Extracorporeal Artificial Organs
“Extracorporeal artificial organs” are life-supporting techniques that require on-line processing of blood outside the patient’s body. Extracorporeal artificial organs do not belong to the category of infusion pumps for drug delivery, artificial hearts used extracorporeally, eye glasses and contact lenses for vision, and orthotic devices and manipulators operated by neural signals to control motion techniques etc. Rather, they are unique in their own sense of working and principals. In this paper, we will be discussing mainly about the different extracorporeal artificial organ technologies that perform mass-transfer operations to support failing or impaired organ systems. Many methods are involved in this advanced and beneficial process. Thus, these methods are a boon that will surely help mankind combat against the various abnormalities found in their vital as well as non vital organs.
What is a kidney? One of the vital organs, in humans, the kidney occurs in a pair that is located near the vertebral column near the dorsal surface of the body. The left kidney lies a little higher than the right kidney. At least one kidney must function properly for life to be sustained. They are bean-shaped, about 4-inch long and about 21/2 inch wide. Among the various functions, the major functions of the kidney is to separate urea, mineral salt, toxins, maintains the chemical and maintain water balance of the body by removing waste materials from the blood. The kidneys do this by sophisticated mechanisms of filtration and active and passive transport that take place within the nephron. In the glomerulus, the filtration of the blood takes place. The filtrate passes through the nephron’s tubule system to produce urine. There are many kidney related diseases in humans. Some of the most common kidney diseases and abnormalities are renal failure, polycystic kidney disease, nephrosis, lupus nephritis, diabetic nephropathy, rhabdomyolysis, kidney stones, and renal tubular acidosis. Among these, renal failure occurs when the kidneys are damaged to the extent that they can no longer function to detoxify the body. Their failure may be acute or chronic. Acute failure can be treated by watching one’s diet, undergoing a blood pressure check regularly, and also by keeping an eye on the weight of the body.
Below is a figure that shows how hemodialysis and hemodialysis with postfiltration addition of fluid vary according to their working principles.
Figure 1 Comparative operation principles in (a) hemodialysis and (b) hemofiltration with postfiltration addition of fluid
The above figures illustrate the similarities and differences between hemodialysis (A) and hemodialysis with postfiltration addition of fluid (B). They clearly show that the two operations are basically the same but work under different principles.