Category Archives: Publications

A transient, closed-loop network of wireless, body-integrated devices for autonomous electrotherapy

Transient closed-loop system for temporary cardiac pacing

WHAT IS KNOWN?

  1. Cardiovascular implantable electronic devices (CIEDs) introduce risk of infections as well as limitations on patient quality of life.
  2. There is a need for minimally invasive devices that provide autonomous electrotherapy over a time frame that matches post-operative needs.

WHAT THIS STUDY ADDS

  1. We propose a transient, closed-loop system for temporary cardiac pacing that incorporates a wireless network of components including:
    • Temporary, bioresorbable, stretchable epicardial pacemaker,
    • Bioresorbable steroid-eluting interface that minimizes local inflammation and fibrosis
    • Subcutaneous, bioresorbable power harvesting unit
    • Set of soft, skin-interfaced sensors that capture ECG, HR etc., to track patient physiology.
    • Wireless RF module that transfers power to the harvesting unit
    • Soft skin-interfaced haptic actuator that communicates via mechanical vibrations
    • Handheld device with software module for real time data visualization and automated adaptive control
  2. The bioresorbable module for cardiac pacing undergoes complete dissolution by natural biological processes after a defined operating time frame. Moreover, the wireless battery recharge through the skin eliminates the need for transcutaneous wires.

LINK TO THE ARTICLE

Choi YS, Jeong H, Yin RT, Avila R, Pfenniger A, Yoo J, Lee JY, Tzavelis A, Lee YJ, Chen SW, Knight HS, Kim S, Ahn HY, Wickerson G, Vázquez-Guardado A, Higbee-Dempsey E, Russo BA, Napolitano MA, Holleran TJ, Razzak LA, Miniovich AN, Lee G, Geist B, Kim B, Han S, Brennan JA, Aras K, Kwak SS, Kim J, Waters EA, Yang X, Burrell A, San Chun K, Liu C, Wu C, Rwei AY, Spann AN, Banks A, Johnson D, Zhang ZJ, Haney CR, Jin SH, Sahakian AV, Huang Y, Trachiotis GD, Knight BP, Arora RK, Efimov IR, Rogers JA. A transient, closed-loop network of wireless, body-integrated devices for autonomous electrotherapy. Science. 2022 May 27;376(6596):1006-1012. doi: 10.1126/science.abm1703. Epub 2022 May 26. PMID: 35617386.

Hardware-Mappable Cellular Neural Networks for Distributed Wavefront Detection in Next-Generation Cardiac Implants

WHAT IS KNOWN?

  1. Organ conformal bioelectronics platform have enabled high-definition ventricular arrhythmia sensing, coupled with electrotherapy.
  2. However, current conformal electronics platforms do not have the ability to perform real time computing to detect arrhythmia rotors and and subsequently deliver appropriate therapy.

WHAT THIS STUDY ADDS?

  1. We propose the use of distributed computing algorithm based on cellular neural networks to provide high classification sensitivity, specificity, accuracy, and precision in detecting arrhythmia rotors and wavefronts.
  2. The compact and efficient computing solution is readily mappable to a memristor based hardware circuitry and could enable a closed-loop solution for smart arrhythmia detection and real-time therapy.

LINK TO THE ARTICLE

Yang Z, Zhang L, Aras K, Efimov IR, Adam GC. Hardware-Mappable Cellular Neural Networks for Distributed Wavefront Detection in Next-Generation Cardiac Implants. Adv. Intell. Syst., 2022.

The Secretome of Atrial Epicardial Adipose Tissue Facilitates Reentrant Arrhythmias by Myocardial Remodeling

Atrial EAT promotes arrhythmias
Atrial EAT promotes arrhythmias

WHAT IS KNOWN?

  1. Obesity is an independent risk factor for sudden cardiac death and atrial fibrillation.
  2. The molecular mechanisms underlying how atrial epicardial adipose tissue (EAT) can induce arrhythmias is not well understood.

WHAT THIS STUDY ADDS

  1. Atrial EAT induces electrophysiological remodeling of myocardium by decreasing electrical coupling, reducing IK1 and depolarizing the maximum diastolic potential.
  2. This results in slowed conduction and increased conduction heterogeneity, depolarized resting potential, which in turn, can facilitate reentrant arrhythmias.

LINK TO THE ARTICLE

Ernault AC, Verkerk AO, Bayer JD, Aras K, Agudo PM, Mohan RA, Veldkamp M, Kawasaki M, van Amersfoorth SCM, Driessen AHG, Efimov IR, de Groot J, Coronel R. The Secretome of Epicardial Adipose Tissue Facilitates Reentrant Arrhythmias by Myocardial RemodelingHeart Rhythm, 2022.

Electrophysiology and Arrhythmogenesis in the Human RVOT

Human RVOT susceptibility to arrhythmias

WHAT IS KNOWN?

  1. Right ventricular outflow tract (RVOT) is a common source of idiopathic ventricular arrhythmias (IVAs). 
  2. However, the mechanisms underlying the RVOT’s unique arrhythmia susceptibility remains not well elucidated due to lack of detailed electrophysiological and molecular studies of human RVOT.

WHAT THE STUDY ADDS

  1. Human RVOT electrophysiology is characterized by shorter APD relative to the right ventricular apical region and drives the transmural dispersion of repolarization and transmural APD dispersion under normal physiological conditions.
  2. Cholinergic stimulation attenuates the arrhythmogenic effects of adrenergic stimulation, including increase in frequency of PVCs and shortening of wavelength.
  3. Arrhythmia in the RV is associated with weak positive spatiotemporal autocorrelation between the epicardial-endocardial arrhythmic wavefronts and reentrant rotors that are relatively more organized in the endocardium.

LINK TO THE ARTICLE

Aras KK, Gams A, Faye NR, Brennan JB, Goldrick K, Li J, Zhong Y, Chiang C, Smith EH, Poston MD, Chivers J, Hanna P, Mori S, Ajijola O, Shivkumar K, Hoover DB, Viventi J, Rogers JA, Bernus O, Efimov IR. Electrophysiology and Arrhythmogenesis of the human right ventricle outflow tract. Circ Arrhythm Electrophysiol. 2022. (Editor’s pick)

Photocurable bioresorbable adhesives as functional intefaces between flexible bioelectronic devices and soft biological tissues

Soft interface materials for joining bioelectronic devices with biological tissues

WHAT IS KNOWN?

  1. Flexible electronic/optoelectronic systems that can physically interface with soft biological tissue surfaces offer revolutionary diagnostic and therapeutic capabilities for various diseases.
  2. However, current approaches to coupling the tissue-device interfaces either through surgical sutures, staples, cuffs, etc., damage the tissue and the devices and often result in adverse immune responses and mechanical instabilities.

WHAT DOES THIS STUDY ADD?

  1. We introduce a functional adhesive bioelectronic-tissue interface material (BTIM), which is mechanically compliant, electrically conductive, and optically transparent. The material can bond to the surface of tissue and the device and provide stable adhesion for several days to months.
  2. We demonstrate the capabilities of this material in live animal models that includes device applications ranging from battery-free optoelectronic systems for deep-brain optogenetics to wireless millimeter-scale pacemakers and flexible multi electrode epicardial arrays.

LINK TO THE ARTICLE

Yang Q, Wei T, Yin RT, Wu M, Xu Y, Koo J, Choi YS, Xie Z, Chen SW, Kandela I, Yao S, Deng Y, Avila R, Liu TL, Bai W, Yang Y, Han M, Zhang Q, Haney CR, Benjamin Lee K, Aras K, Wang T, Seo MH, Luan H, Lee SM, Brikha A, Ghoreishi-Haack N, Tran L, Stepien I, Aird F, Waters EA, Yu X, Banks A, Trachiotis GD, Torkelson JM, Huang Y, Kozorovitskiy Y, Efimov IR, Rogers JA. Photocurable bioresorbable adhesives as functional interfaces between flexible bioelectronic devices and soft biological tissues. Nat Mater. 2021 Jul 29;. doi: 10.1038/s41563-021-01051-x. [Epub ahead of print] PubMed PMID: 34326506.