A low computational power digital audio player achieves beat continuous transitioning between digital audio pieces based on beat metadata, which can be generated via offline processing on a higher computational power computer or via background or idle processing on the digital audio player. The method for acquiring and analyzing cardiac data of a patient includes processing the cardiac images for detection and diagnosis of heart diseases. The optical device additionally includes a third waveguide concatenated to the second waveguide. A pretension of a spring device between the shorter and the longer bar arm has the effect that the bar arms are urged to carry out a swiveling motion relative to each other, thereby applying a ventrally or dorsally directed translatory force onto a lower leg fixation device in an area close to the knee. The compositions of the invention are also effective in preventing or alleviating emesis associated with migraines or other medical conditions such as chemotherapy or radiotherapy, as well as other symptoms of migraines including phonophobia and photophobia.