Minimally Invasive Detection of a Sleep Apnoea

Study Overview
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Brief Summary
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Obstructive sleep apnoea (OSA) is characterised by recurrent nocturnal respiratory interruptions, resulting from the total or partial collapse of the upper respiratory ways. This results into sleep fragmentation, metabolic and biological disorders, which alter the neuropsychological and cardiovascular systems. Nowadays, 24% of men and 9% of women aged 30 to 60 years disclose already an asymptomatic and underdiagnosed sleep disorder breathing (SDB). In subjects suffering from cardiovascular disease, prevalence of SDB is higher than in the general population, reaching 87% in people with resistant hypertension, 51% in those with heart failure and 62% in those with atrial fibrillation (to cite a few).The current diagnostic tool for SDB is polysomnography (PSG), but this is an expensive, time-consuming and uncomfortable tool, which limits its wide-spread use despite the high frequency of SDB in general and, even more, in patients suffering from cardiovascular diseases. Several screening devices exist in order to test those patients at risk of SDB, but these have several limitations, since they are not recommended in patients who are asymptomatic for apnoea, in those with cardiorespiratory diseases, nocturnal arrhythmias or neurological and metabolic co-morbidities. In other words, nowadays there isn't an efficient screening tool of SDB, mainly for those with a low pre-test probability of having SDB. Preliminary evidence suggests that the seismocardiography (SCG) and the ballistocardiography (BCG) can detect nocturnal awakening and sleep disturbances with a good sensitivity and accuracy as compared to the state-of-the-art PSG. Simultaneous recording of SCG and BCG is called kinocardiography (KCG) and has not been performed yet during sleep. The main hypothesis tested in this study is that the KCG provides sensitive and accurate measures of obstructive and central apnoea as compared to the state-of-the-art PSG. The secondary hypotheses are related to modifications in the SCG and BCG signals during the apnoea and the effects of continuous positive air pressure (CPAP) therapy. These hypotheses will be tested through a series of studies in normal volunteers and patients, as follow: Group RESPIRATOIRYSIMUL (Study A): voluntary end-expiratory breathing cessations periods and obstructive voluntary apnoea's (n=46); Group SBD (Study B): patients admitted for complains of sleep disturbances without cardiovascular and/or respiratory abnormalities which could induce artifacts in the KCG recording (n=50); Group nCPAP (Study C): patients treated by nCPAP therapy (n=50); Group UNSELECTED (Study D): unselected consecutive patients (n=100), without recruitment restrictions. Study A is an interventional study on voluntary breath holding in normal volunteers. Studies B, C and D are observational investigations recruiting subjects referred for PSG as required by their medical condition. Because the KCG device is not intrusive, the investigators do not anticipate difficulties in the enrollment. This study will not affect in any manner the regular medical care of the patients admitted to the sleep laboratory. To conclude, SDB is a widespread disease with detrimental health effects and its prevalence is supposed to increase in future years. PSG is the gold standard for diagnosis of SDB but it is an expensive, uncomfortable and time-consuming tool, limiting its use in daily clinical practice. For subjects with a high pre-test probability of SDB, portable, inexpensive and easy-to-use tools have been proposed as sleep monitoring and seem to provide accurate estimates of SDB. Although such devices seem promising, they disclose also several limitations and are not universally accepted as SDB screening devices, mainly in case of low pre-test probability of SBD. The less cumbersome KCG may screen patients for SDB accurately. One of its unique features is also that it can directly identify the consequences of SDB and nCPAP therapy on the cardiovascular system, and in especially the presence of frequently associated cardiac arrhythmias. With a more efficient pre-screening, those who are most likely to be eligible for nCPAP therapy will have a better access to the currently existing sleep laboratory facilities. The present research project has thus the potential of improving SDB patients care and health, at no additional societal costs.

Official Title
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Minimally Invasive Detection of a Sleep Apnoea and Effects of nCPAP Therapy : a Proof-of-concept Study

Conditions
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Sleep Disorder; Breathing-Related, Cardiovascular Diseases, Cardiovascular Risk Factor, Cardiovascular Complication

Intervention / Treatment
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* Device: Kinocardiography unintrusive recording


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Men and women 18-70 years old Exclusion Criteria (group A): Cardiorespiratory co-morbidities Exclusion Criteria (groups B-C-D): BMI>35 kg/m2 Moderate, severe valvular disease Permanent atrial fibrillation or frequent premature contractions Atrio-ventricular conduction disturbances Medications which reduces heart rate and heart rate variability Cardiac rhythm driven by a pacemaker Systolic heart failure of any origin (ischaemic, dilatated ect..) Neurological diseases responsible for abnormal movements Denied participation

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Group RESPIRATORY SIMUL (Study A)<br>In 46 healthy subjects, a computer program will generate random instructions of periods of normal breathing, voluntary end-expiratory breathing cessation periods (as surrogate of central apnoea) and Muller's manœuvre (as surrogate of obstructive apnoea). Meanwhile, the KCG will record the parameters of biological interest. ECG, heart rate, beat to beat non-invasive blood pressure (Finometer), ventilation, end-tidal CO2 (AD instruments), O2 saturation (Nellcor), cardiac output (CO) (Philips) will also be recorded. | Device: Kinocardiography unintrusive recording<br>* The Kinocardiography (Kino) is a device which records the electric and mechanic function of the heart. The device comprises a combination of ECG recording, (6 degrees of freedom), accelerometer and gyroscope sensors. The Kino device consists of a back and a chest housing in contact with the patient. The back housing is placed in the middle of the lower back of the patient, and the chest housing is placed on the chest (either on the sternum or on the costal grill at the apex of the heart). The housings are connected by two cables. Data obtained from the device are visualized on a digital application via a Bluetooth connection. For the group A, the KCG records the cardiac signals while the patient performs specific respiratory manoevres, as describe above. For group B, C, D, the KCG records the cardiac contraction during sleep along with the PSG recording.<br>* Other names: For Group A, recording of the follow: heart rate, humeral blood pressure, oxygen saturation, respiratory rate, cutaneous pO2, pCO2, endtidalCO2,;|
| Group SDB (Study B)<br>In patients suspected of sleep apnoea and admitted to the sleep unit of the Erasme hospital to perform sleep test as required by their medical condition, the investigators will simultaneously record KCG and PSG and qualitatively compare the data (Bland-Altman plots). | Device: Kinocardiography unintrusive recording<br>* The Kinocardiography (Kino) is a device which records the electric and mechanic function of the heart. The device comprises a combination of ECG recording, (6 degrees of freedom), accelerometer and gyroscope sensors. The Kino device consists of a back and a chest housing in contact with the patient. The back housing is placed in the middle of the lower back of the patient, and the chest housing is placed on the chest (either on the sternum or on the costal grill at the apex of the heart). The housings are connected by two cables. Data obtained from the device are visualized on a digital application via a Bluetooth connection. For the group A, the KCG records the cardiac signals while the patient performs specific respiratory manoevres, as describe above. For group B, C, D, the KCG records the cardiac contraction during sleep along with the PSG recording.<br>* Other names: For Group A, recording of the follow: heart rate, humeral blood pressure, oxygen saturation, respiratory rate, cutaneous pO2, pCO2, endtidalCO2,;|
| Group nCPAP (Study C)<br>In patients with a diagnosis of sleep apnea, the investigators will determine if KCG is capable to reliably assess the efficacy of the nCPAP therapy in comparison to simultaneous PSG recording. Ongoing adjustment in the CPAP therapy pressure during the night, and its effect on cardiovascular haemodynamic assessed by the KCG, will be taken into account as well. | Device: Kinocardiography unintrusive recording<br>* The Kinocardiography (Kino) is a device which records the electric and mechanic function of the heart. The device comprises a combination of ECG recording, (6 degrees of freedom), accelerometer and gyroscope sensors. The Kino device consists of a back and a chest housing in contact with the patient. The back housing is placed in the middle of the lower back of the patient, and the chest housing is placed on the chest (either on the sternum or on the costal grill at the apex of the heart). The housings are connected by two cables. Data obtained from the device are visualized on a digital application via a Bluetooth connection. For the group A, the KCG records the cardiac signals while the patient performs specific respiratory manoevres, as describe above. For group B, C, D, the KCG records the cardiac contraction during sleep along with the PSG recording.<br>* Other names: For Group A, recording of the follow: heart rate, humeral blood pressure, oxygen saturation, respiratory rate, cutaneous pO2, pCO2, endtidalCO2,;|
| Group UNSELECTED (Study D)<br>After validation of the three previous steps, the investigators plan to extend the recordings on 100 unselected consecutive patients, without recruitment restrictions, which will undergo PSG recordings because of complains of sleep apnoea. | Device: Kinocardiography unintrusive recording<br>* The Kinocardiography (Kino) is a device which records the electric and mechanic function of the heart. The device comprises a combination of ECG recording, (6 degrees of freedom), accelerometer and gyroscope sensors. The Kino device consists of a back and a chest housing in contact with the patient. The back housing is placed in the middle of the lower back of the patient, and the chest housing is placed on the chest (either on the sternum or on the costal grill at the apex of the heart). The housings are connected by two cables. Data obtained from the device are visualized on a digital application via a Bluetooth connection. For the group A, the KCG records the cardiac signals while the patient performs specific respiratory manoevres, as describe above. For group B, C, D, the KCG records the cardiac contraction during sleep along with the PSG recording.<br>* Other names: For Group A, recording of the follow: heart rate, humeral blood pressure, oxygen saturation, respiratory rate, cutaneous pO2, pCO2, endtidalCO2,;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Group RESPIRATORY SIMUL (Study A) | The BCG and SCG kinetic energy (mJ) recorded with the KCG are profoundly affected by abnormal respiration, mainly by the Muller's manoeuvre. | Three months | 
| Group RESPIRATORY SIMUL (Study A) | The BCG and SCG kinetic energy changes are correlected with the changes of the intrathoracic pressure | Three months | 
| Group SDB (Study B) | The BCG and SCG signals are profoundly affected by the apnoea itself. The magnitude of these changes dépends on the severity of the underlying apnoea itself. | One year | 
| Group nCPAP (Study C) | The BCG and SCG signals are reversed to the Baseline in patients treated with nCPAP. | One year |