Customizable Piston Pumps: Key to Effective Shock Wave Therapy
KNF's NPK swing piston pumps enable medical device manufacturers to precisely control pressure in compact shock wave therapy devices, improving the effectiveness of treatments for conditions such as musculoskeletal disorders using shock wave stimulation.

Modern extracorporeal shock wave therapy (ESWT) devices precisely generate therapeutic pressure waves, effectively treating a wide range of medical conditions. At the heart of this technology, KNF's NPK piston pumps provide the consistent pressure generation and precise control required by medical device manufacturers.
High-Pressure Pumps Power Advanced Shock Wave Therapy
Shock wave therapy is an innovative medical treatment that uses specialized equipment to generate either radial or focused shock waves. Used to treat a wide range of musculoskeletal conditions such as tendinopathies, muscle pain, osteoarthritis, delayed fracture healing, and skin conditions such as lymphedema and non-healing wounds, it relies on a sophisticated device consisting of a base unit and attached handpiece. A compressor inside the device rapidly accelerates a projectile in the handpiece, causing it to repeatedly strike a metal plate and transmit these impulses through the treatment head.

The shock wave begins with a period of positive pressure, which creates shear stress in the tissue. As the shock waves travel through the body's tissues, they are gradually absorbed. The subsequent negative pressure phase creates cavitation bubbles that collapse at high speed. This plays a critical role in extracorporeal shock wave therapy by enhancing therapeutic effects such as promoting tissue regeneration and improving blood circulation. The specific effects can vary depending on the condition being treated, but may include pain relief, improved circulation, and stimulation of the body's natural healing processes. Orthopedic applications benefit from precise wave focusing to treat musculoskeletal disorders, while dermatological treatments use carefully regulated pressure levels to promote wound healing and tissue regeneration.
KNF NPK 09: Reliable Air Compression for Effective Shock Wave Therapy
The NPK 09 swing piston pump is a key component in shock wave therapy devices. Located inside the unit, it acts as the air compressor that reliably accelerates the projectile in the treatment handpiece. As with all KNF diaphragm pumps, customizability is key and makes piston pumps suitable for a wide range of medical applications. For quieter operation and to reduce heat generation under pressure, the NPK 09 can also be customized to feature two pump heads that then operate at a correspondingly slower speed. This is especially beneficial for applications such as musculoskeletal treatment, where the reduced speed of the two installed pump heads allows the pump, and therefore the ESWT device, to run cooler and quieter without compromising performance.

With flow rates of up to 24 l/min in double-head configuration and pressures of up to 7 bar, the NPK 09 provides the power needed for effective therapy. The piston design provides a consistent pressure curve while operating with minimal vibration, allowing for precise therapeutic application. In addition, its compact design provides high power density in a comparatively small form factor, which is particularly beneficial in medical and non-invasive therapy applications that require increasingly portable, compact and efficient devices.
Customizable for Applications Across Medical Fields
The unique characteristics of KNF's NPK swing piston pumps offer many benefits to both medical professionals and patients. As the market moves toward smaller, more portable devices, KNF's customizable pumps are at the forefront of this trend. Their customizability allows them to be used in a wide range of applications, making them the ideal choice for medical device manufacturers looking to innovate and improve patient care.