Introduction to Basic Concept of Electrical Stimulation Current PDF

Introduction to Basic Concept of Electrical Stimulation Current Dr. Haitham Elessawy Faculty of Physical Therapy Electrotherapy 1 (PTBA 329) 1 Learning Outcomes - LOs Understand the concept behind principles of electrotherapy. Describe the relationships between t...

Introduction to Basic Concept of Electrical Stimulation Current Dr. Haitham Elessawy Faculty of Physical Therapy Electrotherapy 1 (PTBA 329) 1 Learning Outcomes - LOs Understand the concept behind principles of electrotherapy. Describe the relationships between technical terminology and sensory responses to electrical stimulation and accurately match each term with the sensation that it produces. Evaluation /applying of modalities in relation to the diseases. Demonstrate the e ective electrotherapy treatment methods with precautions. Perform safe application of electrical apparatus. Apply suitable treatment parameters for e ective and safe delivery of electric stimulation. 2 ff ff Course Assessment Assessment Marks % Grade Quizzes & Assignments 20 10% Mid-term Exam 20 10% Oral Exam 30 15% Practical Exam 30 15% Final Written Exam 100 50% Total 200 100% 3 Electrical Stimulation Terms Basic Terminology ➡ Electricity :A form of energy that exhibits magnetic, chemical, mechanical, and thermal e ects; formed from the interaction of positive (+) and negative (−) charges. ➡ Electrical Current : A ow of charged particles electron (e-)/ions from higher to lower concentration. ➡ Electrical stimulation : Application of therapeutic electrical current devices to stimulate excitable tissues, with the aim of producing physiological reaction for therapeutic bene ts. ➡ Electrotherapy: Application of electrical energy for therapeutic purposes. 4 fl ff fi ➡ Intensity (Magnitude) of Current :It is the rate of an (e-) ow through a conductor from cathode (-) to anode (+), per second. Measured in Ampere. ➡ Resistance: is a quan ta ve degree of opposi on to the ow of electron. It is directly proportional to length and inversely proportional to cross section area of a conductor. ➡ Ohm: (Ω) unit to measure resistance to current ow. 5 ti ti ti fl fl fl  General Therapeutic Uses of Electrical stimulation 1. Pain management : TENS (Transcutaneous Electrical Nerve S mula on) 2. Facilitate func on (i.e. walking, grasping etc.) : FES (Func onal Electrical S mula on) 3. related muscle atrophy, improve local blood ow : EMS (Electrical Muscle S mula on) 4. Increasing muscle strength or to recover motor control : NMES (Neuromuscular Electrical S mula on) 6 ti ti ti ti ti ti ti ti ti ti fl Classification of Electrotherapy Electro Physical Agents - EPA’s Thermal Non Thermal Electrical stimulation Agents Agents modalities 7 8 Basic Model of Electrotherapy Intervention Clinical decision making model All electrotherapy modalities (with the exception of biofeedback) involve the introduction of some physical energy into a biologic system. This energy brings about one or more physiological changes, which are used for therapeutic bene t. 9 fi Electrotherapeutic Windows The ideal 'dose' 10 Acute vs Chronic 11 Another view on therapeutic windows concept Arndt-Schulz rule or law 12 Parameters of electrical Current stimulation ➡ 1) Types of currents: Alterna ng vs. direct current. ➡ 2) Frequency. ➡ 3) Intensity of current. ➡ 4) Time dependent parameter (Pulse a ributes). ➡ 5) Tissue impedance. ➡ 6) Current density. ➡ 7) Electrodes considera ons. 13 ti ti tt  1-Current Types Direct current Alternating Current Pulsed current (PC) (DC) (AC) Def. Continuous The e- flow in alternating pulsatile current unidirectional flow of e-’s directions in both sides of An interrupted current, whereby the toward (+) pole isoelectric line from (–) current flows in a series of pulses and (+) pole. separated by periods when no current flows. can take on the direction characteristics of AC or DC current. Shape Monophasic Biphasic Monophasic or biphasic Types “Galvanic current” Current can be Groups of pulses are interrupted for Interrupted direct symmetrical, short periods of time (inter-pulse current or “ asymmetrical e.g. intervals) & repeat. Russian current Interrupted galvanic” TENS, Interferential current Uses Iontophoresis and Stimulate of Pain relief Pain relief denervated muscle; Neuromuscular Neuromuscular stimulation stimulation. Wound healing 14  Current Types Direct Alternating Pulsatile Current (DC) Current (AC) Current (PC) 15 1-Alternating vs. Direct Current Physiological e ect 16 ff Waveforms Waveform is a graphic representa on of “shape, direc on, amplitude, dura on and frequency” of the electrical current 1-Waveforms Shape !Sine wave !Rectangular wave !Square wave !Triangular wave !Saw tooth wave !Trapezoid wave !All types of current may take on any of the waveform 17 ti : ti ti Waveforms related parameters Symmetrical vs. Asymmetrical waveforms ! Symmetrical waveforms :Each phase Equal in amplitude, Equal in shape and size Net charge is zero ! Asymmetrical waveforms : Each phase Not equal in amplitude, Not equal in shape &size Net charge > than zero. 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 Thank You 34