Titlebook: Implantable Cardioverter Defibrillator Therapy: The Engineering-Clinical Interface; Mark W. Kroll (Vice President),Michael H. Lehmann Boo

lethal

The Defibrillation Threshold,icular fibrillation in a variety of clinical circumstances. To ensure that a device is reliable, adequate testing procedures are required at the time of the implant to determine effective defibrillation energies. This information is needed to determine whether the ICD can be programmed with adequate

Moderate

Pathways for Defibrillation Current, for current. The actual flow of current along a pathway is influenced by the electrode materials, surface dimensions and treatments, the conductivities and aniso-tropies of the tissues between electrodes, and the influence of shock strength on conductivity.

mortuary

The Defibrillation Waveform,rillation electrodes and the sequence in which shocks are delivered. The waveform shape also has a direct bearing on the lifetime of the battery used in an ICD since battery and capacitor size are the main determinants in the development of small, efficient devices.. Much work is being done to dimin

Bother

Leads for the ICD,rrhythmias, and their interactions. Factors that influence the success of a defibrillation shock include the underlying physiologic substrate of the heart, the associated characteristics of the tachyarrhythmia, the magnitude and profile of the defibrillation waveform, and the lead/electrode system u

Neolithic

MILL

The High Voltage Capacitor,s capacitor also represents an increasing fraction of the total physical volume of the ICD. In fact, the capacitor (as it will be referred to below, for simplicity) is the primary reason that an ICD is so much larger than an implantable pacemaker.

ASSET

The Pulse Generator, emphasis on packaging of current ICDs has focused on the continual increase of device functions, whether it be therapies (pacing, different defibrillation modes) or features (telemetry, electrocardiogram storage, etc.), with continuing emphasis on decreasing the package size. Until recently, most d

Bouquet

High Power Circuitry, the much higher voltage (usually up to 750 V) necessary for successful defibrillation. Secondly, after this high voltage energy is concentrated in the capacitor, output switching circuitry then transfers this energy to the heart.

完成

The Amplifier: Sensing the Depolarization,onsecutive time intervals demarcated by these events. This is accomplished in a similar fashion to the familiar external heart monitor that relies on electrocardiogram waveforms. Depolarization of heart muscle is the source of the electrical signals for both the ICD and the external heart monitor, b

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