User manual SCUBAPRO-UWATEC SMART MICROBUBBLE MANAGEMENT

[. . . ] The Smart COM displays a Remaining Bottom Time field, which is an estimate of the time remaining at the current depth until an ascent must be commenced. Once the ascent commences, the Smart COM has already included a prediction of the gas reserves necessary to ascend at the prescribed ascent rate and complete the necessary decompression stops. The baseline for the RBT is the "tank reserve value" which can be set via Smart TRAK in 50 PSI increments between 300 and 1750 PSI. An RBT of 0 means that if an ascent is commenced at that time and carried out at the correct ascent rate, respecting all decompression stops, the diver will be on the surface with approximately the tank reserve left in the tank. [. . . ] a reduction of blood flow to arms and legs in favor of the main organs, in an attempt to conserve body heat. The skin is the tissue that is most affected by this. Vasoconstriction does not take place right away since the diver starts with a uniformly warm body. So, nitrogen absorption in the skin at first is normal. As the diver ascends and starts offgassing, vasoconstriction is now limiting the process. So, diving in cold water makes the diver more susceptible to microbubble build up in the skin tissues and the possibility of "skin bends". The Smart computer is constantly monitoring and displaying the ambient temperature and is considering the temperature in the calculation of the decompression schedule, with the objective of minimising skin bends. For example, in normal dives, the spinal tissue is usually considered as the first tissue to affect the decompression schedule. However, when it comes to diving in cold water the Smart considers that the skin is the most important tissue. As a consequence, for a diver in cold water, the Smart may suggest a shorter no-decompression schedule, or in the case of a decompression dive, longer decompression stops. A diver can view the whole temperature profile of a dive with the Smart TRAK software and a Personal Computer. On a cold water dive a fixed model advises a 28 minute ascent, whereas the ZH-L8 ADT MB advises a 48 minute ascent. On the second dive the skin tissues, which were the leading tissues at the end of dive 1, are already relatively cold at the beginning of the dive so they have a slower speed. Hence the smaller difference in total ascent time. SMART MICROBUBBLE MANAGEMENT 6 Smart can provide a visual warning to the diver to take an advisory level stop and reduce microbubble formation. SMART REDUCES MICROBUBBLES Divers who have long term exposure to microbubbles risk soft tissue damage. Examples of soft tissue include the brain, spinal tissues and the retina. Divers who are at risk include professional divers such as instructors and dive masters who typically do a lot of repetitive diving. Sport divers who conduct multiple repetitive dives over the duration of a dive holiday are also at risk from microbubble build up. Microbubbles don't produce visible symptoms and they can only be measured with the aid of a Doppler detecting device. This hand held device generates an ultrasonic signal that strikes a microbubble in a diver's body to reflect back a distinct chirping sound. This is recorded and the recordings are then analyzed. The more "chirps" that can be heard on a recording, the greater the incidence of microbubbles in a diver. As part of a major study DAN Europe "Doppler Scanned" divers from a substantial sample of 1058 dives within 30 minutes of each dive's conclusion. The participating divers were average open water divers, who conducted typical open water dives with a large range of depths and bottom times. DAN Europe discovered that in the case of repetitive dives 67% of all divers produced High Grade Microbubbles. [. . . ] With a Smart dive computer sampling rate of 4 seconds, this program allows divers to analyze their dives with amazing detail. Smart TRAK is an invaluable tool for the diver to analyze their behavior and further improve their diving technique. The complete dive profile is displayed, as are any attention messages or alarms. The software indicates the level of nitrogen saturation of the 8 body tissues that Smart monitors. [. . . ]