Method for selecting communication devices for non-speaking patients

• US 4,969,096 A
• Filed: 09/25/1989
• Issued: 11/06/1990
• Est. Priority Date: 04/08/1988
• Status: Expired due to Fees

• Current Assignee: Massachusetts Institute of Technology, New England Medical Center
• Original Assignee: Massachusetts Institute of Technology, New England Medical Center
• Inventors: Goodenough-Trepagnier, Cheryl, Rosen, Michael J.
• Primary Examiner(s): Smith, Jerry
• Assistant Examiner(s): Hayes, Gail O.
• Application Number:
  US07/412,579
• Time in Patent Office: 407 Days
• Field of Search: 128/630, 128/745, 434/112, 364/413.02, 364/413.01, 340/825.19
• US Class Current: 434/112
• CPC Class Codes: G09B 21/00 Teaching, or communicating with, the blind, deaf or mute audible presentation of material to be studied G09B5/04; devices or methods for replacing direct visual or auditory perception by another kind of perception A61F9/08, A61F11/04; audible indication of meter readings or of colour G01D7/12; watches for blind persons G04B25/02; speech analysis, speech recognition G10L; sound-recording or reproducing, per se G11B

Abstract

A computer-assisted method for prescribing communication devices for non-speaking patients which is objective, and is not device-limited and functions as an effective tool for clinicians prescribing communication devices. Because the method is not device-limited, it may also be used to test the effect of design changes in device characteristics which affect the fit of the device to the user and the communication rate achieved; and enables a direct comparison to be made among devices, based on scoring the user-device pair. The method comprises the compilation of data concerning client needs and preferences as well as the client cognitive and learning characteristics; assessing the patient'"'"'s motor abilities for control of devices; assessing the characteristics of a variety of communication devices; and using a computer program and specially developed formulas to integrate, compare, and assess the results so as to arrive at a communication device best suited for the client'"'"'s needs.

Claims

1. Method for prescribing a communication device for a patient with a neuromoter deficit affecting speech comprising:

assessing the patient'"'"'s motor abilities for control of a keyboard-type device, said motor ability assessing including measuring reach envelope ability, actuation force ability, and actuation accuracy ability;

assessing characteristics of each of a plurality of keyboard-type communication devices, said characteristics assessing including deriving an expert keystroke history for each said keyboard-type device for production of a sample text corpus; and

evaluating the results of each said assessing to prescribe a communication device for the patient.

2. The method of claim 1 wherein the step of deriving an expert keystroke history comprises:

determining the length of the longest unit of text in the language menu of said keyboard-type device,

selecting a sequence of characters from said sample text corpus equal in number to said longest unit length, and

attempting to match said selected characters to a unit of text in said language menu.

3. The method of claim 2 further comprising repeatedly dropping a character from said selected characters and attempting to match the resulting group of characters to a unit of text in said language menu until a match is found.

4. The method of claim 2 wherein said selecting commences with the leftmost characters from said sample text corpus, and continues through said text corpus until all character groups have been matched to units of text in said language menu.

5. The method of claim 1 wherein the results of each said assessing are entered into a computer and said evaluating is performed by said computer.

6. The method of claim 1 wherein said motor ability assessing includes automated data acquisition by a computer.

7. The method of claim 1 further comprising:

identifying a minimal motor ability operational requirement for each said keyboard-type communication device, and

excluding from consideration any said keyboard-type communication device for which the patient'"'"'s motor abilities fall below said minimal motor ability operational requirement.

8. The method of claim 7 wherein said minimal operational requirement for each keyboard-type communication device comprises:

requirement of an ability to move to the most distant key in each of a plurality of directions;

requirement of an ability to produce a minimum force at each key; and

requirement of an ability to touch a selected key while not touching adjacent keys.

9. The method of claim 1 wherein said reach envelope ability measuring comprises measuring the greatest distance the patient can reach in each of a plurality of directions.

10. The method of claim 1 wherein said actuation force ability measuring comprises measuring the largest force the patient can reliably exert at each position of greatest reach ability.

11. The method of claim 1 wherein said actuation accuracy ability measuring comprises measuring the smallest target size the patient can reliably touch when alternately touching each of a pair of targets at opposite locations of greatest reach ability.

12. The method of claim 1 wherein said keyboard-type motor abilities assessing comprises:

directing the patient to repeatedly move between two targets;

varying the target characteristics; and

measuring the time the patient takes to move between the targets for each combination of characteristics.

13. The method of claim 12 wherein said varying characteristics include:

distance between targets;

size of each target;

angular direction cf movement between targets;

force required to depress each target; and

travel of target required to depress each target.

14. The method of claim 13 wherein the performance speed is directly dependent on the accuation force and the travel of target.

15. The method of claim 12 wherein each said target is an electrical switch.

16. The method of claim 12 further comprising calculating a client'"'"'s motor determined maximum rate for each said keyboard-type communication device using said target characteristics and said time to move between targets.

17. The method of claim 16 wherein said motor determined maximum rate calculating comprises applying the results of said time to move between targets measuring to said optimized keystroke history.

18. The method of claim 1 further comprising:

assessing the patient'"'"'s cognitive abilities, and assessing

the patient'"'"'s sensory abilities.

19. The method of claim 18 wherein said cognitive assessing comprises assessing spelling, code learning and location learning abilities, and said sensory assessing comprises assessing vision and hearing abilities.

20. The method of claim 19 further comprising:

identifying a minimal cognitive and sensory operational requirement for each said keyboard-type communication device, and

excluding from consideration any said keyboard-type communication device for which the patient'"'"'s spelling, code learning, location learning, vision or hearing ability falls below said cognitive and sensory minimal operational requirement.

21. The method of claim 19 further comprising:

assessing the patient'"'"'s needs and preferences, and

combining each said motor determined maximum rate with said needs and preferences to determine an expected benefit from use of each said keyboard-type communication device.

22. The method of claim 21 further comprising:

determining a reference motor determined maximum rate and a reference expected benefit for at least one scanning-type communication device;

excluding assessing the patient'"'"'s motor abilities for controlling each scanning-type communication device if any of said keyboard-type devices yields both a greater motor determined maximum rate than said reference rate for all said scanning-type devices, and a greater expected benefit than said reference benefit for all said scanning-type devices; and

assessing the patient'"'"'s motor abilities for controlling each scanning-type communication device if any of said keyboard-type devices yields either the same or a lesser motor determined maximum rate than said reference rate for any of said scanning-type devices, or the same or lesser expected benefit than said reference benefit for any of said scanning-type devices.

23. The method of claim 21 further comprising:

determining said reference motor determined maximum rate for each said scanning-type communication device from assessment of at least one able-bodied person'"'"'s motor abilities in controlling said scanning-type communication device; and

determining said reference expected benefit for each said scanning-type communication device from the patient'"'"'s needs and preferences and said reference rate.

24. The method of claim 23 wherein said scanning-type motor abilities assessing further comprises:

directing the patient to close a switch twice;

measuring the time the patient takes to initially close the switch; and

measuring the time from the first switch closure to the second switch closure.

25. The method of claim 24 wherein the scanning rates are varied.

26. The method of claim 25 wherein said rates are varied in response to the patient'"'"'s prior scanning-type assessing measurements.

27. The method of claim 24 wherein each said switch is a paddle switch.

28. The method of claim 24 wherein each said switch is a breath pressure switch.

29. The method of claim 24 further comprising calculating a motor determined maximum rate for each said scanning-type communication device using the results of said time measuring.

30. The method of claim 29 wherein said motor determined maximum rate calculating comprises:

deriving a scan interval history for production of at least one sample text; and

applying the results of said time measuring to said scan interval history.

31. The method of claim 30 wherein the results of said time to switch closure measuring and said time to switch release measuring are used to calculate said motor determined maximum rate for each said scanning-type device which operates in dwell mode.

32. The method of claim 30 wherein the results of said time to initial switch closure measuring and said time from first switch closure to second switch closure measuring are used to calculate the motor determined maximum rate for each said scanning-type device which does not operate in dwell mode.

33. The method of claim 29 further comprising:

combining each said motor determined maximum rate with the patient'"'"'s needs and preferences to determine the expected benefit to the patient from use of said scanning-type communication device.

34. The method of claim 21 wherein said scanning-type motor abilities assessing comprises:

directing the patient to close and release a switch;

measuring the time the patient takes to close the switch; and

measuring the time the patient takes to release the switch.

35. The method of claim 19 wherein said code learning ability assessing comprises:

directing the patient to learn an association between codes and sets of words, and

testing the learning of said association.

36. The method of claim 35 wherein said association learning comprises:

learning association between a single digit code and each of three words,

learning association between a two digit code and each of five words, and

learning association between a two digit code and each of seven words.

37. The method of claim 19 wherein said location learning ability assessing comprises:

directing the patient to learn an association between locations and groups of letters, and

testing the learning of said association.

38. The method of claim 19 wherein said spelling ability assessing comprises:

placing letters of the alphabet into areas,

communicating a word to the patient, and

directing the patient to indicate in sequence each of said areas which contains letters for the proper spelling of said word.

39. The method of claim 1 further comprising assessing the patient'"'"'s motor abilities in controlling an encoded-type device using body-distributed switches.

40. The method of claim 39 wherein said encoded-type motor abilities assessing comprises:

directing the patient to alternately make at least one pair of switch closures; and

measuring the time between the first switch closure and the second switch closure.

41. The method of claim 40 wherein said switch closures are made with a single switch and the patient is directed to Close said single switch at least twice.

42. The method of claim 40 wherein said switch closures are made with at least one pair of switches and the patient is directed to alternate closures between said switches.

43. The method of claim 40 wherein the patient is directed to close a plurality of pairs of switches and the time between each closure is measured.

44. The method of claim 40 wherein the sequence and pairs of switch closings is varied.

45. The method of claim 40 further comprising calculating a motor determined maximum rate for each said encoded-type communication device using the results of said time between switch closure measuring.

46. The method of claim 45 wherein said encoded-type motor determined maximum rate calculating comprises:

deriving a switch closure frequency history for production of at least on sample text; and

applying the results of said time between closure measuring to said switch closure frequency history.

47. The method of claim 46 further comprising:

assessing the patient'"'"'s needs and preferences, and

combining each said encoded-type motor determined maximum rate with the patient'"'"'s needs and preferences to determine the expected benefit to the patient from use of said encoded-type communication device.

48. Method for prescribing a communication device for a patient with a neuromoter deficit affecting speech, which method utilizes a single input switch connected to a computer screen consisting of an upper row comprising a series of box outlines wherein one of said boxes is filled in with a target, and a cross hair cursor controlled by the switch and capable of moving across a bottom row on the screen in the manner of a one dimensional scanner, said method comprising:

closing and releasing the switch as quickly as possible when the cursor matches the target, whereby the response timeduring a single strike and the dwell time or closure-to-release time is measured;

closing the switch twice as quickly as possible when the cursor matches the target;

repeating both of said steps at decreasing scanning intervals until the client can no longer successfully complete the task;

increasing the scanning interval to the last successful scanning interval, and decreasing said interval in smaller steps than previously until the client fails for a second time to perform the task, whereby the response time during a repeated strike as well as the time between successive switch closures is measured.

49. Method for prescribing an encoded type of communication device for a patient with a neuromoter deficit affecting speech, utilizing on/off switches affixed to various parts of the patient'"'"'s body, comprising:

sequentially closing a pair of randomly designated switches;

measuring the time between closure of one switch and closure of the second switch in the pair;

repeating the performance until combinations of switching pairs have been exhausted;

determining the average values of the closure to closure times for all pairs of switches;

calculating a motor determined maximum rate for each of said encoded communication devices using the frequency with which switch closure at each input jack is followed by closure at all other input jacks and the closure-to-closure time required for each switch pair.