US3515466A - Hand perimeter - Google Patents

Description

c,v APPLE HAND PERIMETER June 2, 1970 2 sheets-Sheet 1 Filed July l5, 1969 hkUlll M, um

June 2, 1970 c. APPLE: 3,515,466

' mmv PERIMETER Filed July 15, 1969 z sheets-sheet 2 United States Patent O 3,515,466 HAND PERMETER Carl Apple, 5801 N. Sheridan Road, Chicago, lll. 60626 Continuation-impart of application Ser. No. 478,919, Aug. 11, 1965. This application July 15, 1969, Ser.

Inf. cl. A61b 3/02 U.S. Cl. 351-23 1 Claim ABSTRACT OF THE DISCLOSURE A hand perimeter in which light beams from light bulbs provide the central stationary or frontal and the movable peripheral targets. The movable peripheral light has movable aperture masks and color lters which are housed with the light within an arcuate arm which provides a light shield. The arm, which is restricted to a quadrant, is pivoted at the upper end of a battery case which forms the handle and to which a face stop is also connected by a curved support which clears the arcuate arm when the arm is rotated into the plane of the battery case.

CROSS REFERENCES TO RELATED PATENTS AND APPLICATIONS This application is a continuation in part of my prior application Ser. No. 478,919, led Aug. 11, 1965, and now abandoned.

SUMMARY OE THE INVENTION The usual arrangement of a perimeter is such that the patient looks straight ahead at a front target which fixes his line of vision, and then an additional target is moved or slid from the side around toward the front target until the second target comes within the peripheral vision of the patient. When this happens the patient announces the fact and the physician notes the angularity existing between the two targets. Normally, such readings are taken several times on both sides and with both eyes, and also are taken in several angular planes intermediate the horizontal and the vertical. Usually also the instrument provides for a change in the size of the peripheral target, and there is often some arrangement for determining the peripheral vision in several different colors, usually white,

. red, blue, and green.

The utility of a perimeter is well known to physicians. By its use the physician can make at least a diagnosis as to an area of the patients retina which is aifected. Common conditions which thus may be initially diagnosed include glaucoma, optic nerve diseases, and brain lesions such, for example, as may be suffered by stroke patients.

A simple instrument used for this purpose is known yas a hand perimeter. The Schweigger hand perimeter consists of a handle to be held by the patient or physician and a stop which rests against the chin below the lower lip or the cheekbone beneath the eye being tested so as to x the instrument in a relatively standard position. The perimeter has an arc pivotally mounted to the handle which is calibrated and along which the peripheral targets can be moved. The front target consists of a small mirror or other reective device positioned directly above the handle, which serves as a reference point. The arc extends off to both sides of the central target and along which the movable targets may be moved from either extreme end position into the peripheral vision of the patient. A number of movable targets are provided so as to permit the physician a choice of target size and color. The Schweigger perimeter must be used in an illuminated room and the patient preferably is sitting, so that .a light beam 3,515,466 Patented June 2, 1970 may be cast from behind the patients head onto the front target to reflect on the pupil of the eye being tested.

Illuminated and electric bulb targetV perimeters such as the Ferree-Rand and the DeZeng perimeters have also been devised and are in common use. These are stationary perimeters and the patient must be tested in a sitting position with his head held on or against a chin rest. These perimeters obviously must be used at or adjacent to a source of electricity and are commonly used in the physicians ofce or in a hospital.

The above prior art instruments have several important limitations Iwhich the hand perimeter of the present invention overcomes.

The patient in being tested by these instruments must be in a sitting position. This is required in using the Ferree- Rand and DeZeng instruments, and in using the Schweigger hand perimeter if the front target is illuminated from a light source behind the patients head. The hand perimeter of this invention being completely self contained and illuminated, can be used in testing the bedridden and those too infirm to sit.

The popular Schweigger hand perimeter must be used in a lighted room or area. The patient otherwise cannot perceive the peripheral or movable targets. These targets have the further disadvantage of becoming dirty and the colors not readily identifiable. This latter disadvantage is also true of the standard perimeters which do not use illuminated or light source targets. The hand perimeter of this invention may be used in the dark, and both targets `being of a light bulb source, will retain their brilliance for long periods. The only service requirement would be the replacement of dead batteries.

Being illuminated and self contained, the hand perimeter of this invention can be used at the scene of an emergency, such as an automobile accident, a riot, or a battlefield. No external light is needed as would be true with the Schweigger hand perimeter. 'Ihe victim or patient may be disabled to the point of not being able to stand or sit and the examination may be performed.

Since the illuminated hand perimeter of this invention is self contained it may be used in places Where there is no source of electricity, such as those described in the preceding paragraph, or where there has been a power failure. This is not possible with Ferree-Rand and DeZeng perimeters which depend upon the conventional electric power source.

The conventional and popular perimeters use a semicircular arm pivotally mounted at its center on the axis of the frontal target and along which the peripheral target is moved or slid. The hand perimeter of this invention incorporates the arcuate arm in the form of a quadrant pivoted at one end on the axis of the frontal target. The quarter arc or quadrant is for the convenience of the doctor who realizes immediately what part of the retina is involved from a reading of the movable target position and the angular position of the arm.

The principal object of the present invention is to provide a new and improved hand perimeter having frontal and peripheral targets of light bulbs and which is self contained and has a battery source of electricity for the light bulbs.

Another object is to provide a new and improved illuminated hand perimeter wherein the peripheral target is movable along a quadrant or quarter arc to enable the examining physician quickly to realize the area of the retina affected.

Another object is to provide a new and improved illuminated hand perimeter wherein a battery case serves as the handle, the frontal target light bulb is mounted on the head of the battery case, and the quadrant or arcuate arm comprises a pair of spaced channel members between which slides a block carrying peripheral target light bulb,

selective size apertures, and a selective color filter element.

Additional objects and advantages of this invention will become apparent from the following description of a preferred embodiment of my invention, which is illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagrammatic perspective view illustrating the hand perimeter of the present invention and its manner of use;

FIG. 2 is a side view of the hand perimeter embodying the present invention;

FIG. 3 is a view of the perimeter head taken from the back, and may be considered as taken in the direction of the arrows substantially along the line 3-3 of FIG. 2;

FIG. 4 is a horizontal sectional view which may be considered as taken in the direction of the arrows substantially along the line 4-4 of FIG. 2, illustrating the construction of the arc and the target members associated therewith;

FIG. 5 is an enlarged transverse sectional view through the movable peripheral target member shown in association with the arc, and may be considered as taken in the direction of the arrows substantially along the line 5 5 of FIG. 4;

FIG. 6 is a vertical sectional view taken in the direction of the arrows along the line 6--6 of FIG. 5, illustrating the mechanism for changing the size of the light source of the peripheral target; and

FIG. 7 is a sectional view taken in the direction of the arrows along the line 7-7 of FIG. 5, generally similar to FIG. 6, but showing the mechanism for changing the color of the peripheral target.

SPECIFIC DESCRIPTION The hand perimeter of the present invention includes a handle 10 which comprises a cylindrical tube, which serves as a battery case for the instrument, and it normally will contain a pair of ashlight batteries or the equivalent which are used for illuminating the electric lamps to be referred to in greater detail presently. At its bottom end the handle 10 has a base fitting 11 provided with a closure or cap 12 which may be screw threaded thereto or otherwise suitably attached, such that the lower end of the tube can be opened for exchanging batteries. The fitting 11 is also connected to one end of a stili, but bendable, piece of wire 14 which extends away from the tting in a substantially radial direction for a distance, and then is bent upwardly in an S curve and is provided at its free end with a rest 16 which is adapted to be held against the patients chin or the cheekbone beneath the eye being examined. For purposes of adjustment to individual patients, this wire may be bent slightly.

As is illustrated in FIG. 1, the handle 10X is intended to be held by the patient, or by the physician or his assistant, with the rest 16 located against his chin slightly below his lower lip for the purpose of orientng the apparatus and spacing it at a proper distance in front of the eye being tested.

At its upper end the battery case and handle 10 is provided with an electric switch, which is not shown specifically since it forms no part of the present invention and its construction is conventional. This switch in the specific embodiment is actuated by rotating a ring member 18 slightly about the axis of the handle 10 in one direction or the other to turn the target lights on and oir. When the switch is in the on position, the battery is connected to energize a pair of leads 20 and 22 which are connected, in turn, as will be explained, to a small light bulb at the center of the apparatus directly above the handle which comprises the front target and is intended to be looked at intently by the patient, and to a separate movable light bulb which indicates the patients peripheral vision when' it is slid around into such a position relative to the central or frontal light bulb that it can be seen -by the patient.

The handle 10 also carries an upstanding plate 24 to which a pivoted or arcuate arm 26 is attached by means of a bolt or headed pin 28. This pin 28 rotates with the arm 26 as it is moved from horizontal position and carries a pointer 30 which indicates upon a degree marked circle 32 on the back of the plate 24 the relative angularity of the arm 26 with respect to the horizontal in either direction.

In alignment with the pin 28, the arm 26, on its forward side, carries a socket and miniature light bulb 32 which can rbe observed by the patient who has the rest 16 against his chin. Thus, the light bulb 32 stays in alignment with the pin 28 as the arm 26 is pivoted relative to the handle 10, and it serves as the front target to cast its 4beam onto the pupil of the eye being examined.

The arcuate arm 26 is made up of two curved segments as is best illustrated in FIGS. 4 and 5, such that these segments curve outwardly in alignment with each other throughout an angularity of about or so relative to the position of the straight ahead front target light bulb 32. This arm 26 can be best considered as constituting a pair of channels 38 and 40 which are positioned with their open sides facing but spaced from each other to - deline slots 42 and 44 which extend from end to end. At their ends the two channels are secured together by screws 34 which are threaded into blocks 36 which are iitted to and ll the space between the channels (FIG. 4).

The curved channels 38, 40 and blocks 36 may be made of stainless steel or of a rigid synthetic resinous material, and together they form what amounts to a rectangular tube, except for the back slot 42 and inner or front slot 44.

The generally rectangular hollow arm 26 thus formed carries a slider46. This slider takes the form of a block, which may be made of stainless steel and tits snugly and #without bending within the arm 26. vIt has a rearward extension 48 grooved lalong its top and bottom sides at 51 so that these grooves tit the slot 42. The block 46 adds to the rigidity of the arm 26 and is free to slide therealong, but is not movable otherwise relative to the tube formed by the upper and lower channels 38 and 40. This block 46 is slid into position from the outer end of the arm 26 before the end spacing block 36 is secured in position.

The front of the block 46 is provided with a front or inwardly facing aperture 49 and a socket for a miniature light bulb 50 which is in alignment with the inner or front slot 44 so that the light from the bulb 50 shines forwardly through the slot toward the patient using the device, and constitutes the peripheral target. The previously mentioned exible electric cord 22 connects the socket for the perimeter target light bulb 50 with the terminal of the combination batterycase and handle 10.

The block 46 is provided with a quill shaft 52 which is journaled therethrough from front to back in a horizontaal position directly above the light bulb 50. The rearward end of this quill shaft 52 is equipped with a knob 54 by means of which the shaft can be rotated, and at its forward end the quill shaft carries a disc S6 divided crcumferentially into four light transmitting panels which carry colored transparent lter elements 58 (FIG. 7). Thus, 'by rotating the knob 54, any one of these four iilter elements can be brought into a position in front of the perimeter target light bulb 50 so that the light seen by the patient will have the chosen color. Normally, these filters 58 will be white, red, blue, and green.

It is also advisable to be able to control the diametral size of the light beam from the perimeter light bulb 50, and this is accomplished by providing a second disc 60 in front of the filter elements 58, the second disc being connected to a shaft 62 which extends through the quill shaft 52 and out the rearwaard end thereof where the end of the shaft 62 is secured to a second control knob 64. The disc 60 is provided in the embodiment shown with four apertures 66 which, in an instru-ment of convenient size, may have diameters of 3, 6, 8, and 10 mm., although other sizes may be substituted. The preferred size of these apertures will depend upon the overall size of the hand perimeter and, in general, they should be so sized that the light through the openings subtends respectively about l, 2, 3, and 4 degrees. As a convenience in determining when the apertures 66 or filters 58 are in place, the knobs 54 and 64 may carry appropriate indicia, such as the ribs indicated at 67, or something similar.

The instrument is used in the following manner. The patient (or the physician or his assistant) holds the handle 10 directly in front of his face with his chin (or cheek bone) against the rest 16, and the electric light bulbs 32 and 50 are turned on by rotating the switch control member 18. The movable target light is moved t the end of its arm essentially to a position against the outer end block 36, or at least far enough so that it is out of the field of 'vision of the patient when the patient is looking at the central or frontal target light 32.

The knobs 64 and 54 are turned so as to bring the proper size aperture 66 and the proper color on the filter disc 56 into alignment with the light bulb 50. With the patient looking forwardly at the target light 32, the block or carriage 46 which has the light bulb 50 therein is slid slowly around upon the track formed by the channels 38 and 40 until the patient sees the beam from the light 50. At this juncture the angular position in the track of the carriage or block 56 is noted, and for convenience, the back side of the arm 26 can be graduated, as indicated at 68 in FIG. 3, to indicate this reading directly. Usually two or three readings are taken, and it is desirable for some examinations that readings be taken with different sizes and colors of the movable target.

The arcuate arm 26 can be pivoted -around its central point 28 into any desired angular relationship so that a reading may be taken in any plane. As shown, the arm 26 extends to one side of the handle only, and therefore, to take a reading on the opposite side, it is necessary merely to rotate the arm 26 into a position on the other side. By use of this hand perimeter with the arm 26 in the form of a quadrant, the examining physician may immediately determine from angular position of the arm 26 what portion of the eye is involved, which is not as readily noted when the arcuate arm is semicircular.

Ordinarily, readings will be taken in a darkened room or at least in a room where the illumination level is low enough so that the brilliance of the light bulbs 32 and 50 overpowers the room illumination suiiiciently so that the patient is not aware of distinguishing any of the apparatus other than the light beams. Note also that since the slider, which comprises the block 46 and its fittings, is wholly within the arcuate arm 26, the patient cannot see any apparatus associated with the peripheral target in advance of the beam from the bulb 50. Nothing, therefore, tells him that he is about to see the moving light 50 prior to the time he actually sees it. This arrangement removes a common source of false readings which may tend to indicate that the patient has a wider angularity of peripheral vision than he actually has. This, incidentally, is a problem associated with all prior perimeters with 'which I am familiar. Note too that the controls for the color filter and the disc which determines the size of the light aperture are grouped at the back of the apparatus where they cannot be seen by the patient.

-An additional advantage of this apparatus is that since the light sources are much more brilliant and contrast more strongly with the background than do the ordinary targets, it is possible to use aperture sizes for the openings I66 which are smaller than the ordinary white or colored targets, and therefore a precise indication can be obtained much more quickly and with fewer trials for averaging purposes than is ordinarily true.

It will be appreciated from the foregoing description that the objectives and advantages over the prior art stated at the beginning of this description are fully obtained by the hand perimeter described and also shown in the accompanying drawings.

It will be observed from FIG. 2 that the instrument -may be folded into la single plane for ease in packing into a case and carrying.

Having described my invention, what I claim as new and useful and desire to secure by Letters Patent of the United States is:

1. A hand perimeter instrument comprising in combination a handle, a stop element carried by said handle and adapted to be held against a bony part of the patients face to orient and steady the instrument, said handle fo-rrning a battery oase for the instrument and carrying electric switch means, a frontal target comprising a rst lightbulb electrically connected to said switch means, carried at the upper end of said handle, and usable by the patient for determining when the patients eye is looking in a certain direction relative to the instrument, a curved quadrant arm extending away from said frontal target and curving forwardly so as to be at a substantially constant distance from the patients eye through an angularity of approximately relative to said frontal target, pivot means mounting said curved quadrant arm to the upper end of said handle for rotation about the axis of said frontal target, said curved quadrant arm being structurally substantially rigid, hollow and comprising a pair of facing channel members interconnected at their extremities and spaced from each other to define a linear light transmitting slot in the forward surface thereof and a rear slot opposite said rst and forward slot, a block fitting snugly but slidably within said hollow quadrant arm from substantially end to end thereof and adding to the rigidity of said arm, a second lightbulb electrically connected to said switch means forming a peripheral target carried by said block and positioned to emit a light beam through said forward slot, a rearward extension on said block projecting through said rear slot for manually sliding said block in said arm, said extension having grooves in its upper and lower portions to engage the edge of the channel legs defining said -rear slot, said block carrying a pair of rotatable discs within said quadrant arm and positioned between said second lightbulb and said forward slot, one of said discs carrying a group of colored filters, the other of said discs providing a series of diferent sized apertures through which the peripheral light beam is projected, and shaft members extending through said rearward extension of said block for selectively rotating said discs, Iand said stop element being connected to the lower end of said handle by a curved support which is shaped to permit rotation of said curved quadrant arm into substantially the plane of said handle for universal diagnostic use and for convenient storage of the instrument.

References Cited Max Poser, Optical Journal and Review of Optometry, The Perimeter, Jan. 1, 1945.

DAVID SCHONBERG, Primary Examiner P. A. SACHER, Assistant Examiner

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