Therapy sources and focal zones designed for individual indications


The use of focused shockwaves has become an established procedure to treat many indications. As the number of indications for shockwave treatments and the ESWT therapy options have increased, the requirements for the focal zones of shockwaves in terms of their penetration depth, intensity, shape and volume have also increased significantly. These days, the idea that one focal zone fits all applications is out of date. A modern, innovative shockwave system must be able to adapt to the structure of the respective target tissue. In addition to designing broad-spectrum therapy sources, Richard Wolf GmbH and ELvation Medical GmbH have made it their mission to develop the right therapy sources and focal zones for many different indications to meet the need for successful optimized treatments. All therapy sources shown on this page can be used with the PiezoWave² system. Expanding your therapeutic options by upgrading from a universal therapy source to new and specialized therapeutic procedures sometime in the future is always possible.


Focal sizes and their standards …

Focal size, impact zone, -6dB zone, 5 megapascal (MPa) zone, central penetration depth, maximum/distal penetration depth, energy flow density … the terms are confusing and are often used randomly in advertising. It is important to be aware that standards exist to describe focal zones, as discussed in the simplified explanations given below:

The -6dB zone which is often used to compare measurements and studies refers to that area of the focal zone where pressure amplitudes of at least 50% of the maximum value generated at the central point of the focus are achieved. According to current knowledge, however, this figure does not provide any information about the therapeutic impact zone of the shockwave treatment. Based on the assumption that a pressure amplitude of at least 5MPa is necessary in conventional ESWT applications to achieve a therapeutic effect on tissue, the 5MPa zone is increasingly considered to be the therapeutic impact zone. The 5MPa zone is defined as the focal area in an acoustic field where the pressure amplitude = 5MPa.

The reported maximum penetration depth refers to the above-described acoustic fields. The central maximum penetration depth refers to the distance between the skin surface and the point of maximum acoustic pressure when using a gel pad which allows the greatest penetration depth. The maximum penetration depth in the -6dB zone and 5MPa zone refers to the distance between the skin surface and the distal end of the focal zone, again when a using gel pad which allows the greatest penetration depth. The penetration depth can be reduced and precisely adjusted by using gel pads as spacers.

The maximum applied energy flux density, a local variable for the acoustic pressure signal measured at the central focal point, is an acoustic field parameter which is often used in clinical practice and scientific studies. In addition to giving information about pressure conditions in the focal area, this figure also provides information about the energy acting in the focal area of the acoustic field. The unit of measurement for energy flux density is millijoule per square millimeter (mJ/mm²).

Different therapy sources

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Values vary according to the preset intensity level and may be rounded. The data for the F10G10 and F7G3 therapy sources are still provisional.