Therapy sources and focal zones made for the indication


The use of focused shock waves is firmly established as an accepted procedure to treat many different conditions. With the increased numbers of indications for shockwave procedures and the expansion of ESWT options, the requirements for the focal zones of shock waves in terms of their penetration depth, strength, shape and volume have risen significantly. The idea that one type of focal zone fits all is therefore no longer in keeping with current user demands. A modern and innovative shock wave system needs to be variable to allow it to be adjusted to the respective target tissue. To meet the demand for successful treatments optimally adjusted to various indications, Richard Wolf GmbH and ELvation Medical GmbH set about developing the right therapy sources and focal zones for many different indications in addition to all-purpose therapy sources. All therapy sources shown in this brochure are optional and were designed for use with the PiezoWave2 system. This allows the treatment concept to be expanded from all-purpose treatments to new therapies in future.


Focal size, explained in termsof standard sizes…

Focal size, therapeutic impact zone, -6dB zone, 5 megapascal (MPa) zone, central penetration depth, maximum/distal penetration depth, energy flux density… all of these terms can be confusing and are often randomly used, also in advertising. But focal zones are defined according to specific standard sizes and technical norms, as shown in the simplified description given below:

The -6dB zone, commonly used to compare measurements and studies, refers to the area in the focal zone where the sound pressure amplitude is at least 50% of the maximum sound pressure amplitude in the central focal point. According to current scientific knowledge, this figure provides no data about the therapeutic impact zone of shock wave therapy. But based on the assumption that a sound pressure amplitude of at least 5MPa is needed to achieve a tissue effect/therapeutic effect in standard ESWT treatments, the 5MPa zone is increasingly considered to be a therapeutic impact zone. According to this definition, the 5MPa zone is the focal sound field area where the sound pressure amplitude is ≥ 5MPa.

The specified maximum penetration depth refers to the respective sound field. The central maximum penetration depth is the distance between the skin surface and the point of maximum sound pressure when using a gel pad which ensures the greatest penetration depth. The maximum penetration depths of the -6dB and 5MPa zones refer to the distance between the skin surface and the distal “end” of the respective focal zone, again while using a gel pad with the greatest penetration depth. Penetration depths can be precisely varied or reduced, using gel pads as spacers.

The maximum applied energy flux density is another sound field parameter often used in practice and in studies; it is a variable for the central focal point obtained from the sound pressure signal measured at that point. It provides additional information about energy levels in the focal sound field in addition to sound pressure conditions in the focal area. The unit of measurement for energy flux density is millijoule per square millimeter (mJ/mm²).

The different therapy sources

Click on the graphics to enlarge them.

Values vary with the intensity preselection and can be rounded. Data for the therapy sources F10G10 and F7G3 are for the time being.