US1377725A - pentz - Google Patents

Description

' J. B. PENTZ.

METHOD 0E STERILIZING SURGICAL INSTRUMENTS AND OTHER ARTICLES.

l* APPLICATION FILED MAR. 4,19l5. 3193779725 Patentd May MP9 19231.

` v *t 2 SHEETS-SHEET I.

am: n

[Hummm] i III-IiiiiIIIiiiiiii IIIIIIII Il IlIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII||||IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII le; IIIIIIIII-IIIII gag! ii 'IIIIIIII II R I. B. PENTZ.

METHOD 0F STERILIZING SURGICAL INSTRUMENTS AND OTHER ARTICLES.

APPLICATION FILED MARMI, ISII5.

Iimf, Patented May III, 1921.

2 SHEETS-SHEET 2.

JAMES BOLTON PENTZ, OF NEW YORK, N. Y.

METHOD'OF STERILIZING SURGICAL INSTRUMENTS AND OTHER ARTICLES.

Specication of Letters Patent.4

Patented May 1U?, 1921i..

Application led March 4, 1915. Serial No. 11,951.

To all w from if may oon-cern Be it known that I, JAMES BOLTON PENTZ, a citizen of the United States, residing at New York, county of Richmond, and State of N ew York, have invented certain new and useful Improvements in Methods of Sterilizing Surgical Instruments and other Articles, of which the following is a full,

. clear, and exact description.

Experience with, and careful study of, practically all known methods of sterilization for a considerable period have led me to the conclusion, shared by many other surgeons and bacteriologists, that there is great need of a method which shall be unfailingly perfect in its results but which will at the same time be quick and convenient to use. To this end I have devised my present invention, which has for its chief object to provide a method which shall be practically instantaneous in its effects and yet render the instrument or appliance sterile in the true sense of the word. A further object is to provide a method which can be practised by means of simple and durable apparatus of low cost. To these and other ends the invention consists in the novel method and features hereinafter described.

In practising my invention in the preferred manner the instruments or other articles to be sterilized are subjected, in the presence of vapor, to a temperature high above the boiling point of the liquid from which the vapor is produced, the heating of the article being effected in a vessel or container which is not hermetically sealed but is open to the atmosphere for the escape of theI steam, or vapor, as the case may be, so that the pressure within the container or chamber will bel but little, if any, above atmospheric. Heretofore, subjecting the instrument, in the presence of steam, to a temperature above the boiling point of water at` atmospheric pressure has always implied the use of a. closed receptacle and a pressure therein corresponding to the temperature. It is well known that, however effectual such a procedure may be, it is slow, at times requiring hours for the attainment of perfect results. Why this is so I am not able to explain with certainty, but the fact remains. On the contrary, in the use of my method the time of complete sterilization is counted by seconds instead of minutes or hours, and in fact the time ishusually so short-five or six seconds or even less, depending generally upon the temperature employed`that the method for all practical purposes can be called instantaneous.

he apparatus which I prefer to use for performing the process is illustrated in the accompanying drawing, in which- 'Figure 1 shows the complete device in longitudinal vertical section.

Fig. 2 is a cross section on line 2 2 of Fig. 1.

F 3 is a detail side view of the inner heating element, the outer protective casing being in section.

Fig. is a side view, partly in longitudinal section, of a modification of the sterilizer shown in Fig. 1.

Fig. 5 is a side view, of a` liquid reservoir sterilizer.

The outer casing is preferably cylindrical in form and mounted in a slightly inclined position on a support-ing base 11. The inner heating element is in the form of a chamber 12 preferably elliptical in cross section, provided at one end with a head 13 and near the other with a radial flange or collar 14 to support the chamber cenrally in the casing 10 and spaced from the walls thereof. Removable caps 15, 16, of conical form, are provided for the ends of the casing and are fastened against accidental displacement by means of binding bolts 17, 18. Each cap is formed with a central aperture, that in cap 15 being provided for the electrical connections hereafter described and that in cap 1.6 to permit insertion and withdrawal of the drawer or cage 19.

In the present apparatus the heat is produced preferably by the iow of current through a resistance wire wound around the chamber 12, but insulated therefrom by means of insulating strips 21, of porcelain or other suitable material arranged longitudinally on the chamber and held in place by wires or bands 22, the insulating strips or bars being serrated, as shown, to receive the wire 20 and insure proper spacing of its turns. Notches 12a in the strips 21 next to the chamber 12 permit surplus water, discharged oii the top of the chamber as hereafter described. to run freely down the sides of the chamber. The terminals of the heating element pass through insulating tubes or bushings 23, 24, into electrical conpartly broken away, for use with either head 13. Connection with a source of current is made by means of a socket 26. Preferably the socket is overlapped by the edge cap 15, as shown in Fig. 1, to prevent accidental unscrewing of the socket as the plug (not shown) at the other end of the cord 27 is screwed into its socket. Removing the cap 15 will of course permit removal of the socket 2G.

On the casing 10 is a reservoir 23 for the liquid u sed (by preference ordinary water) having a sight feed 29' through which the water is delivered onto the heating element. A needle valve 30, threaded in a tubular support 31, controls the flow of water so that the delivery may be drop-by-drop at any desired rate. The lid 32 is merely dropped on the reservoir, and may be removed instantly for cleaning or filling the reservoir. In the bottom and sides of the chamber I provide a number of apertures 33 to permit free ingress of steam into the chamber.

The tray or drawer 19 is foraminous, preferably throughout its entire length, though for convenience the perforations or apertures are shown only at the ends. It is usually semi-elliptical in cross section, but enough smaller than the chamber 12 to leave a space between the two, at least at the bottom, as clearly shown in Figs. 1 and 2, to permit free access of the steam. On the outer end of the tray or drawer is a cap 34 of the aperture in the having a flange 35 engaging at severalpoints the projecting end of the chamber 12 and thereby aiding in supporting the tray inside the latter. It is not intended, nor is it even desirable, in the absence of a steam escape opening elsewhere, that the cap make a close fit with the chamber-end, and in fact the chief object of providing the cap and flange is to deflect escaping steam radially outward and so protect the hand more effectually when the handle 36 is grasped to insert or remove the drawer. The escape of steam around the cap 34 or through an escape opening elsewhere, insures a pressure in the sterilizer but little, if any, above atmospheric during sterilization.

In practising my method in the preferred manner with the apparatus described, the current is turned on and the reservoir supplied with water. In a few minutes, depending on the strength of the current, the size and nature of wire 20, etc., the chamber 12 becomes highly heated, inside and out, say to a temperature of from 200O to 300O C. The valve 30 is now opened and the water thus allowed to issue, preferably drop by drop. The heat generated by the heating element vaporizes the water, and the steam thus produced passes into the interior of the sterilizing chamber 12 through the openings 33 in the walls thereof. The

tray 19 with the non-sterile instruments or other articles lying loose therein, is now inserted into the chamber 12 (if not already in the chamber), thus exposing the contents of the tray to the heat radiated from the hot walls of the chamber and to heat carried to said contents by the steam. How long the instruments should be left in the tray depends largely upon the temperature in side the sterilizer. For example, instruments bearing large quantities of typhoid bacilli were rendered completely sterile in six seconds, when the temperature was about 2930 C., in ten seconds at 275o C., and in fifteen seconds at 2350-2500 C. I amnot aware that results comparable to these have ever been attained with any practical h eatprocess of sterilization heretofore known.

Upon removing the tray, moisture in the form of a film or in drops is usually found on the instruments, but the latter speedily dry of their own heat. Moreover, they usually cool quicklyy to a safe handling temperature for the reason that seldom if ever do they attain, except possibly at their surfaces, the temperature to which they were subjected in the sterilizing chamber. This is shown by the fact that with the sterilizer running at its maximum temperature a thermometer placed therein required 26 seconds to reach 150o 200O C., 1 minute and 3 seconds to reach 250O C., 1 minute and 25 seconds to reach 275o C., and 2 minutes and 23 seconds to reach 300O C. It is not necessary to insert' the tray far enough to close the sterilizing chamber, but if the tray is no llonger than necessary to accommodate the instruments the latter may project out of the chamber if the tray is not pushed home; in which case the parts that project say an inch or more may not be completely sterilized, though the parts well inside the chamber will be made perfectly sterile.

I am not able to explain to my complete satisfaction just why the method described is so effective, since it contravenes the previously accepted theories that would apply. But the fact remains that the process is demonstrably superior in cihciency and convenience to boiling or baking, and to the use of steam under high pressure and at a corresponding temperature. f

Water and steam are referred to herein as the most convenient for the purpose, and in fact I know of none better, but other liquids may be used; and it is within the spirit of my invention to use an aqueous solution of a volatilizable germicide, but I have not observed that any better results are obtained thereby. I also prefer to generate the steam or other vapor by discharging a liquid upon or into the heated sterilizing chamber, or at least into the outer casing, but the generation can be effected at a more C., 40 seconds to reach remote point and the vapor conveyed to the sterilizing chamber through suitable pipes.

The sterilizer shown in Fig. 4 dilfers from that shown in Fig. 1 practically only in respect to the heating element. The latter, in Fig. 4, comprises a sheet metal tube or chamber covered with a layer of refractory insulating material, preferably mica or mica-composition, on which the resistance wire 4l is mounted, as by winding the same helically thereon. The heat thus generated heats the tube 40 and the water or other liquid is delivered to the-inside of the same through the short tube 42 at the top from any suitable reservoir, for example one like that shown in Fig. l or that shown in Fig. 5. In the latter, which is formed at the bot-- tom to screw on the nipple 43, the needle valve is omitted and the central tube 44 is imperforate at the bottom and open at the top. Slidable vertically on this tube is a cup 45 attached to the bottom of a tubular stem 46 capable of vertical movement on said central tube and having drain apertures 47 at the bottom. A spring 48, encircling the tube 44 holds the cup and stem yieldingly in their upper position, against the flared upper end of the aforesaid tube. water is to be delivered to the sterilizer the stem is pressed down, carrying the cup down into the reservoir 49, causing the cup to receive water therefrom. Upon re- .lease of the stem the cup is raised to the position shown in Fiof. 5, carrying with it a quantity of liquid, w ich runs out through the drain openings 47 into the tube 44 and thence through the nozzle 50 into the sterilizer. This method of liquid-supply eliminates trouble due to leaky valves and consequent iooding of the sterilizer, since only a limited quant-ity of liquid is delivered at 1 each actuation of the measuring cup. A

drain tube 51, Fig. 4, permits immediate escape of any excess liquid from the sterilizer.

It is not necesary that the articles to be sterilized be heated before they are placed in the sterilizer. It is more convenient and is apparently quite as effective to introduce them at whatever temperature they may happen to have, which is usually ordlnary room 4 temperature.

It is to be understood that the invention is not limited to the apparatus herein specifically illustrated, but can be practised by means of other devices of Widely varying character.

ll claim:

l. The herein described method-of sterilizing which consists in subjecting the article to be sterilized to a temperature above the When boiling point of water, in the presence of steam at substantially amospheric pressure. 2. The herein described method of sterillzing, which consists of `heating to a temperature exceeding the boiling point of water, a chamber containing the article to be sterilized, and introducing steam at substantially atmospheric pressure into the chamber and into contact with the article.

3. The herein described method lof Sterilizing, which consists in inclosing the article to be sterilized in a chamber having a temperature high above the boiling point of water and containing steam at substantially atmospheric pressure.

4. The herein described method of sterilizing, which consists in subjecting the article to be sterilized to an atmosphere containing steam at a temperature exceeding the boiling point of water and at substantlally atmospherc pressure.

5. The herein described method Vof sterilizing, which consists in preparing an atmosphere having a temperature 'exceeding that of boiling water, supplying steam at substantially atmospheric pressure to said atmosphere whereby the temperature of the steam is increased, and introducing the article to be sterilized into said atmosphere in a relatively cold state.

6. The herein described method of sterilizing, which consists in subjecting the article to be sterilized, in a relatively cold state, to steam at a temperature above the boiling point of water and at substantially atmospheric pressure.

7 The herein described method of sterilizing, which consists in subjecting the article to be sterilized to heat radiated from the walls of a chamber heated to a temperature exceeding the boiling point of water and to steam at substantially atmospheric pressure.

8. The 4herein described method of sterilizing, which consists in subjecting the article vto high temperature radiated heat and at the same time to steam at substantially atmospheric pressure.

9. 'llhe herein described method of sterilizing, which consists in inclosing the article to be sterilized in a chamber having walls heated to a temperature high above the boiling point of water, whereby the article is heated by radiation, and containing Isteam at substanitally atmospheric pressure.

In testimony whereof l aHiX my signature in the presence of two subscribing witnesses.

JAMES BOLTON PENTZ.

Witnesses:

N. LAWSON Dime, S. S. DURHAM.

Images