the heart and its gadgets

Measurement techniques

• Electrocardiogram - for cardiac electrophysiology

Electrocardiograph (ECG, or EKG [from the German Elektrokardiogramm]) is a transthoracic interpretation of the electrical activity of the heart over time captured and externally recorded by skin electrodes.^[1] It is a noninvasive recording produced by an electrocardiographic device. The etymology of the word is derived from the Greek electro, because it is related to electrical activity, cardio, Greek for heart, and graph, a Greek root meaning "to write". In English speaking countries, medical professionals often write EKG (the abbreviation for the German word elektrokardiogramm) in order to avoid confusion with EEG

• Sphygmomanometer and stethoscope - for blood pressure 

A sphygmomanometer or blood pressure meter is a device used to measure blood pressure, comprising an inflatable cuff to restrict blood flow, and a mercury or mechanical manometer to measure the pressure. It is always used in conjunction with a means to determine at what pressure blood flow is just starting, and at what pressure it is unimpeded. Manual sphygmomanometers are used in conjunction with a stethoscope.

• Pulse meter - for cardiac function (heart rate, rhythm, dropped beats)

A heart rate monitor is a personal monitoring device which allows a subject to measure his heart rate in real time or record his heart rate for later study. Early models consisted of a monitoring box with a set of electrode leads which attached to the chest.

• Pulse - commonly used to determine the heart rate in absence of certain cardiac pathologies

 In medicine, one's pulse represents the tactile arterial palpation of the heartbeat by trained fingertips. The pulse may be palpated in any place that allows an artery to be compressed against a bone, such as at the neck (carotid artery), at the wrist (radial artery), behind the knee (popliteal artery), on the inside of the elbow (brachial artery), and near the ankle joint (posterior tibial artery). The pulse can also be measured by listening to the heart beat directly (auscultation), traditionally using a stethoscope.

• Heart rate variability 

- used to measure variations of time intervals between heart beats

• Nail bed blanching test 

- test for perfusion

• Vessel cannula or catheter pressure measurement 

- pulmonary wedge pressure or in older animal experiments