Abstract: A continuous dust accumulation monitoring system, device and method monitors and measures dust accumulation via an enclosure and a machine vision subsystem which can include a digital camera. A dirty optics detection subsystem monitors optical clarity and can invoke a cleaning assembly to help maintain clarity of optics for monitoring and measuring dust accumulation.

Abstract: Speculums and spacers are used to position a retinal camera to obtain images of a fundus of an eye. In some instances, the speculums and spacers are designed to contact the eye to prevent rotation of the eye during imaging. In other instances, no contact is made with the eye. A light source may include visible light or limited to infrared light.

Abstract: A whistle is structured for promoting hygienic use of the whistle and for maximizing inlet air pressure to generate sound from the whistle. The whistle includes an air inlet having a channelizer for dividing and channeling air flow received from the air inlet through at least two different channels. A sound-generating chamber is in corresponding fluid communication with each of the channels, and an air exhaust is in fluid communication with the sound-generating chamber. The air exhaust is structured and located on the whistle body for generating a sound, and is positioned and structured at a location suitable for directing air flow away from the air exhaust in a generally downwardly and/or opposing direction with respect to a generally horizontal air flow direction at the air inlet.