Electronic Low Vision Aids - Bierley’s MonoMouse

When it comes to making things appear larger, there is a limited number of ways in which it can be done.  Therefore, if magnification can be packaged in a simple to use, good quality product that appeals to a wide range of patients, there will certainly be a market, most especially if the product is affordable to the majority.

I became aware of the Bierley product range quite by accident.  My next door neighbour, whilst talking to me over the hedge one afternoon, mentioned that she had started a new role with a locally based company, who were involved in developing electronic low vision aids for the visually impaired.  Given that low vision is one of my main clinical interests, I was quite excited at the opportunity of playing with some new gadgetry, especially with such an excellent local source!
 

I must say though the range from Bierley has most certainly impressed me.  With approximately 70% of visually impaired in the United Kingdom being over 75 years of age there is a need to produce an ergonomic device which is affordable and attractive to visually impaired users, most especially the elderly.  The Department of Health has estimated that the total number of visually impaired is set to rise by 25% in the next 20 years^.  This will undoubtedly result in a greater demand for services for visually impaired people, which will include the provision of low vision aids.
 

The advancements and improvements in quality and efficiency of components have widened the use of electronic magnification.  All age groups are now regular computer users and as relative costs reduce and portability improve, it is predicted that domestic use will become commonplace.  In time the elderly will turn to electronic magnification as a principal method of magnification.  It is therefore, arguably fundamental for all low vision practitioners to discuss and preferably demonstrate the advantages of electronic devices alongside the established optical approach to prescribing magnification during the consultation.
 

Although the concept of using a CCTV as a low vision aid has been a reality for some time, the high cost of equipment and lack of portability has previously limited their use to the workplace or schoolroom.  Over recent years, the introduction of more portable video magnifiers have become available, offering good quality images at a lower cost than the conventional CCTV systems.  However, all are still in the region of several hundred pounds, which is still a limiting factor for a significant number of patients, most especially the elderly.
 

The MonoMouse is a relatively new product but its concept is probably not.  Bierley have taken an optical mouse and have modified its use as a video magnifier for the visually impaired.   I was so surprised by its sheer simplicity that I was even more surprised to find that it is one of a kind.  The use of a computer mouse, or at least something similar, may have been done before, but the Bierley team are using the advancement of CMOS technology, which results in an affordable device with low power consumption and excellent image quality.
 

Until fairly recently, video magnifiers have been using CCD (Charge-coupled device) semiconductor technology to capture digital images, in much the same way as our personal digital cameras or camcorders.  One of the drivers behind the falling prices in digital cameras has been the introduction of CMOS (Complimentary Metal-Oxide Semiconductor) image sensors.  CMOS sensors are much less expensive to manufacture than CCD sensors.  Although CMOS sensors were traditionally more susceptible to noise, had lower quality, lower resolution and lower sensitivity, CMOS sensors are now improving to the point where they reach near parity with CCD.  CMOS imagers offer more integration (more functions on the chip), lower power dissipation and smaller system size and are thus more suited to portable devices.
 

The MonoMouse is based on most recent cutting edge CMOS technology which, I assume, is one of the reasons why the image quality is so good and that the cost is low compared to other electronic aids.  The same technology allows the MonoMouse to automatically calculate the brightness of the material that is being read and make “instant” adjustments so that the screen image is always in perfect balance.  This means that a user can move the MonoMouse from a bright white sheet of paper to a piece of regular newspaper and the MonoMouse will take care of the image quality automatically. 
 

Simple to use

The MonoMouse expands the use of electronic magnification within the home environment.  The MonoMouse is simply connected via the SCART socket point in the back of a television set and the image captured is displayed on screen.  Most televisions in the UK, and throughout Europe, have been equipped with SCART connectors for the last ten to fifteen years and so the MonoMouse was designed to take advantage of a special SCART feature called auto-detect.  When the patient is watching the television on any channel, it is possible to simply press the large blue on/off button on the MonoMouse and the television screen automatically switches to display the text that the viewer wishes to read.  Once finished, the on/off button is pressed again and the television automatically reverts back to the channel that was originally being viewed.
MonoMouse is also available using the worldwide standard RCA connector for anyone that doesn’t have SCART.
 

The mouse itself fits comfortably into the patient’s hand and the simple one touch blue button is highly visible.  Patients have reported that the slightly larger than average size of the MonoMouse itself is easier to use than a standard sized optical mouse, which makes it attractive to those who find handling an issue. 
 

One of the most useful aspects of the MonoMouse is its portability.  Although it does need to be plugged into a mains socket, it still means that patients may take it on holiday, or to a relative’s when visiting.  Compared to optical devices of the same magnification, patients may retain a binocular view at a comfortable viewing distance from the TV screen, eliminating the problems of convergence and the uncomfortable reading posture that is often problematic with high-level optical magnification.  With this advantage, sustained reading tasks may be possible, although success will ultimately rest with the patient’s acuity reserve, as with all devices.
 

With optical magnification, the closer the patient is to the plus lens of the magnifier, the greater will be the field of view, and the greater the number of characters visible.  By using a television screen to view the magnified image, the field of view is not influenced by the eye-monitor distance, unless the patient is very close to the monitor, when the reverse becomes true.  Both the field of view and the magnification of the system will be largely dependent upon the screen size.  Reducing the screen size will therefore result in a smaller field of view and less magnification.
 

What amazed me about the MonoMouse is that if is so simple in its design, why had it not been done already.  Perhaps I am over simplifying the technology, but from a patient’s perspective, which is perhaps what we as low vision practitioners are more interested in, is that the MonoMouse is offering good quality magnification at a very low price.

 

 

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