title: Piezoresistive Membrane Surface Stress Sensors for Characterization of Breath Samples of Head and Neck Cancer Patients.
abstract: For many diseases, where a particular organ is affected, chemical by-products can be found in the patient's exhaled breath. Breath analysis is often done using gas chromatography and mass spectrometry, but interpretation of results is difficult and time-consuming. We performed characterization of patients' exhaled breath samples by an electronic nose technique based on an array of nanomechanical membrane sensors. Each membrane is coated with a different thin polymer layer. By pumping the exhaled breath into a measurement chamber, volatile organic compounds present in patients' breath diffuse into the polymer layers and deform the membranes by changes in surface stress. The bending of the membranes is measured piezoresistively and the signals are converted into voltages. The sensor deflection pattern allows one to characterize the condition of the patient. In a clinical pilot study, we investigated breath samples from head and neck cancer patients and healthy control persons. Evaluation using principal component analysis (PCA) allowed a clear distinction between the two groups. As head and neck cancer can be completely removed by surgery, the breath of cured patients was investigated after surgery again and the results were similar to those of the healthy control group, indicating that surgery was successful.
authors.affiliation: Department of Physics, University of Basel, Swiss Nanoscience Institute, Klingelbergstrasse 82, CH-4056 Basel, Switzerland. Hans-Peter.Lang@unibas.ch.
authors.forename: Hans Peter
authors.initials: HP
authors.lastname: Lang
authors.affiliation: SAMLAB, EPFL Neuch&#226;tel, CH-2002 Neuch&#226;tel, Switzerland. frederic.loizeau@sensirion.com.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Loizeau
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, CHUV, University of Lausanne, CH-1015 Lausanne, Switzerland. Agnes.Hiou@chuv.ch.
authors.forename: Agnès
authors.initials: A
authors.lastname: Hiou-Feige
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, CHUV, University of Lausanne, CH-1015 Lausanne, Switzerland. Jean-Paul.Rivals@chuv.ch.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Rivals
authors.affiliation: Ludwig Cancer Research Center, Department of Fundamental Oncology, Faculty of Biology and Medicine, University of Lausanne, CH-1066 Epalinges, Switzerland. Pedro.Romero@hospvd.ch.
authors.forename: Pedro
authors.initials: P
authors.lastname: Romero
authors.affiliation: SAMLAB, EPFL Neuch&#226;tel, CH-2002 Neuch&#226;tel, Switzerland. akiyama@nanoworld.com.
authors.forename: Terunobu
authors.initials: T
authors.lastname: Akiyama
authors.affiliation: Department of Physics, University of Basel, Swiss Nanoscience Institute, Klingelbergstrasse 82, CH-4056 Basel, Switzerland. Christoph.Gerber@unibas.ch.
authors.forename: Christoph
authors.initials: C
authors.lastname: Gerber
authors.affiliation: Department of Physics, University of Basel, Swiss Nanoscience Institute, Klingelbergstrasse 82, CH-4056 Basel, Switzerland. Ernst.Meyer@unibas.ch.
authors.forename: Ernst
authors.initials: E
authors.lastname: Meyer
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015374:Biosensing Techniques / Q000379:methods*; D001944:Breath Tests; D005260:Female; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D025341:Principal Component Analysis
keywords: breath analysis; electronic nose; head and neck cancer; nanomechanical sensor; piezoresistive membrane sensors; surface stress sensor