An infusion pump is a device that feeds a liquid medicine, nutrition or fluid into a patient's vein at a set rate. It checks the dose against a built-in drug library, so that a typing mistake does not become an overdose. Nurses set most infusions in millilitres (mL) per hour, or as a dose for each kilogram of the patient's weight.
There are two main kinds. A volumetric pump pushes fluid from a bag through a tube, and is used for larger volumes. A syringe pump pushes the plunger of a syringe slowly, and is used for small, precise doses, often in the ICU and for newborn babies. Both have sensors that stop the pump and sound an alarm if there is air in the line or the tube is blocked.
The drug library is the main safety feature. It is a list, written by the hospital's pharmacists, of every drug used in each ward, with its safe dose limits. A soft limit warns the nurse, who can confirm the dose and continue. A hard limit cannot be overridden. This software is often called dose error reduction software.
Here is a typical case. On a medical ward of a hospital in Indore, a nurse sets up an antibiotic infusion that should run at 50 mL per hour. She types 500 by mistake. The pump checks its library for that drug on that ward. The hard limit is 150 mL per hour, so the pump refuses the rate and asks her to enter it again. She types 50, and the infusion starts. The pump records the refused attempt. Later, the pharmacy can see which mistakes happen most often, and on which wards.
Connected pumps go further. When the pharmacy updates the library, the new version is sent over the hospital Wi-Fi to every pump. The doctor's order can come straight from the hospital EHR. The nurse scans the patient's wristband and the barcode on the drug, and the pump fills in the rate itself, so nothing is typed by hand. This is called auto-programming. The drug bag itself is often prepared by hospital pharmacy automation.
The pump also sends its status to ICU device integration software. It reports its location to a real-time location system (RTLS), so that staff can find a free pump quickly. Biomedical test equipment checks that it really delivers the volume it shows. The syringes and vials it uses come from the makers of drug delivery devices.
Because its software controls doses, an infusion pump is a regulated medical device under the Medical Devices Rules. Each change to its software must be tested and approved before it reaches the wards.