Table 2.
Technologies available for continuous monitoring on the general hospital ward
| Device | Vital signs | Technology | Transducer | Sampling location | Connectivity | Ergonomicsa |
| Pulse oximeter | SpO2, HR, RR | Photoplethysmograpy | (1) Transmittance(2) Reflectance | (1) Digit, ear, nasal alae(2) Forehead, chest | (3) Not attached(4) Wireless (Bluetooth, WiFi) | (3) B(4) A− |
| Capnograph | ETCO2, RR | IR spectography | Nasal cannula | Mouth/nose | Attached | C |
| Airflow detector | RR | Humidity detector, thermistor | Face mask, nasal transducer | Mouth/nose | Attached | C |
| Impedance plethysmography | RR, tidal volume | Transthoracic impedance | Electrodes, strain gauges | Chest wall | Attached | B |
| Bioacoustics | RR | Large airway audio (breath) detection | Microphone | Neck | Attached | B |
| Piezoelectric | HR, RR | Piezoelectrics | Piezoelectric element | Under mattress | Hardwired to mattress | A |
| cNIBP | SBP, DBP, MBP | Pulse transit time | Photoplethysmograph, electrodes | Wrist | Wireless | A− |
| Patch (Wearable) | ECG, RR, HR | Accelerometry, electrical impedance | Accelerometer, electrodes | Chest wall | Wireless (Bluetooth, WiFi) | A |
cNIBP, continuous noninvasive blood pressure; ETCO2, end-tidal CO2; HR, heart rate; RR, respiratory rate.
a(A) High patient acceptance due to small transducer not attached to bedside device. (B) Larger transducer (± adhesive) attached to bedside device. (C) Facial transducer often encumbering for awake patients and attached to bedside device.