The ultrasonic therapy appertains to the procedures of the Physical Therapy.
It is a part of mechanical therapy, because ultrasound consists of acoustic waves (longitudinal, wavelike spreading of smallest pressure variations of a medium as for example air or liquids) with a high frequency.
In addition the ultrasonic therapy can be used as thermotherapy.
The ultrasonic therapy is also, in the widest sense, a form of the electrotherapy. This justifies itself, because the ultrasound is being obtained from electric energy.
The therapy form is used particularly with chronically degenerative illnesses of the human movement apparatus.
This abstract shall give a basic overview of the ultrasound and of the transfer chain; from the ultrasound to the human skin.
Table of Contents
A Introduction
B Basics of Ultrasound
B.1 Selected definitions of terms
C Basics of the Ultrasonic Therapy
C.1 Effects at and in the human tissue
C.2 The effect spectrum and indications
D Basics of the Piezoceramic Sensor
D.1 Historical excursion
D.2 Principles of functioning
D.3 Production and material
D.4 Forms used and their basic oscillation
E Medical therapy transducer
Objectives and Topics
This technical investigation provides a fundamental overview of ultrasonic technology within medical therapy, specifically addressing the physical principles of ultrasound and the functional components of therapeutic transducers. The document aims to clarify technical basics required for mandatory safety inspections of medical therapy devices.
- Fundamental physical principles of sound and ultrasonic waves.
- Mechanisms and effects of ultrasonic therapy on human tissue.
- Technical operation and piezoelectric characteristics of sensors/actuators.
- Manufacturing processes for piezoceramic components.
- Structural components and application examples of medical ultrasound transducers.
Excerpt from the book
C.1 Effects on and in the human tissue
Ultrasonic therapy produces different effects on the human body and in human tissue. In general, a distinction is made between two effects:
Mechanical effects: The ultrasound output or ultrasonic waves applied to human tissue produce contractions and expansions in the elastic human tissue using the same frequency (1 MHz or 3 MHz). This effect is also referred to as a micro-massage. The micromassage causes a volume change in cells, increases cell membrane penetrability and, thus, an increase in the exchange of metabolic products. Blood circulation is aided and accelerated by a micro-massage, thus achieving better “sustenance” of the tissue.
Thermal effects: The thermal effects (warming of body tissue) are a result of the various characteristics (density, fat and water content) of the tissue types. The temperature increase is approximately proportional to the density and specific capacity of the tissue. Together with the absorption coefficient, the sound energy radiated into the tissue is the decisive parameter with regard to the level of warming of the tissue. The greatest thermal effect occurs at the boundary layer of various tissue structures due their differing impedance (resistance exerted on the sound wave). The higher the absorption coefficient, the greater the warming effect in the tissue.
Chapter Summaries
A Introduction: Outlines the scope of ultrasonic therapy within physical medicine and establishes the necessity of technical knowledge for legally required safety inspections.
B Basics of Ultrasound: Defines key physical concepts such as frequency ranges, wave propagation types, acoustic impedance, and the mathematical relationships between sound velocity and frequency.
C Basics of the Ultrasonic Therapy: Explains the clinical implementation of ultrasound, detailing the interaction between high-frequency generators, transducers, and human tissue.
D Basics of the Piezoceramic Sensor: Covers the historical development, functional principles of the direct/inverse piezoelectric effect, and the industrial manufacturing process of ceramic oscillators.
E Medical therapy transducer: Describes the physical construction and main components of a standard medical ultrasound transducer used in therapeutic practice.
Keywords
Ultrasound, Ultrasonic Therapy, Piezoelectric Effect, Piezoceramic Sensor, Mechanical Effects, Thermal Effects, Acoustic Impedance, Medical Device Directive, Transducer, Micromassage, Longitudinal Wave, PZT, Absorption Coefficient, Medical Technology, Safety Inspection.
Frequently Asked Questions
What is the primary focus of this document?
The document serves as a technical investigation into the physical and functional fundamentals of ultrasound equipment used in medical therapy, primarily to support the understanding required for safety-related inspections.
What are the main thematic fields covered?
The main themes include the physics of ultrasonic waves, the physiological effects of ultrasound on human tissue, the piezoelectric principle, and the technical construction of medical transducers.
What is the primary goal of this research?
The goal is to provide a clear, technical overview of how ultrasonic therapy works, from the generation of sound waves via piezoelectric components to their interaction with human biological tissue.
Which scientific methods are discussed?
The text employs physical analysis and technical documentation, detailing wave propagation formulas, impedance calculations, and the industrial material science behind PZT-based piezoceramics.
What is addressed in the main technical section?
The main section details the operational principles of piezoceramic sensors, including their manufacturing process, polarization, and how they convert electrical energy into mechanical oscillations for therapy.
Which keywords define this work?
Key terms include Ultrasound, Piezoelectric effect, Acoustic impedance, Transducer, Piezoceramic sensors, and Medical therapy applications.
How does the piezoelectric effect work in this context?
The inverse piezoelectric effect is utilized: an alternating voltage is applied to a crystal, causing it to change its shape geometrically, which subsequently generates sound waves in the ultrasonic range.
Why is the choice of coupling medium important?
Media like ultrasound gel are required to minimize transition resistance between the transducer and the skin, ensuring the most efficient possible transfer of acoustic energy into the tissue.
- Arbeit zitieren
- Thomas Lekscha (Autor:in), 2010, Ultrasound for medical therapy devices, München, GRIN Verlag, https://www.grin.com/document/158611
