Impedance compensated passive implantable atrial defibrillator

PR Walsh, PA Rodrigues, JJ Velasquez, N Waterman, OJ Escalona

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

An impedance compensated passive implantable atrial defibrillator is reported. The two-part system consists of a handheld lithium-ion powered base unit (external power transmitter) and a passive (battery free) implantable coil (power receiver), with integrated rectifilter and power control unit, electrocardiogram (ECG) and bioimpedance measurement circuits, data communications circuitry and atrial connection leads. The system is designed to operate in two distinct modes: cardiac sense mode (wake-up, measure the impedance of the cardiac substrate and communicate data to the external base unit) and shock mode (delivery of an ECG synchronised impedance compensated monophasic very low tilt rectilinear shock waveform). A prototype was implemented and tested. In the sense mode, up to 5 W of sustained DC power was delivered across a 2.5 cm air–skin barrier with approximately 40% DC-to-DC power transfer efficiency at a transmission frequency of 185 kHz achieved, thereby providing 15.9 VDC (320 mA) to the implant side for measurement and communication at 433 MHz with the base unit. In the shock delivery mode, >186.9 W (rectilinear monophasic shock pulse: 100 V, 1.9 A, 12 ms duration) was repeatedly and reliably delivered transcutaneously to a 50 Ω cardiac load. Further testing in ten porcine models verified the in vivo operation, with inter-catheter impedance variations of ±20.1% measured between successive defibrillation attempts.
LanguageEnglish
Pages1192-1193
JournalElectronics Letters
Volume50
Issue number17
DOIs
Publication statusPublished - 14 Aug 2014

Fingerprint

Defibrillators
Electrocardiography
Integrated control
Catheters
Communication
Power control
Transmitters
Skin
Lithium
Networks (circuits)
Ions
Testing
Substrates
Air

Keywords

  • bioelectric potentials
  • diseases
  • defibrillators
  • synchronisation
  • low-power electronics
  • catheters
  • medical signal processing
  • coils
  • passive filters
  • skin
  • electrocardiography
  • sustained dc power
  • intercatheter impedance variations
  • cardiac substrate
  • dc-to-dc power transfer efficiency
  • bioimpedance measurement circuits
  • ECG synchronised impedance
  • shock delivery mode
  • passive battery free-implantable coil power receiver
  • cardiac sense mode
  • power control unit
  • frequency 433 MHz
  • two-part system
  • external power transmitter
  • hand-held lithium-ion powered base unit
  • atrial connection leads
  • electrocardiogram
  • air-skin barrier
  • shock mode
  • very low tilt rectilinear shock waveform
  • integrated rectifilter
  • rectilinear monophasic shock pulse
  • data communications circuitry
  • impedance compensated passive implantable atrial defibrillator.

Cite this

Walsh, PR ; Rodrigues, PA ; Velasquez, JJ ; Waterman, N ; Escalona, OJ. / Impedance compensated passive implantable atrial defibrillator. In: Electronics Letters. 2014 ; Vol. 50, No. 17. pp. 1192-1193.
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author = "PR Walsh and PA Rodrigues and JJ Velasquez and N Waterman and OJ Escalona",
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Walsh, PR, Rodrigues, PA, Velasquez, JJ, Waterman, N & Escalona, OJ 2014, 'Impedance compensated passive implantable atrial defibrillator', Electronics Letters, vol. 50, no. 17, pp. 1192-1193. https://doi.org/10.1049/el.2014.1872

Impedance compensated passive implantable atrial defibrillator. / Walsh, PR; Rodrigues, PA; Velasquez, JJ; Waterman, N; Escalona, OJ.

In: Electronics Letters, Vol. 50, No. 17, 14.08.2014, p. 1192-1193.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Impedance compensated passive implantable atrial defibrillator

AU - Walsh, PR

AU - Rodrigues, PA

AU - Velasquez, JJ

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AU - Escalona, OJ

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N2 - An impedance compensated passive implantable atrial defibrillator is reported. The two-part system consists of a handheld lithium-ion powered base unit (external power transmitter) and a passive (battery free) implantable coil (power receiver), with integrated rectifilter and power control unit, electrocardiogram (ECG) and bioimpedance measurement circuits, data communications circuitry and atrial connection leads. The system is designed to operate in two distinct modes: cardiac sense mode (wake-up, measure the impedance of the cardiac substrate and communicate data to the external base unit) and shock mode (delivery of an ECG synchronised impedance compensated monophasic very low tilt rectilinear shock waveform). A prototype was implemented and tested. In the sense mode, up to 5 W of sustained DC power was delivered across a 2.5 cm air–skin barrier with approximately 40% DC-to-DC power transfer efficiency at a transmission frequency of 185 kHz achieved, thereby providing 15.9 VDC (320 mA) to the implant side for measurement and communication at 433 MHz with the base unit. In the shock delivery mode, >186.9 W (rectilinear monophasic shock pulse: 100 V, 1.9 A, 12 ms duration) was repeatedly and reliably delivered transcutaneously to a 50 Ω cardiac load. Further testing in ten porcine models verified the in vivo operation, with inter-catheter impedance variations of ±20.1% measured between successive defibrillation attempts.

AB - An impedance compensated passive implantable atrial defibrillator is reported. The two-part system consists of a handheld lithium-ion powered base unit (external power transmitter) and a passive (battery free) implantable coil (power receiver), with integrated rectifilter and power control unit, electrocardiogram (ECG) and bioimpedance measurement circuits, data communications circuitry and atrial connection leads. The system is designed to operate in two distinct modes: cardiac sense mode (wake-up, measure the impedance of the cardiac substrate and communicate data to the external base unit) and shock mode (delivery of an ECG synchronised impedance compensated monophasic very low tilt rectilinear shock waveform). A prototype was implemented and tested. In the sense mode, up to 5 W of sustained DC power was delivered across a 2.5 cm air–skin barrier with approximately 40% DC-to-DC power transfer efficiency at a transmission frequency of 185 kHz achieved, thereby providing 15.9 VDC (320 mA) to the implant side for measurement and communication at 433 MHz with the base unit. In the shock delivery mode, >186.9 W (rectilinear monophasic shock pulse: 100 V, 1.9 A, 12 ms duration) was repeatedly and reliably delivered transcutaneously to a 50 Ω cardiac load. Further testing in ten porcine models verified the in vivo operation, with inter-catheter impedance variations of ±20.1% measured between successive defibrillation attempts.

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KW - synchronisation

KW - low-power electronics

KW - catheters

KW - medical signal processing

KW - coils

KW - passive filters

KW - skin

KW - electrocardiography

KW - sustained dc power

KW - intercatheter impedance variations

KW - cardiac substrate

KW - dc-to-dc power transfer efficiency

KW - bioimpedance measurement circuits

KW - ECG synchronised impedance

KW - shock delivery mode

KW - passive battery free-implantable coil power receiver

KW - cardiac sense mode

KW - power control unit

KW - frequency 433 MHz

KW - two-part system

KW - external power transmitter

KW - hand-held lithium-ion powered base unit

KW - atrial connection leads

KW - electrocardiogram

KW - air-skin barrier

KW - shock mode

KW - very low tilt rectilinear shock waveform

KW - integrated rectifilter

KW - rectilinear monophasic shock pulse

KW - data communications circuitry

KW - impedance compensated passive implantable atrial defibrillator.

UR - http://digital-library.theiet.org

U2 - 10.1049/el.2014.1872

DO - 10.1049/el.2014.1872

M3 - Article

VL - 50

SP - 1192

EP - 1193

JO - Electronics Letters

T2 - Electronics Letters

JF - Electronics Letters

SN - 0013-5194

IS - 17

ER -