Exploratory device with potting material

In a device with an elongate housing for examining the gums of a patient, with the housing having a connecting area for connecting a replaceable, movable exploratory tip and with mechanical and/or electronic detection elements provided in the housing for detecting and converting the movements of the exploratory tip. The invention proposes that the detection elements be designed to be liquid-tight and/or liquid-resistant, and surrounded by a potting compound inside the housing.

BACKGROUND OF THE INVENTION 
The invention relates to an exploratory device for examining the oral 
cavity of a person. Devices of this kind are known in the art and 
described for example in DE 44 38 603 A1. 
Prior art exploratory devices general comprise an elongate housing having a 
connecting area for connecting a releasable movable exploratory tip. The 
housing includes a mechanical or electronic element for detecting and 
converting movements of the exploratory tip into usable signals. These 
prior art devices are generally constructed such that the electronics 
located inside the housing RE temperature-resistant, so that the entire 
exploratory device can be sterilized at temperatures of for example 
134.degree. C. to 156.degree. C. 
An object of the present invention is to provide an improved exploratory 
device that is relatively easy to handle, relatively sturdy and relatively 
safe to operate. 
SUMMARY OF THE INVENTION 
The present invention provides an exploratory device that employs a potting 
material that is configured to cover the detection or conversion circuit 
or element(s) located in a housing of the device. For this purpose, the 
detection structure is either designed to be liquid-resistant, for example 
electronic components that can be surrounded directly by the potting 
compound, or is designed to be liquid-tight, for example a small tube that 
receives a spring and into which a mechanical transmission rod can extend 
that transmits the movement of the exploratory tip. 
By potting the electronic or mechanical assemblies (e.g., the detection 
structure) provided in the housing, they are effectively protected against 
entry of the sterilizing atmosphere so that adverse effects on the 
mechanical or electrical components during sterilization can be reliably 
prevented. In addition, the potting compound further provides improved 
mechanical stability against blows or impacts or the like on the housing, 
such as those that occur if the device inadvertently falls to the floor. 
Another advantage of employing the potting compound is that it allows the 
device to be sterilized directly without further protective measures, and 
therefore does not have to be sterilized in a special sheath for example, 
so that the handling of the device is facilitated and simplified. In 
addition, the potting compound forms a protective jacket about the 
detection components to protect them against contamination, thus making 
the device more robust and less prone to damage. 
Provision can be made for initially potting the above-mentioned components 
and then inserting the entire unit into the housing. This unit can then be 
provided with elastic outer projections that permit insertion into the 
housing against a certain resistance. The projections thus provide a 
shock-absorbent mounting of the unit inside the housing. Further provision 
can be made for the potting compound to extend up to the inside wall of 
the housing. 
Alternatively, provision can be made for potting the housing components in 
the housing itself, i.e. after they have been inserted into the housing, 
with the remaining space being filled by a potting compound, so that the 
potting compound extends up to the inside wall of the housing and forms a 
connection with it as by gluing. Thus, gaps and spaces within the housing 
can be filled with the potting compound, thus eliminating potential 
contamination sites, which are undesirable despite the apparent ability to 
sterilize them with known techniques. 
The potting compound can advantageously consist of two components so that 
reliable curing of the potting compound can be ensured even without air 
being admitted inside the housing. Very thin compounds are advantageously 
used for this purpose, so that remaining air inclusions can be eliminated 
and the space between the detection means located in the housing and the 
housing itself can be filled reliably and completely. 
The exploratory device according to the invention has one or more buttons 
by which the evaluation and storage electronics can be controlled. 
According to the invention, the buttons are advantageously provided with 
replaceable button caps that extend through the housing. The 
replaceability of the button caps makes it possible to remove the button 
caps at certain intervals and to clean thoroughly the cavities located 
beneath the button caps. 
Advantageously the button cap can have a barbed projection, for example, in 
the shape of a circumferential edge that tapers conically, to facilitate 
insertion of the button cap into an opening in the housing. When the 
button cap is subsequently removed from the housing, deliberate damage to 
the button cap projection is caused thereto by the shape of the housing, 
so that button caps, once removed, cannot be reused. In this fashion, a 
seal that is as dirt-tight or contamination-proof as possible can be 
provided between the button cap and the housing, and new button caps can 
be installed exclusively in the housing. 
An insertion device for installing the button cap can be provided in the 
form of a small tube that tapers conically, into which tube the button cap 
is inserted at the top, with the small tube extending into the opening in 
the housing. The button cap is then inserted into the small tube using a 
pusher, compressing the button cap and reducing its diameter so that the 
lower barbed projection on the button cap can be brought into a vacant 
space in the housing where it then expands again. The mounting tube can 
then be removed from the housing. Depending on the material properties of 
the button cap, provision can be made for allowing the newly installed 
button cap to be left alone for approximately 12 to 24 hours so that it 
can expand once more and slowly resume its original shape so that 
permanent seating of the button cap inside the housing is guaranteed. 
The button cap can be advantageously made hollow so that it is easier to 
deform when it is inserted into the housing opening in the manner 
described above. In its interior it can accept a plunger made of an 
elastomer material, for example in the shape of a rubber rod, with this 
plunger serving to transmit the pressure to the probe provided inside the 
housing. The probe can be made using SMD technology, so that even when a 
sterilizing atmosphere penetrates the housing along the circumference of 
the button cap, the components located inside the housing remain 
functional. Because of the small structural dimensions of the probe, the 
plunger ensures functionally reliable operation of the probe when pressure 
is exerted on the button cap, since the rubber rod is located centrally in 
the button cap and hence centrally above the probe. Pressure on an area 
sufficient for reliable triggering of the probe can then be reinforced by 
the fact that the plunger tapers conically at its lower end adjacent the 
probe. 
The potting compound and the avoidance of closed cavities inside the 
housing also advantageously ensure that partial areas of the device do not 
burst under sterilization conditions, as might otherwise be the case if 
there were air inclusions. A cavity that is free of potting compound and 
allows access to the probe for its operation is provided above the probe. 
Alternatively, other operating possibilities can be used to keep the 
housing free of button knobs or similar actuating elements. Thus, an 
especially slender rod-like housing can be created that allows especially 
good access to the back teeth of a patient, so that the handling process 
is more comfortable for the patient and the aperture angle of the mouth 
required under these conditions can be kept smaller. For example, adjacent 
the exploratory tip, the housing of such a device that does not have a 
button can have an external diameter of only 8 mm over a length of 5 to 10 
cm. 
In a known design of similar dental instruments, provision can be made for 
the wire- or rod-shaped area of the exploratory tip to have two bends 
provided at a distance from one another, with the bends being in opposite 
directions, so that the overall result is not a J- or L-shaped bend but 
one that is approximately Z- or S-shaped and is provided in the portion of 
the exploratory tip that is in the form of a wire or small tube. In this 
way, additional assurance is provided that an examination behind the teeth 
of the patient can be performed without difficulty by being suitable for 
use with aperture angles of the mouth that are as small as possible. 
The data acquired by the electronic or mechanical components can thus be 
stored advantageously with computer support, with the corresponding 
evaluation and storage electronics being provided in simple fashion in a 
so-called "organizer," such as a personal digital assistant (PDA) 
approximately the size of a hand, computer, or other processor. Such 
organizers are usually provided with interfaces that provide simple wired 
or wireless data transmission to larger computer systems. In addition, 
such PDA organizers accommodate the CPU of the computer, the keyboard, and 
a screen in a comparatively tiny space, so that this very compact unit can 
be covered in simple fashion by a transparent film and protected against 
contamination caused for example by spray from the patient's mouth. In 
view of the compact dimensions of such an organizer, this hygienic 
protection can be provided much more simply than if a computer with a 
modular design were employed, in which the CPU, keyboard, and screen 
constitute three separate assemblies connected with one another by cables. 
In addition, a PDA organizer has the advantage of ease of transportability, 
so that a doctor can always have the organizer with him in various 
treatment rooms and can avoid the cost-intensive use of a different 
computer in each individual treatment room. This mobility also allows data 
acquisition outside the doctor's treatment rooms, for example when the 
doctor visits patients confined to bed at home or in a hospital.

DESCRIPTION OF ILLUSTRATED EMBODIMENT 
FIGS. 1 through 3 illustrate a housing 1 that is generally approximately 
tubular or cylindrical in shape, and which can have changing diameters, 
FIG. 1, or even be composed slightly convex, conical, or with a polygonal 
cross-section. The elongate slender shape of the housing 1 facilitates 
handling of the device during use. 
As illustrated in FIG. 3, the housing 1 mounts acquisition structure 2 for 
acquiring and possibly transmitting movement of an exploratory tip 9 with 
a movable sensor point 10, which is connected to the housing 1 by a plug 
17. The plug 17 is inserted into the housing 1 at a forward connection end 
and held therein by an elastomeric O-ring. The acquisition structure 2 can 
comprise appropriate electrical circuitry or selected mechanical 
components suitable for detecting movement of the tip 9 and for generating 
appropriate signals in response thereto. The anterior end area of the 
housing 1 that receives the plug 17 is referred to as the connecting area 
18 for the exploratory tip 9. 
The illustrated acquisition structure 2 can comprise, according to one 
practice, a tube 12 in which an inner tube 14 is provided. Suitable signal 
transmitting components extend from the sensor pin 10 into the inner tube 
14. Sensors (not shown) can be provided between the tube 12 and the inner 
tube 14, so as to detect movement of the transmission means, either 
magnetically or by induction for example. The sensors determine the 
position of the sensor pin 10 as measured values in this fashion. 
Thus for example the depth of pockets in the gums of a patient can be 
determined. The measured values can be fed through a transmission cable to 
a computer and evaluated and/or stored therein. The transmission cable can 
be connected to a plug provided at a rear end 15 of the housing 1. 
The illustrated housing 1 can be free of externally projecting actuating 
elements, FIG. 1, and can have a maximum outside diameter of about 1 cm 
adjacent the connecting area 18 over a length of at least about 5 cm. 
The acquisition structure 2 in the device shown in FIGS. 2 and 3 comprise a 
printed circuit board (PCB) 3 and a probe 4 located on the PCB 3 and 
designed using SMD technology, with a push-button 4 outside housing 1 
being actuated by means of a button cap 5. In FIG. 2, only one such probe 
is provided. purely as an example. Probe 4 can serve to store the measured 
value detected at the moment by the exploratory tip 9. Additional 
functions and probes can be provided. Button cap 5 can be composed of 
TEFLON and can have a circumferential projection 6 at its lower end. The 
projection 6 can be shaped approximately as a barb, with a diagonal 
surface and a straight section. 
Button cap 5 can be introduced into the matching opening in the housing 1 
with the aid of the sloping surface of the projection, while the straight 
portion of the projection 6 holds the button cap 5 permanently inside the 
housing 1. Forceps can be used to remove button cap 5 from housing 1, 
destroying or damaging the projection 6 in the process, so that the 
interior of the housing 1 can be cleaned especially thoroughly at regular 
intervals. 
Pressure is transmitted from button cap 5 to the probe 4 by an elastomer 
plunger 7 that tapers conically at its lower end and acts on the probe 4. 
The plunger 7 does not fill the cavity inside button cap 5 completely, so 
that button cap 5 tends to deform as it is inserted into housing 1. 
With further reference to FIG. 3, the free space or cavity 11, within which 
the button cap 5 and projection 6 are located inside housing 1, is limited 
to a very small area around probe 4. Moreover, the acquisition structure 2 
are potted inside the housing 1 by a potting compound 8 that avoids air 
inclusions trapped inside the housing 1 (e.g., eliminates air pockets 
between the cylinder 12 and the outer housing) while concomitantly holding 
the structure 2 inside the housing 1 so as to be generally resistant to 
vibration. In order to prevent penetration of the potting compound 8 into 
the space between tube 12 and inner tube 14, these tubes can be sealed at 
their anterior ends by a ring that seals off the above-mentioned 
intermediate space but has a central opening that allows the transmission 
means to extend into the inner tube 14. 
The potting compound 8 can consist for example of a two-component silicone 
material that is thin when added to the housing 1 after the acquisition 
components 2 have been placed inside housing 1. By using removable 
fillers, the free space provided around probe 4 into which potting 
compound 8 does not penetrate, as shown in FIG. 3, can be kept clear as 
the compound sets. These fillers can be removed after the potting compound 
has set. Alternatively, this space can be kept clear with the aid of any 
suitable blocking tools, such as a cotton swab for example, with the 
potting compound 8 being kept at a distance from the probe 4 as it sets. 
By omitting probe 4, the housing can be kept thinner as in FIG. 2 and can 
facilitate examinations in the mouth of a patient. Another source of 
relief for the patient is that two bends 16 spaced apart from one another 
are provided on the exploratory probe 9. In a preferred embodiment the 
bends extend in opposite directions. Thus sensor pin 10 can be guided 
relatively steeply behind the patient's teeth without the entire device 
having to be held at the same steep angle. The result is a smaller 
required aperture angle of the patient's mouth, so that first the 
treatment is more pleasant for the patient and second the risk of 
measurement errors caused by improper positioning of the sensor pin is 
reduced. 
The functions to be triggered by the probe can also be provided in 
probe-less devices in which a foot switch is provided for example, with 
the transmission cable then being connected to the plug on a rear end 15 
of the housing 1 and running first to the foot switch and from there to 
the computer. 
It will thus be seen that the invention efficiently attains the objects set 
forth above, among those made apparent from the preceding description. 
Since certain changes may be made in the above constructions without 
departing from the scope of the invention, it is intended that all matter 
contained in the above description or shown in the accompanying drawings 
be interpreted as illustrative and not in a limiting sense. 
It is also to be understood that the following claims are to cover all 
generic and specific features of the invention described herein, and all 
statements of the scope of the invention which, as a matter of language, 
might be said to fall therebetween.