Automated liquid sterilization system

• US 4,731,222 A
• Filed: 02/06/1986
• Issued: 03/15/1988
• Est. Priority Date: 02/06/1986
• Status: Expired due to Term

• Current Assignee: Innovative Medical Technologies Incorporated
• Original Assignee: Innovative Medical Technologies Incorporated
• Inventors: Schneider, Edward T., Kralovic, Raymond C.
• Primary Examiner(s): Richman, Barry S.
• Assistant Examiner(s): Johnston, Jill
• Application Number:
  US06/826,730
• Time in Patent Office: 768 Days
• Field of Search: 422/37, 422/905, 422/292, 422/307, 422/28, 422/116, 422/300, 204/147, 204/148, 204/196, 204/197
• US Class Current: 422/37
• CPC Class Codes: A01N 25/34 Shaped forms, e.g. sheets, not provided for in any other sub-group of this main group
• CPC Class Codes: A61L 15/44 Medicaments
• CPC Class Codes: A61L 15/46 Deodorants or malodour counteractants, e.g. to inhibit the formation of ammonia or bacteria
• CPC Class Codes: A61L 2/16 using chemical substances
• CPC Class Codes: A61L 2/18 Liquid substances or solutions comprising solids or dissolved gases
• CPC Class Codes: A61L 2/20 Gaseous substances, e.g. vapours
• CPC Class Codes: A61L 2/22 Phase substances, e.g. smokes, aerosols or sprayed or atomised substances
• CPC Class Codes: A61L 2/24 Apparatus using programmed or automatic operation

Abstract

Each of a plurality of modules (A) have fittings (14) with automatically closed check valves (16) therein such that the interior of the module is hermetically sealed. The module is selectively interconnected with a sterilizer apparatus (B). Interconnecting tubing (60) selectively supplies liquid from a reservoir (30) to the module. A sterilant injection chamber (56) receives and punctures a sterilant ampule such that incoming water mixes with the sterilant concentrate forming a sterilant solution which is carried to the reservoir. A reservoir outlet valve (70) selectively permits the sterilant solution to pass from the reservoir through the interconnecting tubing into the module until the module and interconnecting tubing are completely filled. Thereafter, the reservoir outlet valve closes holding the sterilant in the interconnecting tubing as well as the module for sufficient duration to sterilize both. Concurrently, additional tap water is heated in the reservoir until it is sterile. Thereafter, the reservoir outlet valve is opened again and the sterilant solution is drained and rinsed from the module with the sterile water. An air pump (86), a heater (84), and a submicron sterilization filter (82) supply heated, sterile drying air through the reservoir, connecting tubing, and module to dry the sterilized device.

Claims

1. A method of sterilizing medical instruments, the method comprising:

disposing a medical instrument to be sterilized in a storage module;

closing the module to penetration by microbial contamination;

removably attaching the storage module with tubing which interconnects the attached module with a source of liquid rinse solution;

completely filling the interconnecting tubing from the module to the rinse solution source and the module with a liquid sterilant;

retaining the liquid sterilant in the module and the interconnecting tubing for a preselected duration, which preselected duration is sufficiently long to sterilize the module, the medical instrument, and the interconnecting tubing;

passing a sterilized liquid rinse solution from the rinse solution source only through the sterilized interconnecting tubing into the sterilized module to rinse the liquid sterilant from the interconnecting tubing, the module, and the medical instrument, whereby the liquid rinse solution passes only in contact with sterilized surfaces to prevent contamination of the liquid rinse solution;

detaching the module from the interconnecting tubing while maintaining the module closed to microbial contamination; and

,

storing the module and the medical instrument as a unit.

2. The sterilization method as set forth in claim 1 further including mixing a sterilant concentrate with tap water to form the liquid sterilant.

3. The sterilization method as set forth in claim 1 further including:

during the liquid sterilant retaining step, passing an electrical current between the medical instrument to be sterilized and an electrode in an electrical conductive relationship with the liquid sterilant to inhibit galvanic corrosion.

4. The sterilization method as set forth in claim 1 wherein the liquid sterilant includes a hypochlorite, a buffer, a detergent, and water.

12. The apparatus as set forth in claim 1 further including:

a sterilant injection chamber for selectively receiving a charge of a sterilant concentrate and mixing the charge with a liquid to form the liquid sterilant, the sterilant injection chamber being interconnected in fluid communication with the interconnecting tubing for supplying the liquid sterilant into the interconnecting tubing and the connected module.

5. A method of sterilizing items comprising:

(a) enclosing an item to be sterilized in an interior of a module which is closed to penetration of microbial contaminants from the ambient atmosphere;

(b) removeably attaching the module with tubing that connects the module with a source of sterile rinse liquid;

(c) causing a liquid sterilant to flow into and remain in contact with the module interior and the tubing which connects the module with the source of sterile rinse liquid until the item and the module interior are sterilized;

(d) draining the liquid sterilant from the module interior;

(e) passing a sterile rinse liquid from the source thereof into the module interior to rinse the item;

(f) detaching the module while maintaining the module closed to microbial contaminant;

(g) storing the item in the module to retain the item in a sterile condition

6. The method as set forth in claim 5 further including after step (e), passing a bacteria-free gas into the module interior.

9. The method as set forth in claim 5 wherein the liquid sterilant is a solution including a hypochlorite, a buffer, a detergent, and water.

7. A method of sterilizing comprising:

enclosing an item to be sterilized in a sterilizing chamber which is isolated from microbial contamination from the ambient atmosphere;

providing interior surfaces which define a liquid rinse flow path between the chamber and a source of sterile rinse liquid;

causing a liquid sterilant to flow into the chamber and into all flow path interior surfaces which define the interconnecting flow path from the sterile liquid rinse source into the chamber and every interior surface in direct fluid communication therewith;

retaining the liquid sterilant in the chamber and the flow path interior surfaces until the flow path interior surfaces, the item, and the chamber are sterilized, whereby sterilizing all surfaces between the rinse fluid source and the chamber assures that the liquid rinse fluid will not carry microbial contaminants from non-sterile surfaces into the chamber;

draining the liquid sterilant from the chamber and the interconnecting flow path;

passing the sterile liquid rinse fluid from the liquid rinse source only in contact with the sterilized flow path surfaces into the chamber to rinse the item;

draining the liquid rinse fluid from the chamber and the interconnecting flow path.

8. The method as set forth in claim 7 wherein the liquid sterilant is a solution including a hypochlorite, a buffer, a detergent, and water.

10. The method as set forth in claim 7 further including during the draining step, passing bacteria-free air into the chamber to dry the item and the chamber interior.

11. A sterilization apparatus comprising:

a source of liquid rinse fluid;

a sterilizing means operatively connected with the source for sterilizing the liquid rinse fluid;

a module including a closure means which has opened and closed configurations therefore, where in the opened configuration, said module is opened to receive an item to be sterilized, and in the closed configuration, said module isolates the received item from the ambient atmosphere and other sources of microbial contamination;

a detachable module interconnecting means;

interconnecting tubing detachably connecting the source and said module with the detachable module interconnecting means;

means for selectively filling both the interconnecting tubing and the connected module with a liquid sterilant; and

means for selectively keeping the interconnecting tubing and the module filled with the liquid sterilant for a sufficient duration to sterilize the module, the item, the module interconnecting means and the interconnecting tubing from the source to the module.