A mechanism for maintaining a constant fly-height of a slider comprises a capacitive fly-height change sensor and an electrostatic fly-height controller. Embodiments of the present invention include emitting an electromagnetic wavelength into forehead tissue of a patient and detecting characteristics of the electromagnetic wavelength after the electromagnetic wavelength has been scattered by the tissue. A remote user device, having a display, is operatively coupled to the scrip company host system and configured to enable access to the scrip company web site. This structure makes it possible for components to be used in common and integrated, and for the coupling surfaces between the lens block and the optical fibers to be gathered together in one place, thereby enabling cost reduction and size reduction. In some embodiments, the system may vary parameters in a way substantially synchronous with physiological pulses, for example, cardiac pulses. The storage unit stores bags to enable a user to remove one of the bags through the storage unit aperture and compartment dispensing port for placement within the container cavity.