title: An enhanced sensing application based on a flexible projected capacitive-sensing mattress.
abstract: This paper presents a cost-effective sensor system for mattresses that can classify the sleeping posture of an individual and prevent pressure ulcers. This system applies projected capacitive sensing to the field of health care. The charge time (CT) method was used to sensitively and accurately measure the capacitance of the projected electrodes. The required characteristics of the projected capacitor were identified to develop large-area applications for sensory mattresses. The area of the electrodes, the use of shielding, and the increased length of the transmission line were calibrated to more accurately measure the capacitance of the electrodes in large-size applications. To offer the users comfort in the prone position, a flexible substrate was selected and covered with 16 × 20 electrodes. Compared with the static charge sensitive bed (SCSB), our proposed system-flexible projected capacitive-sensing mattress (FPCSM) comes with more electrodes to increase the resolution of posture identification. As for the body pressure system (BPS), the FPCSM has advantages such as lower cost, higher aging-resistance capability, and the ability to sense the capacitance of the covered regions without physical contact. The proposed guard ring design effectively absorbs the noise and interrupts leakage paths. The projected capacitive electrode is suitable for proximity-sensing applications and succeeds at quickly recognizing the sleeping pattern of the user.
authors.affiliation: Department of Electrical Engineering, National Cheng-Kung University, Tainan 701, Taiwan. ee78350526@gmail.com.
authors.forename: Wen-Ying
authors.initials: WY
authors.lastname: Chang
authors.affiliation: Department of Electrical Engineering, National Cheng-Kung University, Tainan 701, Taiwan. chichun19771007@gmail.com.
authors.forename: Chi-Chun
authors.initials: CC
authors.lastname: Chen
authors.affiliation: Department of Pulmonary Medicine, Taipei Medical University Shuang-Ho Hospital, Taipei 235, Taiwan. 09005@s.tmu.edu.tw.
authors.forename: Chih-Cheng
authors.initials: CC
authors.lastname: Chang
authors.affiliation: Department of Electrical Engineering, National Cheng-Kung University, Tainan 701, Taiwan. cyang@mail.ncku.edu.tw.
authors.forename: Chin-Lung
authors.initials: CL
authors.lastname: Yang
mesh_terms: D001513:Beds; D025802:Electric Capacitance; D004566:Electrodes; D006801:Humans; D011312:Pressure; D058998:Remote Sensing Technology / Q000379:methods*; D016683:Supine Position; D013997:Time Factors
references.citation: IEEE J Biomed Health Inform. 2013 Nov;17(6):985-93
references.pmid: 24240716
references.citation: Sensors (Basel). 2011;11(6):6037-55
references.pmid: 22163941
references.citation: IEEE Trans Biomed Eng. 2002 Sep;49(9):936-42
references.pmid: 12214883
references.citation: Respir Physiol Neurobiol. 2013 Jun 15;187(2):183-9
references.pmid: 23583829
references.citation: Conf Proc IEEE Eng Med Biol Soc. 2005;2005:6437-40
references.pmid: 17281742
references.citation: Sensors (Basel). 2013 Dec 31;14(1):510-31
references.pmid: 24385029
references.citation: Clin Physiol. 1996 Jan;16(1):23-30
references.pmid: 8867774
references.citation: J Adv Nurs. 2009 Apr;65(4):809-17
references.pmid: 19228239
references.citation: Physiol Meas. 1995 Aug;16(3):161-7
references.pmid: 7488976
references.citation: Int J Med Inform. 2011 Feb;80(2):127-32
references.pmid: 21051278
references.citation: IEEE Trans Biomed Eng. 2005 Dec;52(12):2100-7
references.pmid: 16366233
references.citation: Annu Int Conf IEEE Eng Med Biol Soc. 2009;2009:6131-4
references.pmid: 19965072
references.citation: IEEE Trans Inf Technol Biomed. 2010 Jan;14(1):147-56
references.pmid: 19846378
references.citation: Sensors (Basel). 2010;10(8):7772-88
references.pmid: 22163626