US 3140709 A
Description (OCR text may contain errors)
A. Z. WEISZ July 14, 1964 APPARATUS AND PROCESS FOR RELIEVING PAIN AND DISCOMFORT Filed May 29, 1961 2 Sheets-Sheet 1 F195 Ema:
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0 2'3 ALEXA/V05? z Wf/JZ D 2? BY United States Patent 3 140,709 APPARATUS AND RROCESS FOR RELIEVING PAIN AND DISCOMFORT Alexander Z. Weisz, Belmont, Mass, assignor to Bolt Beranelr and Newman Inc., Cambridge, Mass., :1 corporation of Massachusetts Filed May 29, 1961, Ser. No. 113,476 11 Claims. (Cl. 128--1) The present invention relates to apparatus and processes for relieving a patients pain and discomfort with the aid of acoustic energy.
In copending Application Serial No. 779,365 of Wallace 1. Gardner and Joseph C. R. Licklider, filed December 10, 1958, now Patent No. 2,986,140 for apparatus and process for relieving pain and discomfort, there are disclosed techniques and apparatus for alleviating a patients sensation of pain and discomfort by flooding the auditory system of the patient with appropriate acoustic energy. This invention has gone into wide use and has proved to be highly successful. In order to protect the hearing of the patient, it has become standard procedure in the utilization of the audio analgesic treatments employing the above-mentioned techniques and apparatus, to limit the length of uninterrupted exposure of the patient to the audio energy to substantially minutes at the highest intensity settings of the apparatus. While it is possible to increase the allowable exposure time by reducing the acoustic energy intensities offered to the patients auditory system, the intensity of the pain and discomfort that may be alleviated becomes thereby decreased.
An object of the present invention, accordingly, is to provide a new and improved process and apparatus for relieving a patients sensation of pain and discomfort through the employment of appropriate acoustic energy that shall extend the permissible exposure time of the patient to acoustic energy of intensities sufiicient to alleviate severe pain, without exceeding the above-mentioned established maximum allowable exposure.
A further object is to provide a new and improved audio energy analgesic apparatus.
Other and further objects will be explained hereinafter and will be more particularly pointed out in connection with the appended claims.
In summary, the invention relates to the obviating of a patients reaction to pain and discomfort by alternating the application of the appropriate acoustic energy between opposite sides of the patients auditory system.
The invention will now be described in connection with the accompanying drawings, FIG. 1 of which is a combined block and schematic circuit diagram illustrating the invention in preferred form; and
FIG. 2 is a similar view of a modification.
Referring to FIG. 1, audible sound signals, preferably substantially continuous in frequency spectrum and time, are generated by the sources 1 and 1 which may respectively be sources of intelligible sound signals such as music and the like and of noise signals and the like. As is explained in the said copending application, such sound signals are applied to the auditory system of the patient during the subjection of the patient to a painor discomfort-producing stimulus, with amplitude level controls provided as at 2 and 2' for enabling the patient relatively to increase the amplitude level of the noise and music signals at least to a level substantially 100 decibels above .0002 ubal for a period at least substantially commensurate with the duration of the stimulus, whereby said sensation of pain or discomfort resulting from said stimulus is relieved. In the system of FIG. 1, the music is shown applied, preferably stereophonically, through left and right amplifier channels 4 and 6, respectively, and through resistors R1 and R2 and conductors 3 and 5 to 3,140,709 Patented July 14, 1964 the left and right sound-reproducing earphones 4' and 6', which are peripherally provided with flanges, shown in heavy lines at F, that mask other sounds from being injected through the ears into the auditory system.
The output of the noise source 1', which may, for example, be a thermal gas tube, as is well known, is shown fed through a pair of photo-resistors R and R and respective resistances R3 and R4 to the respective conductors 3 and 5 that feed the sound-reproducing earphones or other sound-injecting devices 4 and 6. The photo resistors are also connected to appropriate ground cir cuits through respective resistances R5 and R6. A motordriven cam 7 is shown operating upon a pivoted switch S to cause the switch to alternately connect with upper and lower contact members 9 and 11. They, in turn, connect with the filaments F and F of respective light sources L and L disposed to illuminate, respectively, the photo-resistors R and R. The switch S is electrically connected through a variable resistor R9 to the ground or other terminal and, depending upon whether the switch S contacts the contactor 9 or 11 through the respective resistors R7 and R8, to a source S of voltage, such as the alternating current mains. As the motor-driven cam 7 rotates, the lamps L and L will become alternately illuminated, alternately raising and lowering the resistance of the photo-resistors R and R and thus causing the noise signal alternately to be fed to the left and right earphones or similar devices 4 and 6', during the continual background feeding of the music thereto.
This alternate or intermittent application of the noise sound (which is generally most effective in reducing the sensation of pain and discomfort) to opposite sides of the patients auditory system, enables the taking advantage of a significant reduction in the growth of temporary threshold shift in each ear, for example, during such alternate or intermittent exposure. In fact, at the same intensities or amplitude levels which conventionally allow a 15 minute exposure, the present invention enables the patient safely to tolerate a total of 135 minutes exposure to the audio energy by the alternation of the same between opposite sides of the auditory system of the patient. Since sound pressure levels of about db or less do not contribute to temporary threshold shifts, it is not necessary to shut the sound off completely from the side of the auditory system to which the noise source is not being fed. The music, therefore, may remain on continuously while the masking noise sound is alternated between op posite sides of the auditory system. It has been found that the patient is able to follow the music with intelligibility under such conditions despite the high masking noise levels to which the patient adjusts the output of the source 1' to obtain relief from the pain.
Other advantages accruing to the present invention reside in the fact that the sound has a spatial and temporal dimension that adds to the desirable effects of distraction and diversion, with certain natural rhythms, such as those of waves washing ashore or breathing, simulated by the alternating mechanism with further beneficial effects. In addition, since the analgesic eifect is to some extent proportional to the sound pressure level applied to the ear, the present invention permits, for equivalent temporary threshold shifts, the attenuation of higher intensities of pain; though, of course, the time of exposure to the audio energy must be sacrificed for such higher levels. A convenient alternating rhythm or frequency successfully employed has been once every four seconds, with some over lap or decay during the change-over, which has been found to be pleasing to the patient.
In the modification of FIG. 2, the output of the noise source 1 is alternated by a motor-driven rheostat, shown in circular form at RH provided with diametrically opposed conductive sliders S1 and S2 respectively insulated from and electrically connected to the shaft 13 of the motor M, but both rotated therewith.- Brushes 15 and 17 respectively engaging a conductive cylinder 19 connected to the slider S1 and the shaft 13, will thus alternately feed'incr'easing and decreasing levels of noise to amplifiers'No. 1 and No.'2, alternately to energize the sound reproducing members 4 and 6.
Further modifications will occur to those skilled in the art, and all such are considered to fall within the spirit and scope of the invention as defined in the appended claims.
What is claimed is:
1. A' process for obviating a patients reaction of pain and discomfortto a painor discomfort-producing stimulus, that comprises, producing acoustic energy including noise-like sound signals of amplitude level adjustable at least to substantially 100 decibels above 0.0002 microbar, applying the energy to the auditory system of the patient during the application of said stimulus, adjusting the level of the acoustic energy to a value at which the patients said reaction is substantially obviated, and alternating the application of the energy between opposite sides of the said auditory system.
2. A process for obviating a patients reaction of pain and discomfort to a pain-or-discomfort-producing stimulus, that comprises, producing acoustic energy comprising noise of amplitude level adjustable at least to substantially 100 decibels above 0.0002 microbar, applying the energy to the auditory system of the patient during the application of the said stimulus, adjusting the level of the acoustic energy to a value at which the patients said reaction is substantially obviated, and alternating the application of the energy between opposite sides of the said auditory system.
3. A process for obviating a patients reaction of pain and discomfort to a painor discomfort-producing stimulus, that comprises, producing acoustic energy comprising an intelligible signal such as music and the like and a noise-like signal of amplitude level adjustable at least to substantially 100 decibels above 0.0002 microbar, applying the energy to the auditory system of the patient during the application of the said stimulus, adjusting the level of the noise-likesignal relative to the intelligible signal to a value at which the patients said reaction is substantially obviated, and alternating the application of the noise-like'signal between opposite sides of the said auditory system.
4. A process as claimed in claim 1 and in which the alternating is effected by gradually reducing the level of the "energy applied to one side of the said auditory system while gradually increasing the level of the energy applied to the other side.
5. A process as claimed in claim 1 and in which the alternating is effected at a predetermined rhythm.
6. A process as claimed in claim 5 and in which the rhythm is of the order of once every few seconds.
7. Apparatus of the character described comprising a source of electrical signals corresponding to noise-like sound energy of amplitude level adjustable at least to substantially decibels above 0.0002 microbar, a pair of sound-reproducing means connected to the source to reproduce noise sound energy from the said signals, and means interposed in the connection between the source and the sound-reproducing means for cyclically substantially simultaneously varying in respectively opposite directions, the level of the electrical signals fed to each of the respective sound-reproducing means of the said pair of sound-reproducing means in order to increase the sound volume in one sound-reproducing means while decreasing the volume in the other. I
8. Apparatus of the character described comprising source means of electrical signals corresponding to intelligible sound energy, such as music and the like, and noise-like sound energy of amplitude level adjustable at least to substantially 100 decibels above 0.0002 microbar, a pair of sound-reproducing means connected to the source means to reproduce sound energy from the said signals, and means interposed in a connection between the source means and the sound-reproducing means for cyclically substantially simultaneously varying, in respectively opposite directions, the level of the electrical signals corresponding to noise-like sound energy fed to each of the respective sound reproducing means of the said pair of sound-reproducing means in order to increase the sound volume in the sound-reproducing means while decreasing the volume in the other, while continually applying the electrical signals corresponding to the intelligible sound energy to the sound-reproducing means.
9. Apparatus as claimed in claim 8 and in which the said source means comprises a source of electrical signals corresponding. to music and the like permanently connected to the sound-reproducing means and a separate source of electrical signals corresponding to noise-like sound energy connected through the said interposed alternately-varying-level means.
10. Apparatus as claimed in claim 7 and in which the alternate]y-varying-level means comprises photo-sensitive variable impedance means.
11. Apparatus as claimed in claim 7 and in which the alternately-varying-level means comprises rheostat means provided with simultaneous increasing and decreasing resistance controls.
References Cited in the file of this patent UNITED STATES PATENTS 2,114,019 Friebus Apr. 12, 1938 2,373,560 Hanert Apr. 10, 1945 2,986,140 Gardner et al May 30, 1961