Validation of Structured Light Plethysmography (SLPvsPNT)

Validation of Structured Light Plethysmography Against Spirometry in Children and Adults

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.

Study Overview

• Status: Completed
• Conditions: Pulmonary Disease
• Intervention / Treatment: Device: Structured Light Plethysmography; Device: Pneumotachograph Spirometry

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Actual): 41
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Cambridgeshire
    • Cambridge, Cambridgeshire, United Kingdom, CB2 0QQ
      • Cambridge University Hospitals Foundation Trust

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 4 years to 78 years (Child, Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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)

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Breathing Sequence; 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; Non contact device that uses light to record displacement of the anterior thorax and abdomen region; Other Names: SLP; Device: Pneumotachograph Spirometry; Device that measures airflow at the mouth using a mouthpiece
Other: Agreement and repeatability Breathing Sequence; 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; Non contact device that uses light to record displacement of the anterior thorax and abdomen region; Other Names: SLP; Device: Pneumotachograph Spirometry; Device that measures airflow at the mouth using a mouthpiece

What is the study measuring?

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

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Inspiratory over Expiratory flow at 50 percent of tidal displacement (IE50) expressed at a ratio	Flow ratios derived from the Respiratory Waveforms	5 minutes

Collaborators and Investigators

• Sponsor: Pneumacare Ltd
• Collaborators: Cambridge University Hospitals NHS Foundation Trust; University of Cambridge
• Investigators: Principal Investigator: Karl Sylvester, PhD, Addenbrookes University Hospitals NHS Trust

Publications and helpful links

General Publications

• Stocks J, Godfrey S, Beardsmore C, Bar-Yishay E, Castile R; ERS/ATS Task Force on Standards for Infant Respiratory Function Testing. European Respiratory Society/American Thoracic Society. Plethysmographic measurements of lung volume and airway resistance. ERS/ATS Task Force on Standards for Infant Respiratory Function Testing. European Respiratory Society/ American Thoracic Society. Eur Respir J. 2001 Feb;17(2):302-12. doi: 10.1183/09031936.01.17203020.
• Bates JH, Schmalisch G, Filbrun D, Stocks J. Tidal breath analysis for infant pulmonary function testing. ERS/ATS Task Force on Standards for Infant Respiratory Function Testing. European Respiratory Society/American Thoracic Society. Eur Respir J. 2000 Dec;16(6):1180-92. doi: 10.1034/j.1399-3003.2000.16f26.x.
• Ferrigno G, Carnevali P, Aliverti A, Molteni F, Beulcke G, Pedotti A. Three-dimensional optical analysis of chest wall motion. J Appl Physiol (1985). 1994 Sep;77(3):1224-31. doi: 10.1152/jappl.1994.77.3.1224.
• Cala SJ, Kenyon CM, Ferrigno G, Carnevali P, Aliverti A, Pedotti A, Macklem PT, Rochester DF. Chest wall and lung volume estimation by optical reflectance motion analysis. J Appl Physiol (1985). 1996 Dec;81(6):2680-9. doi: 10.1152/jappl.1996.81.6.2680.

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2011
• Primary Completion (Actual): January 1, 2017
• Study Completion (Actual): September 1, 2017

Study Registration Dates

• First Submitted: November 3, 2015
• First Submitted That Met QC Criteria: November 3, 2015
• First Posted (Estimate): November 5, 2015

Study Record Updates

• Last Update Posted (Actual): July 10, 2018
• Last Update Submitted That Met QC Criteria: July 7, 2018
• Last Verified: July 1, 2018

More Information

Terms related to this study

• Keywords: Spirometry; Structured Light Plethysmography; Pneumotachograph
• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Lung Diseases
• Other Study ID Numbers: CIP01/0010