Use of the Walton-Brodie strain gauge arch to measure contractile force during anaesthesia.

The Walton-Brodie strain gauge arch is an instrument that quantitatively measures CF. Like many methods, the strain gauge arch is affected by loading conditions and heart rate. Nevertheless, this methodology, when properly used, has proved very useful in describing the direct action of anaesthetic drugs. Knowledge from strain gauge arch use has stimulated research to explain the negative inotropic effect of anaesthetics and helped clinicians understand the cardiovascular effects of drugs that they may wish to use.