United States Patent [19][11]4,167,189

Tachi et al.

[45]

Sep. 11, 1979[54] INFORMATIONAPPARATUS FORTRANSMISSIONOFBY ELECTROCUTANEOUS
STIMULUS[57][75] Inventors: Susumu Tachi, Tokyo; Kazuo Tanie,
Yokohama, both of Japan[73] Assignee: Agency of Industrial Science &Technology, Tokyo, Japan[21] Appl. No.: 781,887[22] Filed:
Mar. 28, 1977
[30]
Foreign Application Priority Data
Apr. 26, 1976 [JP] Japan .................................. 51-48112[51] Int. Cl* ............................................... A61N 1/36

[52] U.S. C. .......................................... 128/421; 3/1.1[58] Field of Search ............... 128/404, 419 R, 419 C,
128/419 D, 419 B, 420, 421,422,423, 2.1 R, 2.1
Z; 3/1.1[56]

References Cited-

U.S. PATENT DOCUMENTS
3,747,605
3,791,373
3,817,254
3,860,009

3,869,661

Primary Examiner—Lee S. Cohen

Attorney, Agent, or Firm—Kurt Kelman

7/1973
2/1974

Cook ............................... 128/419 D
Winkler et al. ..
... 128/422 X

6/1974Maurer...........................* - - - - - 128/421

1/1975

Bell et al. .....

... 128/419 D

3/1975 Cataigne ....................... 128/2.1 R X.

ABSTRACTIn the transmission of information through the mediumof electrocutaneous stimuli, the data is generally transmitted by issuing signals in the form of pulse trains
which carry the information in terms of their frequencyof repetition, the duration time of the train of pulses, thepulse height and the pulse width. Different pulse sig
nals, on conveyance to the organism, generate thereon
one and the same magnitude of sensation when the
products of pulse widths multiplied by the squares ofrespective pulse heights are equal. By a procedure offirst measuring the cutaneous impedance of a given

subject, forwarding the measured value of impedance asa feedback for thereby controlling the pulse signal of
the information being transmitted so as to make con
stant the product of the pulse width multiplied by thesquare of the pulse height of the pulse signals and passing the controlled pulse signal to the subject, the magni

tude of sensation roused in response to any particularsignal is rendered constant at all times and therefore theinformation conveyed through the medium of a varying
collection of such particular signals can be correctlytransmitted to the subject.
3 Claims, 8 Drawing Figures

V/C
Converter

current

measurement
circuitvoltagemeasurement
circuitU.S. Patent Sep. 11, 1979

Sheet 2 of 6

pulse width

pulse heigh4,167,189

Fig - 2

-

- F-

-

(current i)-

Woltage V)|| |

||

||

.

||

.

pulse interval-Tstimulus-duration-time(IFH)

adjustment
informationtransmittion
by E.S.

U.S. Patent Sep. 11, 1979

4,167,189

Sheet 5 of 6

J? dInu
esind

JO?eu 608
18

4,167,189

1

APPARATUS FOR TRANSMISSION OF
INFORMATION BY ELECTROCUTANEOUS
STIMULUSBACKGROUND OF THE INVENTION

2
pulse height multiplied by the pulse width is constant.
The possible effect of cutaneous impedance upon thepulse signals can be eliminated and the transmission of
information by the pulse signals can be carried out accu
rately, therefore, by a procedure of preparatorily detecting the cutaneous impedance of the subject, control

This invention relates to an apparatus for transmis ling the pulse width or pulse height of the pulse signal insion of information by the medium of electrocutaneous accordance with the detected value so as to bring thestimuli adapted to rouse the cutaneous sensation of a 10 product of the square of pulse height multiplied by thepulse width to a constant level and applying the con
human subject.
For example, transmission of information through the trolled pulse signal to the electrodes.
The other objects and characteristic features of themedium of electrocutaneous stimuli has been adopted ina system wherein the operation of a prosthetic hand or present invention will become apparent from the demanipulator by its operator is facilitated by feeding scription given in detail hereinbelow with reference toback the sensation of touch or sensation of force to the 15 the accompanying drawing.
operator with the aid of a device adapted to convey
BRIEF DESCRIPTION OF THE DRAWINGS
feedback signals from the machine to the operator, in asystem which provides the blind or the deaf with a
FIGS. 1(A), 1(B) and 1(C) are graphs showing thesubstitutive visual or audio sensation and in a system of relation between the pulse height of the pulse signal andcommunication between two or more individuals under 20 the information transmission rate;environmental conditions which prevent normal com
FIG. 2 is a diagram showing the wave form of anelectric pulse train conveyed to the skin for generation
Such transmission of information through the me of electrocutaneous stimuli;
dium of electrocutaneous stimuli is generally effected
FIG. 3 is a diagram showing one embodiment of theby emitting signals in the form of pulse trains which 25 wave
form of a modified pulse;
carry the information in terms of their frequency of
FIG.
4 is a block diagram showing one embodiment
repetition, stimulus-duration-time, the pulse height (in of the apparatus
transmission of information accord
the form of either voltage or current) and pulse width. ing to the presentforinvention;
In the conventional system of this type for the transFIG. 5 is a block diagram showing in full detail themission of information, signals desired to be conveyed 30 multi-stimulator
involved in the apparatus of FIG. 4;
are simply converted into corresponding magnitudes of
FIG. 6 is an explanatory diagram of the operational
electric current or some other suitable electric phenom process
involved in the apparatus for transmission ofenon and are directly presented to the skin. Because of informationaccording to the present invention; andits anatomical nature, the skin is sometimes moistened
FIGS.
7
and
block diagrams illustrating otherwith perspiration and at other times is dry, causing a 35 embodiments of8theareapparatus
for transmission of infor
frequent fluctuation in the electrocutaneous impedance. mation according to the present
invention.
This means that the magnitude of sensation roused by afixed magnitude of electric current, for example, is
DESCRIPTION OF THE PREFERRED
likely to vary with time and occasion. This variation has
EMBODIMENTS
posed a problem in that it prevents the information from
The inventors, with a view to determining the effectbeing transmitted exactly.
An object of this invention is to provide an apparatus of a change in the cutaneous impedance upon the mag
for the transmission of information through the medium nitude of sensation roused on the skin by the pulse signalof electrocutaneous stimuli, which apparatus is capable in the transmission of information through the medium
of enabling any particular signal to rouse a fixed magni 45 of electrocutaneous stimuli, chose three adult subjects,
attached electrodes to the upper arm, fixed a standard
tude of sensation at all times.
pulse signal having a pulse width of 100 pisec and a
SUMMARY OF THE INVENTION
pulse height of 4.7 ma and varied the pulse width in a
To accomplish the object described above in accor signal being compared with said standard pulse signal
dance with the present invention, there is provided a 50 and randomly applied the standard pulse signal anddata-transmitting apparatus of the type having elec various pulse signals for comparison each 50 times totrodes adapted for attachment to the skin of a human the electrodes, with the duration of electrocutaneous
subject, applying pulse signals to the electrodes and stimuli limited to a fixed length of 2 sec, to determine
thereby rousing electrocutaneous stimuli and conveying whether the sensation roused by the pulse signal for
desired information to the subject, which apparatus 55 comparison and that roused by the standard pulse signal
comprises means for detecting the cutaneous impedance are equal or not. The results were as shown in theof the subject, means for controlling the pulse height graphs of FIGS. 1(A), 1(B) and 1(C) wherein the verti
and pulse width of the pulse signals of the information cal axis is graduated for information transmission ratemunication.

--

by a scale wherein 1.0 denotes a case permitting perfectdistinction between the standard pulse signal and thepulse signal for comparison and 0 denotes a case permit
ting absolutely no distinction between the two pulse
signals, and the horizontal axis is graduated for pulse
the electrodes.
It has been ascertained by the inventors that even height by a scale wherein 120 corresponds to 4.7 ma.
when a given pulse signals representing a specific item 65 FIG. 1(A) represents the data obtained where theof information has its pulse height or pulse width var pulse intervals are 100 msec, FIG. 1(B) those obtained
ied, it is perceived by a human subject as one and the where the pulse intervals are 50 msec and FIG. 1(C)same pulse signal insofar as the product of the square of those obtained where the pulse intervals are 20 msec.

being transmitted in accordance with the detected cuta
neous impedance so as to equalize the product of thesquare of the pulse height multiplied by the pulse widthand means for applying the controlled pulse signals to4,167,189

4
particular item of information desired to be transmitted
is carried on the pulse height (amperage or voltage) or
the pulse width, the pulse width or pulse height must be
controlled so as to keep the value of Formula (1), pref
erably Formula (3), constant in order that the magni
tude of sensation roused on the skin in response to the3
FIG. 1(A) indicates that, where the pulse width of asignal under comparison is fixed at 200 pisec, the pulse
signal can be distinguished perfectly from the standard
pulse signal when the pulse height is lower than about
65 or higher than about 105 and can hardly be distin
guished when the pulse height is between 80 and 85. It
also indicates that where the pulse width of the signal isfixed at 400 pisec, distinction between the pulse signal

signal may be kept at a fixed level.

First in case where the information desired to be

and the standard pulse signal can be perfectly obtained transmitted is carried on the magnitude of amperage,
when the pulse height is lower than about 45 or higher 10 the operation starts with measuring the impedance ofthan about 70 and can hardly be obtained when the the skin of the subject. When the measured value ispulse height is between 55 and 60.
applied to an exactly rectangular pulse, the result isThis trend also exists where the pulse intervals are obtained without going through integration, as shown
fixed at 50 msec as shown in FIG. 1(B). It is seen that in Formula (4).
where the pulse intervals are narrowed further to 20 15
msec (FIG. 1(C), practically the same trend is observed, though the difference between the pulse signal
under comparison and the standard pulse signal becomes clear.
As the result of the experiment described above, it 20 When the cutaneous impedance Z changes to Z', thehas been ascertained that two pulse signals rouse an compensation is obtained by changing the pulse width
equal magnitude of sensation on the organism when the T of the signal representing the data under transmission
products of their pulse widths (T) multiplied by the so as to satisfy the equation ZT=Z'T', namely, to asquares of their pulse heights (I) are equal.
value T' which is the quotient of ZT/Z'. In case where
P.T=k (constant)(1)

25 the wave form is deformed as shown in FIG. 3, thepulse width is controlled so that the value of Formula

will have a fixed value as described above.
The value I2 which is the square of the pulse height (3)More
strictly, this control is made so as to keep the(amperage) is proportional to the electric power where
the cutaneous impedance Z of the human subject is 30 value of Formula (5) constant.

assumed to be constant.
12To:ZPT=k(2)

wherein ZI2T denotes the energy which exists while theimpedance Z and the amperage I remain absolutely 35 Consequently, the pulse width T is controlled for thestationary during the period of pulse width T. When an electrocutaneous stimuli to be substantially constantallowance is made for possible variation in the magni regardless of any change in the cutaneous impedance.
tude of amperage during the period, then the relation of In the foregoing formula, Z(t) and i(t) denote the cuta
Formula (2) will be expressed more exactly as shown in 40 neous impedance and the amperage which vary relative
to time.
Formula (3).
Since the voltage v(t) is the product of Z(t) i(t), For
mula (5) may be replaced by Formula (6) where thevoltage v(t) is measurable.
45

wherein i(t) denotes current.
The apparatus for the transmission of information by
the present invention has been constructed on the basis
In case where ?he information is carried on the voltof the knowledge described above.
When a particular item of information is to be depos 50 age v instead of the amperage, the pulse width T is
ited on the pulse height (amperage), the change in the changed in proportion to the change of cutaneous impe
cutaneous impedance Z is measured in advance and the dance so as to keep the value of Formula (7), shown
measured change is compensated for by adjusting the below, constant.

pulse width T. When the information is to be carried on

the pulse width T, the change in the cutaneous impe 55
dance Z is measured in advance and the measuredchange is compensated for by adjusting the pulse height
I. This compensation permits the magnitude of sensa
When the cutaneous impedance Z changes to Z’, thetion roused on the skin in response to the signal repre
senting the specific item of data to remain constant and compensation is accomplished by changing the pulse
enables the data to be transmitted correctly despite width T to a new value of T' which satisfy the equation
T'/Z'=T/Z. When the wave form of the signal is depossible change in the cutaneous impedance.
When transmission of data is effected by rousing formed, accurate control of the pulse width T for thesensation on the skin of a subject by means of electric compensation can be obtained by replacing the values
stimuli, the signal as the medium of data is given in the 65 of v and Z with the values v(t) and Z(t) which areform of an electric pulse train of a suitable pulse interval variable relative to time as described above.
FIGS. 4 and 5 are block diagrams illustrating one
produced over a suitable duration time of stimuli asshown in FIG. 2. In the present invention, when the embodiment of the apparatus for the transmission of

4,167,189

5information by means of electrocutaneous stimuli ac
cording to the present invention, wherein the informa
tion to be transmitted is carried on the pulse height. The
embodiment will be described by assuming a casewherein the transmission of information is carried out inaccordance with the relation of Formula (6). In thecase, the value of “k” in the formula represents theinformation desired to be transmitted.

6of time corresponding to the pulse width T. This integrator 11 is provided with a switch adapted to control
the three states of integration, hold and reset, with thecontrol effected by means of the control signal issued by

the sequence controller 14. By the control signal fromthe sequence controller 14, an integration signal is forwarded to the integrator. Upon completion of the inte
gration, a hold signal is subsequently issued. At thesame time, the sequence controller 14 issues a start pulse

As the information is forwarded from the CPU (central processing unit) 3 to the multi-stimulator 4 through 10 to the A/D converter 12 so that the output of the inte
the data line (FIG. 5), it is selectively fed to the level grator is subjected to A/D conversion by the A/Dregister 16 (with the pulse height specified) and the converter 12. The data resulting from this integration,pulse width register, depending on the nature of the namely the stimulation energy
data. In this case, the allocation of the data to the tworegisters is accomplished through the medium of the 15
decoder 15 in accordance with the address signal forwarded through the address line. The information allocated respectively to the registers 16 and 17 are notimmediately processed to give outputs but are pro per pulse is fed back to the CPU 3.
cessed by the enable bit of the status register 18. To be 20 In the apparatus of the construction described above,
specific, when the enable bit is set to “1,” the clock when a stimulation energy “k” desired to be transmitted .
pulse generator 22 is started. Consequently the genera is fed as an input to the CPU 3 through a typewriter (nottor 22 issues a pulse to the mono-multi vibrator 21 and illustrated), there consequently are established fre
actuates the vibrator 21 to give rise to a pulse having a quency, pulse width and pulse height corresponding tocertain width, which is forwarded to the level register 25 this particular stimulation energy. When one electric
19 and the counter 20. Thus, the information received current pulse of the established conditions is forwarded
for temporary storage in the level register 16 and pulse as a test signal to the level register 16 and the pulse
width register 17 are transferred to the level register 19 width register 17 of the multi-stimulator 4, the status
and the counter 20 respectively. The data now in the register 18 actuates the pulse generators 22 and 23 andlevel register 19 is directly forwarded to the D/A con 30 the test signal is forwarded from the level register 19 toverter 24. On the other hand, the data received in the the electrode 2 via the isolator 5 and V/C converter 27.
counter 20 is deducted by the pulse from the clock pulse Since only one pulse is used in this case, virtually no
generator 23 which is operated by the bit of the status sensation is roused on the subject. The magnitudes ofregister 18. What is contained in the register 18 is de amperage and voltage of the test signal are measured, as
creased to “0,” a borrow signal is issued to the level 35 described above, by the current-measuring circuit 8 andregister 19 to clear what is contained in the register 19. the voltage-measuring circuit 9 and the product of their
The contents of the register 19, therefore, undergo D/A outputs is obtained by the multiplier 10, further inte
conversion for the length of time corresponding to the grated by the integrator 11, then subjected to. A/Dvalue set in the counter 20, with the result that the conversion by the A/D converter 12 and thereafter fed
multi-stimulator 4 produces as the output a pulse having back to the CPU 3.
Within the CPU 3, the value of A/D conversion thus
the amplitude stored in the level register 19 and a widthof the value designated in the register 17. This output is fed back is compared with the established value of en
applied to the isolator 5. The isolator 5 which is formed ergy by an operation such as is illustrated in FIG. 6. The
of a photo-coupler, for example, drives the battery pulse width of the electric current pulse of the signal
powered voltage-current converter 27 to apply an elec 45 desired to be transmitted is adjusted on the basis of thetric current corresponding to the stimulation signal to cutaneous impedance of the subject.
To be specific, when the parameters of pulse wave
the pair of electrodes 2 held in contact with or buried in
the skin 1 of the subject to whom the data is desired to form such as number of pulse waves and pulse width of
be transmitted. These electrodes may be either disc the stimulation energy are established in advance (1)shaped electrodes or needle-shaped electrodes which 50 and the data desired to be transmitted is fed (2), then
are known in the art. The circuit 8 for measuring the there is established a corresponding pulse IPE. The
amperage and the circuit 9 for measuring the voltage pulse height IPH of this pulse is calculated from theare respectively formed by a differential amplifier and preparatorily estimated value of cutaneous impedance.
an isolator. The amperage of the electric current pulse The resultant pulse is forwarded as a test pulse to theapplied to the electrode 2 is detected by using the differ 55 electrodes set on the subject (3). The pulse width IPW
ential amplifier of the current-measuring circuit 8 to of this initial test current pulse is calculated, for exam
amplify the voltage drop across the register 7 connected ple, in accordance with the following formula.
in series between the converter 27 and the electrode 2.
IPH=cVIPE(8)
The voltage of the electric current pulse is amplified
and detected by causing the differential amplifier of the 60
voltage-measuring circuit 9 to be connected to the elec wherein, c denotes a variable parameter.
The magnitudes of amperage and voltage of the elec
trode 2. The magnitude of amperage i(t) detected by thecurrent-measuring circuit 8 and the magnitude of volt tric current pulse forwarded to the subject are mea
age v(t) detected by the voltage-measuring circuit 9 are sured. The product of the magnitudes is integrated andforwarded through their respective isolators of, for 65 the result of the integration undergoes A/D conversion
example, photo-coupler type, to the multiplier 10 to be (4). The result of this conversion IE is fed back to themultiplied by each other. The output from the multi CPU to be compared with the initially set pulse IPE
plier 10 is integrated by the integrator 11 for the length (IPE—IE=IED), with the result that the difference

4,167,189

7
IED from the electric current pulse IPE desired to betransmitted (5). When the difference IED thus deter
mined is smaller than the allowable value e of the pulse

8
signal IPE desired to be transmitted at the comparator
30. The comparator 30 issues a pulse when the output of
the integrator 11 is greater than the signal IPE. Thispulse is forwarded to the level converter 31, in which it
is converted to a pulse signal of the prescribed level.
The output of the level converter 31 is applied to thestrength perception by the human being (5), this electric
current pulse is forwarded as the actual data to theelectrodes for a prescribed length of time, effecting thetransmission of data (6). When the difference IED hap clear terminal of the monostable multivibrator 25, withpens to be greater than the allowable value, the pulse the result that the output of the monostable multi-vibra
signal has its pulse height IPH changed once again and, tor 25 is cleared. Consequently, the stimulation electricin the resultant modified form, forwarded as a test pulse 10 current to the isolator 5 falls to 0, producing as theto the subject so as to find the measured value IE and output a pulse having an energy of the magnitude desig
determine whether or not the difference IED from thenated by the signal IPE. The integrator 11 functions toelectric current pulse IPE desired to be transmitted falls cause the rising portion of the output pulse of the mono
below the allowable value e. The correction of the pulse multi vibrator 25 to be reset with the signal which hasheight IPH is repeated until the difference decreases 15 been processed by the monostable multi-vibrator 29
below the allowable value. At the time that the differ
ence becomes smaller than the allowable value e, the(rear edge trigger type).
Now, the preceding embodiment will be described

electric current pulse resulting from the final correction with reference to concrete numerical values. It is as
is given as the signal for transmission of data to the sumed that the stimulation current which is the output
subject for a prescribed length of time. In this case, the 20 of the variable gain amplifier 26 is fixed at a pulse heightcorrection of pulse height is carried out in accordance of 5.0 mA, the cutaneous impedance (taken as consistingwith the following formula, for example.

of pure resistance elements) is fixed at 1 KQ and themagnitude of signal IPE is fixed at 30 erg. Then the
output Iout of the integrator 11 is expressed by the fol
25 lowing equation.
In case where the pulse width IPW is changed by
IPH=cVIPE—IE(9)

way of compensation instead of the change of pulse
height IPH, the pulse width is changed in accordancewith the following formula, for example, while theamplitude of the electric current is kept at its initial 30
2.5 × 10°t(erg)value. The modified value of the pulse width is forwarded to the pulse width registor 17. From this point
T denotes the interval of pulse and t the pulse
onward, the procedure applicable to the compensation wherein,
width.
by the change of pulse height will be followed.
So, the pulse width t is to be adjusted so that the
IPW= IPW-Ec(IPE—IE)(10) 35 difference between the value found by the foregoing

equation and the signal value IPE is brought to 0. That
is to say, the comparator 30 issues an output when thefollowing expression is satisfied.

The preceding embodiment has been described as
effecting the modification of pulse height or pulse widthby use of a computer operated on the digital basis. Al
2.50× 104T-30s.O
ternatively, the modification may be accomplished on
the analogous basis with the aid of exclusive circuits.
formula states that upon integration T=1.2×10-4
First, transmission of data as carried by the pulse This
sec=120
pus, the output of the integration circuit 11
height will be described.
exceeds
thetarget value IPE (=30 erg), at which time
With reference to FIG. 7, one pulse signal having
comparator 30 issues an output to clear the output of
preparatorily established pulse height, pulse width and 45 themonostable multi-vibrator 25, and that as the result
pulse interval is issued from the pulse generator 24 to the stimulation
current is brought down to 0. Thus, thethe mono-multi vibrator 25 provided with clear termi the
pulse
width
is
adjustednals. The output of the vibrator 25 is forwarded to the of 30 erg is given. to 120 ps when the target value
variable gain amplifier 26 and converted into a pulse
train having a pulse height to be established by an exter 50 Now, transmission of information as carried by thewidth will be described with reference to FIG. 8.
nal gain signal. The pulse train is forwarded to the isola pulse
In FIG. 8, the pulse generator 24 issues as the test
tor 5. The isolator 5 drives the battery-powered volt
age-current converter 27 to apply an electric current pulse one voltage pulse having prescribed pulse heightcorresponding to the stimulation pulse to the pair of the and pulse width. This test pulse is forwarded to the
55 isolator 5 through the medium of a variable gain ampli
electrodes 2 fastened to the skin.
The magnitudes of amperage and voltage of the elec fier 32, which causes the battery-powered voltage
tric current just mentioned are measured by the current amperage converter 27 to produce an electric current
measuring circuit 8 provided with an isolator and the corresponding to the test pulse signal and apply said
voltage-measuring circuit 9 provided with an isolator in electric current to the electrodes 2. The magnitudes ofmuch the same way as in the embodiment illustrated in amperage and voltage of the electric current are mea
FIG. 4. The output of these measuring circuits 8, 9 are sured by the current-measuring circuit 8 and the volt
multiplied by each other in the multiplier 10 and there age-measuring circuit 9 respectively. The outputs ofafter integrated by the integrator 11. As the signal for these measuring circuits are multiplied by each other bystarting this integration by the integrator 11, the rising the multiplier 10 and the resultant product is integrated

portion of the output pulse of the mono-multi vibrator 65 by the integrator 11. The subtractor 33 outputs the
25 is processed by the mono-multi vibrator 28 (front difference between the result of this integration and theedge trigger type) and forwarded to the integrator 11. electric current pulse corresponding to the signal IPE
The output of the integrator 11 is compared with the desired to be transmitted and the difference is processed

4,167,189

10

9by the rooter 34 to extract the square root thereof. The
square root of the difference is fed back to the variable
gain amplifier 32. The variable gain amplifier 32 issues
an output having a pulse height corresponding to the

GO TO 4004

output of the rooter 34.

CALL DELAY-continued
IF(IPH. G.T. 255) iPH=255
IF(IPH. LT. O) IPH=0-

CALL DAOUT (IPW, IPH, ICN, IPI, IST1)

The preceding embodiment will now be explained byusing concrete numerical values. It is assumed that themagnitude of signal IPE desired to be transmitted isfixed at 30 erg, the cutaneous impedance is fixed at 1
K?) and the pulse width of the pulse signal of stimula 10tion is fixed at 100 p.s. Similarly to the preceding em
bodiment, the output of the integrator 11 is expressed as

CALL DELAY
GO TO 10
STOP .
END

SUBROUTINE DELAY

DO 10 I-1, 10000
DO 11 J-1, 4

follows.
15

1110(IPH)2 × 103 × (100 × 10-6) × 107(erg)

DO 10 I= 1, 6000

wherein T denotes the cycle of pulse and IPH the pulse 20

10height. Consequently, the output of the subtraction

circuit 33 is expressed as follows.

The output of the rooter 34 is obtained as follows.

25 EXRDB=DRWC =DRST=
DRBA1 =DRBA2=DACST=
30 FPR1 =
PSW =
LKS=

The output of the amplifier 32 is adjusted so that theoutput of the rooter 34 will be brought down to 0. That
is to say, the adjustment is made so that the IPH isbrought to 5.5 mA (=5.5×10-3).
As described above, the apparatus for the transmis DAOUT6:
sion of information according to the present invention 35
eliminates the effect of cutaneous impedance and there
fore enables one and the same signal representing theinformation to rouse a constant magnitude of sensationon the skin of the subject at all times. Thus, the informa
tion can be accurately transmitted.
Now the program for effecting the present invention
by use of a computer, PAP 11/40, will be expressed by
the conventional Fortran computer language.
IPW = 2
HPI = 20
IST=2000
IPH = 100
EK=4.0
AIK=0.1
ICN = 1
ITPRM =5045

50IF(ICN. EQ. 0) ICN2=1
IST1=(IST-ICN2*10+IST*ICN)/IPI
10

CONTINUE

501

READ (5, 501) IPE
FORMAT(13)55

IPH=SQRT(EK*FLOAT(IPE)/FLOAT(IPW)IF(IPH. GT. 255) IPH=255
IT = IPE/ITPRMCALL DELAY2
CALL DAOUT6 (IPW, IPH, ICN, IPI, IE)
HED = IPE – IE

IF(IABS(IED). LT. IT) GO TO 4005
IF (IED. L.T. 0) GO TO 4102
IK=SQRT(FLOAT(IED)*AIK)
IPH = IPH-i-IK
IF(IPH. GT. 255) IPH=255
IF(IPH. L.T. 0) IPH=0

MIL:

65

IED=IABS(IED)

Ik=sqRT(IABS(IED)"AIK)HPH = IPH – IK

I- I
CONTINUE
RETURNEND.GLOBL.MCALL..V2.
.REGDEF
172416172410172414
1724.12177000177002174000177776177546MIC:

DAOUT6..V2...REGDEF.CSECT

MOV
MOV
MOV

SP, SPSAVE
LKS, LKSSAVPSW, PSWSAV

MOV
MOV
CLR

(3):#124, S1
Q#126, S2©;170404

CLR

LKS

MOV

#17, FPR1

CLR
CLR
CLR
CLR
CLR
CLR
CLR
CLR
CLR

R1
R2
DRDB
DRWC
DRST
DRBA1
DRBA2
DACST
COUNT

MOV
MOV
MOV
MOV
MOV
MOV
MOV

#20, Q#170400#INTDAC, @#354#340, G}{356#INTDMA, @#124#300, Q#125(R5)+, R1@(R5)+, R1

ASH
MOV

#10, R1
R1, R2

ADD©(R5)+, R1

MOV
MOVB
MOVB
ADD
MOV
MOVB
MOVB
MOV

R1, DRDB#0, DRDB#1, DRDB#140, R2
R2, DRDB#2, DRDB#3, DRDB(3)(R5)+, R1

TST

R1

BEQ

MIC

MOV

@(R 5)+, Rl

JMP

DAGO

MOV

©(R5)+, R1

ASH
ADD
MOV
MOV

GO TO 4004

4102

CONTINUE
CONTINUE
RETURNEND
SUBROUTINE DELAY2#6, R!
#62, R1
R1, DACSTG}(R5), IST