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Sweat secreted by the human eccrine sweat glands can provide valuable biomarker information during exercise. Real-time non-invasive biomarker recordings are therefore useful for evaluating the physiological conditions of an athlete such as their hydration status during endurance exercise. This work describes a wearable sweat biomonitoring patch incorporating printed electrochemical sensors into a plastic microfluidic sweat collector and data analysis that shows the real-time recorded sweat biomarkers can be used to predict a physiological biomarker. The system was placed on subjects carrying out an hour-long exercise session and results were compared to a wearable system using potentiometric robust silicon-based sensors and to commercially available HORIBA-LAQUAtwin devices. Both prototypes were applied to the real-time monitoring of sweat during cycling sessions and showed stable readings for around an hour. Analysis of the sweat biomarkers collected from the printed patch prototype shows that their real-time measurements correlate well (correlation coefficient ≥0.65 ) with other physiological biomarkers such as heart rate and regional sweat rate collected in the same session. We show for the first time, that the real-time sweat sodium and potassium concentration biomarker measurements from the printed sensors can be used to predict the core body temperature with root mean square error (RMSE) of 0.02 °C which is 71% lower compared to the use of only the physiological biomarkers. These results show that these wearable patch technologies are promising for real-time portable sweat monitoring analytical platforms, especially for athletes performing endurance exercise.

This paper proposes a compact switched-capacitor (SC) multi-bit flash quantizer for low-power high-resolution delta-sigma modulators (¿SMs). First, a general power model for single-loop ¿SMs is presented to show the importance of using multi-bit quantization when facing high-resolution specifications. In this context, a SC multi-bit quantizer circuit is proposed, which exhibits low-power operation, high modularity, single comparator design and compatibility with both multi-feedforward ¿SM architectures and other SC low-power circuit techniques, like clocked comparators and switched OpAmps. A practical 50-kHz 16-bit ¿SM design case is also presented., Peer Reviewed, Postprint (published version)

The invention relates to read-out integrated circuits (ROIC) for reading image sensor arrays. The invention comprises a novel pulse modulator topology as part of the analog-digital converter for active digital pixels, which attenuates signal losses caused by the initialisation times of the analog integrator. The invention also comprises the use of the function enabling cancellation of the low-frequency noise of the analog integrator using correlated double sampling. The invention is advantageous over current technology in that it increases the image capture speed or alternatively reduces the power consumption in active pixels without a loss of resolution., La invención relaciona a los circuitos integrados del read-out (ROIC) para las agrupaciones del sensor de imagen de la lectura. La invención comprende una topología nueva del modulador del impulso como parte del convertidor análogo-digital para los pixeles digitales activos, que atenúa las pérdidas de la señal causadas por el tiempo de la inicialización del integrador análogo. La invención también comprende el uso de la función posibilitando la cancelación del ruido de baja frecuencia del integrador análogo que usa muestreo doble correlacionado. La invención es tecnología actual excesiva ventajosa en que él los aumentos la velocidad de la captura de la imagen o reduce alternativomente el consumo de energía en pixeles activos sin una pérdida de la resolución.