Simultaneous ventricular sympathetic reinnervation assessed by MIBG and sinus node sympathetic reinnervation assessed by heart rate variability in supine as in upright position were detected only in two patients (17%). The results of our study show that eventual sinus node sympathetic reinnervation and left ventricular sympathetic reinnervation do not occur simultaneously.

The recent trend in electrocardiogram (ECG) device development is towards wireless body sensors applied for patient monitoring. The ultimate goal is to develop a multi-functional body sensor that will provide synchronized vital bio-signs of the monitored user. In this paper, we present an ECG sensor for long-term monitoring, which measures the surface potential difference between proximal electrodes near the heart, called differential ECG lead or differential lead, in short. The sensor has been certified as a class IIa medical device and is available on the market under the trademark Savvy ECG. An improvement from the user's perspective-immediate access to the measured data-is also implemented into the design. With appropriate placement of the device on the chest, a very clear distinction of all electrocardiographic waves can be achieved, allowing for ECG recording of high quality, sufficient for medical analysis. Experimental results that elucidate the measurements from a differential lead regarding sensors' position, the impact of artifacts, and potential diagnostic value, are shown. We demonstrate the sensors' potential by presenting results from its various areas of application: medicine, sports, veterinary, and some new fields of investigation, like hearth rate variability biofeedback assessment and biometric authentication.Sensors 2020, 20, 1695 2 of 17 have evolved into smaller and more powerful devices for recording high-quality single or multi-lead ECG, they cause discomfort for the patients because the device needs to be carried on the body with all the cabling. Furthermore, they still have limited duration of the recordings up to a maximum of 14 days. On the other hand, the (wireless) ILRs are lightweight devices (usually only around 17 g weight) implanted under the skin [5] and provide comfortable long-term ECG monitoring for up to several years. However, the ILRs are invasive devices and their capacity for ECG recording is limited to several recordings, each with a duration of a couple of minutes. Consequently, if the patient equipped with the device does not visit a medical office to retrieve the measurements in a timely manner, older recordings are overwritten.The provision of mobile health (mHealth) services, like patient monitoring in hospitals [6], remote medical support, or monitoring during sport activities, requires for these ECG devices to allow greater patient mobility than the Holter monitor [7-9] and additionally provide wireless transmission of the data from the device to a nearby personal terminal (smartphone, tablet) connected to the Internet [10]. Motivated by these challenges, we have envisioned to design a monitoring system for synchronous measurement of vital bio-signs [11,12]. Our ultimate goal was to combine minimal number of body sensors with different functions into in a single one, i.e., to develop a multi-functional body sensor. Namely, our long-term experience with MECG devices has shown us that a significant amount of information about vital functions, including ECG, can be...

We propose a new body sensor for extracting the respiration rate based on the amplitude changes in the body surface potential differences between two proximal body electrodes. The sensor could be designed as a plaster-like reusable unit that can be easily fixed onto the surface of the body. It could be equipped either with a sufficiently large memory for storing the measured data or with a low-power radio system that can transmit the measured data to a gateway for further processing. We explore the influence of the sensor's position on the quality of the extracted results using multi-channel ECG measurements and considering all the pairs of two neighboring electrodes as potential respiration-rate sensors. The analysis of the clinical measurements, which also include reference thermistor-based respiration signals, shows that the proposed approach is a viable option for monitoring the respiration frequency and for a rough classification of breathing types. The obtained results were evaluated on a wireless prototype of a respiration body sensor. We indicate the best positions for the respiration body sensor and prove that a single sensor for body surface potential difference on proximal skin electrodes can be used for combined measurements of respiratory and cardiac activities.

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The decreases in alpha1, average FD, and high FD indicate that a profound decay of cardiac complexity and fractal correlation can be observed after off-pump CABG. Furthermore, a more extensive impairment of nonlinear indices was observed in patients who developed postoperative arrhythmias than in those who remained in stable sinus rhythm. Our findings suggest that the postoperative hyperadrenergic setting acts as a preliminary condition in which both reduced and enhanced vagal activity may predispose patients to arrhythmia, indicating that postoperative rhythm disturbances are an end point associated with divergent autonomic substrates.