Work of breathing in exercise and disease

  • Tom Powell

    Student thesis: Doctoral Thesis


    This thesis is focussed on developing new methods and outcomes to assess respiratory function that require little or no volitional effort on behalf of the participants being tested. Specifically to attempt to detach the behaviour of the patient from the accuracy of the test of respiratory function, resulting in techniques that are simpler and easier to administer and undertake for both assessor and participant. It aims to develop methods that reduce the involvement of the participant during assessment of respiratory function. The human body’s way of controlling respiration has evolved into a sophisticated system that optimises breathing pattern to maintain the most efficient homeostatic action of the respiratory system. Eliciting and assessing this automatic response is the key to removing the action of participation from respiratory functiontesting. The focus must therefore be on developing non-invasive, sub-maximal techniques that allow participants to enter into a steady state of respiration and how this can be assessed. Two techniques were investigated; Respiratory Endurance (as the inspiratory work of breathing) and Tidal Breathing Flow Profile, and these were successfully applied in 99 adult participants (68 healthy controls and 31 COPD patients) and 75 children (48 clinical group and 27 healthy controls) who completed 467 respiratory endurance trials whilst seated and exercising, and 249 relaxed tidal breathing trials. The difficulties with lung function assessment are well established and have been described in this thesis. Much recent emphasis has been put on developing existing devices and protocols rather than developing new techniques and approaching these difficulties from alternative viewpoints. This thesis has described the development of innovative techniques to assess the function of the respiratory systems that aim to overcome the issues associated with maximal testing. It was shown that these techniques are easy to undertake for a range of participants, simple to analyse and are able to reliably differentiate between health and disease, suggesting that they could become a useful adjunct to existing methods of respiratory assessment.
    Date of Award2010
    Original languageEnglish


    • Respiratory organs
    • Respiration

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