Electrodermal Screening (EDS) is a method promoted by some alternative medicine practitioners to assess a person’s health status. This technique uses a device to measure electrical characteristics on the skin, typically at points related to traditional acupuncture. EDS is also known as Electroacupuncture according to Voll (EAV), Galvanic Skin Response (GSR) testing, or bioresonance testing. The method is based on non-traditional theories suggesting a link between these electrical measurements and the functional state of internal organs. This article examines the claims made about EDS and analyzes the scientific evidence regarding its legitimacy as a diagnostic tool.
Defining Electrodermal Screening and Its Claims
The theory behind Electrodermal Screening is rooted in the concept of energy pathways, or meridians, originating in traditional Chinese acupuncture. Proponents suggest these pathways carry a measurable “energy flow,” and imbalances indicate disease or dysfunction. The EDS device measures electrical resistance or conductivity at specific acupuncture points near the skin’s surface. This measurement is supposedly correlated to the health of an internal organ system associated with that meridian.
Practitioners assert that resistance readings can reveal issues like allergies, nutritional deficiencies, or chronic infections by identifying energy blockage or weakness. The device is also used to test the compatibility of remedies or supplements; a substance is deemed beneficial if it causes the electrical reading to return to a “normal” range. This mechanism positions EDS as a tool for evaluating the body’s “bioenergetic” state.
The Standard Procedure for EDS Testing
An EDS session begins with the patient holding a metal rod or plate, which acts as the ground electrode to complete an electrical circuit. The practitioner uses a specialized probe or stylus, the second electrode, to touch specific points, usually on the hands and feet. These points are theorized to correspond directly to the terminal ends of the body’s energy meridians. A small electrical current passes through the circuit, and the device registers a numerical reading of the skin’s electrical resistance.
Readings are displayed on a scale from 0 to 100; values between 45 and 55 are interpreted as a healthy balance for the corresponding organ system. Readings deviating significantly from this range are considered abnormal. A high reading suggests inflammation or over-activity, while a low reading suggests degeneration or weakness. The practitioner systematically tests dozens of points, using the numerical output to interpret the patient’s supposed energetic imbalances.
Lack of Scientific Support and Validity
Electrodermal Screening devices are not supported by consistent scientific evidence for diagnostic use. Major medical organizations consider EDS an unproven diagnostic tool. The fundamental theory that a measurable “energy flow” along meridians relates directly to internal organ pathology lacks biological plausibility in modern anatomy and physiology. There is no known physical basis for the claimed link between electrical resistance at specific skin points and a distinct internal disease state.
The electrical measurement recorded by EDS devices is primarily a measure of simple Galvanic Skin Response (GSR), or skin conductance. Skin conductance is highly reactive and variable, influenced by superficial factors unrelated to internal organ health.
Factors Affecting EDS Readings
- The patient’s hydration level
- The presence of skin creams
- The temperature of the room
- The pressure applied by the practitioner’s probe
This high variability makes the results inherently unreliable and non-reproducible, failing a basic requirement for any scientific diagnostic method. Furthermore, controlled studies have failed to validate the claims made by EDS practitioners. For example, one study testing a common EDS device (Vegatest) for allergy diagnosis found it could not distinguish between individuals with known allergies and those without. The electrodermal results showed no correlation with established allergy testing methods, such as skin prick tests. The device was unable to consistently or accurately diagnose participants, highlighting the randomness of the results.
Regulatory Oversight and Consumer Safety
The regulatory status of Electrodermal Screening devices in the United States reflects the scientific consensus regarding their lack of diagnostic validity. The U.S. Food and Drug Administration (FDA) has not approved these devices for diagnosing any specific disease, allergy, or medical condition. Many machines gain market clearance only as basic Galvanic Skin Response or biofeedback devices. This classification acknowledges their ability to measure skin electrical activity but explicitly prohibits their use for medical diagnoses.
The FDA has taken enforcement action against companies and practitioners for illegally promoting and using these devices as diagnostic tools. The primary consumer safety risk associated with EDS is the danger of misdiagnosis or the delay of effective, evidence-based medical care. Relying on unproven EDS results for serious conditions can lead patients to forgo necessary conventional treatments, potentially resulting in severe consequences, particularly in cases of progressive diseases like cancer.