US2466054A - Method and apparatus for minimizing pain caused by drilling teeth - Google Patents

Description

April 5, 1949.

v. H. SIEBEL 2,466,054. METHOD AND APPARATUS FOR MINIMIZING PAIN CAUSED BY DRILLING TEETH Filed Sept. 27, 1947 manna V r y INVENTOR.

5i ebel BY ATTORNEYS Patented Apr- 5, 1949 NT OFFICE nm'rnon arm mm'rus FOR ram CAUSED nrmmmmo 'ran'rn Victor B. Siebel, hiew YorL N. Y.

' Application September :1, 1941, Serial No. 176,449

My invention relates to a new and improved method and new and improved means for minimizing or eliminating the pain which is caused by drilling teeth.

From actual experience, I have observed that although deaf mutes suffer the same pain as normal persons when their teeth are extractedand in other types of dental work, such deaf mutes do not feel any pain when a tooth is being drilled.

As a result of extensive observation in the dental treatment of deaf mutes and from extensive experience in treatin normal patients, I have found that in patients who can hear, the pain which results from drilling teeth isv due wholly or largely to the transmission of the sound waves which are produced by the drill, to the organs of hearing. Such sound waves are transmitted to the organs of hearing through the bones of the head.

According to one embodiment of my invention, I locate a microphone or other sound-pick-up means'in the mouth of the patient. This mouth 8 Claims. (Cl. 128-1) which may be of equal amplitude or of any desired phase relation.

relative amplitude, and which havethe desired These two series of major or dominant sound waves move in opposite directions to the organs of hearing and they produce nodes or points of zero displacement at the sound organs. Whatever the theory may be, extensive testing with patients of normal hearing has shown that I can secure said results. The mouth microphone is preferably not too sensitive to mechanical vibranant sound waves which result from the drilling microphone is connected to the terminals of a source of unidirectional and constant current, such as a battery. This microphone circuit includes a variable resistor and a hand-operated switch and the primary coil of a transformer. The sound waves which are picked up by this month microphone, thus produce a variation in said battery current, in the usual manner. The secondary coil of said transformer is connected, preferably without amplification, to a receiver such as a telephone receiving unit. The diaphragm of the telephone receiver thus reproduces the unamplified sound waves which have been picked up by the mouth microphone. This telephone receiver is connected by two air tubes which provide two air columns of adjustable length. to two car pieces which are held on the ears of the patient. The ends of the secondary coil are connected to a potentiometer resistor, whereby any selected secondary voltage can be supplied'to the input of the telephone receiver, in order to regulate the current which is supplied to the telephone receiver and hence to regulate the intensity of the external sound waves which are reproduced by the diaphragm of the telephone re-' ceiver. The drill produces a dominant or major sound wave. By regulating said adjustable air columns,'I regulate the phase of the dominant or major sound wave which is transmitted through said air columns to the ears. I thus produce two respective series of internal and external major or dominant sound waves of the same frequency,

tion and diagrammatic drawing.

This drawing diagrammatically illustrates the circuit, when a course of direct current is used in the microphone circuit. 7

The mouth microphone M is made of suitable small size so that it can be kept in the mouth of the patient while the teeth are being drilled. This mouth microphone may be of any type, such as a pressure microphone, which type includes carbon and crystal microphones. This microphone is preferably of the button type which has carbon granules, so that the internal electrical resistance of the microphone is regulated by the sound waves which are produced in the month by the action of the drill. One of the terminals of the microphone M is connected to a conventional handoperated switch 2 pivoted at l2, and which can be turned to touch the contact 3 in order to close the circuit of battery 5. The other terminal of the microphone is connected to one end of a resistor 4. One terminal of the battery 5 is connected to an adjustable connector 60. which is slidable alon the resistor 4, so that any desired resistance can be introduced into the circuit of the mouth microphone M, in addition to the variable resistance of the mouth microphone M. The

other terminal of the battery 5 is connected through a primary coil 6 to the contact 3 of the blade 2. When the battery circuit is closed, the internal sound waves which are produced in the aseaou cuit in the well-known manner, so that a varying unidirectional current is sent through the primary coil '6. The primary coil 6 isinductively coupled to a secondary coil 1, whose respective ends are connected to the ends 13 and H of a potentiometer'resistor a which may be of suitable high resistance, such as 25,000 ohms to'1,000,000 One terminal of a conventional telephone receiver T is connected to. the end ll of the resistor 8. The other terminal of the receiver T is connected to a slidable contact l so that any selected part of the potentiometer resistor 8 is included in the circuit of the telephone receiver T.

When the amperage oi the direct current in the 7 ,primary coil 6 is varied by varying the intemal' resistance of mouth microphone I4 by the sound waves, a corresponding alternating signal current is induced in secondary coil 6, thus producing a corresponding alternating voltage between the" ends i3 and I .of the potentiometer resistor 8. By adjusting the slide l0 between the ends I! and it of the potentiometer resistor 8, I can pick ofl any selected part of said alternating voltage, to be applied to the local circuit of the telephone receiver T. This telephone receiver T may be of the stand-, ard type which has a diaphragm of magnetic al-j loy and which has the coil of an electromagnet. The ends of said coil are the terminals towhich the slide i0 and point ll are respectively connected. I The variable current which is sent through said coil of receiver T operates the diaphragm of receiver T to externally reproduce the internal sound waves which are produced in the mouth by the drill,-and which are picked up by the mouth microphone M. The external sound waves which are thus reproduced by the diaphragm of receiver T are transmitted through an outlet of the casing of the receiverT to a tube I! to respective tubes l6 and lid, which are tele-. scopic relative totubes i5 and lid, which are respectively connected to the ear pieces 9. Since such telephone receiver is well-known, its details are not illustrated. I n The variable resistor 6a regulates the amplitude of the variations of the battery current which is supplied to primary coil 6. The potentiometer 8 makes it possible to regulate the amplitude oi the current variations which are supplied to the input circuit of the telephone receiver unit T, and hence to regulate the external amplitude of the sound waves which are produced by the diaphragm of the receiver unit T. The tubes I 5-46 and ISa-lia interflt closely, so as to provide two respective air columns, whose respective lengths can be adjusted. Any convenetional means are provided in order to hold the tubes l5l6 and ISa-lGa in selected i'espec tive adjusted positions. Said tubes are prefers ably adjusted so as to provide respective air columns of equal length. In a practical device which I have extensively tested, a range of adjustment of six inches of said air columns has been found suflicient,

The velocity of sound through the bones of the head is much greater than through air. By regulating the lengths of said two air columns, I can produce external sound waves through said air columns to the organs of hearing, which annul theinternal sound waves which are transmitted It is well-known to use a microphone which picks up sound waves, 'to modulate a high-irequency alternating current, so that said altemating current has audio-frequency modulations which correspond to said picked-up sound waves,

and to-couple said modulated alternating current with a telephone receiver. ,Hence the invention is not limited to a system. which employs a battery current. It is alsd'fweg known to'transmit sound waves by bone conductionto'the organs or hearing, in hearing aids for deaf persons, so that the invention is not limited to the specific method illustrated herein, in which the reprolocated in the mouth of the patient is the microphone M and parts 01 the leads or wires which connect the terminals of the microphone to its circuit.

I have disclosed a preferred embodiment of my, invention, but numerous changes and omissions and additions and substitutions can be made without departing from its scope.

The variation in the lengths of the air columns may produce a resonance eiiect, thus selecting one or more or the external sound waves, and suppressing one'or more of the external sound waves;

In practical devices which I have used, the

tubes I, II, "a, lid, II are made of soft and bendable vulcanized rubber, or hard rubber which has someflexibility. I can use other materials,

such asvarious plastics.

In the practical devices which I have used, the length of tube I1 is very small, as one inch. I can also use a Y-connection, of th'e'type used in a physicians stethoscope, in which tubes l6 and lia are connected directly to the outlet of the casing of the receiver T, thus eliminating tube l|- and the T-connection shown in the drawing. In the case of a Y-connection, there is a very short connector tube, like tube l1, and the outlet of the receiver T has a coupling nipple, which is located in the interior of said connector tube by screw-threads, cementing, by a friction In api actical device which I have used, the maximum length of the air columns from the receiver-T to the ear-pieces 9 is 15 inches, and the minimum length of said air-columns is 9 inches. These specific figures are illustrative, and the invention is not limited thereto.

Ineffect, the improved device operates like a physician's stethoscope. The position of slide i0 between the ends 13 and ll of the potentiometer, the lengths of the air columns and other factors, may be adjusted for each patient.

The invention is not limited to a method or system-in which the internal sound waves and external sound waves are of equal intensity, although the regulating means can be used tomake said respective internal and external sound waves of equal or substantially equal intensity.

In one aspect of my invention, I use a stethoscope device whose inlet is in themouth of the patient, and whose outlets are at the ear openings, together with optional and preferred means for regulating the intensity and phase and wave form of the external sound waves which are thus delivered to said ear openings, or for regulating said factors individually and in any desired combination. In the broadest aspect of my invention, I generally claim such stethoscope means.

As above noted, I can, by means of resonance or by selecting a microphone or a telephone receiver, which is mainly responsive to a selected sound frequency, regulate the wave form of the sound waves which are delivered to the ear open ings, so as to select and deliver the principal wave component which produces the maximum sensation of pain.

When the apparatus is properly regulated, the patient does not hear the noise of the drill, or said noise is at least minimized.

I claim:

1. A method of lessening the pain which is produced by drilling a tooth of a patient who can hear, which consists in picking up the internal sound waves which are produced in 'the mouth of the patient by the drill, said internal sound waves being thus picked up in the mouth of the patient, reproducing said internal sound waves externally of the mouth to provide external sound waves, and transmitting said external sound waves to the organs of hearing of the patient in a path which excludes the mouth.

2. A method according to claim 1 in which the amplitude of said external sound waves is regulated.

3. A method according to claim 1 in which the phase and amplitude of the dominant external sound waves is regulated to substantially annul the sound of the drill.

4. Apparatus for use in lessening the pain which is produced by drilling a tooth of a patient who can hear, comprising a mouth microphone which is sumciently small so that it can be inserted into the mouth of a patient, the terminals of said mouth microphone being connected to a microphone circuit which includes a source of current, a telephone input circuit, means for coupling said microphone circuit to said telephone input circuit, said telephone input circuit being associated with and operating a telephone unit, said telephone unit having an outlet which is coupled through two air columns of adjustable length to ear pieces.

5. A system for lessening the pain which is produced by drilling the tooth of a patient who can hear, comprising a sound-wave pick-up located in the mouth of the patient to pick up the internal sound waves which are produced in the mouth by the drilling action and which are transmitted internally to the organs of hearing of the patient, and means operative to deliver corresponding sound waves to the organs of hearing in a path which excludes the mouth.

6. A system according to claim 5 in which said means include amplitude-regulating means for regulating the amplitude of said corresponding sound waves.

7. A system according to claim 5 in which said means have phase-regulating means to regulate the phase between said corresponding sound waves and said internal waves.

8. A system according to claim 5 in which said means include amplitude-regulating means to regulate the amplitude of said corresponding sound waves and said transmitted sound waves, and also include phase-regulation means to regulate the phase relation between said internal waves and said corresponding waves.

VICTOR H. SIEBEL.

No references cited.

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