This invention relates in general to speech diagnosis therapy and, more specifically, to a tongue force measuring device for use in speech therapy.
Some speech pathologists feel that certain speech disorders stem from poor tongue strength in one or more directions of tongue movement. Treatment of the problem is usually attempted when the subject is a child. Attempts have been made to measure tongue strength using a load cell placed toward the middle of the tongue with the head restrained. Since the cell measured only mid-tongue strength in a single direction, the results were of limited value. This work was described by J. P. Working et al. in their article "Tongue Strength Part I: Following Total Laryngectomy" The Laryngoscope, 90 (1980), pp. 680-684. Other attempts to measure tongue strength use head restraints and cumbersome equipment which tend to frighten small children, detracting from validity of results.
A number of devices have been developed to detect linguapalatal contact during phonation by means of a pattern of spaced electrical contacts on an artificial palate. Typical of these are the devices described by Takinishi et al. in U.S. Pat. No. 4,310,002, Fletcher et al. in U.S. Pat. No. 4,112,596 and Hori in U.S. Pat. No. 4,287,895. While these provide information as to tongue location during speech which is useful in treating speech disorders, they provide no information on tongue strength or force in any particular direction during speech.
An oral strain gage is described by Davis et al. in U.S. Pat. No. 3,297,021. However, this device measures only pressure between the jaws during chewing or the like. Since the strain gage is embedded in an artificial tooth, it is incapable of measuring tongue force.
Thus, there is a continuing need for a device for measuring tongue force during speech in three dimensions while simultaneously being light, compact and suitable for use by children.