WO2000079373A1

WO2000079373A1 - Computer peripheral user interface system and method for guiding the use thereof

Info

Publication number: WO2000079373A1
Application number: PCT/NL1999/000381
Authority: WO
Inventors: Jan Willem Elkhuizen; Willem Hendrik Bakker
Original assignee: Jan Willem Elkhuizen; Willem Hendrik Bakker
Priority date: 1999-06-21
Filing date: 1999-06-21
Publication date: 2000-12-28
Also published as: AU4533699A

Abstract

A computer peripheral user interface system for inputting instructions to a computer provides for different actions for inputting the same instruction. The use of the alternative actions or types of action to which one or the other of the actions are associated is detected. Intensities of use of the types of action are monitored. Too intensive use of one of the types of action is signaled. In response, the user is influenced to decrease the intensity of use of that type of action in favor of another one of the types of action. Thus, the risk of RSI can be reduced substantially without substantial loss of productivity or needing complicated measurement facilities. A method and a program for guidance and an integrated solution for improved support are described as well.

Description

COMPUTERPERIPHERAL USERINTERFACE SYSTEMAND METHOD FORN

GUIDING THE USE THEREOF

TECHNICAL FIELD

The invention relates to a computer peripheral user interface system for manually inputting instructions into a computer and to a method and a computer readable data structure including a computer program for guiding the use thereof. Such interface systems, methods and data structures are for instance used for inputting data and for interactive control of a computer system.

BACKGROUND ART

A problem associated to the intensive use of computer peripheral user interfaces systems such as a keyboard, a mouse, a touch pad, a track ball and a joy stick is that, in the course of time, many users start to suffer from a Repetitive Strain Injury (RSI), such as a Carpal Tunnel Syndrome (CTS) caused by nerves, tendons and/or blood vessels being pinched in the carpal tunnel. Other injuries of this type include inflammations of tendons, tendon sheaths and muscles.

RSI is generally held to be caused by prolonged specific strain in combination with too little relaxation and variation of movement. Particular risk factors are prolonged tension in the muscles, for instance due to lack of support or inadequate support of limbs and prolonged maintenance of the same angulation of joints to which collagen connective tissue as well in ligaments and capsules as in muscles is particularly sensitive. One approach for the prevention of such injuries is to monitor the use of a keyboard in order to warn the user that a break is to be taken. In U.S. patent specification 5,305,238 it for example described to measure the amount of data entered into a computer and to establish intermittent rest periods based on the measured data amount. In international patent application WO 96/36033 it is described to determine the force exerted on the keys and to signal critical finger impact values.

Although intermittent rest periods appear helpful for avoiding injuries as discussed, such rest periods are often not observed and go at the expense of short term productivity. Measuring impact values requires relatively complicated measurement means.

Another approach to counteract the development of such injuries is to provide computer peripheral user interfaces of an alternative design, such as separate left and right keypads as described in U.S. patent specifications 5,122,786 and 5,137,384. However, an efficient use of such unusual user interfaces requires training and a relatively long period to become accustomed therewith.

SUMMARY OF THE INVENTION

It is an object of the present invention to contribute to the prevention of Repetitive Strain Injuries without entailing the disadvantages of substantial losses of short term productivity, requiring particular user discipline, requiring impact measurement facilities or requiring intensive training or long periods of habituation.

According to the present invention, this object is achieved by providing a computer peripheral user interface system according to claim 1.

According to the invention, this object can also be achieved by guiding the use of a computer peripheral user interface system in accordance with claim 26. The invention can also be embodied in a computer readable data structure including a computer program according to claim 30.

By monitoring the intensity with which different actions or types of action are performed and by at least suggesting a change to other actions or types of action (where available for inputting functionally identical instructions) in response to identified excessive use of one action or type of action, the risk of RSI can be reduced substantially without substantial loss of productivity. Furthermore, complicated measurement facilities are not required and habituation is quick.

Alternative operating actions which may be suggested can for instance be the suggestion to use the keyboard instead of the cursor and pointer control device (such as a mouse) for inputting instructions, where this alternative is available, if the cursor or pointer control device is used too intensively.

A particularly advantageous mode of carrying out the present invention is to distribute the execution of operating actions for inputting the same instructions over the left hand and the right hand. By carrying out a type of operating actions which is conventionally carried out with one hand only, such as the actions of operation of a mouse, with both hands and by monitoring and influencing the distribution of such operating actions over the hands of the user, the intensity of occurrence of such operating actions carried out with the same hand for inputting a given amount of instructions is substantially reduced and thereby the risk of Repetitive Strain Injury is substantially reduced. Further objects, features, effects, advantages and details of the present invention are set forth below with reference to a presently most preferred embodiment shown in the drawings . BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a perspective view of a computer peripheral user interface system according to an example of the present invention;

Fig. 2 is a schematic view in cross-section along the line II-II in Fig. 3 of the device shown in Fig. 1 ;

Fig. 3 is a schematic view in cross-section along the line III-III in Fig. 2 of the device shown in Fig. 1;

Fig. 4 is a schematic representation of a structure of functional components of the device shown in Fig. 1; and Fig. 5 is a flow chart of steps of an example of a method according to the invention.

MODES FOR CARRYING OUT THE INVENTION

The computer peripheral user interface shown in Figs. 1-3 is formed by a keyboard 1 with operating members 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 50 for right-handed operation and with corresponding operating members 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 51 for left-handed operation for controlling the same functions as the corresponding operating members for right-handed operation. Of these corresponding right-hand and left-hand control members, the members 2, 3 are trackballs for controlled movement of a pointer or, depending on the application, a cursor over a graphic display screen. The members 4, 5 are "right mouse buttons" and the members 6, 7 are "left mouse buttons", all in the form of toggle switches. The buttons 50, 51 are press buttons to which for instance the "double-click" function can be assigned. The members 8-17 are respectively right-hand and left-hand space-bar, alt, start-menu, control and shift buttons. Reference numerals 18, 19 designate corresponding sets of keys forming numerical key pads to be operated right-handed or left-handed if an alternative function for these keys is activated. Reference numerals 20, 21 designate corresponding scroll wheels which are, as such, well known in the art. The functional structure of the key board 1 is illustrated by Fig. 4 which, for the sake of clarity does not show all possible connections for monitoring and left- hand and right-hand operation but only those associated to operation of the pointer or cursor operating members and associated buttons and scroll wheels, these operating members are referred to as mouse operating members.

The right-hand and left-hand mouse operating members 2, 4, 6, 20, 50 and 3, 5, 7, 21, 51 of the keyboard 1 are connected via lines 22, 23 to a registration portion 25 of a keyboard control system 26. The alphanumeric field of keys 27 is connected to the registration portion 25 of the keyboard control system 26 via a line 24. This configuration of operating members, connections and registration facilities form a structure for detecting intensities of left-handed and right-handed operating activity of the keyboard 1, assuming that the right-hand mouse operating members are exclusively operated right-handed and the left- hand mouse operating members are exclusively operated left- handed. Depending on preferences, the operating activity of keys of the field 27 can either be disregarded, registered only as far as the use of some of the keys 18, 19 in the numerical key mode is concerned or be registered completely, assumptions regarding the hand operating different keys being based for instance on the ten fingered typing system. The keyboard control system 26 further includes a processing portion 28 in which signals originating from the keys and other operating members are processed into command instructions which are communicated to a computer via a _ g_

connection 29. The processing portion 28 also fulfills the function of comparing detected intensities of left-handed operating actions with detected intensities of right-handed operating actions. In response to the result of the comparison between detected intensities of left-handed operating actions with detected intensities of right-handed operating actions and the comparison of that result with reference data, the processing portion 28 signals either a balanced situation or an unbalance between the intensity of left-handed operating actions and the intensity of right-handed operating actions .

In response an intensity of use above a predetermined threshold level in combination with a signaled unbalance, the processing portion 28 activates the keyboard 1 to influence the user to change the balance between the intensity of right-handed operating actions and left-handed operating actions during the further use of the keyboard 1.

For this purpose, the keyboard 1 is provided with a switching structure 30 operatively connected to the processing portion 28 via a connection 31. The switching structure 30 is responsive to the processing portion 28 for switching power on lines 32, 33 on or off. If the power on line 32 or 33 is switched on, a red lamp 34 or, respectively 35 is switched on, indicating to the user that further use of the right-handed or left-handed mouse operating members and, if applicable in view of the setting of the keyboard, numerical key fields entails an increased risk of RSI. Power supply for the lamps 34, 35 is provided in the form of a power supply line 36 of the connection 29. It is observed that signals advising to decrease the intensity of use of left-hand or right-hand operating members can also be displayed on the computer display, if suitable keyboard software runs on the computer. The processing portion 28 can also be set to influence a user to decrease the relative intensity of left-handed or right-handed operating actions by temporarily changing its setting such that commands entered via left-hand or right- hand operating members result in the issue of warning sounds or are even completely disregarded. In a default setting, the processing portion 28 is programmed by a data structure stored therein to operate in a visual warning mode for switching the lamp 34 or 35 on if a first level of unbalance between amounts of left-handed operating actions and amounts of right-handed operating actions is exceeded, an auditive warning mode if the level of unbalance has exceeded a second higher threshold value and an operating member blocking mode if the level of unbalance has exceeded a third, highest threshold value.

The data structure in the processing portion 28 includes a cyclic computer program of which the functional structure is shown in Fig. 5. A first portion 37 of this program consists of determining the intensity of left-hand and right-hand operating actions. For this purpose left-hand and right-hand receipt storage memory positions of the processing portion 28 are repeatedly sampled to check whether signals indicating operating actions have arrived (steps 38) . After each sampling, a determination is made whether signals indicating a predetermined amount of operating actions have been received, if not the sampling is repeated if yes the program continues with a new comparison of the amounts of left-hand and right-hand operating actions (steps 39) . As a first step, the memory (IS) of arrived signals is read and erased (steps 40) . Then the value of operating actions as read is added to the count "L" or to count "R" to update the values of amounts of left-hand and right-hand operating instructions (steps 41) . The steps 41 also include the subtraction of values of amounts of operating actions older than a predetermined age, so that a value for operating actions over a substantially constant, running time window is obtained.

Next, it is determined whether the absolute value of the difference between the count "L" and the count "R" exceeds a threshold value T (step 42) . If no, power on lines 32, 33 is switched off or kept switched off (step 43) and the program returns to steps 38. If yes, it is determined- which of the count "L" and the count "R" is largest (step 44) . If count "L" is largest, power on line 33 is switched on to activate lamp 35 indicating that left-hand operation should preferably be avoided (step 45) . If count "R" is largest, power on line 32 is switched on to activate lamp 34 indicating that right-hand operation should preferably be avoided (step 46) .

Next, it is determined whether the absolute value of the difference between the count "L" and the count "R" exceeds a threshold value U larger than threshold value T (step 47) . If no, any functionally disconnected operating members are reconnected to become operative again (step 48) and the program returns to steps 38. If yes, depending on the side at which the lamp 34 or 35 has been switched on, the operating members 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 50 for right-handed operation or the operating members 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 51 for left-handed operation are functionally (not physically) disconnected, so that operating these operating members remains without any effect (step 49) and the program returns to steps 38.

It is observed that for the sake of conciseness the program steps for activating or deactivating the auditive warning mode are not included in Fig. 5. It will be clear that these are of essentially the same structure as the steps 47-49 for activating or deactivating the blocking mode . Since for detecting left-hand operating actions and right-hand operating actions distinct left-hand operable and right-hand operable operating members are provided, it can be determined in a very simple manner whether operating actions are carried out left-handed or right-handed.

However, it is also possible to provide a single operating member which is left-hand operable and right-hand operable and which is provided with detectors which indicate whether it is being operated left-handed or right-handed. This is for instance advantageous if the operating member is a joy stick for controlling computer games . Such sensors can for instance be provided in the form of light (or touch) sensors 68, 69 for sensing whether the operating member 53 is operated from the right (i.e. right-handed) or from the left (i.e. left-handed) . Provision of a single operating member for cursor and pointer control instead of two of such operating members allows the keyboard to be of a more compact design. This is of particular advantage if the keyboard is part of a portable system. Instead of or in addition to counting amounts of operating actions, the intensity with which particular operating actions or types of operating actions (such as left-handed and right-handed operating actions) are carried out can also be determined by monitoring the number of time intervals of for instance four, eight or up to sixty seconds during which at least one operating action of the type at issue is performed. For instance for a person who can only type slowly, the load caused by typing concentrated for an hour is not very different from the load caused by typing for the same period of time by a person capable of typing very fast, although the latter person will have carried out a far larger number of operating actions.

The intensity of the use of delete and backspace keys is also monitored. In response to the intensity of use of _ _{χ Q} _

these keys increasing beyond a predetermined level and also in response to the intensity of use of these keys increasing by more than a predetermined factor compared to an average for a user, a suggestion to take a break or to switch to other activities is generated. This feature can also be applied advantageously without the detecting, comparing signaling and influencing steps as discussed above.

A particularly effective contribution to the prevention of RSI is obtained if the operating members of which the intensity of use is monitored and influenced include at least the two-dimensionally operative operating surfaces and operating members for controlling displacements of a pointer or cursor on a graphic display, such as the track balls 2, 3, because operation of such operating members entails particularly high and prolonged stress in the area of the wrists, the shoulders and the neck.

Since the distinct left-hand operable and right-hand operable operating members 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 50 and 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 51 are adapted for controlling mutually identical functions, the control of these functions can be carried out completely by left-handed operation as well as by right-handed operation.

However, instead of or in addition to left-handed versus right-handed operation, alternative operating actions which may be suggested can for instance be the suggestion to use the keyboard instead of the cursor and pointer control device (such as a mouse) for inputting instructions, where this alternative is available, if the cursor or pointer control device is used too intensively. The suggestion can for instance be provided in the form of a general suggestion too use the keyboard instead of the cursor and pointer control device where possible. It is also possible to suggest particular shortcut key combinations for instructions which the user has just inputted using the cursor and pointer control device.

Moreover, it can also be suggested to take a break if the aggregated intensity of use of different operating actions over a given period of time exceeds predetermined threshold values .

The keyboard 1 is further provided with support portions 70, 71 located inside and rearward of respective- toggle switches 4-7, for supporting the thumbs 61 of a user operating the trackball 2 or 3. Such support area's for the thumb are of particular importance for avoiding RSI which often occurs in the form of tendinitis to the extensor or the abductor muscles of the thumb.

At the outside of the toggle switches 4-7 support portions 72, 73 are located directly adjacent these toggle switches 4-7 for supporting the little finger side of the hand 62 of a user operating the trackball 2 or 3. Support of the outside of the hand further reduces prolongedly maintained muscle stress in the hand and thereby further reduces the risk of RSI.

Since the two-dimensionally operative operating surfaces 2, 3 are located in areas on opposite lateral sides of a field of alphanumeric keys 52 of the keyboard 1, these operating surfaces 2, 3 can be reached quickly and effortlessly by a pivoting movement of the fore-arm, which further contributes to a relaxed operation of the keyboard 1, even without left-hand/right-hand detecting, monitoring and influencing.

The keys of the numeric keypads 18, 19 are each formed by a number of the alphanumeric keys which can be activated as an alternative operating mode in addition to the alphanumeric function. To support the prevention of typing errors, the functional condition or operating mode of the keys 18, 19 is displayed on the keys in accordance with the active function of the respective keys. For this purpose, the keyboard is equipped with a selectively activatable backlighting which increases the visibility of respective characters on the keys . This function is also available for indicating whether a caps lock mode is active or not, by either increasing the visibility of uppercase or lowercase characters of the keys in accordance with the caps lock function being active or not, while the numeric lock mode is inactive. Although the function of making different characters on the keys visible or better visible in accordance with the operating mode of the keyboard is particularly advantageous in combination with the added operating mode of the double numeric key pads 18, 19 for monitored left-hand and right-hand operation, it can also be advantageously applied to otherwise conventional keyboards .

The keyboard 1 is further equipped with a tilting cursor control button 53 in a central area of the field of keys 52. In this position, the cursor control 53 can easily be reached with minor movements of a hand and a fore-arm of the user. Moreover, in particular in combination with double operating members the central location of the cursor control is advantageous, because it increases flexibility regarding the choice of other hand with which this control is to be operated. This location of the cursor control 53 facilities is of particular advantage in combination with the V-shaped configuration of the rows of keys of the field of keys 52, since due to this configuration, space for the cursor control is available in a central proximal area of the keyboard 1, also if the keyboard is not equipped with monitored and influenced left-hand and right-hand operation facilities .

In the keyboard 1 according to the present example, the monitoring means and the influencing means are included in the keyboard structure. It is also possible to make use of a computer application program - for instance provided as a directly or indirectly operable data structure stored on and readable from a data-carrier such as a floppy disc or a CD-ROM or made available in the form of a downloadable file on a network or in the form of interactive signals transmitted via a network - running on the computer to be operated.

However, if the keyboard is self-supporting regarding its monitoring and control functions, the need of providing and installing separate software and the need of providing and maintaining different programs for operation under different operating systems such as Windows, MacOS and Linux can be avoided. To further reduce the risk of RSI, the keyboard 1 further includes a fore-arm support 54 adjacent the field of alphanumeric keys 52 for supporting fore-arms of a user. Such a fore-arm support 54 is of particular advantage in combination with double operating members for controlling displacements of a pointer or a cursor on a graphic display which are integrated in the keyboard. This generally reduces the need of lifting and displacing the fore-arms to reach different operating members, so that the time the fore-arms can be left resting on the fore-arm support 54 is increased. However, such a fore-arm support 54 and below described features thereof can also be employed advantageously in a keyboard which is not equipped with any or all double operating members as described and/or facilities for detecting, monitoring and influencing the balance between intensities of use of different operating actions or types of operating actions.

As is best seen in Fig. 3, the fore-arm support 54 is mounted such that projected continuations 55 of the fore-arm support 54 extend over the field of alphanumeric keys 52 spaced above the field of alphanumeric keys 52. This allows to type on the keys in the field 52 with the fore-arms 56 resting on the fore-arm support 54 while the wrists are in a vertically neutral flexural condition. This substantially reduces the risk of RSI.

To provide comfortable, stable support for the forearms 56 the fore-arm support 54 has a depth "a" in a direction essentially transverse to a longitudinal direction of the field of alphanumeric keys of at least 20 cm, preferably 25-35 cm and most preferably about 30 cm. Furthermore, the fore-arm support 54 is padded with a resilient material.

A comfortable support of the fore-arm 56 is of particular importance, because only if the fore-arms are supported comfortably, the muscles for lifting the fore-arms 56 are effectively relaxed and the trapezius muscles in the neck area, of which the tension is related to the tension in the muscles for lifting the fore-arms 56, are effectively relaxed as well resulting in a markedly reduced sense of body tension.

The fore-arm support 54 has two fore-arm support portions 57 and a central portion 58 between the fore-arm support portions 57. This central portion 58 has a substantially smaller depth than the fore-arm support portions 57 for receiving a ventral portion of a user's body.

The fore-arm support 54 further includes recesses 59 closely adjacent the field of alphanumeric keys 52 for receiving lower portions of balls 60 of the thumbs 61 of a user. This further improves a comfortable neutral condition of the wrist during operation of the track balls 2, 3 the hand being in a position as the hand 62 at the left in Fig. 3. The recesses 59 further locate the ball 60 of the thumb 61, so that essentially no effort is required to keep the hand in position during operation of the track ball 2, 3 at the outside of the keyboard 1.

In order to support and locate the fore-arms 56 in a more elevated position during typing on the field of keys 52 as illustrated by the hand 63 at the right in Fig. 2, the fore-arm support 54 further includes ridges 64 oriented towards the field of alphanumeric keys 52 for supporting a user's hands 63 in a recess 65 directly adjacent the balls 60 of the thumbs 61 of that user. To reduce the amount of space occupied by the keyboard 1 on the desk while it is not being used or during tasks of a brief duration, the fore-arm support 54 is removably attached to a housing 66 of the keyboard carrying the field of alphanumeric keys 52. In attached condition, the fore-arm support 54 can also be used advantageously while the keyboard 1 and or the fore-arm support 54 is supported on the user's lap, on arm-rests of a chair or even on a bed or the floor.

To further enhance a relaxed and neutral condition of the hands and the wrists of a user, the row of the keys most proximal to a user in operating condition including interruptions 68, 69 forming support surfaces for supporting a user's thumbs 61. This feature is of particular advantage in combination with the enhanced support provided by the fore-arm support 54, but can also be employed advantageously in combination with otherwise conventional keyboards. The thumb supports 68, 69 allow the user to relax the muscles for moving the thumb, especially the extensor and abductor muscles of the thumb which are particularly prone to tendon sheath inflammation.

The keys of a row of the keys most proximal to a user in operating condition have a depth which is larger than the depth of at least keys of central rows of keys of the field 52 of alphanumeric keys. This is advantageous in that it provides an increased tolerance regarding the area where the thumb of a user is operative. The position of this area varies substantially depending on the size and shape of a user's hand and the preferred extent to which the fingers are flexed during typing.

From the above description and considerations, it will be apparent to the skilled person that the invention is not limited to the examples as shown but that within the framework of the invention as set forth in the claims many alternative embodiments and modes of carrying out the invention are conceivable.

It may for instance be preferred to provide that the functions of detecting and monitoring operating actions and generating control signals for influencing the user to change to alternative operating actions are performed by the computer to which the user interface is connected - preferably at the level of an operating system, i.e. after signals generated by the interface have been translated into standard instructions of the operating interface. Thus, the need of providing the operating interface with separate circuitry for detecting and monitoring operating actions is obviated. In connection with this, the signals for influencing the choice of alternative actions or types of action for inputting particular instructions are preferably displayed on the main display of the computer system or issued via sound generating facilities of the computer system.

Instead of by changing the visibility of characters on the keys, indicating whether a caps lock function or numeric lock function is activated can also be achieved in many other ways, such as by displaying signs or slight color flashes on the computer display in response to keys being operated in the caps lock or numeric lock operating modes, by generating different sounds if the keys are operated in the caps lock or numeric lock operating modes or by changing the resistance or pattern of resistance of keys being depressed in accordance with the active operating mode.

If two cursor and pointer operating devices are used, such as mousses, trackballs or touchpads, it is for instance also possible to provide separate devices for left-handed and right-handed operation or to provide the device with a sensor for detecting whether it is located to the left or to the right of the keyboard for detecting with which hand it is apparently operated.

Claims

Cl aims

1. A computer peripheral user interface system for manually inputting instructions to a computer, said interface system being operable for inputting at least one instruction by at least two alternative actions, including: detection means (2-25) for detecting use of said alternative actions or of types of action to which one or the other of said alternative actions are associated for inputting instructions to said computer; monitoring means (28) for comparing intensities of detected use of said alternative actions or of said types of action and for signaling too intensive use of one of said alternative actions or of said types of action; and influencing means (30-35) responsive to said monitoring means (28) for influencing a user to decrease relative use of one of said actions or of said types of action in favor of at least another one of said alternative actions or of said types of action in response to a signaled too intensive use of said one of said alternative actions or of said types of action.

2. A system according to claim 1, wherein said detection means (2-25) for are adapted for distinguishing between left-handed and right-handed execution.

3. A system according to claim 1 or 2, wherein said detection means (2-25) include distinct operating members (2-21, 50, 51) for operation by different ones of said alternative actions or of said types of action, said monitoring means (28) being adapted for comparing detected intensities of operation of said distinct operating members (2-21, 50, 51) . 4. A system according to claims 2 and 3, wherein at least one of said operating members (3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 51) is arranged for left-handed operation and at least one other one of said operating members (2,

4, 6, 8, 10, 12, 14, 16, 18, 20, 50) is arranged for right-handed operation .

5. A system according to claim 4, wherein said distinct left-hand operable and right-hand operable operating members (2-21, 50, 51) include at least operating members (2, 3) for controlling displacements of a pointer- or a cursor on a graphic display.

6. A system according to claim 4 or 5, wherein said distinct left-hand operable and right-hand operable operating members (2-21, 50, 51) are adapted for controlling mutually identical functions.

7. A system according to claim 5 or 6, wherein said distinct left-hand operable and right-hand operable operating members (2-21, 50, 51) include operating members (2, 3) having at least two-dimensionally operative operating surfaces .

8. A system according to any one of the claims 4-7, further including a keyboard (1) having a field (52) of alphanumeric keys, said distinct left-hand operable and right-hand operable operating members (2-21, 50, 51) being located in areas on opposite lateral sides of said field (52) of alphanumeric keys.

9. A system according to any one of the claims 4-8, wherein each of said distinct left-hand operable and right- hand operable operating members (2-21, 50, 51) include at least a numeric keypad (18, 19) .

10. A system according to claim 9, wherein said keys of said numeric keypads (18, 19) are each formed by a number of keys of said field (52) of alphanumeric keys, said numeric keypad being activated as an alternative function in addition to said alphanumeric function. _ -

11. A system according to claim 10, wherein the functional condition of said keys of said keypads (18, 19) is displayed on said keys in accordance with the active function of the respective keys.

12. A system according to claim 3, wherein said influencing means (30-35) include optical signaling means (34, 35) for signaling which one of said distinct operating members (2-21, 50, 51) for operation by different ones of" said alternative actions or of said types of action is to be used preferably.

13. A system according to claim 3, wherein said influencing means (30-35) include at least one control means (30) for temporary making at least one of said distinct operating members (2-21, 50, 51) for operation by different ones of said alternative actions or of said types of action inoperative .

14. A system according to claim 2, including a left- hand and right-hand operable operating member (53) , said detection means (2-25) including means (68, 69) for detecting whether said operating member (53) is operated left-handed or right-handed.

15. A system according to any one of the preceding claims, further including at least one cursor operating member (53) located m a central area of said field (52) of keys.

16. A system according to any one of the preceding claims, further including a keyboard structure (1) including a field (52) of alphanumeric keys, wherein said influencing means (30-35) are included in said keyboard structure (1) .

17. A system according to any one of the preceding claims, further including a keyboard structure (1) including a field (52) of alphanumeric keys and a fore-arm support (54) adjacent said field (52) of alphanumeric keys for supporting fore-arms (56) of a user.

18. A system according to claim 17, wherein said forearm support (54) is mounted such that projected continuations (55) of said fore-arm support (54) extend over said field (52) of alphanumeric keys spaced above said field (52) of alphanumeric keys.

19. A system according to claim 17 or 18, wherein said fore-arm support (54) has a depth in a direction essentially transverse to a longitudinal direction of said field (52)- of alphanumeric keys of at least 20 cm.

20. A system according to claim 19, wherein said forearm support (54) has two fore-arm support portions (57) and a central portion (58) between said fore-arm support portions (57), said central portion (58) having a substantially smaller depth than said fore-arm support portions (57) for receiving a ventral portion of a user's body .

21. A system according to any one of the claims 17-20, wherein said fore-arm support (54) includes recesses (59) closely adjacent said field (52) of alphanumeric keys for receiving lower portions of balls (60) of the thumbs (61) of a user.

22. A system according to any one of the claims 17-21, wherein said fore-arm support (54) includes ridges (61) oriented towards said field (52) of alphanumeric keys for supporting a user's hands in a recess (65) directly adjacent the balls (60) of the thumbs (61) of that user.

23. A system according to any one of the claims 17-22, wherein said fore-arm support (54) is removably attached to a housing of said keyboard (1) carrying said field (52) of alphanumeric keys.

24. A system according to any one of the preceding claims, further including a keyboard structure (1) including a field (52) of alphanumeric keys, a row of said keys most proximal to a user in operating condition including interruptions (68, 69) forming support area's for supporting a user's thumbs (61).

25. A system according to any one of the preceding claims, further including a keyboard structure (1) including a field (52) of alphanumeric keys, keys of a row of said keys most proximal to a user in operating condition having a depth larger than the depth of at least keys of central rows of keys of said field (52) of alphanumeric keys.

26. A method of guiding manual input of instructions to a computer by operating a computer peripheral user interface in which at least two alternative actions are available for inputting at least one instruction, including the steps of: detecting use of said alternative actions or of types of action to which one or the other of said alternative actions are associated for inputting instructions to said computer; comparing intensities of detected use of said alternative actions or of said types of action; signaling too intensive use of one of said alternative actions or of said types of action; and influencing a user to decrease relative use of at least said one of said alternative actions or of said types of action in favor of another one of said alternative actions or of said types of action in response to a signaled too intensive use of said one of said alternative actions or of said types of action.

27. A method according to claim 26, wherein said alternative actions or said types of action are distinguished by left-handed and right-handed execution.

28. A method according to claim 26 or 27, wherein said actions or types of action are distinguished by operation of distinct operating members (2-21, 50, 51), and wherein intensities of operation of said distinct operating members (2-21, 50, 51) are detected and compared.

29. A method according to claims 27 and 28, wherein at least one of said operating members (3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 51) is operated left-handed and at least one other one of said operating members (2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 50) is operated right-handed.

30. A computer readable data structure including a - computer program for guiding operation of a computer peripheral user interface system for manually inputting instructions to a computer, said interface system being operable for inputting at least one instruction by at least two alternative actions, including: registration instructions for registering use of said alternative actions or of types of action to which one or the other of said alternative actions are associated for inputting instructions to said computer; monitoring instructions for comparing intensities of detected use of said alternative actions or of said types of action and for signaling too intensive of use of one of said alternative actions or of said types of action; and influencing instructions responsive to said monitoring means (28) for generating guiding signals to a user to decrease relative use of at least said one of said alternative actions or of said types of action in favor of another one of said alternative actions or of said types of action, in response to a signaled too intensive use of said one of said alternative actions or of said types of action.