Extracorporeal Shock Wave Lithotripsy (ESWL) is a non-invasive therapy for treatment of renal calculi which is administered on an outpatient basis. The procedure is administered in an outpatient setting, does not require any surgery or anaesthetic, and is relatively comfortable both physically and economically for patients.

 

The TMC-X4 is a modular extracorporeal shock wave lithotripter with integrated Shock Wave generator, Patient Positioning Table and Fluoroscopy X-Ray U-Arm. The basic system consists of main ESWL unit, Shock Wave Generator, Fluoroscopy X-Ray U-Arm and an integrated treatment table. The x-ray u-arm imaging system is incorporated for performing stone localization and monitoring. An X - Ray monitor is used for positioning the shock waves to the patient's renal calculus. The TMC-X4 is small and integrated and can be used in any equipped room.

All lithotripsy machines have basically 4 basic components:

• (1) A Shockwave Generator
• (2) A Focusing System
• (3) A Coupling Mechanism
• (4) An Imaging/Localization Unit.

Shockwave Generator

Shockwaves are generated using electrohydraulic principal, in the TMC-X4. This is the original method of shock wave generation, electro hydraulic, means that the shock wave is produced via spark-gap technology. In an electro hydraulic generator, a high-voltage electrical current passes across a spark-gap electrode located within a water-filled reflector. The discharge of energy produces a vaporization bubble, which expands and immediately collapses, thus generating a high-energy pressure wave.

 

Focusing Systems (Reflector)

The focusing system is used to direct the generator-produced shockwaves at a focal volume in a synchronous fashion. The basic geometric principle used in most lithotripters is that of an ellipse. But in lithotripters manufactured by TMC Europa Ltd., a further advanced geometry of dual focus ellipso paraboloid is used. Shockwaves are created at one focal point (F1) and converge at the second focal point (F2). The target zone, or blast path, is the 3-dimensional area at F2, where the shockwaves are concentrated and fragmentation occurs. The Figure 1-1-1 below shows the focussing reflector.

 

Coupling Mechanisms

In the propagation and transmission of a wave, energy is lost at interfaces with differing densities. As such, a coupling system is needed to minimize the dissipation of energy of a shock wave as it traverses the skin surface. The usual medium used is water, as this has a density similar to that of soft tissue and is readily available. In the TMC-X4 a small water-filled cushion with a silicone membrane fitted in front is used to provide coupling between the shockwave head and the patient. A small amount of Ultrasound Gel or Silicone Oil is used to provide air-free contact. The Figure 1-1-2 below indicated the coupling using the water filled cushion.

 

Localization systems

Imaging systems are used to localize the stone and to direct the shockwaves onto the calculus, as well as to track the progress of treatment and to make alterations as the stone fragments. Fluoroscopy, which is familiar to most urologists, involves ionizing radiation to visualize calculi. The following figure 1-1-3 below illustrates the fluoroscopic localization.

As such, fluoroscopy is excellent for detecting and tracking calcified and otherwise radio-opaque stones, both in the kidney and the ureter. Conversely, it is usually poor for localizing radiolucent stones (eg, uric acid stones). To compensate for this shortcoming, intravenous contrast can be introduced or (more commonly) cannulation of the ureter with a catheter and retrograde instillation of contrast (ie retrograde pyelography) can be performed.

The ESWL Procedure

The Lithotripsy procedure is carried out as an OPD procedure which takes around an hour per session, and usually 3000 shockwaves are applied during each session of Lithotripsy, to the renal calculus.

This is the average treatment protocol to be observed by the Extracorporeal Shock Wave therapist, some patients may require more sittings to pulverise the larger or multiple renal calculi. The extra numbers of sittings required are decided by the physician depending on the patient's state.

 

Your search for a reliable supplier of ESWL equipment ends here us the following links to get more information:

• To know the various models click here...
• To get a price Quote Click here...
• To get Product catalogs and information Click here...
• To go to Knowledge base click here...
• To get Support please click here..

 

Conclusion:

Extracorporeal shock wave lithotripsy (ESWL) is a non-invasive method in which high intensity sound waves (shock waves) are generated outside of the patient body and then focused on the stone within the kidney or ureter.The focal point of the shock wave is fixed, and the patient is moved so that the stone (imaged by fluoroscopy or ultrasound) rests at the focal point (F2 for electro hydraulic Lithotripters).

 

The urologist controls three parameters; number of shock waves administered on the ESWL, the shock wave repetition rate of the Lithotripter, and the voltage (or energy) of the shock wave generator of the ESWL.The process of stone comminution is monitored by imaging, and treatment is terminated when it is judged that residual fragments are small enough to be voided in the urine or grasped and removed using transurethral or Percutaneous probes. A variety of factors are weighed in determining a treatment protocol, including the number, size, location and suspected composition of the stones, the age and health of the patient, and the type of lithotripter being used.

 

Most ESWL patients are treated as outpatients.As a rule stones between 4mm to 20mm are best treated with ESWL.  For stones between 20-30mm, ESWL is still the first line treatment unless factors of stone composition, location, or renal anatomy shift the balance toward invasive but definite treatment modalities (PCNL or RIRS).  Stones grater than 30mm should be primarily treated by PCNL, unless specific indications for RIRS are present (i.e. bleeding diathesis, obesity, etc).