Search

Biomedical instrumentation focuses on the development of methods and devices for the treatment of diseases. It is an emerging field of biomedical engineering that bridges the gap between medicine and engineering. Biomedical instrumentation was introduced during the Apollo missions when it became a necessity to measure the vital signs of astronauts. During and after the Apollo mission, biomedical engineers extended the knowledge from the Apollo mission to the research and development of more sophisticated medical equipment that are now used today. Examples include diagnostic equipment (medical imaging devices), durable medical equipment (insulin pumps and kidney machines), therapeutic equipment (infusion pumps, medical lasers, and surgical machines), life support equipment (heart-lung machines, dialysis machine, and incubator), and medical laboratory equipment (chemistry analyzer, blood gas analyzers, electrolyte analyzers, etc.). The application of these devices opens a new phase in the medical industry. Now you can have patients with terminal diseases living longer than usual. This research also extends to the field of artificial organs where vital organs, including the liver, kidneys, and heart, are designed and developed. This present opportunity allows for the effective management of diseases and disorders.

Artykuł dotyczy zagadnienia postępowania w najlepszym interesie pacjenta będącego zależnym od aparatury podtrzymującej życie, na podstawie przypadku Alfiego Evansa. Kazus ten jest szczególnie kontrowersyjny z uwagi na to, iż sąd podjął decyzję o odstąpieniu od dalszej terapii wbrew woli rodziców dziecka.

As the backbone for the treatment of patients with coronavirus disease 2019 (COVID-19), nurses have been actively playing key roles in cabin hospitals, isolation wards, and intensive care units (ICUs) for critical cases. Anesthesia nurses have their own professional specialties, such as airway management, the use and maintenance of life support equipment, including ventilators, and the use of high-flow oxygen equipment. With rich experience in emergency responses and nursing, anesthesia nurses, along with emergency nurses and critical care nurses, play important roles during the treatment of COVID-19 patients. In our hospital, 27 of 34 anesthesia nurses participated in the front-line fight against COVID-19 and did an excellent job. Anesthesia care by nurses is relatively new in China, and the role of anesthesia nurses during a disaster response has not been fully appreciated. Given their specialty, anesthesia nurses have played important roles in the treatment of COVID-19 patients. We hope that authorities will consider including anesthesia nurses in national disaster response medical rescue teams.

Coronavirus disease (COVID-19) is overwhelming hospitals with patients requiring respiratory support, including ventilators and Extracorporeal Membrane Oxygenation (ECMO). Bottlenecks in device availability may contribute to mortality, and limited device availability even in ECMO centers has led to rationing recommendations. Therefore, we explored options for ad hoc construction of venovenous ECMO using readily available components, essentially, large cannulas, membrane oxygenators, and blood pumps. As thousands of certified cardiac Impella pumps are distributed worldwide, we assembled lean ECMO by embedding Impella pumps coaxially in tubes, combined with standard gas exchangers. Ad hoc integration of Impella blood pumps with gas exchange modules, large-bore venous cannulas, regular ECMO tubing, Y-pieces, and connectors led to lean ECMO systems with stable performance over several days. Oxygenation of 2.5-5 L of blood per minute is realistic. Benefit/risk analysis appears favorable if a patient needs respiratory support but required support systems in a center are exhausted. Ad hoc assembly of venovenous ECMO is feasible using Impella blood pumps, results in stable blood flow across gas exchange modules, and thus may offer another opportunity to oxygenate, "recover the lungs" and hopefully save lives in selected patients with severe COVID-19 disease even when conventional life support equipment is exhausted. The lean design also yields inspirations for future ECMO systems.

Advances in digital health technologies have revolutionised home medical care. Yet many home medical devices (HMEDs, which includes devices referred to as ‘life support equipment’) rely upon a stable and resilient electricity supply. For users of HMEDs, interruptions to electricity supply can compromise treatment, well-being or survival. This paper addresses a challenge critical to the continued innovation in digital health technologies: the reliable supply of electricity. We bridge the current gap between electricity networks and digital health technologies through a novel method for the remote detection of the phase (that is, which part of the network that each house is connected to), in order to eliminate avoidable interruptions to supply for HMED users. We present an unsupervised phase identification algorithm capable of remote phase detection at scale, and without transformer data. This method translates data insights into actionable energy provision for HMED users and other vulnerable customers, enables more accurate management and planning, and improves electricity reliability which is critical for HMED users and the continued advances in digital health technologies.

This chapter covers zebrafish aquaculture systems preventative maintenance and troubleshooting, including the establishment of a preventative maintenance schedule and documentation of procedures performed for this purpose. Topics covered include maintenance of the macro (room) environment, maintenance of equipment and electrical controls, and provision of equipment redundancy. Examples, references, and guidance for establishing preventative maintenance and emergency procedures to provide proper upkeep of aquaculture life support equipment and prevent its disruption or catastrophic failure are discussed. Troubleshooting scenarios and case studies are included. This chapter will help provide a foundation for ensuring that the needs of the facility life support equipment are understood and properly managed. This preventative and emergency care will help to ensure the stability of the environment and safety for the animals and staff therein.

The evolution of underwater cave exploration has expanded through the use of new technologies, increased availability of reliable equipment and globally available training experiences. World record penetration dives of two decades past are conducted as routine excursions today. Exploration has moved out of vast open passages into tight, secluded sites, highly technical expeditions, remote locations and sump dives to previously unimaginable depths. Beyond stretching the limits of human endeavor, cave diving exploration has joined the ranks of serious “technical diving.” Three factors have contributed to increased range and productivity within cave diving exploration: global availability of training and mentoring, improved quality and availability of cave diving and life support equipment, and the development of advanced technologies for exploration and survey.

BACKGROUND: Currently, Army aircrews needing refractive correction are issued the HGU-4/P aviator spectacles. However, a recently published survey found dissatisfaction with the current spectacle frame. The Aircrew Flight Frame (AFF) has been used by the Air Force for over 14 yr, with the AFF-OP (Operational) style used the longest. The purpose of this study was to evaluate AFF-OP performance and compatibility among U.S. Army aircrew under operational conditions. METHODS: At 1-, 6-, and 12-wk intervals, 73 Army aircrew members wore the AFF-OP eyewear and completed a Likert scale survey. There were 14 outcome measures surveyed, with the main outcome measure being frame preference. RESULTS: The AFF-OP was preferred significantly more than the HGU-4/P spectacle. Overall, 94% of aircrew responses preferred the AFF-OP and the three highest subjective reasons for AFF-OP preference were: 1) comfort around the ears without helmet or headset; 2) comfort around the ears with helmet or headset; and 3) the effect on ear cup seal. There were no statistically significant differences in responses over the three surveyed time intervals. DISCUSSION: Army aviation aircrew preferred the AFF-OP over the current HGU-4/P spectacles. Two of the top three highest subjective reasons for AFF-OP preference coincided with two of the top three operational eyewear problems reported in the recently published survey. If Army aircrew do not wear their issued eyewear, they may purchase their own frame "out of pocket." However, this can lead to use of a frame that has not been tested for compatibility and may compromise performance of aircrew life support equipment. Walsh DV, Jurek GM, Capo-Aponte JE, Riggs DW, Ramiccio JA. Assessment of an alternative army aircrew eyewear. Aerosp Med Hum Perform. 2015; 86(12):1014-1019. Language: en

Today, personal medical devices (PMDs) play an increasingly important role in healthcare ecosystems as patient life support equipment. As a result of technological advances, PMDs now encompass many components and functionalities that open the door to a variety of cyber-attacks. In this paper we present a taxonomy of ten widely-used PMDs based on the five diseases they were designed to treat. We also provide a comprehensive survey that covers 17 possible attacks aimed at PMDs, as well as the attacks' building blocks. For each PMD type, we create an ecosystem and data and attack flow diagram, which comprehensively describes the roles and interactions of the players associated with the PMD and presents the most vulnerable vectors and components within the PMDs' ecosystems; such knowledge can increase security awareness among PMD users and their healthcare providers. We also present the basic, yet important, building blocks that constitute the steps by which each of the attacks presented is carried out. Doing so allowed us to establish the foundations for the future development of a novel risk analysis methodology for medical devices. For each attack we mapped the building blocks required to carry out the attack and found that 50% of the attacks rely upon the ability to remotely connect to the PMD, while 61% of them rely on the physical proximity of the attacker to the PMD. Finally, by surveying 21 existing security mechanisms and mapping their coverage for the attacks, we identify the gaps between PMDs' security mechanisms and the possible attacks. We show that current security mechanisms generally fail to provide protection from all of the attacks against PMDs and suggest the development of a comprehensive framework to secure PMDs and protect the patients that rely upon them.

Skin injury from medical adhesives is a known problem for neonatal intensive care unit (NICU) patients. Medical adhesive-related skin injury (MARSI) for all patient populations includes mechanical problems such as skin stripping, skin tears, and tension blisters; dermatitis reactions such as irritant contact dermatitis and allergic dermatitis; and other complications such as skin maceration and folliculitis. The most common seen in neonatal patients is epidermal or skin stripping; chronically hospitalized infants may also experience irritant contact dermatitis to a variety of adhesive products. Preventing MARSI is the goal, using the fewest and least irritating adhesive products; yet, secure fixation of medical life support equipment is imperative. This article will explore differences in neonatal skin that place NICU patients at risk for MARSI and selecting products that are most appropriate for the desired result. Barrier films and adhesive removers are also discussed in detail to determine which may be potentially beneficial to the NICU population.

A huge earthquake struck the northeast coast of the main island of Japan on March 11, 2011, triggering a tsunami with 14–15 meter-high waves hitting the area. The earthquake was followed by numerous sustained aftershocks. The earthquake affected the nuclear power plant (NPP) in Fukushima prefecture, resulting in large amounts of radioactive materials being released into the environment. The major nuclides released on land were 131I, 134Cs, and 137Cs. Therefore, almost 170 000 people had to be evacuated or stay indoors. Besides the NPP and the telecommunications system, the earthquake also affected infrastructures such as the supplies of water and electricity as well as the radiation monitoring system. The local hospital system was dysfunctional; hospitals designated as radiation-emergency facilities were not able to function because of damage from the earthquake and tsunami, and some of them were located within a 20 km radius of the NPP, the designated evacuation zone. Local fire department personnel were also asked to evacuate. Furthermore, the affected hospitals had not established their evacuation plans at that time. We have learned from this “combined disaster” that the potential for damage to lifelines as well as the monitoring systems for radiation in case of an earthquake requires our intense focus and vigilance, and that hospitals need comprehensive plans for evacuation, including patients requiring life support equipment during and after a nuclear disaster. There is an urgent need for a “combined disaster” strategy, and this should be emphasized in current disaster planning and response.

Surgery is an essential component of health systems. Anesthesia is a necessity for the delivery of safe and effective surgical care. In emerging healthcare systems, anesthesia providers are often the only providers of life support, with the anesthesia machine being the tool most often used for this purpose. The use of anesthesia machines that are not designed to match existing constraints in low-resource environment places patients in these locations at risk of suffering cardiac or brain damage from anoxia and hypercapnia, awakening during surgery, or acquiring infectious diseases. These risks can be mitigated with appropriately designed equipment.

Brain death that refers to the irreversible end of all brain activity, including involuntary activity necessary to sustain life, due to total necrosis of the cerebral neurons following loss of blood flow and oxygenation (1, 2). Using brain-death criteria, the medical community can declare a person legally dead even if life support equipment keeps the body’s metabolic processes working. However, putting an end to someone’s life creates many ethical dilemmas. Many patients perceive death as a natural part of life, or relief from pain and they may express a wish to die quickly and painlessly. They often ask the treating physician and their family to be taken home and allowed to die peacefully. However, the next of kin may want the patient to be actively treated and kept alive. The physician hopes that the patient will survive and resorts to technical means to keep the patient alive. Who should decide; the patient, the family or the physician? (Published: 6 January 2010) Citation: Libyan J Med 2009, 5: 4628 - DOI: 10.4176/091014

Visions of lunar outposts often depict a collection of fixed elements such as pressurized habitats, in and around which human inhabitants spend the large majority of their surface stay time. In such an outpost, an efficient deployment of environmental control and life support equipment can be achieved by centralizing certain functions within one or a minimum number of habitable elements and relying on the exchange of gases and liquids between elements via atmosphere ventilation and plumbed interfaces. However, a rigidly fixed outpost can constrain the degree to which the total lunar landscape can be explored. The capability to enable widespread access across the landscape makes a lunar architecture with a high degree of surface mobility attractive. Such mobility presents unique challenges to the efficient deployment of environmental control and life support functions in multiple elements that may for long periods of time be operated independently. This paper describes some of those anticipated challenges.

The Biomechanics Branch of AFRL has developed an Ejection Seat Test Database to collect, organize, and make this data useful for comparing and improving ejection seats and life support equipment. The queryable Database contains records such as photos, videos, test reports, flight equipment, and other test parameters from hundreds of ejection tests. This database is currently available to government personnel through a web interface and will help provide historical performance data to compare with future ejection seat and life support equipment testing.

The International Space Station (ISS) continues to mature and operate its life support equipment. Major events occurring between February 2006 and February 2007 are discussed in this paper, as are updates from previously ongoing hardware anomalies. This paper addresses the major ISS operation events over the last year. Impact to overall ISS operations is also discussed.

During EVA and other extreme environments, mutual human support is sometimes the last way to survive when there is a failure of the life support equipment. The possibility to transfer a coolant to remove heat or a warming fluid to increase heat from one individual to another to support the thermal balance of the individual with system failure was assessed. The following scenarios were considered: 1. one participant has a cooling system that is not working well and already has a body heat deficit equal to 100-120 kcal and a finger temperature decline to 25 C; 2. one participant has the same status of overcooling and the other mild overheating. Preliminary findings showed promise in using such sharing tactics to extend the time duration of survival in extreme situations when there is a high metabolic rate in the donor.

The International Space Station (ISS) continues to mature and operate its life support equipment. Major events occurring between February 2005 and February 2006 are discussed in this paper, as are updates from previously ongoing hardware anomalies. This paper addresses the major ISS operation events over the last year. Impact to overall ISS operations is also discussed.

We have developed a Critical Care Transport Unit (CCTU) for moving critically ill patients within the hospital. This unit carries a complete system of patient monitoring and life support equipment, all battery powered, along with other life support supplies. A back-up e merge ncy batte rylge nerator can recharge the batteries of the individual components. The unit consists of two sub-assemblies that join together by means of a unique locking mechanism. This unit has provided life support and monitoring for patients during transport and while undergoing diagnostic procedures.

Nov 2, 2014 marked the completion of the 14th year of continuous human presence in space on board the International Space Station (ISS). After 42 expedition crews, over 115 assembly & utilization flights, over 180 combined Shuttle/Station, US & Russian Extravehicular Activities (EVAs), the post-Assembly-Complete ISS continues to fly and the engineering teams continue to learn from operating its systems, particularly the life support equipment. Problems with initial launch, assembly and activation of ISS elements have given way to more long term system operating trends. New issues have emerged, some with gestation periods measured in years. Major events and challenges for each U.S. Environmental Control and Life Support (ECLS) subsystem occurring during calendar years 2010 through 2014 are summarily discussed in this paper, along with look-aheads for what might be coming in the future for each U.S. ECLS subsystem.

The AC-130U Spectre Gunship's mission of flying low and slow over hostile territory requires maximum vigilance from the aft-scanner. Diminished alertness due to the aft-scanners' reported neck/back pain was traced to the awkwardness of the aft-scanner workstation. Aft-scanners recline face-down toward the aircraft's tail while leaning downward into a bubble window to detect launches of Surface-to-Air Missiles (SAMs). To scan territory below and to the sides of the Gunship, numerous head/neck movements are required. No neck/head rests existed to support the scanner during long missions. Diminished visual alertness and long-term back and neck discomfort can result from fatigue of maintaining this "unnatural" prone position. These reports prompted the SOF DSO to request that the CSERIAC review the literature for design solutions. The comprehensive CSERIAC literature review verified adverse physiological effects and identified specific design solutions. The DSO incorporated some of these solutions and performed an evaluation of the revised design. The new design was considered by aircrew and test personnel to be a substantial improvement over the previous austere design. Improved comfort provided by padding enabled compatibility with life support equipment and more even distribution of body weight pressures throughout the anthropometric range. The new design improved body posture, positioning for mission tasks, reach, and external visibility. However, the workstation's body support for accessibility, adjustability, and comfort still need improvement. Suggestions for continuing improvements are included in this paper.

A life-cycle cost (LCC) model developed for dormant systems, the dormant system life-cycle cost model, is discussed. A dormant system is a passive type system with few, if any, moving parts. The primary cost elements are driven by shelf-life, periodic inspections/deployments, and prolonged storage. The dormant system life-cycle cost model is programmed on a Lotus electronic spreadsheet program. The model provides an input table consisting of the hardware-peculiar variables, government furnished variables, and preset report. The model primarily estimates operating and support (O&S) costs, although production costs are calculated based on unit price and number of units, whereas, the development cost is a throughput amount. The model was developed specifically for small programs such as life support equipment and chemical defense devices. >

The old saying, `Safety is paramount.' was never more true than it is in the area of ejection safety for high-speed fighter aircraft. The fighter aircraft of today has been designed to endure tremendous structural loading during dogfight or evasive maneuvers. It can fly faster, turn quicker, stay in the air longer (with in-flight refuel) and carry more bombs than its predecessor. Because of human physiological limits, the human has become the weak link in today's fighter aircraft. The fighter pilot must endure and function with peak performance in conditions that are much worse than anything the majority of us will ever encounter. When these conditions reach a point that human endurance is exceeded, devices such as anti-g suits and positive pressure breathing apparatus help the fighter pilot squeeze out that extra percentage of strength necessary to outperform the opponent. As fighter aircraft become more sophisticated, helmet trackers, helmet displays and noise cancellation devices are being added to the helmet. Yet the fighter pilot's helmet must remain lightweight and be aesthetically appealing, while still offering ballistic protection. It must function with existing life support equipment such as the Combined Advanced Technology Enhanced Design g-Ensemble (COMBAT-EDGE). It must not impede the pilot's ability to perform any action necessary to accomplish the planned mission. The helmet must protect the pilot during the harsh environment of ejection. When the pilot's only resort is to pull the handle and initiate the ejection sequence, the helmet becomes his salvation or instant death. This paper discusses the safety concerns relative to the catapult phase of ejecting from a high-speed fighter while wearing an advanced fighter helmet.

The Automated Airdrop Information Retrieval System-Human Factors Database (AAIRS-HFD) is a computerized system for the management of literature regarding human factors issues as related to airdrop systems/components. Two major categories define the focus and content of the database: (1) Human Factors Issues major topics include: Airdrop Delivery Method; Jump Mission Characteristics; Airdrop Tasks & Procedures; Hazards & Emergencies; Aerospace Biomechanical Factors; Aerospace Physiological/Medical Factors; Psychological Factors; Personnel Attributes; Load/Cargo Attributes; and Other Airdrop Human Factors Issues and (2) Airdrop Systems/Components major topics include: Static Line Personnel Parachute Assembly; Military Free Fall Personnel Parachute Assembly; Tandem Personnel Parachute System; Individual Equipment & Weapons Containers; Container Release Assemblies; Individual Protective/Life Support Equipment; Cargo/Resupply Parachute Assembly; Free Fall Cargo/Resupply Parachute Assemblies; Cargo/Resupply Container Systems; Cargo/Resupply Platform Systems; Tools & Equipment for Rigging; Tools & Equipment for Derigging; Aircraft Components; Training Devices; and Other Airdrop Systems/Components. System capabilities include: text and keyword searches; on-screen viewing; printed reports; maintenance of source and keyword databases; and automated backups. This report contains detailed information regarding the operation of AAIRS-HFD's search modules including instructions for installing the system, conducting keyword and text searches, viewing results on-screen and generating printed output.

Medical equipment has become more intelligent as the manufacturers have incorporated the latest microprocessor based technology. Equipment malfunction can be caused at any time by inherent errors in the control program but it is particularly important that this is designed to cope with the effects of electrical interference which, in addition, may cause corruption of the software. We have considered interference found in the mains supply in the hospital environment. Using a test protocol with appropriate interference simulators, a wide range of medical equipment was removed temporarily from use and its immunity to electrical mains borne interference tested. Battery operated mains rechargeable devices were unaffected by mains voltage variations including drop-outs and sags whereas mains powered devices were affected to varying degrees of severity. In particular, repetitive drop-outs caused loss of power due to fuse blowing in some life support equipment. Impulses affected 25% and pulse bursts 50% of the equipment tested with some evidence that the more recent designs coped better. The EEC Directive on electro-medical compatibility compliance may cause the design of equipment to be improved but hospitals will have to cope with the above problems in their existing equipment for many years to come.

Determining the location and distribution of cockpit and aircrew-related equipment within the wider debris field of a military aircraft crash site is an essential first step in planning and executing the recovery of missing aircrew members presumed still to be on the site. Understanding the spatial relationship of these materials improves the likelihood of finding and recovering the remains of the aircrew during the excavation of an aircraft crash site. Since the greater portion of these unaccounted for crewmembers were involved in aircraft with single-seat cockpits or cockpits with two or three seats in tandem, pre-analysis of the debris pattern may be more-or-less straightforward. Larger, multiple-personnel aircraft, on the other hand, create a potentially more complex analytical situation given the aircrew's greater freedom of movement within the aircraft. Nevertheless, the same fundamental principles apply and, indeed, have been successfully so for some time in the civilian arena. But older aircraft crash sites, i.e., those dating to World War II, Korea, or the Vietnam conflict, have been and still are undergoing taphonomic processes that progressively alter these relationships. The following will illustrate that exchange of information between the anthropologist/archaeologist and the life-support analyst is required to maximize the effectiveness of field recovery and demonstrates the relationship between the recovery of life-support equipment and human remains and the effect that aircraft type has on this relationship.

About 450 German hospitals and over 2700 doctors are now being investigated for accepting bribes from manufacturers of heart valves, life support equipment, cardiac pacemakers, and hip joints. These latest figures were released by Horst Rosenbaum, state attorney in the region of Wuppertal and North Rhine-Westphalia, in the continuing saga of the so called …

Maintaining a high quality atmosphere is one of the essential factors in effective operation and performance of a nuclear submarine. Deviations from the Bureau of Medicine & Surgery (BUMED) atmospheric contaminant limits can result in a submarine altering operations, surfacing to ventilate or even aborting missions. Continuous shipboard monitoring of the major constitutents and contaminants of the air provides the atmosphere quality data needed to insure safe operations and assist the Medical Community in evaluating potential problems. This task is currently accomplished with the Naval Reaearch Laboratory's (NRL's) Central Atmosphere Monitoring System (CAMS) MK I. CAMS MK I is a combination mass spectrometer-infrared atmosphere monitor that for the first time provides the Fleet with a reliable, service approved analyzer with the ability to monitor the atmosphere in various submarine locations. Concentrations of oxygen, nitrogen, carbon monoxide (CO), carbon dioxide (CO2), hydrogen, water vapor, and three refrigerants (R-11, R-12, R-114) are monitored continuously and displayed in a digital format for the crew. The atmosphere throughout the submarine can be analyzed rapidly (within a few minutes) by obtaining air samples from various submarine locations through a compartment selector valve. A second generation of the CAMS, CAMS MK II, is currently under development. CAMS MK II will significantly expand the flexibility of CAMS MK I while maintaining its high level of reliability. The expanded capability of CAMS MK II is designed to meet the future requirements of the Submarine Fleet. Using Navy approved microprocessors, CAMS MK II will automatically acquire, store, and interpret atmosphere data. Software changes to the CAMS MK ***IT'S powerful and flexible data processor will allow ready expansion of monitoring capability to meet the changing requirements of the Fleet as well as allowing CAMS MK II to control other life support equipment. A description of CAMS MK I is presented as well as examples of operational accomplishments. A technical description of the CAMS MK II development program also is presented along with the system approach for integrating the life support equipment.

The successful demonstration of the maturity of the regenerative Environmental Control and Life Support System (ECLSS) is an essential factor in the development of the Space Station. The present paper provides an overview of the Space Station ECLSS Test Bed Program, the mechanism by which the maturity of regenerative ECLSS technologies is demonstrated. Attention is given to the background regarding the ECLSS development, the purpose of the Space Station ECLSS Test Bed Program, the objectives of this program, the three facility elements of the ECLS Test Bed, the technical approach, the design support test phase, the testing of the Regenerative Life Support Equipment (RLSE) systems, advanced prototype testing, fallback testing, and the integrated test phase. The integrated test phase will provide the final demonstration of the regenerative ECLSS technology maturity.

Divers operating out of bases in deep water face conditions that are in many ways different from those familiar to surface-based divers. Although many of the hazards encountered are well known, others are new or greatly increased. The correct design and operation of the diver's personal life-support equipment are vital for safe and efficient operations. Personal equipment serves primarily to control the environment in the immediate vicinity of the diver's body. Certain factors, such as the partial pressures of gases, temperature, and gas contaminants, must be kept within limits, or dangerous consequences result. Others, such as general comfort and the ability to communicate, will affect the efficiency of the diver and thus have a direct bearing on safety. A number of different approaches have recently been taken in the development of personal life-support equipment. They include various combinations of breathing systems, head gear, and exposure suits. The ultimate intentions of all are to allow the diver to work efficiently and safely. Several systems are analyzed and compared with special attention to the solution of environmental and other hazards. Although many of the concepts are still experimental, there are some which give significant promise.

The purpose of a helmet's retention assembly is to keep the helmet firmly and securely in place on the wearer's head, thus preventing the exposure of the cranium to direct impact. The standard SPH-4 retention assembly is prone to excessive elongation under stress, and allows excessive helmet displacement and cranium exposure. A modified SPH-4 retention assembly, reinforced with 0.75-inch tubular nylon webbing; was manufactured in this laboratory and tested quasi-statically on a testing machine which exerted a force at a constant speed. A standard SPH-4 retention assembly was also tested as a control. The reinforced retention assembly withstood a 450-lb load without failure. Elongation of the reinforced retention assembly, measured at 300-lb load, was almost 50 percent less than that of the standard retention assembly measured at the same load. Keywords: Retention system; Life support equipment; Chinstrap; Protective clothing.

A ring-shaped inflatable head/neck restraint system for ejection seats is being developed at the Crew Systems Department, NADC. The purpose of this system is to reduce neck injuries due to violent forward head rotation at the time of ejection thrust and parachute opening shock. Inflation of the neck ring will be conducted by a solid propellant gas generator. Design considerations include form-and-fit, cost effectiveness, packaging and integration into life support equipment.

Injury data were obtained from the U.S. Army Safety Center for the occupants of U.S. Army aircraft who were both wearing aviator helmets and involved in duty-related aircraft accidents, for the period beginning on 1 January 1972 and ending 1 January 1983. The injury data were correlated with the physical condition of the involved helmets, examined by the authors under an Aviation Life Support Equipment Retrieval Program. Each helmet's performance was evaluated with regard to current injury prevention capabilities and potential improvements for future helmet design. For consistency, only the 208 SPH-4s in the data base were fully analyzed. Combat damaged helmets were excluded from this analysis.

The Clothing and Life Support items listed in this report are the only items presently available that are applicable for use in a desert environment. The current Common Table of Allowance (CTA) 50-900, Clothing and Individual Equipment does not currently authorized the use of all these items in the desert environment. During the period 1963-1968, many new items of clothing and equipment entered the Army system to meet the needs of the soldiers in Southeast Asia. As a result of the urgency of the situation, many of these items were fielded without the benefit of extensive testing, and although there were shortcomings in some of the items, others became highly popular and are still in wide use today. Another aspect of this is that many of the items introduced for use in Southeast Asia may not be suitable for environments other than hot-wet. Today our attentions are focused on other parts of the world, some of which are characterized by the hot-wet environments similar to Southeast Asia, while still others are typical of hot-dry environments found in the desert areas of the Middle East. Our own experience in these areas, coupled with lessons learned from other nations which have had for conduct military operations under such conditions, has shown that there is considerable room for improvement in clothing and equipment items for these environments. Two other factors provided stimulus for the preparation of this report. One was the rapid technological changes occurring in industry. These changes are reducing our ability to depend on previous manufacturing technologies as pointed out in an earlier study performed at this Command. The second is the introduction of many new materials and fabrics in recent years which could be utilized to greater advantage by the Army.

A Shuttle EVA/IVA Requirements Study was conducted by Hamilton Standard for NASA. The objectives of this study were to establish a baseline EVA approach for Shuttle and to prepare requirements for the EVA equipment required to support these operations. This paper presents the results of the EVA life support requirements definition effort and defines candidate configurations which meet these requirements. Various subsystem and system concepts were identified and evaluated to determine the most desirable approaches. Both independent and umbilical configurations are considered. Because certain EVA missions could involve contamination-sensitive payloads, the impact of integrating noncontaminating equipment is also considered.