C. L. Parsley

Publications (4)0 Total impact

• Conference Proceeding: Detection of Central Respiratory Events Using Pulse Transit Time in Infants

  J.Y.A. Foo, C.L. Parsley, S.J. Wilson, G.R. Williams, M. Harris, D.M. Cooper
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  ABSTRACT: The prevalence of sudden infant death syndrome (SIDS) has been well studied and central sleep apnea is deemed as one of the possible causes. Current gold standard for its diagnosis is nocturnal polysomnography (PSG). However, this procedure is complex and generally needs to be performed in a sleep laboratory. Pulse transit time (PTT) shows its potential to indicate abrupt blood pressure (BP) changes during the occurrences of upper airway obstruction. The main objective of this study was to assess the capability of PTT to differentiate central respiratory events from tidal breathing in infants. This study involved 5 infants (4 male) with mean age of 7.8 months. 50 valid central respiratory events were randomly selected. These events were free from motion artifacts and pre-scored in the corresponding PSG studies by two blinded observers. PTT measurements from these events were then evaluated against the PSG scorings. Using a two-tailed F-test for variance, it was observed that central events differed from tidal breathing in a significant manner (p<0.05). Furthermore, PTT has showed its sensitivity to monitor marginal BP fluctuations during tidal breathing. Hence, the results herein suggest that PTT can be a valuable non-invasive technique to monitor central apneic events in sleeping infants
  Engineering in Medicine and Biology Society, 2005. IEEE-EMBS 2005. 27th Annual International Conference of the; 02/2006
• Conference Proceeding: Relations between Physiologic Parameters and Pulse Transit Time during Loaded Breathing

  J.Y.A. Foo, C.L. Parsley, S.J. Wilson, G.R. Williams, M. Harris, D.M. Cooper
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  ABSTRACT: Pulse transit time (PTT) is a non-invasive measure, defined as time taken for the pulse pressure waves to travel from the R-wave of electrocardiogram to a selected peripheral site. Baseline PTT value is known to be influenced by physiologic variables like heart rate (HR), blood pressure (BP) and arterial compliance (AC). However, few quantitative data are available describing the factors which can influence PTT measurements in a child during breathing. The aim of this study was to investigate the effects of changes in breathing efforts on PTT baseline and fluctuations. Two different inspiratory resistive loading (IRL) devices were used to simulate loaded breathing in order to induce these effects. It is known that HR can influence the normative PTT value however the effect of HR variability (HRV) is not well-studied. Two groups of 3 healthy children (les12years) were recruited; one group with insignificant (p?>0.05) HR changes during all test activities. Results showed that HRV is not the sole contributor to PTT variations and suggest that changes in other physiologic parameters are also equally important. Hence, monitoring PTT measurement can be indicative of these associated changes during tidal or increased breathing efforts in healthy children
  Engineering in Medicine and Biology Society, 2005. IEEE-EMBS 2005. 27th Annual International Conference of the; 02/2006
• Article: Detection of central respiratory events using pulse transit time in infants

  J. Y. A. Foo, C. L. Parsley, S J Wilson, G R Williams, M Harris, D M Cooper
• Article: Relations between physiologic parameters and pulse transit time during loaded breathing

  J. Y. A. Foo, C. L. Parsley, S J Wilson, G R Williams, M Harris, D M Cooper