Methods for Detecting Abnormal Ventilation in Children - the Case Study of 13-Years old Pitt-Hopkins Girl

Abstract

We present contactless technology measuring abnormal ventilation and compare it with polysomnography (PSG). A 13-years old girl with Pitt-Hopkins syndrome presented hyperpnoea periods with apneic spells. The PSG was conducted simultaneously with Emfit movement sensor (Emfit, Finland) and video camera with depth sensor (NEL, Finland). The respiratory efforts from PSG, Emfit sensor, and NEL were compared. In addition, we measured daytime breathing with tracheal microphone (PneaVox,France). The aim was to deepen the knowledge of daytime hyperpnoea periods and ensure that no upper airway obstruction was present during sleep. The signs of upper airway obstruction were not detected despite of minor sleep time. Monitoring respiratory effort with PSG is demanding in all patient groups. The used unobtrusive methods were capable to reveal breathing frequency and hyperpnoea periods. Every day diagnostics need technology like this for monitoring vital signs at hospital wards and at home from subjects with disabilities and co-operation difficulties.

Keywords: Emfit sensor; NEL seizure detection; Pitt-Hopkins; respiratory effort; sleep; sleep-disordered breathing.

Figure 1.

Polysomnography acquisition was done with external devices. (a) ‘A little patient’ with extended PSG equipment and accessories. (b) Emfit mattress sheet which can be connected to Embla N7000 bedside unit via bipolar inputs. The grey Cidelec CID-Lxe device with PneaVoX sound sensor lay on the bed. (c) Depth sensor station NEL. (d) Emfit sensor is placed under a foam mattress and subject's thoracic area.

Figure 2.

Screenshot (5 min) of daytime Cidelec analysis software showing the hyperbreathing periods emphasized in Airflow channel (4 periods, one with red square). Long apneas occurs between those gasping periods (light blue square). Suprasternal pressure signal measured with tracheal microphone was used to calculate respiratory effort. The Ei/Ee trace visualize that expiration (Ee blue color, down) is emphasized over inspiration (Ei red color, upfords) during hyperpnoea. In addition, the increased breathing efforts are seen in Emfit mattress sensor.

Figure 3.

The amount of sleep in the laboratory night was minor and there was no REM sleep at all.

Figure 4.

Wakefulness period (4 min) in nighttime polysomnography showing the hyperpnoea periods (red circles) followed by apneic spells. EtCo2 was measured by capnometry. Airflow was measured from the nasal pressure sensor. Breathing movements were detected by inductive belt traces (Abd and Thx moves) and by Emfit mattress (Emfit resp). Breathing efforts were measured by surface EMG electrodes from abdomen and diaphragm muscles (EMG abd, EMG diag). Emfit channel with filtration 6–16 Hz shows the typical spiking phenomenon implying increased respiratory effort.

Figure 5.

Hyperpnoea periods analyzed from conventional PSG (Flow and RIP), video and depth sensor (NEL) and Emfit mattress. Hyperpnoea periods and following apneas are revealed by all sensors. Flow  =  airflow by nasal prongs, RIP  =  respiratory belt, NEL  =  video and depth sensor, Emfit  =  Emfit mattress signal.