Gastrointestinal motility during sleep assessed by tracking of telemetric capsules combined with polysomnography – a pilot study

Figures & data

Figure 1 The 3D-Transit system

Notes: (A) Capsule containing an electromagnet and a battery (inset). The abdominal belt contains the 3D-Transit receiver and is worn by the subjects throughout the examination. Thoracic belt (blue) and an accelerometer inside the detector record artifacts owing to breathing and posture changes. The ruler is measuring in centimeters. (B) 3D-Transit visualization and analysis software. Changes in position and orientation of the capsules with respect to the receiver reflect gastrointestinal contractile activity and progression. Coordinates x, y, and z display capsule movements in a frontal, sagittal, and transversal plane, respectively. The Φ,θ coordinates describe capsule rotation, reflecting the contraction frequency (arrows mark individual contractions). The inset shows the actual movement of the capsule, which corresponds to the changes in the coordinates. The x-axis represents time.
Abbreviations: R, respiration; sec, seconds.

Figure 2 Data synchronization.

Notes: Posture changes obtained through the accelerometer inside the 3D-Transit receiver (red, green, and blue lines) are associated with an increased heart rate achieved through the portable sleep monitor. This way data were easily time-linked (ovals).

Table 1 Sleep distribution and efficiency

ID	N1 (min)	N1 (%)	N2 (min)	N2 (%)	N3 (min)	N3 (%)	REM (min)	REM (%)	SE (%)	WASO (min)	TST (min)	Arousals	Arousal index
1	13.5	3.4	208	52.3	83	20.9	93	23.4	37.7	84	397.5	50	7.5
2	14	3.1	249.5	55.6	66.5	14.8	118.5	26.4	96	14.5	448.5	37	5.0
3	15	4.1	200	54.7	51.5	14.1	99	27.1	89.4	12.5	365.5	34	5.6
4	11.5	3.7	156.5	50.8	67.5	21.9	72.5	23.5	78.6	7	308	87	16.9
5	17.5	4.8	173.5	47.5	55	15	119.5	32.7	71.1	29	365.5	51	8.4
6	22	5.4	189	46.8	88	21.8	105	26	39	27	404	62	9.2
7	15	5	176.5	58.5	31.5	10.4	78.5	26	67.5	38.5	301.5	73	14.5
Β	12.5	3	205.5	49.5	77.5	18.7	119.5	28.8	95.7	16.5	415	39	5.6
9	15	4.4	175.5	51.5	56.5	16.7	93	27.4	90.5	26	339	43	7.6
Median	15	4.1	189	51.5	66.5	16.7	99	26.4	78.6	26	365.5	50	8.2
Range	11.5–15	3–5.4	156.5–249.5	46.0–58.5	31.5–88	10.4–21.9	72.5–119.5	23.4–32.7	37.7–96	7–84	301.5–448.5	34–87	5.0–16.9

Abbreviations: N1, drowsiness; min, minutes; N2, light sleep; N3, slow wave (deep) sleep; REM, rapid eye movement; SE, sleep efficiency (total sleep time/time in bed ×100); WASO, wake after sleep onset; TST, total sleep time; Arousal index, arousals per hour sleep; ID, identification.

Table 2 Gastric contractions and basal colonic activity during sleep and nocturnal awakenings

Sleep stage	Gastric contractions (contractions per min) (median; range)	P-value	Gastric contractions (amplitude, mm) (median; range)	P-value	Colonic activity (mean SD, mm) (median; range)	P-value
N1	2.8 (2.4–3.3)	NS*	2.5 (1.4–8.6)	0.03*	1.40 (0.5–10.4)	NS*
				0.05**		<0.0001**
N2	2.6 (2.2–3.8)	<0.0001*	2.7 (0.8–9.6)	0.0006*	1.15 (0.3–14.5)	<0.0001*
				<0.0001**		<0.0001**
N3	2.8 (2.2–3.5)	NS*	2.0 (0.2–8.5)	<0.001*	0.88 (0.3–12.1)	<0.0001*
REM	2.6 (2.4–3.1)	<0.0001*	2.7 (1.2–5.5)	<0.0001*	1.59 (0.5–19.2)	NS*
				0.009**		<0.0001**
Wake	2.9 (2.2–3.4)	–	5.1 (1.3–9.7)	–	1.69 (0.5–13.5)	–

Notes:

* Sleep stage compared with nocturnal wake period;

** N3 compared with other sleep stages.

Abbreviations: min, minutes; N1, drowsiness; NS, not significant; N2, light sleep; N3, slow wave (deep) sleep; REM, rapid eye movement; Wake, wake periods.