Computational Evaluation of Dialysis Fluid Flow in Dialyzers With Variously Designed Jackets

Yamamoto, Kenichiro; Matsuda, Masato; Hirano, Ayumi; Takizawa, Natsuo; Iwashima, Shigeto; Yakushiji, Taiji; Fukuda, Makoto; Miyasaka, Takehiro; Sakai, Kiyotaka

doi:10.1111/j.1525-1594.2009.00753.x

Cited by 23 publications

(14 citation statements)

References 7 publications

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“…17 Whereas blood enters and leaves the dialyzer through the header, dialysate enters and leaves at ports in the main body of the dialyzer. 19 As such, a mechanical baffle is placed at both the dialysate entry and exit points to direct the incoming and outflowing dialysate ( Figure 1).…”

Section: Dialysate Flowmentioning

confidence: 99%

How can dialyzer designs improve solute clearances for hemodialysis patients?

Davenport

2014

Hemodialysis International

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Improvements in dialyzer technology and design have led to a reduction in both dialyzer size and cost, but also dialysis session treatment times as hemodialysis has evolved from using the cellulosic coiled drum dialyzer to the flat plate Kiil, to the current generation of hollow fiber capillary dialyzers. Newer manufacturing techniques have led to smoother, more consistent pore sizes and larger pore sizes increasing middle molecule clearances with the development of higher permeability dialyzers, and changing polymer composition to increase hydraulic permeability. Modifications to the dialyzer casing and capillary fibers can also increase the efficiency of solute clearances. Although very efficient in removing the smaller water-soluble azotemic toxins, the current generation of dialyzers is not so effective in removing other azotemic toxins, including protein-bound solutes, necessitating the development of newer designs.

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Section: Dialysate Flowmentioning

confidence: 99%

How can dialyzer designs improve solute clearances for hemodialysis patients?

Davenport

2014

Hemodialysis International

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“…The flow of dialysis fluid and blood in the test dialyzers was determined by evaluating the residence-time distribution of red Indian ink used as a tracer, by using the pulse-response method [1,12,18]. The flow of dialysis fluid and blood can then be analyzed using 2 alternative solutions with viscosities and densities equal to those of dialysis fluid and blood.…”

Section: Test Dialyzersmentioning

confidence: 99%

“…It is inappropriate to have a comparative experimental discussion on the housing structure of commercially available dialyzers only because the housing structures of commercially available dialyzers vary in more than 2 aspects. Simulation analysis is an appropriate method for determining the optimum flow in the dialyzers to cut costs [12]. Technical visualization is also necessary because it is otherwise difficult to evaluate the adequacy of the simulation analysis.…”

Section: Introductionmentioning

confidence: 99%

Experimental evaluation of flow and dialysis performance of hollow-fiber dialyzers with different packing densities

et al. 2011

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The dialyzer housing structure should be designed in such a way that high dialysis performance is achieved. To achieve high dialysis performance, the flow of the dialysis fluid and blood should be uniform, without channeling and dead spaces. The objective of this study was to evaluate the effect of fiber packing density on the flow of dialysis fluid and blood, and on the dialysis performance of a hollow-fiber dialyzer at defined flow rates for blood (Q (B) = 200 mL/min), dialysis fluid (Q (D) = 500 mL/min), and filtrate (Q (F) = 0 mL/min). We measured Q (D), Q (B), and solute clearance for 3 test dialyzers with dialyzer housing different diameters. To evaluate the flow of dialysis fluid and blood, we measured the residence time of the dialysis fluid and blood in the test dialyzers by use of the pulse-response method. We also measured the clearances of urea, creatinine, vitamin B(12), and lysozyme to evaluate the dialysis performance of the test dialyzers. At packing densities ranging from 48 to 67%, higher packing densities and lower housing diameters of the dialyzer resulted in higher dialysis performance because the dialysis fluid and blood entered the hollow-fiber bundle smoothly and, hence, increased contact area between the dialysis fluid and the blood led to better dialysis performance.

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“…New design elements including a jacket with a full baf e and short taper structure, and a new wave design for the hollow ber membranes have been introduced in new dialyzers to achieve a more even dialysis ow and better solute removal performance. The relationship between dialysis uid ow and the above-mentioned new design concepts can be veri ed [4,5].…”

Section: Introductionmentioning

confidence: 99%

“…Hence, the recently developed dialyzers are based on new design concepts incorporating jackets or hollow bers that provide an evenly distributed ow [3][4][5]. We previously reported the results of quantitative analyses of the dialysis uid ow and solute removal performance using mass transfer correlation equations [4].…”

Section: Introductionmentioning

confidence: 99%

Identical Dependence of Dialysate-side Mass Transfer Coefficient on Reynolds Number Using Dimensionless Correlation Based on the Mass Transfer Model in Newly Developed Dialyzers and a Downsized Dialyzer

Fukuda

Namekawa

Sakai

2016

ABE

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The dialysis uid ow and solute removal performance of newly developed dialyzers and a downsized dialyzer were evaluated using a dimensionless correlation equation related to the mass transfer coef cient of the dialysate-side lm in a mass transfer model, which was used in quantitative analyses in our previous study. The solute removal performance is greatly dependent on the dialysis uid ow for low molecular weight solutes. Hence, the recently developed dialyzers are based on new design concepts incorporating jackets or hollow bers that provide an evenly distributed ow. The new dialyzers tested were APS-15SA, PES-15Sαeco, PN-140S, and NV-15U. APS-15DSplus was used as a downsized version of the APS-15SA. The dialysate-side equivalent diameter d e is smaller in the APS-15DSplus than in the APS-15SA, while the other design speci cations are identical for these two devices. We measured vitamin B 12 clearance with the dialyzers operated at a blood-side ow rate Q B = 200 mL/min, dialysate-side ow rates Q D = 300-700 mL/min, and a net ltration rate Q F = 0 mL/min. We then calculated the overall mass transfer coef cient. Using this value, we derived the dimensionless correlation of the Sherwood number (Sh), which includes the dialysate-side lm mass transfer coef cient (k D ) and Reynolds number (Re D ). The exponent of Re D was approximately 0.5 for all the dialyzers. The newly developed dialyzers have various design features for improving dialysis uid ow. Unlike previous devices, the various new designs result in a convergence of performance. A comparison of APS-15SA and the downsized APS-15DSplus showed similar dependence of k D on Re D . This nding is novel and is attributed to the similarity in the relationship between dialysate-side uid ow and dialysate-side lm mass transfer in the two devices. In both dialyzers, the jacket has a full baf e and short taper structure, and the wave design of the hollow ber membranes is identical. However, d e was smaller in APS-15DSplus. Thus, analogous design concept employing the dimensionless correlation can be adopted for downsizing a device.

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Computational Evaluation of Dialysis Fluid Flow in Dialyzers With Variously Designed Jackets

Cited by 23 publications

References 7 publications

How can dialyzer designs improve solute clearances for hemodialysis patients?

How can dialyzer designs improve solute clearances for hemodialysis patients?

Experimental evaluation of flow and dialysis performance of hollow-fiber dialyzers with different packing densities

Identical Dependence of Dialysate-side Mass Transfer Coefficient on Reynolds Number Using Dimensionless Correlation Based on the Mass Transfer Model in Newly Developed Dialyzers and a Downsized Dialyzer

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