Extracorporeal Shockwave Therapy PDF

Dr. Doaa Said Sallam PT, PhD. Lecturer of Physical Therapy for Basic Science Department Horus University-Egypt.  AGENDA ▪ Definition ▪ Types of ESWT. ▪ Shockwave energy, Depth of penetration, frequency. ▪ Mechanisms of Action of ESWT. ▪...

Dr. Doaa Said Sallam PT, PhD. Lecturer of Physical Therapy for Basic Science Department Horus University-Egypt.  AGENDA ▪ Definition ▪ Types of ESWT. ▪ Shockwave energy, Depth of penetration, frequency. ▪ Mechanisms of Action of ESWT. ▪ Physiological and therapeutic effects of ESWT. ▪ Indications. ▪ Contraindications. ▪ Advantages of ESWT. ▪ Adverse effects of ESWT. ▪ Clinical application of ESWT. 2  Definition Extracorporeal means outside body. ESWT is defined as a noninvasive treatment that involves the application of pressure mechanical waves outside of the body (extracorporeal) that violently impact (shock) biologic tissues for therapeutic purposes. Shock waves are delivered in a sequence of biphasic, high-energy acoustic pulses that generate transient pressure disturbance and propagate rapidly in three-dimensional space. 3  Shock waves are high-amplitude sound waves travelling faster than speed of sound propagate in tissue with a sudden rise from ambient pressure to maximum compressive pressure (P+) followed by a lower tensile pressure (P–) relaxation phase. A shock wave is a pressure or acoustic wave characterized by ▪ High pressure (P) and ▪ Short rise time (RT) and 4 ▪ Short pulse duration (PD).  ESWT were introduced in medical therapy approximately 30 years ago in order to disintegrate kidney stones. Over the last 15 years, extracorporeal generated shockwaves have been used in many fields of medicine due to their versatility and ability to stimulate healing processes. Difference between lithotripsy and orthotripsy 1. Lithotripsy is the original and classic use of ESWT that uses acoustic sound waves in urology to break up kidney and ureteral stones. 2. Orthotripsy is to stimulate soft tissue healing using shock waves. 5 5  6 6  Shockwave Characteristics: 1. Compression phase: Positive peak pressure (between up to 100 megapascals (MPa)). Pressure is commonly measured and expressed in units of megapascal (Mpa) or bar, where 10 bar is equivalent to 1 MPa. 1MPa is about 10 times atmospheric pressure. 2. Tensile phase: pressure rapidly falls to a negative peak pressure of about 5-10 Mpa reflected in low tensile amplitude- relaxation phase. (approximately 10% of positive pressure). 3. Fast pressure rise time (usually less than 10 ns (nanoseconds). 4. Short pulse duration (usually about 10 microseconds). 5. Narrow effective beam (2-8 mm diameter). 7 8  Production of ESWT Four types of generators are used to produce extracorporeal shock waves: electrohydraulic, electromagnetic, piezoelectric, and ballistic. The first three generators rest on the conversion of electrical energy to mechanical energy and generate focused shock waves (f-ESWT) that is applied over a small and precise location. The fourth generator, called ballistic, rests on the pneumatic principle and generates an unfocused or radial shock waves to the tissue. 9  Types of shockwaves 1. Non-Focused or Radial or Dispersive or Soft shockwave (r-ESWT) 2. Focused or Hard shockwave (f-ESWT) 10 11  FOCUSED 12  1. Non-Focused or Radial or Dispersive or Soft shockwave (r-ESWT): Radial shock waves are created using a ballistic generator (compressed air to drive and accelerate a projectile) or electromagnetic. Pressure pulses rise longer than focused in range of 0.1–10 Mpa. The energy generated by the pressure wave is absorbed into the skin approximately 3-5 cm deep and spreads a wider beam to a larger target area. In physical therapy, r-ESWT is a better choice than f-ESWT because it is more affordable and easier to administer. The radial or dispersive wave sometimes called a “soft” shockwave. 13 14  2. Focused or Hard shockwave (f-ESWT): Focused shockwaves are generated inside the applicator and then focused by a lens and transmitted into the tissue, waves are created using electrohydraulic, electromagnetic, and piezoelectric systems. Pressure pulses rise rapidly in range of 10–100 MPa and concentrate the acoustic energy beam with a penetration depth of approximately 5-12 cm. Focused shock waves amplitudes are approximately 120 times larger than those achieved by radial shock waves. Focused waves are sometimes also referred to as “hard” shockwaves. 15  Piezoelectric crystals 16  Focused Radial High energy shockwave low- to medium-energy shockwave High peak pressure. Lower peak pressure. Shorter rise time. Longer rise time. Focused application. Unfocused application. Painful and sometimes needs anesthesia. Less painful so can be administrated without anesthesia. Refocusing is periodically necessary. Focal point is included in the wave propagation area. 17  Shockwave energy The mechanical or acoustic energy (E) contained in a shock wave is expressed in millijoules (mj). Energy Flux Density (EDF): Degree of energy transmitted to the tissues. It is the amount of mechanical acoustic energy (E) per unit area (A) per shock (EDF = E/A). EFD is measured in millijoules per square millimeter (mj/mm2). 18  The EFD level may be classified as Focused shock waves have much low, medium, or high. larger EFDs than radial shock waves because they contain much more ▪ Low (