Shock wave therapy is not a new modality; in its modern electronic form it has been around since the early 1980s, where it was first shown to have beneficial effects on treating kidney and biliary stones, and later on bone and wound healing.
However, despite now being an established medical intervention, questions still persist around the specifics of shock wave therapy. This article explains the difference between focused shock wave (F-SW) and radial pressure wave (RPW) therapy.
What are shock waves?
A shock wave is defined as a moving sound source travelling at more than the speed of sound. A stationary sound wave emits acoustic pressure waves that are evenly distributed in all directions. However, when the sound source is moving, the sound waves in front are compressed, and if the source moves faster than the speed of sound, the compressed waves overlap and create a shock wave, which is heard as a sonic boom.
It was noted that shock waves travel much better through water than they do through air, and that they could affect the body on a cellular level, thereby stimulating its intrinsic healing mechanism. This led to efforts to harness this phenomenon for medical applications, and the resulting technology became commonly known as shock wave therapy.
A brief history of shock wave therapy
Shock wave therapy as we know it first came into practical use in the 1980s, in the form of focused shock wave (F-SW). As with the emergence of any new intervention, there was immediately a great deal of interest – and hype – surrounding it.
Researchers began conducting clinical trials, but with no real guidelines on parameters, results were conflicting. At the same time, therapists were treating through trial and error, with outcomes ranging from very good to poor. This led to a drop in interest during the 1990s, with practitioners becoming disillusioned with F-SW, due also in part to the relative high cost of the devices.
However, with the advent of modified modalities, better research, and the technology to study the therapeutic effects on a molecular level, interest in shock wave therapy was rekindled around the end of the 1990s. Manufacturers began building more affordable clinic-based F-SW devices, and therapists became better at incorporating shock wave therapy into their treatments, all of which helped lead to better outcomes for patients.
Then, towards the end of the 1990s, a new technology emerged: radial pressure wave (RPW) therapy. Just as F-SW machines were becoming more affordable, RPW devices turned out to be even cheaper to produce and answered the demand from clinicians for a shock wave technology that could be used to treat on a more superficial level over larger areas.
Now shock wave therapy is an accepted and valued intervention that generates positive outcomes, supported by a wide range of clinical studies, and with far more affordable devices available to practitioners.
The differences between focus shock wave and radial pressure wave therapy
While focused shock wave (F-SW) therapy and radial pressure wave (RPW) therapy are often referred to together as ‘shock wave’, or extracorporeal shock wave therapy, only one is truly worthy of the definition.
F-SW delivers maximum energy at a focal point in the tissue at a depth of between 4-6cm, though some devices can achieve therapeutic energy values down to 12cm. Conversely, RPW delivers maximum energy at the surface of the skin, which then travels radially into the body up to a depth of 5-6cm. If we look at the physical properties of the two interventions, we can see they are completely different (Fig. 1).
Firstly, a focused shock wave will produce a pressure peak in the range of 10-100 Mega-Pascals (MPa), compared to the positive peak pressure of 0.1-1 MPa for a radial pressure wave – 100 times the amount of energy. Furthermore, the time taken for a focused shock wave to reach that peak, as well as its overall pulse duration, is far shorter than that of an RPW.
Therefore, unlike F-SW, a radial pressure wave is not a ‘true’ shock wave.
Additionally, while both technologies involve the conversion of electrical energy into mechanical energy, the ways in which focused shock waves and radial pressure waves are generated and delivered are also different.
F-SW machines generate shock waves using either electrohydraulic, electromagnetic, or piezoelectric technology. The shock waves are generated in water contained in a standoff attached to a handheld applicator. These waves are then focused through a lens and transmitted into the tissue.
Most RPW machines generate radial pressure waves using either oil or air compressors. During use, the compressed air is released via a valve into the barrel of a hand-held applicator which contains a small projectile. As the valve opens and closes very quickly, the projectile is driven by the compressed air into a transmitter at the end of the applicator, where the kinetic energy is converted into acoustic shock waves.
To learn more about the effects and applications of shock wave therapy:
Tiba ya mawimbi ya mshtuko sio njia mpya; katika fomu yake ya kisasa ya elektroniki imekuwa karibu tangu mwanzoni mwa miaka ya 1980, ambapo ilionyeshwa kwanza kuwa na athari nzuri kwa kutibu viti vya figo na bile, na baadaye kwa uponyaji wa mifupa na jeraha. Hata hivyo, licha ya kuwa hatua ya kitiba iliyoanzishwa sasa, bado kuna maswali kuhusu jinsi tiba ya mawimbi ya mshtuko inavyoweza kutumiwa. Maelezo ya juu ya jinsi ya kutumia Focused Shock Wave (FWS) na Radial Pressure Wave (RPW) Mawimbi ya mshtuko ni nini? Wimbi la mshtuko hufafanuliwa kama chanzo cha sauti kinachoenda kwa kasi zaidi ya sauti. Mawimbi ya sauti yasiyo na mwendo hutokeza mawimbi ya shinikizo la sauti ambayo husambazwa kwa usawa katika pande zote. Hata hivyo, wakati chanzo cha sauti kinasonga, mawimbi ya sauti mbele hufinyangwa, na ikiwa chanzo hicho kinasonga kwa kasi kuliko kasi ya sauti, mawimbi hayo hufinyangwa na kuunda wimbi la mshtuko, ambalo husikika kama mlipuko wa sauti. Kwa mfano, kuna uwezekano mkubwa kwamba mawimbi ya mshtuko yanasafiri vizuri kupitia maji kuliko hewa, na kwamba yanaweza kuathiri mwili katika kiwango cha seli, na hivyo kuchochea utaratibu wake wa asili wa uponyaji. Hilo liliongoza kwenye jitihada za kutumia jambo hilo katika matibabu, na teknolojia hiyo ikajulikana kama tiba ya mawimbi ya mshtuko. Tiba ya Shock Wave (SWT) - Tiba ya Shock Wave (SWT) ilitumiwa kwa mara ya kwanza katika miaka ya 1980, katika fomu ya Shock Wave (FWT). Kama ilivyo na kuibuka kwa uingiliaji wowote mpya, kulikuwa na mara moja kiasi kikubwa cha maslahi <unk> na hype <unk> kuzunguka yake. Watafiti walianza kufanya majaribio ya kitiba, lakini kwa kuwa hakukuwa na miongozo halisi kuhusu vigezo, matokeo yalikuwa yanayopingana. Wakati huohuo, wataalamu wa tiba walikuwa wakitibu kwa kujaribu na kukosea, na matokeo yalikuwa kuanzia mazuri sana hadi mabaya. Hii ilisababisha kupungua kwa maslahi katika miaka ya 1990, na watendaji wakivunjika moyo na FMS, kwa sababu pia kwa sehemu ya gharama ya juu ya vifaa. Hata hivyo, kwa kuibuka kwa njia zilizobadilishwa, utafiti bora, na teknolojia ya kusoma athari za matibabu katika kiwango cha molekuli, maslahi katika tiba ya mawimbi ya mshtuko yalianzishwa tena karibu na mwisho wa miaka ya 1990. Watengenezaji walianza kujenga vifaa vya F-SW vya bei nafuu zaidi, na wataalamu walianza kuingiza tiba ya mawimbi ya mshtuko katika matibabu yao, yote ambayo yalisaidia kuongoza matokeo bora kwa wagonjwa. Katika miaka ya 1990, teknolojia ya radial pressure wave (RPW) ilibadilika. Wakati mashine za F-SW zilipokuwa zinapatikana kwa bei nafuu, vifaa vya RPW viligundua kuwa vya bei nafuu zaidi kutengeneza na kujibu mahitaji kutoka kwa madaktari kwa teknolojia ya wimbi la mshtuko ambayo inaweza kutumika kutibu kwa kiwango cha juu zaidi juu ya maeneo makubwa. Sasa tiba ya mawimbi ya mshtuko ni uingiliaji uliokubaliwa na wenye thamani ambao hutokeza matokeo mazuri, unaungwa mkono na utafiti mbalimbali wa kliniki, na na vifaa vya bei nafuu zaidi vinapatikana kwa watendaji. "Tiba ya ""Focus Shock Wave"" na ""Radial Pressure Wave"" ni aina ya matibabu ya mawimbi ya mshtuko, ambayo kwa kawaida huitwa ""Extracorporeal Shock Wave Therapy.""" F-SW hutoa nishati ya juu katika sehemu ya fomu katika tishu katika kina cha kati ya 4-6cm, ingawa baadhi ya vifaa vinaweza kufikia thamani ya nishati ya matibabu chini ya 12cm. RPW hutoa nishati ya juu ya ngozi, ambayo kisha husafiri radially ndani ya mwili hadi kina cha 5-6cm. Kama sisi kuangalia mali ya kimwili ya uingiliaji mbili, tunaweza kuona wao ni tofauti kabisa (Fig. 1) Kwa mfano, mawimbi ya mshtuko wa radial yanaweza kusababisha shinikizo la juu la 10-100MPa, ikilinganishwa na shinikizo la juu la 0.1MPa kwa wimbi la shinikizo la radial. Kwa kuongezea, muda unaotumiwa kwa wimbi la mshtuko kufikia kilele hicho, pamoja na muda wake wa jumla wa msukumo, ni mfupi sana kuliko ule wa RPW. Kwa hiyo, tofauti na F-SW, radial shinikizo wimbi si <unk>kweli<unk> shock wimbi. Kwa kuongezea, wakati teknolojia zote mbili zinahusisha kubadilisha nishati ya umeme kuwa nishati ya mitambo, njia ambazo mawimbi ya mshtuko na mawimbi ya shinikizo ya radial hutengenezwa na kutolewa pia ni tofauti. Mashine za F-SW hutokeza mawimbi ya mshtuko kwa kutumia teknolojia ya umeme, umeme, au piezoelectric. Mawimbi ya mshtuko hutokezwa katika maji yaliyo katika kizuizi kilichounganishwa na kiunganishi cha mkono. Kisha mawimbi hayo hukabiliwa kupitia lensi na kupelekwa kwenye tishu. Mashine nyingi za RPW hutokeza mawimbi ya shinikizo la radial kwa kutumia compressors za mafuta au hewa. Wakati wa matumizi, hewa compressed ni iliyotolewa kupitia valve katika pipa ya applicator mkono uliofanyika ambayo ina projectile ndogo. Kama valve kufunguliwa na kufungwa haraka sana, projectile ni kuendeshwa na hewa compressed katika transmitter katika mwisho wa applicator, ambapo nishati kinetic ni kubadilishwa katika mawimbi ya mshtuko acoustic. Ili kujifunza zaidi kuhusu athari na matumizi ya tiba ya mawimbi ya mshtuko: