ITEM No. 24 
FILE No XXXIII-2 
COPY No. 122 
PORTABLE CATHODE-RAY 
ELECTROCARDIOGRAPH. 
COMBINED INTELLIGENCE OBJECTIVES 
SUB - COMMITTEE PORTABLE CATHODE-RAY ELECTROCARDIOGRAPH. MODEL EK08 &/. 
(Technological Physics Laboratory Karajan, Vienna). 
Reported by 
PAUL CHERNEY. let Lt. A.C. 
AIR DOCUMENT RESEARCH CENTER. 
CIOS Target Number 2V1*27 
Medical 
COMBINED INTELLIGENCE OBJECTIVES SUB-COMMITTEE,0-2 DIVISION, 
USFET (Rear) APO 413. TABLE OF CONTENTS 
SUBJECT PAGE 
1. Introduction , 3 
2. Target 3 
3. Investigation 3 and 4 - 
4. Summary 4 
5. Use and purpose of apparatus 4 
6. Function of apparatus 5 
7. Registration 5 and 6 
8. Net connection 6 
9. Compensation for Interferences 6 and 7 
10. Construction 7 
11. Servicing 7 and 8 
12. Potential Applications 8 and 9 
13. Technical Data 9 and 10 
PERSONNEL: 
1st Lt Paul Cherney, A.CL Air Doc Research Center. PORTABLE CATHODE-BAY ELECTROCARDIOGRAPH. MODEL EKGS 21. 
1. INTRODUCTION. 
At the occasion of the ADRC team's visit to Vienna in 
September 1945, it was established that during the early 
months of 1945, Siemens and Halsfce had installed a test 
laboratory in Vienna which was engaged in the design and 
subsequently in the manufacture of a portable Electro- 
cardiograph unit to be used extensively by the Luftwaffe. 
2. TARGET. 
The investigation of the target revealed that such 
an establishment operated under the name of: 
IMG, WOLFGANG VON KARAJAN, 
LABORATORIUK PUER TECHNISCHE PHYSIK, 
WIEN 50, WISDNEH HAUPTSTRASSE 63, 
3. INVESTIGATION. 
On location, nothing but the empty building could be 
found and the interrogation of the porter at the premises 
indicated that the Russian occupying forces had evacuated 
all material which was left behind. Karajan, the nominal 
owner and director in charge of the laboratory had dis- 
appeared shortly before the Russians entered Vienna. He 
was supposed to have been actively engaged in Nazi Party 
affairs. 
Eventually contact could be established wixh the former 
secretary, a Miss Fridtum, and Karajan's brother-in-law, 
Mr.Budeschowski. At the apartment of Budesohowski four 
units of the Cardiograph apparatus were found, one of 
which was removed and sent to USAFE (Main) at Wiesbaden 
for conveyance to the surgeon-general's office at Washing- 
ton, D.C. 
It was also ascertained that Karajan had gone to 
Grundlsee (Oberdonau) and a visit was made to his horns 
there without success, inasmuch as he had.left for Lins. 
The matter was turned over to Capt Vorfc of USDIK (USPA) 
at Gouhden, who was requested to follow through on this case and If possible collect available data pertaining 
to: 
a. The actual use of the Electrocardiograph by the 
Luftwaffe. 
b. Results obtained. 
c. Practical applications In connection with aero- 
medlcal problems. 
4. SUMMARY. 
While no figures oh production and costs could be 
established, the Interrogation of Miss Frldtum and Mr.Bud- 
eschowskl revaled that the OKL considered the apparatus 
a great Innovation. The first shipments of machines were 
found to be very satisfactory and large orders were ex- 
pected. While no Information concerning similar American 
or British equipment was available to ask pertinent 
questions. It was believed that the Information obtained 
and submitted, herewith In this report would prove sufficient 
to enable expert personnel to evaluate the respective ad- 
vantages of the model EKG-S 21 which will be available for 
Inspection at the Surgeon-General’s office at Washington, 
D. C. 
5. USE AND PURPOSE OF APPARATUS. 
The desire to register Electrocardiograms not only 
photographically but also to follow them with the naked 
eye,, led to the construction of the new Cathoderay- 
Eleotrocardlograph, Model EKO-S 21. With the aid of this 
apparatus It became possible FOR THE FIRST TIME to recog- 
nise Interesting changes of the Electrocardiogram during 
the actual origin and poourence and also to retain them 
photographically. 6. FUNCTION OF THE APPARATUS. 
The graphic Image of the visible curve of the Electro- 
cardiogram takes place on the scope of a cathoderay-tube. 
On this scope, facing the observer, and as a consequence 
of clashing electrons, a closely defined light spot appears 
drawing the Electrocardiographic curve. In order to con- 
vey to the observer the impression of a closed curve, 
the scope of the Cathode Hay Tube is coated with a post- 
lurainar layer. The motion of the light spot takes place 
in such a manner, that it moves from left to right across 
the center of the scope, thus drawing the curve until it 
gets to the extreme right edge from which position it 
automatically Jumps back to the left edge, from where it 
continues registering. The post-lumlnar effect of the 
scope is calculated in such a way that the drawn curve 
has faded away before the light spot actually reaches the 
left edge. IN THIS WANNER A CONTINUOUS EKG TRACING pre- 
sents Itself to the naked eye. 
FRONT VIEW 
7. REGISTRATION. 
A second Cathode Ray Tube placed Inside the apparatus 
serves the purpose of photographically registering the 
electrocardiogram on a film-strip passing it by way of a 
special transport-mechanism. Through the use of two 
separate tubes it is possible to observe the EKG-traclng without Interruption. The registration can also be 
started or stopped at will by simply pressing a button. 
The film transport Is accomplished by a synchronous 
motor. In this manner the time Indicator can be elimin- 
ated because the number of revolutions remains constant 
in the synchronous motor. The time markings are already 
Incorporated In the sensitized emulsion of the EKG- paper 
and are visible when developed. The usual time Inter- 
val of 0.05 seconds between two adjoining lines was es- 
tablished. Every tenth line Is a heavier one which facili- 
tates the counting of larger intervals on the paper. 
To compare the relative vertical range of the curve, 
a calibration of 1 millivolt can be photographed right on 
the film. 
8, NET CONNECTION. 
The necessary current for the operation of the appara- 
tus Is taken right from the net. No batteries are re- 
quired, which In turn provides for a minimum of servicing. 
As an added safety-measure, the net connection Is carried 
through a transformer. Standard types are constructed 
for use with alternating current. If direct current Is 
to be used, an additional transformer Is to be applied. 
On special request, battery units can also be furnished 
If electric current Is otherwise not readily available. 
9. COMPENSATION FOR INTERFERENCES. 
The most disturbing Interference In the course of 
electrocardiographic processes Is the effect of alternat- 
ing fields (of the current of the net connection) upon the 
patient. This expresses Itself In the well-known swelling 
savy zero line of the electrocardiogram and the deformation 
of the curve notches. In the same manner, knots of fine 
caliber disappear In this disturbance. To eliminate this 
short-coming, It Is recommended to apply a safety screen 
to minimise these Interferences, 
Insofar as the EKGS apparatus Is concerned, all these 
Interferences are eliminated through a special compensa- 
tion switch eliminating these disturbances right at the 
Initial phase. It was thus accomplished to completely eliminate the Influence of outside (electric) fields In 
a most practical manner, and to obtain clean-cut curves 
even under most unfavorable conditions. 
10. CONSTRUCTION. 
The entire mechanism Is placed In a metal container. 
The front view presents the observation scope and the 
necessary servicing knobs, which are furthermore protected 
by Individual hoods In case the machine Is to be moved 
from one place to another. The registration devices 
with:the magazines are placed at the rear of the machine, 
and are easily accessible through lifting a cover at the 
back. This facilitates greatly the Insertion and manip- 
ulation of films. Incidentally, all these manipulations 
can be executed In broad daylight, eliminating the necessi- 
ty of dark roo"*s. 
REAR VIEW 
11. SERVICING. 
The operation of the EKG-S apparatus is quite simple 
and actually consists only of the adjustment of the knobs 
for the light spot, the adjustment of the vertical range 
of the EKG- curve as well as the manipulation of the spped 
the light spot Is moved about the scope bf the -cathode-ray 
tube. The unit Is constructed In such a manner that no 
harm can be caused by Improper manipulation. This Is supposed to be a considerable advantage on the part of the 
CATHODE-RAY ELECTROCARDIOGRAPH above the conventional cord 
type electrocardiograph. 
12. POTENTIAL APPLICATIONS. 
The obvious advantage of easy transportability is . 
of primary importance to the practising physician. Another 
point is the easy method of manipulation. When using the 
EKGS Model Mo 21, the doctor will often find himeelf in 
the position to make a spot diagnosis on the basis of 
Just viewing the heart tracing directly at the bedside 
of the patient, rather than to postpone a decision depend- 
ing upon the ultimate development of the film. Generally 
speaking, it will be found in many oases that the physician 
will be able to refrain from taking photographic pictures 
altogether. This particular feature makes the EKGS 
apparatus particularly useful in connection with mass 
examinations or tests related to aero-medical or sports- 
medical phenomena. 
The direct viewing of the EKG-traclng with the naked 
eye represents in itself an entirely new range of various 
potential applications. First of all, the apparatus will 
be extremely useful when tests or clinical observations 
have to extend over any length of time, in the course of 
which electrocardiographic control is desirable or necess- 
ary. In such cases, a precise and immediate observation 
of heart phenomena can be accomplished. Furthermore, the 
opportunity is given to retain distinct phases of the 
observations photographically. 
The unit will enable the physician to determine 
variable changes in the P.R,-Interval, clots and widenings 
of the QRS complexes and distortions and their respective 
appearances as a consequence of narcotic damages or myocardlo- 
damaged patients during the operation RIGHT AT THE VERY MOMENT OF THEIR APPEARANCE. This In turn will enable 
the physician to avoid a dangerous Intensification, and 
through proper measures, eliminate dangerous consequences. 
The average type electrocardiograph actually only permits 
determining the occurring damage AFTER SUCH DAMAGE HAS 
TAKEN PLACE, because one cannot observe the EKG-traclng 
at the moment of Its origin because one has to wait In 
each Instance for the complete development of the film 
before a decision can be made. 
Thus, for Instance, the condition of the conduction 
system of the heart during the Insulin shook, the develop- 
ment of heart paroxysm or even rare extra systoles, can be 
observed and the effective efficiency degree of theraputlc 
relation can be determined In an exact measure even In 
connection with heart remedies administered perorally. 
An excellent application of the EKGS, apparatus Is the 
determination of chest disorders, because while tapping 
the chest with the thoracallc electrode, the scope will 
show the EKG curve, and the necessity of taking pictures 
and developing the same can be eliminated. Final refer- 
ence can also be made to the pictorial representation of 
the electrocardiogram for lecture purposes. 
13. TECHNICAL DATA. 
MEASUREMENTS: 270x610x300 mm. 
WEIGHT: 25 kg. 
DIAMETER OF VIEWING SCOPE: 70 mm. 
AMPLIFIER: 4 stages with constant mainten- 
ance of timing, full net connec- 
tion, compensation switch for 
Interferences, variable volume 
control, 
REGISTRATION SURFACE: 35 mm paper positive film In 
rolls up to 15m length with 
longitudinal and vertical line 
raster. TIME MARKING-: 0.05 seconds between two neigh- 
boring lines. Every 10th line 
appears heavily enlarged, 
REGISTRATION SPEED: 38 mm per second. 
VOLTAGE: 110/220 Volts AC. 
PERIODS: 50 Ho. 
STANDARD ACCESSORIES: One magazine for unexposed film, 
one magazine for exposed film, 
one spool EKGS registration paper, 
three plate electrodes, one net 
cable, one contact cable for 
connection with the patient, and 
Instruction sheet.