Artificial livers

Research teams are working to develop a first artificial liver.

Working on the principle of externally filtering chronically ill liver patients' blood through layers of liver cells, the artificial liver would be used as an alternative to transplants for some patients, or as a way of keeping others alive while they await a suitable donor organ.

Blood is pumped to and from the artificial liver:

1. Plasma Separator
2. Artificial Liver
3. Additional Pump
4. Red Blood Cells

Experimenting with liver cells from pigs, a team of researchers from Edinburgh Royal Infirmary and Glasgow's Strathclyde University are working on an artificial liver which works in the same kind of way as dialysis machines are employed in cleaning the blood of patients with kidney disease.

Meanwhile a team from the Queen Elizabeth Hospital in Birmingham are experimenting with artificial livers grown from pieces of human liver, left over after organ transplants. The intention is to grow livers weighing 1lb or more from off-cuts of human livers weighing just 1oz to 2oz.

The device will receive separated plasma from the patient via a tube in the groin. A fine network of hundreds of tiny, permeable plastic tubes will force the plasma to mix with the cells of the artificial liver, toxins removed and any necessary compounds converted. A second permeable network of tubes will receive the processed plasma and return it to the body.

1. Blood plasma flows into the artificial liver under pressure and spreads into a network of fine permeable tubes
2. Tube brings oxygen into the system and removes carbon dioxide
3. Plasma passes through walls of tubes. Toxins are removed, new proteins created and other substances broken down into products needed by the body
4. Processed plasma flows into lower pressure tubes to be remixed with red cells and returned to the patient