Metronomic hardware design used to maintain respiratory tempo during EKG signal acquisition

I have designed, built, and tested a visual pacesetting device that enables the EKG subject to easily follow a set, clean tempo for respiration without any sudden or unexpected changes. This device is user friendly, clear, aesthetically pleasant (to preclude increased sympathetic activity), and is geared toward being used in conjunction with an independent respiratory-measuring device. Such an independent respiratory-measuring device enables the researcher to follow the subject´s breathing rate. My project is a view box with a column of 5mm diffused light emitting diodes (LEDs) that brightens while moving down at .2 Hz corresponding to a breathing rate of 12 breaths per minute. The over-arching goal of this technique was that the subject would breathe according to the pace demonstrated by the view box: the lights descending corresponding to inhalation. The implementation of this control mechanism also includes an independent respiratory-measuring device with which the researcher is able to keep track of the subject´s breathing rate. This independent device could be any one of the following: respiration pneumograph which converts changes in thoracic impedance resulting from respiration into a high level respiration signal and Respitrace^™ which uses a similar technique but has a higher level of sensitivity. The implemented circuit design includes a timer in the form of a square-wave oscillator, a decade counter to disperse the timing signal to each of the five LEDs, and a power supply. Independent of the actual circuit would be one of the above-mentioned respiratory measuring devices. This device enables the subject to maintain a more controlled and constant respiration rate, which allows for the transformation of cleaner signals in the frequency domain. Upon transformation, the researcher is now capable of studying the subject´s autonomic nervous system (sympathetic, parasympathetic). The use of this device rides on the canonical association of a lower, more controlled respiration rate producing a more robust level of parasympathetic activity. For example, a respiration rate of 12 breaths per minute is indicative (within the frequency spectrum) of more significant parasympathetic activity while hyperventilation creates a fall in the same. Fu- rthermore, breathing at a rate of 4 breaths per minute induces meditation. Greater parasympathetic activity indicates a more relaxed patient.