String galvanometer

Jump to navigation Jump to search

WikiDoc Resources for String galvanometer

Articles

Most recent articles on String galvanometer

Most cited articles on String galvanometer

Review articles on String galvanometer

Articles on String galvanometer in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on String galvanometer

Images of String galvanometer

Photos of String galvanometer

Podcasts & MP3s on String galvanometer

Videos on String galvanometer

Evidence Based Medicine

Cochrane Collaboration on String galvanometer

Bandolier on String galvanometer

TRIP on String galvanometer

Clinical Trials

Ongoing Trials on String galvanometer at Clinical Trials.gov

Trial results on String galvanometer

Clinical Trials on String galvanometer at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on String galvanometer

NICE Guidance on String galvanometer

NHS PRODIGY Guidance

FDA on String galvanometer

CDC on String galvanometer

Books

Books on String galvanometer

News

String galvanometer in the news

Be alerted to news on String galvanometer

News trends on String galvanometer

Commentary

Blogs on String galvanometer

Definitions

Definitions of String galvanometer

Patient Resources / Community

Patient resources on String galvanometer

Discussion groups on String galvanometer

Patient Handouts on String galvanometer

Directions to Hospitals Treating String galvanometer

Risk calculators and risk factors for String galvanometer

Healthcare Provider Resources

Symptoms of String galvanometer

Causes & Risk Factors for String galvanometer

Diagnostic studies for String galvanometer

Treatment of String galvanometer

Continuing Medical Education (CME)

CME Programs on String galvanometer

International

String galvanometer en Espanol

String galvanometer en Francais

Business

String galvanometer in the Marketplace

Patents on String galvanometer

Experimental / Informatics

List of terms related to String galvanometer

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]


The String galvanometer was one of the earliest instruments capable of detecting and recording the very small electrical currents produced by the human heart and provided the first practical Electrocardiogram (ECG). Moving coil galvanometers were not at the time sufficiently sensitive to record the electrical currents involved.

Willem Einthoven solved the problem by producing a very long filament of negligible mass that conducted the electrical currents from the heart. This filament was acted upon by powerful electromagnets, which caused sideways displacement of the filament in proportion to the current carried. The movement in the filament was measured using sensitive optical devices.

The filament was originally made by drawing out a filament of glass from a crucible of molten glass. To produce a sufficiently thin and long filament an arrow was fired across the room so that it dragged the filament from the molten glass. The filament so produced was then coated with silver to provide the conductive pathway for the current.

The original machine required water cooling for the powerful electromagnets, required 5 people to operate it and weighed some 600 lb. Because the machine was too large to be brought to the patients bedside, the current from the heart was transmitted to the machine using a telephone cable.

Template:WikiDoc Sources