Water purification pack

Abstract

An apparatus and methods are disclosed for purifying fluid, such as potable water, to quality levels suitable for medical application, particularly to applications involving injection of the fluid into a human body. The apparatus comprises a portable purification pack constructed for a single use. The pack houses depth filtration, activated carbon, mixed bed ion exchange resins and terminal filtration stages in series. The terminal filter comprises a fine (microfiltration or ultrafiltration), permeable membrane, treated with an endotoxin-binding chemistry. In contrast with semi-permeable osmotic membranes, the permeable membrane produces high flow rates at relatively low pressures, while still safely purifying fluid to injection quality.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of co-pending U.S. application Ser. No. 10 / 339,702, filed Jan. 8, 2003, which is a divisional of U.S. application Ser. No. 09 / 364,631, filed Jul. 30, 1999, now U.S. Pat. No. 6,719,745, issued Apr. 13, 2004, which is a continuation-in-part of U.S. application Ser. No. 09 / 277,448 filed Mar. 26, 1999, now U.S. Pat. No. 6,274,103, issued Aug. 14, 2001.FIELD OF THE INVENTION [0002] The invention generally relates to water purification, and more particularly to devices and methods for purifying water to a quality suitable for medical applications. BACKGROUND OF THE INVENTION [0003] Various medical conditions require treatments that call for the injection of fluids into the human body. For example, severe trauma to the human body often involves significant loss of bodily fluids. Additionally, illnesses often cause diarrhea followed by dehydration and ion imbalance. In order to rehydrate the individual, inject...

AI Technical Summary

Problems solved by technology

For example, severe trauma to the human body often involves significant loss of bodily fluids.

Additionally, illnesses often cause diarrhea followed by dehydration and ion imbalance.

Moreover, it is impractical to formulate and mix dialysis solutions on site at the typical location of administration, such as the patient's home.

Unfortunately, dialysis solutions are not stable in solutions over time.

For example, dextrose has a tendency to caramelize in solution over time, particularly in the concentrations required in the peritoneal dialysis context.

While achieving the desired goal of stabilizing dextrose in solution, the pH of acidified peritoneal dialysis solutions tends to damage the body's natural membranes after extended periods of dialysis.

Additionally, the use of acidified peritoneal dialysates tends to induce acidosis in the patient.

Bicarbonates introduce further instability to dialysis solutions.

Even in the absence of calcium or magnesium salts, dissolved sodium bicarbonate can spontaneously decompose into sodium carbonate and CO2, undesirably lowering the solution's pH level.

Another aspect of this problem is the need for producing injectable quality water or other diluent at the point of administration.

While separating provision of injectable quality fluid from other constituents can simplify transportation and delay production of unstable solutions, transporting purified water to the site of administration, even if produced and shipped separately from dry reagents, can represent considerable costs, as well as introducing opportunities for contamination.

Transportation costs and contamination are particularly problematic when fluids are to be administered outside of a controlled hospital or clinic environment.

Problems are even further exacerbated in lesser-developed countries, such as in the Indian subcontinent and Africa.

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