US 2212334 A
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G. W. WALLERICH Aug. 20, 1940.-
CATHETER Filed Aug. 15, 1936 KIDNEY v UIPE 75/? R 1 m v M cel lulozzzc' Ma fer: a!
a a Maierv'al Mr W i .m M m w Patented Aug. 20, 1940 CATHETER George W. VVallerich, River Forest, 111., assignor to V. Mueller & 00., tion of Illinois Ghicago, 111., a corpora- Application August 15, 1936, Serial No. 96,189
This invention relates Ito improvements in catheters and their mode of manufacture, especial reference being had to small appropriately flexible tubing and to ureteral catheters made therefrom.
l-leretofore, such catheters intended for the taking of specimens'of urine from the kidneys, the ureter and the bladder have been made by Winding silk on a small wire mandrel and then coating the silk with varnish or the like before removing the mandrel. Such catheters have been superficially opaqued for X-ray purposes by Supplying bismuth powder or the like to the varnish. But such catheters lack durability; they do not stand heat well; are not easily sterilized; and they lack desired smoothness.
I am also aware that cellulosic tubes have been made by extruding plastic material from a press; but I have never known of catheter tubing or any kind of tubing fit for ureteral or urethral catheterization being thus made; and I am not aware of X-ray opaque material ever having been mixed with any such extrusion material for any purpose whatever.
The main objects of this invention are to provide a better and safer catheter; to provide resiliently flexible catheters better adapted to withstand sterilization, especially by boiling or other application of heat; to provide smoother surfaced catheters, especially of small gauge; to
provide a nonabsorptive catheter; to provide cellulosic catheters and especially such devices adapted to cast X-ray shadows during use; to
provide for calibration of such catheters, both 35 for direct surface reading and also for X-ray observation; to provide for extrusion manufacture of Y-ray opaque catheter tubing; and to provide for such opacity calibration of catheters as to render X-ray shadows readable in terms of linear measurement.
This invention is illustrated by the accompanying drawing in which: Figure 1 is a perspective view of a finished catheter. 45 Fig. 2 is a diagrammatic view of the catheter in use with appropriate anatomical structures indicated in dotted outline.
Fig. 3 is a cross section of the catheter tubing, to show impregnation of the cellulosic wall with 50 bismuth powder or other X-ray opaque material.
Referring to said drawing the catheter l consists of a thin tube about twenty-six inches long having cellulosic walls 2 impregnated with bismuth powder indicated at 3. Said catheter has inlet openings 4 and 5 at or near one end; and the opposite end is open as at 6. The external diameter of the catheters ranges from 1.5 mm. to 5 mm.
The X-ray opacity of the walls 2 is varied at regular calibration intervals or points 1, as by appropriate application of bismuth paint in finishing the catheter. This may serve also for direct visual indication of linear measurement, for which purpose the paint may be specially pigmented if desired.
Suitable catheter tubing may be made by first mixing bismuth powder with appropriate cellulosic material, and then extruding the plastic compound ina manner generally understood in the tube moulding art. Various degrees of heat and pressure may be applied, depending upon the specific quality of the plastic .used. More or less of said powder may be used according to the degree of opacity desired.
The temperature range depends upon the exact make of the compound used and provided that the material is sufliciently plastic for tubular extrusion. This is a factor which can best be adjusted from time to time as the process is carried on,
The desired flexibility and resilience of the tubing may be attained by due selection from'a well-known quality range of said material. Various cellulose derivatives are adapted for my use, but I especially prefer cellulose acetate.
It is to be understood that some of the details set forth may be altered or omitted without departing from the spiritof the invention as defined by the following claim:
The method or making a thin walled small gage flexible catheter adapted for bladder and kidney exploration which consists in extruding a plastic cellulosic material through a tubular molding die and at uniform brief intervals forcibly injecting into the stream of said material as it is being molded a small quantity of similar material impregnated with X-ray opaque material. 1
GEORGE w. WALLERICH.