Liquid purification or separation – Recirculation – Serially connected distinct treating or storage units
Reexamination Certificate
2000-05-12
2001-10-02
Kim, John (Department: 1723)
Liquid purification or separation
Recirculation
Serially connected distinct treating or storage units
C210S085000, C210S090000, C210S097000, C210S194000, C210S321710, C210S636000, C422S001000, C422S038000
Reexamination Certificate
active
06296762
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to methods and apparatus for preparing solutions for medical purposes. More particularly, the present invention relates to such methods and apparatus for preparing dialysis solutions and/or replacement solutions for use in hemodialysis, hemodiafiltration or hemofiltration, as well as other liquids for medical use, such as infusion solutions, peritoneal dialysis solutions, nutritional solutions, and the like. Still more particularly, the invention relates to methods for disinfecting such apparatus and vessels intended for use in such apparatus
BACKGROUND OF THE INVENTION
In dialysis clinics for hemodialysis, large numbers of patients are treated simultaneously. Each patient is thus connected to a dialysis machine, a so-called monitor, which prepares the dialysis solution and administers the solution to a dialyzer, which is connected to the patient.
In monitors which are presently in use, such as the GAMBRO AK-100 monitor, preparation of the dialysis solution normally takes place by mixing two dialysis concentrates to produce a desired composition and concentration.
The dialysis concentrate can be an A-concentrate, which consists of acetic acid, sodium chloride, potassium chloride, calcium chloride and magnesium chloride, and a B-concentrate, consisting of bicarbonate. Reference is made to European Patent No. B1-0 278 100 for further details thereof.
These concentrates are diluted with water, which is normally obtained from a particular water outlet at each treatment location. The water must be specially treated so that it contains as few impurities as possible, and is normally prepared by the so-called RO (reverse osmosis) process. Such a process is described, for example, in European Patent Nos. B1-0 058 303 and BI-0 058 304.
The water is usually purified at a central location, and is conducted to each patient location in a particular conduit system which is constructed with the intention of reducing the possibilities of bacterial contamination. Furthermore, the conduit system is regularly disinfected by feeding warm water, at a temperature above 90° C., through the system.
German Patent No. A1-34 43 911 describes a method and an apparatus for the batchwise preparation of a dialysis solution consisting of common salt, magnesium, calcium, potassium and glucose by mixing with so-called “zero-conductivity water,” i.e., purified water, in a large tank. The thus-prepared dialysis solution is then drained into containers of about 10 liters each, and placed at the dialysis clinic's disposal to form the above-mentioned A-concentrate after the addition of acid (which can take place in the monitor itself). The disadvantage with this process is that heavy concentrate-containing containers must be physically handled by the personnel and transported or carried to each patient location.
German Patent No. C2-42 03 905 describes the distribution of a centrally prepared dialysis solution by means of a conduit system. The disadvantage with such central distribution of dialysis solution is that the dialysis solution is a very good nutritional medium for many bacteria. According to German Patent No. C2-42 03 905, a sterile filter is employed, though this can become quite expensive. Furthermore, very effective disinfection of the conduit system is required. The conduits must first be rinsed clean to remove the dialysis solution, after which hot water or other disinfecting agents are circulated through the conduits.
SUMMARY OF THE INVENTION
One object of the present invention is to propose a practical and useful method and apparatus for centrally preparing solutions or concentrates intended for dialysis or similar medical purposes.
A saturated concentrate solution of sodium chloride, common salt, is a very poor nutritional medium for bacteria, and only a small number of bacteria are known which can survive in such an environment, i.e., so-called halo bacteria.
In addition, a saturated common salt solution may be heated to high temperatures without its properties or solubility being altered.
It has also been shown to be possible to continuously prepare a saturated common salt solution starting from a large quantity of common salt in powder form by means of passing water through the quantity of powder. If the grain size of the common salt crystals lies within a predetermined range, no formation of lumps of common salt occurs even with very large quantities of salt, something which otherwise could be expected. (See European Patent No. B1-0 278 100).
In accordance with the present invention, these objects have now been realized, and the characteristics discussed above have now been utilized by the invention of a method for the central preparation and distribution of a concentrate to a plurality of medical treatment devices comprising supplying a liquid stream comprising substantially only water to a central container including substantially only a single salt composition at least partially in solid form therein, producing a substantially saturated solution of said salt composition in said central container, and distributing said salt solution to a distribution conduct, the distribution conduct including a plurality of concentrate connectors whereby the salt solution can be distributed to the plurality of medical treatment devices.
In accordance with one embodiment of the method of the present invention, the method includes preparing a medical treatment solution from the salt solution in each of the plurality of medical treatment devices. Preferably, the medical treatment solutions include dialysis solutions and replacement solutions for hemodialysis, hemofiltration and hemodiafiltration.
In accordance with another embodiment of the method of the present invention, the method includes heating the liquid stream or the substantially saturated solution of the salt composition to an elevated temperature whereby the salt solution is distributed to the distribution conduit at that elevated temperature.
In accordance with another embodiment of the method of the present invention, the method includes adding a separate substance to the salt solution, preferably acetic acid.
In accordance with one embodiment of the method of the present invention, the medical treatment solution comprises a dialysis solution and the plurality of medical treatment devices comprises a plurality of dialysis machines, and the method includes diluting the substantially saturated salt solution and adding carbon dioxide gas to the substantially saturated salt solution prior to distributing the salt solution to the distribution conduit.
In accordance with another embodiment of the method of the present invention, the method includes distributing the salt solution to the distribution conduit at an elevated pressure.
In accordance with another aspect of the present invention, a method of disinfecting an apparatus for the central preparation and distribution of a concentrate to a plurality of medical treatment devices has been devised, comprising a central concentrate container for preparation of a substantially saturated solution of substantially only a single salt composition and distribution means for distributing the salt solution to a plurality of concentrate connectors whereby the salt solution can be distributed to the plurality of medical treatment devices, the method comprising circulating the salt solution in a recirculation circuit including the distribution means and heating the salt solution to an elevated temperature in order to disinfect the recirculation circuit thereby. Preferably, the method includes recirculating the salt solution in the recirculation circuit at an elevated pressure.
In accordance with the apparatus of the present invention, apparatus for the central preparation and distribution of a concentrate to a plurality of medical treatment devices has been devised, comprising central concentrate preparation means for preparing a substantially saturated solution of substantially only a single salt solution from the salt at least partially in solid form and a
Hallberg Birger
Jonsson Lennart
Jonsson Sven
Knutsson Stefan
Olsson Lennart
Gambro AB
Kim John
Lerner David Littenberg Krumholz & Mentlik LLP
LandOfFree
Apparatus for disinfecting a device for the central... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus for disinfecting a device for the central..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for disinfecting a device for the central... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2598807