title: Contactless respiration rate measurement using optical method and empirical mode decomposition.
abstract: BACKGROUND
  At the emergency triage center, assessment of the present of the danger signs and measurement of vital signs are measured according to the guidelines. The respiration rate is still posing a challenge to the doctor as it is impractical to use conventional devices. Attaching measurement devices to the patient will induce artificial measurements (self-awareness stress effects) besides being time-consuming. Currently, the medical officers visually count the number of times the chest movement in a minute, sometimes poses cultural challenges especially for female patients.
  
  
  OBJECTIVE
  The main objective of this paper is to develop a robust algorithm to extract respiration rate using the contactless displacement sensor.
  
  
  METHODS
  In this study, chest movements were used as an indicative of inspiration and expiration to measure respiratory rate using the contactless displacement sensor. The contactless optical signals were recorded from 32 healthy subjects in four different controlled breathing conditions: rest, coughing, talking and hand movement to obtain the motion artifacts that the patients may have in the emergency department. The Empirical mode decomposition (EMD) algorithm was used to derive continuous RR signal from the contactless optical signal.
  
  
  RESULTS
  The analysis showed that there is a good correlation (0.9702) with RMSE of 0.33 breaths per minutes between the contact respiration rate and contactless respiration rate using empirical mode decomposition method.
  
  
  CONCLUSIONS
  It can be concluded that the empirical mode decomposition method can extract the respiration rate of the contactless optical signal from chest movement.
authors.affiliation: Department of Electrical, Electronic and Systems Engineering, Universiti Kebangsaan Malaysia, Selangor, Malaysia.
authors.forename: K B
authors.initials: KB
authors.lastname: Gan
authors.affiliation: Department of Electrical, Electronic and Systems Engineering, Universiti Kebangsaan Malaysia, Selangor, Malaysia.
authors.forename: E S
authors.initials: ES
authors.lastname: Yahyavi
authors.affiliation: Department of Emergency Medicine, UKM Medical Centre Jalan Yaacob Latif, Kuala Lumpur, Malaysia.
authors.forename: M S
authors.initials: MS
authors.lastname: Ismail
mesh_terms: D000328:Adult; D000465:Algorithms; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D007834:Lasers; D008297:Male; D008875:Middle Aged; D012129:Respiratory Function Tests / Q000295:instrumentation*; D056152:Respiratory Rate / Q000502:physiology*; D013909:Thorax / Q000502:physiology*
keywords: Contactless; displacement; empirical mode decomposition; respiration rate; triage