Validation of Structured Light Plethysmography

Study Overview
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Brief Summary
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Measurements of Structured Light Plethysmography (SLP) using a chest wall movement based method will be compared to those obtained by spirometry using a flow based pneumotachograph method. This study will enable validation of SLP in children and adults by allowing direct comparison of simultaneous measurements of breathing sequences using the two measurement techniques. The investigators will also examine, in a group of normal adults, repeatability of the agreement between the two devices, and whether the agreement is affected by a change in tidal breathing parameters.

Detailed Description
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Measurements using the Structured Light Plethysmography method will be compared to those obtained by spirometry using a flow based pneumotachograph. Spirometry is the gold standard for measuring lung function in both clinical support and research roles. Modern spirometers are high precision, reliable instruments enabling a large numbers of parameters relating to lung volumes and the rate of emptying the lungs during a forced expiration to be measured. The most common and accurate method to measure the patient's forced expiration is via pneumotachograph which measures the flow of air through a mouthpiece and integrates the signal to derive the volume expired. Structured Light Plethysmography (SLP) system that measures changes of the chest and abdominal wall movement during breathing by modelling the thorax and abdominal surface defined by a projected structured light pattern which enables a grid of virtual parts to be formed, the movement of which is recorded by digital cameras. SLP provides non-contact assessment to provide lung function data utilising structured light technologies and enhanced imaging processing. In this study direct comparison will be made of measurements recorded simultaneously using the two measuring devices in children and adults. To examine repeatability of the agreement between tidal breathing parameters measured by two techniques, repeated measurements will be performed in each of a group of normal adult subjects. The investigators will also examine whether the agreement is affected by a change in tidal breathing parameters. To obtain a change in tidal breathing parameters, measurements will be recorded during resting spontaneous breathing and after a period of exercise to elevate Respiratory Rate.

Official Title
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Validation of Structured Light Plethysmography Against Spirometry in Children and Adults

Conditions
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Pulmonary Disease

Intervention / Treatment
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* Device: Structured Light Plethysmography
* Device: Pneumotachograph Spirometry


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: For the patient group, any patient attending the outpatient department or the Lung Function Laboratory For the Healthy Normals group, any adult between 18 and 80 years with no current or previous respiratory condition. Exclusion Criteria: A current cold or other viral infection chest surgery within 4 weeks Haemoptysis of unknown origin the (forced expiratory manoeuvre may aggravate the underlying condition) Pneumothorax Unstable respiratory or cardiovascular status (forced expiratory manoeuvre may worsen angina or cause changes in blood pressure) or recent myocardial infarction or pulmonary embolus Recent eye surgery Presence of an acute disease process that might interfere with test performance (e.g. Nausea, vomiting)

Ages Eligible for Study
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Minimum Age: 6 Years
Maximum Age: 80 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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Design Details

Primary Purpose: Supportive Care
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Breathing Sequence<br>Simultaneous measurement using Structured Light Plethysmography and Pneumotachograph Spirometry during a period of tidal breathing followed by a forced respiratory manoeuvre. This sequence is repeated twice. | Device: Structured Light Plethysmography<br>* Non contact device that uses light to record displacement of the anterior thorax and abdomen region<br>* Other names: SLP;Device: Pneumotachograph Spirometry<br>* Device that measures airflow at the mouth using a mouthpiece<br>|
| Other: Agreement and repeatability Breathing Sequence<br>Simultaneous measurement using Structured Light Plethysmography and Pneumotachograph Spirometry during a period of tidal breathing. This sequence is repeated one further time at rest, and once further time after an exercise test to elevate respiratory rate. | Device: Structured Light Plethysmography<br>* Non contact device that uses light to record displacement of the anterior thorax and abdomen region<br>* Other names: SLP;Device: Pneumotachograph Spirometry<br>* Device that measures airflow at the mouth using a mouthpiece<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Forced Vital Capacity (FVC) measured in Litres | The volume of air a person can exhale during a maximal forced breath | 5 minutes | 
| Forced Expiratory Volume in one second (FEV1) measured in litres per second | The volume of air a person can exhale in one second during a maximal forced breath | 5 minutes | 
| Peak Expiratory Flow (PEF) measured in litres per second | The maximal flow a person can achieve during a maximal forced breath | 5 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Respiratory Waveform | Visual comparison of respiratory waveform shape and amplitude produced by pneumotachograph and SLP. | 5 minutes | 
| Respiratory Rate (RR) measured in seconds | Tmings derived from the Respiratory Waveforms | 5 minutes | 
| Inspiratory Time (tI) measured in seconds | Timings derived from the Respiratory Waveforms | 5 minutes | 
| Expiratory Time (tE) measured in seconds | Timings derived from the Respiratory Waveforms | 5 minutes | 
| Total breath time (tTot) measured in seconds | Timings derived from the Respiratory Waveforms | 5 minutes | 
| Inspiratory/expiratory ratio (tI/tE) expressed as a ratio | Timing ratios derived from the Respiratory Waveforms | 5 minutes | 
| The duty cycle (tI/tTot) expressed as a ratio | Timing ratios derived from the Respiratory Waveforms | 5 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Structured Light Plethysmography, Spirometry, Pneumotachograph