This document provides an overview of roller pumps used for cardiopulmonary bypass. It discusses the ideal characteristics of blood pumps, the history and evolution of roller pump designs, how roller pumps work by compressing tubing between rollers and a backing plate, different types of tubing materials used, principles of operation and flow determinants, occlusion adjustment, advantages and disadvantages, and alternative pump designs like nonocclusive roller pumps.

1. BY
DR.VIJAYANAND PALANISAMY
ROLLER PUMP

2.  Ideal characteristics of blood pump
 Types of Blood Pumps
 Roller pump
 History
 Structure – tubing
 Types of roller pump
 Principles of operation & Flow determinants
 Adjustment of occlusion
 Advantages / disadvantages
 Various types in use
 Nonocclusive roller pump

3.  move large volumes of blood (up to 7 L/min)
against significant pressures (perhaps up to 500
mm Hg proximal to the arterial cannula)
 pump should minimize flow velocity so that
damage to the blood is minimized
 should not damage the blood cells and should
not activate either the inflammatory or
coagulation cascades

4.  Design should be simple and free from dead
spaces and recesses to avoid stagnation and
turbulence.
 Calibration of the pump should be easy,
reliable, and reproducible.
 The pump should be automatically controlled
and operated for routine use,
 designed for possible manual operation in case
of power failure

5.  Kinetic Pumps
 Centrifugal pumps
 Positive Displacement Pumps:
 Rotary Pumps

6.  This type of pump moves blood forward by
displacing the liquid progressively, from the
suction, to the discharge opening of the unit

7.  Use rollers along flexible tubing to provide the
pumping stroke and give direction to the flow
 This type of positive displacement pump can be
set to provide pulsatile or non-pulsatile
(laminar) flow.

8.  first patented in
1855 by Porter and
Bradley

9.  In 1887, Allen patented a pump designed for
blood transfusion
 In 1934, DeBakey et al. made a modification to
the Porter-Bradley infusion pump to prevent
creepage of the latex rubber tubing during
blood transfusion. added a flange to the outer
circumference of the tubing, which was then
clamped into the housing
 1959, Melrose proposed a more advanced
design, in which the roller ran along the tubing
held in place by a grooved backplate

11. • Roller pumps contain a length of tubing located inside a
curved raceway
• This raceway is placed at the travel perimeter of rollers
mounted on the ends of rotating arms
• These arms are arranged in such a manner that one
roller is compressing the tubing at all times.

12. Three basic materials currently used for tubing:
• silicone rubber,
• latex rubber, and
• polyvinyl chloride (PVC)- most widely used (durability
and acceptable hemolysis rates)

13. • Hemolysis
Latex rubber > PVC > silicone rubber
• PVC tubing stiffens during hypothermic CPB and tends to
induce spallation,. Silicone rubber > PVC

15. • Because one of the two rollers is always compressing the
tubing, the double-roller pump generates a relatively
nonpulsatile flow.
• Debate over the advantages and disadvantages of non-
pulsatile or pulsatile perfusion during cardiopulmonary
bypass still continues

16.  roller pump causes blood to flow by compressing
plastic tubing between the roller and the
horseshoe-shaped backing plate as the roller turns
in the raceway
 Flow from a systemic roller pump is linear with
rpm
 The stroke volume, or output in milliliters per
rpm, of a roller pump can vary slightly depending
on tubing material, elasticity, or temperature but
generally ranges from 12.7 (1/4-inch ID tubing) to
41.9 mL (1/2-inch) when using a 6-inch dual roller
pump

18. A. pump head and tubing diameter,
B. roller RPM, and
C. length of tubing in contact with the rollers
 Roller pumps are relatively independent of
circuit resistance and hydrostatic pressure

19.  Forward or retrograde flow of blood can be
achieved by altering the direction of pump
head rotation; thus roller pumps are commonly
used as the primary arterial flow pump as well
as for suction of blood from the heart and
mediastinal cavity during CPB to salvage blood
, to deliver cardioplegic solution

20.  Roller pumps require occlusion adjustment for
optimum function and avoidance of hemolysis
and activation of leukocytes and platelets
 Occlusion - separation between the rollers and
the backing plate (or raceway)
 Total occlusion is not used
 Excessive compression aggravates hemolysis
and tubing wear; too little occlusion may also
aggravate hemolysis

21.  holding the distal systemic flow line, which is
primed with clear fluid, vertically so that the
top of the fluid column is 30 to 40 inches above
the pump. The occlusion is adjusted until the
fluid level falls at a rate of 1 inch/min.

22. ALTERNATIVE
METHODS
• (i) clamping the outlet tubing from the roller pump
and slowly advancing the rollers to pressurize fluid
within the line, stopping the pump, and then
adjusting the occlusion until a slow decline in
pressure monitored distal to the pump head is
observed; and (ii) clamping the distal tubing and
adjusting the occlusion while slowly rotating the
pump head so as to maintain pressure in the tubing
greater than that anticipated during CPB (e.g., 300
to 400 mm Hg); this method requires a valved shunt
between the outlet and inlet tubing of the pump

23.  For suction or vent pumps, the occlusion is set
by clamping the tubing on the inlet side of the
roller pump and gradually occluding the
rotating rollers until tubing within the pump
head just collapses.
 When occlusion is properly set, the pump flow
rate does not significantly decrease as the
afterload (arterial pressure) increases

24.  Hard:
 •Descent rate< 0-1 cm/min
 5 RPM against occlusion = > 350 mmHg
 Medium:
 Descent rate 2-3 cm/min
 5 RPM against occlusion = 250 - 350 mmHg
 Light:
 Descent rate 4-10 cm/min
 5 RPM against occlusion = 200 - 250 mmHg

25.  Out put is accurate because it is not dependent of the
circuits resistance (including the patients resistance)
 Occlusive, therefore if power goes out the arterial line
won’t act as a venous line

26.  malocclusion (over- or underocclusion),
 miscalibration,
 fracture of the tubing,
 "runaway" pumping ,
 loss of power,
 spallation, and
 the capacity to pump air(Cavitation)
 High RPM and fully occlusive settings tend to
promote blood damage

27.  which refers to the release of plastic
microparticles from the inner wall of tubing as
a result of roller pump compression

28.  sudden occlusion of the inflow to the pump, as a result of low
circulating volume or venous cannula obstruction, can result in
“cavitation,” the formation and collapse of gas bubbles due to the
creation of pockets of low pressure by precipitous change in
mechanical forces.
 pressure-regulated shunt between the outflow and inflow lines of
the roller pump
 However, this usually does not occur because the tubing that
enters the roller pump is short and is connected directly to a
reservoir that contains enough blood to preclude development of
significant negative pressure

29.  Rawn et al. found no difference in hemolysis
between a roller pump with a standard set
occlusion and a centrifugal pump at a 4.5-
L/min blood flow rate with an afterload of 250
mm Hg. When the occlusion is opened such
that pumping at 5 rpm against occluded tubing
maintains a pressure of 150 to 225 mm Hg, the
roller pump induces less hemolysis than a
centrifugal pump

30. Advantages
 Power leads accessible from front
 Easy to operate alarm status
 Delayed reversing
 Clutchable hand cranking
 Easy to wheel
 Can hand crank with lids closed
 Alarm status turns off both main
& cardioplegia
Sarns 8000
Disadvantages
• Hinge occlusion mechanism - not as
secure as COBE
• Bulky
• Tilted operating panels (if spill)
• Individual collars

31.  Advantages
 Compact design
 Easy to operate alarm status
 Difficult to wheel
 Disadvantages
 Difficult to access power outlets
 Computer configuration - difficult to control
 Non clutchable cranking
 Lids must be open to crank
COBE

32. Advantages
 Rotating head turrets
Disadvantages
 Difficult to control alarms
 Flat control surface - poor spill control; items
could be dropped directly on & damage
 Opaque pump covers - difficult to see
 Preloading tubing line inserts (had to be
initially removed)
Stockert

33.  Advantages
 Fully computerised - downloads everything
 Fully automated everything
 Runs from transformer- not so subject to
current surges [converts AC to DC]
 Universal collars
Disadvantages
 More complex to operate?
 Unique operating procedures – non
intuited
 During failures - requires codes to be
switched into manual override
 Non modular design - if base fails (or
computer system) the whole system goes
down
Gambro/Jostra

34. Flat compliant tubing is fitted under tension over the
rollers.
Nonocclusive roller pumps require positive pressure at
the inlet to fill the tubing as the rollers turn.
Macroair emboli are unlikely.
Nonocclusive roller pumps require use of an in-line
flowmeter
Nonocclusiverollerpumps

35.  Metaplus pump is a new type of
blood pump that appears to
incorporate some advantages of a
centrifugal pump while minimizing
some disadvantages of a
conventional roller pump
 This pump will not drain the
venous reservoir, will not create
negative pressure and cavitation,
will not overpressurize, and will
not allow retrograde flow
Metaplus pump

36.  Forward fluid flow is accomplished
by a passive-filling tapered
pumping chamber fabricated of
two sheets of flat polyurethane
tubing bonded at the edges
 pump chamber segment is
stretched under tension over three
rollers.
 no backing plate against which the
tubing can be compressed with
rollers.
 The rollers are mounted on a rotor
that spins to impart a peristaltic
action on the fluid within the
pump chamber
 priming volume is 120 mL

38. 1. LeGallois JJC. Experiments on the Principle of
Life (tr. by NC and JC Nancrede). Philadelphia,
M. Thomas, 1813.
2. von Frey M, Gruber M. Untersuchungen uber den
stoffwechsel isolierter organe. Ein respirationsapparat
fur isolierte organe. Arch f Physiol (Leipz.)
1885; 9:519.
3. Gibbon JH. Artificial maintenance of circulation
during experimental occlusion of pulmonary
artery. Arch Surg 1937; 34:1105.
4. Gibbon JH. Application of a mechanical heart
and lung apparatus to cardiac surgery. Minn Med
1954; 37:171.
5. Andreasen AT, Watson F. Experimental cardiovascular
surgery. Brit J Surg 1952; 39:548.
6. Andreasen AT, Watson F. Experimental cardiovascular
surgery: Discussion of results so far
obtained and report on experiments concerning
donor circulation. Brit J Surg 1953; 41:195.
7. Lillehei CW. Controlled cross-circulation for
direct-vision intracardiac surgery: Correction of
ventricular septal defects, atrioventricularis
communis and tetralogy of Fallot. Postgrad Med
1955; 17:388.
8. Lillehei CW, Cohen M, Warden HE, Read RC,
Aust JB, DeWall RA, Varco RL. Direct vision
intracardiac surgical correction of tetralogy of
Fallot, pentalogy of Fallot and pulmonary atresia
defects. Report of first ten cases. Ann Surg 1955;
142:418.
9. Dale HH, Schuster EA. A double perfusion
pump. J Physiol (London) 1928; 64:356.
10. Galletti PM, Brecher GA. Heart-Lung Bypass:
Principles and Techniques of Extracorporeal
Circulation. NewYork, Grune & Stratton, 1962.
11. Beck A. Zur Technik der bluttransfusion. Klin
Wschr 1924; 2:1,999.
12. Issekutz BV. Beitrage zur wirkung des insulins.
I. Insulin-Adrenalin Antagonismus. Biochem
Ztschr 1927; 183:283.
13. Bayliss WM, Muller EA. A simple, high speed
rotary pump. J Scient Instrum 1928; 5:278.
REFERENCE

39. THANK YOU