Patent ID: 12186265

DETAILED DESCRIPTION OF THE INVENTION

The detailed description set forth below in connection with the appended drawings is intended as a description of presently preferred embodiments of the invention and is not intended to represent the only forms in which the present invention may be constructed and or utilized.

It is to be appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention that are, for brevity, described in the context of a single embodiment may also be provided separately or in any suitable sub-combination or as suitable in any other described embodiment of the invention. Stated otherwise, although the invention is described below in terms of various exemplary embodiments and implementations, it should be understood that the various features and aspects described in one or more of the individual embodiments are not limited in their applicability to the particular embodiment with which they are described, but instead can be applied, alone or in various combinations, to one or more of the other embodiments of the invention.

One or more embodiments of the present invention define the phrase “medical grade” in accordance with its ordinary meaning in the medical art. For example, a medical grade matter or material are those that are biocompatible to living systems.

One or more embodiments of the present invention may use the phrase “form factor” as the physical size and or shape of various members and or components of the one or more embodiments of the isolation system of the present invention.

Throughout the disclosure the term oxygen, medical grade oxygen, air, and or air enriched with oxygen may be used interchangeably or concurrently as the isolation system is fully compatible with all such sources for medical use.

One or more embodiments of the present invention provide an isolation system that is lightweight and portable.

One or more embodiments of the present invention provide an isolation system that has a small form-factor when not used for easy storage.

One or more embodiments of the present invention provide an isolation system that is disposable.

One or more embodiments of the present invention provide an isolation system that is self-supporting with no rigid structural supports.

One or more embodiments of the present invention provide an isolation system that is compatible for applications that use medical grade oxygen.

One or more embodiments of the present invention provide an isolation system that when in an expanded state, fully encompass or encapsulate a subject.

One or more embodiments of the present invention provide an isolation system that does not use, need, or require negative pressure for isolation, but instead, uses positive pressure for isolation of subjects.

Positive pressure systems in accordance with one or more embodiments of the present invention do not require extensive internal support structures, are low cost and disposable. That is, one or more embodiments of the positive pressure isolation system of the present invention are less expensive by at least a factor of ten, not accounting for the cost burden of thorough cleaning that is required for the non-disposable negative pressure systems.

Further, one or more embodiments of the positive pressure isolation system of the present invention may be flexible (as they require internal positive pressure to inflate) and hence, they may easily be slipped over patients, whereas negative pressure systems would require and in fact, need a rigid “tent” like structures to position a patient within the isolation “tent”.

Stated simply, one or more embodiments of the present invention provide an isolation system that is low cost, portable, easily deployed, and single use disposable infectious disease containment system designed to minimize risk to patient and medical personnel while allowing patient monitoring, care, and transport (as further detailed below).

The isolation system of the present invention operates at a very low internal positive pressure (about 50 Pa) and high gas flow of about 10 to 15 liters per minute (either medical grade oxygen from a tank or −90% oxygen from an oxygen concentrator, or air).

FIG.1A to1E-11are non-limiting, exemplary illustrations of an isolation system packaging, which progressively illustrate a non-limiting, exemplary method for unpacking the same in accordance with one or more embodiments of the present invention.

As illustrated inFIGS.1A to1C, the lightweight and portable isolation system100(FIG.1D-1) of the present invention may be delivered for use to first responders in a small sized form factor in an isolation system package box252with an approximate weight of about 1815 g, having an approximate height254of about 23 mm, an approximate length256of about 30 mm, and an approximate width258of about 26 mm. Accordingly, due to their small sized form-factor, multiple isolation system packages252may be stored in vehicles for use for safe transportation of patients.

It should be noted that the use of isolation system package box252may be optional as isolation system100is already packaged inside as an isolation system kit132enclosed in a plastic bag (e.g., a Ziploc® bag)260, as best shown inFIGS.1B and1C. However, use of an isolation system package box252is preferred as it provides rigidity for added protection for the internally stored isolation system kit132.

As best illustrated inFIGS.1B and1C, the lightweight and portable isolation system100is further packaged as isolation system kit132inside a closed plastic bag (e.g., a Ziploc® bag)260with a readily visible instruction sheet262for simple and easy use.

The entire isolation system packaging is very low cost, providing immediate savings to medical facilities and further, meets jurisdictional quarantine protocols, including having an unattended storage life of about 5 years.

FIGS.1D-1to1D-8are non-limiting, exemplary illustrations of components of isolation system kit132opened and unpacked. It should be noted that isolation system kit132and all its components are medical grade cleaned (standard IEST-STD 1246D Level 100 clean), but not sterile.

As illustrated inFIGS.1A to1D-8, isolation system100within isolation system kit132includes a medical grate polymer (i.e., polyethylene) membrane102, which is wrapped around a rolling member266(further detailed below). Further included is a conventional medical grade oxygen rated inflow tube114(approximately 1 m), an exhaust filter assembly118, and a medical grate hose barb adapter264.

As best shown inFIGS.1D-6to1D-8, exhaust filter assembly118includes a medical grade oxygen rated outflow tubing128(approximately 0.2 m), a HEPA filter sub-assembly134, including HEPA filter228and filter protective output plug120connected to output end122.

FIGS.1E-1to1E-11are a non-limiting, exemplary illustration of a deflated polyethylene membrane102of the isolation system shown inFIGS.1A and1D-8in accordance with one or more embodiments of the present invention. As illustrated, once removed from kit132, medical grade polyethylene membrane102may be unfurled (FIGS.1E-1to1E-4) and spread open (FIGS.1E-5and1E-11).

As best shown inFIGS.1E-1to1E-3, a rolling member266configurated as a generally cylindrical foam is used to wrap membrane102to prevent seal member106from being kinked as membrane102is rolled into a small form-factor for packaging and storage.

Since rolling member266is a soft, cushiony “spongy” foam, it may be used as a head rest “pillow” or knee bolster, etc. during transport of a patient either with the patient inside membrane102or outside of membrane102.

It should be noted that the use of rolling member266is preferred but is optional as the kinking would not damage seal membrane106. However, it would generally make closure of seal member106more difficult to use. Accordingly, the entire membrane102may be folded around a smaller sized diameter rolling member266or simply folded flat (rather than rolled) into a much smaller and more compact form-factor, requiring a smaller kit and box packaging if rolling member is not used.

As further detailed below, a first port110of membrane102and a second port112of membrane102may be covered over by protective foam covers268(FIG.1E-4) when packaged for delivery so that first and second ports110and112do not break or accidentally puncture membrane102as it is rolled into its small sized packaging.

FIG.1E-5illustrates first and second ports of membrane102with protective foam covers268andFIG.1E-6illustrates first and second ports of membrane102with protective foam covers268removed.

As further detailed below, depending on jurisdictional requirements a set of warning/instruction labels270may be positioned adjacent one or both first and or second ports110and112.FIG.1E-7is an exemplary illustration of opening104of membrane102, including sealing member106, all of which are further detailed below.

As further illustrated inFIGS.1E-8to1E-11, medical grade polyethylene membrane102has open end104that includes seal member106that enables access to its internal cavity or chamber and may be used to cover a patient over, surround, and seal off a patient.

It should be noted that medical grade oxygen rated inflow tube114, medical grade oxygen rated outflow tube128, and exhaust filter assembly118are not connected to the polyethylene membrane102while in isolation system kit132.

As detailed below, the medical grade oxygen rated inflow tube114, medical grade oxygen rated outflow tube128, and exhaust filter assembly118may be connected after the polyethylene membrane102is removed from isolation system kit132, unfurled and spread open (FIGS.1E-5to1E-11).FIG.1E-9further illustrates connecting an end of medical grade oxygen rated inflow tube114to an oxygen sourced regulator valve116(may optionally use hose barb adapter264).

FIGS.1E-10and1E-11are close up illustrations of connections of inflow tube114and outflow tube128to respective first and second ports110and112.FIGS.2A-1to2A-13illustrate a preferred method in the order of connection of various components.

FIGS.2A-1to2A-13and2B-1to2B-7, are non-limiting, exemplary illustrations of the isolation system shown inFIG.1A to1E-11, progressively illustrating a non-limiting, exemplary methods for fully sealing and isolating a patient in accordance with one or more embodiments of the present invention.

In particular,FIGS.2A-1to2A-13illustrate isolating a patient108within polyethylene membrane102with feet first whereasFIGS.2B-1to2B-7illustrate isolating patient108within polyethylene membrane102with head first. Various components of isolation system100are further described in relation toFIGS.2A-1to2B-7.

As illustrated inFIG.2A-1to2A-13, after unpacking isolation system100as detailed above, membrane102should be positioned flat with first and second ports110and112facing upward (as shown inFIGS.1E-5to1E-9).

Next, exhaust filter assembly118may be attached to second port112as shown inFIG.2A-1. That is, free end284of outflow tubing128of exhaust filter assembly118may be connected to the port (110or112) nearest the patient's feet.

In this non-limiting, exemplary instance, second port112is to be used as the “outlet” port of isolation system100as it is the closest port to the patient's feet and the patient head will be near the opening106of membrane102. Free end284of outflow tubing128of exhaust filter assembly118may be connected to second port112by sliding free end284over hose barb282of second port112in the direction shown by arrows280. As further detailed below, at this stage it is best-practice if filter protective output plug120is not removed to initially quickly inflate polyethylene membrane102.

As best illustrated inFIG.2A-2, one of the ends286of inflow tube114may be attached to regulator valve116of a source276of oxygen (or oxygen concentrator) or air, etc. via hose barb adapter264.

As best shown inFIGS.2A-3and2A-4, membrane102may be maneuvered by a first responder272at its open end106to encapsulate a patient108. Patient108may be sitting upright in a chair (FIG.2A-1) or in a prone or supine position (FIG.2A-2), with polyethylene membrane102maneuvered (shown by arrow274inFIG.2A-2) by first responder272to cover the patient to commence isolation from the feet first to the head to complete the covering of patient108with polyethylene membrane102(FIG.2A-5).

As best illustrated inFIG.2A-5, both first and second ports110and112must be aligned (as shown by the illustrated phantom alignment lines278) on the front middle plane of patient108. It should be noted that inFIG.2A-5, the connection of inflow tube114to oxygen or air source276is intentionally not shown for clarity.

As shown inFIG.2A-6, prior to sealing membrane102the other end286of inflow tube114is connected to first port (in this instance, inlet port)110. As detailed inFIG.2A-2, the other end (upstream end)286of inflow tube114is already connected source276of oxygen or air. Accordingly, prior to closing off sealing member106to seal off and isolate patient108, a second or downstream end of a medical grade oxygen rated fill tubing114that is included in the kit is used and connected to one of a first port110and a second port112, depending on head position of patient108inside the polyethylene membrane102.

As detailed below, polyethylene membrane102includes first port110and second port112, either one of which may be used as the “inlet” or the “outlet” port depending on the position of the head of patient108in relation to the nearest port. In the non-limiting, exemplary instance shown inFIGS.2A-1to2A-13, first port110is to be used as the “inlet” port as it is the closest port to the patient's head and hence, second or downstream end of medical grade oxygen rated fill tubing114is connected to hose barb282of first port110.

Thereafter, as best shown inFIG.2A-7oxygen or air regulator valve116may be opened to commence inflating membrane102. As further detailed below, the initial flow rate may preferably be set at about 15 liters per minute (Um) into membrane102cavity or chamber.

As shown inFIG.2A-8, a first responder may than simply seal off membrane102using sealing member106as shown. That is, as a final step for isolating patient108within polyethylene membrane102, sealing member106may be closed off to seal off and isolate patient108while medical grade oxygen continues to fill the polyethylene membrane102via regulator valve116.

At this stage, polyethylene membrane102expands to inflate from a contracted state having a small form-factor to an expanded (inflated) state, defining an internal chamber that may be used to encapsulate and wholly encompass the entire body of patient108. As illustrated throughout the disclosure, polyethylene membrane102has no rigid structures to maintain it in its expanded state and hence, it operates based on internal positive pressure, is simple to manufacture, is stored in a compact, small form-factor inside kit132, and very simple to use.

As further illustrated inFIG.2A-9, patient's transfer (of duration of no more than an hour or so) may commence while membrane102continues to inflate (as shown inFIG.2A-9).

As shown inFIG.2A-10, once membrane102is sufficiently inflated to an internal positive pressure PMemof about 50 Pa, filter protective output plug120should be removed from output end122. The removal of filter protective output plug120would allow for exhaust of gases202from within membrane102via exhaust filter assembly118. At this stage, it is preferred if the input flow rate of the medical grade oxygen or air is readjusted and regulated to about 10 liters per minute to 15 liters per minute, sufficient to prevent excessive water vapor and carbon dioxide build up within membrane102.

InFIG.2A-10illustrates patient108as fully isolated in the inflation process, at approximately 80% inflation, with oxygen or air inflows shown by arrows198, exhaust outflows shown by arrows202, and safe to breathe, uncontaminated air flowing out of exhaust filter assembly118shown by arrows204.

FIGS.2A-11to2A-13, are non-limiting, exemplary illustrations of procedures for extraction of the patient from membrane102in accordance with one or more embodiments of the present invention. As illustrated, once the final destination is reached (e.g., a medical facility such as a hospital), the flow of oxygen or air may be stopped (FIG.2A-11), with inflow tube114disconnected from first (e.g., inlet) port110.

Thereafter, membrane102may be unsealed by unfastening sealing member106or by slicing membrane102using scissors to remove patient (FIG.2A-12). Thereafter, prior to removal of patient108, it is best practice to allow a few seconds (e.g., approximately 15 to 30 seconds) for gas currents (if any) within membrane102to dissipate. Once the patient108is removed, the entire isolation system100may be disposed of as shown inFIG.2A-13.

These simple, quick, and easy steps taken by first responders272shown inFIGS.2A-1to2A-13quickly and easily isolate patients108while enabling first responders272to continue maintaining visual observation of the patient (via the clear, thin, transparent polyethylene membrane102) to assure comfort and management of patient, including making sure that the inflow of medical grade oxygen continues unabated into the polyethylene membrane102. It should be noted that patients108and first responders272may also easily communicate with one another while patient108is fully isolated inside membrane102.

FIGS.2B-1to2B-7are non-limiting, exemplary illustrations of encapsulating a patient within polyethylene membrane102with head first in accordance with one or more embodiments of the present invention. The method steps or operations illustrated inFIGS.2B-1to2B-7are similar to those shown inFIGS.1A to2A-13, and described above. Therefore, for the sake of brevity, clarity, convenience, and to avoid duplication, the general description ofFIGS.2B-1to2B-7will not repeat every corresponding or equivalent component, interconnections, functional, operational, and or cooperative relationships that has already been described above in relation toFIGS.1A to2A-13but instead, all are incorporated by reference herein.

As illustrated inFIGS.2B-1to2B-7, in this non-limiting, exemplary instance, actions are taken to surround patient108with polyethylene membrane102when applied from the head to the feet. In this instance, a patient108may be standing upright next to a bed for example, where the polyethylene membrane102may be used to seal patient108from the head first to the feet to complete the covering of patient108with polyethylene membrane102.

As shown inFIGS.2B-1to2B-3, in this non-limiting, exemplary instance, one end286of the medical grade oxygen rated fill tubing114is connected to second port112, which is to be used as the “inlet” port as it is the closest port to the patient's head. Exhaust filter assembly118is connect to first port110. In this non-limiting, exemplary instance first port110is to be used as the “outlet” port as it is the closest port to the patient's feet.

As further illustrated inFIGS.2B-4to2B-6, membrane102may be maneuvered by a first responder272at its open end106to encapsulate a patient108. Patient108may be sitting or standing upright (FIG.2B-4) or in a supine or prone position (FIGS.2B-5and2B-6), with polyethylene membrane102maneuvered by first responder272to fully cover patient108to commence isolation from the head first to the feet to complete the covering of patient108with polyethylene membrane102(FIG.2B-7).

Once patient108is moved into polyethylene membrane102, first and second ports110and112are aligned to lie approximately on the frontal mid-plane of patient108as indicated above.

In this non-limiting, exemplary instance, seal member106is at the feet of patient108instead of adjacent the head. The remaining steps are identical to those described above in relation to1A to2A-13, withFIG.2B-7showing a non-limiting, exemplary illustration of a fully operational isolation system with an isolated patient108.

As detailed, one or more embodiments of the present invention provide an isolation system that supports the protection of public health by ensuring that the first responders and medical staff are not exposed unnecessarily to infectious or contagious disease or other infectious matter while a patient is being transported to a final destination.

Further, the isolation system of the present invention protects vulnerable patients from the environment around them. Burn victims, patients recovering from cancer treatment, or others with severely compromised immune systems for example are particularly susceptible to airborne pathogens. The present invention may be used to fully isolate and protect such patients.

The present invention focuses on critical operational constraint to easily, rapidly, and assuredly encase patients within the isolation system to reduce or eliminate contaminations due to pathogens exposure.

Along with rapid isolation of the patient, another critical operational consideration is patient safety. The emplacement of the isolation system of the present invention does not cause undue physical discomfort for the patient, which would impede rapid and effective isolation.

Additionally, the ability to introduce medical grade oxygen into the isolation system and filtering out contaminated exhaust from the isolation system enhances the internal chamber environment for the patient while allowing the patient to be transported safely while isolated in the polyethylene membrane.

As indicated above, one of the key features of the isolation system of the present invention is that it is highly portable, one-time use and disposable. The medical grade oxygen, provided from a portable oxygen canister, may be flowing into the disposable containment polyethylene membrane in the range of 10 to 15 liters per minute during use, including transport, provided from a portable oxygen canister. The medical grade oxygen source can be facility piped-in oxygen or oxygen tanks. Nonetheless, the level of flow indicated above aids to ameliorate buildup of water vapor and carbon dioxide in the enclosure from exhalation of the patient.

Use of the isolation system of the present invention allows for management, control, and reduction of immediate threats to both patient and public health and safety. In addition, the isolation system in accordance with one or more embodiments of the present invention provide for a temporary isolation and containment of patients in scenarios such as, for example:Non-deferrable medical treatment of infected persons in a shelter or temporary medical facilityRelated medical facility services and suppliesMedical facilities and/or enhanced medical/hospital capacity (for treatment when existing facilities are reasonably forecasted to become overloaded in the near term and cannot accommodate patient capacity or to quarantine infected patients) thus protecting first responders and medical personnel.Medical sheltering (e.g. when existing facilities are reasonably forecasted to become overloaded soon and cannot accommodate needs)Sheltering conducted in accordance with standards and/or guidance approved by jurisdictional authorities such as, for example, HHS or CDC;Supports Non-congregate medical sheltering.Use of specialized medical equipment with isolation systemEmergency medical transportBiohazard waste disposal

FIGS.3A and3Bare non-limiting, exemplary illustrations of a fully assembled and functioning isolation system shown inFIG.1A to2B-7, but without an isolated patient sealed within in accordance with one or more embodiments of the present invention. Polyethylene membrane102may be filled with medical grade oxygen or air between 5 to 10 minutes while filter protective output plug120is removed.

As shown inFIGS.3A and3B, interior diameter124of an inflated polyethylene membrane102(about 80% inflated) is about 0.78 m, with an inflated length126of about 2.34 m providing a volume of about 1103 liters when inflated to about 80%. Polyethylene membrane102may be inflated for use from as low as 60% to fully inflated.

Below is a non-limiting, non-exhaustive, exemplary table of listing of some of the parameters of isolation system100, including non-limiting, exemplary nominal preferred values when isolation system100is inflated to about 80% and non-limiting, exemplary preferred operational range values:

TABLEApproximateNominal(or preferred)ApproximateVariableValuesRange ValuesInternal Positive pressure50 Pa50 to 150 Pa (testedto ~1000 Pa for burstwith no issues)Oxygen or air flow10 liters per10-30 liters perminuteminuteMembrane materialPolyethylene (IEST-Any clear plasticSTD 1246Dfilm compatibleLevel 100)with O2Membrane diameter0.78 meter.5 to 1 meterMembrane length2.34 meter1.5 (pediatric) to(inflated)2.5 meterMembrane thickness0.1 mm0.1 to 0.3 mmFirst or second port tube3.81 mm3 to 4 mm assection internal diameterneededFirst or second port tube5 cm4 to 6 cmsection lengthExhaust FilterHEPA (be & ve >HEPA of99.99%, flowcompatible sizeefficiency 32 lpm)

As further detailed below, the internal positive pressure is regulated by the pneumatic resistance to flow of the outlet hose barb282passage diameter and length. This pneumatic resistance to flow provides a nominal 50 Pa back pressure within membrane102. This pressure level of about 50 Pa is sufficient to support membrane102in an inflated state while minimizing leakage flow (if any).

Various tests conducted on one or more embodiments of isolation system100of the present invention positively confirm the following:The nominal oxygen or air inflow rate of about 10 liters per minute is sufficient to dilute Carbon Dioxide (CO2) and water vapor exhaled by the isolated patient, while limiting oxygen usage to preserve oxygen during the transport of the patient. Nominal oxygen or air inflow rate of about 10 liters per minute was determined based on a typical exhalation rates of an average individual. It should be noted that air may flow from a constant displacement air pump (which may require additional power source) at a rate of 20 to 30 liters per minute. Use of air is less preferred as it is the least effective (medically) because the patient does not receive oxygen enriched air. The flow rate of air is generally higher at about 20 to 30 liters per minute as compared with oxygen, which is at a flow rate of about 10 to 15 liters per minute. The higher flow rate of air is to lower the levels of exhaled carbon dioxide and water vapor that may accumulate inside membrane102. The water vapor removal in maintaining low humidity inside membrane102is important when using air (rather than oxygen) because the air is simply the ambient outside air and hence, is not dry.Temperature within membrane102of isolation system100stayed to within 5° C. of the surrounding environment after an hour.The relative humidity within membrane102of isolation system100continued to exhibit increasing transient behavior after an hour of isolation of a subject, well below an extreme level of 98% humidity.The subject within membrane102of isolation system100remained in a generally comfortable condition as exhibited by a generally slightly decreasing core body temperature during one-hour of isolation.The subject in isolation within membrane102of isolation system100was able to clearly and easily communicate with people in the immediate surroundings as demonstrated by verbally providing data to an outside observer.Extraction of patients from within membrane102of isolation system100(as detailed above) provided no observable aerosolization or expulsions of contaminants from membrane102of isolation system100.

In general, expanded (inflated) state of the polyethylene membrane102is stabilized (e.g., volume remains fairly constant) at non-limiting, exemplary internal positive pressure measurements of approximately 100 Pa, 74 Pa, and 50 Pa at non-limiting exemplary flow rates of about 1:5 liters per minute, 10 liters per minute, and 5 liters per minute; respectively. The structural integrity of the polyethylene membrane102and seal member106closed remain unchallenged at any of the above-mentioned exemplary flow ratings.

Polyethylene membrane102remains sufficiently inflated (at a non-limiting, exemplary volume of about 1100 liters at about 5 to 15 liters per minute with flow unimpeded through exhaust filter assembly118, but without polyethylene membrane102being excessively taut.

A flow of 10 to 15 liters per minute is a non-limiting, exemplary preferred setting for operation in accordance with one or more embodiments of the present invention. Polyethylene membrane102pressure is 50 Pa at the non-limiting, exemplary 10 liters per minute with the filter flow unimpeded. (Note; if the operator wishes polyethylene membrane102to be tauter, they can slightly impede the flow from exhaust filter assembly118by closing the outflow end122with filter protective output plug120.)

Polyethylene membrane102may be filled with medical grade oxygen or air at the correct differential pressure to the atmosphere to shape membrane102for operational use. High inflows of oxygen (>15 liters per minute) may be used to shape (inflate) the polyethylene membrane102enclosure, but then can be reduced to very moderate rates (about 10 to 15 liters per minute) for sustained containment of patient108without excess use of oxygen gas.

Polyethylene membrane102may be easily inflated and moderately taut at 10 liters per minute of inflow. At 10 liters per minute flow rate polyethylene membrane102pressure is approximately 50 Pa, and at 15 liters per minute pressure would be about 115 Pa.

It should be noted that polyethylene membrane102pressure at 15 liters per minute is less than about 115 Pa, which is still a very low pressure. Previously conducted pressure tests have resulted in isolation system100to withstand non-limiting, exemplary test pressures of about 1000 Pa, with isolation system100able to tolerate higher operating pressures with no issues.

Those skilled in the art would appreciate that because there is low pressure, there is no risk of systemic absorption of oxygen and, thus, the risk of pulmonary or central nervous system toxicity that can result from breathing high-pressure oxygen is not a problem. The increased oxygen helps oxidize disease-causing organisms. Oxygen toxicity does not occur using isolation system100because of shorten length of use (about 1 hour or so) within the polyethylene membrane102with patient108.

FIGS.4A to4Vare a non-limiting, exemplary illustration of the isolation system ofFIGS.1A to3B, with deflated (but unfurled) polyethylene membrane, including individual associated components in accordance with one or more embodiments of the present invention.

As illustrated inFIGS.1A to4V, membrane102is a transparent, flexible, portable, disposable sheet material comprised of polyethylene with an average thickness of about 0.102 mm.

The polyethylene membrane102is comprised of a thermally sealed sheet material with a single access opening104, forming an enlarged sheet material plastic (medical grade polyethylene) bag. Single access opening104has a length136oriented along a transverse axis130of the polyethylene membrane102. Membrane102meets or exceed requirements of IEST-STD 1246D Level 100 and is FDA approved.

Membrane102further includes thermally sealed lateral sides138and140that extend longitudinally from a thermally sealed end142to single access opening104, along a central longitudinal axis144of membrane102, with central longitudinal axis144defining overall length154of the polyethylene membrane102.

Thermally sealed lateral sides138and140diverge away from central longitudinal axis144near single access opening104at a divergent angle Ω, defining a wider span opening length136, with the span of length136of single access opening104greater than a span of a width150(defined along transverse axis130) of the polyethylene membrane102. Accordingly, width150of the polyethylene membrane102is substantially constant along central longitudinal axis144of the polyethylene membrane102starting from thermally sealed end142but increases near single access opening104. Wider access opening106facilitates for ease of entry of a patient108into isolation membrane102.

Thermally sealed lateral sides138and140may be identical, mirror images, and may include identical, longitudinally extending pleats146and148for facilitating an expansion of the polyethylene membrane102when inflated. It should be noted that the number of pleats may be increased to more than the two shown.

Pleats146and148have a transversely oriented separation distance152that decrease in span from thermally sealed end142, with both pleats146and148converging at single access open side104. Non-limiting example of separation distance152of pleats146and148at or near thermally seal end142is about 12.7 cm. Non-limiting example of length154of the polyethylene membrane102is about 259 cm, with width150of about 96.5 cm, with opening104having length136of about 123 cm.

Referring toFIGS.4A to4B-5, a linear seal member106is associated with single access opening104that when closed, seals off the internal chamber of the polyethylene membrane102. Seal member106is position parallel along a transverse axis130of the polyethylene membrane102. The orientation of seal member106along shorter transverse axis130is important in that potential of any leakage (if any) is minimized due to the shorter distance required to actually close-off the seal member102.

Seal member106may comprise of any mechanism that properly seals off the polyethylene membrane102. Proper sealing in accordance with one or more embodiments of the present invention may be defined as a seal that may withstand (i.e., maintain seal) at 100 Pa internal pressure. Non-limiting, non-exhaustive examples of mechanisms that may be used as a seal member may include most well-known sealing zippers, or others such Ziploc® bag type zippers, adhesive strip, etc. It would be possible but less desirable to use an adhesive strip instead of the zipper. Of course, use of zippers is preferred in that they may be opened and resealed while an adhesive strip would likely be single use.

The material used for seal member106(including all components that constitute isolation system100) must be compatible with the use of medical grade oxygen. In other words, the use of the combination of the medical grade oxygen and the material of the seal member106(and in fact, isolation system100) used should not result in off-gassing harmful chemicals that may be detrimental to patient108sealed within the polyethylene membrane102. Non-limiting example of a material that may be used for seal member106may comprise of polyethylene (the same as the polyethylene membrane102).

Seal member106may comprise of a heavy duty, single track zipper type (Ziploc® zipper type) sealer with colored (e.g., red) visual indicator160(FIG.4B-1) that shows a proper closure of seal member106. Seal member106may comprise one of a 3-bead sealer and 6 bead sealer, and is fully compatible for use with polyethylene and medical grade oxygen.

Seal member106may be applied to the polyethylene membrane102using well known processes, non-limiting example of which may include application of heat and an impulse, pressurized seal of seal member106to polyethylene membrane102, resulting in an integral, unitized construct. More particularly, seal member106may be thermally welded to membrane102.

Referring back toFIG.4A, first port110and second port112may be identical and form an integral unitized construct with the polyethylene membrane102. A first location of a first position of first port110in relation to thermally sealed lateral sides138and140and single access opening104is identical to a second location of a second position of second port112in relation to thermally sealed lateral sides138and140and thermally sealed end142.

The first location of the first position of first port110is defined by a first distance156oriented parallel central longitudinal axis144of the polyethylene membrane102from first port110to single access opening104, and a second distance158oriented parallel transverse axis130of the polyethylene membrane102from first port110to one of the thermally sealed lateral sides (138or140). The distance158from first port110to both thermally sealed either lateral sides138and140is identical and hence, first port110is positioned on central longitudinal axis144of the polyethylene membrane102.

The second location of the second position of second port112is defined by the same distance value156, from second port112to thermally sealed end142, and a second distance158oriented parallel transverse axis130of the polyethylene membrane102from second port112to one of the thermally sealed lateral sides (138or140).

Non-limiting examples of distance156may be about 61 cm and that of distance158about 48.3 cm. The critical and advantageous reasons for equal distances156and158for both first and second ports110and112is that, as detailed above, such an arrangement allows patient108to be moved into isolation within polyethylene membrane102head first or feet first, where in both instances, one of the first and second ports110or112will always be near the head of patient108(which will be used as the inflow or inlet port).

FIGS.4C to4Vare non-limiting, exemplary illustrations of first and second ports shown inFIGS.1A to4B-5in accordance with one or more embodiments of the present invention. As illustrated inFIGS.1A to4V, first and the second ports110and112are comprised of a first piece160and a second piece162for interlocking first piece160with the polyethylene membrane102.

As best illustrated inFIGS.4E,4G, and4H to4K, a non-limiting, exemplary method of installing first and second ports110and112is to poke a through-opening166(FIG.4H) on a mounting location168of the polyethylene membrane102, with the polyethylene membrane through-opening166having sufficient diameter to only allow projection206of first piece160to pass through.

Projection206of first piece160is inserted passed through opening166from an interior side170(FIG.4E) of mounting location168of the polyethylene membrane102. Thereafter, mounting opening180of second piece162is aligned and positioned over top edge182of barb section164(hose barb282) of projection206and moved (shown by arrows184) and pressed down to be interlocked with first piece160, with mounting location168of the polyethylene membrane102caught and securely fixed in between first and second pieces160and162. Second piece162interference-fits onto first piece160, thus fixing and sealing through-opening166of the polyethylene membrane102in between first and second pieces160and162without any thermal welding. It should be noted that inner diameter216(FIG.4H) of mounting opening180of second piece162is smaller than outer diameter218of interlocking projection210of projection206, resulting in interference fit interlocking of second piece162with first piece160.

First piece160has an annular construction with through opening (shown by arrow290inFIG.4G). Projection206(FIG.4H) includes a part of through-opening290protrudes perpendicular from a base176of first piece160.

Projection206includes an upper portion164that defines hose barb282of first piece160, a lower portion172that defines an interlocking projection210for interference fit of second piece162with first piece160, and a relief174for fixing second piece162in interlocked position in relation to first piece160.

Base176includes a top side with radially extending beveled lateral surface178, forming an annular frustum of right circular cone. Radial beveled lateral surface178facilitates to evenly spread-out mounting side168of the polyethylene membrane102around and away from the port, thus preventing potential kinking of the polyethylene membrane102when installing or mounting first or second ports110and112.

As best illustrated inFIGS.4P and4Q, radially extending beveled lateral surface178includes a top portion186with a vertical drop208that leads to a beveled portion188, and a bottom portion220that defines a horizontal portion190. The structure of the radially extending beveled lateral surface178is complementary to bottom side structure222(FIGS.4R and4U) of second piece162.

A bottom side194of first piece160includes circumferentially positioned protuberances196that function to substantially uniformly direct and distribute (more efficiently disburse) incoming medical grade oxygen or air shown by arrows198(FIGS.4E and4M) from opening290of first piece162into the internal chamber of the polyethylene membrane102and substantially uniformly direct and exhaust out exhaust air (shown by arrows202) from the internal chamber of the polyethylene membrane102and into opening290. Simply stated, protuberances196aid in providing laminar inflows198and laminar outflows202.

Given the flexible nature of the polyethylene membrane102, protuberances196also function to prevent the polyethylene membrane102to choke-off through-opening290when one of the first or second ports (110or112) is used as an outlet or exhaust port. That is, as exhaust is pushed out by incoming inflows198via through-opening290, the force may potentially flex the polyethylene membrane102where it may “cave-in” or “collect” towards through-opening290of the exhaust port, potentially causing a choked-flow effect.

As best shown inFIGS.4P and4Q, protuberances196have sufficient bulk to provide sufficient space214in-between to thereby block to prevent the polyethylene membrane102to potentially “cave-in” and vacuum seal with bottom flat circumferential edge212of first piece160, thus preventing blocking or choking off of outflows202from through-opening200. Accordingly, both ingress inflows198and egress outflows202remain substantially laminar, regardless of the movements of patient108within the polyethylene membrane102or when sealed-off patient108is transported.

It should be noted that it is only for the purposes of teaching and discussion that both incoming medical grade oxygen or air inflows198and exhaust outflows202are both shown simultaneously in relation to the same first piece160. As detailed above, obviously inflows will be through one port (110or112) and outflows through the other (112or110).

Referring back toFIG.4P, as was indicated above, the internal positive pressure PMem(i.e., the backpressure) within membrane102is regulated by the pneumatic resistance to the flow at the outlet interior passage (or tube portion)292, dictated by diameter294and length296. This pneumatic resistance to flow provides a nominal 50 Pa back pressure within membrane102(PMem). This pressure level of about 50 Pa is sufficient to support membrane102in an inflated state while minimizing leakage flow (if any). Accordingly, the outlet port (110or112) intrinsically functions as a passive pressure regulator.

The outlet port maintains an internal positive pressure PMemof the membrane102at a constant level for a given rate of flow of oxygen or air (e.g., liters per minute) to allow membrane102to remain in the expanded (inflated) state. Internal positive pressure PMemof membrane102is maintained as result of a back pressure generated by outlet port (110or112).

A pressure difference between interior or internal positive pressure PMemof membrane102and that of an outside ambient pressure PAmbis determined by a pressure drop ΔPOutletat outlet port110or112at a given flow rate, wherein:
PMem−PAmb=ΔPOutlet,

with the pressure drop ΔPOutletthrough the outlet port110/112generating the back pressure to establish interior positive pressure PMemof membrane102in accordance with:
PMem=ΔPOutlet+PAmb.

As detailed below, outlet port110or112is a solid non-varying object and therefore, the ΔPOutletwill be constant at a given flow rate. Further, outlet port functions an intrinsic passive pressure regulation that provides a back pressure (which is the PMem). Accordingly, for a given flow rate, PMemwill most likely also remain constant.

Further, interior positive pressure PMemis normalized to the outside ambient pressure PAmb. It should be noted that the differential pressure ΔPOutletwill remain the same regardless of the altitude within which the isolation system is used for a give flow rate. Of course, the higher the flow rate, the greater the internal positive pressure PMem.

The pressure differential ΔPOutletat the outlet port is a function of the interior geometry of the outlet port110or112and rate of flow of exhaust gas through the outlet port. The interior geometry of the outlet port is defined by an inner diameter294of interior passage (or tube portion)292of outlet port, a longitudinal axial length296of the interior passage (or tube portion)292of the outlet port, and an inner surface roughness of the interior passage (or tube portion)292of the outlet port.

The longitudinal axial length296of the interior passage (or tube portion)292of the outlet port is an elongated, hollow cylinder (with diameter294) of rigid plastic for transporting exhaust gases. The inner surface roughness coefficient of interior passage (or tube portion)292may be readily obtained from well known surface material charts/tables publications that include absolute roughness coefficients for various materials. In fact, it should be noted that all calculations related to fluid pressure drop (e.g., such as for ΔPOutlet) along pipe length of uniform diameter (e.g., such as interior passage (or tube portion)292) are simple basic fluid dynamics calculations that are very well known.

One or more embodiments of the present invention use a gas flow rate of about 32 liters per minute as part of the calculations for determining ΔPOutlet, which is the flow rate at which the HEPA filter228(further detailed below) of the present invention is certified. Filter228is certified to have the filtering efficiencies provided by the manufacturer for all flow rates up to 32 liters per minute. It should also be noted that any pressure drop across the HEPA filter228at a flow rate of 32 liters per minute is insignificant and in fact, negligible. In fact, it is a very small fraction of the overall pressure drop ΔPOutlet. The pressure drop ΔPOutletin Pascal across the outlet port110or112as a function of the flow rate of exhaust gas (liters per minute) through the interior passage (or tube portion)292of outlet port110or112is summarized in the chart ofFIG.4V.

As is well known to those skilled in the art, as the Reynolds number is increased (due to the Velocity V of the exhaust gas through the outlet port110or112), the exhaust gas flows through the outlet port move from the desired laminar flow conditions to a complete turbulent flow condition. The generated turbulent flow conditions within outlet port tube or pipe292would tend to hinder flow of exhaust gas, resulting in greater and greater back pressure (also known as “choked flow”) at the outlet port, which would result in greater and greater internal positive pressure PMem.

Maximum flow rate for the filter is 32 liters per minute as indicated above. Accordingly, even at such a high flow rate of 32 liters per minute, the generated internal pressure of the membrane PMem(of about 500 to 600 Pa) will not affect the structural integrity of membrane102nor the flow capacity of the filter.

As further shown inFIG.4V, at 10 liters per minute ΔPOutlet(which is also the backpressure or PMem) is about 50 Pa. Obviously, the greater the flow rate, the higher the internal pressure of the membrane PMem. It is preferred to maintain PMemas low as possible (e.g., 50 Pa) to simply maintain membrane102at its expanded inflated state, away from contacting the subject body fully isolated inside membrane102. Further, if there are any unintended openings (e.g., accidental puncture, for example, a small pin-hole sized opening at some section of membrane102), the leakage flow rate at the pin hole sized opening (if any) would be insignificant and in fact, negligible due to the very low internal positive pressure PMem(e.g., 50 Pa) of membrane102, thus membrane102would continue to encapsulate and isolate the subject inside even with a small (e.g., pin sized) puncture hole.

Accordingly, outlet port110or112indeed functions as a passive pressure regulator for a given flow rate. It should be noted that the flow rate throughout the system is the same. That is, the flow rate of gas at the inlet port, the membrane, and outlet port are all equal. Further, the pressure drop at the inlet port ΔPInletfrom the oxygen source into the member is not relevant for outlet port pressure drop calculations as the ΔPOutletis determined based on the flow rate at the outlet port and not pressure drop ΔPInlet.

It should be noted that modifying or changing the size or dimensions of the outlet port is possible so long as the isolation intent of the membrane is not compromised.

In summary, a pressure differential ΔPOutletgenerates a back pressure within membrane102that enables membrane102to remain in the expanded or inflated state at a pressure (PMem). The outlet port generates the back pressure that leads to a pressure drop through the outlet port ΔPOutlet, while maintaining the interior positive pressure of the membrane PMemconstant at a given flow rate. Further, low interior positive pressures of about 50 Pa are critical and advantageous in that such pressures continue to maintain membrane102in the expanded (inflated) state while allowing for application of unintentional or unintended external pressures. That is, even at its expanded (inflated) state, a person may easily compress or push into the membrane from outside and press it inward without much affect to the overall operation of the membrane. In other words, the low pressure PMemdoes not expand the membrane to be too taut to a point where if it comes into contact with a sharp object it may puncture (similar to puncturing a balloon with a pin).

Use of low interior positive pressures PMemis further critical and advantageous because low interior positive pressures PMemreduce a potential for leakage of exhaust gas from within the membrane. In fact, the interior positive pressures PMemat 50 Pa is so low that even if there is a leak, the leaked exhaust gas would be insignificant.

FIGS.5A-1to51-3are non-limiting, exemplary illustrations of an exhaust filter assembly shown inFIGS.1A to4Vin accordance with one or more embodiments of the present invention. As illustrated inFIGS.5A-1to51-3, exhaust filter assembly118(fully compatible with use with medical grade oxygen) is comprised of a well-known filter sub-assembly224that includes a well-known filter housing226with a well-known filter228. It is preferred if filter228is comprised of a Hight-Efficiency Particulate Air (HEPA) filter and more particularly, any HEPA filter228greater than HEPA class E12/H12 (based on European standard). In fact, present invention most preferably uses HEPA class U15 HEPA filters. In particular, exhaust gas filter assembly118may be a high flow, low pressure differential HEPA filter, certified to remove 99.99% of viral and 99.999% bacterial contamination.

Exhaust filter assembly118further includes a filter connector assembly230to connect exhaust filter subassembly224to the polyethylene membrane102, and also includes filter protective output plug120.

Filter connector assembly230is comprised of a medical grade oxygen rated outflow tubing128(identical to inflow tube114), including a barb232that receives down-stream end234of the medical grade oxygen rated outflow tubing128. Further included is an adapter-cap236that allows mounting and sealing of barb232to filter subassembly224.

Barb232is secured with adapter-cap236by a washer238and a nut240via a top opening242of adapter-cap236. Adapter-cap236is an annular piece with a smaller diameter top opening242to receive threaded end244of barb232, and a larger diameter bottom opening246for mounting onto and over upstream end248of filter subassembly224. As best illustrated inFIGS.41-1to41-4, filter assembly plug120is configured to plug into downstream end250of filter subassembly224.

It should be noted that filter228does not impede the flow rate of exhaust gas via the outlet port and thus, the rate of outflow of exhaust gas via the outlet port is equal to the rate of inflow of oxygen via the inlet port, while the internal positive pressure of membrane102remains constant for a given flow rate.

Although the invention has been described in considerable detail in language specific to structural features (e.g., measurements, etc.) and or method acts, it is to be understood that the invention defined in the appended claims (if any) is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as exemplary preferred forms of implementing the claimed invention. Stated otherwise, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting. Further, the specification is not confined to the disclosed embodiments. Therefore, while exemplary illustrative embodiments of the invention have been described, numerous variations and alternative embodiments will occur to those skilled in the art. For example, Because the isolation system is intended for operation with either medical grade oxygen or compressed air, all components, including the polyethylene membrane, and the exhaust filter assembly must be medical grade oxygen compatible. Additionally, a one-to-one correspondence between isolation system100and a source of oxygen, air, or air enriched with oxygen should not be assumed. For example, a single canister of oxygen may be used to simultaneously supply oxygen to multiple separate isolation systems100using any well-known oxygen flowmeter tee-branch or other well known adapter connectors. Such variations and alternate embodiments are contemplated, and can be made without departing from the spirit and scope of the invention.

It should further be noted that throughout the entire disclosure, the labels such as left, right, front, back, top, inside, outside, bottom, forward, reverse, clockwise, counter clockwise, up, down, or other similar terms such as upper, lower, aft, fore, vertical, horizontal, lateral, oblique, proximal, distal, parallel, perpendicular, transverse, longitudinal, etc. have been used for convenience purposes only and are not intended to imply any particular fixed direction, orientation, or position. Instead, they are used to reflect relative locations/positions and/or directions/orientations between various portions of an object.

In addition, reference to “first,” “second,” “third,” and etc. members throughout the disclosure (and in particular, claims) is not used to show a serial or numerical limitation but instead is used to distinguish or identify the various members of the group.

Further the terms “a” and “an” throughout the disclosure (and in particular, claims) do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.

The use of the phrases “and or,” “and/or” throughout the specification (if any used) indicate an inclusive “or” where for example, A and or B should be interpreted as “A,” “B,” or both “A and B.”

In addition, any element in a claim that does not explicitly state “means for” performing a specified function, or “step for” performing a specific function, is not to be interpreted as a “means” or “step” clause as specified in 35 U.S.C. Section 112, Paragraph 6. In particular, the use of “step of,” “act of,” “operation of,” or “operational act of” in the claims herein is not intended to invoke the provisions of 35 U.S.C. 112, Paragraph 6.