Implantable pump systems are medical devices used to treat conditions such as ascites. In order to control excessive fluid accumulation in patients’ abdomens, Sequana Medical developed an active implant utilizing maxon EC motors for trouble-free and smooth pump motion.

Ascites is a medical condition in which a large amount of fluid accumulates within the peritoneal cavity. 8/10 cases of ascites are caused by decreased liver function, as occurs with conditions like cirrhosis. However, it can also be caused by reduced myocardial function, kidney diseases, or cancer. Most patients find relief through medication and a tailored diet. However, for thousands of patients a year, this treatment method no longer works. A patient with ascites can accumulate up to two liters of fluid in their abdomen per day. Before the ALFApump System, the only way to remove the fluid was via a medical operation called “tapping.”

maxon brushless motors for medical technology play a crucial role in this device, enabling it to function as intended and provide a higher quality of life to patients.

The ALFApump System

The ALFApump system is a medical implant designed by Swiss medical technology specialist, Sequana Medical, to ensure patients with ascites can lead an uncomplicated life. This device monitors fluid accumulation within the abdomen and when pre-set levels are reached, the device pumps fluid into the bladder of the patient where it is excreted with the urine.

The device consists of a three-part system with two catheters, one to the peritoneum and one to the bladder. The external SmartCharger with charging station is a mobile charging and communication unit that charges the battery of the ALFAimplant and enables communication with the device. The lithium ion battery allows for autonomous operation for several days. Due to the energy consumption of the pump (per day about 0.9 liters is pumped out, on average), the battery has to be regularly charged, but can be done wirelessly through the skin of the patient.

Demanding Conditions

The ALFApump implant is inserted between the subcutaneous fat layer and the peritoneum and is made of PEEK (polyether ether ketone), a biocompatible plastic. The human body is one of the most demanding environments for any device and, as such, poses unique complications and challenges. This device needed to use special motors and appropriately adapted electronics as no hermetically sealed encapsulation is possible when using a plastic. The materials of the device also must withstand permanent moisture exposure and an increased salt concentration. Finally, fluid in the peritoneal cavity contains high quantities of fibrin and protein from blood plasma. This fluid can easily clot and cause the pump to not function properly. The avoid this, the pump performs a short movement without volume transport at regular intervals.

High Precision in Medical Technology – EC Motors for Implantable Pumps

The maxon EC motors for implantable pumps, specifically the EC 13 model, drive the pump gear of the ALFApump. This motor is equipped with Hall sensors that provide position feedback and are used to maintain stable operation even at low speeds and high load torques. The motor is sterilizable and has a special stator coating with a shaft that is also biocompatible. The maxon EC 13 is perfectly suited for medical applications due to its low-noise and low-vibration running properties and low-heat emission.

Electromate supplies EC 13 motors from maxon like those used in this medical application. For more information, contact us today.