Welcome to the Miniguide. Before reading other sections of these instructions and before using the Miniguide, please read this important warning.WARNING: The Miniguide is designed to provide information to a blind traveller which will supplement that provided by other aids, such as the long cane or dog guide. It is stressed that it is not designed as a blind person's sole aid. Only use the Miniguide in a safe and familiar environment. Please note that drop-offs such as kerbs, edges of railway stations etc cannot be detected. Some objects may not be recognized in some circumstances (due to reflection or absorption of the ultrasonic beam). For example, smooth surfaces at an angle are often difficult to detect. Soft furnishings (or similar) can also be difficult to detect in some circumstances. If you have any doubts about your ability to use this aid, please seek assistance from an organisation with experience in mobility training.
The following instructions assume you are using a new aid that has not had its settings changed. If your aid is not new and there is the possibility the settings have been changed, then first go to the section regarding battery replacement - so that the aid can be returned to its original factory defaults.
The tactile version of the Miniguide is 65mm long, 35mm wide and 23mm thick. The two sensors, which send and receive signals from the aid, are at the front. They are small, metal cylinders with a mesh material at the front. The aid, apart from the sensors, is covered by a snug fitting bag. It is held in place by a strap which is fixed to the bag on one side and which passes between the sensors and is secured by Velcro on the other side of the aid. (Please note that the strap must not obscure the front of the sensors, ie. the strap must sit entirely within the gap between the sensors. Care must be taken when closing the bag, that the strap is positioned correctly.) A wrist strap is attached to the bag at the back of the aid.
If the aid is lying on a table, then the ON/OFF button is on the side of the aid - about 1cm behind one of the sensors. The button can be felt as a bump under the bag material, pointing out sideways from the aid. Pressing the button should result in a short vibration being felt (make sure you release the button once you feel the vibration). This indicates that the aid has been switched ON. You will probably now also feel the aid continuing to vibrate, try waving your hand in front of the aid to make the vibration speed change. Pressing the button again should result in a longer vibration being felt. This indicates that the aid has been switched OFF. Waving your hand in front of the aid now should not produce any vibration. Practise switching the aid ON and OFF to familiarise yourself with the ON/OFF vibrations.
Switch the aid ON. Now place your hand about 5cm away from the front of the aid. The aid should be producing very fast vibrations. Move your hand further away from the aid (keeping your hand in front of the aid). The speed of the vibrations should lower as the hand is moved away. Try moving your hand around, to get used to how the aid reacts. Try pointing the aid at an uncluttered wall (or ceiling) and moving the aid forwards and backwards. The vibration speed should raise and lower as the distance changes.
Now point the aid in all different directions. If you are in a small room, the vibrations will most likely always be felt. If you're in a large room, or outside, then pointing the aid in certain directions will cause the vibrations to stop. The vibrations stop when the aid can not detect an object within its current range (the current range should be 4 metres).
Please note that the aid automatically switches itself off after about one hours continuous use. So it is recommended that you switch the aid off occasionally, for example every 20 to 30 minutes. This will avoid the aid automatically switching off while it is in use.
NOTE: for the beginner, do not select any modes beyond Mode 4.
When learning how to use the aid, it is often less confusing to practice with a mode that has a shorter range eg. the 1 metre or half metre ranges. These shorter ranges mean that the aid will not be vibrating most of the time, except when there is an object close to the user.
Modes are changed by holding the button down continuously for two seconds or longer. Releasing the button after a certain number of vibrations, or pulse, selects the mode. Once a new mode is selected the aid will use that mode whenever it is switched on.
To select a mode, first make sure the aid is off. Now switch the aid ON, but DO NOT RELEASE THE BUTTON. You should feel the short ON-pulse. About two seconds after the ON-pulse you feel another pulse. While you continue to keep the button pressed, you will now feel a pulse every second.
To select a mode, you count the number of pulses after the ON-pulse. For example, to select mode 4, count 4 pulses after the ON-pulse, then release the button.
Here is a step-by-step description on how to select Mode 4 (ie. the half metre mode):
Use your hand in front of the aid to confirm that Mode 4 is really selected. You should be able to feel the vibrations stop around the half metre distance. If you misjudge the number of pulses, then just release the button and go through the above steps again.
The tactile version of the Miniguide contains two batteries, a small coin cell battery that powers the microprocessor and a small cylindrical battery that powers the vibration unit.
The coin cell battery is a CR2032 lithium battery, from this point onwards it will be just referred to as a coin cell. The coin cell holder is in the middle of the aid. After removing the bag cover, you should be able to feel the smooth coin shaped cell being held in place by some bumps. At one end of the coin cell holder there are three bumps and at the opposite end there are two smaller bumps. The coin cell can be removed by getting a fingernail under an edge and just "flicking" it up and out. Using two fingers either side of the cell makes removal even easier. If you don't want to use your fingernails, make sure whatever you do use to flick the coin cell out is non-metallic, and use only gentle force.
Before installing a coin cell, make sure that it is the right way up. The coin cell has a groove on one edge, this groove must be on the underside as you install it - otherwise the Miniguide will not work. Installing the coin cell involves sliding the cell under the three bumps of the holder, as far as it will go, and then gently pressing on the other end of the coin cell until it clicks into place.
When a coin cell is installed, you may feel the aid pulsing for about twenty seconds. This pulsing indicates that the aid has been reset and that all settings have been returned to the original factory defaults. If this pulsing is felt at any other time, it may indicate that the coin cell needs replacing or that there is a dirty connection.
If the aid starts to lose sensitivity, especially in the longer ranges, then try installing a new coin cell. Discard the old cell if the sensitivity improves noticeably with the new cell.
If you want your current settings to be saved while changing the coin cell you should do the following:
If you want to return your aid to its original factory default settings you should do the following:
The cylindrical battery that powers the vibration unit is a triple-A type battery. The triple-A battery and its holder can be felt as a ridge that runs along the length of the Miniguide. If the vibrations from the Miniguide seem to be getting weaker, then this battery may need replacing. In other words, if the sensitivity of the aid seems ok but the vibrations seem weaker, then the triple-A battery may need replacing.
If disposable batteries are to be used, alkaline type batteries will give the longest life. If rechargeable batteries are to be used then Nickel Metal Hydride types are recommended.
When installing a new battery, be sure that the battery is around the right way. On one end of the battery a small bump can be felt. This end of the battery needs to positioned towards the rear of the Miniguide, that is, away from the sensors. If the battery is placed in the wrong way, then the vibration unit will run at full speed until the battery is removed. This will happen whether the Miniguide is on or off at the time of battery installation.
A piece of ribbon is attached to the Miniguide to make battery removal easier. The ribbon is placed under the battery when it is being installed. When the battery needs to be removed, pulling gently on the end of the ribbon should lift the battery out. If the ribbon hasn't been placed under the battery when it was installed, then the battery will have to be levered out. It is much easier to lever the battery out if you work on the end furthest from the sensors. The other end is not only more difficult to remove, but the spring within the battery holder can be damaged by the levering process. To lever the battery out, place a small screwdriver blade or similar in the gap between the end of the battery and the battery holder. Then gently lever the battery out.
Here's how to install a new battery. Hold the battery by the end which has the small bump on it. Hold the Miniguide with the other hand, hold it near the front but be careful not to put any pressure or strain on the sensors - hold the Miniguide by its body. Angle the free end of the battery into the battery holder. There are a couple of plastic flaps on the holder that hold the battery in place. The battery will have to be angled under these flaps. You will know you have the battery in the right position when you can feel the battery end pushing against a spring. At this point check that the ribbon is laying across the battery holder and is under the battery. Now push the battery towards the spring while also pressing the free end down into the holder. The battery should fall into place into the holder.
Sometimes the battery is not pushed completely down into the holder. If the battery end with the bump feels higher than the other end, then push the battery towards the spring and down into the holder again until it falls into place. Remember that if the vibration unit runs at full speed once the battery is in place, and that pressing the push button has no effect, then it is possible that you have installed the battery the wrong way around. Remove the battery and try again.
If the strength of the vibration is still weak after installing a new triple-A battery, then it is possible that the vibration unit needs to be replaced. As a vibration unit starts to wear out, its vibrations become weaker and more erratic. How long a vibration unit lasts depends on how much it is used. It is anticipated that for all reasonable usage the vibration unit will last a year or longer.
The vibration unit is best replaced by a technician or a handy person. Two screws need to be loosened, this allows the vibration unit to be removed. The new vibration unit is then inserted into the socket and the screws tightened again. Be careful not to place any strain on the sensors while tightening the screws, and do not overtighten the screws. If in doubt get your nearest mobility agency to assist you.
Certain things in the environment will cause interference to the Miniguide. The Miniguide detects objects by sending out an ultrasonic pulse and then listening for the echo. If something in the area is also producing ultrasonic pulses then the aid may indicate there is an object within range when really there is no object. Air brakes on trucks and sometimes car brakes will produce ultrasonic interference. Many high pitched natural sounds contain a small proportion of ultrasounds. The interference is usually occasional and short lived. For example the interference may feel as if someone quickly waved their hand in front of the aid.
If two Miniguides are used within close proximity of each other, they will interfere with each other. Unfortunately there is no way of avoiding this problem. The aid will still be usable, but the user must be careful to determine what is interference and what are real objects.
The modes with shorter ranges are more immune to interference than the longer ranges. So if interference becomes persistent in a certain area, switching to the 1 metre or the half metre range will help reduce the problem.
The sensor closest to the ON/OFF button is the sensor that sends out the ultrasonic pulses. If you cover this sensor completely with your finger, the Miniguide should not vibrate. If the Miniguide continues to vibrate with this sensor covered, then you probably have an interference source nearby.
Avoid dropping or knocking the Miniguide. The ultrasonic sensors could be permanently damaged by a severe blow.
The ultrasonic sensors are covered by a very fine mesh. Dirt and other substances can clog this mesh. If this mesh becomes clogged then the sensitivity of the Miniguide will be reduced, or the aid will stop working completely. Store the aid in a clean location, and avoid using the aid in dusty or dirty conditions. Store the aid with the sensors pointing down to help prevent dust and dirt entering the sensors.
The Miniguide is not water proof. It should certainly not be immersed in water - or any other type of liquid. If possible, it should not be exposed to heavy rain. If you are caught in rain without an umbrella, aiming the aid downwards will help to protect the sensors from the rain. If the aid does get wet and, especially if it stops working, it is important to dry it as soon as possible. Begin by wiping away any surface water. Keep the ultrasonic sensors pointing downwards, so that any water in the sensors will hopefully drain out. If the aid does not work, place it in a warm, dry place - with the sensors pointing down. A hair drier may be used to provide warm air, but be careful not to hold it too close to the Miniguide as excessive heat could cause damage.
When using the Miniguide held in a hand, it is a good idea to put the cord attached to it over your wrist. If you want to let go of the aid to use your hand to hold something else, the Miniguide will then hang from the cord. Having the cord over your wrist is also a safeguard in the event of dropping it or having it bumped from your hand.
When storing the Miniguide, be careful to put it where heavy objects will not be dropped on it.
A list of the present modes and options, in the order in which they are selected is shown below. Following the list is a detailed discussion of each mode/option:
Mode 1 : This mode produces a vibration if there is a detectable object within 4 metres of the aid. The closer the object, the higher the speed of the vibration. This is the default mode when switching on a new aid.
Mode 2 : This mode is similar to mode 1, except that only objects within a 2 metre range will produce a vibration.
Mode 3 : This mode is similar to mode 1, except that only objects within a 1 metre range will produce a vibration.
Mode 4 : This mode is similar to mode 1, except that only objects within a half metre range will produce a vibration. This is a good mode for beginners to try, since the feedback signal is less confusing.
Modes/Options 5, 6 and 7 : These modes/options are not used.WARNING: the following modes are only recommended for advanced users of the aid. Inexperienced users should only use modes 1 through to 4.
Modes 8 and 9 : These are the watchdog modes, Mode 8 has a 2 metre range and Mode 9 has a 1 metre range. These modes are used to indicate if anyone comes within 2 or 1 metres of the aid. The watchdog modes use much less power than the other modes. The lower power consumption is a result of the aid only scanning for objects a few times a second. This slower scanning rate also means that the watchdog modes cannot detect fast changes, so the aid should always be kept stationary in these modes eg. placed on a desk. In the watchdog modes the aid will switch-off automatically after about 13 hours (for other modes the switch-off time is about 1 hour). This allows the aid to be placed on a desk for most of the day.
NOTE: this is only a low power mode if there is nothing in the 2 metre (or 1 metre) range. Once an object is detected, the unit will use normal power until the range is clear (ie. when the vibrations stop). In other words, it is only a low power mode if the aid is not vibrating. Care must also be taken to ensure there are no soft furnishings (or similar) in the 2 metre (or 1 metre) range, such objects produce faint echos which may occasionally give false alarms.
Modes 10 and 11 : These are the "gap finding" modes, Mode 10 has a 2 metre range and Mode 11 has a 1 metre range. These modes have reduced sensitivity from a distance of half a metre and onwards. Only very strong echos from surfaces such as walls will be detected at distances greater than half a metre. This reduced sensitivity helps to distinguish openings or gaps in walls eg. door openings. As a safety precaution, the sensitivity for distances less than half a metre is the same as for all the other modes ie. full sensitivity.
WARNING: the gap finding modes should be used with caution. The reduced sensitivity of these modes means that fewer objects will be detected in the range half a metre onwards. For safety, it is best to assume that these modes are equivalent to Mode 4, ie. a mode with only a half metre range. It is also recommended that the gap finding modes are only used as a "quick select" mode (see options 17 and 18 below) ie. the user should use a full sensitivity mode such as Mode 1 or 2 most of the time, and only swap occasionally to Mode 10 or 11 when required.
Modes/Options 12, 13, 14 and 15 : These modes/options are not used.
Option 16 : Selecting this option means that there will be only one setting active. When there is only one setting active, pressing the button will simply switch the aid on or off. This is the default state of the aid.
Option 17 : Selecting this option means that there will be two settings active. The user can swap quickly between two different settings. This is very useful if the user has two favourite modes eg. a 4 metre mode and a 1 metre mode. Assuming the aid is off, pressing the button will put the aid into the first setting (eg. 4 metre mode). Pressing the button again will place the aid into the second setting (eg. 1 metre mode). Pressing the button once more will switch the aid off. The aid will give one pulse when setting one is selected and two pulses when setting two is selected.
The method for changing the mode used in setting 1 is no different than the method described in the section "Changing Modes" above. That is, with the aid presently off, press and hold the switch for two seconds or more. Changing the mode used in the second setting is done in a very similar way. The only difference is that instead of starting with the aid in the off state, the aid must be in setting 1. That is, with the aid presently in setting1, press and hold the switch for two seconds or more.
Option 18 : Selecting this option means that there will be three settings active. The user can swap quickly between three different settings. Assuming the aid is off, pressing the button will put the aid into the first setting (eg. 4 metre mode). Pressing the button again will place the aid into the second setting (eg. 2 metre mode). Pressing the button again will place the aid into the third setting (eg. 1 metre mode). Pressing the button once more will switch the aid off. The aid will give one pulse when setting one is selected, two pulses when setting two is selected and three pulses when setting three is selected.
The method for changing the mode used in a setting is no different than the method described in the section "Changing Modes" above. That is, the user presses and holds down the switch for two seconds or more. The number of pulses counted after the two second gap determines the mode selected.
If the Miniguide is off and the user presses and holds the switch down (for longer than two seconds), then this will change the mode used in setting 1.
If the Miniguide is in setting 1 and the user presses and holds the switch down (for longer than two seconds), then this will change the mode used in setting 2.
If the Miniguide is in setting 2 and the user presses and holds the switch down (for longer than two seconds), then this will change the mode used in setting 3.
Modes/Options 19 and 20 : These modes/options are not used. They may be used in the future.
Option 21 : This option resets the software. That is, selecting this option is equivalent to removing the coin cell battery and pressing the button while the battery is removed (refer to the section regarding battery replacement for more information).
Modes/Options 22 : This mode/option is not used.
Option 23 : This option "locks" the current settings. This means that the current settings cannot be changed by pressing the button ie. holding the button down will no longer change modes. This option is useful in preventing accidental changes to the current settings. Organisations may find this option useful as a means of pre-programming an aid for a client. Once the lock option is selected, the only way of removing the lock option is to remove the battery and press the button while the battery is removed.