Measuring Breathing Airflow Using a Heat Sensitive Camera (ThermFlow)
Condition: Sleep Apnea
MeSH terms: Sleep Apnea Syndromes
Study type: Observational

Summary: 
      ThermPaed is a Sheffield Children's Hospital research collaborative which investigated the
      clinical diagnostic capabilities of high resolution thermal imaging (HRTI) in paediatrics.
      This research utilises thermal imaging techniques to detect fractures, arthritic inflammation
      and infection. ThermPaed proved HRTI has potential in paediatrics and resulted in development
      of techniques that has led to the current research study. The purpose of this study is to
      develop HRTI as a non-contact child-friendly means of measuring and monitoring paediatric
      airflow.

      Sheffield Children's Hospital Sleep Unit performs 500 sleep studies a year to investigate
      paediatric sleep-related breathing disorders. 1-6% of children have problems with their
      breathing during sleep and have breathing pauses called apnoeas. The condition needs accurate
      diagnosis and treatment to ensure correct blood oxygen levels. During a sleep study a number
      of physiological parameters are measured. These include heart rate, chest movements, airflow,
      oxygen levels, body position, snoring, movement and video. A total of 13 sensors are attached
      to the child whilst awake, and then the child settles to sleep. Airflow parameters are
      measured by two contact sensors; one measures airflow by temperature and the other measures
      airflow by pressure. Both sensors are placed in or very close to the nostrils to detect and
      classify apnoea. Due to their contact nature, these sensors are poorly tolerated. In a recent
      survey of 100 sleep studies on the sleep unit, 50% children did not allow the sensors to be
      attached or removed them immediately causing difficulties in interpreting their condition.

      Breathing generates changes in temperature around nose and mouth which can be detected with
      HRTI. The investigators will recruit 30 children who are undergoing a sleep study. The
      investigators will compare airflow measurements from the existing clinical nasal sensors and
      HRTI to evaluate whether this new technique will provide an accurate non-contact alternative
      to measure respiration airflow.
    

Detailed description: 
      The study will form part of a wider project currently ongoing which is looking into
      development of HRTI for clinical diagnosis and monitoring. It builds on the significant
      progress the investigators made through the ThermPaed study. Sheffield Hallam University
      supports this study by allocating an MPhil student (UR). The student will be jointly
      supervised at the University by Professor Saatchi who is well-established in digital signal
      and image processing and Professor Elphick and Dr Kingshott.

      This study design is explained below. Measurement of thermal imaging alongside standard
      clinical parameters Following ethics and HRA approval, the investigators will identify 30
      suitable children attending Sheffield Children's Hospital Sleep Unit who are undergoing
      cardiorespiratory PSG investigation for sleep-related breathing disorders.

      Each patient would undergo the standard diagnostic cardiorespiratory PSG and wear all the
      sensors as usual. In addition, following consent, HRTI will be performed in the Sleep Unit
      overnight. The HRTI device will be positioned alongside the standard video camera used in
      PSG. The standard recording time of a PSG study is between 8-12 hours and is determined by
      the child and their age-related sleep and wake times. Even if the child does not tolerate the
      nasal sensors, the investigators will record HRTI to identify potentially missed apnoea
      events. The study therefore does not interfere in any way with the patient's normal
      procedures.

      Patient, carer and staff opinions of the HRTI versus conventional nasal sensors.

      As part of the research, the participating children, their attending carer and overnight
      sleep nursing staff will complete an evaluation questionnaire [Appendix 1] in the morning
      following the PSG.

      Development of software to integrate the HRTI data with the PSG sleep system

      The HRTI data recording and processing will be carried out by the MPhil student, supervised
      by his university tutor. The data will be stored on a password secure laptop during the
      recording and then transferred and stored in a safe, secure and password protected drive at
      Sheffield Hallam University. Each participating patient will be assigned a unique identifying
      number (see sections 5.3 and 6.0). There will not be any identifiable patient information
      with these recordings. The PSG data are downloaded onto a sleep software system at the
      hospital and then the anonymised version of the airflow signals will be stored at Sheffield
      Hallam University research secure drive. This sleep software has the ability to export its
      data anonymously and so currently can be integrated alongside the HRTI data. Workflow on
      integrating these two sets of data will include:

        -  Discussion with the sleep software company to directly integrate the thermal imaging
           data into the sleep software.

        -  Time synchronising the two data sets. Blinded scoring analysis of the signals to compare
           apnoea event scoring and classification Once each child's data are collected, Dr
           Kingshott will interpret the PSG data to identify apnoea events. Following standard AASM
           scoring guidelines apnoeas will be marked using the nasal sensor channels versus the
           HRTI channel. In order to minimise scoring bias, the processing order for HRTI versus
           the data from the nasal sensors will be randomised.
    

Intervention name(s): Thermal Imaging camera
Intervention type(s): Device
Intervention description(s): Thermal Imaging camera used to measure respiratory flow.
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Children age 0-15.9 years Are attending the sleep unit for a cardiorespiratory sleep study
        to investigate or monitor sleep-disordered breathing