Abstract:
The present invention modifies the Goldmann-Weeker&#39;s dark adaptometer so that all testing may be done automatically and analysis of the data may be completed in a rapid manner and further varied. The automated dark adaptometer is composed of the standard Goldmann-Weeker&#39;s dark adactometer having the traditional Ganzfeld bowl attached thereon. A computer acting through a computer interface is connected to a stepper motor and shaft encoder. The stepper motor is connected to the light control knob of the dark adaptometer. The patient being tested inputs responses to a patient signaling switch which is connected to the computer interface. The computer has a program has a specialized program therein for controlling the change in light intensity, recording this change, recording the patients response thereto and any other desired variables.

Description:
STATEMENT OF GOVERNMENT INTEREST 
     The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon. 
    
    
     BACKGROUND 0F THE INVENTION 
     The present inventor relates to medical devices used in testing of human beings, and, in particular, relates to testing of eyes. 
     The Goldmann-Weeker&#39;s dark adaptometer is a medical testing instrument designed to measure the functions of the retinal photoreceptors. It has been in existence since about 1950 and since that time, the instrument has not been changed or the testing methods used therewith. 
     The current method of testing dark adaptation, using the Goldmann-Weeker&#39;s device, is as follows: A patient is seated in a darkened room with his chin resting on the rim of a Ganzfeld bowl mounted to the front of the instrument. The untested eye is patched over and a bright light is turned on for five minutes to bleach the retinal photoreceptors of the unpatched eye. The light is then turned off and the patient is asked to look at a dim red light near the center of the reflective bowl. The technician, seated at the opposite end of the instrument, then turns a control knob which increases the intensity of the light projected onto a small screen at the center of the bowl. When the patient can first detect the light, he knocks on the table and the technician pulls back on the control knob, perforating a piece of graph paper attached to a rotating drum at the top of the instrument. The technician then decreases the light intensity by rotating the control knob counterclockwise, waits 5 to 15 seconds, then once again increases the light intensity. This cycle is continued for 45 minutes and then is repeated in the other eye. Once the test is completed, the graph paper is removed from the drum and each of the perforations is accentuated with ink, yielding a dark adaptation curve. 
     This manual method requires the technician to remain in the room with the patient throughout the entire examination, administering a tedious, labor-intensive test and then meticulously prepare a graph before the data can be interpreted. Because the technician directly controls the rate and interval over which the light intensity is changed, a large amount of interoperator variability exists. Furthermore, because the data is recorded in &#34;hard-copy&#34; form, any additional manipulation is prohibitively time-consuming. 
     Thus, there exists a need for a improved dark adaptometer. 
     SUMMARY OF THE INVENTION 
     The present invention modifies the Goldmann-Weeker&#39;s dark adaptometer so that all testing may be done automatically and analysis of the data may be completed in a rapid manner and further varied. 
     The automated dark adaptometer of the present invention is composed of the standard Goldmann-Weeker&#39;s dark adaptometer having the traditional Ganzfeld bowl attached thereon. A computer acting through a computer interface is connected to a stepper motor and shaft encoder. The stepper motor is connected to the light control knob of the dark adaptometer. The patient being tested inputs responses to a patient signaling switch which is connected to the computer interface. The computer has a program has a specialized program therein for controlling the change in light intensity, recording this change, recording the patients response thereto and any other desired variables. 
     Therefore, one object of the present invention is to provide an improved Goldmann-Weeker&#39;s dark adaptometer. 
     Another object of the present invention is to provide a Goldmann-Weeker&#39;s dark adaptometer that is able to adjust the light intensity according to a specialized program. 
     Another object of the present invention is to provide a Goldmann-Weeker&#39;s dark adaptometer that is able to record all testing information as the patient reacts to the testing program. 
     Another object of the present invention is to provide a Goldmann-Weeker&#39;s dark adaptometer that is able to digitally analysis the testing information produced. 
     Another object of the present invention is to provide a Goldmann-Weeker&#39;s dark adaptometer that requires no human intervention during the testing process. 
     Another object of the present invention is to provide a Goldmann-Weeker&#39;s dark adaptometer that allows for the testing protocols to be customized easily. 
     Another object of the present invention is to provide a Goldmann-Weeker&#39;s dark adaptometer that wherein the data is digitally stored and can be further manipulated using graphing programs. 
     These and many other objects and advantages of the present invention will be ready apparent to one skilled in the pertinent art from the following detailed description of a preferred embodiment of the invention and the related drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 illustrates the automated dark adaptometer by block diagram. 
     FIG. 2 illustrates by electrical schematic the computer interface used in the present invention. 
     FIG. 3 is an illustration comparing the manual data to the automated data taken by the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention automates the Goldmann-Weeker&#39;s dark adaptometer. A specially programmed computer having an interface module drives a stepper motor connected to the dark adaptometer. 
     Referring to FIG. 1, the improved dark adaptometer 10 is shown in block schematic. A computer 12 such as a personal computer (PC) has a specialized program as shown in Table 1 for controlling the improved dark adaptometer 10. The computer 12 is connected to a computer interface 14 that controls of all the functions of a dark adaptometer 16 such as instrument on/off, high-intensity light on/off, variable light intensity control, records elapsed time and patient responses. Further the interface 14 accepts patient responses through a signaling switch 18. The interface 14 also connects to the stepper motor 20 and an absolute shaft encoder 22. The output shaft 24 of the stepper motor 20 connects to the light intensity control 26. 
     The method of testing a patient consists of turning on computer 12, loading the computer program noted in Table 1, and entering the patient information. The patient is seated in front of the improved dark adaptometer 10 in a darkened room with his chin on the adjustable chin rest 28 and one eye patched over. The computer begins the examination by resetting its internal clock to zero and illuminating the Ganzfeld bowl 30 with a bright light for five minutes to bleach the retinal photoreceptors of the tested eye. When the five minutes has elapsed, the computer 12 turns the light off. The computer again resets its clock than slowly increases the intensity of the light projected onto a screen at the center of the bowl by initiating forward movement of a stepper motor 20 attached to the control knob 26 of the dark adaptometer 16. When the patient can first detect the light, he presses a trigger switch 18 connected to the computer interface 14. The computer 12 records the elapsed time and the intensity of the light perceived. The light intensity is calculated by measuring the distance of the stepper motor travel from the start of the test from an absolute shaft encoder 22 attached to the stepper motor 20. The intensity is read from a calibration curve previously prepared using a standardized photometer. The computer 12 then decreases the light intensity by reversing the stepper motor 20, waits a random length of time, and then once again increases the light intensity. This cycle is repeated for 45 minutes, in accordance with standard testing methods. Once the test is complete, the data are stored to a disk in a format usable by almost any graphing program, not shown. The electrical schematic for the computer interface 14 is shown in FIG. 2. 
     The data obtained by the improved dark adaptometer 10 is shown in FIG. 3 as compared to the manual method. 
     
                       TABLE 1______________________________________EM Automated Dark Adaptometry______________________________________TYPE: infodisklname AS STRING * 15fname AS STRING * 15ssn AS STRING * 14test AS STRING * 3END TYPE;DIM darkinfo As indodiskDIM a(500, 2)DIM as(500, 2)c = 4935:     REM    c = stepper (intensity) countert = 17:       REM    t = motor speed (higher # = slower                rate)h = 175:      REM    h = trigger code (home = 175,                notebook = 168)b = 143:      REM    b = base code for interface &#34;ready&#34;u = 680:      REM    u = steps equalling one log intensity                unitsi = 250:     REM    si = decrease amount to start intensitypct = .85:    REM    pct = percent of intensity after signalst$ = &#34;00:00:00&#34;:         REM    st$ = start time for each test unitlight$ = &#34;00:05:00&#34;:         REM    light$ = bleaching timewarn$ = &#34;00:04:55&#34;:         REM    warn$ = time &#34;warning to start&#34;                will be given10   OUT 890, 2:           REM    Turns motor driver offOUT 888, 128:           REM    Opens stepper relayi = INP(889)IF i &lt;&gt; b THEN 6000030   CLSLOCATE 7, 29: PRINT &#34;Enter patient data:&#34;LOCATE 9, 29: LINE INPUT &#34;Last name: &#34;; l$LOCATE 10, 29: LINE INPUT &#34;First name: &#34;; F$LOCATE 11, 29: LINE INPUT &#34;Identifier (SSN): &#34;; s$LOCATE 14, 26: PRINT &#34;Is the information correct|?50   i$ = UCASE$(INKEY$)IF i$ = &#34;Y&#34; THEN 60IF i$ = &#34;N&#34; THEN 30GOTO 5060   CLSLOCATE 8, 28: PRINT &#34;Select testing protocol:&#34;LOCATE 10, 34: PRINT &#34;1) Yates&#39;&#34;LOCATE 11, 34: PRINT &#34;2) Standard&#34;LOCATE 12, 34: PRINT &#34;3) Custom&#34;70   i$ = INKEY$pt = VAL(i$)IF i$ = &#34;1&#34; OR i$ = &#34;2&#34; OR i$ = &#34;3&#34; THEN 100GOTO 70100  y = 0: pl = 0110  IF i$ = &#34;1&#34; THEN 120IF i$ = &#34;2&#34; THEN 130IF i$ = &#34;3&#34; THEN 200120  REM Variables for Yates&#39; protocolos$ = &#34;LEFT&#34;side$ = &#34;OD&#34;fside$ = &#34;RIGHT&#34;m = 15test = 60os$ = &#34;LEFT&#34;side$ = &#34;OD&#34;fside$ = &#34;RIGHT&#34;m = 15test = 180: REM 180=45 MIN 3=5 MINGOTO 305200  CLSLOCATE 8, 20: PRINT &#34;(R)ight eye / (L)eft eye / E(X)it ? &#34;;220  side$ = UCASES(INKEY$)IF side$ = &#34;X&#34; THEN GOTO 70000IF side$ = &#34;R&#34; THEN side$ = &#34;OD&#34;: GOTO 250IF side$ = &#34;L&#34; THEN side$ = &#34;OS&#34;: GOTO 260GOTO 220250  os$ = &#34;LEFT&#34;GOTO 270260  os$ = &#34;RIGHT&#34;GOTO 270270  LOCATE 10, 20: LINE INPUT &#34;Set testing interval (minutes): &#34;;  step$IF step$ = &#34; &#34; GOTO 200m = (VAL(Step$) * 60)300  LOCATE 12, 25: LINE INPUT &#34;Set number of tests: &#34;; test$IF test$ = &#34; &#34; GOTO 300test = VAL(test$)305  CLSfile$ = LEFT$(l$; 3) + LEFT$(F$; 1) + LEFT$(s$, 2) + &#34;.inf&#34;data$ = LEFT$(file$, 6) + side$ + &#34;.x1&#34;OPEN file$ FOR RANDOM AS #1 darkinfo.lname = 1$ darkinfo.fname = F$ darkinfo.ssn = s$ darkinfo.test = STR$(test)PUT #1, 1, darkinfoCLOSE #1310  CLSLOCATE 8, 20: PRINT &#34;`Zero` instrument at maximum intensity&#34;LOCATE 10, 27: PRINT &#34;Cover patient&#39;s &#34;; os$; &#34;eye&#34;LOCATE 14, 26: LINE INPUT &#34;Press &lt; ENTER &gt; when ready&#34;;  q$CLSLOCATE 10, 14: PRINT &#34;Please standby - decreasing intensityto start point&#34;LOCATE 12, 30: PRINT &#34;Count down =&#34;OUT 890, 1: REM Turns: motor driver onFOR s = 1 TO si: REM Decreases intensity to start point c = c - 1 OUT 888, 129 GOSUB 4000 OUT 888, 128 GOSUB 4000 LOCATE 12, 44: Print cNEXT sOUT 888, 128OUT 890, 2320  CLSCLSTIME$ = &#34;00:00:00&#34;OUT 888, 129330  IF TIME$ = warn$ THEN GOSUB 10000IF TIME$ = light$ THEN 340 LOCATE 10, 28: PRINT &#34;** Bleaching &#34;; side$; &#34; **&#34; LOCATE 12, 27: PRINT &#34;Elapsed time = &#34;; TIME$ GOTO 330340  OUT 888, 128400  CLSREM LOCATE 12, 26: LINE INPUT &#34;Press &lt;ENTER&gt; to begin  test&#34;; i$OUT 890, 1500  CLSTIME$ = st$TIMER ON900  CLS1000 OUT 888, 1: REM Steps motor forward 0.45 degreesGOSUB 4000OUT 888, 16: REM Resets parallel portGOSUB 40001400 i = INP(889): REM Patient response triggerc = c + 1: REM &#34;Intensity&#34; counter - upGOSUB 6000LOCATE 6, 28: PRINT &#34;Testing &#34;; fside$; &#34; eye&#34;LOCATE 9, 25: PRINT &#34;Test number = &#34;; (y + 1); &#34; of &#34;; testLOCATE 13, 29: PRINT &#34;Intensity = &#34;; cd = cIF i = h THEN GOTO 2000: REM home i = 175 notebook i = 8IF c &gt;=4800 THEN GOTO 2000: REM 70000GOTO 10002000 SOUND 800, 1a$(y, 1) = RIGHT$(TIME$, 5)a$(y, 2) = STR$(c)2100 c = c - 1: REM &#34;Intensity&#34; counter - downOUT 888, 129: REM Steps motor backward 0.45 degreesGOSUB 4000OUT 888, 128: REM Resets parallel portGOSUB 4000GOSUB 6000LOCATE 13, 29: PRINT &#34;Intensity = &#34;; cLOCATE 9, 25: PRINT &#34;Test number 32  &#34;; *y + 1); &#34; of &#34;; testIF c &lt;&gt; INT(d * pct) THEN 21002200 p$ = STR$(TIMER)q$ = LEFT$(p$, 5)p2 = VAL(q$)IF (p2 - p1) &gt;= m GOTO 3100GOSUB 6000GOTO 22003000 STOP3100 p1 = p2y = y + 1______________________________________ 
    
     Clearly many modifications and variations of the present invention are possible in light of the above teachings and it is therefore understood, that within the inventive scope of the inventive concept, that the invention may be practiced otherwise than specifically claimed.