and the second type forming the outer skin part lO, 1□, 4iZ6. i□ The entire package is wrapped with wrapping material/1 of appropriate porosity and tape, 20, to form a seal. In a preferred embodiment, the porosity of 1 g of packaging material will be such that it does not affect the test.
6 has a velocity of 27 g, g square meter (3θθO 96.9 kilograms per square inch (, 21 < 2 bond), i.e. 34 g grams per square meter, and the thickness of the l sheet is 0.37 mm (O, O). :1 Indeno filter paper is made of Yu-ha.This 7-t material 1r
Each sheet has a Frazier porosity of about O.S to S cubic feet per square foot minutes.

This Frazier porosity is a Frazier porosity manufactured by Frazier Precision Instrument Company, Inc., 210 Oakmont Apenu, Geysers Park, Maryland.
DifferentialPressure Afr.
Permeab soil 1 soil ty Measuring M
Quantification of air permeability of sheet material as measured by achine. This porosity measurement (c) is based on the principle of subtractive pressure, such as the measurement by a manometer.
The amount of air (given in cubic feet) that passes through 9 square centimeters (l square feet) per minute at a pressure of , 5 inches of water).

Another common method of measuring the porosity of sheet materials is the Gurley test method, which consists of measuring the time required for Iθθ milliliters of air to pass through an l square inch area of specimen material under constant pressure. . Of course, the Frazier porosity given in cubic feet per square foot minute can be expressed in terms of other metrics.

The inner core section /41 in the preferred embodiment of FIG.
．． At a rate of 0 kilograms (6 dowels), i.e., top, o grams per square meter, approximately 0. ! /mm (O,O2 in nano) filter paper. The sheet material has a Frazier porosity of 75 to 93 cubic feet per square foot minute.

In a preferred embodiment, the height of the internal window section /4 is 39 mm (0, g) above and below the test sheet /2, respectively.
2a inch) and the total porosity of the sheet material of the internal window portion ltt on each side of the test sheet/2 is approximately 4.9 to
, q cubic feet ga square feet. In a preferred embodiment, the outer skin section 16 has 2. It has a thickness of 0.0 mm (0,000 mm) and a Frazier porosity of about 0.1 to 0.3 cubic feet per square foot minute on each side of the interior window section /li.

Test bag to, sheet material and test sheet t 2td
The Frazier porosity of the bundle of sheet material used in the Ukohe is preferably mm, but other dimensions can be used with possible variations in other parameters: 22g,t, mm x 3oa,g , each sheet of material has a porosity of 90 cubic feet per square foot.
The bundle of sheets is sawed so that each sheet has a porosity of 70/1, or 9 cubic feet per square foot.

By forming the outer skin portion 16 to be of relatively low porosity compared to the inner window portion llI, the number of sheets of material and the height of the test bag 10 are reduced, with concomitant savings in material and cost. significantly reduced. The interior window portion of the test bag IO on each side of the test bag IO/& east of the sheet material preferably has an overall Frazier porosity of not less than t, S cubic feet per square foot minute, and ,
Its thickness is at least Q, 7 A 2 mm (o
, o, y intin is desirable.

In addition, the Frazier porosity of the outer skin part L is ゛ ′O0
It is desirable that it be under S cubic feet cubic feet square feet fractions. j・(□ As previously indicated, this disposable test bank 10 responds to sterilization device deficiencies in a manner comparable to cotton towels prepared according to the original idea of Boley and Dick. The embodiment achieves this desired objective.

Experiments were conducted in a specially designed pre-vacuum steam sterilizer that had been modified to simulate controlled and reproducible sterilizer defects. This pre-vacuum steam sterilizer has a vacuum pump that can be manually controlled to vary the degree of vacuum within the device and an adjustable volume piston-driven air injector. Incomplete air evacuation was simulated by evacuation of the sterilization chamber to 60 mm of mercury at one time and omitting subsequent evacuations. Air leaks in sterilizers can be eliminated by adjusting the stroke of the injection piston to deliver a specific amount of air into the sterilization chamber during the normal steam exposure cycle after the air has been sufficiently and completely evacuated. simulated.

Test sheet 1 in a preferred test bag 10 of this invention
2 is now visually reviewed in a general manner for the device used in the original Borrei and Dick draft. For quantitative experiments, the color change of the chemical instruction sheet was measured using a reflectometer (Model XL-20 Gardner/Neotic Instruments, Pacific Scientific, Silver Spring, Maryland) equipped with a lO mm orifice device. Division)
investigated by.

Using a green filter, the instrument measures the reflectance of the white to black color change and meets the American Society for Testing and Materials (ASTM/9
? ? ) was used according to the method prescribed by The upper limit for the percentage of reflectance is measured as the lid for the non-vapor exposed white of the sheet using a suitable commercially available once-a-day test sheet, and for the fully steam exposed black. It was S for the seat. The area of the incompletely steam exposed portion of the test sheet is determined by calculating the area of the ellipse that best describes the perimeter of the incompletely steam exposed portion.

Experiments have shown that the results of two common defects on test sheets are the same for the disposable test bag 10 of the present invention and the conventional test sheet prepared according to the Boley and Dick draft. It was done. Data was collected regarding the surface area of the undeveloped portion of the test sheet and the reflectance at the center of the indicator sheet within this undeveloped portion.

The measurement data is as shown in the following table. The measured surface area product results of the imperfections in the experiment are comparable to similar results for the conventional Borley and Dick design. This relationship is the third. This is shown in the Q diagram. Figure 3 shows the product of area and reflectance plotted against vacuum. Figure 9 shows the simulated air leakage based on the product of area and reflectance plotted against the volume of injected air (to' times the volume of the sterilization room). A similar comparison is shown for data collected by

Third. As shown in the data display in Figure '1, the area and reflectance products for the test puncture of the present invention and the conventional Borley and Dick design closely track each other.

The above is considered to be an illustration of only the essence of the invention. Moreover, since modifications and changes will readily occur to those skilled in the art, it is not desirable to limit the invention strictly to the configuration or operation illustrated; therefore, all suitable modifications and equivalents are contemplated by the claimed claims. The present invention may be practiced without departing from the scope of the invention, which may be limited in scope.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway perspective view of a test bag according to the present invention, Fig. 2 is a partial sectional view taken along the course line of Fig. 1, and Figs. 2 is a graph illustrating the relationship between the results of experiments conducted by the test bank and the results of experiments conducted according to the traditional test back of the Bohrei and Dick proposal. In the figure, 10...Test bag, /2...Test sheet, /lI...
Inner window part, 16...Outer skin part, 1g...Packaging material, 20
··tape. Engraving of the drawings - (no changes to the contents) FIG, 4゜ Procedural amendment June 26, 1980 Gakudono Shiga, Commissioner of the Patent Office1, Indication of the case 1982 Patent Application No. 1067012, Preliminary title of the invention Disposable Test Bag 3 for Vacuum Steam Sterilizers, Relationship with Amendment Case Patent Applicant Name: Protuber Manufacturing 77 Manufacturing Company, Inc. 4, Agent: 100 Address: Marunouchi, Chiyoda-ku, Tokyo 2-4-1 Marunouchi Building 4th floor drawing

Claims (1)

[Scope of Claims] l A sterilization test sheet having a limited portion adapted to change color in response to the presence of steam under preselected sterilization conditions, wherein a change in the degree of color change indicates sterilization. a first combination of disposable porous nonwoven sheet material positioned adjacent to an upper surface of said sterile test sheet and polymerized; and adjacent a lower surface of said sterile test sheet; a first combination of disposable porous nonwoven sheet materials disposed and polymerized, the first and deepest sheet materials of the first combination having a selected height and a pre-vacuum having a porosity and forming an interior window portion adjacent to the sterility test sheet and comprising a member for holding the first and first combinations in close contact with the upper and lower surfaces of the sterility test sheet; Disposable test bag for testing steam sterilizers. The internal window portion has a porosity of at least 5 cubic feet of air permeation per centimeter and a porosity of at least 5 cubic feet. A disposable test pack according to claim 1, having a height of 6 cm (0,003 inches). 3. The disposable porous nonwoven sheet material outside the interior window portion forms the outer skin portion of the disposable test pack, and the sheet material of the outer skin portion has a Frazier porosity of no more than θ, S cubic feet of air passage. A disposable test pack as claimed in claim 1. The disposable test pack of claim 1, wherein the disposable porous nonwoven sheet material comprises sheet materials having individual porosities. 5. The disposable test pack according to claim d, wherein the sheet material forming the inner window portion has a seventh porosity, and the sheet material forming the outer skin portion has a first porosity. (b) Equipped with a sterilization test sheet having a limited area that changes color in response to the presence of steam under preselected sterilization conditions, where changes in the degree of color change indicate changes in sterilization parameters; , a first combination of disposable porous sheet materials disposed adjacent to and superimposed on a top surface of said sterility test sheet; and a first combination of disposable porous sheet materials disposed adjacent to and superposed on a bottom surface of said sterility test sheet. a first set of disposable porous sheet materials, the first and deepest sheet materials of the first combination forming an inner core portion adjacent the sterilization test sheet; and an outer sheet material of a second combination forming an outer skin portion, the overall porosity of the outer skin portion being less than the overall porosity of the inner core portion, for maintaining the members as a unitary assembly. A disposable test pack for testing the pre-vacuum steam sterilizer.