title: Epidermal mechano-acoustic sensing electronics for cardiovascular diagnostics and human-machine interfaces.
abstract: Physiological mechano-acoustic signals, often with frequencies and intensities that are beyond those associated with the audible range, provide information of great clinical utility. Stethoscopes and digital accelerometers in conventional packages can capture some relevant data, but neither is suitable for use in a continuous, wearable mode, and both have shortcomings associated with mechanical transduction of signals through the skin. We report a soft, conformal class of device configured specifically for mechano-acoustic recording from the skin, capable of being used on nearly any part of the body, in forms that maximize detectable signals and allow for multimodal operation, such as electrophysiological recording. Experimental and computational studies highlight the key roles of low effective modulus and low areal mass density for effective operation in this type of measurement mode on the skin. Demonstrations involving seismocardiography and heart murmur detection in a series of cardiac patients illustrate utility in advanced clinical diagnostics. Monitoring of pump thrombosis in ventricular assist devices provides an example in characterization of mechanical implants. Speech recognition and human-machine interfaces represent additional demonstrated applications. These and other possibilities suggest broad-ranging uses for soft, skin-integrated digital technologies that can capture human body acoustics.
authors.affiliation: Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Yuhao
authors.identifier: 0000-0002-2442-5690
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: James J S
authors.initials: JJ
authors.lastname: Norton
authors.affiliation: Department of Electrical, Computer and Energy Engineering, University of Colorado Boulder, Boulder, CO 80309, USA.
authors.forename: Raza
authors.identifier: 0000-0002-9491-5783
authors.initials: R
authors.lastname: Qazi
authors.affiliation: Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO 80309, USA.
authors.forename: Zhanan
authors.initials: Z
authors.lastname: Zou
authors.affiliation: Department of Medicine, Sarver Heart Center, and Department of Biomedical Engineering Graduate Interdisciplinary Program, The University of Arizona, Tucson, AZ 85724, USA.
authors.forename: Kaitlyn R
authors.identifier: 0000-0002-8245-3796
authors.initials: KR
authors.lastname: Ammann
authors.affiliation: Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Hank
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Lingqing
authors.initials: L
authors.lastname: Yan
authors.affiliation: Department of Medicine, Sarver Heart Center, and Department of Biomedical Engineering Graduate Interdisciplinary Program, The University of Arizona, Tucson, AZ 85724, USA.
authors.forename: Phat L
authors.initials: PL
authors.lastname: Tran
authors.affiliation: Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Kyung-In
authors.initials: KI
authors.lastname: Jang
authors.affiliation: Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Jung Woo
authors.initials: JW
authors.lastname: Lee
authors.affiliation: Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Douglas
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Kristopher A
authors.identifier: 0000-0002-8963-9796
authors.initials: KA
authors.lastname: Kilian
authors.affiliation: Department of Internal Medicine, Eulji University College of Medicine, Daejeon, Korea.
authors.forename: Sung Hee
authors.initials: SH
authors.lastname: Jung
authors.affiliation: Department of Aerospace Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Timothy
authors.identifier: 0000-0001-7883-7300
authors.initials: T
authors.lastname: Bretl
authors.affiliation: Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO 80309, USA.; Materials Science and Engineering Program, University of Colorado Boulder, Boulder, CO 80309, USA.
authors.forename: Jianliang
authors.initials: J
authors.lastname: Xiao
authors.affiliation: Department of Medicine, Sarver Heart Center, and Department of Biomedical Engineering Graduate Interdisciplinary Program, The University of Arizona, Tucson, AZ 85724, USA.
authors.forename: Marvin J
authors.identifier: 0000-0002-7864-6691
authors.initials: MJ
authors.lastname: Slepian
authors.affiliation: Department of Civil and Environmental Engineering and Department of Mechanical Engineering, Northwestern University, Evanston, IL 60208, USA.
authors.forename: Yonggang
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Department of Electrical, Computer and Energy Engineering, University of Colorado Boulder, Boulder, CO 80309, USA.; Materials Science and Engineering Program, University of Colorado Boulder, Boulder, CO 80309, USA.
authors.forename: Jae-Woong
authors.initials: JW
authors.lastname: Jeong
authors.affiliation: Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Rogers
mesh_terms: D000818:Animals; D003935:Diagnostic Techniques, Cardiovascular / Q000295:instrumentation*; D004582:Electronics, Medical; D004817:Epidermis; D006337:Heart Murmurs / Q000175:diagnosis / Q000503:physiopathology; D006353:Heart-Assist Devices / Q000009:adverse effects*; D006801:Humans; D051379:Mice; D013927:Thrombosis / Q000175:diagnosis / Q000503:physiopathology; D014584:User-Computer Interface
keywords: Epidermal; accelerometer; acoustic; cardiovascular; flexible; human-machine interface; seismocardiology; stretchable; ventricle assist device