WO1998024007A1 - Single line automatic fluid delivery system for dental unit water line treatment - Google Patents

Single line automatic fluid delivery system for dental unit water line treatment Download PDF

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Publication number
WO1998024007A1
WO1998024007A1 PCT/US1997/022697 US9722697W WO9824007A1 WO 1998024007 A1 WO1998024007 A1 WO 1998024007A1 US 9722697 W US9722697 W US 9722697W WO 9824007 A1 WO9824007 A1 WO 9824007A1
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WO
WIPO (PCT)
Prior art keywords
water
line
delivery
automated
afds
Prior art date
Application number
PCT/US1997/022697
Other languages
French (fr)
Inventor
Jimmy D. Disel
Original Assignee
Aerotech Dental Systems, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to US3231396P priority Critical
Priority to US60/032,313 priority
Priority to US08/795,218 priority patent/US5836483A/en
Priority to US08/795,218 priority
Application filed by Aerotech Dental Systems, Inc. filed Critical Aerotech Dental Systems, Inc.
Publication of WO1998024007A1 publication Critical patent/WO1998024007A1/en

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Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B08CLEANING
    • B08BCLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
    • B08B9/00Cleaning hollow articles by methods or apparatus specially adapted thereto
    • B08B9/02Cleaning pipes or tubes or systems of pipes or tubes
    • B08B9/027Cleaning the internal surfaces; Removal of blockages
    • B08B9/032Cleaning the internal surfaces; Removal of blockages by the mechanical action of a moving fluid, e.g. by flushing
    • B08B9/0321Cleaning the internal surfaces; Removal of blockages by the mechanical action of a moving fluid, e.g. by flushing using pressurised, pulsating or purging fluid
    • B08B9/0325Control mechanisms therefor
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B08CLEANING
    • B08BCLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
    • B08B9/00Cleaning hollow articles by methods or apparatus specially adapted thereto
    • B08B9/02Cleaning pipes or tubes or systems of pipes or tubes
    • B08B9/027Cleaning the internal surfaces; Removal of blockages
    • B08B9/032Cleaning the internal surfaces; Removal of blockages by the mechanical action of a moving fluid, e.g. by flushing
    • B08B9/0321Cleaning the internal surfaces; Removal of blockages by the mechanical action of a moving fluid, e.g. by flushing using pressurised, pulsating or purging fluid
    • B08B9/0327Cleaning the internal surfaces; Removal of blockages by the mechanical action of a moving fluid, e.g. by flushing using pressurised, pulsating or purging fluid the fluid being in the form of a mist
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B08CLEANING
    • B08BCLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
    • B08B2203/00Details of cleaning machines or methods involving the use or presence of liquid or steam
    • B08B2203/005Details of cleaning machines or methods involving the use or presence of liquid or steam the liquid being ozonated

Abstract

An Automatic Fluid Delivery System (ADDS) and method for disinfecting dental or medical unit water delivery lines (DUWL) is disclosed. The automatic timing and sequencing of the disinfection process is provided by a programmable microprocessor employing integrated circuits in a Control Module (10). The treatment solution (22) and rinse medical grade water (21) are contained in bottles of a Bottle Assembly (20), the flow from which is controlled by the microprocessor actuated pneumatic valves, and fluid connection to the dental unit is direct. Other control valving is contained in a Unit Module (30). The use of pinch valves and equal pressurization of the bottles prevents retraction (suck back) of contaminants. The dental unit is made inoperative and locked-out while the ADDS is in operation, and until the DUWLs have been finally purged by water. The ADDS may be retrofit on present dental units or integrated therewith, and used with any device employing consumable water or aqueous solution delivery lines, such as refrigerators, coffee makers, water filtration or treatment systems, food or drink preparations, and the like.

Description

TITLE:
SINGLE LINE AUTOMATIC FLUID DELIVERY SYSTEM FOR DENTAL UNIT WATER LINE TREATMENT
DESCRIPTION
TECHNICAL FIELD:
The present invention relates generally to the field of automated medical and dental appliances, and more particularly to an improved system for antimicrobial treatment of medical and dental unit waterlines which convey water to dental or medical implements or instruments for irrigation and/or cooling and to cuspidor drink cups. The improvement comprises an automated electronic controller unit and a bottle holder and cap/valve assembly that provides multi-mode treatment of water line supply to dental units, with special pneumatic valving and valve control mechanisms and sequences that prevent backflow, including continuously pressurized medical (sterilized) water supply bottle. BACKGROUND OF THE INVENTION:
Modern dental treatment units (herein "dental units", or abbreviated "DU") employ electricity for illumination, air for pneumatic power, and water for cooling and/or irrigation where a dental tool contacts teeth, bone or gums, and for rinsing. The water supply can be provided either from city water or from a closed deionized or sterilized water system. However, in either system, once the dental instrument, accessory or cup is replaced in a cradle after use, the remaining water stagnates in the dental unit feed and delivery lines, which are generally more than three feet long, and in the associated control valves and feed reservoirs. The water rapidly becomes contaminated by microbial populations, forming a "biofilm", a consortium of microbial populations in a cellular nutrient slime matrix. Such a thick slimy film can be partially broken free from the lines with high pressure water or air and comes out of the lines as a paste. In some cases, the lines become completely plugged. Although the instruments and accessories can be removed and sterilized as separate components, it has not been feasible to sterilize the built-in portions of the dental unit such as water delivery and feed lines except by laborious manual flushing.
It has been recognized that such microbial contamination is a serious health hazard during surgical and dental cleaning procedures, due to the fact that patients and healthcare professionals are exposed to delivery of the contaminated water directly at the site of the surgical or dental procedure, or by aspiration of fine water spray droplets. This problem of dental unit waterline (DUWL) bacterial contamination is discussed in an article by Andrews, N., Dental Unit Waterline Contamination, in Practical Hygiene, July/Aug. 1994, pp. 11-20. The problem is widespread and serious, with DUWL bacterial populations frequently exceeding EPA and U.S. Army standards for potable water. Andrews concludes that flushing with water at best has proven an unreliable method of cleaning water lines, particularly if any biofilm is present. It is fair to conclude from the Andrews article that , absent treatment, formation of biofilm is impossible to prevent. In addition to delivery of pathogens to patients and health care workers by direct contact (lavage) of open tissue, bacteria is also communicated by aspiration of contaminated water, inhalation of aerosol droplets and ingestion (swallowing). The patients are not the only persons at risk. The scientific evidence suggests dental clinicians receive significant long term exposure to DUWL microbes. Indeed, there are anecdotal reports of DUWL microbial exposure contributing to the deaths of several dentists. Microbial contamination is measured in CFU, bacterial Colony Forming Units/mL, with the U.S. Public Health Service 1914 potable water standard for interstate carriers being <100 CFU/mL, non-potable at 500, rain water ranging from ~5-19, snow from -0-463, spring water ~41 , unpolluted river water 64, polluted river water 2000-3.4 million, and raw sewage 1 million to 10 million. Against this, DUWL water has been measured in the range of 0-1 million, and home use reverse osmosis system at 1 ,000 to 100,000. Dentistry Today magazine reported 72% of DUWL samples were classified as unfit for human consumption, i.e. >500 CFU/mL. The mean counts for heterotrophic organisms were 49,700 from 3-way syringes, 72,000 from handpiece lines, and 19,800 from sealer lines.
A wide range of bacterial, protozoan and viral species are present in such "consumable" water, including: Staphylococcus aureus; Streptococcus spp; Pseudomonas; Legionella; Aeromonas; Acineobacter; Alcaligenes; Mycobacteriumsp.; Amoebae (Harimanella,Naegleria, etc); pathogens such as A. polyphaga; fungi such as Candida; nematodes such as Rhabditia. Dr. Jeffrey Williams, a microbiologist at Michigan State University, interviewed on WISN-TV (ABC) Channel 12, Milwaukee, WI, on November 28, 1995 reported DUWLs tested by him contained, among others, Pseudomonas, Streptococcus, Staphylococcus, Legionella and HIV microbes, and that patients could end up with pseudotyphus, hepatopoulous, pneumonia, pharyngitis, localized infections, abcesses, and AIDS.
Prior art efforts at addressing this problem have included the employment of closed water systems using sterilized water. However this is less than a suitable long term remedy, since the environment, principally tubing, through which the water is introduced and used is not sterile, and contamination will eventually occur. Even relatively pure city water contains some bacteria. Thus, where city water is used in the system the problem is exacerbated and accelerated.
Prior to the present invention, the only way to clean dental unit delivery tubes and feed water supply has been to disconnect and remove any accessories (e.g., handpieces) from the dental unit (for separate disinfection), and then go through a laborious and unreliable procedure of introduction and passage of disinfecting fluids through the delivery tubes and feed water supply. According to such methods, the degree of cleansing depends upon the competence of the personnel doing the cleaning and conscientiously adhering to a rigorous cleaning schedule. Under the time constraints of modern dental practice, the procedure is often shortened or neglected, if not omitted entirely.
In addition to the usual dental drills, syringes and drink cups, ultrasonic sealers are in wide use in dental offices to remove calculus, old cement, tartar stains, etc. These accessories are connected to the dental unit water flow system during use to keep the tip cool, flush the work area, and assist in transmission of ultrasonic frequency energy. They are employed below gum line, e.g., in cases of gingivitis, abscesses, root canal work, etc. Likewise, non-ultrasonic sealers and air polishing units use a combination of air, water and abrasive to clean and polish teeth. Accordingly, microbial populations developing in the water delivery and feed tubes of the dental unit, and its accessories, e.g., between periods of use (stagnation), can be delivered through the dental unit and accessories water supplies to open tissue. Manual flush systems for dental unit handpiece and syringe hoses are currently available from: Forest Dental, Hillsboro, OR; Ampco Dental, Grover City, CA; Adec Dental Manufacturing, Newberg, OR; Dental Components, Inc. (DCI), Newberg, OR; Dental-EZ, Valley Forge, PA; Rembrandt, Santa Maria, CA; and PROMA, Carson, CA, among others. They employ separate water and/or solution lines and do not have true anti-backflow (anti- retractive) valves). Even with such manual systems, poor, inconsistent or intermitted operations result in development of a biofilm coating on the insides of the lines, which includes bacteria, fungi and protozoa.
Some DUWL treatment systems propose the use of in-line filters fitted within 10" of the end of the handpiece and syringe water supply line. The filter must be removed manually at the end of each 8-hour period (used or not), and the lines filled with disinfectant by use of a manual syringe and left overnight. Even after installing fresh filters, the CFU count can rise to 14,000 within 3 hours. Filter systems at best only treat a portion of handpiece and syringe hoses, and do not offer safety lockout features preventing disinfectant from reaching patients. Where filters are used, they must be changed every 8 hours or sooner to be consistently effective. Since filters trap bacteria on the upstream (inlet) side, they gradually get plugged, requiring increased pressure to deliver constant flow in the line. The biofilm slime can break through for usage longer than 8 hours, and clots of microbial contaminants can be passed to the patient or dental professional. As with manual systems, filters are not cost effective, running about $2 each. For a dental office with 3 chairs this results in an annual cost of over $5,700 for the filters plus 20-60 minutes for each filter change-out each day. The person performing maintenance must wear protective gloves and mask as the filters are highly contaminated, must then properly dispose of the contaminated filters using approved hazardous etiological materials disposal protocols, inject sterile solution, leave over night, the next day drain solution, and install new filters using sterile procedures. Many chairs have multiple handpieces, and each must be changed every 8 hours. For off-hours emergency treatment, the change out procedure must be completed before the dental chair is brought back on line.
Some manual systems are switchable between city water to purified water, which permits transfer of microbial contaminants to the system from the city water. Some manual systems use in-line check valves, but biofilm will build up in the valves causing them to leak, permitting downstream contamination and water retraction suck back.. Operating manual DUWL flush systems is labor intensive requiring 20-30 minutes at the end of each day to complete the flushing process for each dental chair, and they must be diligently monitored, e.g., for bottle change-out.
Accordingly, there is a need for a single line automated electronic DUWL flush system that uses medical grade or sterile water and has special backflow preventing valves and dental unit lockout control systems. This system needs to be low in cost, simple to operate, relatively fool proof, include lockouts to prevent interruption of cleaning cycles, be easily programmable for changes in step sequences, frequency of treatment, etc., and which can be automatically cycled at the end of or before dental procedures, and/or cycled automatically according to a regular schedule.
DISCLOSURE OF THE INVENTION
It is among the objects and the advantages of the present invention to provide a single line Automatic Fluid Delivery System (herein also referred to as "AFDS") for antimicrobial slime and biofilm control for water delivery and supply lines to medical/dental instruments and accessories, which system is automatic and easy to operate and may be retrofitted to current dental units. It is another object and advantage of the invention to provide an electronic AFDS antimicrobial slime control system which can be programmed to be cycled in a plurality of modes at the beginning and/or at the end of every procedure. It is another object and advantage of the present invention to provide an electronic AFDS for biofilm or slime control which has built-in safeguards (lock-outs) to prevent misuse, does not depend on the diligence or skill of the dental technician, and may be dedicated to service a single dental chair unit or medical station, or provided as a single larger system hooked in parallel via a manifold system to a plurality of dental chair units in one dental or medical office. It is another advantage of the AFDS system of this invention that it employs a single line for sequentially supplying medical grade or sterile water and disinfectant solution, which water bottle is always pressurized when the unit is on, and which employs special electronically controlled pneumatic valves in a unique valving and line circuit to prevent or reduce backflow, and which permits multiple cycle modes with multiple sequences of one or more disinfectant or treatment solutions, and one or more types of rinse solutions, preceeded and/or followed by air purge, and lockout of the dental unit until retreatment of the line just before the next patient procedure. The present invention is directed to a system and method for the provision and complete internal treatment of the water supply and delivery system for medical and dental units, particularly those used with dental instruments and sealer units. More particularly, the invention comprises a single line DUWL treatment apparatus and method for control of microbial slime and/or biofilm growth in a water line. In the current best mode embodiment, the valves, controls, components and connectors of the AFDS are grouped for convenience and efficiency in three modules: (1) "AFDS Control Module" or "CM"; (2) "Bottle Assembly" or "BA"; and (3) "Unit Module" or "UM". These three modules are interconnected to each other and to the dental unit by a number of tubes (preferably arranged in bundles) for a compressed air supply, fluid delivery and pneumatic control signals. No liquid lines are routed to or through the CM so that its board and/or face plate can be mounted anywhere convenient in relation to the Dental Unit.
The AFDS system of this invention is characterized by employing a programmable electronic controller for electronic and pneumatic timed control of air signals to pneumatic pinch valves which sequence the operations of the AFDS during predetermined treatment cycles. The controlled air signals initiate: locking out the DU operation (e.g., foot control) or complete DU) during treatment cycles, switching bottles from medical grade water for normal DU operation to treatment solution for the predetermined time period, introducing air for purge at the beginning, middle or end of the treatment cycle, sequenced opening and closing drain valves to the DU water lines to permit flushing, rinsing and purging those lines to the handpieces, syringe and other accessories (e.g. cavitron); and triggering cycle status, fluid level (inventory) and completion indicators (e.g., LEDs and/or audible alarms). No liquid line passes through the Control Module.
The preferred embodiment of the invention provides antimicrobial treatment solution from a supply bottle, and medical grade water, preferably sterile, from another supply bottle, both in the Bottle Assembly. The term "single line" refers to the fact that there is a single liquid line from the AFDS Bottle Assembly for sequentially supplying medical grade water disinfectant /treatment solution and optional air purge to the DU and accessory lines. Preferably there is no alternate supply of city or public water to the dental unit as consumable water. After treatment and during normal operation, the AFDS supplies medical grade or distilled water to the DU. By "consumable" water is meant water used, expended, or consumed, once in operation of a delivery device, for example, single use process water such as: water for dental lavage or rinsing; a coffee maker producing a cup of coffee; a water purifier, cooler or ice maker dispensing water or ice; food or drink ingredient water; or the like. The DU delivery system, which is typically an arm-mounted console having multiple instrument connections and also called the DU console, includes an internal water delivery system which branches though valves and controls to multiple hoses or lines to serve the handpieces, cup filler, syringe, scaling units, and other accessories. Check valves (anti-siphon valves) are employed in the DU at various locations, depending on the manufacturer's design preferences, to prevent back-flow of water from handpiece to the DU consumable water line. Biofilm will render a check valve ineffective in 3-5 days. By replacing the DU coolant valve (13 in Fig. 2) with a pinch valve of Fig. 9, a water line check valve is eliminated. The multiple lines of a DU delivery system are supplied by the single line from the AFDS Bottle Assembly supply bottles, and all may be treated by the AFDS system of this invention. The water bottle in the BA is continuously pressurized when the AFDS is on and when the DU is used while the AFDS is off. This preferred single line feature insures both a hygienic water source as well as the maintenance of hygienic dental unit water delivery lines, and this single line is itself treated during each treatment cycle.
The use of only medical grade or sterile water in dental units is preferred, both for hygiene and to comply with increasingly stringent regulatory provisions intended to prevent microbial contamination. However, the AFDS of the invention can be adapted for use with a public water supply, or for the use of both medical grade and public water, or for use with multiple supply lines, should this be desired, such as for certain non-dental uses. Also, public water may be appropriate for specific accessories such as cuspidor flush water, where no patient contact occurs.
The AFDS may be adapted to use multiple disinfectant/treatmentsolutions in sequence, or additional special purpose solutions, should this be desired, rather than the single treatment solution of the current best mode. One of ordinary skill in the art can adapt the AFDS of the invention to include the necessary additional solution supplies and control valves for such purposes. The system is also adaptable to many other uses involving the controlled or automated delivery of aqueous or non-aqueous fluids or gases, in addition to the principal use in hygienic water supplies, and can be adapted to be operated by means of a gas other than air, such as an inert gas. In the best mode embodiment of the AFDS, the Controller Module, Bottle Holder Assembly, and dental unit system controller interface (UM) include novel valve designs, valve and line circuits, pneumatic and electronic valving and a programmable electronic controller with electronic timing. These features permit, in a single line system, a medically safe water supply for patients and dental professionals, as well as a multi-mode cycle for water line treatment/disinfection. The multi-mode feature provides for a disinfect/rinse/standard cycle ("AM cycle", ready for immediate use), disinfect rinse/optional air-dry cycle ("PM cycle", to maintain hygienic water line condition during periods of non-use) and optional pre-cycle air purge modes. The AFDS electronically controls the delivery of treatment disinfectantsolution, rinse water and air in the appropriate sequence and for the appropriate time. While the AFDS is shown as a two-bottle system, it is easily adaptable to a single bottle system or a three or more bottle system. In a one-bottle system, the solution is both an antimicrobial and is ingestible (in small quantities) food grade solution, such as a mouthwash, Bio-2000 (Mycrilium Labs) or the like. Optionally, the PM cycle may include leaving the dental unit supply line filled with disinfectant (or a special purpose bio-septic fluid) during periods of non-use rather than leaving the line air dry or gas filled. In another option, the AFDS may be programmed to provide a single all-purpose mode in which the solution is automatically retained within the dental unit delivery system (console) following the timed treatment period until an operator initiates a rinse cycle. In this alternative, the hold time can either be a prolonged period such as overnight, weekend, or vacation period, or may be essentially zero, as when the operator desires immediate rinse and readiness for use.
Furthermore, a number of important safety and lockout features are included in the preferred best mode AFDS. These include a lockout of the dental unit foot control (the dental unit foot control is a foot-operated variable air regulator by which a dentist controls high speed dental drills and other such instruments) during the disinfection/rinse cycle, a positive valve lockout and depressurization of the disinfectant/treatment solution bottle during DU patient water use, and a positive lockout of the medical grade water container (still under pressure) during solution cycle (preventing any possible solution back-flow). In addition, the medical grade water bottle is constantly maintained at a positive pressure when either the Dental Unit or AFDS is on, which pressure is always at least equal to the pressure in the single delivery line and solution bottle, in order to avoid any tendency towards backflow contamination of the medical grade water by solution.
In addition, as a preferred safety feature of the dual cycle mode, there is a DU foot control lockout following the PM cycle until a subsequent AM cycle is completed. Likewise, the optional drying air connection for the PM cycle is positively locked out except during air- dry operation, preventing any fluid back-flow into the AFDS pneumatic system or DU air supply. The controller also includes operational mode and cycle status indicators, preferably Light Emitting Diodes (LEDs) for operator convenience, and mode and cycle switches.
The system prevents the Dental Unit from operating, i.e. it remains locked out until both the PM and AM cycles are completed. Further, the AFDS will not cycle twice in a row in the PM mode, and the DU cannot be operated after the PM cycle only has been completed. Once the lockout LED indicator illuminates, the DU cannot be used until both cycles are completed.
Important safety lockout features of the AFDS described above provided by the combination of an electronic controller, electro-mechanical primary valves, and pneumatically actuated fluid control and safety lockout valves. An electronic controller times and initiates sequence steps by actuating solenoid primary valves. The "air signals" output from the solenoid valves in turn actuate both the pneumatic valves which control the fluid delivery operation, and other pneumatic valves which control associated safety lockout features.
This control feature insures that the appropriate safety lockouts will be applied automatically upon initiation of a particular fluid delivery operation, such as the release of disinfectant fluid, since the same "air signal" which opens a particular fluid control valve or pressurizes a fluid bottle will also actuate the relevant safety lockouts via use of bi-acting valves. Thus, the safety lockout features are not dependent on any additional or separate actuation by the operator or another electronic controller, and are not vulnerable to electrical failure or software bugs.
The novel valves in all three modules are pneumatically actuated pinch-type valves. That is, medical grade plastic tubes are threaded through the openings in the valve spool or piston and in the valve body between brass pins (rods), one or more being a fixed anvil, and one or more a movable closure pin, such that when activated, they pinch the tube closed. Thus, there are no valve needles, seats, or other parts in a line, around or through which water flows such that these parts can become contaminated with microbial slime or biofilm and wedged partly open, or, conversely, cannot fully close because of slime interference. The fluid within the valve only contacts the smooth inner surface of the tube, a feature which ensures both the hygienic condition and reliable operation of the valves.
In addition, the use of pinch valves reduces or eliminates the requirement for check valves in the fluid connections of the AFDS, since the pinch valves allow virtually no back- flow. Not only do check valves increase cost and complexity, but they are vulnerable to contamination and interference by biofilm which presents closure and permits retraction (suck back).
The geometry of the valve body, piston or spring, pin and anvil system can be conveniently adapted to be normally-open (NO), normally closed (NC), two-way, or three-way valves with two tubes being acted upon, one of which is normally-open and one of which is normally closed (NO/NC). Likewise, two different tubes may be arranged to thread through the valve so that actuation of the valve "pinches" one tube at the same time it "unpinches" the other, resulting in a two-way (bi-acting) valve. As a matter of economy and convenience, all valve bodies are preferably provided as universal two-way valves with the specific valve action (NO, NC or NO\NC) being determined by the manner of threading of the tubing through the valves during AFDS assembly. Likewise, the pinch valve design allows the economy and convenience of using the same valve design for both air lines and liquid lines, including both in a single two-way valve. The tubing is commercially available medical/dental grade plastic tubes, and they can be changed-out easily since they are simply threaded through the valves rather than multiple measure-cut-and-connect segments. Although the pinch valves can be adapted to be operated by mechanical or electrical/mechanicalmeans, pneumatic actuation of the valves is preferred for dental application of the AFDS since dental clinics have a regulated compressed air supply. It is an important feature of the AFDS that the same grade and type of tubing may be used both as the valve actuator tubing, and as the "pinched" supply tubing within the valve. This allows a system of valves to be interconnected, with structural simplicity, in which the pinchable tubing threaded through one valve becomes the actuator tube for another valve. In general, the term "air signal" will be used herein to distinguish a tube providing pneumatic actuation for another valve in the AFDS, as distinguished from a tube carrying water, solution, drying air, bottle pressurization air, or the incoming regulated compressed air supply from the dental unit.
A unique feature of the AFDS is supported by the interconnectivity by which pinch valves pneumatically control the action of other valves by means of "air signals", as well as controlling the flow of fluids. This interconnected system of pneumatically actuated valves of the AFDS forms a network which performs what are, in essence, logic functions. The pneumatic pinch valves are located in each of the three different modules of the AFDS, but function in combination by means of the interconnecting tubes. The outputs from the valve network in turn actuate conventional slave valve functions which carry out fluid control and lockout functions.
By use of pinch type valving, special tube routing, and constant air pressure in the headspace of the water bottle, the system of this invention eliminates the serious problem of backflow (suck-back) of contaminated water or treatment solution. In the current best mode embodiment, conventional solenoid actuated valves are also used in the air-only portions of the primary pneumatic controls to interface with the electronic controller, but not in any location where water or disinfectant solution is present.
The current best mode method of the invention comprises steps in one or more mode cycles including a PM (evening) cycle and an AM (daytime) cycle which may be employed separately or sequentially. The PM cycle steps include: 1) Flushing the lines with one or more disinfectant solutions for one or more timed periods or volumes; 2) Flushing with one or more flush liquids including fresh, preferably sterile, water for a timed period or volume or optionally with an alcohol solution; and 3) optionally (preferably) purging or evacuating the lines with a compressed gas, preferably air, or by vacuum suction, either continuously or at least until the lines are substantially dry. The AM cycle includes the steps of flushing with disinfectant, followed by rinsing with water. When alcohol is used in the disinfected solution it should be ethanol and the lines preferably should be air purged before step 1 to prevent dilution of the alcohol.
Note that in both the AM and PM modes, or in any alternative sequence of disinfection, the outlet water lines coming from the dental unit to dental instruments will be placed in an appropriate drain container or discharge fixture to receive expended solutions and rinse fluids. Ordinarily the handpieces, instruments and accessories of the dental unit will first be removed, and disinfected separately in a manner recommended by the manufacturer.
A feature of the control system of the preferred embodiment is that the use of the dental unit for patient treatment is locked out, i.e., the dentist cannot use the dental unit, once either the AM or PM sequence of the AFDS is initiated, and remains locked out until the dental unit water supply is safe for use. This aspect of the method includes a positive safety lock-out mode which prevents interruption of the operation of the AFDS for biofilm control at steps wherein it would be undesirable to use the dental unit immediately following such step, and/or to prevent the use of the dental unit while the flush procedure is in progress, and/or to prevent disinfectant solution from reaching the patient. The method further preferably includes requiring the AM cycle to be completed at the beginning of a use period, e.g., in the morning, so as to prepare the system for use, even after a prior day's disinfecting procedure, i.e. after the PM cycle had been done the evening before. Optional additional steps include pre-purging with air or gas (e.g., N2, ethylene oxide), repeat flushing of the lines with the disinfectant solution, or repeat flush with water and/or other rinse media.
Anti-microbial flush systems of this invention can be employed with sealers and polishers, as well as with dental units. Examples of units to which this invention system apparatus can be connected include: Bobcat™ Ultrasonic sealer; CavetronrM Jet 30 combination Cavetron unit and jet air (air/water/abrasive) polisher, Prophy-JetM 30 polisher, and CavitronrM 3000 Cavitron unit, all from Dentsply Co. of York, PA; and Autoscaler of Southeast Instruments of Miami, FL. The interconnection of the AFDS of this invention to such sealers and air polishing is accomplished by use of a standard quick-disconnect off a Tee to the single line from the AFDS to the Dental Unit, and then connecting a line from the fitting to an air switch adapter (ASA-2), and electrically connecting the air switch adapter to the foot pedal input of the scaler/polisherunit. Once the scaler/polisherunit is connected to power, when the AFDS selector valve is set to either AM or PM it will activate the sealer/polisher unit and automatically flush that unit's lines as well as the DU handpiece console.
Thus, with such an air/electric switch, air-valve or solenoid, any water system can be controlled and flushed automatically by the AFDS of this invention. Indeed, the system of this invention is easily adapted to multi-chair, multi-dental unit operation by using simple parallel manifolding. The individual dental units can be individually activated for the flush cycle by appropriate selector valves.
A programmable electronic controller is used to control all functions the AFDS of this invention including the indicators, battery backup, the purge, flush and rinse run time, and in- tubing disinfectant solution dwell time. The timing function is incorporated as an integral part of the controller, or optionally it may be a discrete timer unit. In the current best mode embodiment, the controller uses a versatile micro-controller integrated circuit which can be adapted to a wide range of timing and sequencing options. This timer permits the user, e.g., dental professional, to preset cleaning times so there are regular daily flush cycles. The PM cycle can be pre-programmed (preset) to start after close of business in the evening, and the AM cycle to start before start of business in the morning. Optionally, a midday (lunch hour) repeat of the AM cycle can be programmed. The AFDS preferably includes a battery backup and optionally a conventional gel-cell type trickle charger to supply system operating power during power outages. The bottle assembly of the AFDS can optionally incorporate fluid level sensors, meters or warning lights. The bottle assembly can also incorporate overpressure relief features, such as those disclosed in my copending application S/N 08/795,218 filed February 5, 1997 for SELF- REGULATING FLUID DISPENSING CAP WITH SAFETY PRESSURE RELIEF VALVE FOR DENTAL/MEDICAL UNIT FLUID BOTTLES, the disclosure of which is hereby incorporated by reference.
Any of a number of disinfectant, antimicrobial, or sterilizing fluids may be used as the disinfectant solution. A solution currently accepted for DUWL treatment is a 10% solution of commercially available bleach, which typically contains 5.5% sodium hypochlorite solution; thus an appropriate concentration of sodium hypochlorite is approximately 0.05%. The system of the invention can also employ 2.4% glutaraldehyde (e.g. Maxicide brand); a soap solution including 1% chlorhexidine gluconate (e.g. Hibiclens); as 0.12% chlorhexidene gluconate in 12% ethyl alcohol (e.g., Bio-2000 made by Mycrilium Laboratories, Phoenix, AZ).
Other treatment solutions include ethyl alcohol, peroxide, ozone, betadyne and the like, aqueous disinfectant solutions, zinc-containing microbial lipid antagonists, or a combination thereof. In-line irradiation may also be employed. One of ordinary skill in the art can adapt the delivery timing and sequencing of the AFDS to optimally employ such solutions, with or without air purge.
Furthermore, in addition to medical grade, sterile or distilled water, the patient use fluid dispensed by the AFDS may be a commercially available surgical antiseptic irrigation solution. Fluid flow, water volume or biosensors can be employed in conjunction with the AFDS or the bottle control unit so at the bactericide, antimicrobial flush agent or disinfectant can be metered by volume, or the microbial content drop can be assessed as a function of flushing, or a combination of both, and the disinfecting step(s) of the cycle terminated upon a preset volume flow or reaching a preset low bacterial/microbial content threshold. Conversely, in-line biosensors can be employed to assay microbial content, and once a predetermined contamination level is reached, an audio or visual alarm is triggered, the unit is locked out and the lines automatically flushed in the AM and/or PM mode cycles. Alternately, the entire unit becomes locked out once the in-line biosensor detects unsafe levels of microbial contamination, and the dental unit's waterlines must be changed out. An exemplary biosensor is a Cepheid in-line microbial DNA assayer (Cepheid, Santa Clara, CA). Alternately, the water can be assayed from time to time by taking samples from the delivery end of the lines, and appropriate action of continued use, AFDS flush or change out can be taken.
In addition to its principal application to dental units, the invention is suitable for many uses where hygienic maintenance of water lines is important. The system may be adapted for use in cases where bacterial or microbial contamination is an interference or hazard. Examples include, but are not limited to: Drinking water lines in school or public fountains; refrigerators; coffee makers; dishwashers, humidifiers, faucet aerators, water refill stations; RV or camper vehicle or remote site and other potable water lines; food and soft or mixed drink preparation water lines; barber, hair salon and cosmetology stations; air cooling mist systems; toilets, and other treatments or uses.
BRIEF DESCRIPTION OF DRAWINGS:
The invention is illustrated in more detail in the drawings and figures in which: Fig 1 is an isometric schematic view of a dental chair and related apparatus showing a typical installation of the single line Antimicrobial Fluid Delivery System of this invention; Fig.2 is a schematic drawing showing the interconnection of a prior art dental unit with the AFDS of the invention.
Fig. 3 is a flow chart depicting the preferred AM and PM treatment cycles using the single line AFDS controller of the present invention; Figs. 4A-H are a series of figures which depict schematically the pneumatic valve and tubing circuitry in AFDS electronic CM in the operating states corresponding to the PM and AM steps in Fig.3;
Figs 5A-I are a series of figures which depict schematically the pneumatic valve and tubing circuitry of the AFDS Bottle Assembly Module in the same sequence of operating states corresponding to the PM and AM steps in Figs.3 and 4 A-H;
Figs 6A-C are a series of figures which depict schematically the pneumatic valve and tubing circuitry of the AFDS Unit Module in the same sequence of operating states corresponding to the PM and AM steps in Figs.3 and 4A-H;
Figure 7 is a simplified circuit diagram depicting a first embodiment of the electronic controller of the AFDS employing an integrated circuit micro-controller (programmable microprocessor) and single chip solenoid driver;
Figure 8 is a circuit diagram depicting an alternative embodiment of the electronic controller of the AFDS employing discrete solid state electronic components and MOSFET solenoid drivers; and Figure 9 is an exploded isometric of the universal bi-directional pinch valve assembly employed in all three modules, CM, BA and UM of this invention.
DETAILED DESCRIPTION OF THE BEST MODE:
The following detailed description illustrates the invention by way of example, not by way of limitation of the principles of the invention. This description will clearly enable one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what I presently believe is the best mode of carrying out the invention.
In this regard, the invention is illustrated in the several figures, and is of sufficient complexity that the many parts, interrelationships, and sub-combinations thereof simply cannot be clearly or meaningfully illustrated in a single patent-type drawing. Accordingly, several of the drawings show in schematic, or omit, parts that are not essential in that drawing to a description of a particular feature, aspect or principle of the invention being disclosed. Thus, the best mode embodiment of one feature may be shown in one drawing, and the best mode of another feature will be called out in another drawing. A dental delivery system is illustrated schematically in Fig. 1, which includes a standard dental chair 9 and its conventional dental unit 2 (handpiece console), for providing and controlling feed of air, light, water, and, optionally, low voltage electricity for a variety of cleaning, drilling, oral surgery, orthodontry, abrasive cleaning, etc. The illustrative dental unit 2 generally has a syringe 3 and at least one drill, handpiece or other dental instrument 4 (three are shown in the example of Fig. 1), although this arrangement is not strictly required. A foot control 5 is conventionally provided whereby the dentist may control operation of the instrument 4 (as well as, perhaps, other functions).
Each of the delivery hoses 6a-6c connect each of the instruments 4 to the dental unit 2, and a syringe hose 6d connects the syringe 3 to the dental unit 2. The delivery hoses 6a-6c and the syringe hose 6d will generally differ in construction from each other, and such hoses may also vary somewhat in construction from application to application. These hoses generally deliver both water and air to the instruments 4 and the syringe 3, as well as electrical power to handpiece connectors having high intensity bulbs therein for illumination, such as shown in U.S. Patent 5,476,379. The syringe hose may also include a drain line. Standard saliva ejector 6e and HVE 6f are also suction (drain) lines. Drink cup water is supplied through line and spigot 6g. However, since the portions of these hoses 6a-6g which deliver air, vacuum and/or electrical power are not discussed in detail herein, further references to these will be to the "hoses 6," and references to "flushing" or "running solution through" the hoses 6 will refer to those portions thereof which normally deliver water (as opposed to air, vacuum or electrical power). The bowl is 6H. The components of the dental unit which supply and control water within the dental unit through lines, valves, hoses and the like are indicated collectively as the dental unit water line system ("DUWL") 25.
A conventional junction box 7 provides a terminal point for which air, drain, vacuum and electrical supply lines, and the like (can be connected to the dental unit 2. These lines are shown schematically in Fig. 1 by dashed lines, identified, respectively, as: Electrical, Air, Vacuum and Gravity Drain. A public water supply is not shown since it is not recommended with the AFDS, although it is a conventional component of a prior art dental unit. An interconnection umbilical sleeve 8 is provided for housing the various air, electrical, water, drain and vacuum supply lines from the junction box 7 to the console 11 and thence to the dental unit 2. The AFDS controller 10 water and solution reservoir control unit ("Bottle Assembly") 20, and unit interface module ("Unit Module") 30, are, combined, an example of the best presently known embodiment of the anti-microbial slime and biofilm control system of this invention. They are shown secured to the dental unit console, but may be attached to any convenient place, e.g., the wall adjacent the chair.
Figure 2 is a schematic isometric drawing showing the interconnection of the three modules of the current best mode embodiment of the AFDS 1 of the present invention, and its interface lines to a prior art dental unit). The AFDS control module 10 is identified on the upper right. The bottle assembly 20 is shown at the top with the water bottle 21 and the solution bottle 22 attached. The unit module 30, which interfaces with the prior art dental unit 2 (see Fig. 1), is shown at center left. The control module 10 is connected to the bottle assembly 20 by a pneumatic tube bundle or umbilicus 27. The bottle assembly 20 is in turn connected to the unit module 30 by pneumatic and fluid outflow umbilicus 26.
Interface lines (tubes) are shown schematically extending from the unit module 30 to interface with the prior art dental unit as follows: From the J-Box 7 (Fig. 1) high pressure air passes through the DU master switch "M" via Line 361 to the UM where it is regulated to 35-40 psi. Line connector pair 280, 281 connect in series to the dental unit coolant valve signal line, and can open the dental unit water system valves during AFDS disinfectant/rinse cycles to permit flow of fluid through the dental unit. Line connector pair 284, 285 connect with the dental unit syringe valve and likewise open this valve to permit fluids to drain through this portion of the dental unit water system during disinfection rinse by the AFDS. Line connector pair 282, 283 are connected in line to the dental unit foot control unit which provides operator control of pneumatically powered dental instruments, such as high speed drills 6a-d in the handpiece selector block 12. During AFDS disinfection/rinse or PM hold cycles, the AFDS interrupts flow through the foot control line and locks out dental unit pneumatic instruments. Line connector 359 is the AFDS single fluid delivery line which delivers water, solution and purge/drying air to the dental unit water delivery system. The electrical power to the AFDS is supplied by cord 501 connected to the AFDS control module 10 which connects to 12 volt AC via step-down from 120v or 240v building power. The AFDS can be adapted if desired to various other electrical sources by suitable converters, such as storage batteries, vehicle batteries, conventional UPS units, etc. The construction and operation of the inventive AFDS will be evident to one skilled in the art by study of Figs. 3-6. Fig. 3 is a flow chart of the AFDS operation as a dual mode system, with optional air/gas purges. It is keyed to the Figs. 4-6 valve and tubing circuit series and the Tables 1-6 below showing the status of the valves and solenoids of the three modules. Thus, Figs. 4A-H show the CM, Figs. 5A-I the BA and Figs. 6A-C the UM. For example, when the AFDS is "OFF" as shown in step 325 in Fig. 3, the CM valve solenoid circuit is shown in Fig. 4A the BA is in Fig. 5A, and the UM is in Fig. 6A. Table I summarizes the valve/solenoid status for the AFDS CM corresponding to Figs. 4A-F for the PM cycle; Table II the status for BA corresponding to Figs.5A-F for PM; Table III the UM corresponding to Figs. 6A-C for the PM cycle; Table IV the CM for the AM cycle, Figs. 4G, H; Table V the BA for the AM cycle, Figs. 5G-I; and Table VI the UM for the AM cycle, Figs. 6A-C. In the tables, the valve states are: C = Closed, O = Open and O/C = momentarily open, then closed.
Fig. 3 is a flow chart depicting a general method 310 of flushing the lines and using the apparatus of the invention, including the two presently preferred treatment cycles. The method 310 is controlled by the AFDS including the control module 10 with supply of medical grade rinse water from bottle 21 and solution from bottle 22 from the bottle assembly 20, supplied to the dental unit through unit module 30, as seen in Figs. 1 and 2A. In the following description of the method, references to dental unit components, switches, control and displays refer to Fig. 1 and 2.
According to the inventive method 310, the dental unit 2 will normally be in an operational state 311. Prior to AFDS method operation, the dental unit delivery hoses 6 are removed from the hangers. Normally, the instruments or handpieces have been removed from the delivery hoses. If not, they should be removed and the handpieces themselves separately sterilized by the procedures recommended by the handpiece manufacturers as the AFDS .does not treat or sterilize. The delivery hoses 6 are placed in the appropriate receiving receptacle or drain fixture and the dental unit coolant valves are opened to permit the treatment solution to discharge from the ends of the hose into the receiving receptacle. As can be seen in Fig. 3, the method 310 is logically divided into two series of operational steps: an AM cycle 323, and a PM cycle 324. The AM mode can be used any time during the day, and prepares the dental unit for immediate use. The AM mode cycle 323, shown on the left, is initiated by the Dental Unit operator turning on the office equipment and readiness for the day's use. When the user activates the Master Valve 437 to turn on the AFDS, the foot control lockout valve (292 in Fig. 6) automatically closes, preventing use of the dental unit 2. This is shown as "Turn On" step 312 for the AM cycle 323, and illuminates master indicator (LED) (843 in Fig.4). Then in step 326 the user selects the "AM" process by toggling the selector valve 440 to the A.M. position. Upon depressing the Actuator valve 435 to "on", step 313 is instituted and the cycle proceeds automatically in sequence as follows: To "flush the DUWL water lines with solution" step 314, wherein the dental unit water lines 25 (provided as part of this invention) are treated, and the solution LED 845 is illuminated. Then automatically "flush the DUWL water lines with water" step 315. This is followed by step 327 in which cycle complete LED 844 is lit, and a piezoelectric audio alarm mounted internally within the control unit sounds. The system then enters a "wait for operator intervention" hold step 316, which enables the dental unit (DU) to be operated by the dental professional after turning off the AFDS by toggling the master switch 437 to "off. Thereafter, the dental unit 2 is enabled such that it may again be operated as indicated by reinstatement of the "dental unit ready for operation" status 311. The dental unit delivery hoses and syringe are then returned to their hangers, the dental unit coolant valve is reset and the syringe button depressor is unlocked.
The PM mode cycle 324 is depicted on the right side of Fig. 3. The PM mode prepares the dental unit for extended periods of non-use. After AFDS "Turn On" 317 (identical to step 312), the user switches Selector 440 to "PM" in step 328. The user then activates switch 435 to "on" and the controller 10 begins the "initiate PM" step 318. The PM cycle 324 proceeds automatically, treating the system with solution" step 319, and LED 845 will illuminate wherein the DUWL 25 is treated; then to a "flush system with water" step 320, wherein the DUWL 25 is flushed with water; then to a "purge line system with air" step 321, wherein the DUWL 25 is purged with air for a sufficient time to be substantially dry, and optionally air purge LED 846 is lit. Optionally, this step may be omitted, especially if the "optional purge air" step 330 has been performed, as described below. The AFDS then enters a "wait for operator intervention" hold step 322, wherein the AFDS retains the dental unit lockout and LED 847 is illuminated until the operator initiates step 326 of the AM process. When the "initiate AM" cycle 326 is initiated, the method 310 proceeds as previously related above until the completion of the AM cycle, ending at step 311, ready for dental unit operation. The PM mode is typically at the end of the day when there are no more patients. This can also be done prior to a weekend or vacation period. Then at the start of the next business day, the AM mode needs to activated and the unit will cycle through the AM mode so that there is a treatment before the first patient of the day.
In both the AM mode and the PM mode, an alternative additional air purge step may be added prior to the solution phase to empty the DUWL prior to treatment. This is shown as an "optional purge air" step: 331 between steps 326 and 313 on the AM cycle and 330 between steps 318 and 319 on the AM cycle.
Note that the lockout initiated in steps 312 and 317 prevents the operator from using the
Dental Unit before the treatment cycle is completed. This is an important safety feature of the best mode of the invention. Even if the main air experiences a failure or is depleted, or if the
AFDS controller unit is turned off, or the master control unit on the Dental Unit is turned off, the AFDS unit will remain in the bottle lockout mode until released into the AM mode.
As seen in Fig. 2, optionally and preferably there are LED indicators to show in what stage (process functional step) the control unit is operating. That is, the indicators note with a light that the Master is in the ON position, an indicator light goes on when the system is in
Lockout, a light goes on when the solution is being cycled through, when the air purge is in operation, and when the cycle is complete.
Figures.4 A to 4H, 5A to 51 and 6A to 6C show schematic circuit layouts of the valves and tubing of both the controller 10, the bottle assembly 20, and the unit module 30, respectively as well as the interface connections between the modules, to the prior art dental unit and to the electronic controller located within the control module. Each subfigure is part of a sequential series which corresponds to different operational states of the AFDS as shown in Tables 1 through 6 below and which correspond to the method steps described in Fig.3.
Figure imgf000022_0001
Figure imgf000023_0001
Figure imgf000023_0002
Figure imgf000023_0003
Figure imgf000023_0004
Figure imgf000024_0001
Figure imgf000024_0002
Figure imgf000024_0003
Because of the complexity of the functional relationship between the modules and their components, a functional description of a number of types of components which are used in a number of different locations within the AFDS will be useful, prior to discussing the detailed interrelationships as depicted in Figs. 4-6. The following notes describe aspects on comparable or interchangeable components common to most or all of these figures:
Lines (tubing): Lines passing between modules are preferably contained within an umbilicus or bundle and preferably have a connector junction where the line passes through each module case. The term "connector" with respect to a tube which passes between two modules refers to the functional connection between the modules with respect to the tube and is represented in each figure by a round labelled dot at the terminus of the line.
In the preferred embodiment, the "connector" will also represent a pair of bayonet type interface connectors or the equivalent which optionally are mounted on and penetrate the outside surface of each module and connect to such line inside and outside. The designation of such a line is the same part number within each such module and within the umbilicus. Thus a tube joining two modules is referred to as if it were a continuous tube even though it may, for manufacturing and assembly convenience, be interrupted by a pair of module interface connectors.
In general the branching of tubes within modules is indicated by a "T" or "Y" junction symbol at the intersection of lines. This should be understood to represent a suitable tubing connector know in the art. Similarly, where a tube connects to a component, such as a pneumatic actuator connection to a pinch valve, or a mechanical or solenoid valve input or output, a solid rectangle at the junction represents a conventional tubing connector known in the art. For visual clarity, where a four-way tubing junction is depicted, a rectangle of "gussets" at the junction distinguishes this case from an over-under tube crossing without junction.
Component types: Certain types of components are denoted by both a part number label and an abbreviation label referring to a series of comparable parts, such as PV12, PV14 etc. for pinch valves, ASW-1, ASW-2 etc. for air switches. These supplementary labels are for convenience in interpretation of the description and figures due to the large number of components being described. Additional abbreviations are FC for flow control valve, EP for electrical plug, SND for solenoid, R for pressure regulator, and TV for toggle air valve. In the best mode AFDS a number of such components of the same type may be made interchangeable for economy of manufacture, and a general description of the component type is applicable to each such component.
1. The pinch type valves "PV" are of the type shown in Figure 10. In Figures 4, 5, and 6, the pinch valves are shown with labelled n/o and n/c ends, referring to the normally open or normally closed status of the line passing through the pins nearest that end. The actuating (pilot) air connection is shown by a line joining at one end of the valve. Input and outputs from pinch valves are distinguished by the flow arrows and description of the lines passing through the valve body, and the actual state of a pinch valve line is depicted by whether the pair of pins bearing on the line touch each other (closed) or do not touch (open). These valves are used in the best mode AFDS in two state operation, (fully closed or fully open) although the valve design permits adaptation to a partial open mode of operation based on the balance of spring force, actuator pressure and line pressure. The water bottle manifold valve WC-1 and solution bottle manifold valve SC-1 operate by the same principal, and in addition the manifolds have an input connection for bottle pressurisation air.
2. The input and output ports on pressure regulators are shown as IN and OUT respectively on each regulator "R-l, R-2, and Reg-UM". These are mechanically adjustable air pressure regulators known in the art.
3. The toggle type mechanical air valves "TV" located in the AFDS controller are conventional valves known in the art, and are of two types: Those with one input and two outputs are two way valves with selectable output path. Those with a single output have an internal exhaust that vents the output line in the closed position.
4. The solenoid valves "SND" located in the AFDS controller are conventional valves known in the art, and are of two types: Those with labelled three way are normally closed with an internal vent of the output line when closed. Those with labelled two way are normally closed without venting of the input line when closed. The solenoid valves are each connected to drivers in the electronic controller "PC BOARD" by conventional plug connectors. Each solenoid plug connects with a corresponding plug in the electronic controller board: EP1 to J4; EP2 to J5; and EP3 to J6. (See Figs 4 and 7).
5. The flow control valves labelled "FC" are screw adjustable single line pinch valves known in the art, which provide an adjustable flow resistance. Where one end of such a valve is shown to exhaust, it functions as an adjustable slow air pressure bleed to allow upstream components to depressurize when the air supply to such components is closed.
6. The air switches ASW-1, 2, 3 and 4 in the AFDS controller provide (together with the solenoid valves) the communication between the electronic portion of the AFDS (labelled PC Board in Figure 4) and the pneumatic system. Each comprises a conventional push button type normally-open electrical TAC switch in conjunction with an expanding tube pneumatic actuator, arranged so that pressurisation to the actuator closes the electrical contacts (On) and depressurization opens the switch (Off).
7. The components labelled 1-1 through 1-6 are conventional light emitting diodes LED which function as indicator lights of particular AFDS conditions or status. These may optionally be supplemented by piezo-electric alarms or auditory signals. Figures 4A, 5A and 6A show the AFDS control module, bottle assembly and unit module respectively in the "AFDS off state. This corresponds to steps 325 and 311 as shown in the method flowchart, Figure 3. This also corresponds to column A labelled "off in Tables 1 through 6 above. The AFDS is designed to provide water to the dental unit for normal therapeutic use when the AFDS is unpowered, provided compressed air is available from the dental unit air compressor (preferably at about 60 psi) and the AFDS water bottle sufficiently filled.
The dental unit air pressure is supplied to air inlet 364, which is a junction connected to the dental unit compressed air supply line to divert compressed air to the AFDS as needed. Inlet air line 365 leads from air inlet 361 to the unit module 30. Within the unit module 30, the inlet air line 365, with one branch going to the input 288 of the unit module regulator, (REG UM) 286 where it is reduced to preferably about 35-40 psi and exits output 287 and into unit module bottle air line 375. The air passes through connector 358 of the unit module 30 to the bottle assembly 20 continuing through line 375, through bottle air routing valve (PV30) 353. PV30 353 is normally open, and thus the compressed air ("air") continues in water pressurising line 376, which connects to input port 397 (B) of the water bottle manifold 350. This allows the regulated air pressure to charge or pressurise the water bottle 21 to a pressure of 35-40 psi. from the dental unit while the AFDS control 10 is turned off.
The other branch of air inlet line 365 bypasses the unit module regulator, (REG UM) 286 and leads out from the unit module 30 through connector 361, passing through the bottle assembly 20, and continues by connector 414 to the AFDS control module 10. Within the control module line 365 leads to input port 443 of control module inlet regulator (R-2) 428 where the air pressure is reduced to preferably about 50 psi. The air then travels from the output port 444 of regulator 428 to the input port 461 of the master on/off valve (TV3) 437. Since the AFDS is off, Valve 437 is closed, and no further pressurisation of the AFDS control module occurs in this state. For this reason, all the pneumatically actuated valves of the AFDS are in their normal state.
Since, as was described above, the water bottle is pressurized with the AFDS in its "off state, and since the water bottle manifold valve (WC-1) 394 in the water manifold 350 is in its normally open state, water is force by air pressure through water outlet line 380 and flows through WC-1 394. The water flow continues along line 380 through the normally open side of air purge valve (PV31) 351 and normally open side of water routing valve (PV32) 352 and continues to a T junction with AFDS fluid outlet line 381. The other junctions within the AFDS to line 381 are solution outlet line 377, which is closed by the solution manifold valve 393 in its normally closed state, and line air purge line 372, which is closed by the normally closed side of air purge valve (PV31) 351. Thus the water from the water bottle is the only fluid entering line 381 in the AFDS off state. The fluid flows out through AFDS fluid outlet connector 359 to the dental unit water delivery system. The dental unit, of course, has internal valving controlling water flow to its various instruments and accessories, and the AFDS thus supplies water on demand to the dental unit. In the AFDS off state, not only is the solution manifold valve 393 closed, but the solution bottle has no pressure charge as a safety precaution, since solution pressure line 368 passes through the normally closed end of bottle air routing valve (PV30) 353.
Figures 4B, 5B and 6B show the AFDS control module, bottle assembly and unit module respectively in the "AFDS on" state, in which the master on/off valve (TV2) 437 in control module 10 has been toggled to the "on" position This corresponds to steps 317 or 312 (of the AM or PM cycles respectively) as shown in the method flowchart, Figure 3. This also corresponds to column B labelled "on/not active" in Tables 1 through 6 above.
As described above with respect to the AFDS "off state:, the other branch of air inlet line 365 is passed through regulator 428 in the control module and, after pressure reduction, connects to the inlet port of the master on/off valve 437. When valve 437 is turned on the air pressure passes through the valve and out the output port 460 into master control line 367 providing air pressure to the input port 462 of selector valve 440. Line 367 also communicates through the normally open side of the PM lockout valve 434, to the input port 457 of the actuator valve (TVl) 435, to the master air switch 429 which illuminates indicator 843.
The air pressure also then communicates to the input ports 450, 451, and 453 of solenoids 421, 422, and 423, to the normally closed side of PM lockout enable valve 419, to the input port 445 of control module bottle air regulator (R-l) 427, through regulator 427 where the pressure is reduced to preferably about 35-40 psi and exits through the output port 446 into control module bottle air line 369. The regulated air passes through line 369 via connector 412 to the bottle assembly 20 and then to the B port 400 of the solution bottle manifold 354 and charges and pressurises the solution bottle 22. Line 369 also passed to the closed end of bottle air routing valve (PV30) 353. Solution manifold valve 393 in the solution manifold 354 is in its closed position. Air pressure also communicates from master control line 367 through connector 410 to the bottle assembly 20, and there passes to actuator port 405 of bottle air routing valve (PV30) 353, valve 353 shift state, closing unit module bottle air line 375. thus discontinuing pressure from the unit module to the bottle assembly (the delivery pressure in the "off AFDS state). This same state change of valve 353, opens solution pressure line 368 (on the normally closed end of the valve, allowing the regulated air from the AFDS control module 10, into line 376 to charge the water bottle manifold 350 and pressurises water bottle 21 from this new source. Thus the water bottle remains constantly pressurised, either from the unit module regulator 286 or from the control module bottle regulator 427.
Air pressure from master control line 367 also passes to actuator port 404 of water routing valve 352 which in turn also shifts state, closing off the non metered water line 378, and opening the metered water line 379 which passes through the water metering adjustable flow control 355. Both lines 378 and 379 are connected to AFDS fluid outlet line 381, which is the liquid line which connects the AFDS system to the dental unit water supply line. This change from non-metered to metered flow allows the water flow rate to be adjusted (preferably by factory calibration) for the AFDS rinse cycle(s).
Air pressure from master control line 367 also communicates through connector 357 to the unit module 30 to connect to the actuator port 289 of coolant signal valve 291 and to the actuator port 290 of foot control lockout valve 292, causing each valve to change state. Valve 291 will shift closing offline 371 which is the dental unit water coolant signal line, and opens line 373 which lets the AFDS system control the dental unit water valve. The dental unit water valve (13, Fig. 2) opens in response to this "air signal", allowing fluids delivered by the AFDS to flow through the dental unit water lines to perform the disinfect, rinse and optionally air purge steps. Valve 292 also shifts closing off the air pressure line 300 from the dental unit foot control preventing use of the dental unit handpieces while the AFDS system is on. Figures 4C, 5C and 6C show the AFDS control module, bottle assembly and unit module respectively in the state in which the AFDS master valve 437 is "on", the PM mode selector valve 440 is set to PM, and the actuator valve 435 is turned "on" (the actuator valve is spring loaded, and is only depressed momentarily to cause a pulse air signal). This corresponds to steps 318 and 319 of the PM cycle as shown in the method flowchart, Figure 3. This also corresponds to column C of the PM mode labelled "1-3 Min." in Tables 1 through 3 above.
When the selector valve 440 is set to its PM position, the air pressure entering selector valve 440 at port 462 exits through the PM output port 472 and pressurises PM mode line 471. The pressure in line 471 travels to the actuator port 464 of control valve (PV20) 441 causing it to close off cycle actuator line 470. Closing off line 470 in turn prevents an air signal from output port 458 on actuator valve 435 from reaching the actuator port 448 on the lockout release valve (PV12) 418. The pressure in line 471 also passes to and actuates airswitch 431 which enables the PM mode in the electronic controller board 433. The pressure in line 471 likewise passes to actuator port 459 on the backflow valve (PV22) 436 causing it to close preventing the air pressure in master control line 367 from backflowing into AM mode line 473.
When actuator valve 435 is momentarily actuated, air pressure passes into cycle actuator line 470, but goes only to air switch 430 to trigger the pc board 433, since line 470 is closed off at control valve (PV20) 441. Circuit board 433 controls timing and activation of solenoids 421, 422, and 423. The circuit board also controls the illumination and timing of indicators 843, 844, 845, 846, 847, and 848.
The timing sequences preset by the factory are, for example, 3 minutes for the solution, 4 minutes for the water rinse and 10 minutes for the air purge, although other sequences are feasible, and the microprocessor IC 710 by its nature is easily reprogrammable. Solenoid 421 opens for a period of 3 minutes. From solenoid 421 the air pressure signal passes through connector 413, through solution signal line 374 to the actuation port 399 of solution manifold valve 393, opening the valve and releasing the solution. Simultaneously valve 394 in the water manifold is closed stopping any water from entering the lines, or a backflow of solution from entering the water bottle. Also air pressure to the water bottle is equal to that of the solution bottle at all times. This also prevents a backflow. The solution now being released through line 377, passes through variable flow control 356, which releases a metered amount of solution into line 381 which is connected to the main water line 25 of the dental unit.
Solenoid 422 sends an air signal through connector 411 of the control 10, through interconnect line 373 to the unit module 30, through connector 360 on the unit module 30, through the now open side of the water coolant routing valve 291, through connector 281 to the existing dental unit water coolant valve, Fig. 2, 13, causing it to open allowing fluids to pass through the normal dental unit water passages and exit through the dental unit handpiece hoses into a receptacle. It also activates interconnecting line 383, which is connected to the pilot 293 of the syringe drain valve 294, and causes the normally closed syringe drain valve 294 in the unit module 30 to open allowing the fluids to circulate trough the Y fitting located inside the syringe handle located on the dental unit. The fluids enter the unit module 30 through connector 284 passing through valve 294 exiting through connector 285, which is connected to a drain or vacuum system. Figures 4D, 5D and 6C show the AFDS control module, bottle assembly and unit module respectively in the state in which the AFDS continues to the water rinse following step 319. This corresponds to step 320 of the PM cycle as shown in the method flowchart, Figure 3. This also corresponds to column D labelled "4-7 Min." in Tables 1 and 2, and to column C in Table 3 above. At the end of 3 minutes, solenoid 421 will close and exhaust the air pressure in line 374 causing solution manifold valve 393 to close, and water manifold valve 394 to open. This causes the AFDS to deliver rinse water to the DUWL.
Figures 4E, 5E and 6C show the AFDS control module, bottle assembly and unit module respectively in the state in which the AFDS continues to the air purge following step 320. This corresponds to step 321 of the PM cycle as shown in the method flowchart, Figure 3. This also corresponds to column E labelled "7:10 -10:10 Min." in Tables 1 and 2, and to column C in Table 3 above. At the end of 7 minutes and 10 seconds, two way solenoid 423 will open for 10 minutes, also 3 way solenoid 442 will reactivate along with solenoid 423 for 10 minutes and pressurising line 372, which opens the lockout enable valve 419 through port 447, this allows air pressure from line 367 to pass through the lockout enable valve 419, pressurising line 368, to the pilot port 456 of the PM lockout valve 434, closing off line 367 to the input port 457 of the actuator valve 435, through connector 417, through line 368, to the port 403 of routing valve 351, which allows purge air from line 372 to enter line 381 to the dental unit, to indicator 846 and driving the water out of the dental unit water lines leaving them to air dry.
Figures 4F, 5F and 6B show the AFDS control module, bottle assembly and unit module respectively in the state in which the AFDS continues to "waiting for operator intervention" following step 321. This corresponds to step 322 of the PM cycle as shown in the method flowchart, Figure 3. This also corresponds to column F labelled "end cycle" in Tables 1 and 2, and to column B in Table 3 above. At the end of 10 minutes solenoid 423 will close, and in turn this closes the lockout enable valve 419. Indicator 845 remains illuminated. Line 368 remains pressurised locking the water and solution out of the system, the AFDS is now waiting for operator intervention. The next step is to initiate the AM mode.
Figures 4G, 5G and 6C show the AFDS control module, bottle assembly and unit module respectively in the state in which the AFDS operator selects the AM cycle following step 322 of the PM cycle. This corresponds to step 326, 313 and 314 of the AM cycle as shown in the method flowchart, Figure 3. This also corresponds to column G labelled "1-3 min" in Tables 4 and 5, and to column C in Table 6 above.
Note in Figure 3 that when the AM cycle is entered from the PM cycle, the AFDS is already turned on. The only way to depressurize line 368, which in turn releases the PM lockout valve 434 in the control 10 and routing valve 351 in the bottle assembly 20 and brings the water and solution back on line is to set the selector 440 to the AM position to begin the AM cycle.
Air pressure passes through the selector valve 440 to the AM output 463 through line 473 to air switch 432 and through flow control 438 through the normally open side of backflow valve 436, to the input port 457 of the actuator valve 435. When valve 435 is momentarily actuated, an air signal passes through the valve, through the normally open side of control valve 441, to the pilot of lockout release valve 418, which opens momentarily to release any pressure in line 468 cancelling the lockout. It also activates switch 430 which enables the circuit board 433 to perform the timing and sequencing functions for the AM mode. The timing sequences set by the factory are 3 minutes for the solution, 4 minutes for the water rinse, although other sequences are feasible.. We are in the AM process so only solenoids 421 and 422 are activated. Solenoid 421 opens for a period of 3 minutes. The air signal passes through connector 413, through line 374 to the solution manifold 354 opening the normally closed valve 393, releasing the solution.
Simultaneously valve 394 in the water manifold is closed stopping any water from entering the lines, or a backflow of solution from entering the water bottle. Also air pressure to the water bottle is equal to that of the solution bottle at all times. This also prevents a backflow. The solution now being released through line 377, passes through variable flow control 356, which releases a metered amount of solution into line 381 which is connected to the main water line of the dental unit. Solenoid 422 sends an air signal through connector 411 of the control 10, through interconnect line 373 to the unit module 30, through connector 360 on the unit module 30, through the now open side of the water coolant routing valve 291, through connector 281 to the existing dental unit water coolant valve, causing it to open allowing fluids to pass through the normal dental unit water passages and exit through the dental unit handpiece hoses into a receptacle. It also activates interconnecting line 384, which is connected to the pilot 293 of the syringe drain valve 294, and causes the normally closed syringe drain valve 294 in the unit module 30 to open allowing the fluids to circulate trough the Y fitting located inside the syringe handle located on the dental unit. The fluids enter the unit module 30 through connector 284 passing through valve 294 exiting through connector 285, which is connected to a drain or vacuum system.
Figures 4H, 5H and 6C show the AFDS control module, bottle assembly and unit module respectively in the state in which the AFDS operator selects the AM cycle following step 314 of the AM cycle. This corresponds to step 315 of the AM cycle as shown in the method flowchart, Figure 3. This also corresponds to column H labelled "4-7 min" in Tables 4 and 5, and to column C in Table 6 above.
At the end of 3 minutes, solenoid 421 will close and exhaust the air pressure in line 374 causing solution manifold valve 393 to close, and water manifold valve 394 to open. Valve 394 releases water through line 380 which passes through valve 351. Line 380 now joins line 379 which passes through the now open side of routing valve 352 through the flow control 355 which meters the amount of water entering AFDS fluid outlet line 381. Solenoid 422 was activated at the same time as solenoid 421. Solenoid 422 was timed for 7 minutes, and thus their are 4 minutes left when solenoid 421 terminates (note that all described sequence times are approximate, and represent the current best mode).
Figures 4H, 51 and 6C show the AFDS control module, bottle assembly and unit module respectively in the state in which the AFDS awaits operator intervention following step 315 of the AM cycle. This corresponds to steps 327 and 316 of the AM cycle as shown in the method flowchart, Figure 3. This also corresponds to column A in Table 4, column I in Table 5, and column C in Tables 6, each labelled "end cycle".
At the end of the 7 minute time period, solenoid 422, and indicator 847 terminate. The cycle complete indicator 844 will illuminate and the piezo alarm will sound. The cycle complete indicator 844 and the piezo alarm work in the AM selection position only. The AFDS will now wait for operator intervention. The operator will then turn the AFDS control 442 to the off position, which releases the dental unit for use, and discharges the solution bottle pressure as a safety precaution.
The operator will now turn the AFDS master valve to off. The dental unit will be released and is ready for use. The AFDS uses only one line 381 to deliver fluids (water, solution, air) to the dental unit. The AFDS contains no check valves. The system warns of low fluid levels through indicator 818 and by the piezo alarm. If there is a power failure while the AFDS is in process it will automatically switch to its battery backup and continue on without interruption. The AFDS system warns the operator if the batteries are low and need to be replaced.
Figure 7 is a simplified circuit diagram depicting a first embodiment of the electronic controller of the AFDS employing an integrated circuit micro-controller (programmable microprocessor) and single chip solenoid driver. Figure 7 shows the AFDS electronic controller board 433 (also referred to as "board", or "PC Board" 433 in Fig. 4) by means of a simplified conventional circuit diagram showing the components and connections of the current best mode controller board of the invention. The nature and functional relationships of the components shown will be apparent to one of ordinary skill in the art. The controller board is based on a programmable microprocessor 710 comprising at least one IC chip or integrated circuit. The microprocessor 710 interfaces with (I/O functions) the AFDS control module 10 by means of a plurality of switches, shown collectively as 720, ( 721-725) and corresponding to the air switches 429-432 shown in Fig. 4, an optional low bottle fluid level switch connector 725, and preferably upgrade option switch connectors 724 to take advantage of the programmable nature of the microprocessor. A combined AM/PM switch is shown, since the versatility of the microprocessor software allows these input functions to optionally be combined in single switch, although separate switches may be used to correspond directly with airswitches 431 and 432 shown in Fig. 4. Also optionally direct mechanical-electrical switches may be substituted for the pneumatic air switches of Fig. 4.
The microprocessor 710 also interfaces with the AFDS control module 10 by means of a solenoid driver chip 730 which drives a plurality of solenoids located in the AFDS control module 10 (solenoids 421, 422, 423 in Fig. 4) by means of a plurality of conventional electrical plug connectors 740 (in the current best mode of the board 433, the board plug (Fig. 7) to control module (Fig. 4) connections are 741 to 424; 742 to 425; and 743 to 426. The driver chip 730 also drives piezoelectric audio device 750 which provides monitoring alerts to the AFDS operator. The microprocessor 710 also outputs monitoring information to the AFDS operator by means of a plurality of LEDs, shown collectively as 760. These correspond to the LED shown in Fig. 4 as 843-848.
The board and its components are powered by a switchable regulated power supply 770. In the best mode shown, the power supply includes voltage reduction, rectification and regulation from a 120V/12V AC power source (optionally 240V/12V) to dual system power of approximately 12 V and 5 V d/c suitable for the various components as shown. The power supply also includes a built-in automatic battery backup and battery voltage regulator/booster to permit uninterrupted AFDS service in the event of power failure, and to extend useful battery life. The microprocessor 710 controls all the automatic timing and sequencing functions of the control module 10 and consequently of the AFDS as a whole. The available memory, processing and I/O capability of modern IC microprocessors allow a inexpensive controller to support a wide range of programmable process options, such as the optional air purge step 330 shown in Fig. 4. The AFDS microprocessor 710 can also be conveniently programmed to adapt the sequence and timing to optimally employ a wide range of solution compositions. Figure 8 shows an alternative AFDS electronic controller board 433a (also corresponding to "PC Board" 433 in Fig. 4). This is an alternative embodiment employing discrete solid state electronic components and MOSFET solenoid drivers, and it is illustrated by means of a simplified conventional circuit diagram showing the components and connections of the alternative controller board of the invention. The nature and functional relationships of the components shown will be apparent to one of ordinary skill in the art. The controller board is based on a plurality of integrated circuits, shown as 811, 812, and 813, which perform the timing and sequencing functions of the board 433a.
The input/output functions are generally comparable to those of the microprocessor board 433 shown in Fig. 7. A plurality of input switches 821-824 are shown, corresponding to the airswitches 429-432 in Fig. 4. Likewise a plurality of LEDs shown collectively as 860a, b, and c correspond to the LEDs 843-848 of Fig. 4. The solenoids 421-423 of the control module 10 are driven by MOSFET devices 831-833 which are controlled by the ICs 811-813. The MOSFET outputs are by means of electrical connectors 873-875. Figure 9 is an exploded isometric of the universal bi-directional pinch valve assembly
900 employed in all three modules, CM, BA and UM of this invention. The valve assembly 900 comprises a hollow tubular body 910, a piston 920, and an endcap 940, together with fluid lines 931 , 932 and actuator line 960.
The valve body 910 has a cylindrical bore 911 which is closed at end 912. An actuator air inlet 913 communicates with the bore 911 adj acent to the end 912 and connects to an acuator air tube 960.
The cylindrical piston 920 is sealingly housed within bore 911 by means of a sealing ring or quad ring 922 around the end the piston adjacent lower end 922. Thus the actuator air input at 913 is disposed to drive piston 920 upwards in the bore 911. The piston is retained by return spring 924 and end cap 940 at the upper end of the piston 921, and the end cap is fixed by cap retaining pins 914 inserted in body holes 915a and cap holes 915b. The assembly is mounted to mounting bracket 950 by mounting screw 951 fastened to threaded hole 941.
The body is penetrated by holes 916 to permit the threading of one or two fluid tubes 931 , 932 and has a pin P2 927 moimted across the bore 911 between the tubes at right angles to the tubes. The piston 920 has a slot 934 through it which allows the tube 931,932 and the pin P2 927 to pass through the piston as assembled. Two anvil pins PI 926 and P3 928 are mounted at each end of the slot parallel to pin 927. The clearances in the slot are selected so that as the piston is held by the return spring in contact with end 912, tube 932 is pinched shut between pins 928 and 927. When actuation air pressure is applied to the inlet 913 , the piston is driven to the end cap 940 to pinch closed tube 931 between pins 926 and 927, simultaneously unpinching tube 932. The valve may be use with either tube 931, tube 932, or both, as an n/c, n o or bi-acting valve.
INDUSTRIAL APPLICABILITY: It should be understood that various modifications within the scope of this invention can be made by one of ordinary skill in the art without departing from the spirit thereof.
For example, any of a number of disinfectant, antimicrobial, or sterilizing fluids may be used as the disinfectant solution, although it is currently accepted in the field that a 10% solution of commercially available bleach is appropriate for such purposes. (Note that commercial grade bleach contains 5.5% sodium hypochlorite solution, and so the appropriate concentration of sodium hypochlorite is approximately 0.05%.) Other solutions include alcohol, peroxide, ozone, betadyne and the like, aqueous disinfectant solutions, zinc containing microbial lipid antagonists, or a combination thereof.
Although the present invention has been described herein as being useful primarily with dental equipment, it is equally useful for use with general medical equipment or in any application wherein it is desirable or necessary to keep fluid delivery lines free of microbial growth during periods of low or non-use. The AFDS of the present invention may be utilized in essentially any application wherein conventional dental units are used. Since the AFDS of the present invention may be readily constructed and readily compatible with existing hardware, as a retrofit or integrated into a new dental unit design, it provides an important new means and method for preventing dangerous microbial growth, particularly in dental and medical equipment. It is evident that the utility and medical applicability of the invention will be both significant in scope and long-lasting in duration.
It should be understood that various modifications within the scope of this invention can be made by one of ordinary skill in the art without departing from the spirit thereof. I therefore wish my invention to be defined by the scope of the appended claims as broadly as the prior art will permit, and in view of the specification if need be.

Claims

I claim:
1. Automated method of operating a flush system apparatus for control of microbial contaminant propagation, which apparatus is manifolded to a delivery device having a consumable water or aqueous solution delivery line such as to a refrigerator, water cooler or fountain, drink dispenser, coffee maker, water treatment or filtration system, potable process water device, dishwasher, dental unit, barber or hair dressing station, and the like, comprising the steps in any operative sequence of: a) providing at least one reservoir source of antimicrobial treatment solution, or medical grade or distilled water, connectable by a single fluid delivery line to a manifold for said consumable water or water solution delivery device; b) initiating power to said flush system apparatus; c) initiating a first flush cycle which includes automatically, simultaneously or sequentially: i) pressurizing at last said antimicrobial treatment solution reservoir; ii) locking out at least one operating control of said consumable water or aqueous solution delivery device to prevent operation of said device during antimicrobial flushing; d) automatically flushing said fluid delivery line at least to said manifold with said treatment solution from said treatment solution reservoir for a predetermined period at a predetermined first rate or volume schedule at an operator initiated time or preselected clock time and date; e) rinsing said fluid delivery line with medical grade or distilled water from said reservoir for a predetermined period at a predetermined second rate or volume schedule; and f) releasing the lock out of said delivery device after completion of said rinse step to permit dental unit operation.
2. An automated method as in claim 1 which includes the added step(s) of automatically purging said single line with a gas prior to step d) or after step e) for a predetermined period at a predetermined third rate or volume schedule.
3. An automated method as in claim 1 wherein both said water and said treatment solution reservoirs are pressurized upon said power initiation step.
4. An automated method as in claim 2 wherein both said water and said treatment solution reservoirs are pressurized upon said power initiation step.
5. An automated method as in claim 1 which includes the added step of automatically maintaining said flush system in a powered-on state with delivery device lock out until operator intervention.
6. An automated method as in claim 5 wherein said intervention is selected from releasing said delivery device lock out, initiating a second flush cycle, or combinations thereof.
7. An automated method as in claim 6 wherein said operator intervention comprises initiating a second flush cycle comprising at least said steps d) and e).
8. An automated method as in claim 7 which includes the step of maintaining said flush system in a powered-on state with delivery device lock out until further operator intervention.
9. An automated method as in claim 8 which includes the step of releasing said lock out while maintaining said water reservoir pressurized.
10. An automated method as in claim 9 wherein: a) said delivery device is a dental unit, the DUWL of which is replaced by said single fluid delivery line, said manifold is a dental unit water manifold, and said dental unit is the delivery device locked out; and b) which includes the added step(s) of removing dental unit accessories selected from handpieces, syringes, cavitron tips, air sealers, and/or cup filters, from the ends of their respective water supply hoses and flushing said accessory supply hoses pursuant to said automated flush cycle.
11. An automated method as in claim 7 which includes the added step(s) of automatically purging said single line with a gas for a predetermined period at a predetermined rate or amount schedule before the initiation of the second cycle treatment solution flush.
12. An automated method as in claim 1 wherein said first rate schedule includes a hold period wherein said treatment solution is maintained in said single line for an extended period.
13. An automated method as in claim 1 wherein said rinse is automatic.
14. An automated method as in claim 1 which includes the added steps of monitoring the level of microbial content in said consumable water or aqueous solution and initiating said flush cycle upon reaching or exceeding a predetermined level of microbial contamination.
15. An automated method as in claim 1 wherein said consumable water or solution water is potable water.
16. An automated water line treatment apparatus for control of microbial growth in consumable water or aqueous solution delivery lines of a delivery device such as for a refrigerator, water cooler or fountain, drink dispenser, coffee maker, water treatment or filtration system, potable process water system, dishwasher, dental unit, barber and hair dressing station and the like, comprising in operative combination: a) a microprocessor controller for controlling dispensing of plural different fluids selected from consumable water and aqueous solutions, treatment liquids and at least one gas in a plurality of predetermined sequences of time, volume or flow rates at operator initiated time or preset clock time and date; b) at least one gas-pressurizable liquid reservoir; c) a single fluid delivery line for delivery of said consumable water or aqueous solution to or through said delivery device; d) a plurality of pinch and solenoid valves for controlling fluid valve signals and treatment fluid flow; e) said single fluid delivery line is connected to said reservoir to permit introduction of the fluids into said single fluid delivery line; and f) said microprocessor controls said valves to cause lock out of operation of said delivery device and introduction during said lock out of at least one treatment fluid from said reservoir into said single fluid delivery line for at least one predetermined timed period in at least one predetermined rate or volume schedule at operator selected time or preselected clock time and date to flush and rinse said delivery device water or aqueous solution delivery lines for control of microbial contaminants propagating or introduced therein.
17. An automated water line treatment apparatus in claim 16 which includes at least a pair of pressurizable reservoirs, a first for containing a treatment liquid and a second for containing medical grade or distilled water, preselected sequenced delivery of which is controlled by said microprocessor.
18. An automated water line treatment apparatus as in claim 17 wherein selected valves are pneumatically actuated by said microprocessor controlling a regulated air supply to said valves in accord with said schedule, and which schedule includes delivery of purge air to said single line either before introduction of said treatment solution or after said rinse solution.
19. An automated water line treatment apparatus as in claim 18 wherein said microprocessor controller schedule includes automatically maintaining said delivery device in a locked out state until operator intervention selected from release of said lock out, initiating a second flush cycle, or combinations thereof.
20. An automated water line treatment apparatus as in claim 19 which includes user control means and cycle status indicator devices responsive to states of the valves or microprocessor.
21. A programmable microprocessor circuit for automated sequencing and timing of an antimicrobial water or aqueous solution line flush system comprising in operative combination the elements depicted in and functionally interconnected as in Fig. 7.
22. A programmable microprocessor circuit for automated sequencing and timing of an antimicrobial water or aqueous solution line flush system comprising in operative combination the elements depicted in and functionally interconnected as in Fig. 8.
23. An improved pneumatic pinch valve comprising in operative combination: a) a housing having at least one fixed internal anvil member and a terminated bore; b) a moveable spool including at least one pin for pinching a tube closed against said anvil stop and said spool is disposed slidably sealed in said housing bore; c) at least one inlet and outlet in said housing aligned with at least one bore in said spool for receiving at least one tube therethrough; d) pneumatic fluid inlet disposed adjacent one end of said bore for actuating movement of said spool; e) a return spring disposed at a second end of said bore in contact with said spool; and f) said inlet, outlet, spool, anvil, pin, spring and inlet are arranged relative to each other in said housing with multiple tubings routed through said inlet and said outlet and between said pins and said anvil so that said spool may operate, upon pneumatic actuation, to normally close or to normally open one or more of said tubings, or biact to normally close at least one tube while simultaneously normally opening at least one other of said tubes.
24. A pinch valve as in claim 23 wherein: a) there is a least one inlet; b) there are at least two outlets; c) there are at least two pins; d) at least two tubes may be threaded from said inlets to said outlets, each adjacent a different one of said pins; and e) said spool biacts so that one tube is pinched closed when the other is open.
PCT/US1997/022697 1996-11-30 1997-11-29 Single line automatic fluid delivery system for dental unit water line treatment WO1998024007A1 (en)

Priority Applications (4)

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US3231396P true 1996-11-30 1996-11-30
US60/032,313 1996-11-30
US08/795,218 US5836483A (en) 1997-02-05 1997-02-05 Self-regulating fluid dispensing cap with safety pressure relief valve for dental/medical unit fluid bottles
US08/795,218 1997-02-05

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