THE KELSH K-460 AND K-470 CAMERA SYSTEMS 
IN INDUSTRIAL PHOTOGRAMMETRY 
Joseph O Danko, Jr 
Danko Arlington, Inc 
ABSTRACT 
The Kelsh K-460 Universal Stereometric Camera 
was originally designed for the close-range 
technique of biostereometrics. During the 
development of this instrument, it was found 
to be extremely useful not only for medical 
purposes, but for a number of industrial 
purposes as well. 
The development of the Kelsh K-470 Terres- 
trial Camera followed the introduction of 
the K-460, under similar circumstances. 
K-470 was primarily developed for terres- 
trial photogrammetry, but was also found to 
be most useful in industrial applications. 
The 
A few examples of industrial uses for the 
Systems are described. One in particular 
gives an account of a wear test on an arti- 
ficial knee joint, or a tibial prosthesis. 
Although the end product was to be used in 
orthopedics, the manufacturer of the pros- 
thesis needed data on the amount of material 
removed by wear under simulated loading and 
cycling conditions.  Photogrammetry was 
found to be the best way to obtain this 
information. 
Suggestions are also made for other areas 
in industry where close-range photogrammetry 
might be useful. 
I. INTRODUCTION 
At the Kelsh Division, our fascination with 
the possibilities of close-range photogram- 
metry began during the development of the 
K-460 Stereometric Camera. The Kelsh K-460 
System was the result of a joint design 
effort with the Biostereometrics Laboratory 
of the Baylor College of Medicine. The K-460 
was originally developed for the technique 
of biostereometrics, however it was found 
to be extremely useful not only for medical 
purposes, but for a number of industrial pur- 
poses as well. 
The development of the Kelsh K-470 Terres- 
35 
trial Camera followed the introduction of the 
K-460, under similar circumstances. The 
K-470 was primarily developed for terrestrial 
photogrammetry, but was also found to be use- 
ful in industrial applications. 
During our investigation of the industrial 
market potential for close-range photogram- 
metry, we found it could be an extremely 
useful method (and perhaps the only way) 
to measure: 
Irregular shapes 
Moving shapes 
Inflated shapes 
Objects that are too 
too 
too 
too 
too 
too 
too 
hot 
cold 
soft 
delicate 
inaccessible 
toxic 
radioactive to touch 
MEASUREMENT OF WEAR ON A TIBIAL 
PROSTHESIS 
TT. 
One particular industrial application in 
which we were involved concerned the measure- 
ment of wear. The object in question was the 
lower half of an artificial knee joint, or a 
tibial prosthesis, made of high density poly- 
ethylene. The object could be considered as 
an "irregular shape", that was "too soft" to 
be easily measured by standard means. 
Research on behalf of several manufacturers 
had been under way for some time at the 
Massachusetts Institute of Technology, for 
developing optimum material combinations for 
both hip and tibial prosthesis.; The ball 
and socket configuration of the hip joint is 
spherical, and was therefore relatively easy 
to measure using conventional methods. But 
the tibial prosthesis presented a more diffi- 
cult measuring task. A typical tibial pros- 
thesis is shown in Figure 1, mounted in a 
knee joint. The upper convex component is 
an investment casting made from a steel 
alloy, with a high corrosive resistance to 
body chemistry. The lower concave component 
is made of a high density polyethylene, 
with the two concave surfaces articulate 
with the metal counter surfaces of the upper 
component. 
At the Department of Materials Science and 
Engineering at MIT, a unique testing machine 
had been developed for cycling the tibial 
prosthesis, as shown in Figure 2. The 
machine simulated the compound motions and 
pressures that are encountered by the human 
knee joint. The prostheses to be tested 
were potted with epoxy in machined aluminum 
blocks and mounted in the testing machine. 
Blood serum was used as a lubricant to 
simulate the rare synovial fluid of the 
human knee joint.  Incidentally, the research 
team found synovial fluid to be a lubricant 
so perfect, that the nearest approach to 
it would be wet ice! 
The average person cycles each of his knee 
joints about one million times per year. 
The MIT testing machine could cycle a sample 
tibial prosthesis about one million times 
per month, and under variable load conditions. 
After each test run in the machine, the 
change of shape of the concave sockets had