ECG synthesis from separate wearable bipolar electrodes.

Compared to cabled ECG devices, the use of wearable patches to reconstruct ECG offers a more comfortable alternative for continuous monitoring, especially for patients at home. In this work, we investigate the feasibility of synthesizing a 3-lead ECG signal from 3 separate wearable and wireless patches. We also investigate the effect of their orientation on the synthesized signal. We conduct an experiment on healthy subjects and show the ability of this method to provide a similar ECG signal to the reference, in terms of matching the overall signal pattern. However, a more detailed study would be needed in order to investigate the ability of this method to identify critical conditions for vulnerable subjects.

Rapid assessment of the stability of DNA duplexes by impedimetric real-time monitoring of chemically induced denaturation.

In this article, we report on the electronic monitoring of DNA denaturation by NaOH using electrochemical impedance spectroscopy in combination with fluorescence imaging as a reference technique. The probe DNA consisting of a 36-mer fragment was covalently immobilized on nanocrystalline-diamond electrodes and hybridized with different types of 29-mer target DNA (complementary, single-nucleotide defects at two different positions, and a non-complementary random sequence). The mathematical separation of the impedimetric signals into the time constant for NaOH exposure and the intrinsic denaturation-time constants gives clear evidence that the denaturation times reflect the intrinsic stability of the DNA duplexes. The intrinsic time constants correlate with calculated DNA-melting temperatures. The impedimetric method requires minimal instrumentation, is label-free and fast with a typical time scale of minutes and is highly reproducible. The sensor electrodes can be used repetitively. These elements suggest that the monitoring of chemically induced denaturation at room temperature is an interesting approach to measure DNA duplex stability as an alternative to thermal denaturation at elevated temperatures, used in DNA-melting experiments and single nucleotide polymorphism (SNP) analysis.