HD4i is a premier supplier of HD inspection equipment to the Industrial Marketplace. Working with a distribution network of industry leading providers of metrology and inspection equipment, HD4i can help provide your company cost effective, ergonomic inspection solutions for quality control and quality assurance applications.
dPict Imaging www.dpictimaging.com
Media Cybernetics www.mediacy.com
Old School Industries www.osi-incorp.com
View Solutions www.viewsolutionsinc.com
Midwest Optics www.midopt.com
As early as the 1830s, Sir David Brewster noted in his Treatise on Optics, "The best position for microscopical observations is when the observer is lying horizontally on his back . . . . The worst of all positions is that in which we look downwards vertically." Unfortunately, Sir Brewster's suggestions were never utilized in microscope design and sitting or standing at the instrument became the status quo. But almost 200 years later there is an ergonomic solution to an age old problem, HD Camera Solutions available from HD4i.
While conventional microscope design has not necessarily been a problem for short-term use, long-term sessions have historically created problems for scientists, inspectors, and technicians who used the instruments, making them, quite literally a pain in the neck. Microscopists were expected to suffer for the greater good of science and many have paid the price over the years with physical complaints and sometimes even permanent injuries.
The Occupational Safety and Health Administration (OSHA), in the United States Department of Labor, finds that "Microscope work is straining both to the visual system and the musculoskeletal system. Operators are forced into an unusual exacting position, with little possibility to move the head or the body. They are often forced to assume an awkward work posture such as the head bent over the eye tubes, the upper part of the body bent forward, the hand reaching high up for a focusing control, or with the wrists bent in an unnatural position."
During the 20th century microscopes became commonplace in factories manufacturing electronic components and integrated circuits for computers and the consumer electronics industry. As microscope use grew, so did concerns about usability.
Ergonomics is about finding a better fit between people and the things they do, the objects they use, and the environments in which they live, work, travel, and play.
It is the individual workers who are primarily affected, suffering discomfort, injuries, or outright disabilities, classified as work-related musculoskeletal disorders (MSDs or WMSDs). MSDs are medical conditions affecting the muscles, nerves, tendons, ligaments, joints, cartilage, and/or spinal discs. Some examples of specific MSDs are carpal tunnel syndrome, tendonitis, ganglion cysts, and lower back pain. General warning signs of MSDs are fatigue, stiffness, persistent burning or aching, reduced coordination, and a loss of grip strength in the hands.
Numerous studies have established the following ergonomic risk factors as most likely to cause or contribute to an MSD: force, repetition, awkward postures, static postures, vibration, contact stress, and cold temperatures.
In the USA, 1.8 million workers report work-related MSDs such as carpal tunnel syndrome, tendonitis, and back injuries, every year. Approximately 600,000 MSDs are serious enough to warrant taking time off from work to recover and sometimes even require surgical intervention. Evidence suggests that another 1.8 million MSDs go unreported every year.
MSDs are estimated to cost up to $50 billion a year. Employers pay between $15-$18 billion in workers' compensation costs alone.
$1 out of every $3 spent on workers' compensation goes for MSD-related claims. This does not include billions of dollars spent on medical treatment and hidden costs associated with work-related injuries. Recent increases in reported MSDs suggest that employers should be vigilant in creating work environments that are conducive to both good health and high productivity.
Percentage of Medical Problems
Reported by Microscope Operators
Anatomical Location Employee Percentage
Back (Total) 70-80
Lower Back 65-70
Lower Arms 65-70
Hands and Fingers 40-50
Legs and Feet 20-35
Sitting or standing for hours on end, bent over a microscope eyepiece is not an activity for which the body is well adapted. Microscope work requires the head and arms to be held in a forward position and inclined toward the microscope with rounded shoulders, a posture that can irritate soft tissues, such as muscles, ligaments, and disks. Poor posture and awkward positioning are the primary risk factors for MSDs that can affect full-time microscopists, who often experience pain or injury to the neck, wrists, back, shoulders, and arms. Eyestrain, leg, and foot discomfort have also been documented with long-term microscope use. In the semiconductor industry, the second leading cause of work-related medical problems is found in microscope technicians. Studies have indicated that around 80 percent of microscopists in all fields have experienced job-related musculoskeletal pain and that 20 percent have missed work because of medical problems related to microscope use. A majority of reported problems occur with the neck, back, shoulders, and arms, with a smaller percentage of microscopists reporting discomfort or injury to the wrists, hands, legs, feet, and eyes.
Factors believed to be causing these problems are head inclinations up to 45 degrees and upper back inclination at angles up to 30 degrees, awkward positioning of the arms and hands, and repetitive motions. An unaccommodating workstation that requires a microscopist to sit in awkward positions for long periods can also cause fatigue and MSDs.
The major factor with using conventional microscopes is that viewing specimens requires users to maintain a flexed neck posture while the hands are in a relatively fixed position. From the viewpoint of biomechanics, having to maintain even a slight incline of 30 degrees from the vertical can produce significant muscle contractions, muscle fatigue, and pain. In fact, it has been documented that nerves can often be pinched when the neck is overextended by this amount. Repetitive motions of the hands and the contact stress of arms resting on a hard surface can cause pain and nerve injury, leading to repetitive stress injuries and/or carpal tunnel syndrome.
This creates a dilemma for the user. If the microscope is raised high enough to prevent neck flexion, then the user is forced to bend the wrists into an unnatural position. If the microscope is lowered to bring the stage to a more neutral position, with the forearm parallel to the floor, then the neck is forced to bend. Most workers compensate for this by finding some "happy medium" between the two extreme postures, resulting in discomfort for the neck, shoulders, forearms, wrists, and hands.
Eye fatigue can also be a major problem for operators, especially if they have poor vision resulting from near and far sightedness or astigmatism. Microscopists who have moderate to severe astigmatism should wear glasses even when viewing specimens through the eyepieces. Many problems associated with eyestrain during extended periods of microscope use can be alleviated by employing video camera systems that display the component on a computer monitor or television screen. In fact, many future microscope designs may be capable of eliminating the eyepieces altogether, substituting instead a CCD or CMOS image sensor for the classical observation tubes. The digital imaging chip will be coupled to a sophisticated software analysis package that controls image capture and storage, digital processing, image analysis.
A study at Duke examined the new ergonomic designs with a group of cytotechnologists who used traditional microscopes in their work, and who had a variety of complaints associated with using that equipment. Eliminating or reducing eye fatigue is most easily accomplished by equipping the microscope with a digital video camera that displays specimen images on a television screen or computer monitor. As mentioned above, this allows operators who have eye problems, such as myopia and astigmatism, to comfortably wear their glasses during inspection of specimens.
Stereomicroscopes, the largest segment of the microscope market with a share of about 50 percent of total microscope sales. Each year over 20,000 of these ubiquitous and popular instruments are sold to educators, researchers, and industrial manufacturers. The eye tubes in older stereomicroscopes are fixed into position, usually at a 45 to 60 degree angle from the horizontal bench, and the focus knob is mounted high on the body near the pillar rack. This design has a number of significant drawbacks in terms of ergonomics and has taken a heavy toll in operator trauma over the years.
Another new technology involves a microscope design devoid of eyepieces, which substitutes a CCD or CMOS image sensor to project the image on a computer or video monitor, as discussed above. The eyepiece-less microscopes are accompanied with software packages that aid in image capture, and feature a number of applications such as multiple file storage formats, digital image processing software, and time-lapse storage. The versatility of these systems should ease the fatigue and stress associated with long term microscope use and increase operator efficiency through enhanced software features.
On one account, Sir David Brewster was absolutely correct. Peering down vertically through a microscope is "the worst of all positions" for making observations. His suggestion that microscopists should lie on their backs may not be entirely feasible, but it does capture one essential truth. The body can endure stationary positions for extended periods if it is in a neutral posture, a position that can be maintained without a concerted effort or contortions. Regular breaks, ranging from five to ten minutes per hour, are essential to reduce fatigue, especially for operators who work at microscope workstations for six to eight-hour shifts. Periodic resting of the eyes, neck, and shoulders allows operators to work for extended periods without experiencing stress-related injuries. Bending, flexing, rotation, extension, and stretching exercises during these breaks often helps to alleviate stress and will greatly benefit the operator's health in the long term. In fact, some companies have implemented a routine exercise program during short break periods. Another mechanism employed to relieve fatigue is to intermix other duties on a regular basis to reduce the length of microscopy sessions.
For some seated workstations, a footrest may be appropriate. It should provide stability and firm contact with the floor and a surface texture that keeps the feet from sliding off. It should be readily adjustable to accommodate varying user heights and have an angle of approximately 10 degrees. Toes should be above the heel, allowing the lower leg muscles to stretch.
OSHA is continuing to formulate new ergonomics standards that will require employers to assess employee exposure to ergonomic risk factors in general industry jobs. The governmental organization estimates that the new standards, if implemented, will save employers $9.1 billion annually for the next 10 years, and prevent 460,000 reported MSDs a year (perhaps even more, if unreported cases are included).
Among the concerns of OSHA officials is that basic information about common MSDs, risk factors, and the importance of reporting symptoms be impressed upon employees who must spend a significant portion of their work day on the microscope. There are a considerable number of microscopes "in the field" that are poorly equipped to provide worker comfort and reduce the incidence of injuries. If a worker's job routinely involves exposure to one or more of five known ergonomic risk factors: repetition, force, awkward postures, contact stress and vibration, then some adjustment of the work environment is necessary. However, the end result should be migration to optical systems designed to optimize both operator safety and comfort.