In re of your letter of Nov./9/32 we have forwarded the blood transfusion apparatus under separate cover. It is desirable
that the knowledge of the mechanism and principle of this instrument be limited to as few trustworthy individuals as possible
for our protection in the disposition of the instrument. However, we prefer that you handle the instrument if satisfactory
arrangements can be completed because of the lowered cost, increased availability to the profession, and your general reputation
This instrument, designed by the writers, has proven clinically to be entirely satisfactory and is believed by able clinicians
here to be the best and most practical syringe transfusion method at the present. First, because the instrument can be manufactured
of finest materials at an extremely low cost enabeling a popular selling price. Second, the only breakable and necessarily
replaceable part, the syringe, is readily available. Third, because it is operated by a simple push-pull notion of the syringe
piston, only. Fourth, complete instrument consists of the seven parts readily assembled requiring no mechanical knowledge.
Fifth, instrument can be packed in a sterilizing case about 6" x 2" x 1". Sixth, fragmentation of red blood cells
by valve mechanism practically negligible. Seventh, shortest blood course outside of body of any syringe instrument on the
market. Eighth, no dead space in instrument or valve mechanism where clotting may initiate. Ninth, simplicity of operation
increases rapidity of flow thus diminishing possibility of clot formation.
The instrument consists of a sleeve-valve and a case to contain a 10 c.c. syringe. The valve consists of a piston containing
one part communicating with the syringe tip at its upper end; and a sleeve containing two parts, the upper for donor and the
lower for the recipient. A taper pin through the sleeve and piston limits the up and down motion of the piston and thus insures
the accuracy of the approximation of the port in the piston with that of the donor in the extreme up position and that of
the recipient in the extreme down position.
The syringe case merely serves the purpose of stabilizing and holding rigidly the syringe barrel and also of fixing the syringe
tip into the standard Luer opening ground into the top of the piston.
To prevent the possibility of the reversal of flow it is necessary that the valve move before the syringe plunger begins to
move in an opposite direction. To insure this two springs are used to increase the friction between the syringe plunger and
the syringe barrel over that of the sleeve-valve. In actual clinical trial this has proven unnecessary in pumping a fluid
as viscid as blood. But this safety device acts as an additional guard against this possibility.
After assembling the instrument as per directions enclosed in forwarded package, to operate, merely clasp the cylinder of
the sleeve valve by the left hand and hold steadily and operate the syringe plunger with the other hand. In use, the cylinder
of the sleeve-valve is lubricated with sterile mineral oil. The system may be filled with sterile citrate or normal saline
The model in its present form is crude and merely illustrates the principle but even in its crudeness it has clinically operated
successfully. Several improvements and suggestions are shown on the accompanying diagram.
Thanking you in advance for your kind consideration and hoping to hear from you at your earliest convenience we remain,