Artificial Heart From Berlin Heart Gives Life

Ventricular assist device with integrated KNF pumps bridges the waiting time for a suitable donor organ

There is a shortage of organ donors worldwide: in Germany alone, almost 1,000 people are currently waiting for a donor heart, but only about one third of the patients per year are lucky enough to receive a suitable donor organ. The majority of patients have to wait. However, this means precious time, which very few of them have. This waiting time can only be bridged with a ventricular assist device. The German company Berlin Heart GmbH with their EXCOR® Pediatric system is the only supplier worldwide to have developed a ventricular assist device, which has been approved for newborns. In the following article, you can find out how highly specialized KNF diaphragm pumps in the associated drive unit help to successfully simulate a heartbeat.

KNF diaphragm pumps play a key role in ventricular assist devices

If a patient suffers from heart failure, urgent action must be taken to relieve the stress on the heart while waiting for a donor organ. For this purpose, a ventricular assist device (VAD) can be used temporarily. Throughout the world, the EXCOR® Pediatric system from Berlin Heart is unique among these applications. This mechanical blood pump is located outside the body and is connected to the heart and vessels via cannulas. EXCOR® Pediatric consists of one or two blood pumps, cannulas and a drive unit.


The blood pump is driven electropneumatically: In order to pump the blood, it relies on the movement of air to actuate a membrane, thereby generating a blood flow. This required air pressure is generated by a drive unit. Three interconnected KNF diaphragm pumps at the heart of the Ikus stationary drive unit tirelessly perform this duty.

A simulated heartbeat requires the reliable continuous operation of blood pump and components

Due to the long waiting times for donor organs, EXCOR® with all its components is designed for long-term use. Like the artificial heart from Berlin Heart, the KNF diaphragm pumps used in the Ikus drive unit also run continuously. They provide both pressure and vacuum, which in turn drive the blood pumps of the Berlin Heart EXCOR® systems to simulate the patient’s heartbeat. This is a highly sensitive and critical process. That is why the highest level of safety is a top priority in the technical implementation: In addition to the two active KNF pumps, a third one is installed as a backup that, in extreme cases, can take over the functions of the other two KNF pumps for a limited time.

The continuous and long-term use entails special requirements and safety precautions. The compressors are replaced every 10 years as part of the maintenance schedule of the Ikus drive unit. This is done purely as a preventive measure to exclude any possible hazard to the patient due to a potential failure of aging components. A long service life was not the only criteria that KNF diaphragm pumps had to meet.

Successful implementation of customer-specific requirements thanks to the KNF modular system

The high demands on the application were accompanied by clear specifications for the development of suitable, reliable diaphragm pumps. As a result, Berlin Heart provided clear specifications for the implementation of the EXCOR® diaphragm pumps: The pumps were to be efficient and low-maintenance, and the KNF diaphragm vacuum pumps provide all of this. They also impressed the developers at Berlin Heart with their quiet and low-vibration performance during operation. Using the KNF modular system, Berlin Heart and the KNF development team worked together to optimize the parameters until the N 023.1.2 series model was ideally adapted to meet customer’s specific requirements. Among other things, specially adapted ribbed plates and a special silicon wiring had to be used.


However, not only the manufacturer, but also the TÜV and international certification bodies require that the strictest standards must be met. By carefully fine-tuning all components to work with each other, Berlin Heart was able to obtain premarket approval (PMA) for its EXCOR® Pediatric product for the US market.

Successful use saves thousands of lives

The result is also convincing in practice: KNF pumps work reliably and quietly around the clock. The ventricular assist device from Berlin Heart supports around 180 children every year and has already saved more than 2,500 lives.


Our decades of expertise gained in successful cooperation with leading medical device manufacturers allow us to understand the high demands placed on their applications and the components installed in them. We are also happy to answer your questions and help you implement your specific medical application. Contact a KNF expert regarding your project.

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