Table 3.

List of the most important features of the tilt tables with combined LBNP chambers shown in the literature and the main results of research works carried out with them.

Features			Subjects; experimental procedure; main outcome	Reference
Tilt table	LBNP chamber	Biomedical monitoring
Manually adjustable in the range from −15° to + 60° with 10° increment, steel frame, adjustable right-armrest, adjustable footplate	Manually adjustable down to −60 mmHg, high power vacuum cleaner, plastic and wooden elements, neoprene waist seal	ECG, blood pressure, brachial and cerebral blood flow, end-tidal tensions of oxygen (PETO2) and carbon dioxide (PETCO2)	No information on number of subjects; 20-minute supine rest, 20-minute 60° HUT at 30-second transition to upright, 3 sequences of 10-minute HUTs and LBNP at −20, −40 and −60 mmHg, respectively, recovery; suggestion that tilt testing with combined LBNP can be considered as a “gold standard”	Protheroe et al.36
Manually adjustable in the range from −90° to + 90°, steel frame	Manually adjustable down to −50 mmHg, industrial 6-horsepower vacuum, wooden box, kayak spray skirt	ECG, HR, blood pressure, MAP, SV, CO, PETCO2, transcranial Doppler, cerebral blood velocity (CBV)	13 subjects (males); 5-minute supine rest, 10-minute −50 mmHg supine LBNP, 15-minute recovery, 10-minute 45° HDT or −45° HUT and −50 mmHg LBNP, recovery; body position has no effect on CBV responses during LBNP, CBV decreases during LBNP	Tymko et al.39
Manually adjustable in the range from 0° to −15°, steel frame	Manually adjustable down to −25 mmHg, industrial vacuum pump, steel and Plexiglas elements, neoprene seal	Photoplethysmography, tibial and skin blood flows, NIRS	11 subjects (8 males and 3 females); 5-minute sitting on the tilt table, 5-minute supine rest, 5-minute −15° HDT, 10-minute −15° HDT and −25 mmHg LBNP; short-term LBNP can reduce the HDT-induced increase in microvascular blood flow in the tibia to values consistent with sitting posture	Siamwala et al.40
Automatically adjustable in the range from −70° to + 70°, table attached to the movable steel rim, adjustable footplate	Automatically adjustable down to −60 mmHg by an advanced subsystem for generating underpressure, steel and Plexiglas elements, neoprene seal	ECG, HR, blood pressure, MAP, SBP, DBP, impedance cardiography, SV	15 subjects (males); 30-minute supine rest, 5-minute 70° HUT followed by additional 20 mmHg LBNP that is increased by additional 10 mmHg LBNP every three minutes until presyncope occurred; mean standing time from begin HUT to presyncope was determined	Grasser et al.42
Automatically adjustable in the range from −45° to + 80° with up to 45°/s rate of tilt changes, steel frame, adjustable handrest, adjustable footboard	Automatically adjustable down to −100 mmHg with up to 20 mmHg/s rate of underpressure changes, Al and Plexiglas elements, neoprene waist seal	ECG, HR, IBI, blood pressure, MAP, SBP, DBP, SV, CO, LVET, RPP, TPR, pulse oximetry, EMG, SCL, body temperature, impedance reography, EEG, respiration curve, NIRS	17 subjects (14 males and 3 females); 5-minute supine rest, −100 mmHg supine LBNP, 75° HUT, −60 mmHg LBNP associated with 75° HUT, separated by 3-minute resting phases; recovery; the prototype system can map any pre-programed tilt and LBNP profiles, confirmation of the efficiency of performing experimental procedures	Dziuda et al.