Introduction to Trinocular Microscopes
Trinocular microscopes have three objectives, which are the metal tubes that contain the lenses, instead of the usual one, or even two. This type of microscope will often be used for biological or medical applications, as usually their extra functions enable more complicated and closer examination of a specimen. That third eyepiece in trinocular microscopes allows for photo microscopy. Let’s take a closer look at the objectives, as these are the business parts of a microscope. Automated microscopy, image analysis and digital photography are terms that are often used interchangeably. In a strict sense, these are very different techniques and technologies, even though each shares some elements with the others. For this discussion, we will define each of these terms, and discuss all under the general topic of automated microscopy. The current interest in automated microscopy is fueled by the rapid development of affordable, powerful personal computer systems, and the rapid advances in electronic filmless cameras. With the availability of powerful computers, display systems have increased in resolution and size, and hardware systems have been evolved specifically for computer animation, particularly games. Although games are not the reason many of us use computers, the availability of display systems on our computers which have been optimized for display of game images and graphics, as well as sound, has had a profound effect on both hardware and software that is of use for microscopists.
The continued push toward increased capability and lower costs makes computer assisted microscopic tasks both affordable and increasingly essential in the modern anatomic pathology department. An additional element encouraging the use of automated microscopy in pathology is the increasing consolidation of health care and the push to reduce costs of health care. Automated microscopy or digital photography is thought to be one mechanism to reduce costs, since it removes the cost of film and the associated personnel costs of film handling and processing. It is also believed that storing images in a digital format will in some magical way make them easily retrievable, and also permit incorporation of images directly into reports, patient records, and presentations both within the department and externally. There is also much talk of telepathology, and digital images are the key to this activity. Telepathology is viewed as making possible instant consultation by experts for difficult specimens. It is also envisioned that telepathology can permit the diagnosis of specimens prepared at remote locations by a pathologist located at another location. This implies that microscopic images can be obtained at resolutions sufficient for evaluation, and transmitted from one location to another.
Automated microscopy as a specific term implies motorization of one or more microscope functions. Specifically, an automated microscope will have a stage that is motor driven in the X and Y directions. There may also be a motorized focus system, commonly referred to as the Z axis. In some microscopes, the nosepiece is also motorized, permitting automatic selection of magnification. Additional items that may be attached to automated microscopes include slide loaders, systems to align the light source, etc. Obviously, all of this motorization of microscope functions is only useful is there is a controlling element, and this controller is generally a computer. In general terms, an automated microscope can perform some task without human intervention.
A semi-automated microscope can perform a task with some input from a human, such as putting a slide on the stage, if there is no automatic slide loader. Image analysis is the extraction of information from images, and the information extracted is generally numeric, such as area of objects within the image, density of objects, shape, etc. Image analysis can extract specific shapes from images, such as identifying objects that look like tanks in aerial or satellite images. Image analysis can identify a missing or mal-formed part on an object moving down an assembly line. Image information can be extracted based on grey level or black and white or on color planes. Image analysis is applied to an image, and the method of collecting the image is immaterial which means images can be analyzed from any source.
