Use of Night Vision Goggles on Aero Medical Retrieval - Essay Example

Name Tutor Title: Use of Night Vision Goggles on Aero Medical Retrieval Institution Date Introduction Night vision imaging systems (NVIS) technology, specifically night vision goggle technology, has developed since 1970s. The technology is currently being put into practice in various fields. Currently, with several trained night vision goggle pilots and other members of the crew entering the civil aviation environment, operators have found themselves expressing their enhanced interest in exploiting night vision goggle operation, specifically in several specialized helicopter operations. Interest on night vision goggle operation is very pronounced in the United States and Australia. The federal aviation administration (FAA) stated in 1991 that night vision enhancement devices (NVED) need to be taken as appliance, and that incase any applicant wants an approval of operating with night vision enhancement devices, a minimum operational performance standard should be developed. Since 1994, there has been an increased interest on the use of night vision goggles in emergency medical service helicopters. The device has proved to be highly applicable in providing retrieval services, particularly at night. Night vision goggles therefore are currently being highly used in aero medical retrieval. The use of night vision devices such as night vision goggles can be justified in several ways (Hall, 2004). Justification of the use of night vision goggles on aero medical retrieval Night vision goggles are viable devices in the en-route and terminal operations during particular emergency service situations. When night vision goggles are properly used, they can enhance safety, increase situational awareness and minimize pilot workload and stress that are usually associated with operating at night. Night vision goggles are helmet-mounted devices that intensify light that is available. The goggles greatly advances night flying operations, particularly in areas with little space or surface reference lights. The use of night visions goggles enables pilots to venture out in the darkness almost as safely as when operating during the day. Advancement in night vision technology and processes of manufacturing have reduced the cost of night vision goggles. This therefore enables civilian operators including health practitioners to easily apply the night vision goggles for their operations at night (Paiva & Manaugh, 2008). Night vision devices give night operators the capability to see, plan and execute their task at night or during times of reduced visibility. Due to these reasons pilots of emergency medical service helicopters have found the use of the device to be very effective at night. The operators therefore applied two different types of night vision devices, which are thermals and image intensifiers. Image-intensifying equipments such as night vision goggles are based on light amplification. Pinkus and Dixon (2003) note that the device is applicable in areas that have some light. Image intensifying devices are capable of amplifying the available light from two thousand to five thousand times. Thermal forward-looking Infrared (FLIR) detectors operate by sensing the temperature variation between an object and the surroundings. FLIR systems are usually installed in rescue vehicles such as ambulances and helicopters. The image intensifying devices such as night vision goggles are therefore the most effective devices to be used at night (Martin, 2006). Martin (2006) argues that night vision goggles are electro-optical equipments that intensify or amplify the prevailing light instead of depending on their own light source. They are devices that permit a person wearing it to see well in poorly lit or totally dark areas. Night vision goggles give a faint, slightly murky visibility to images. Image intensifiers receive ambient light and intensify it thousands of times through electronic means. They are therefore very useful when employed in rescuing people that have got an accident in dark environment. The ambient light can come from a star, moon or sky glow. It can also come from artificial sources such as cities and towns (Davis R., & Johnson, 2008). Night vision devices are usually sensitive to a wide spectrum of light, from observable to invisible or infrared. People such as pilots of emergency medical service helicopters, using night vision goggles do not usually look through these devices. They usually look at the intensified electronic image on a phosphor screen. Image intensifiers such as night vision goggles are very useful since they provide exceptional low-light level sensitivity and increases visible imaging, thus producing the best possible identification and recognition performance. Night vision goggles also provide high declaration, low cost and power and capability to recognize individuals. The use of night vision goggles is therefore very important (Pinkus & Dixon, 2003). Due to these useful features, night vision goggles can be used when rescuing patients in remote areas that are not visible enough, that is places with minimal light. Pilots wearing night vision goggles can urgently response to major accidents, emergencies and neo-natal cases that occurs at night. When using night vision goggle, light usually enters it through an objective lens, then strikes a photo cathode that is powered by a high energy charge from the power supply. The energy charge speed up across a vacuum within the intensifier and strikes a phosphor screen, which is similar to a TV screen. The image is then focused. The eyepiece usually amplifies the image. The use of night vision goggle therefore ensures that images are well magnified for easy identification. The use of night vision goggles at night time enables winch retrievals over water. The phosphor screen in night vision goggle is purposefully colored green because the eye of human being is capable of differentiating more green shades than other phosphor colors. Similar to cameras, night vision goggles have several image magnifications. The distance at which a figure, similar to that of human being can be easily identified under normal conditions, that is under moon and starlight minus haze or fog, depends on strength of magnification of objective lens and the power of image intensifier. The maximum observing range is usually between one hundred feet and four hundred feet. The use of night vision goggles on rescue aircrafts greatly enhances the search and rescue operations at night. It also facilitates the transfer of aero medical patients within the state, particularly at night (Hurd & Jernigan, 2003). Night vision goggle is very useful since a rescue operator can perform his or her rescuing missions without demanding for any illumination sources that are active. This is very useful particularly in remote areas that have inadequate illumination sources. In case a rescue operation needs to be done at night in remote area, a rescue operator will not need adequate light for executing the task. He will only need to put on his or her night vision goggles and effectively execute the rescuing activity. The most important advantages of night vision goggles are their light weight, small size, low cost and power requirements. These features have allowed image intensifier goggles to be worn on the head and to be applied by pilots of emergency medical service helicopters and other members in the aircraft rescuing team. The features have also resulted to procurement of many night vision goggles by aero medical service providers in Australia and United States of America. Currently, research and development are being done on night vision goggles in the field of longer wavelength spectral response, higher sensitivity, enhanced resolution and larger fields of view (Tintinalli & Cameron, 2010). According to Tintinalli and Cameron (2009), observing through a night vision goggles is like observing down a tunnel. The normal field of view is usually about one hundred and ninety degrees. With night vision goggles, the field of view is usually reduced to forty degrees. The peripheral vision accustomed to, and from which a person often observe an object, is not always available. Therefore, for a pilot of emergency medical service helicopters to cater for this, he or she needs to turn his or her head constantly to scan for other objects from the sides that he or she cannot see in his or her narrow field of view. The use of night vision goggles is therefore effective under all conditions. This implies that night vision goggles can be used in rescuing operations under any conditions, that is, it can be applied when rescuing people over water, in remote places with ragged terrain and in urgent transfer of patients during the night. Though the use of night vision goggles is very significant, they have some inefficiency when using it. Night vision goggles cannot give similar level of sharpness like the one accustomed to a person during the day. The normal vision is always 20/20. Night vision goggles on the other hand can, at their best, give only 20/25 to 20/40. This is always even possible during optimal illumination alone and when a person has a high-contrast scene or target. As either the contrast or illumination reduces, night vision goggles’ visual sharpness usually drops, thus providing a person with even more fuzzy image (Johnson & Palanque, 2004). In the normal circumstances a person usually uses both eyes, binocular vision, to pick up signals that can assist him or her in estimating the distance and the depth of an object. When using night vision goggles a person normally employs the use of one eye, monocular vision, which can easily result into real problems. For instance, when a person wears a night vision goggle and observe two objects of various sizes and are side-by-side, the larger object will appear to be very near (Fleisher & Ludwig, 2010). When using a night vision goggle in observing objects that overlap each other, the objects that are in front will appear to be very near than their true position. Similarly, some objects observed through night vision goggles can appear to be very far away than their real position. This is because a person usually happens to link the loss of detail sharpness with distance. The light source, on the other hand, that is not a section of terrain feature, for instance, light on top of a tower, may appear to be very close than its real position. Night vision users usually have problems of distance overestimation and depth underestimation. It is therefore important for night vision goggle users to be informed of these possible problems, for effective use of the devices (Koppes, 2007). According to Koppes (2007), a person’s eye normally requires time to adjust from day to night vision. This is why it is always hard to see when entering a dark movie theater in the daytime. A person’s eyes require time to adjust with darkness. This also is experienced when using night vision goggles. A person basically receives a dim-day observation, thus when removing the night vision goggles, his or her eyes will require time to adjust with the darkness. The amount of time a person requires depends on how long he or she has been wearing the night vision goggles. Many individuals attain almost seventy five percent dark-adaptations in thirty seconds of removing the goggles. This is particularly significant to know when using night vision goggles as binoculars. Conclusion From the discussion, it is justified that the use of night vision goggles is very important even though it has some limitations. Night vision devices give night operators the capability to see, plan and execute their task at night or during times of reduced visibility. Night vision goggle can be applied very easily since it is light, has small size, less expensive and requires low power. Search and rescue teams are able to execute their duties very easily when using night vision goggles. Night vision goggles are viable devices in the en-route and terminal operations during particular emergency service situations. When properly applied, night vision goggles enhances safety, increases situational awareness and reduces pilot workload and stress that are usually associated with operating at night. Night vision goggles are very important since rescue operators such as pilots can execute their rescuing missions without using any illumination sources. The device can be easily applied by pilots of emergency medical service helicopters because of its advantage of being light, small in size and light in weight. Night vision goggles also have some inefficiency. It cannot give similar level of sharpness like the one accustomed to a person during the day. Bibliography Pinkus R., A., & Dixon A., S., 2003, Transmissivity and Night Vision Goggle Compatibility Data for Select Aircraft Transparencies, New York: Storming Media. Paiva T., & Manaugh G., 2008, Night Vision: The Art of Urban Exploration, New York: Chronicle Books. Johnson W. C., & Palanque P., 2004, Human error, safety and systems development: IFIP 18th World Computer Congress TC13/WG13.5 7th Working Conference on Human Error, Safety and Systems Development, 22-27 August 2004 Toulouse, France, New York: Springer. Hall L., P., 2004, The Big Island, New York: Media Creations. Martin T., 2006, Aeromedical transportation: a clinical guide, New York: Ashgate Publishing, Ltd. Davis R.,J., & Johnson R., 2008, Fundamentals of Aerospace Medicine, New York: Lippincott Williams & Wilkins, 2008 Tintinalli E.,J., & Cameron P., 2010, EMS: A Practical Global Guidebook, New York: PMPH-USA, 2010 Fleisher R G., & Ludwig S., 2010, Textbook of Pediatric Emergency Medicine. Lippincott Williams & Wilkins. Koppes L., 2007, Historical perspectives in industrial and organizational psychology, London: Routledge. Hurd W., & Jernigan G.J., 2003, Aeromedical evacuation: management of acute and stabilized patients, New York: Springer. Read More