Lithotripter (ESWL) Product

Overview

A lithotripter breaks kidney stones without surgery. It focuses pulses of acoustic energy — shock waves — through the body wall onto a stone, hammering it from outside the patient until it crumbles into fragments small enough to pass naturally. The trick is geometry: the energy must spread harmlessly through tissue everywhere except a small focal point on the stone, where it converges hard enough to fracture mineral. Imaging keeps that focal point on target throughout the session.

The Shock-Wave Head generates and focuses each pulse, coupling it into the body through a water cushion pressed to the skin. The High-Voltage Supply charges a capacitor and dumps it into the generator on every trigger, setting the energy and rate. The Imaging System system finds and tracks the stone, the Patient Positioning Table moves the patient so the stone sits exactly on the focus, and the Control Console ties triggering, imaging and positioning together while the Cooling Unit unit removes the heat all of this produces.

How it works

The shock wave starts as a fast electrical discharge. The High-Voltage Supply charges the HV Energy Capacitor to several kilovolts, then IGBT Power Module switching dumps that energy into the Electromagnetic Shock Generator, whose coil repels a metal membrane to launch a pressure pulse into the Degassed Coupling Water. The pulse steepens into a true shock and the Parabolic Reflector and Acoustic Lens converge it onto a focal point a few millimeters across. Degassed water matters here: bubbles would scatter the wave and waste energy before it reaches the patient. At the stone, the rapid pressure rise plus cavitation collapse cracks the mineral over thousands of pulses.

Aiming is everything, because the focal point is fixed and the stone is not. The Imaging System system localizes the stone with a fluoroscopic C-arm and an inline ultrasound probe, both registered to the focus, and the Patient Positioning Table then drives the patient in three axes through its Positioning Axis Drive units until the stone sits on target. The Control Console gates each shock to a chosen point in the cardiac cycle to avoid triggering arrhythmias, ramps energy up gradually, and lets the operator re-image between bursts as fragments shift. The Cooling Unit unit keeps the generator and high-voltage electronics in range across a session of thousands of pulses.