In automated peritoneal dialysis, the cycler is the machine that automatically fills and drains your belly. You can program the cycler to give you different amounts of dialysis solution at different times. Most cyclers include the following:

• Solution supply: At the beginning of the session, you connect bags of dialysis solution to tubing that feeds the cycler. Most systems have a separate tube for the last bag because this solution may have a higher dextrose or icodextrin content so that it can work for a daylong dwell time.

• Pump: The pump sends the solution from the supply bags to a heater bag before it enters your body. The pump also sends the solution to the disposal container or drain line after use. However, the pump does not move the solution into and out of your belly; gravity performs that job.

• Heater bag: Before the solution enters your belly, the cycler warms a measured dose to body temperature. Once the solution is the right temperature and the previous exchange drains, the cycler releases a clamp to let the warmed solution flow into your belly.

• Fluid meter: The cycler’s timer releases a clamp to let the pump send the used dialysis solution into a disposal container or drain line. A fluid meter in the cycler measures and records how much solution the cycler removes. Some cyclers compare the amount that was put in with the amount that drains out. This comparison lets you and your doctor know if the treatment is removing enough fluid from your body.

• Disposal container or drain line: After measuring the used solution, the cycler pumps the used solution to a disposal container that you can throw away. With some systems, you can just string a long drain line from the cycler to a toilet or bathtub.

• Alarms: Sensors will trigger an alarm and shut off the cycler if a problem occurs.