GB1562131A

GB1562131A - Artificialpalate for use in dynamic palatographical speech research and method of fabricating the same

Info

Publication number: GB1562131A
Application number: GB40292/77A
Authority: GB
Original assignee: Rion Co Ltd
Current assignee: Rion Co Ltd
Priority date: 1976-09-29
Filing date: 1977-09-28
Publication date: 1980-03-05
Also published as: FR2366001A1; DE2743440C3; FR2366001B1; DE2743440A1; SE416685B; DE2743440B2; SE7710814L

Description

(54) ARTIFICIAL PALATE FOR USE IN DYNAMIC PALATOGRAPHICAL SPEECH RESEARCH AND METHOD OF FABRICATING THE SAME (71) We, RION CO., LTD., a corporation organised under the laws of Japan of 20-41, Higashimotomachi 3-chome, Kokubunji-shi, Tokyo, Japan, do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to artificial palates for use in dynamic palatographical speech research and methods of making the same.

Dynamic palatography is the science of electrically detecting contacting modes of the human tongue with the palate during sheech in the form of momentary patterns and continuously observing such patterns. Movements of the tongue during speech are the basic factor of articulation and dynamic palatography performs a great role in articulatory improvements of speech and hearing disorders by utilizing the observation of physiological movements of the tongue.

The artificial palate to be used in dynamic palatography should be designed to fit intimately with the palate of an individual for whom it is intended and comprises many fine sensing electrodes distributed in a main palate body made of an insulating material such as a synthetic resin and lead wires connected to these sensing electrodes. In dynamic palatographic observation the lead wires are led out of the individual's mouth and connected to a palatography device, a low pulse voltage being applied to the tongue from outside through a part of the individual's body such as an earlobe or the like and patterns of the sensing electrodes to which an electric current flows through the tongue by physical contact between the tongue and the artificial palate or, in other words, between the tongue and the sensing electrodes during speech are detected and indicated to allow the continuous observations of the momentary contact patterns of the tongue.

Conventionally, in fabricating the artificial palate, as shown in Figs. 1 and 2, a plaster mould of the palate of an individual for whom an artificial palate is intended is taken and an instantaneously polymerizable resin in a molten state is poured over this plaster mould on its outer surface which has been brought into contact with the user's own palate to make a shell body 1 of a thickness of about 0.5 mm. At this time, a pair of wires 2 of a diameter of about 0.5 mm. to be wound on the outer peripheries of inner teeth of the user for holding the artificial palate are embedded in the shell at one end in and extend at their other ends from both side ends of the body 1. Then, many holes are made in any desired distribution at suitable intervals over the entire surface of the body, sensing electrodes 3 each made of a gold chip of a diameter of about 1 mm. are fitted and fixed respectively in these holes, and then lead wires 4 are connected to the respective sensing electrodes 4 on the other inner surface of the body which is to be contacted by the user's tongue. The lead wires 4 are insulating coated, bonded along the inner surface of the body 1 and collected at both side ends of the body in the form of lead wire bundles 5. The lead wire bundles 5 are led out of the user's mouth along the outsides of the upper teeth and the ends of lips. It is in consideration of undesirable troubles caused by inonization that gold is selected for the material of the sensing electrodes.

The artificial palate made by such a conventional technique as described above is finished by filing after the sensing electrodes are placed so that the inner surface of the body 1 which is to be contacted by the tongue as well as the exposed surface of the respective sensing electrodes 3 will be flush with each other. Thus many steps and a considerable amount of skill have been required.

Further, it has been difficult to treat many lead wires and there have been problems that mis-wiring and unfavourable conductions are likely to occur. As the wires for holding the palate body are wound on the inner teeth, the fitting of the artificial palate has caused some discomfort to the user and the lead wire bundles may be bitten to impair or even damage them during speech.

The present invention aims to avoid the above-mentioned defects and to provide an artificial palate wherein improved means for holding the palate body and means for leading out wire bundles are employed, whereby the unpleasant feeling during use as well as the risk of damaging the lead wires are effectively reduced.

According to the invention, there is provided an artificial palate for use in dynamic palatographical speech research, which comprises a shell body made of electrically insulative material to be intimately fittable to an individual user's palate, a plurality of sensing electrodes provided on a surface of said shell body to be in contact with the user's tongue when used, lead wires connected at one end to respective sensing electrodes and led out at the other end through an end part of the shell body, and means for mounting the artificial palate in a user's mouth, said sensing electrodes and lead wires being provided on a flexible and electrically insulative base board prepared separately from said shell body and secured beneath said tongue contacting surface and said lead wires being formed on at least one surface of said base by means of a printing circuit technique.

Preferably, the said mounting means comprises said led out ends of the lead wires which are coated with an electrically insulative material.

The sensing electrodes are preferably arranged on the base board in a matrix formation so that the labour required to wire the lead wires can be saved and the electric current flowing through the human body can be reduced to a minimum.

Substantially one half of the lead wires may be provided on one surface of the base board and the other half of the lead wires on the other surface of the base board.

The present invention also provides a method of making an artificial palate for use in dynamic palatographical speech research which comprises the steps of preparing a printed circuit board having on a flexible and electrically insulative base board a plurality of sensing electrodes and lead wires thereof, mould forming a shell body of an electrically insulative material to conform to an individual user's own palate, joining said printed circuit board intimately to said shell body on the side which is to be in contact with the user's tongue when used, and applying an electrically insulative coating to the joined printed circuit board on its surface to be in contact with the user's tongue while exposing the sensing electrodes.

The invention will now be further described, by way of example, with reference to the drawings, in which: Figure 1 is a plan view of a frame body of a conventional artificial plate; Fig. 2 is a perspective view of a completed artificial palate using the frame body of Fig.

1; Fig. 3 is a plan view of one surface of a printed circuit board used in an embodiment of the artificial palate according to the present invention; Fig. 4 is a plan view of the other surface of the printed circuit board shown in Fig. 3; Fig. 5 is a plan view of the first surface of the printed circuit board shown in Fig. 3 but with lead wires assembled; Fig. 6 is a plan view of an artificial palate completed with the printed circuit board shown in Figs. 3 to 5 according to the present invention; Fig. 7 is a schematic block diagram showing a generally utilized dynamic palatography observation system; Fig. 8 is a perspective view of another embodiment of an artificial palate according to the present invention; Fig. 9 is a diagram showing a sensing electrode arrangement and its wiring circuit for the artificial palate in another embodiment according to the present invention; Fig. 10 is an enlarged plan view of a pair of the sensing electrodes employed in the embodiment shown in Fig. 9; Fig. 11 is a diagram showing wave forms of signals used in operating the embodiment shown in Figs. 9 and 10; Fig. 12 is a fragmentary diagram showing still another embodiment of sensing electrode arrangement using both point-shaped and strip shaped sensing electrodes according to the present invention; Fig. 13 is a fragmentary plan view showing a further embodiment of sensing electrode arrangement using the strip-shaped sensing electrodes according to the present invention; and Fig. 14 is a plan view of a still another embodiment of the artificial palate on its surface designed to be in contact with the user's palate according to the present invention.

Referring to the first embodiment of the present invention with reference to Figs. 3 to 6, a printed wiring circuit made of, for example, a copper foil of a thickness of 18 to 35 microns is provided on each of two surfaces of a flexible and electrically insulative base board 10 made of, for example, a polyester or polyimide film of a thickness of 25 microns, and this base board 10 is prepared in a flat state but having an outline-and area adapted to any user's palate. A plurality of through holes 11a and 11b are made in the positions in which sensing electrodes are to be arranged. These holes are usually distributed symmetrically over the entire area of the board including its central and both side regions with a maximum total number of about 64 holes but the distribution pattern and total number of the holes may be properly selected as desired. Electrically conductive wires 1 3a and 1 3b leading from these holes towards a peripheral part of the board 10 are provided by means of a printing technique preferably on the respective surfaces of the board 10 divided substantially into halves with respect to the holes 11a and 11b as identified in Figs. 3 and 4 and also, on each of the surfaces, as divided into right and left groups with respect to further each one half of the respective groups of the holes 11 a and 1 lib as seen in Figs. 3 and 4. Such two groups of the wires 13a or 13b on each surface of the board 10 are respectively led towards two straight edges of the board, where they are connected to respective terminals 12a or 12b also printed in arrays adjacent the edges on each surface of the board, as shown in Figs. 3 and 4. For the printing technique of the wires 13a and 13b as well as the terminals 12a and 12b, it is preferable to employ, for example, an etching and through-hole plating technique. On the base board 10 on which the wiring and their terminals are thus provided, as shown in Fig. 5, sensing electrodes 14 are then fitted in the respective holes lla and 1 1b and insulation-coated lead wires 15 are fused and connected at their end parts to the terminals 12a and 12b to complete a print circuit board 17 for the artificial palate.

Reference numeral 16 indicates a sleeve covering each of a pair of bundles 15a of the lead wires 15.

It will be appreciated that several kinds of sizes of the printed board 17 are prepared so that they can be selectively used for all individuals, whereby a mass-production of the artificial palate is made possible.

While in the above described embodiment the wirings from the sensing electrodes to the terminals are provided as divided into halves on the respective surfaces of the printed board, it will be also appreciated that the whole wirings can be provided only on one surface of the board.

Now, in order to prepare a main body of the artificial palate, a plaster mould of the palate of an individual user is taken very precisely over the entire area of the user's palate to the extent of the teeth and gums.

Then, an instantaneously polymerizable resin in molten state is poured into this plaster mould to form a thin shell-shaped main body of a size covering the palate area surrounded by the teeth. In this case, such substance as an acrylate or silicone is preferably used for the instantaneously polymerizable resin.

Then, the above-described printed circuit board 17 is intimately joined on its one surface to the inner surface of the main body which is to be contacted by the tongue by such means as a gluing or the like. Since the base board 10 of the printed circuit board 17 is a flexible film, it will easily and intimately conform to the inner surface of the main body which is concavely curved. Further, to the other surface of the printed board thus joined, the same kind of the instantaneously polymerizable resin is applied to cover the surface integrally therewith.

Further, extended parts of the lead wires 15 and lead wire bundles 15a in the sleeves 16 are also coated with the same instantaneously polymerizable resin to be contiguous to and integral with the main body while being curved at their tips in outward directions of the mouth to form spaces 18 fitting the teeth at both sides of the mouth for holding them with arms 19 in which the lead wires are embedded, as shown in Fig. 6.

Finally, the thus joined assembly of the board 17 and main body is taken out of the plaster mould and is finished with a file to remove any fins and to smooth the surface on which the tongue is to contact the sensing electrodes so that an artificial palate 20 will be completed.

As described above, according to the present invention, the printed circuit board on which the sensing electrodes are arranged and their lead-out wirings are provided is formed as embedded in the form of a sandwich within the main body, so that the artificial palate can be fabricated easily and reliably without causing any risks of mis-wiring during the fabrication and of wire damage during use.

Further, as the holding arms 19 for mounting the device to the user's palate are provided by utilizing the parts including the lead wire bundles to be led out of the mouth, an unfavorable mounting feeling can be reduced and the problem of the lead wires being broken by biting can be eliminated.

In Fig. 7, there is shown a dynamic palatography operational system, in which a signal source 21 is connected to a signal electrode 22 in the form of a screw type metallic earring which is fitted to an earlobe 23 of the user through an electrically conductive paste for achieving reliable conduction. Electric signals will thus flow through the user's body from the earlobe 23 to reach his tongue 24.

Numeral 25 indicates an artificial palate in which many sensing electrodes 26 are distributed.

When the user speaks, his tongue 24 contacts the sensing electrodes 26 so that the signals will flow into the contacted sensing electrodes and corresponding ones of a plurality of comparators 27 connected to the respective sensing electrodes will operate to light corresponding indicating lamps 28.

Numeral 29 indicates a comparing voltage source which distributes a voltage to the respective comparators so that, as the signal current fed through the earlobe is also flowing through saliva to the electrodes even when the tongue is not in contact with any sensing electrodes, the comparator will operate only when a signal larger than that of the signal current comes in through saliva.

In performing observation with the above system, however, there has been a problem that, even if electric conduction of the signal electrode 22 fitted to the earlobe 23 is of several 10 KIl the conducting state of the conductive paste will vary so as to be of a resistance value of several 100 Kfl during the observation and the S/N ratio of the detected value when the tongue is not in contact with the sensing electrodes 26 to that when the tongue is in contact with them will be reduced.

According to the present invention, there is suggested as shown in Fig. 8 another embodiment for eliminating the defect above described. As shown in Fig. 8, a signal electrode 32 made of a conductive material such as a metallic foil is provided at a part of the arificial palate 30 on the surface 31 to be in contact with the user's palate, that is, on the opposite side to the one on which the sensing electrodes are disposed.

With this arrangement, the signal electrode 32 will be brought into direct contact with the user's own palate in the state of being wet and the contact resistance can be reduced to several KIl up to several 10 KIl.

Further, the conductive conditions during the observation will vary little and thus will be stable, whereby the S/N ratio will improve and the comparing voltage source 29 can be made simply and easily adjustable.

A further embodiment of the artificial palate according to the present invention wherein the sensing electrodes are provided in the form of a matrix will now be described with reference to Fig. 9 in which 64 pairs of the sensing electrodes are disposed in a matrix formation with 8 pairs in the longitudinal direction and 8 pairs in the lateral direction.

Each of these sensing electrodes has a pair of contact elements 41 and 41', 42 and 42', .....

which are arranged adjacent to one another at a small spacing between them, forming a pair of switch contacts, and lead cottons L and L1 are connected to the respective contact elements as shown in Fig. 10. As shown in Fig. 9, such sensing electrodes have respective left side contact elements 41, 49, ..... connected in parallel in the vertical direction and respective right side contact elements 41', 42', 43', connected in parallel in the horizontal direction and have their lead wires led out respectively to terminals A, B, C, H and a, b, e, h. Therefore, whereas 64 lead wire have been hitherto required if 64 electrodes are disposed in an artificial palate, it is possible to reduce the number of lead wires to only 16, according to this embodiment.

Further, in the embodiment of Fig. 9, the lead wires to the terminals A, B, H are respectively shunted through a resistance R to driving terminals A', B', C' H' for connecting thereto a driving source. When a signal P and a signal Q as shown in Fig. 11 are respectively given to a driving terminal A' and a "horizontal" terminal a, a signal shown by S of Fig. 11 will be detected at the terminal A if the contact elements 41 and 41' of the sensing electrode are short-circuited with each other.

When a signal T is given to the terminal A' and a signal U is given to the terminal a and the tongue is not in contact with the sensing electrode, a signal V will be detected at the terminal A.

That is, when the signals are given to the terminals A' and a, depending on whether the pair of switch contacts respectively forming the sensing electrode is ON or OFF, respectively different signals will be detected at the terminal A which forms a detecting terminal. Therefore, when signals given to the driving terminals A', B', C', H' and "horizontal" terminals a, b, c, h are dynamically driven, the opening and closing states at respective intersections in the matrix will be able to be detected at the "vertical" detecting terminals A, B, C, H.

Such a matrix formation as described above wherein multipolar sensing electrodes are employed is not limited solely to the particular arrangement shown in Fig. 9, but any other type of matrix formation may be utilized. For example, as shown in Fig. 12, a plurality of strip-shaped electrodes 111 may be provided in parallel in one direction and point-shaped electrodes 112 may be arranged adjacent them. In another embodiment shown in Fig. 13, a plurality of stripshaped electrodes 121 are arranged to be intersected vertically and horizontally with insulators interposed in the intersecting contact parts and the same effects will be obtained.

Now, in conventional artificial palates there has been the problem of an induced hum potential and such induced hum has been removed by making a part of the user's body an earth potential. According to the present invention, the trouble by the induced hum potential is removed by providing an earth electrode 132 made of a metallic lamina or the like as shown in Fig. 14 on the surface of the artificial palate 131 opposite to the surface having the sensing electrodes in such matrix formation as above.

With the arrangement shown in Fig. 14, the artificial palate can be used without any separate means for making the user's body at earth potential, while concurrently establishing the earth potential of the user's body at the same time. Thus, such problem as forgetting to earth the user's body will not occur.

As has been described above, the present invention has remarkable effects that the artificial palate can be easily and economically produced and the electric current flowing through the user's body can be reduced to a minimum.

WHAT WE CLAIM IS: 1. An artificial palate for use in dynamic palatographical speech research, which comprises a shell body made of electrically insulative material to be intimately fittable to an individual user's palate, a plurality of sensing electrodes provided on a surface of said shell body to be in contact with a user's tongue when used, lead wires connected at one end to respective sensing electrodes and led out at the other end through an end part of the shell body, and means for mounting the artificial palate in a user's mouth, said sensing electrodes and lead wires being provided on a flexible and electrically insulative base board prepared separately from said shell body and secured beneath said tongue contacting surface and said lead wires being formed on at least one surface of said base board by means of a printing circuit technique.

2. An artificial palate according to claim 1, wherein said mounting means comprises said led out ends of the lead wires which are coated with an electrically insulative material.

3. An artificial palate according to claim 1 or claim 2, wherein said sensing electrodes are arranged on said base board in a matrix formation.

4. An artificial palate according to any preceding claim, wherein each of the sensing electrodes comprise a pair of contactor elements.

5. An artificial palate according to any preceding claim, wherein substantially one half of said lead wires is provided on one surface of said base board and the other half of the lead wires is provided on the other surface of the base board.

6. An artificial palate according to any preceding claim, wherein an earthing electrode is provided on the surface of said shell body designed to be in contact with the user's palate.

7. An artificial palate substantially as described herein with reference to Figs. 3 to 14 of the drawings.

8. A method of making an artificial palate for use in dynamic palatographical speech research which comprises the steps of preparing a printed circuit board having on a flexible and electrically insulative base board a plurality of sensing electrodes and lead wires thereof, mould forming a shell body of an electrically insulative material to conform to an individual user's own palate, joining said printed circuit board intimately to said shell body on the side which is to be in contact with the user's tongue when used, and applying an electrically insulative coating to the joined printed circuit board on its surface to be in contact with the user's tongue while exposing the sensing electrodes.

9. A method of making an artificial palate substantially as hereinbefore described.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. separate means for making the user's body at earth potential, while concurrently establishing the earth potential of the user's body at the same time. Thus, such problem as forgetting to earth the user's body will not occur. As has been described above, the present invention has remarkable effects that the artificial palate can be easily and economically produced and the electric current flowing through the user's body can be reduced to a minimum. WHAT WE CLAIM IS:

1. An artificial palate for use in dynamic palatographical speech research, which comprises a shell body made of electrically insulative material to be intimately fittable to an individual user's palate, a plurality of sensing electrodes provided on a surface of said shell body to be in contact with a user's tongue when used, lead wires connected at one end to respective sensing electrodes and led out at the other end through an end part of the shell body, and means for mounting the artificial palate in a user's mouth, said sensing electrodes and lead wires being provided on a flexible and electrically insulative base board prepared separately from said shell body and secured beneath said tongue contacting surface and said lead wires being formed on at least one surface of said base board by means of a printing circuit technique.