Patent Application
20110139704
The present invention relates to a blood dialyzing apparatus in which waste materials in blood can be removed through a membrane located between flowing blood and a dialysis solution, and more particularly, to a blood dialyzing apparatus which is constructed to enhance the efficiency of dialysis by alternately increasing and decreasing the pressure of the blood and the dialysis solution, respectively.
If kidney functions entirely fail or only some parts do, electrolytes in the body become unbalanced and in addition waste materials accumulate in the blood instead of being discharged out of the body together with the urine. As a way of treating this renal failure, an extracorporeal blood circuit formed by using a blood dialyzing apparatus is broadly used. The equilibrium of the electrolyte balance has been promoted by discharging the waste materials from the blood based on the simultaneous operations of the principles of diffusion or filtration.
The blood dialyzing apparatus is normally constructed to discharge waste materials from the blood by using a blood dialyzing filter equipped with a membrane in a housing in order to move the waste materials across the membrane located between the blood compartment and the dialysis solution compartment.
There are two kinds of membranes in general, a flat sheet type and a hollow fiber type. The most widely used is the hollow fiber type which is made up of a bundle of hollow fibers installed inside the cylinder-shaped housing and is potted with resin layers on both ends. The reason is that the surface of the membrane in contact with the blood or the dialysis solution is larger and the diffusion efficiency is excellent compared to its compact volume.
The conventional blood dialyzing apparatus will be described below more in detail in conjunction with the accompanying drawings.
As illustrated in
The blood dialyzing filter 100, as shown in
The blood dialyzing filter 100 configured as illustrated in
As illustrated in
At the point where the blood pressure is higher than the dialysis solution pressure, the water, electrolytes, and the waste materials inside the slashed area shown in
However, in the conventional blood dialyzing apparatus configured as mentioned above, a large volume of blood cannot be dialyzed in a short period of time since the pressure drop of the blood and the dialysis solution are small and large enough pressure differences cannot be achieved. Although a large volume of blood can be dialyzed if the contacting surface of the blood with the dialysis solution is made much larger, the blood dialyzing filter needs to be much longer and a large amount of membrane needs to be used.
The present invention proposes to solve the aforementioned problems and embodiments of the present invention provide a blood dialyzing apparatus formed to efficiently dialyze a large volume of blood without increasing the size of a blood dialyzing filter.
In an exemplary embodiment of the present invention, the blood dialyzing apparatus includes a blood dialyzing filter for dialyzing blood by using a pressure difference between the blood and a dialysis solution, which flow inside the blood dialyzing filter; and a supplying means for supplying the blood and the dialysis solution to the blood dialyzing filter in order to alternately generate a state where a blood pressure is higher than a dialysis solution pressure and a state where the dialysis solution pressure is higher than the blood pressure.
The supplying means may periodically change the blood pressure and the dialysis solution pressure which are supplied to the blood dialyzing filter.
The supplying means is constructed to have a phase difference of 135 degrees or 225 degrees between the blood pulsation waveform and the dialysis solution pulsation waveform.
The blood dialyzing filter is constructed to allow the blood and the dialysis solution to flow in opposite directions.
The blood dialyzing apparatus has advantages of dialyzing a large volume of blood in a short period of time without increasing the size of the blood dialyzing filter and offering simple control of the volume of the dialyzed blood by adjusting the supply pressures of the blood and the dialysis solution.
Embodiments of the blood dialyzing apparatus in accordance with the present invention will be described in detail in conjunction with the accompanying drawings.
When compared to the conventional blood dialyzing apparatus having a drive system of the blood pump 500 and the dialysis solution pump 600 as shown in
In more detail, the blood pressure and the dialysis solution pressure in the blood dialyzing filter 100 are increased and decreased at regular time intervals since the blood dialyzing apparatus of the present invention provides the supply pressure of the blood and the dialysis solution with the increased or decreased pressure at regular cycles, compared to the conventional blood dialyzing apparatus wherein the blood pressure and the dialysis solution pressure in the blood dialyzing filter 100 remain stable regardless of the time since the blood and the dialysis solution are supplied to the blood dialyzing filter 100 with a regular pressure. In this context, the supply means in the blood dialyzing apparatus of the present invention alternately changes the supply pressures of the blood and the dialysis solution in order to alternately increase the blood pressure and the dialysis solution pressure in the blood dialyzing filter 100, so that the blood pressure line (B) and the dialysis solution pressure line (D) have opposite phases.
If the dialysis solution pressure is lowered when the blood pressure is increased, the pressure difference between the blood pressure and the dialysis solution pressure becomes much larger compared to the diagram in
In
When the blood pressure line and the dialysis solution pressure line make a perfect sine curve, the dialyzing efficiency can be maximized to the utmost by increasing the area where the blood pressure is higher than the dialysis solution pressure (slashed area) and the area where the dialysis solution pressure is higher than the blood pressure (cross-striped area) after making the phase difference be 180 degrees. However, if the blood and the dialysis solution are subject to pressure in the actual situation, the pressure line sharply increases when the blood and the dialysis solution are subject to pressure and the pressure line smoothly decreases when the pressure on the blood and the dialysis solution is released. Consequently, a diagram skewed a little in one direction will appear as shown in
As a result, the user can properly adjust the phase difference between the two pressure lines at 180±45 degrees, in other words, in the area from 135 degrees to 225 degrees, according to the shape of the blood pressure line and the dialysis solution pressure line. Now, the reason why the phase difference is limited at 180±45 degrees is that the area where the blood pressure is higher than the dialysis solution pressure (slashed area) and the area where the dialysis solution pressure is higher than the blood pressure (cross-striped area) become smaller and the blood dialyzing efficiency will be only insignificantly increased when the phase difference of the two pressure lines is less than 135 degrees or bigger than 225 degrees.
Furthermore, in the conventional blood dialyzing apparatus, the pressure difference between the blood and the dialysis solution can be created by the natural decrease in the pressure while the blood and the dialysis solution flow inside the blood dialyzing filter 100, and the pressure difference between the blood and the dialysis solution cannot be easily increased, and as a result, there have been many problems associated with adjusting the blood dialyzing volume.
However, in the blood dialyzing apparatus of the present invention, the increasing pressure value of the blood and the dialysis solution flowing into the blood dialyzing filter 100 can be controlled by adjusting the supply means, in other words, the driving power of the blood pump 500 and the dialysis solution pump 600 and the pressure difference between the blood and the dialysis solution can be easily increased/decreased, and as a result, the blood dialyzing volume can be easily controlled.
In the blood and dialysis solution passing through the inside of the blood dialyzing filter 100, a flow pressure drop can occur to a small degree due to the friction against the inside of the blood dialyzing filter 100, and a pressure difference can arise (due to the permissible volume by the supply means) between the blood and the dialysis solution since the flow pressure drop can happen in both the blood and the dialysis solution when the blood and the dialysis solution are flowing in the same direction, for example, both the blood and the dialysis solution are flowing into the top portion and discharged out of the bottom portion of the blood dialyzing filter 100.
The blood dialyzing efficiency can be increased more if pressure differences corresponding to sizes of pressure applied by the supply means and area-specific pressure differences (the pressure difference as shown in
As a result, the blood dialyzing filter 100 can be structured so that the flow direction of the blood and the dialysis solution are in opposite directions.
The supply means for supplying the blood and the dialysis solution to the blood dialyzing filter 100 includes the separately divided blood pump 500 and the dialysis solution pump 600 as shown in
The double acting pump 700, as shown in
The blood sac 710 and the dialysis sac 720 can be made of a flexible material in order to become smaller by the appliance of a pressure force from the outside, so that they supply the blood and the dialysis solution with the larger pressure to the blood dialyzing filter 100 when they are pressed by the pressure member 730, and they can also return to the original condition when the pressure by the pressure member 730 is released.
The pressure member 730 is constructed to turn around the axis located between the blood sac 710 and the dialysis solution sac 720. The pressure member 730 has a protrusive portion formed on one side thereof in order to press the blood sac 710 and the dialysis solution sac 720, and presses the blood sac 710 and the dialysis solution sac 720, respectively, once every time it rotates. As shown in
If the pressure means is constructed with the double acting pump 700 as shown in
In the embodiments of the present invention, the present invention has been described with the exemplary embodiments. In the first case, the pressure means alternately increases the pressures of the blood and the dialysis solution in the blood dialyzing filter 100 by separately constructing the blood pump 500 and the dialysis solution pump 600, and in the second case, the pressures of the blood and the dialysis solution in the blood dialyzing filter 100 can be alternately increased by alternately pressing the blood sac 710 and the dialysis solution sac 720. However, the pressure means is not limited to the structure mentioned in the foregoing embodiments of the present invention and can be modified into any structures capable of alternately increasing the pressures of the blood and the dialysis solution.
While the present invention has been described in connection with the exemplary embodiments, it is not to be limited thereto but will be defined by the appended claims. It is to be understood that those skilled in the art can substitute, change or modify the embodiments in various forms without departing from the scope and spirit of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2008-0044384 | May 2008 | KR | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/KR08/04983 | 8/26/2008 | WO | 00 | 2/28/2011 |
