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This paper is discussing the development of a wireless Indoor Smart Gardening System with the focus on energy autonomous working. The Smart Gardening System, which is presented in this paper consists of a network of energy autonomous wireless sensor nodes which are used for monitoring important plant parameters like air temperature, soil moisture, pressure or humidity and in future to control an actuator for the plant irrigation and to measure further parameter as light and fertilizer level. Solar energy harvesting is used for powering the wireless nodes without the usage of a battery. Comparable Smart Gardening Systems are usually battery-powered. Furthermore, the overall Smart Gardening System consists of a battery powered gateway based on a Raspberry Pi 3 system, which controls the wireless nodes and collects their sensor data. The gateway is able to send the information to an internet server application and via Wi-Fi to mobile devices. Particularly the architecture of the energy autonomous wireless nodes will be considered because fully energy autonomous wireless networks could not be implemented without special concepts for the energy supply and architecture of the wireless nodes.
Online comment on: "Printing ferromagnetic domains for untethered fast-transforming soft materials"
(2018)
The electrical field (E-field) of the biventricular (BV) stimulation is important for the success of cardiac
resynchronization therapy (CRT) in patients with cardiac insufficiency and widened QRS complex.
The aim of the study was to model different pacing and ablation electrodes and to integrate them into a heart
model for the static and dynamic simulation of BV stimulation and HF ablation in atrial fibrillation (AF).
The modeling and simulation was carried out using the electromagnetic simulation software CST. Five
multipolar left ventricular (LV) electrodes, four bipolar right atrial (RA) electrodes, two right ventricular (RV)
electrodes and one HF ablation catheter were modelled. A selection were integrated into the heart rhythm model
(Schalk, Offenburg) for the electrical field simulation. The simulation of an AV node ablation at CRT was
performed with RA, RV and LV electrodes and integrated ablation catheter with an 8 mm gold tip.
The BV stimulation were performed simultaneously at amplitude of 3 V at the LV electrode and 1 V at the RV
electrode with a pulse width of 0.5 ms each. The far-field potential at the RA electrode tip was 32.86 mV and
185.97 mV at a distance of 1 mm from the RA electrode tip. AV node ablation was simulated with an applied
power of 5 W at 420 kHz at the distal ablation electrode. The temperature at the catheter tip was 103.87 °C after
5 s ablation time and 37.61 °C at a distance of 2 mm inside the myocardium. After 15 s, the temperature was
118.42 °C and 42.13 °C.
Virtual heart and electrode models as well as the simulations of electrical fields and temperature profiles allow
the static and dynamic simulation of atrial synchronous BV stimulation and HF ablation at AF and could be used
to optimize the CRT and AF ablation.
Spectral analysis of signal averaging electrocardiography in atrial and ventricular tachyarrhythmias
(2017)
Background: Targeting complex fractionated atrial electrograms detected by automated algorithms during
ablation of persistent atrial fibrillation has produced conflicting outcomes in previous electrophysiological
studies. The aim of the investigation was to evaluate atrial and ventricular high frequency fractionated electrical
signals with signal averaging technique.
Methods: Signal averaging electrocardiography (ECG) allows high resolution ECG technique to eliminate
interference noise signals in the recorded ECG. The algorithm uses automatic ECG trigger function for signal
averaged transthoracic, transesophageal and intracardiac ECG signals with novel LabVIEW software (National
Instruments, Austin, Texas, USA). For spectral analysis we used fast fourier transformation in combination with
spectro-temporal mapping and wavelet transformation for evaluation of detailed information about the frequency
and intensity of high frequency atrial and ventricular signals.
Results: Spectral-temporal mapping and wavelet transformation of the signal averaged ECG allowed the
evaluation of high frequency fractionated atrial signals in patients with atrial fibrillation and high frequency
ventricular signals in patients with ventricular tachycardia. The analysis in the time domain evaluated
fractionated atrial signals at the end of the signal averaged P-wave and fractionated ventricular signals at the end
of the QRS complex. The analysis in the frequency domain evaluated high frequency fractionated atrial signals
during the P-wave and high frequency fractionated ventricular signals during QRS complex. The combination of
analysis in the time and frequency domain allowed the evaluation of fractionated signals during atrial and
ventricular conduction.
Conclusions: Spectral analysis of signal averaging electrocardiography with novel LabVIEW software can
utilized to evaluate atrial and ventricular conduction delays in patients with atrial fibrillation and ventricular
tachycardia. Complex fractionated atrial electrograms may be useful parameters to evaluate electrical cardiac
arrhythmogenic signals in atrial fibrillation ablation.
Heart rhythm model and simulation of electrophysiological studies and high-frequency ablations
(2017)
Background: Target of the study was to create an accurate anatomic CAD heart rhythm model, and to show its
usefulness for cardiac electrophysiological studies and high-frequency ablations. The method is more careful for
the patients’ health and has the potential to replace clinical studies due to its high efficiency regarding time and
costs
Methods: All natural heart components of the new HRM were based on MRI records, which guaranteed
electronic functionality. The software CST was used for the construction, while CST’s material library assured
genuine tissue properties. It should be applicable to simulate different heart rhythm diseases as well as various
diffusions of electromagnetic fields, caused by electrophysiological conduction, inside the heart tissue.
Results: It was achievable to simulate sinus rhythm and fourteen different heart rhythm disturbance with
different atrial and ventricular conduction delays. The simulated biological excitation of healthy and sick HRM
were plotted by simulated electrodes of four polar right atrial catheter, six polar His bundle catheter, ten polar
coronary sinus catheter, four polar ablation catheter and eight polar transesophageal left cardiac catheter.
Accordingly, six variables were rebuilt and inserted into the anatomic HRM in order to establish heart catheters
for ECG monitoring and HF ablation. The HF ablation catheters made it possible to simulate various types of
heart rhythm disturbance ablations with different HF ablation catheters and also showed a functional
visualisation of tissue heating. The use of tetrahedral meshing HRM made it attainable to store the results faster
accompanied by a higher degree of space saving. The smart meshing function reduced unnecessary high
resolutions for coarse structures.
Conclusions: The new HRM for EPS simulation may be additional useful for simulation of heart rhythm
disturbance, cardiac pacing, HF ablation and for locating and identification of complex fractioned signals within
the atrium during atrial fibrillation HF ablation.