WO1995024227A1

WO1995024227A1 - Isolated biological waste processor

Info

Publication number: WO1995024227A1
Application number: PCT/US1995/003027
Authority: WO
Inventors: Kathleen M. Antloga; David C. Haeberle; Raymond C. Kralovic; Kenneth R. Lamaster; David B. Mennel; Jeffrey C. Rapp; Lewis I. Schwartz; Joseph H. Wilson
Original assignee: Ecomed, Inc.; Steris Corporation
Priority date: 1994-03-11
Filing date: 1995-03-10
Publication date: 1995-09-14

Abstract

A process chamber (52, 53) for the treatment of biological waste preferably includes a rotating waste treatment sytem carried within the open-top chamber (52, 53), a cap (102) for closing the chamber opening (26), a gas-pervious liner (104) carried within the chamber (52, 53) for preventing biological waste from adhering to the cap (102) as a result of waste-treatment operations, an O-ring (156) disposed at and for sealing the interface of the cap (102) and the chamber (52, 53), and a chemically sensitive indicator (120) for indicating the presence of the chemical decontaminant.

Description

ISOLATED BIOLOGICAL WASTE PROCESSOR

Technical Field This invention relates generally to an apparatus for handling and treating biological waste materials, and more particularly, to such an apparatus including a cap liner, and a treatment indicating means.

Background Art

U.S. Pat. Nos. 5,236,135 and 5,240,187 disclose methods and apparatus for the treatment of solid and non-solid (soft) biological waste materials that permits the collection of such biological waste at the point and at the time of its generation in a container, which is subsequently transported for pulverization, decontamination and safe disposal. A separate portable processing chamber, with an integral means to treat biological waste, is used at locations remote from a main power unit for the collection of biological waste and is then moved to the location of the main power unit to drive the waste-treatment means carried within the chamber. The separate portable processing chamber includes a closable chamber, a rotatable waste treatment system carried within the chamber and a plurality of pivotable blades carried by the rotatable system which interact with the biological waste and surfaces formed on the chamber walls and provide effective disintegration and blunting of solid waste, cutting and mincing of non- solid waste, and decontamination of the biological waste within the processing chamber.

While biological waste can be effectively treated by the method and apparatus of U.S. Patent Nos. 5,236,165 and 5,240,187, treated biological waste particles can sometimes adhere and cling to the under surfaces of the cap or lid that closes the processing chamber and can drop uncontrollably from the cap or lid as, or after, it is removed from the apparatus. Although such biological waste will generally be decontaminated as a result of its treatment within the processing chamber, its escape onto adjacent surfaces requires clean-up and is undesirable. In addition, if the processing chamber is mistakenly opened before treatment and decontamination of the biological waste is completed, the escape of such biological waste can require special precautions to avoid exposure of personnel to undecontaminated biological waste.

To further safeguard the personnel handling the processing and disposal of such biological waste, it is desirable to have an indication that the decontamination agent was present in the process, or when decontamination of the biological waste has been effected.

Disclosure of the Invention The invention comprises a waste treatment apparatus including a processing chamber for the treatment and decontamination of biological waste, including such solid items as syringes and needles, glassware, tubes, vials, culture plates and specimens, and disposable scalpels, and such soft and fibrous materials as gloves, masks and bandage and gauze materials which has been provided with means for preventing biological waste from adhering to the underside surface of the cap or lid of the processing chamber as a result of operation, and, preferably, provided with means for indicating the presence of decontaminant in the cycle.

The apparatus of the invention comprises a separate waste treatment assembly including a chamber for the collection, disintegration and decontamination of soft and hard biological waste. The apparatus comprises a chamber-forming means forming an opening, with a waste treatment system rotatably carried within the chamber. The apparatus further comprises a cap or lid for engaging and closing the opening of the chamber-forming means to define a closed waste treatment chamber, and a liner carried within the processing chamber for preventing biological waste from adhering to the cap or lid as a result of its treatment within the waste treatment chamber.

Preferably, an indicator means is carried by the liner within the processing chamber for indicating the presence of decontaminant in the cycle.

More specifically, a preferred apparatus includes a chamber-forming means having a bottom and a cylindrical sidewall forming, by an opening interface, an upper opening. The cap of the waste treatment assembly comprises a lid with a central panel having a circumferential lip for receiving an O-ring. The opening interface of the chamber sidewall forming the upper opening of the chamber more specifically comprises a peripheral flange disposed at the upper edge of the sidewall of the processing chamber circumferentially about the upper opening. The flange is selectively dimensioned so as to be received within the circumferential lip of the cap to engage the O- ring therein.

The liner, and, preferably an indicator means, are adapted to be carried by the apparatus to separate the underside of the lid from the processing chamber by pressure surfaces of the lid and chamber sidewall when the lid sets atop the sidewall of the chamber. The apparatus further includes means, such as a plurality of latches, for securing the lid over the upper opening of the chamber and for effecting sealing engagement of the lid, chamber sidewall and O-ring. In a preferred apparatus of the invention, the waste treatment chamber includes a HEPA filter carried by the lid and the liner is gas pervious to permit the escape of air and water vapor from the chamber during the operation.

The indicator is preferably a chemical-sensitive indicator carried within the interior of the chamber that reacts to a decontaminant during waste treatment within the chamber and generates an output by a color change indicating that decontaminant was present. Preferably, the indicator is carried by the liner adjacent the underside of the cap.

Other features and advantages of the disclosed embodiments and methods of the invention will be apparent from the drawings and more detailed description of the invention that follows.

Brief Description of the Drawings Fig. 1 is a perspective view of a fully assembled waste collection and processing apparatus that may include the invention;

Fig. 2 is a partially cut-away perspective view to show a use of the invention in the apparatus of Fig. 1;

Fig. 3 is an exploded perspective view of the apparatus of Fig. 2 to show the invention more clearly;

Fig. 4 is an enlarged, isolated partial cross- sectional view of the interface between the cap, the liner, the O-ring and the upper edge of the sidewalls of a portable processing chamber to more clearly show this invention; and Fig. 5 is an enlarged, isolated partial cross- sectional view of the cap, filter and liner of the apparatus as shown in Fig. 2.

Best Mode for Carrying Out the Invention

For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

Referring now to the drawings, and particularly to Figs. 1 and 2, a waste treatment apparatus 10 includes a chamber-forming means 20, preferably including a bottom wall 22 and an upwardly standing, generally cylindrical sidewall 24 with a circumferential upper edge 54 forming an open top 26. Chamber-forming means 20 can be made integral or can include a lower kettle-like housing 52 and a top cylindrical housing 53, both of which are symmetrical about a central axis 55.

Where, as shown, chamber-forming means 20 includes a lower kettle-like housing 52 and a top housing 53, lower housing 52 can have an outwardly turned upper circular flange 52U (Figs. 2 and 3) supporting a first O-ring 56 which engages the circular bead 53a at the bottom of the top housing 53. The top and lower housings 52,53 can be fastened together by base latches 57 defined by over-center. lever operated, spring clamps such as are available from Dzus Fasteners of West Islip, New York 11795. The bottom of lower housing 52 preferably can have four circularly spaced feet 58. These feet 58 support the flask assembly on a counter and while disposed in a main power cabinet and also prevent the chamber- forming means 20 from rotating while operatively disposed in the main power cabinet. Pairs of U-shaped handles 111 and 211 may be provided on the sides of the lower housing 52 and upper housing 53, respectively, for purposes of handling and transporting the apparatus 10.

As shown in Fig. 2, a rotatable waste treatment assembly 61 is carried within chamber-forming means 20. Such a waste treatment assembly may comprise an impeller assembly 61 mounted adjacent the bottom floor 22 of the lower housing 52. The rotatable waste treatment assembly 61 can be supported by a bearing mount cylinder (not shown) which can be welded to the bottom 22 of lower housing 52 around a central opening (not shown) provided in the bottom 22. Inasmuch as the manner in which the waste treatment assembly 61 is constructed, or driven or is carried within the chamber forms no part of the present invention, such details are not given here; however

U.S. Patent Nos. 5,236,135 and 5,240,187 describe such waste treatment apparatus.

In the treatment of biological waste with such apparatus, the cap or lid 102 is removed from the chamber-forming means 20 and biological waste to be treated is placed in the chamber-forming means 20, preferably with a decontaminant solution. The cap or lid 102 is then replaced and secured to the chamber- forming means 20 by one or more fasteners 157. The apparatus 10 is then connected with a power unit. which, in operation, rotates the waste treatment assembly 61. Rotation of the waste treatment assembly disintegrates the biological waste by pulverizing and blunting solid waste and cutting and tearing soft waste and washes the waste particles with decontaminant solution.

In operation, however, the waste particles are thrown about in the chamber-forming means 20 and many such particles are thrown against and may adhere or cling to the underside of lid 102. When the lid 102 is subsequently removed from the chamber-forming means 20, generally at the conclusion of treatment of the waste material, waste particles that may adhere to the underside of lid 102 may be dislodged as, or after, lid 102 is removed from the chamber-forming means 20 and fall uncontrolled on surfaces adjacent the apparatus 10. Such waste particles present a cleaning problem, and, if, for some reason, treatment is stopped and lid 102 is removed from the apparatus before decontamination has been completed, such escaping waste particles may also present a decontamination problem to avoid exposure of personnel to possibly undecontaminated biological waste.

The invention provides such a waste treatment apparatus, as shown in Figs. 2-5, with means for preventing waste particles from adhering to the underside of the lid as a result of operation of the apparatus, and, preferably, with means for indicating to personnel whether decontaminant was present in the cycle when the lid is removed from the apparatus and before operating personnel are exposed to waste materials within the waste treatment chamber.

Referring particularly to Figs. 3 and 4, the top housing 53 of processing chamber 20 includes a cap or lid 102 having a central panel 103 and a generally circumferential edge or lip 105. Lip 105 comprises a downwardly facing U-shaped cross section, as shown in Fig. 4 to receive an O-ring 156. Lid 102 is positioned atop and fastened via clamps 157 to the top housing 53 thereby closing upper opening 26 of chamber 20.

The opening 26 of the upper housing 53 is more specifically formed by an opening interface in the form of a circumferential flange 54 (Figs. 3 and 4) selectively dimensioned so as to be received within the downwardly facing U-shaped lip 105 of cap 102. Referring particularly to Fig. 4, lid 102 further includes a downwardly-facing pressure surface 107 defined by the transition interconnecting the central panel 103 to the circumferential lip 105 of cap 102. The opening interface 54 of the upper housing 53 includes an upwardly facing pressure surface 54b. The upwardly facing pressure surface 54b is formed outwardly from the sidewall of top housing 53 and provides a transition interconnected with a generally planar circumferential annular flange portion 54c. Pressure surface 107 of cap 102 coacts with the pressure surface 54b to engage therebetween the circumferential edge 104a of liner 104, thereby providing means for securing the liner 104 in position to separate the underside of cap 102 from the processing chamber. O-ring 156 is engaged in a sealing relationship within the peripheral lip 105 of cap 102 by the circumferential annular flange portion 54c of the opening interface 54 to prevent the escape of material at that interface.

Means for preventing adherence of waste material particles to the underside of lid 102 is thus provided by a liner 104 disposed adjacent the underside of cap 102 to prevent waste material particles from being thrown against and adhering to the underside of the cap. In the preferred embodiment shown, a plenum-like space 106 is formed between cap 102 and liner 104. Cap liner 102 is preferably formed by a gas-permeable material that permits the closed processing chamber 20 to breath through the entire cap liner 102 and ultimately through a HEPA filter 108 during operation of the apparatus. One preferred gas permeable liner material is Filter Fabrics Inc., No. 8060 Spunbonded Polyester.

Preferably, an indicator means 120 (Fig. 3) is carried within the interior of chamber 20 by the liner 104. Indicator means 120 is preferably a chemically sensitive indicator that reacts to decontaminant in the processing chamber during operation to generate a color-change output signal indicating that the decontaminant was present in the chamber. Preferably, the indicator 120 is carried by the top of the liner 104 to be readily observable to a person when the lid 102 is removed and before processing chamber 20 is completely opened by removal of liner 104. Alternatively, the indicator 120 can be impregnated into the liner 104. The selection of an indicator material depends, generally, upon the decontaminant material that is used to treat the biological waste. When used with a decontaminating agent including peracetic acid, one such suitable chemically sensitive indicator is Peracetic Acid Indicator manufactured by Serium Research located in Elkhart, Indiana, and having a product name Chronegenic Oxidation Sensitive Indicator.

Heat generated within the chamber during operation often creates an expansion of the air and water vapor within the chamber. As indicated above. such apparatus generally includes a removable HEPA filter 108 for permitting the passage of air and water vapor from within the processing chamber 20 while preventing passage of aerosols and fine particulate matter. As shown in Fig. 5, filter 108 includes a lower portion 109 that extends through a central opening (not shown) provided in cap 102. Filter 108 preferably comprises a high-efficiency particulate air (HEPA) filter of the type sold by Gelman Sciences Membrane Filter Division. Portion 109 extends downwardly below the central panel 103 of cap 102 and may be held in place in the opening provided in the cap by an O-ring or other suitable connection means to prevent material from escaping at that interface. When used in combination with a main power unit such as that described in U.S. Patent No. 5,236,135 and 5,240,187, the portable processing chamber 20 is removed from the main power unit after treatment by simply lifting the processing chamber 20 out of the main power unit by use of the handles ill or 211, one in each hand. The chamber 20 can then be moved to whatever site location is convenient for disposal of treated waste material therein.

Upon removal of lid 102, personnel can observe the indicator 120 to determine if decontaminant was present. If decontaminants were not present, corrective action can be taken, e.g. the addition of decontaminant, and the treatment cycle can be repeated. If decontaminant was present or decontamination has been effected, liner 104 will be removed and disposed of automatically as the liner and treated waste material particles are "poured" from the processing chamber 20 through its upper opening 26 into containers for disposal. While a presently preferred embodiment and best mode of the invention has been illustrated and described in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it is to be understood that the invention is defined by the following claims and the prior art and that all changes and modifications that come within the scope of the following claims are to be protected.

Claims

What is Claimed is:

1. An apparatus for the treatment and decontamination of biological waste, comprising: a chamber-forming means enclosing a rotatable waste treatment assembly accessible through an opening formed by an opening interface; a cap for engaging said opening interface and closing the opening of said chamber-forming means to define a closed waste treatment chamber; a gas-pervious liner carried within the chamber-forming means for preventing biological waste from adhering to said cap; an O-ring disposed between said cap and said opening of said chamber-forming means and around said opening for sealing said opening interface; and indicator means carried within said chamber- forming means for indicating the decontamination of said biological waste.

2. The apparatus of claim 1 wherein said indicator means comprises a chemical indicator carried by the liner, said chemical indicator being adapted to change color during operation of said apparatus when the presence of decontaminant is detected.

3. The apparatus of claim 1 wherein said cap comprises a central panel and a circumferential lip for receiving therein said O-ring for engagement with said opening interface.

4. The apparatus of claim 3 wherein said opening interface of said chamber-forming means is formed by a flange disposed circu ferentially about said opening, said flange being selectively dimensioned so as to be received within the circumferential lip of said cap to sealingly engage said O-ring.

5. The apparatus of claim 1 wherein said cap 5 includes a first pressure surface disposed circumferentially about a central panel, wherein said opening interface of the chamber-forming means is formed by a second pressure surface of said chamber-forming means disposed 10 circumferentially about said opening, and wherein said liner is dimensioned so that, when carried within said chamber-forming means, the circumferential edge of said liner is held between the first and second pressure surfaces, thereby releasably 15 securing the liner in position covering the central panel of said cap.

6. The apparatus of claim 1 further comprising a high efficiency particle air filter permitting the

20 passage of air and water vapor from within said chamber, said filter including a portion extending through an opening provided in said cap.

7. The apparatus of claim 1 further comprising 25 a plurality of latches for securing said cap to said opening interface with said O-ring disposed therebetween.

8. The apparatus of claim 1 wherein said ' 30 chamber-forming means comprises a bottom and a sidewall with said opening at its top, and wherein said cap comprises a lid arranged to carry said O-ring and to set atop the opening interface of said chamber-forming means, and further 35 comprising means for securing said lid to said chamber- forming means and for effecting sealing engagement of said lid, O-ring and opening interface.

9. The apparatus of claim 8 wherein said gas- pervious liner is carried by said lid through engagement of said liner by first and second pressure surfaces of said lid and sidewall, and wherein said securing means also effects retention of said gas pervious liner between said lid and chamber-forming means.

10. In a waste treatment apparatus for the treatment and decontamination of waste, said apparatus including a generally cylindrical body having a bottom, an upwardly standing sidewall, and an open top with a circumferential upper edge, a removable lid having a generally circular circumferential edge for closing the open top of said apparatus body thereby defining, in combination with said bottom and body, a closeable chamber for the treatment and decontamination of waste by a contained rotatable waste treatment assembly, and means for releasably securing the lid over the open top of said body, the improvement comprising: a liner interposed between said lid and the upper edge of said body for preventing waste from adhering to the underside of said lid as a result of its treatment in said chamber.

11. The waste treatment apparatus of claim 10 wherein the improvement further comprises means for indicating when decontamination of the waste in said chamber has been effected.

12. The waste treatment apparatus of claim 11 wherein said indicator includes a chemical-sensitive indicator carried within the interior of said chamber that reacts to a decontaminant solution in the chamber by generating an output indicating the presence of the decontaminant.

13. The waste treatment apparatus of claim 12 wherein said indicator is carried by the top of said liner, or is impregnated into said liner to be visible from either side of said liner.

14. The waste treatment apparatus of claim 10 wherein an O-ring is interposed between said lid and the upper edge of said body for providing a sealing engagement between said cap and the upper edge of said body.

15. The waste treatment apparatus of claim 14 wherein the improvement further comprises the upper edge of said body and a circumferential edge of said lid providing pressure surfaces for receiving and securing therebetween the outer circumferential edge of said liner.

16. The waste treatment apparatus of claim 14 wherein the improvement further comprises circumferential edge of said lid including a downwardly facing peripheral pressure surface adjoining a downwardly facing U-shaped peripheral O- ring flange, and the upper edge of said body including a upwardly facing peripheral pressure surface adjoining a generally planar annular flange to said sidewall of said chamber body. said downwardly facing peripheral pressure surface of the lid abutting, when the lid is positioned over the open top of the chamber body, the upwardly facing peripheral pressure surface of the upper edge of said body and securing therebetween the outer peripheral edge of the liner so that said liner is retained in position to separate the underside of said lid and said chamber, said O-ring being disposed within the downwardly facing U-shaped peripheral flange of said cap and being engaged by the generally planar annular flange of the upper edge of said chamber body.