WO2019051611A1

WO2019051611A1 - System and method for solar-powered oxygen delivery

Info

Publication number: WO2019051611A1
Application number: PCT/CA2018/051151
Authority: WO
Inventors: Michael Hawkes; Sophie NAMASOPO; Andrea Conroy; Robert OPOKA
Original assignee: The Governors Of The University Of Alberta
Priority date: 2017-09-18
Filing date: 2018-09-17
Publication date: 2019-03-21

Abstract

A system and method for solar-powered oxygen delivery involve producing concentrated oxygen with an oxygen concentrator powered, either directly or indirectly, with electrical energy generated by a photovoltaic cell, storing concentrated oxygen produced by the oxygen concentrator in a pillow tank at a pressure above atmospheric pressure, and allowing concentrated oxygen to discharge from the pillow tank through a distribution line to an outlet such as a facemask or nasal cannula.

Description

SYSTEM AND METHOD FOR SOLAR-POWERED OXYGEN DELIVERY

TECHNICAL FIELD

[0001] The present invention relates to systems and methods of oxygen delivery, and more particularly to oxygen delivery for use in oxygen therapy. BACKGROUND OF THE INVENTION

[0002] Oxygen therapy is used in hospitals to treat potentially lethal hypoxemic respiratory illness. Conventionally, oxygen for such therapeutic use is generated at a production facility and stored under high pressure in rigid walled storage cylinders, which are transported to the hospital. However, in remote and resource-poor locations, the supply chain between the production facility and the hospital can be compromised by poor transportation infrastructure, prohibitive transportation costs, and inventory management issues. Further, while the storage cylinders are relatively robust, they are also relatively cumbersome and heavy. Further still, tank regulators used to deliver a constant and metered flow of oxygen from storage cylinders to patients may be ill-fitting and poorly maintained, resulting in substantial leakage and waste of oxygen.

[0003] An alternative is to use oxygen concentrators to purify oxygen from ambient air through selective adsorption of nitrogen using molecular sieves. However, oxygen concentrators require a constant, uninterrupted electrical power supply, such as from an electrical grid or fuel-powered generator. In remote and resource-poor locations, this electrical power supply can be compromised by power outages and prohibitive fuel costs.

[0004] Thus, there remains a need in the art for reliable and economic delivery of oxygen, particularly for therapeutic use in hospitals in remote and resource poor locations.

SUMMARY OF THE INVENTION

[0005] The present invention relates to oxygen generation, storage and distribution. Any term or expression not expressly defined herein shall have its commonly accepted definition understood by a person skilled in the art. [0006] In one aspect, the present invention comprises a system for solar powered oxygen delivery. The system comprises: a photovoltaic cell for generating electrical energy; an oxygen concentrator for producing concentrated oxygen from ambient air, wherein the oxygen concentrator is, in use, powered, either directly or indirectly, with electrical energy generated by the photovoltaic cell; and a pillow tank connected to the oxygen concentrator for storing concentrated oxygen produced by the oxygen concentrator.

[0007] In embodiments of the system, the system further comprises a distribution line connected to the pillow tank for distributing concentrated oxygen stored in the pillow tank to an outlet. In embodiments of the system, the outlet comprises a facemask or a nasal cannula.

[0008] In embodiments of the system, the system further comprises an electrochemical cell for storing electrical energy generated by the photovoltaic cell, wherein the oxygen concentrator is, in use, powered indirectly with electrical energy generated by the photovoltaic cell, by storing electrical energy generated by the photovoltaic cell in an electrochemical cell, and powering the oxygen concentrator with the electrochemical cell.

[0009] In embodiments of the system, the system further comprises a charge controller for regulating one or a combination of voltage or current delivered by the photovoltaic cell to the electrochemical cell.

[0010] In embodiments of the system, the system further comprises an object disposed on the pillow tank to compress the pillow tank, and thereby increase pressure of concentrated oxygen stored in the pillow tank. The object may comprise a platform.

[0011] In another aspect, the present invention comprises a method for solar-powered oxygen delivery. The method comprises the steps of:

(a) producing concentrated oxygen with an oxygen concentrator powered, either directly or indirectly, with electrical energy generated by a photovoltaic cell; and

(b) storing concentrated oxygen produced by the oxygen concentrator in a pillow tank at a pressure above atmospheric pressure. [0012] In embodiments of the method, the method further comprises the step of allowing concentrated oxygen to discharge from the pillow tank through a distribution line to an outlet. The outlet may comprise a facemask or a nasal cannula.

[0013] In embodiments of the method, the oxygen concentrator is powered indirectly with electrical energy generated by the photovoltaic cell, by storing electrical energy generated by the photovoltaic cell in an electrochemical cell, and powering the oxygen concentrator with the electrochemical cell.

[0014] In embodiments of the method, the method further comprises the step of using a charge controller for regulating one or a combination of voltage or current delivered by the photovoltaic cell to the electrochemical cell.

[0015] In embodiments of the method, the method further comprises the step of disposing an object on the pillow tank to compress the pillow tank to maintain the pressure of concentrated oxygen in the pillow tank at the pressure above atmospheric pressure. The object may comprise a platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Exemplary embodiments of the present invention are described with reference to the following drawings. In the drawings, like elements are assigned like reference numerals. The drawings are not necessarily to scale, with the emphasis instead placed upon the principles of the present invention. Additionally, each of the embodiments depicted is but one of a number of possible arrangements utilizing the fundamental concepts of the present invention. The drawings are briefly described as follows:

[0017] Fig. 1 is a schematic depiction of an embodiment of a system of the present invention in a hospital with a patient.

DETAILED DESCRIPTION OF THE INVENTION [0018] Referring to Figure 1, an exemplary embodiment of the system (10) is installed in a hospital (100) for delivering oxygen to a patient (102). In the exemplary embodiment, the system (10) comprises a photovoltaic cell (12), an electrochemical cell (14), a charge controller (16), a power inverter (18), an oxygen concentrator (20), a pillow tank (22), a compression platform (24), and a distribution line (26) leading to an outlet (28) in the form of a facemask or a nasal cannula.

[0019] The photovoltaic cell (12) generates electrical energy, which directly or indirectly powers the oxygen concentrator (20). In the exemplary embodiment, the system (10) comprises a plurality of photovoltaic cells (12), which are arranged in an array in a solar panel that is mounted on the roof of the hospital (100). In the exemplary embodiment, suitable photovoltaic cells (12) are provided in the form of ten solar panels, each having an output of 80 Watts or 175 Watts, as produced by SolarWorld Industries Sachsen GmbH (Freiburg, Germany). [0020] The electrochemical cell (14) stores electrical energy generated by the photovoltaic cell (12) so that the electrical energy generated by the photovoltaic cell (12) can be used to indirectly power the oxygen concentrator (20). That is, the electrical energy generated by the photovoltaic cell (12) is stored in the electrochemical cell (14), which is then used to power the oxygen concentrator (20). In an exemplary embodiment, the system (10) comprises a plurality of electrochemical cells (16) in the form of a battery. In an exemplary embodiment, suitable electrochemical cells (16) are provided by four Ultra-Power ™ gel batteries, each having a capacity of 220 ampere-hours, as produced by Victron Energy BV (Almere Haven, The Netherlands).

[0021] The charge controller (16) regulates one or a combination of voltage or current delivered by the photovoltaic cell (12) to the electrochemical cell (14). In an exemplary embodiment, a suitable charge controller (16) is a FLEXmax 80 ™ model charge controller as produced by OutBack Power (Arlington, Washington), or a 40A/24V charge controller, as produced by Steca Elektronik GmbH (Memmingen, Germany).

[0022] The power inverter (18) converts direct current (DC) produced by the electrochemical cell (14) to alternating current (AC), which may be required by the oxygen concentrator (20) in exemplary embodiments. In an exemplary embodiment, a suitable power inverter (18) is produced by Victron Energy BV (Almere Haven, The Netherlands). In other embodiments where a power inverter (18) is not provided and the oxygen concentrator (20) requires AC current for operation, the oxygen concentrator (20) may be adapted with a DC motor so as to receive DC current from the electrochemical cell (14).

[0023] The oxygen concentrator (20) produces concentrated oxygen from ambient air. The art of oxygen concentrators is known to persons skilled in the art, and does not, in isolation, form the invention. In an exemplary embodiment, for example, the oxygen concentrator (20) utilizes a molecular sieve to selectively adsorb the nitrogen component from the ambient air, thus producing oxygen-enriched gas. In other embodiments, the oxygen concentrator (20) may function in accordance with alternative principles of operation. In an exemplary embodiment, a suitable oxygen concentrator (20) is a 525 KS model oxygen concentrator as produced by DeVilbiss Healthcare LLC (Somerset, Pennsylvania), with a power consumption of approximately 320 Watts, outputting concentrated oxygen having a purity of approximately 90 percent at a variable rate of between 0 to approximately 5 liters per minute.

[0024] The pillow tank (22) is connected to an outlet of the oxygen concentrator and stores the concentrated oxygen produced by the oxygen concentrator (20). As used herein, a "pillow tank" (also known in the art as a bladder tank) refers to a container having flexible walls. As non-limiting examples, the walls of the pillow tank (22) may be made with flexible materials such as textile or polymeric material such as polyvinyl chloride. In comparison with conventional rigid walled cylindrical tanks used to store oxygen, a pillow tank (22) may have a relatively low weight-to-volume ratio and can be made compact for transportation and then deployed. In an exemplary embodiment, the pillow tank (22) has a volumetric capacity of approximately 3,000 liters and is produced by Game Uganda (Kampala, Uganda).

[0025] The platform (24) is disposed on the pillow tank (22) to compress the pillow tank (22) to increase the pressure of concentrated oxygen in the pillow tank (22). The use of the platform (24) may be advantageous if the pressure of the concentrated oxygen in the pillow tank (22), without compression by the platform (24), is insufficient to drive the concentrated oxygen through the distribution line (26).

[0026] The distribution line (26) is a conduit connected to the pillow tank (22) for distributing the oxygen produced by the oxygen concentrator (20) to an outlet (28). In an exemplary embodiment, the distribution line (26) is a segment of tubing, and the outlet (28) may be a facemask or a nasal cannula for delivering the concentrated oxygen to a patient (102). In embodiments, the distribution line (26) and the outlet (28) may comprise a plurality of distribution lines and outlets for servicing a plurality of patients. In embodiments, the system (10) may further comprise a regulator for regulating the flow rate of oxygen delivered via the outlet (28) to the patient (102).

[0027] In an exemplary use of an exemplary embodiment of the system (10) as shown in Figure 1, the system (10) provides a continuous stream of concentrated oxygen at a flow rate of approximately 5 liters per minute for oxygen therapy to a patient (102) in a hospital (100). During the daytime, the oxygen concentrator (20) may be powered directly by the photovoltaic cells (12). During the night time, the oxygen concentrator (20) may be powered indirectly by the photovoltaic cells (12) using energy stored in the electrochemical cell (14). The person skilled in the art may select parameters of the system such as the number of photovoltaic cells (12) and electrochemical cells (14), and the rate of concentrated oxygen production by the oxygen concentrator (20) so that the system (10) can produce a sustained supply of concentrated oxygen for a required rate of concentrated oxygen consumption at the outlet (28).

[0028] The present invention has been described above and shown in the drawings by way of exemplary embodiments and uses, having regard to the accompanying drawings. The exemplary embodiments and uses are intended to be illustrative of the present invention. It is not necessary for a particular feature of a particular embodiment to be used exclusively with that particular exemplary embodiment. Instead, any of the features described above and/or depicted in the drawings can be combined with any of the exemplary embodiments, in addition to or in substitution for any of the other features of those exemplary embodiments. One exemplary embodiment's features are not mutually exclusive to another exemplary embodiment's features. Instead, the scope of this disclosure encompasses any combination of any of the features. Further, it is not necessary for all features of an exemplary embodiment to be used. Instead, any of the features described above can be used, without any other particular feature or features also being used. Accordingly, various changes and modifications can be made to the exemplary embodiments and uses without departing from the scope of the invention as defined in the claims that follow.

Claims

CLAIMS The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A system for solar-powered oxygen delivery, the system comprising:

(a) a photovoltaic cell for generating electrical energy;

(b) an oxygen concentrator for producing concentrated oxygen from ambient air, wherein the oxygen concentrator is, in use, powered, either directly or indirectly, with electrical energy generated by the photovoltaic cell; and

(c) a pillow tank connected to the oxygen concentrator for storing concentrated oxygen produced by the oxygen concentrator.

2. The system of claim 1 further comprising a distribution line connected to the pillow tank for distributing concentrated oxygen stored in the pillow tank to an outlet.

3. The system of claim 2 wherein the outlet comprises a facemask or a nasal cannula.

4. The system of any one of claims 1 to 3 further comprising an electrochemical cell for storing electrical energy generated by the photovoltaic cell, wherein the oxygen concentrator is, in use, powered indirectly with electrical energy generated by the photovoltaic cell, by storing electrical energy generated by the photovoltaic cell in an electrochemical cell, and powering the oxygen concentrator with the electrochemical cell.

5. The system of claim 4 further comprising a charge controller for regulating one or a combination of voltage or current delivered by the photovoltaic cell to the electrochemical cell.

6. The system of any one of claims 1 to 5 further comprising an object disposed on the pillow tank to compress the pillow tank, and thereby increase pressure of concentrated oxygen stored in the pillow tank.

7. The system of claim 6 wherein the object comprises a platform.

8. A method for solar-powered oxygen delivery, the method comprising the steps of: (a) producing concentrated oxygen with an oxygen concentrator powered, either directly or indirectly, with electrical energy generated by a photovoltaic cell; and

(b) storing concentrated oxygen produced by the oxygen concentrator in a pillow tank at a pressure above atmospheric pressure.

The method of claim 8 further comprising the step of allowing concentrated oxygen to discharge from the pillow tank through a distribution line to an outlet.

The method of claim 9 wherein the outlet comprises a facemask or a nasal cannula.

The method of any one of claims 9 to 10 wherein the oxygen concentrator is powered indirectly with electrical energy generated by the photovoltaic cell, by storing electrical energy generated by the photovoltaic cell in an electrochemical cell, and powering the oxygen concentrator with the electrochemical cell.

The method of claim 11 further comprising the step of using a charge controller for regulating one or a combination of voltage or current delivered by the photovoltaic cell to the electrochemical cell.

The method of any one of claims 8 to 12 further comprising the step of disposing an object on the pillow tank to compress the pillow tank to maintain the pressure of concentrated oxygen in the pillow tank at the pressure above atmospheric pressure.

The method of claim 13 wherein the object is a platform.