1. DIALYSERS

2. DEFINITION: Is a part in the artificial kidney system
the treatment actually takes place
Blood is freed from waste products
Need:
Removal of waste product from plasma
Regulation of the composition of blood plasma
To retain the normal pH of the blood

3. Process: 3 process: Diffusion Osmosis ultrafiltration
The rate of clearance of waste products (64 ml/minute) from the blood depend upon the rate of blood flow(200 ml/minute).

4. TYPES: Parallel flow dialyzers Coil hemodialyzer
Hollow fibre Haemodialyzer

5. Parallel flow dialyzers:
No need for blood pump
Uses arterial blood pressure
3 polypropylene boards with dialyzing membranes laid between them
Held firmly and fastened by bolds at the sides
Rubber gasket: avoids leakage
Longitudinal grooves are also made (increased surface area)

6. Contd. Not disposable ( needs technical skills) Cleaned and re-built
Avoids bacterial infections
higher efficiency

7. Contd.

8. Coil hemodialyzer:
Tubular membrane placed between flexible support wrapped around a rigid cylindrical core
Membrane: cellophane (20-30) micron or cuprophane (18-75)micron
Channels for blood (1,2,4)
Width of channel (38-100)mm

9. Hollow fibre Haemodialyzer
Most commonly used
10,000 hollow de-acetylated cellulose di-acetate capillaries
Covered by plastic cylinder (18 cm in length, 7cm in diameter)
Dialyzing area is 9000 cm2 / unit
130ml of blood

10. Contd.

11. contd: Advantages: Drawbacks: Expensive
Disposable (sterilization is eliminated)
Reduction in infection risk
Reduced operator set-up time
Drawbacks:
Expensive

12. Performance analysis:
Clearance:
Overall performance
Part of the total blood flow through the dialyser which is completely cleared of solute
clearance=
blood flow rate / A+Bx blood flow rate
A and B are constants

13. Contd.
Dialysance curve:

14. Contd.
Residual blood flow:

15. Contd. Performance capacity: = A/ RS A = surface area
Rs =mass transfer resistance
Priming volume:
Volume of blood within the dialyzer
75 ml to 200 ml

16. Contd. Pyrogenicity: Pyrogen reaction KIIL dialyser Leakage rate:
Blood-to-dialysis fluid leak – 3%

17. Dialyzer:

18. Dialyzer:

19. Heart lung machine Artificial heart-lung function
During open heart surgery
To maintain circulation and gas exchange
Extra corporeal circulation
Pumping and oxygenation

20. Heart lung machine

21. Systole/ diastole: Pressure: 130/75 mm of Hg in aorta
130/5 mm of Hg in left ventricla
9/5 mm of Hg in left atrium
25/0 mm of Hg in right ventricle
3/0 mm of Hg in right atrium
25/12 mm of Hg in pulmonary artery

22. Heart lung machine – a model

23. Process: Filter : to avoid air bubble
Ventriclular fibrillation : breakdown of red blood cells
Blood is rewarmed

24. Process:

25. Blood pumps: Two types: Pulsatile pump
2 chambers : inner chamber and outer chamber
Non-pulsatile pump
Roller is present
Time extended: may produce breakdown of RBC

26. Characteristics of an ideal blood pump:
Calibration should be perfect
Automatically and manually
Rate : 6 l/minute
Not damages the blood cells
Unwanted mechanical stress should not be there
Pump must be cleaned easily
Smooth parts: avoids clot

27. Oxygenators: Function of lungs Artificial lungs
5 litres of blood per minute

28. Types: Bubble Membrane Liquid-liquid Film Rotating disc film Foam
Blood film
screen

29. Bubble oxygenator:
Oxygen is bubbled through the blood and the blood flows through the slanting path
Beads, sponges, meshes with anti foaming agent(silicon)
Bubbles are broken since silicon reduces the surface tension

30. Membrane oxygenator: O2 travels in the opposite direction
Effective oxygenation
Micro porous polyethylene

31. Liquid-liquid oxygenator:
Blood and liquid with dissolved oxygen are travelling in the opposite direction
Gaseous exchange takes place

32. Film oxygenator: Rotating disc type: Horizontal disc type 120 rpm
Film is formed and then oxygenated and removed