Table 1.
Overview of different non-invasive methods for office and out-of-office blood pressure measurement.
| Method | Device/Components | Basic Principles of Measurement | Advantages | Disadvantages |
|---|---|---|---|---|
| Mercury Sphygmomanometer | Sphygmomanometer and auscultation by observer | Manual inflation and deflation of the cuff and auscultation of Korotkoff sounds. First sound appearing is the systolic blood pressure, the complete disappearance of the sound indicates diastolic blood pressure | Gold-standard for non-invasive brachial blood pressure measurement. Reference device in validation studies for single measurement comparisons | Safety and economic concerns related to mercury use. Prone to observer related errors. No ABPM * possible |
| Aneroid Sphygmomanometer | Sphygmomanometer and auscultation by observer | Lever and belly system instead of mercury sphygmomanometer | No mercury. Low-priced devices |
Prone to observer related errors. No ABPM possible |
| Oscillometric or auscultatory automated BP devices | Monitor including cuff and bladder (Different validated models commercially available) | Oscillometric pressure changes of cuff pressure or Korotkoff sounds are registered by electronic sensors in the cuff, and BP is calculated by device-specific algorithms ABPM by single intermittent measurements over 24 h, usually every 20 to 30 min |
Cost-effective. Standard in most clinical settings. Specific devices for ABPM available. Devices can be used for at-home blood pressure measurement. |
Different measurement protocols available. Large number of non-validated devices on the market. Discomfort for the patient. Intermittent measurement in case of ABPM. |
| Pulse-Transit Time Measurement (PTT) | Monitor, Finger-photoplethysmograph, ECG (e.g., Somnotouch-NIBP (Somnomedic GmbH, Randersacker, Germany)) |
Time-interval between R-wave on the ECG and the arrival of the corresponding pulse wave at the finger-photoplethysmograph (PTT) can be calculated. After calibration to a single standard, BP measurement changes in PTT are translated into changes of BP values according to specific algorithms. Beat-to-beat BP calculation. |
Less discomfort for patients. Device for ABPM. Beat-to-beat blood pressure measurement possible. 24h-ECG, pulse oximetry and actigraphy as additional information over 24 h. |
Validated for single measurements. Seems to result in higher BP values, when used over 24 h compared to standard devices. More complex analysis of examinations. |
| Volume-clamp-technique Finapres (FINger Arterial PRESsure) |
Finger-cuff and bladder, Finger-plethysmograph (Finapres (Finapres Medical Systems BV, Enschede, Netherlands)) | Finger arterial pressure and waveform is measured using a finger cuff and an inflatable bladder in combination with a finger-plethysmograph. After calibration to standard BP, beat-to-beat blood pressure is calculated according to specific algorithms. | Less discomfort for the patient. Beat-to-beat blood pressure measurement. |
Incomplete validation. No ABPM possible. (Portapress not available on the market anymore) Used mainly for research purposes. |