Do you wake up every day feeling too tired, or even upset If so, then a new alarm clock could be just for you. The clock, called SleepSmart, measures your sleep cycle, and waits (67) _______ you to be in your lightest phase of sleep (68) _______ rousing you. Its makers say that should (69) _______ you wake up feeling refreshed every morning.. As you sleep you pass (70) _______ a sequence of sleep states — light sleep, deep sleep and REM (rapid eye movement) sleep — that (71) _______ approximately every 90 minutes. The point in that cycle at which you wake can (72) _______ how you feel later, and may (73) _______ have a greater impact than how much or little you have slept. Being roused during a light phase (74) _______ you are more likely to wake up energetic. SleepSmart (75) _______ the distinct pattern of brain waves (76) _______ during each phase of sleep, via a headband equipped (77) _______ electrodes (电极) and a microprocessor. This measures the electrical activity of the wearer’’s brain, in much the (78) _______ way as some machines used for medical and research (79) _______ and communicates wirelessly with a clock unit near the bed. You (80) _______ the clock with the latest time at (81) _______ you want to be wakened, and it (82) _______ duly(适时地) wakes you during the last light sleep phase before that. The (83) _______ was invented by a group of students at Brown University in Rhode Island (84) _______ a friend complained of waking up tired and performing poorly on a test. " (85) _______ " sleep-deprived people ourselves, we started thinking of (86) _______ to do about it," says Eric Shashoua, a recent college graduate and now chief executive officer of Axon Sleep Research Laboratories, a company created by the students to develop their idea.