A hemicapillar plate dialyzer comprising blood plates and dialyzer plates, with semipermeable diaphragms between said plates, provided with means to achieve a laminar flow of blood and a turbulent flow of the dialyzing solution by using a number of interrupted linear profiles on dialyzing plates and linear uninterrupted profiles on blood plates of rounded cross section, said dialyzing and blood plates being made of material of different hardnesses, with means for clamping said plates, and for the supply and removal of blood and of the dialyzing solution.

BACKGROUND OF THE INVENTION 
This invention relates to a hemicapillar plate dialyzer, made of plastic 
materials, the active plates thereof securing on one side a turbulent flow 
of the dialyzing solution and on the other side a laminar flow of blood, 
whereby the supply and removal of both media are guided so as to secure a 
uniform filling of contact surfaces of the plates without forming static 
zones. 
The dialyzer is the main part of a system called an "artificial kidney" for 
the treatment of failures of the kidneys in cases where the kidney 
function fails due to some injury, due to toxic harm, or due to a sudden 
or chronic inflammation. Without the normal function of the kidney due to 
poisoning by nitrogenous compounds, or due to the accumulation of 
potassium or of other body liquids, the patient dies. 
In such cases the equilibrium of the internal constitution of the organism 
of the patient may be restored by hemodialysis by means of a dialyzer of 
the coil type, the plate type, or of the capillary type, the dialyzer 
acting as a filter and eliminating from the human body products of 
nitrogen metabolism and adjusts the volume of body liquids and 
electrolytes. 
A disadvantage of known dialyzers is the substantial screening of the 
semipermeable diaphragm, which has to be offset by an increase of the 
overall weight of the dialyzer; further drawbacks reside in the 
unfavorable hydrodynamics of the flow of blood and of the dialyzing 
solution. Thus along the blood channels on the diaphragm there may be 
formed a stagnant slowly flowing limit layer of blood, such layer being 
thicker the slower the blood flows. This means that molecules of the 
offending materials have to pass not only through pores of the 
semipermeable diaphragm, but must overcome also the resistance of the 
stable layer of liquids on both sides of the diaphragm. The inlet and 
outlet of blood and of the dialyzing solution does not always insure with 
known solutions a full utilization of the contact surfaces, and static 
zones are created, which may cause an agglutination of blood. There are, 
furthermore, problems with the tightness of the whole system of the 
dialyzer, where rather high press forces are required in order to secure 
the tightness of the system; this entails the danger of breaking the 
relatively fragile diaphragms. The problem of tightness of the whole 
system results from the fact that the plates are made of materials of 
equal hardness, with inaccuracies of manufacture. A consequence thereof is 
that the plates do not mutually adjust in shape even though a high press 
force is used in the system. The high press force has to be compensated 
for by a more complex construction of the dialyzer, which results in a 
higher weight of the dialyzer. For this reason, high demands are made on 
dialyzers and on their arrangement, namely; 
1. The effect of hemodialysis has to be satisfactory, even for small 
amounts of blood in the dialyzer. 
2. The resistance to blood flow has to be as low as possible in order that 
a blood pump shall not be required. 
3. The residue of blood in the dialyzer after treatment of the patient 
should be so small, that it would not be required to supply the patient 
with compensatory blood, thereby overcoming the danger of contracting 
jaundice or hepatitis. 
4. The attendant of the artificial kidney should be protected from contact 
with blood or with the dialyzing solution, also to prevent any 
transmission of jaundice or hepatitis. 
5. The overall weight of the dialyzer should be as small as possible, and 
its components should be capable of being mass produced in order that it 
shall be used only once to prevent any danger of cross infection. 
6. The passage of blood should be laminar, and the passage of the dialyzing 
solution should be turbulent, and should be uniform in both the 
longitudinal and transverse directions in order fully to utilize the 
contact surfaces without the creation of static zones. 
7. The dialyzer has to form a part of a closed system which includes the 
patient. 
8. In order to achieve an effective cleaning of blood the dialyzer has to 
consist of a selectable number of similar components assembled by a simple 
manipulation. 
9. The diaphragms have to be securely mounted in the system, without undue 
stress, in order to reduce the danger of breakage. 
10. The dialyzer must be perfectly tight and its arrangement should prevent 
any direct contact of blood with the dialyzing solution. 
SUMMARY OF THE INVENTION 
It is an object of this invention to provide a hemicapillar plate dialyzer 
which meets the above enumerated requirements to a high degree. 
The hemicapillar plate dialyzer according to this invention comprises blood 
plates and dialyzer plates separated by a diaphragm, the dialyzer plates 
being provided on their surfaces, for obtaining a turbulent flow of the 
dialyzing solution, with linearly arranged extending interrupted supports 
of advantageously assymetric shape on both sides, and the blood plates 
being provided with linear protruding rounded uninterrupted profiles for 
obtaining a laminar flow of blood, a semipermeable diaphragm being 
inserted between said plates. The plates are made of plastic materials of 
different hardnesses, the projecting supports and the rounded profiles of 
the plates being connected to distribution channels with a gradually 
narrowing profile from the inlet of the liquid to the end of its track, 
thus securing a uniform filling and removal of liquids to and from contact 
surfaces of the plates along the whole surface of the blood and dialyzer 
plates without the danger of the creation of unwanted stagnant zones.

DESCRIPTION OF PREFERRED EMBODIMENTS 
Turning now to FIG. 1, the dialyzer as shown comprises an arbitrary number 
of blood plates 4 and of dialyzer plates 2 with a semipermeable diaphragm 
6 inserted between successive pairs of plates 2 and 4. The dialyzer 
operates advantageously on the counter-current principle, and is provided 
with means to connect it to a source of a dialyzing solution on one side, 
and means to connect it to the blood circulation system of a patient on 
the other side. 
The system comprises a number of modules, each module consisting of a blood 
plate 4 (FIG. 5) with uninterrupted, rounded, extending longitudinal 
profiles 5 securing a laminar flow of blood, and of a dialyzer plate 2 
(FIG. 4) with a number of assymetrically arranged point supports 3, which 
may have a shape such as shown in any of FIGS. 6a, 6b, and 6c, and 
semipermeable diaphragm 6 inserted between plates 2 and 4. Supports 3 
secure a turbulent flow of the dialyzing solution. By stacking a 
predetermined number of modules and by using closing plates 11, there is 
provided a dialyzer system with a desired number of standard components 
with a predetermined active surface area. 
The diaphragm 6 shown in FIG. 7 is, prior to insertion between the active 
plates 2 and 4, preformed to a profile corresponding to the active plates, 
thus preventing unwanted wrinkling of its circumference. The preforming of 
the diaphragm 6 mainly prevents the possibility of its breaking upon the 
clamping of modules between the closing plates 11 of the dialyzer. 
The circumferential sealing surface 8 of the blood plate 4 is flat, and the 
circumferential surface of the dialyzer plate 2 is formed as a twin 
labyrinth or multi-ribbed structure 9 or vice versa. This substantially 
reduces the projected sealing surface, thereby reducing the clamping force 
required for tightening the whole system. The possibility of a rupture of 
the diaphragm is also reduced, and any unwanted contact of blood with the 
dialyzing solution is prevented. 
By its arrangement the hemicapillary plate dialyzer according to this 
invention substantially reduces the thickness of the blood layer, thereby 
creating a many times thinner barrier for diffusing compounds than is 
possible with known systems. The thin layer of blood film results in good 
hydrodynamics of blood flow, so that the diffuser may be used in a 
predominant number of cases without a blood pump, thereby eliminating a 
substantial stress upon the blood circulation system of the patient. 
Good hydrodynamics of both media in the hydrolyzer according to this 
invention are obtained by accurate profiles of active plates 2 and 4, 
which can be reproduced in manufacture, whereby a uniform filling of the 
contact surfaces of the plates is secured by distributing channels 7 of 
plates 2 and 4. Channels 7 are gradually narrowed from the inlet of the 
media to the end of the respective tracks, and thus insure a uniform 
filling of the surfaces of plates 2 and 4 along the whole blood and 
dialyzer surface without the danger of creating unwanted stagnant zones. 
The small blood volume in the dialyzer according to this invention, the low 
resistance to its passage through the dialyzer system, and the small 
residual volume of blood after dialysis is finished, reduces the work 
required of the patient's heart, permits a reduction of the pressure drop 
in the dialyzer, thus simultaneously reducing ultrafiltration and 
traumatization of red blood corpuscles. 
The assembled modules of active plates 2 and 4 of the dialyzer according to 
this invention as shown in FIGS. 2 and 3, which are separated by a 
diaphragm 6, are forcibly clamped together between closing plates 11 the 
outer surface of which is of a lattice design, by means of bands 13 (see 
FIG. 2), said bands 13 being arranged spaced from each other both in the 
longitudinal and transverse directions in order to secure a perfect 
tightness of the system. 
The closing plates 11 are provided with extensions 12, in which nipples are 
provided for the inlet and outlet of blood and other nipples are provided 
for the inlet and outlet of the dialyzing solution. In FIG. 1 one of the 
media (blood or dialyzing solution) is depicted by dark arrows as entering 
and leaving the dialyzer at a first pair of opposite corners, and the 
other of the media is shown entering and leaving the dialyzer by the other 
pair of opposite corners. At least some of the opposite extensions shown 
at 14 in FIG. 3, may be somewhat inclined toward each other in order to 
create a prestress for clamping the dialyzer by bands 13 and thus to 
increase the clamping force in these exposed places. By this solution the 
tightness of the whole dialyzer system is better secured and its weight 
reduced, with advantages of economy, manipulation, storing and destruction 
by burning. 
The active dialyzer plates according to this invention are advantageously 
made of plastics of different hardnesses, so that in case of clamping the 
modules made thereof between closing plates a mutual forming of the plates 
by adjustment of the material of the active plates along the plate 
interfaces is accomplished, whereby inaccuracies of manufacture of 
individual parts are also adjusted. Simultaneously, a reduction of weight 
is achieved due to the smaller clamping force required and a better 
maintenance of tightness of the system over a normal storage period. 
In the last manufacturing operation the plate dialyzer according to this 
invention is forcibly clamped by means of bands 13 (FIG. 2) made of 
plastic material, the bands being advantageously provided with 
reinforcements of glass or graphite fibers, thereby preventing their 
elongation in case of dynamic stresses and maintaining the tightness of 
the system over long periods of time. This construction also contributes 
to a reduction of weight of the dialyzer with all the advantages attendant 
thereupon. 
The plate dialyzer according to this invention fulfills all conditions for 
an effective hemodialysis, and provides perfect reproducibility in mass 
production, that bringing about substantial advantages in economy and 
health service. 
The dialyzer of the invention may be used to advantage not only for 
hemodialysis, but, by changing the diaphragm of the dialyzer, it may also 
serve as an oxygenator for breast surgery, in case of a sudden need 
therefor, and may be used in laboratories and industry for filtering, 
ultrafiltering, osmosis, reverse osmosis, separation of analytically 
dispersed materials, and the like. 
Although the invention is illustrated and described with reference to a 
single preferred embodiment thereof, it is to be expressly understood that 
it is in no way limited by the disclosure of such single embodiment, but 
is capable of numerous modifications within the scope of the appended 
claim.