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HEART LUNG MACHINE

HEART LUNG  MACHINE

  • It is an instrument that temporarily takes over the function of the heart and lungs during surgery.
  • It maintains the circulation of blood (blood flow) and the oxygen content of the body (respiration) for the patient while the heart is stopped.
  • The machine is attended to at all times by a specialized technician, called the perfusionist.
APPLICATION

  • It is commonly used in operations requiring the opening of the chambers of the heart to support the circulation during the heart surgery period because of the difficulty of operating on the beating heart.
  • Cardiac valve repair and/or replacement.
  • Repair of heart defects.
  • Transplantation (heart transplantation, lung transplantation, heart–lung transplantation).
 
  • BLOCK DIAGRAM OF HEART LUNG MACHINE:
 
   
  • The major parts of artificial Heart-Lung machine are:
a)         Oxygenator: An oxygenator is a medical device that is capable of exchanging oxygen and carbon dioxide in the blood.
In general the basic types of oxygenators are:

                              1)Bubble Oxygenator
                                                  2)Film Oxygenator
                                                3)Membrane Oxygenator
  

   




















a)         Heat Exchanger: It allows the temperature regulation of the blood by Heat Exchange between blood and media. It control body temperature by heating or cooling blood passing through the perfusion circuit.

                                     b)        Filter: This device filters micro-particles(<40Å) in size, which enters the        machine.
It filters the blood from the artificial heart-lung machine and delivers it to the other parts of the body.
c)         Pump: It permits the blood coming from the reservoir to be driven out from the heat exchanger and supply to the body. Types of Pump used are: 1) Roller Pump, 2) Centrifugal Pump.

d)        Reservoir: Reservoir is the storage device which is responsible for both collection of blood from the venous circulation and distribution of the blood to aortic circulation.

                                    e)         Tubing: They are interconnected by a series of tubes made of silicone    rubber or PVC. It is flexible, compatible with blood, inert, nontoxic, smooth and transparent.
                                     f)          Cannula: A cannula is a tube that can be inserted into the body. A venous cannula removes deoxygenated blood from a patient's body. An arterial cannula is sewn into a patient's body and is used to infuse oxygen-rich blood.

  •  Working:

  •  Consists of a chamber which receives blood from body.
  • Blood is pushed inside the reservoir.
  • Blood is pushed from the reservoir to an oxygenator.
  • Oxygenator removes Carbon dioxide and adds oxygen.
  •   Heat exchanger maintains the blood temperature at body temperature.
  • Pump, then pumps this newly oxygenated blood back to the body.


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