title: Long-term recording and automatic analysis of cough using filtered acoustic signals and movements on static charge sensitive bed.
abstract: Reliable long-term assessment of cough is necessary in many clinical and scientific settings. A new method for long-term recording and automatic analysis of cough is presented. The method is based on simultaneous recording of two independent signals: high-pass filtered cough sounds and cough-induced fast movements of the body. The acoustic signals are recorded with a dynamic microphone in the acoustic focus of a glass fiber paraboloid mirror. Body movements are recorded with a static charge-sensitive bed located under an ordinary plastic foam mattress. The patient can be studied lying or sitting with no transducers or electrodes attached. A microcomputer is used for sampling of signals, detection of cough, statistical analyses, and on-line printing of results. The method was validated in seven adult patients with a total of 809 spontaneous cough events, using clinical observation as a reference. The sensitivity of the method to detect cough was 99.0 percent, and the positive predictivity was 98.1 percent. The system ignored speaking and snoring. The method provides a convenient means of reliable long-term follow-up of cough in clinical work and research.
authors.affiliation: Department of Neurology, Helsinki University Central Hospital, Finland.
authors.forename: T
authors.initials: T
authors.lastname: Salmi
authors.forename: A R
authors.initials: AR
authors.lastname: Sovijärvi
authors.forename: P
authors.initials: P
authors.lastname: Brander
authors.forename: P
authors.initials: P
authors.lastname: Piirilä
mesh_terms: D000162:Acoustics / Q000295:instrumentation; D000328:Adult; D001991:Bronchitis / Q000150:complications; D002908:Chronic Disease; D003371:Cough / Q000175:diagnosis* / Q000209:etiology; D005260:Female; D005374:Filtration; D006801:Humans; D008838:Microcomputers; D008875:Middle Aged; D009068:Movement; D011187:Posture; D012815:Signal Processing, Computer-Assisted