scholarly journals Modelling of Blood and Dialysate Flow in Hollow-Fiber Hemodialyzers

Author(s):  
Hamid H ◽  
Mohammad JA ◽  
Sobhani FK
Keyword(s):  
1998 ◽  
Vol 22 (10) ◽  
pp. 907-909 ◽  
Author(s):  
Toshiaki Osuga ◽  
Takayuki Obata ◽  
Hiroo Ikehira ◽  
Shuji Tanada ◽  
Yasuhito Sasaki ◽  
...  

1986 ◽  
Vol 9 (3) ◽  
pp. 163-166
Author(s):  
J.H.M. Berden ◽  
J.M.P. Wokke ◽  
R.A.P. Koene

Controlled ultrafiltration (UF) during hemodialysis may prevent dialysis associated hypotension. A prerequisite for controlled ultrafiltration is an accurate measurement of ultrafiltration. Volumetric measurement is the best currently available method for this purpose. In this study we compared in a clinical setting two volumetric ultrafiltration monitors (UFM): one device constructed in our hospital using oval flowmeters (UFM-N) and the other using electromagnetic flow transducers (UFM-G: UFM 10-2, Gambro Lund Sweden). The UF measurements of both UFM's were compared with UF calculated from bedscales weight monitoring and standard scales determinations. During dual needle hemodialysis (n = 8) with a hollow fiber dialyzer the accuracy of the UFM-N was 91% and that of the UFM-G 97%. During dual needle dialysis with a parallel flow dialyzer the UFM-N appeared to be more sensitive for pulsatile changes in the dialysate flow due to the greater compliance of this type of dialyzer. The accuracy of the UFM-N in this setting was 80%, while that of the UFM-G was 87% (n = 11). During single needle dialysis with a parallel flow dialyzer (n = 14) only the UFM-G was tested and it measured UF with an accuracy of 92%. Finally the UFM-G can control UF actively by adjusting the TMP to obtain a given UF rate. The accuracy of the UFM-G in this setting was 94%, and the lineair regression correlation coefficient between planned UF and actually obtained UF was 0.974 (n - 61). In conclusion volumetric monitoring of UF is accurate and reliable, but its accuracy is dependent on the type of dialyzer used. The UFM-G proved to be useful in every dialysis modality tested, while the UFM-N can be used in dual-needle dialysis using hollow fiber dialyzers.


2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Weiping Ding ◽  
Xiaoming Zhou ◽  
Shelly Heimfeld ◽  
Jo-Anna Reems ◽  
Dayong Gao

Hollow fiber modules are commonly used to conveniently and efficiently remove cryoprotective agents (CPAs) from cryopreserved cell suspensions. In this paper, a steady-state model coupling mass transfers across cell and hollow fiber membranes is theoretically developed to evaluate the removal of CPAs from cryopreserved blood using hollow fiber modules. This steady-state model complements the unsteady-state model, which was presented in our previous study. The steady-state model, unlike the unsteady-state model, can be used to evaluate the effect of ultrafiltration flow rates on the clearance of CPAs. The steady-state model is validated by experimental results, and then is compared with the unsteady-state model. Using the steady-state model, the effects of ultrafiltration flow rates, NaCl concentrations in dialysate, blood flow rates and dialysate flow rates on CPA concentration variation and cell volume response are investigated in detail. According to the simulative results, the osmotic damage of red blood cells can easily be reduced by increasing ultrafiltration flow rates, increasing NaCl concentrations in dialysate, increasing blood flow rates, or decreasing dialysate flow rates.


ASAIO Journal ◽  
1977 ◽  
Vol 23 (1) ◽  
pp. 713-715
Author(s):  
S. Nakagawa ◽  
S. Koshikawa ◽  
Y. Joh ◽  
M. Yamazaki

2003 ◽  
Vol 125 (4) ◽  
pp. 481-489 ◽  
Author(s):  
Churn K. Poh ◽  
Peter A. Hardy ◽  
Zhijie Liao ◽  
Zhongping Huang ◽  
William R. Clark ◽  
...  

We used an innovative, nonintrusive MRI technique called the two-dimensional (2D) Phase-Contrast (2DPC) velocity-imaging technique to investigate the effect of flow baffles on the dialysate-side flow distribution in two different hollow-fiber hemodialyzers (A and B); each with flow rates between 200 and 1000 mL/min (3.33×10−6 and 1.67×10−5 m3/s). Our experimental results show that (1) the dialysate-side flow distribution was nonuniform with channeling flow occurred at the peripheral cross section of these hollow-fiber hemodialyzers, and (2) the existing designs of flow baffles failed to promote uniform dialysate-side flow distribution for all flow rates studies.


1995 ◽  
Vol 19 (11) ◽  
pp. 1176-1180 ◽  
Author(s):  
Richard Allen ◽  
Thomas Herbert Frost ◽  
Nicholas Andrew Hoenich

2008 ◽  
Vol 31 (11) ◽  
pp. 944-950 ◽  
Author(s):  
J. C. Kim ◽  
J. H. Kim ◽  
H.-C. Kim ◽  
E. Kang ◽  
K. G. Kim ◽  
...  

Background Uniform dialysate distributions in hollow-fiber hemodialyzers facilitate effective solute removal, and the fiber structure inside hemodialyzers plays a significant role in determining dialysate flow distribution and dialysis efficiency. The authors analyzed the effects of undulated fibers on dialysate flow profiles and hemodialyzer reliability using a perfusion CT technique. Method Using a multi-detector row CT unit, perfusion studies were performed on two different types of hemodialyzers: (A) straight fiber configuration; (B) undulated fiber configuration (wavy-shaped fibers). Deconvolution theory was used for image processing to derive dialysate flows, dialysate volumes, and mean transit time distributions. Three-dimensional perfusion maps for the two types of hemodialyzers were reconstructed using high resolution images and these parameters were compared at hemodialyzer midsections. Results Dialysate maldistributions were observed in both types of hemodialyzer. However, dialysate flow distributions were more uniform in the undulated-fiber hemodialyzer, whereas more complex flow distributions developed in straight-fiber hemodialyzer. Reliability as determined using intraclass correlation coefficients was markedly higher for the hemodialyzer containing undulated fiber (0.968 vs. 0.496 for type A and type B, respectively). Conclusions The undulated-fiber type was found to have more uniform, consistent dialysate flow profiles. It is believed that this type of hemodialyzer will be found helpful for measurement and prescription of the delivered hemodialysis dose due to its better consistency.


ASAIO Journal ◽  
2003 ◽  
Vol 49 (2) ◽  
pp. 193
Author(s):  
S B Eloot ◽  
P De Bondt ◽  
R Dierckx ◽  
P R Verdonck

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