NOTE: End date changed to 9/30/2019 per HRP Technology Pipeline spreadsheet sent by B. Corbin (Ed., 9/9/14)

NOTE: Title change to Oxygen Delivery System (previously Medical Oxygen Fire Safety), per M. Covington/JSC via S. Watkins/ExMC/JSC (Ed., 9/23/13)

NOTE: End date changed to 12/31/17 per PI information (Ed., 7/26/13)

Current spaceflight oxygen delivery systems deliver pure oxygen to the crewmember from high pressure oxygen tanks, which results in a gradual increase in cabin oxygen levels and a localized area of increased oxygen concentration in the vicinity of the crewmember, posing an increased fire hazard.

The Oxygen Concentrator Module (OCM) project is tasked with developing an oxygen delivery system with variable oxygen capability that minimizes localized oxygen build-up and meets the commercial crew vehicle evacuation requirements.

Work focuses on the development of a supplemental oxygen delivery system for crewmembers that pulls oxygen out of the ambient environment instead of using compressed oxygen. This provides better resource optimization and reduces fire hazard by preventing the formation of localized pockets of increased oxygen concentration within the vehicle. The system will provide oxygen support in a closed cabin environment where the atmosphere may be at a reduced pressure and elevated oxygen percentage (compared to terrestrial standard atmosphere composition and pressure).

Future space missions will take astronauts beyond Earth’s orbit. These exploration missions may be long in duration (e.g., 36 months) and will have limited resources. It is vital that each piece of equipment serve as many functions as possible, with built in redundancy. A modular oxygen concentrator that uses the ambient cabin air can serve a number of functions (medical emergency, pre-breathing, atmospheric contamination, or leak) without taxing other spacecraft systems to compensate for an increase in ambient oxygen. This improves mission safety by not exacerbating fire risk, and minimizing system interdependencies.

This gap aligns well with the International Space Station (ISS) Health Maintenance System (HMS) because HMS currently has no oxygen delivery system that can meet commercial crew vehicle evacuation requirements. Concentrating oxygen from cabin air eliminates the up mass associated with oxygen tanks and reduces fire hazard, as it prevents the formation of localized pockets of increased oxygen levels within the vehicle.

An oxygen concentrator for crew medical support is considered vital to provide an ill crewmember with ventilation with oxygen. Providing a method of oxygen therapy that uses cabin air keeps the oxygen levels stable and avoids Environmental Control and Life Support System (ECLSS) intervention required to maintain the cabin oxygen levels.

The medical conditions requiring oxygen supplementation include: Altitude sickness, Anaphylaxis, Burns, Choking/obstructed airway, Cough –URI, bronchitis, pneumonia, inhalation, De Novo cardiac arrhythmia, Decompression sickness, Headache (CO2, SAS, other), Infection – sepsis, Medication overdose/misuse, Neck injury, Radiation sickness, Seizure, Smoke inhalation, and Toxic exposure.

The final flight system for an oxygen delivery system needs to be Food & Drug Administration (FDA) clearable device and should be designed to minimize mass, volume, and power. A demonstration unit for the International Space Station (ISS) should verify the technology and provide oxygen capability for ISS.

There are two US oxygen delivery systems currently used onboard the ISS--the Respiratory Support Pack (RSP) and the Portable Breathing Apparatus (PBA). The RSP uses the ISS 120 psi oxygen lines and delivers pure oxygen up to 12 L/min. The RSP is for medical O2 usage. The PBA consists of a non-refillable portable oxygen bottle that provides 15 minutes of oxygen and also includes a 30 foot hose to attach to the ISS oxygen lines for long term oxygen supply. The PBAs are distributed throughout the ISS, and a few are available in each module or node. Both the PBAs and the RSP can obtain their oxygen supply from high pressure tanks located on the ISS. The PBAs also attached to the ISS oxygen line for use during the pre-Extravehicular Activity (EVA) pre-breathe protocol (a method of decreasing the body’s nitrogen load and the risk of decompression sickness). The PBAs are also used for emergency oxygen usage (e.g., in a tox hazard or fire situation). An alternative to the US oxygen mask is the Russian isolating gas mask that can be used during fire or atmospheric contamination events. It provides 70 minutes of oxygen, but has been reported to be bulky, hot, and uncomfortable to wear for long periods of time. The main challenge with the current systems is that when using either the RSP or PBAs, the cabin oxygen concentration is elevated which increases the fire hazard. Modeling results have shown that when a patient is receiving oxygen, the oxygen concentration aboard the ISS rises very slowly secondary to the large volume and good mixing due to ventilation. In a much smaller spacecraft, the oxygen concentration increases much more rapidly and the risk of fire increases accordingly. Even in the ISS well-mixed scenario there is a pocket of elevated oxygen around the astronaut’s head and chest area that creates a high risk situation. If an ignition source is introduced into this area, the resulting fire can rapidly spread through the oxygen-saturated clothing and hair as well as to other astronauts who may be treating the patient. For exploration atmospheres, the ambient atmosphere may be at elevated oxygen and reduced pressure as the norm, increasing the flammability of materials in general.

Ignition hazards for medical operations during future spaceflights may be similar to those encountered in a typical operating room: defibrillators, laser beams, and fiber optic light sources are already available on the ISS. These tools can cause sparks when the energy impacts a metallic surface. The sparks or even the glowing embers of charring materials can provide enough initial heat to ignite some fuels, especially in oxygen enriched atmospheres. Hot electrical components in an oxygen enriched environment can be a source of ignition also. The ignition hazard may exist for a few minutes after deactivation of the source. Heat transfer is different in microgravity. Hot surfaces are hotter in the absence of gravity, and cooling times are longer.

A concept of operations document was baselined [1]. The ConOps provides a description of the Medical Oxygen Patient Interface (MOPI) in an easily understood format of narrative and illustration. The ConOps is a system level conceptual response to the requirements stated in the Engineering Requirements Document (ERD). It provides a description of the primary system functions, and concepts for integration, deployment, operations, and support. The purpose of this ConOps is to describe the system characteristics of the proposed Medical Oxygen Patient Interface from the user’s viewpoint. As the MOPI evolves, the ConOps will be updated to reflect the current design and planning.

The two year Phase II SBIR for a Vacuum Swing Adsorption (VSA) system that utilizes this 4 component parallel architecture was completed in December, 2017, and the final report received. TDA's VSA system uses a modified version of the lithium exchanged low silica X zeolite (Li-LSX), a state-of-the-art air separation sorbent extensively used in commercial Portable Oxygen Concentrators (POCs) to enhance the N2 adsorption capacity. The TDA, Inc. SBIR Phase II delivered four oxygen generator units. The units use ambient vehicle cabin air as the feed and delivers high purity oxygen. A laptop with control software to remotely operate the prototype was also delivered.

The four units will be tested in the Spacecraft Exploration Atmospheres Test Lab at NASA Glenn Research Center (Bldg. 77- Rm.151) to evaluate the oxygen concentrator prototypes. The area of the lab used for the testing includes the test chamber, a vacuum exhaust system, a gas supply rack, chiller, power supplies, and a data acquisition system.

[1] Calaway K. Zin Technologies, Inc. "Medical Oxygen Patient Interface (MOPI) Concept of Operations Document." NASA Concept of Operations document OCM-CONOPS-002 Internal document, July 2017.

NOTE: End date changed to 9/30/2019 per HRP Technology Pipeline spreadsheet sent by B. Corbin (Ed., 9/9/14)

NOTE: Title change to Oxygen Delivery System (previously Medical Oxygen Fire Safety), per M. Covington/JSC via S. Watkins/ExMC/JSC (Ed., 9/23/13)

NOTE: End date changed to 12/31/17 per PI information (Ed., 7/26/13)

ExMC Gap 4.04: We do not have the capability to deliver supplemental oxygen to crewmembers while minimizing local and cabin oxygen build-up during exploration missions.

Current spaceflight oxygen delivery systems deliver pure oxygen to the crewmember from high pressure oxygen tanks, which results in a gradual increase in cabin oxygen levels and a localized area of increased oxygen concentration in the vicinity of the crewmember, posing an increased fire hazard.

The Oxygen Concentrator Module (OCM) project is tasked with developing an oxygen delivery system with variable oxygen capability that minimizes localized oxygen build-up and meets the commercial crew vehicle evacuation requirements.

Work under this gap focuses on the development of a supplemental oxygen delivery system for crewmembers that pulls oxygen out of the ambient environment instead of using compressed oxygen. This provides better resource optimization and reduces fire hazard by preventing the formation of localized pockets of increased oxygen concentration within the vehicle. The system will provide oxygen support in a closed cabin environment where the atmosphere may be at a reduced pressure and elevated oxygen percentage (compared to terrestrial standard atmosphere composition and pressure). Reference ( http://humanresearchroadmap.nasa.gov/Gaps/?i=412 ) for additional information on this gap.

Future space missions will take astronauts beyond Earth’s orbit. These exploration missions may be long in duration (e.g., 36 months) and will have limited resources. It is vital that each piece of equipment serve as many functions as possible, with built in redundancy. A modular oxygen concentrator that uses the ambient cabin air can serve a number of functions (medical emergency, pre-breathing, atmospheric contamination, or leak) without taxing other spacecraft systems to compensate for an increase in ambient oxygen. This improves mission safety by not exacerbating fire risk, and minimizing system interdependencies.

This gap aligns well with the International Space Station (ISS) Health Maintenance System (HMS) because HMS currently has no oxygen delivery system that can meet commercial crew vehicle evacuation requirements. Concentrating oxygen from cabin air eliminates the up mass associated with oxygen tanks and reduces fire hazard, as it prevents the formation of localized pockets of increased oxygen levels within the vehicle.

An oxygen concentrator for crew medical support is considered vital to provide an ill crewmember with ventilation with oxygen. Providing a method of oxygen therapy that uses cabin air keeps the oxygen levels stable and avoids Environmental Control and Life Support System (ECLSS) intervention required to maintain the cabin oxygen levels.

The medical conditions requiring oxygen supplementation include: Altitude sickness, Anaphylaxis, Burns, Choking/obstructed airway, Cough –URI, bronchitis, pneumonia, inhalation, De Novo cardiac arrhythmia, Decompression sickness, Headache (CO2, SAS, other), Infection – sepsis, Medication overdose/misuse, Neck injury, Radiation sickness, Seizure, Smoke inhalation, and Toxic exposure.

The final flight system for an oxygen delivery system needs to be Food & Drug Administration (FDA) clearable device and should be designed to minimize mass, volume, and power. A demonstration unit for the International Space Station (ISS) should verify the technology and provide oxygen capability for ISS.

There are two US oxygen delivery systems currently used onboard the ISS--the Respiratory Support Pack (RSP) and the Portable Breathing Apparatus (PBA). The RSP uses the ISS 120 psi oxygen lines and delivers pure oxygen up to 12 L/min. The RSP is for medical O2 usage. The PBA consists of a non-refillable portable oxygen bottle that provides 15 minutes of oxygen and also includes a 30 foot hose to attach to the ISS oxygen lines for long term oxygen supply. The PBAs are distributed throughout the ISS, and a few are available in each module or node. Both the PBAs and the RSP can obtain their oxygen supply from high pressure tanks located on the ISS. The PBAs also attached to the ISS oxygen line for use during the pre-Extravehicular Activity (EVA) pre-breathe protocol (a method of decreasing the body’s nitrogen load and the risk of decompression sickness). The PBAs are also used for emergency oxygen usage (e.g., in a tox hazard or fire situation). An alternative to the US oxygen mask is the Russian isolating gas mask that can be used during fire or atmospheric contamination events. It provides 70 minutes of oxygen, but has been reported to be bulky, hot, and uncomfortable to wear for long periods of time. The main challenge with the current systems is that when using either the RSP or PBAs, the cabin oxygen concentration is elevated which increases the fire hazard. Modeling results have shown that when a patient is receiving oxygen, the oxygen concentration aboard the ISS rises very slowly secondary to the large volume and good mixing due to ventilation. In a much smaller spacecraft, the oxygen concentration increases much more rapidly and the risk of fire increases accordingly. Even in the ISS well-mixed scenario there is a pocket of elevated oxygen around the astronaut’s head and chest area that creates a high risk situation. If an ignition source is introduced into this area, the resulting fire can rapidly spread through the oxygen-saturated clothing and hair as well as to other astronauts who may be treating the patient. For exploration atmospheres, the ambient atmosphere may be at elevated oxygen and reduced pressure as the norm, increasing the flammability of materials in general.

Ignition hazards for medical operations during future spaceflights may be similar to those encountered in a typical operating room: defibrillators, laser beams, and fiber optic light sources are already available on the ISS. These tools can cause sparks when the energy impacts a metallic surface. The sparks or even the glowing embers of charring materials can provide enough initial heat to ignite some fuels, especially in oxygen enriched atmospheres. Hot electrical components in an oxygen enriched environment can be a source of ignition also. The ignition hazard may exist for a few minutes after deactivation of the source. Heat transfer is different in microgravity. Hot surfaces are hotter in the absence of gravity, and cooling times are longer.

ExMC can provide risk mitigation by verifying the performance of existing commercially available OCM devices on station.

NOTE: End date changed to 9/30/2019 per HRP Technology Pipeline spreadsheet sent by B. Corbin (Ed., 9/9/14)

NOTE: Title change to Oxygen Delivery System (previously Medical Oxygen Fire Safety), per M. Covington/JSC via S. Watkins/ExMC/JSC (Ed., 9/23/13)

NOTE: End date changed to 12/31/17 per PI information (Ed., 7/26/13)

ExMC Gap 4.04: We do not have the capability to deliver supplemental oxygen to crewmembers while minimizing local and cabin oxygen build-up during exploration missions.

Current spaceflight oxygen delivery systems deliver pure oxygen to the crewmember from high pressure oxygen tanks, which results in a gradual increase in cabin oxygen levels and a localized area of increased oxygen concentration in the vicinity of the crewmember, posing an increased fire hazard.

The Oxygen Concentrator Module (OCM) project is tasked with developing an oxygen delivery system with variable oxygen capability that minimizes localized oxygen build-up and meets the commercial crew vehicle evacuation requirements.

Work under this gap focuses on the development of a supplemental oxygen delivery system for crewmembers that pulls oxygen out of the ambient environment instead of using compressed oxygen. This provides better resource optimization and reduces fire hazard by preventing the formation of localized pockets of increased oxygen concentration within the vehicle. The system will provide oxygen support in a closed cabin environment where the atmosphere may be at a reduced pressure and elevated oxygen percentage (compared to terrestrial standard atmosphere composition and pressure). Reference ( http://humanresearchroadmap.nasa.gov/Gaps/?i=412 ) for additional information on this gap.

Future space missions will take astronauts beyond Earth’s orbit. These exploration missions may be long in duration (e.g., 36 months) and will have limited resources. It is vital that each piece of equipment serve as many functions as possible, with built in redundancy. A modular oxygen concentrator that uses the ambient cabin air can serve a number of functions (medical emergency, pre-breathing, atmospheric contamination, or leak) without taxing other spacecraft systems to compensate for an increase in ambient oxygen. This improves mission safety by not exacerbating fire risk, and minimizing system interdependencies.

This gap aligns well with the International Space Station (ISS) Health Maintenance System (HMS) because HMS currently has no oxygen delivery system that can meet commercial crew vehicle evacuation requirements. Concentrating oxygen from cabin air eliminates the up mass associated with oxygen tanks and reduces fire hazard, as it prevents the formation of localized pockets of increased oxygen levels within the vehicle.

An oxygen concentrator for crew medical support is considered vital to provide an ill crewmember with ventilation with oxygen. Providing a method of oxygen therapy that uses cabin air keeps the oxygen levels stable and avoids Environmental Control and Life Support System (ECLSS) intervention required to maintain the cabin oxygen levels.

The medical conditions requiring oxygen supplementation include: Altitude sickness, Anaphylaxis, Burns, Choking/obstructed airway, Cough–URI (upper respiratory infection), bronchitis, pneumonia, inhalation, De Novo cardiac arrhythmia, Decompression sickness, Headache (CO2, SAS, other), Infection – sepsis, Medication overdose/misuse, Neck injury, Radiation sickness, Seizure, Smoke inhalation, and Toxic exposure.

The final flight system for an oxygen delivery system needs to be Food & Drug Administration (FDA) clearable device and should be designed to minimize mass, volume, and power. A demonstration unit for the International Space Station (ISS) should verify the technology and provide oxygen capability for ISS.

There are two US oxygen delivery systems currently used onboard the ISS--the Respiratory Support Pack (RSP) and the Portable Breathing Apparatus (PBA). The RSP uses the ISS 120 psi oxygen lines and delivers pure oxygen up to 12 L/min. The RSP is for medical O2 usage. The PBA consists of a non-refillable portable oxygen bottle that provides 15 minutes of oxygen and also includes a 30 foot hose to attach to the ISS oxygen lines for long term oxygen supply. The PBAs are distributed throughout the ISS, and a few are available in each module or node. Both the PBAs and the RSP can obtain their oxygen supply from high pressure tanks located on the ISS. The PBAs also attached to the ISS oxygen line for use during the pre-Extravehicular Activity (EVA) pre-breathe protocol (a method of decreasing the body’s nitrogen load and the risk of decompression sickness). The PBAs are also used for emergency oxygen usage (e.g., in a tox hazard or fire situation). An alternative to the US oxygen mask is the Russian isolating gas mask that can be used during fire or atmospheric contamination events. It provides 70 minutes of oxygen, but has been reported to be bulky, hot, and uncomfortable to wear for long periods of time. The main challenge with the current systems is that when using either the RSP or PBAs, the cabin oxygen concentration is elevated which increases the fire hazard. Modeling results have shown that when a patient is receiving oxygen, the oxygen concentration aboard the ISS rises very slowly secondary to the large volume and good mixing due to ventilation. In a much smaller spacecraft, the oxygen concentration increases much more rapidly and the risk of fire increases accordingly. Even in the ISS well-mixed scenario there is a pocket of elevated oxygen around the astronaut’s head and chest area that creates a high risk situation. If an ignition source is introduced into this area, the resulting fire can rapidly spread through the oxygen-saturated clothing and hair as well as to other astronauts who may be treating the patient. For exploration atmospheres, the ambient atmosphere may be at elevated oxygen and reduced pressure as the norm, increasing the flammability of materials in general.

Ignition hazards for medical operations during future spaceflights may be similar to those encountered in a typical operating room: defibrillators, laser beams, and fiber optic light sources are already available on the ISS. These tools can cause sparks when the energy impacts a metallic surface. The sparks or even the glowing embers of charring materials can provide enough initial heat to ignite some fuels, especially in oxygen enriched atmospheres. Hot electrical components in an oxygen enriched environment can be a source of ignition also. The ignition hazard may exist for a few minutes after deactivation of the source. Heat transfer is different in microgravity. Hot surfaces are hotter in the absence of gravity, and cooling times are longer.

A very ill crewmember requires a significant flow of oxygen, up to 15 LPM, but lower flow rates can be adequate for less ill crewmembers or as respiratory supply of healthy crew.

To address these multiple flow ranges, a parallel architecture approach was applied this year to the technology development. In this system design, a set of 4 redundant lower flow concentrators (4 LPM each) is envisioned that could be used separately as needed or combined for the high flow need. The lower flow modules can be run off batteries for a reasonable period of time, or plugged in if the crew is relatively stationary.

The oxygen concentrator could be used in a portable mode at 4 LPM as an option for pre-breathing protocol by the crew in preparation for Extravehicular Activities (EVA). The portability of the system could allow the astronaut the ability to move around and perform other activities while completing the pre-breathing protocol. This may be needed during the long transit to Mars, where the spacecraft cabin is still normal atmospheric air, for example.

The portable, distributed oxygen concentrator could also be used to protect healthy crewmembers if there is an atmospheric contamination event such as a toxic spill or a fire, to avoid toxic gas or smoke inhalation. A replaceable inlet filter on the unit would remove toxic gases from the oxygen delivery stream, allowing the user to breathe in the enriched ambient oxygen free of smoke, dust, or other contaminates. The concentrator could also be used to provide an adequate partial pressure of oxygen in the event of an emergency leak, allowing the crew to find and stop the leak while ensuring an adequate oxygen supply as the spacecraft pressure drops.

In 2015, a two year Phase II SBIR (Small Business Innovation Research) was awarded for a Vacuum Swing Adsorption – VSA system that will utilize this parallel architecture. The TDA, Inc. SBIR Phase II is continuing the development of an oxygen generator based on a vacuum swing adsorption (VSA) to produce concentrated medical oxygen. In Phase I they designed and built and evaluated the performance of the sorbent in a breadboard bench-scale prototype. The unit uses ambient vehicle cabin air as the feed and delivers high purity oxygen. TDA's VSA system uses a modified version of the lithium exchanged low silica X zeolite (Li-LSX), a state-of-the-art air separation sorbent extensively used in commercial Portable Oxygen Concentrators (POCs), to enhance the N2 adsorption capacity. In Phase II, they will build and deliver two units so that the units can be tested individually, or in parallel.

NOTE: End date changed to 9/30/2019 per HRP Technology Pipeline spreadsheet sent by B. Corbin (Ed., 9/9/14)

NOTE: Title change to Oxygen Delivery System (previously Medical Oxygen Fire Safety), per M. Covington/JSC via S. Watkins/ExMC/JSC (Ed., 9/23/13)

NOTE: End date changed to 12/31/17 per PI information (Ed., 7/26/13)

There are many medical conditions listed on the Space Medicine Exploration Medicine Conditions List (SMEMCL) that involve either treatment with supplemental oxygen or full ventilator support. Medical conditions that the Oxygen Concentrator Module must address per decision of NASA’s Exploration Medical Capabilities Advisory Board include those which may require oxygen or ventilation use, including: smoke inhalation, sepsis, angina/myocardial infarction, hypovolemic shock, medication overdose, decompression sickness, stroke, head injury, choking/obstructed airway, chest injury, sudden cardiac arrest, altitude sickness, seizures, cardiogenic shock, radiation syndrome, neurogenic shock, toxic exposure to ammonia, and anaphylaxis.

There are two US oxygen delivery systems currently used onboard the International Space Station (ISS)--the Respiratory Support Pack (RSP) and the Portable Breathing Apparatus (PBA). The RSP uses the ISS 120 psi oxygen lines and delivers pure oxygen up to 12 L/min. The RSP is for medical O2 usage. The PBA consists of a non-refillable portable oxygen bottle that provides 15 minutes of oxygen and also includes a 30 foot hose to attach to the ISS oxygen lines for long term oxygen supply. The PBAs are distributed throughout the ISS, and a few are available in each module or node. Both the PBAs and the RSP can obtain their oxygen supply from high pressure tanks located on the ISS. The PBAs also attached to the ISS oxygen line for use during the pre-Extravehicular Activity (EVA) pre-breathe protocol (a method of decreasing the body’s nitrogen load and the risk of decompression sickness). The PBAs are also used for emergency oxygen usage (e.g., in a tox hazard or fire situation). An alternative to the US oxygen mask is the Russian isolating gas mask that can be used during fire or atmospheric contamination events. It provides 70 minutes of oxygen, but has been reported to be bulky, hot, and uncomfortable to wear for long periods of time. The main challenge with the current systems is that when using either the RSP or PBAs, the cabin oxygen concentration is elevated which increases the fire hazard. Modeling results have shown that when a patient is receiving oxygen, the oxygen concentration aboard the ISS rises very slowly secondary to the large volume and good mixing due to ventilation. In a much smaller spacecraft, the oxygen concentration increases much more rapidly and the risk of fire increases accordingly. Even in the ISS well-mixed scenario there is a pocket of elevated oxygen around the astronaut’s head and chest area that creates a high risk situation. If an ignition source is introduced into this area, the resulting fire can rapidly spread through the oxygen-saturated clothing and hair as well as to other astronauts who may be treating the patient. For exploration atmospheres, the ambient atmosphere may be at elevated oxygen and reduced pressure as the norm, increasing the flammability of materials in general.

Ignition hazards for medical operations during future space flights may be similar to those encountered in a typical operating room: defibrillators, laser beams, and fiber optic light sources are already available on the ISS. These tools can cause sparks when the energy impacts a metallic surface. The sparks or even the glowing embers of charring materials can provide enough initial heat to ignite some fuels, especially in oxygen enriched atmospheres. Hot electrical components in an oxygen enriched environment can be a source of ignition also. The ignition hazard may exist for a few minutes after deactivation of the source. Heat transfer is different in microgravity. Hot surfaces are hotter in the absence of gravity, and cooling times are longer.

The Exploration Atmospheres Lab includes the test chamber, a vacuum exhaust system, a gas supply rack, chiller, power supplies, and data acquisition system. The test chamber is a 60 cm x 60 cm x 60 cm vacuum chamber with a cold plate at the floor level. A chiller is used to provide temperature-conditioned water to the cold plate in the bottom of the chamber. This is used primarily for heat rejection to maintain the chamber temperature at near-ambient conditions. Saturated salts are used to control the initial humidity in the chamber. A vacuum system is used to evacuate the chamber so it can be filled with the desired gas mixture. If the concentrator cannot withstand a hard vacuum, the chamber is partially evacuated and filled with the desired gas mixture repeatedly to obtain the desired ambient oxygen concentration and total pressure.

The chamber is filled from the bottle rack, which contains different O2-N2 blends of 21% O2, 30% O2, and 34% O2. In addition, a combustion products ‘air’ blend is present that contains 1% CO2 and 55 ppm of CO. Additional bottles of 95% O2 and 100% N2 are used to calibrate and purge the oxygen sensor before and after each test, respectively. The oxygen concentrator is placed in the test chamber, draws in the ambient atmosphere from the chamber, and separates the gases to a waste stream that is predominantly nitrogen, and a product stream which is predominantly oxygen. Each of the three flow streams is measured for pressure, flow rate, temperature, humidity, and the oxygen concentration of the product stream is also measured. In addition, the voltage and current draw of the prototype was measured, and CO and CO2 sensors were used in some tests that used a gas mixture with these contaminants present.

At the end of the testing, a report was finished comparing the Ritter PSA Prototype to the Lynntech Electrochemical Prototype we received and tested in 2012. This report serves as our annual report this year. Both prototypes were tested in the same lab, and were judged against the current flight oxygen concentrator requirements. Both prototypes met some of the requirements, but not all of them, since these are prototype units and not high TRL (technology readiness level). The PSA prototype successfully met 12 of 23 requirements, and the electrochemical prototype met 8 of 23 requirements. Based on this evaluation, the PSA technology had a clear technical advantage over the electrochemical technology.

In addition, in 2014, two Phase I SBIRs (Small Business Innovation Research) were awarded pursuing two different technologies (Vacuum Swing Adsorption - VSA, and a different electrochemical design). The TDA, Inc. SBIR Phase I developed an oxygen generator based on a vacuum swing adsorption (VSA) to produce concentrated medical oxygen. They designed and built and evaluated the performance of the sorbent in a breadboard bench-scale prototype. The unit uses ambient vehicle cabin air as the feed and delivers high purity oxygen. TDA's VSA system uses a modified version of the lithium exchanged low silica X zeolite (Li-LSX), a state-of-the-art air separation sorbent extensively used in commercial Portable Oxygen Concentrators (POCs) to enhance the N2 adsorption capacity. The Reactive Innovations SBIR Phase I developed a modular electrochemical subscale concentrator and performed a preliminary design based on the performance of their arrangement of modular separation units. They demonstrated that modular separation units could be manufactured that separated oxygen from exploration atmospheres to produce pure oxygen. The modular separation units were compact, light-weight, and low cost serving both NASA needs and Reactive Innovation’s commercial pursuits.

Lastly, a technology development plan was updated this year, and the Oxygen Concentrator Module (OCM) project has had extensive discussions with Johnson Space Center (JSC) and NASA Headquarters (HQ) personnel regarding synergy with EVA high pressure, high purity oxygen requirements for exploration missions. We also identified oxygen needs for pre-breathing prior to EVA and in the event of a toxic spill or fire.

NOTE: End date changed to 9/30/2019 per HRP Technology Pipeline spreadsheet sent by B. Corbin (Ed., 9/9/14)

NOTE: Title change to Oxygen Delivery System (previously Medical Oxygen Fire Safety), per M. Covington/JSC via S. Watkins/ExMC/JSC (Ed., 9/23/13)

NOTE: End date changed to 12/31/17 per PI information (Ed., 7/26/13)

There are many medical conditions listed on the Space Medicine Exploration Medicine Conditions List (SMEMCL) that involve either treatment with supplemental oxygen or full ventilator support. Medical conditions that the Oxygen Concentrator Module must address per decision of NASA’s Exploration Medical Capabilities Advisory Board include those which may require oxygen or ventilation use including: smoke inhalation, sepsis, angina/myocardial infarction, hypovolemic shock, medication overdose, decompression sickness, stroke, head injury, choking/obstructed airway, chest injury, sudden cardiac arrest, altitude sickness, seizures, cardiogenic shock, radiation syndrome, neurogenic shock, toxic exposure to ammonia, and anaphylaxis.

There are two US oxygen delivery systems currently used onboard the International Space Station (ISS); the Respiratory Support Pack (RSP) and the Portable Breathing Apparatus (PBA). The RSP uses the ISS 120 psi oxygen lines and delivers pure oxygen up to 12 L/min. The RSP is for medical O2 usage. The PBA consists of a non-refillable portable oxygen bottle that provides 15 minutes of oxygen and also includes a 30 foot hose to attach to the ISS oxygen lines for long term oxygen supply. The PBAs are distributed throughout the ISS, and a few are available in each module or node. Both the PBAs and the RSP can obtain their oxygen supply from high pressure tanks located on the ISS. The PBAs also attached to the ISS oxygen line for use during the pre-Extravehicular Activity (EVA) pre-breathe protocol (a method of decreasing the body’s nitrogen load and the risk of decompression sickness). The PBAs are also used for emergency oxygen usage (e.g. in a tox hazard or fire situation). An alternative to the US oxygen mask is the Russian isolating gas mask that can be used during fire or atmospheric contamination events. It provides 70 minutes of oxygen, but has been reported to be bulky, hot, and uncomfortable to wear for long periods of time. The main challenge with the current systems is that when using either the RSP or PBAs, the cabin oxygen concentration is elevated which increases the fire hazard. Modeling results have shown that when a patient is receiving oxygen, the oxygen concentration aboard the ISS rises very slowly secondary to the large volume and good mixing due to ventilation. In a much smaller spacecraft, the oxygen concentration increases much more rapidly and the risk of fire increases accordingly. Even in the ISS well-mixed scenario there is a pocket of elevated oxygen around the astronaut’s head and chest area that creates a high risk situation. If an ignition source is introduced into this area, the resulting fire can rapidly spread through the oxygen-saturated clothing and hair as well as to other astronauts who may be treating the patient. For exploration atmospheres, the ambient atmosphere may be at elevated oxygen and reduced pressure as the norm, increasing the flammability of materials in general.

Ignition hazards for medical operations during future space flights may be similar to those encountered in a typical operating room: defibrillators, laser beams, and fiber optic light sources are already available on the ISS. These tools can cause sparks when the energy impacts a metallic surface. The sparks or even the glowing embers of charring materials can provide enough initial heat to ignite some fuels, especially in oxygen enriched atmospheres. Hot electrical components in an oxygen enriched environment can be a source of ignition also. The ignition hazard may exist for a few minutes after deactivation of the source. Heat transfer is different in microgravity. Hot surfaces are hotter in the absence of gravity, and cooling times are longer.

The two technologies being pursued are: 1) the Pressure Swing Adsorption (PSA) method, and 2) the Electrochemical Proton Exchange Membrane technology. The PSA method extracts oxygen from the air by filtering out the nitrogen and then providing the oxygen to the patient. Under high pressure gas tends to be attracted to solid surfaces, or adsorbed. The higher the pressure the more gas is adsorbed; when the pressure is reduced the gas is released. In typical oxygen concentrators, air is passed under pressure through a vessel containing material which adsorbs nitrogen, allowing the enriched oxygen to pass through to the patient. The nitrogen can be released by reducing the pressure and then the system is ready for another cycle of producing enriched oxygen from air.

The Electrochemical Proton Exchange Membrane technology relies on liquid water. The Proton Exchange Membrane uses electrical energy to transport O2 from the Cathode to the Anode in the form of H2O.

Recent input from the Human Research Program Exploration Medical Capabilities (ExMC) element Advisory Board requested the inclusion of a closed loop oxygenation monitoring system that would monitor the patient’s blood saturation level via pulse oximetry, and adjust the oxygen flow accordingly through medically certified protocols. Also, the board requested an increase in the flow rate range of the oxygen concentrator module to 2-15 SLPM, which the project is evaluating. Lastly, the Integrated Medical Model was used to predict the likelihood of crew medical issues requiring oxygen, and found that the most likely event by over a factor of 10 was the treatment of smoke inhalation. Thus an inlet filter on the oxygen concentration will be needed to cleanse the ambient atmosphere prior to delivery of oxygen to the patient.

In addition to providing oxygen during medical emergencies, the Oxygen Concentrator Module could also be an option for use for pre-breathing by the crew in preparation for Extravehicular Activities (EVA). The portability of the system could allow the astronaut the ability to move freely within the spacecraft while completing the pre-breathing protocol and not be confined to the airlock. It could also be used as a first stage of an oxygen tank repressurization system. It could also be used in fire-fighting in lieu of oxygen bottles or simple respirators.

The current plan is to fly a prototype unit aboard ISS to verify the technology, and then build and fully qualify an exploration system.

NOTE: End date changed to 12/31/17 per PI information (Ed., 7/26/13)

There are many medical conditions listed on the Space Medicine Exploration Medicine Conditions List (SMEMCL) that involve either treatment with supplemental oxygen or full ventilator support. Medical conditions that the Oxygen Concentrator Module must address per decision of NASA’s Exploration Medical Capabilities Advisory Board include those which may require oxygen or ventilation use including: altitude sickness, anaphylaxis, burns, obstructed airway, upper respiratory infection, decompression sickness, headache (Space Adaptation Syndrome, other), medication misuse, radiation sickness, sepsis, smoke inhalation, and toxic exposure.

There are two US oxygen delivery systems currently used onboard the ISS; the Respiratory Support Pack (RSP) and the Portable Breathing Apparatus (PBA). The RSP uses the ISS 120 psi oxygen lines and delivers pure oxygen up to 12 L/min. The RSP is for medical O2 usage. The PBA consists of a non-refillable portable oxygen bottle that provides 15 minutes of oxygen and also includes a 30 foot hose to attach to the ISS oxygen lines for long term oxygen supply. The PBAs are distributed throughout the ISS, and a few are available in each module or node. Both the PBAs and the RSP can obtain their oxygen supply from high pressure tanks located on the ISS. The PBAs also attached to the ISS oxygen line for use during the pre-Extravehicular Activity (EVA) pre-breathe protocol (a method of decreasing the body’s nitrogen load and the risk of decompression sickness). The PBAs are also used for emergency oxygen usage (e.g. in a tox hazard or fire situation). An alternative to the US oxygen mask is the Russian isolating gas mask, which can be used during fire or atmospheric contamination events. It provides 70 minutes of oxygen, but has been reported to be bulky, hot, and uncomfortable to wear for long periods of time. The main challenge with the current systems is that when using either the RSP or PBAs, the cabin oxygen concentration is elevated which increases the fire hazard. Modeling results have shown that when a patient is receiving oxygen, the oxygen concentration aboard the ISS rises very slowly secondary to the large volume and good mixing due to ventilation. In a much smaller spacecraft, the oxygen concentration increases much more rapidly and the risk of fire increases accordingly. Even in the ISS well-mixed scenario there is a pocket of elevated oxygen around the astronaut’s head and chest area that creates a high risk situation. If an ignition source is introduced into this area, the resulting fire can rapidly spread through the oxygen-saturated clothing and hair as well as to other astronauts who maybe treating the patient.

Ignition hazards for medical operations during future space flights may be similar to those encountered in a typical operating room: defibrillators, laser beams, and fiber optic light sources are already available on the ISS. These tools can cause sparks when the energy impacts a metallic surface. The sparks or even the glowing embers of charring materials can provide enough initial heat to ignite some fuels, especially in oxygen enriched atmospheres. Hot electrical components in an oxygen enriched environment can be a source of ignition also. The ignition hazard may exist for a few minutes after deactivation of the source. Heat transfer is different in microgravity. Hot surfaces are hotter in the absence of gravity, and cooling times are longer.

The two technologies being pursued are: 1) the Pressure Swing Adsorption (PSA) method, and 2) the Electrochemical Proton Exchange Membrane technology. The PSA method extracts oxygen from the air by filtering out the nitrogen and then providing the oxygen to the patient. Under high pressure gas tends to be attracted to solid surfaces, or adsorbed. The higher the pressure the more gas is adsorbed; when the pressure is reduced the gas is released. In typical oxygen concentrators, air is passed under pressure through a vessel containing material which adsorbs nitrogen, allowing the enriched oxygen to pass through to the patient. The nitrogen can be released by reducing the pressure and then the system is ready for another cycle of producing enriched oxygen from air.

The Electrochemical Proton Exchange Membrane technology relies on liquid water. The Proton Exchange Membrane uses electrical energy to transport O2 from the Cathode to the Anode in the form of H2O.

In addition to providing oxygen during medical emergencies, the Oxygen Concentrator Module could also be an option for use for pre-breathing by the crew in preparation for Extravehicular Activities (EVA). The portability of the system could allow the astronaut the ability to move freely within the spacecraft while completing the pre-breathing protocol and not be confined to the airlock overnight.

Work on this project contains three thrusts as defined below:

CONCENTRATOR TECHNOLOGY THRUST

While oxygen concentrators are available commercially, they do not meet NASA spaceflight requirements. Accordingly, NASA has undertaken steps to correct that situation. First, in the Fall of 2009, NASA selected Lynntech, Inc. for a Phase II SBIR award to develop electrochemical membrane technology for use as an oxygen concentrator. This promising concept could dramatically reduce the size from what is currently commercially available.

In a second technology thrust, the National Space Biomedical Research Institute awarded a grant to Professor James Ritter of the University of South Carolina is developing techniques to modify commercial oxygen concentrators so that they are compatible with spaceflight. NASA’s role in this effort is to act as a collaborator: providing information on constraints associated with spaceflight hardware, particularly for oxygen systems, communicating requirements, and as a developer of ancillary technologies, such as batteries.

FIRE SAFETY THRUST

While the fire hazard associated with an oxygen concentrator is unquestionably lower than that present when oxygen from a storage bottle is released into the closed spacecraft environment, local fire hazards still exist around the patient and the concentrator equipment. NASA Glenn personnel analyzed the hazards associated with this medical treatment, and will continue to analyze the hazards associated with the hardware under development.

BATTERY TECHNOLOGY THRUST

Given the requirement for 24 hours of operation independent of vehicle power, commercially available batteries may not be able to meet the power requirements of these devices. Given their joint expertise in battery technology, a partnership of NASA GRC and industry personnel will advance the state of the art in metal-air batteries to be compatible with NASA requirements. A Phase I SBIR call was issued in 2010 for advanced battery technology to address this need, and 8 response proposals have been received and are under review.

Work on this project for the three thrusts are described below.

CONCENTRATOR TECHNOLOGY THRUST

While oxygen concentrators are available commercially, they do not meet NASA spaceflight requirements. Accordingly, NASA has undertaken steps to correct that situation. A commercial oxygen concentrator trade study was completed so that new technology oxygen concentrators can be better compared to commercial units. Based on this study, the best rated commercial concentrator was purchased to be used as a baseline unit with which to compare the new technology prototypes. Lynntech is progressing on its SBIR Phase II award, and we expect a prototype unit deliverable for testing and evaluation at the end of the Phase II contract in early 2012.

On the NSBRI work, we have toured Ritter Collaborator SeQual’s plant in San Diego, CA, and have purchased their most advanced unit for testing and evaluation since it had the highest score in the trade study.

Dr. Olson presented the status of the oxygen concentrator work at the 18th International Academy of Astronautics Humans in Space Symposium (HISS), April 11-15, 2011 in Houston, TX.

The ExMC medical oxygen use gap report was completed.

FIRE SAFETY THRUST

A laboratory is being set up to analyze the performance of new technology oxygen concentrators in exploration atmospheres. The laboratory has a vacuum chamber so that the oxygen concentrators can be tested under normoxic conditions that have been proposed for future spacecraft.

Dr. Olson described the risk and present mitigation options for “Medical Oxygen Fire Safety in Space” at the The 82nd Annual Scientific Meeting of the Aerospace Medical Association, May 8-12, 2011, at the Hilton and Capt. Cook Hotels in Anchorage, AK.

BATTERY TECHNOLOGY THRUST

Three SBIR Phase I awards have been made to develop a primary metal-air battery that will be adequate to power the flight oxygen concentrator for the required 24 hours. The awardees are Bettergy, Corp., Ionova, and Yarney. Two of these have deliverable battery cells due at the end of Phase I at the end of September, 2011.

Work on this project contains three thrusts as defined below:

CONCENTRATOR TECHNOLOGY THRUST

While oxygen concentrators are available commercially, they do not meet NASA spaceflight requirements. Accordingly, NASA has undertaken steps to correct that situation. First, in the Fall of 2009, NASA selected Lynntech, Inc. for a Phase II SBIR award to develop electrochemical membrane technology for use as an oxygen concentrator. This promising concept could dramatically reduce the size from what is currently commercially available.

In a second technology thrust, the National Space Biomedical Research Institute awarded a grant to Professor James Ritter of the University of South Carolina is developing techniques to modify commercial oxygen concentrators so that they are compatible with spaceflight. NASA’s role in this effort is to act as a collaborator: providing information on constraints associated with spaceflight hardware, particularly for oxygen systems, communicating requirements, and as a developer of ancillary technologies, such as batteries.

FIRE SAFETY THRUST

While the fire hazard associated with an oxygen concentrator is unquestionably lower than that present when oxygen from a storage bottle is released into the closed spacecraft environment, local fire hazards still exist around the patient and the concentrator equipment. NASA Glenn personnel analyzed the hazards associated with this medical treatment, and will continue to analyze the hazards associated with the hardware under development.

BATTERY TECHNOLOGY THRUST

Given the requirement for 24 hours of operation independent of vehicle power, commercially available batteries may not be able to meet the power requirements of these devices. Given their joint expertise in battery technology, a partnership of NASA GRC and industry personnel will advance the state of the art in metal-air batteries to be compatible with NASA requirements. A Phase I SBIR call was issued in 2010 for advanced battery technology to address this need, and 8 response proposals have been received and are under review.

In 2009, NASA awarded a Phase I SBIR contract to TDA, Inc. (PI: Alptekin), do further develop pressure swing absorption technology to produce oxygen enriched air. The contractor demonstrated technology that absorbed nitrogen from cabin air, producing a concentrated oxygen flow. While TDA submitted a Phase II proposal, it was not selected for award.

At the same time as TDA’s award, NASA also awarded a Phase I contract to Lynntech, Inc (PI: Cisar). Lynntech’s technology is based on electrochemical membranes, similar to what is used in fuel cells. NASA awarded a Phase II SBIR contract to develop a small, portable oxygen concentrator for spaceflight use to Lynntech in early 2010. Lynntech has proposed to continue development of their technology with the expected result after 2 years of a TRL Level 6 prototype unit that can be performance tested. If successfully awarded and developed, Phase III proposals would take the product to flight ready.

A National Space Biomedical Research Institute (NSBRI) task is also underway with the University of South Carolina (PI: Ritter) that will combine new air compressor designs with advances in Pressure Swing Adsorption (PSA) technology to develop an improved oxygen concentrator breadboard system that will supply 4 LPM of oxygen, weigh 7.2 pounds and require 106 watts of electric power.

Spacecraft Fire Safety Thrust

Future space missions will take us beyond Earth’s orbit to nearby asteroids, various moons, and Mars. The interplanetary spacecraft that will be used for these missions will have an internal atmosphere that is currently envisioned to be at reduced pressure and elevated oxygen to facilitate extra-vehicular activities. Due to the long duration of these exploration missions, medical support for the crew will include advanced life support equipment, including patient ventilation with oxygen. These increased levels of oxygen pose an increased risk of fire, especially in off-nominal procedures such as medical emergencies. Modeling results indicate that when a patient is on oxygen, the oxygen concentration aboard the International Space Station (ISS) rises very slowly due to the large volume and good mixing due to ventilation. In much smaller capsule type spacecraft, the oxygen concentration increases much more rapidly and the fire risk increases accordingly. Continuously Stirred Tank Reactor (CSTR) models of the oxygen concentration as a function of time for both the ISS and a capsule are presented as well as numerical models of the oxygen immediately around a patient in the US Lab aboard ISS under normal spacecraft ventilation and with the ventilation deactivated, as it might be in a fire emergency. Even in the ISS well-mixed scenario there is a pocket of elevated oxygen around an astronaut's head and torso that creates a higher risk situation. If an ignition source such as a friction device (drill or other tool), cautery tool, laser, or electric shock is introduced into this region, the resulting fire can rapidly spread through the oxygen-saturated clothing and hair as well as to other astronauts who are trying to treat the patient. Serious burns can occur in seconds.

Advanced Battery Development

The need for advanced battery technology is driven by the oxygen concentrator power requirements as well as the mass and volume restrictions placed on the oxygen concentrators by the governing requirements. This means the energy requirements for the oxygen concentrator may be in excess of 1000 Watt-hours/kilogram (Wh/kg) and currently there are no commercially available primary batteries that have the ability to meet that requirement.

There are only a few chemistries with a reasonable chance of achieving specific energies in excess of 1000 Wh/kg within the next few years. Metal/air systems are the most likely candidates. These systems can achieve higher specific energy because they rely on ambient air as one of the reactants and thus realize a mass benefit by not having to include the mass of the oxygen used in the reaction. The highest theoretical specific energy for metal-air battery chemistry is lithium/air at 11,500 Wh/kg giving it the best potential to realize the highest specific energy values of any battery chemistry, possibly upwards of 10 times greater than a state-of-the-art lithium thionyl chloride battery. Although lithium/air batteries are not yet available commercially, the chemistry is very similar to both zinc/air and aluminum/air making it much easier to realize the technological advances needed to develop this battery chemistry and produce a working lithium/air battery with a practical specific capacity that would meet the oxygen concentrator’s battery power and mass requirements.

NASA does not currently sponsor any development efforts related to metal air systems. There is a good match between the current battery requirements for the oxygen concentrator and the capabilities of metal/air systems. This is an area that could ideally be addressed in the context of the SBIR awards would not only enable oxygen concentrators to meet their requirements, but also advance the technology so that these lightweight systems could spin off into other areas such as power for medical devices. Accordingly, a battery SBIR call, has been released, proposals have been received and are being reviewed.

Ideally, multiple phase I SBIR awards will be issued, funded, and closely monitored in the hope that at least one will lead to a phase II SBIR effort. The effort would be structured so that at the conclusion of the phase II SBIR effort a prototype battery or smaller, multiple prototype battery modules will be delivered in addition to the final report. These deliverable batteries will undergo validation and verification testing in the Electrochemistry Branch facility at GRC. Furthermore, a phase III SBIR effort may be utilized to purchase additional prototype battery units for TRL6 validation and verification testing.

Work on this project contains three thrusts as defined below:

CONCENTRATOR TECHNOLOGY THRUST

While oxygen concentrators are available commercially, they do not meet NASA spaceflight requirements. Accordingly, NASA has undertaken steps to correct that situation. First, in the Fall of 2009, NASA selected Lynntech, Inc. for a Phase II SBIR award to develop electrochemical membrane technology for use as an oxygen concentrator. This promising concept could dramatically reduce the size from what is currently commercially available.

In a second technology thrust, the National Space Biomedical Research Institute awarded a grant to Professor James Ritter of the University of South Carolina is developing techniques to modify commercial oxygen concentrators so that they are compatible with spaceflight. NASA’s role in this effort is to act as a collaborator: providing information on constraints associated with spaceflight hardware, particularly for oxygen systems, communicating requirements, and as a developer of ancillary technologies, such as batteries.

FIRE SAFETY THRUST

While the fire hazard associated with an oxygen concentrator is unquestionably lower than that present when oxygen from a storage bottle is released into the closed spacecraft environment, local fire hazards still exist around the patient and the concentrator equipment. Glenn personnel analyzed the hazards associated with this medical treatment, and will continue to analyze the hazards associated with the hardware under development.

BATTERY TECHNOLOGY THRUST

Given the requirement for 24 hours of operation independent of vehicle power, commercially available batteries may not be able to meet the power requirements of these devices. Given their joint expertise in battery technology, a partnership of GRC and industry personnel will advance the state of the art in metal-air batteries to be compatible with NASA requirements.