Occlusion pressure sensor

The disclosure relates to an occlusion pressure sensor of the construction in which pressure sensitive block changing in electric characteristic under external pressure are arranged in multiple rows. The occlusion pressure sensor is designed to detect an electric signal responsive to occlusion pressure from the pressure sensitive blocks by successively and electrically scanning the blocks in the state of a patient engaging his teeth.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to an occlusion pressure sensor and more 
particularly to an occlusion pressure sensor detecting occlusion pressure 
produced at occluding points of the teeth in terms of electric signal. 
2. Prior Art 
It is unquestionably important that proper adjustment of occlusion be made 
in dental treatment, and it was the conventional practice to determine 
whether occlusion is proper by having a patient bite occluding paper, 
similar to carbon paper in copying, an occluding ribbon, similar to an 
inked ribbon for typewriter, occluding wax, a thin wax sheet for shaping, 
and analyzing impressions of the teeth, namely the color transferred onto 
the occluding points or occluding surface of the teeth and strength of the 
color patterns of the decolorized portions by transfer of color onto the 
teeth, state of depression, etc. 
Although the method described above provides information on general 
occlusion pressure, it cannot provide the exact distribution of strength 
of occlusion pressure and can provide only the results of occlusion 
carried out once or of accumulation of occlusion effected several times. 
Accordingly, it was impossible to realize the progress of occlusion in 
terms of time from the state of the teeth beginning to make contact with 
each other to the state of strong occlusion. The knowledge of such 
progress of occlusion is also necessary for the examination of the initial 
contact considered important at the time of adjustment of dental 
occlusion. In addition thereto, it is no less necessary to analyze not 
only upper occlusion and lower occlusion, but also right and left and 
backward and forward slide at the time of adjustment of dental occlusion. 
Nevertheless, it was impossible in principle to examine such occlusion and 
slide simultaneously by the conventional practice using occluding paper, 
occluding ribbon and occluding wax. 
SUMMARY OF THE INVENTION 
Accordingly, it is an object of this invention to provide a pressure 
sensitive sensor capable of obtaining information on occlusion pressure 
produced at various points of occlusion in terms of an electric signal by 
a patient engaging the upper with the lower teeth simply in the mouth. 
It is a further object of the invention to provide a pressure sensitive 
sensor capable of providing a dentist with information on occlusion 
pressure produced at occluding points at real time in the state of a 
patient engaging the upper with the lower teeth in the mouth. 
It is still another object of the invention to provide a pressure sensitive 
sensor capable of providing information on changes in occlusion pressure 
in the course of time from the time that the teeth begin to make contact 
with each other to the time at which the teeth are brought into the state 
of strong occlusion. 
In the achievement of these objects, there is provided a pressure sensor 
for detecting occlusion pressure which comprises a complex pressure 
sensitive element consisting of a rectifying layer and a pressure 
sensitive layer, the element changing electric characteristic thereof in 
response to occlusion pressure by catching the occlusion pressure of the 
teeth an upside electrode and an underside electrode, the electrodes being 
constructed by arranging thin strip pieces or segments in such manner that 
the strip pieces or segments are arranged on the upper and lower surfaces 
of the element in regularly crossing or coordinated relation vertical of 
the complex pressure sensitive element so as to form a plurality of 
pressure sensitive blocks marked off from one another in the pressure 
sensitive element, and an insulating film, the film including the upside 
and underside electrodes and encircling and covering the complex pressure 
sensitive element.

DETAILED DESCRIPTION OF THE INVENTION 
A detailed description will now be given of embodiments of the sensor of 
the invention with reference to the accompanying drawings. 
FIG. 1 shows a thin plate-like complex pressure sensitive element 4 
constructed of a pressure sensitive layer 2 laminated over the underside 
of a rectifying layer 1, which pressure sensitive layer 2 changes electric 
characteristic thereof by being subjected to external pressure. FIGS. 2 
and 3 respectively show an arrangement of an upside and underside 
electrodes constructed in multiple row arrangement wherein longitudinal 
strip electrodes 50 . . . are provided in side-by-side relation spaced by 
insulating materials 71 . . . from one another. The reference characters 
a, b, c, d, . . . and 1, 2, 3, 4 . . . designated leading-in wires 
conducted from the strip electrodes 50 . . . . The leading-in wires, as 
shown in FIG. 10, are housed in one flat insulating tube, conducted out of 
an occlusion pressure sensor and adapted to conduct occlusion pressure 
signals in the form of electric signals generated by the occlusion 
pressure sensor to outside. 
According to the occlusion pressure sensor shown in the embodiment, the 
strip electrodes 50 . . . (5) are arranged and constructed on the upside 
of the complex pressure sensitive element 4 of the construction shown in 
FIG. 1, and strip electrodes 50 . . . (6) are arranged and constructed on 
the underside of the element 4 as shown in FIG. 3 so as to sandwhich the 
element between the electrodes (5) and (6) in the manner that the strip 
electrodes 50 . . . on the upside and the underside of the element are 
arranged and constructed in mutually three-dimensionally intersecting 
relation. Pressure sensitive blocks 51 . . . are constructed in three 
dimensionally duplicate portion of the strip electrodes 50 . . . on the 
upside of element 4 and the strip electrodes on the underside thereof with 
the element 4 sandwiched therebetween. The numeral 8 designates insulation 
covering that encircles and envelopes the pressure sensitive element 4. 
FIG. 4 is a longitudinal sectional view, broken in part, of the occlusion 
pressure sensor. 
FIG. 5 is a perspective view of another embodiment of the pressure 
sensitive element. The pressure sensitive blocks 51 according to this 
embodiment are constructed by both marking off a complex pressure 
sensitive element of the construction shown in FIG. 1 in lattice form by 
insulating members 71 . . . and by assembling a plurality of segment 
electrodes 50 . . . in regularly coordinated relation to both on the 
upside and on the underside of the thus marked-off portions. 
FIGS. 6 and 7 respectively show the arrangement of the upside and underside 
electrodes arranged on the upside and underside of the complex pressure 
sensitive element 4 shown in FIG. 4. In the figures, strip electrodes 50' 
. . . arranged on the upside and underside of the element 4 are 
respectively connected in series by thin conductors 72 . . . in each file 
or in each rank arrangement. 
FIG. 8 is a longitudinal sectional view, broken in part, of an occlusion 
pressure sensor wherein the numeral 8 designates an insulating film 
encircling and covering the complex pressure sensitive element 4 
constructed as above. 
In the two embodiments illustrated, so long as the rectifying layer 1 has 
the property of permitting the flow of current in one direction but 
preventing that of current in the opposite direction, the layer 1, 
irrespective of whatever material may form the layer, can be selected from 
all kinds of material or complex such as a selenium rectifying material of 
Se layer and a complex laminated material Fe consisting both of OdS layer 
and Ou.sub.2 S layer, a selenium rectifying material Al layer and Se 
layer, a cuprous oxide rectifying material comprising Cu layer and 
Cu.sub.2 O layer, a Schottky rectifying material having a film as of Au, 
Ni, W, Mo, V formed on the surface Si, Ge or GaAs layer and a 
semiconductor formed by P-N junction of Si or Ge semiconductor. A material 
usable as a pressure sensitive layer 2 may be the one 21 (such as 
vinylidene polyfluoride film (PVDF film), zirconium titanate film (PZT 
film)) or may be the one 22 that changes the electric resistance thereof 
in response to the external pressure applied (for example all materials 
such as pressure sensitive rubber possessed with pressure sensitivity by 
mixing metal or carbon particles into rubber, a film having a pressure 
resistant effect and in which a semiconductor such as Si is used, a cell 
containing carbon particles) and other complexes may suitably be selected 
so long as they change the electric characteristic thereof under external 
pressure, no matter whatever material they may be. On the other hand, the 
upside electrode 5 and the underside electrode 6 may be formed by directly 
vapor coating and metalizing an electroconductive metal as of aluminum and 
silver at suitable points on the respective sides of the pressure 
sensitive element 4 or may be formed separately by vapor coating or 
metalizing an electroconductive material such as aluminum and silver on an 
insulating substrate such as of ceramic and synthetic resin. In short, 
recourse may be had to any other means that is sufficient to constitute 
pressure sensitive blocks 51 . . . containing pressure sensitive element 4 
and marked off in lattice form. 
FIG. 9 is an equivalent typical electric circuit diagram showing electrical 
structure of the sensor of the invention, wherein the numerals 51 . . . 
designate pressure sensitive blocks and 1 designates diodes which show 
equivalently a rectifying layer. 
The structure of the sensor of the invention is electrically shown as a 
diode matrix of the type described above. The reference character SW1 
designates a switching mechanism for energizing and scanning the upside 
electrode 5 of the sensor constructed of strip or segment electrodes 50 . 
. . and 51' . . . and SW2 designates a switching mechanism for energizing 
and scanning the underside electrode 6 of the sensor constructed of strip 
or segment electrodes 50 . . . and 5' . . . , and E designates a DC power 
source used when a change in the electric characteristic of the pressure 
sensitive blocks 51 . . . represents a resistance change, and the source 
is considered unnecessary when a change in the electric characteristic of 
the pressure sensitive blocks 51 . . . represents a resistance change. 
A description will now be given of the use of the sensor of the invention 
and of the operating principle thereof with reference to the drawings. A 
user bites a sensor S by the upper and lower teeth in the mouth as shown 
in FIG. 10. In this state, all that is necessary to do is to electrically 
and scan all the pressure sensitive blocks 51 . . . and derive an electric 
signal responsive to occlusion pressure from the blocks 51 . . . . 
This derivation of electric signal is effected by switching switches SW1 
and SW2, and this switching operation may readily be made by use of an 
electronic switch. More specifically, during the time that the electrodes 
connected in each rank out of the upside electrode 5 are energized by 
switching operation of SW1 (to be referred hereinafter as rank-scanning), 
the electrodes connected in each rank out of the underside electrode 6 are 
energized successively (to be referred to hereinafter as file-scanning). 
By so doing, the pressure sensitive blocks 51 . . . arranged in lattice 
form are successively scanned and a change in electric characteristic 
effected by occlusion pressure is electrically converted into an electric 
signal output. FIGS. 11 and 12 respectively show time charts both for 
rank-scanning pulse and for file-scanning pulse in scanning of the kind 
described above. FIG. 13 is a diagram illustrating the occlusion pressure 
signal (pulse) outputted from the pressure sensitive blocks. In FIG. 9, 
the electric signal if converted into voltage and is conducted outside 
through a resistor R. Switching of switches from SW1 to SW2 is 
successively operated in synchronism with the horizontal and vertical 
scanning of CRT 30 provided in housing 31 to thereby lead the output 
signal of occlusion sensor S to a brilliance modulation circuit and 
indication of the output signal of CRT picture provides a picture of an 
occlusion pressure change in the teeth panoramically and at real time. 
In addition, the invention may be used in combination with a video tape 
recording device or graphic display equipment. It should be understood 
that combined use of other suitable devices makes it possible to provide 
information on occlusion pressure not only in the form of a moving image 
but also in the form of a still image. 
As described above, since the invention makes it possible to correctly 
detect an electric signal responsive to occlusion pressure in each 
pressure sensitive block, the invention is of great use to dental 
treatment in that it enables the operator to grasp the occlusion pressure 
distribution over the entire jaws more positively and at real time.