Functional characterization of developing heart in embryos using Electric Potential Sensors

The characterization of the electrocardiographic activity of the living zebrafish heart during early developmental stages is a challenging task. Most of the available techniques are limited to heartbeat rate quantification being this inaccurate. Other invasive methodologies require the insertion of electrodes noise isolated environments and advanced amplification stages making these techniques very expensive. In this paper, we present a novel and non-invasive sensor development to characterize the functional activity of the developing heart of in vivo zebrafish embryos. The design is based on the Electric Potential Sensing technology patented at Sussex which has been developed to achieve reproducibility and continuous detection. We present preliminary functional characterization data of the developing zebrafish heart starting at 3 days-post-fertilization. Results show that using the proposed system for mapping the electrocardiographic activity of the zebrafish heart at early developmental stages is successfully accomplished. This is the first time that such a sensitive sensor has been developed for measuring the electrical changes occurring on micron sized (< 100 µm) living samples such as the zebrafish heart

An experimental method for bio-signal denoising using unconventional sensors

In bio-signal denoising, current methods reported in literature consider purely simulated envi-ronments, requiring high computational powers and signal processing algorithms that may in-troduce signal distortion. To achieve an efficient noise reduction, such methods require previous knowledge of the noise signals or to have certain periodicity and stability, making the noise es-timation difficult to predict. In this paper, we solve these challenges through the development of an experimental method applied for bio-signal denoising using a combined approach. This is based on the implementation of unconventional electric field sensors used for creating a noise replica required to obtain the ideal Wiener filter transfer function and achieve further noise reduction. This work aims to investigate the suitability of the proposed approach for the real-time noise reduction affecting bio-signal recordings. The experimental evaluation presented considers two scenarios: a) human bio-signals trials including electrocardiogram, electromyogram and elec-trooculogram; and b) bio-signal recordings from the MIT-MIH arrhythmia database. The per-formance of the proposed method is evaluated using qualitative (i.e. power spectral density) and quantitative criteria (i.e. signal-to-noise ratio and mean square error) followed by a comparison between the proposed methodology and state of the art denoising methods. The results indicate that the combined approach proposed in this paper can be used for noise reduction in electro-cardiogram, electromyogram and electrooculogram signals achieving noise attenuation levels of 26.4 dB, 21.2 dB and 40.8 dB, respectively

Characterisation of textile embedded electrodes for use in a neonatal smart mattress electrocardiography system

Heart rate monitoring is the predominant quantitative health indicator of a newborn in the delivery room. A rapid and accurate heart rate measurement is vital during the first minutes after birth. Clinical recommendations suggest that electrocardiogram (ECG) monitoring should be widely adopted in the neonatal intensive care unit to reduce infant mortality and improve long term health outcomes in births that require intervention. Novel non-contact electrocardiogram sensors can reduce the time from birth to heart rate reading as well as providing unobtrusive and continuous monitoring during intervention. In this work we report the design and development of a solution to provide high resolution, real time electrocardiogram data to the clinicians within the delivery room using non-contact electric potential sensors embedded in a neonatal intensive care unit mattress. A real-time high-resolution electrocardiogram acquisition solution based on a low power embedded system was developed and textile embedded electrodes were fabricated and characterised. Proof of concept tests were carried out on simulated and human cardiac signals, producing electrocardiograms suitable for the calculation of heart rate having an accuracy within ±1 beat per minute using a test ECG signal, ECG recordings from a human volunteer with a correlation coefficient of ~ 87% proved accurate beat to beat morphology reproduction of the waveform without morphological alterations and a time from application to heart rate display below 6 s. This provides evidence that flexible non-contact textile-based electrodes can be embedded in wearable devices for assisting births through heart rate monitoring and serves as a proof of concept for a complete neonate electrocardiogram monitoring system

Evaluation of screen-printing techniques for embedding ECG sensors in medical devices

Heart rate monitoring is the most important indicator to evaluate the clinical status of a newborn during birth. Approximately 90% of newborn infants make the transition from the intrauterine to extra uterine environment without major complications; however, the remaining 10% of newborn infants require assistance during this transition. Heart rate monitoring is required for guiding further interventions in the event of complications such as the need for resuscitation. In this work we evaluate the suitability of embedding electrometer-based-amplifier sensors employing novel screen-printing techniques into medical devices. We compare our results with traditional copper based wired electrodes. Our implementation was able to acquire electrocardiogram with enough signal to noise ratio, suitable for heart rate detection with a 1% loss of heart rate accuracy, compared with the copper-based electrodes. Our device has the potential to be embedded in devices for assisting births though heart rate monitoring

QoSatAr: a cross-layer architecture for E2E QoS provisioning over DVB-S2 broadband satellite systems

This article presents QoSatAr, a cross-layer architecture developed to provide end-to-end quality of service (QoS) guarantees for Internet protocol (IP) traffic over the Digital Video Broadcasting-Second generation (DVB-S2) satellite systems. The architecture design is based on a cross-layer optimization between the physical layer and the network layer to provide QoS provisioning based on the bandwidth availability present in the DVB-S2 satellite channel. Our design is developed at the satellite-independent layers, being in compliance with the ETSI-BSM-QoS standards. The architecture is set up inside the gateway, it includes a Re-Queuing Mechanism (RQM) to enhance the goodput of the EF and AF traffic classes and an adaptive IP scheduler to guarantee the high-priority traffic classes taking into account the channel conditions affected by rain events. One of the most important aspect of the architecture design is that QoSatAr is able to guarantee the QoS requirements for specific traffic flows considering a single parameter: the bandwidth availability which is set at the physical layer (considering adaptive code and modulation adaptation) and sent to the network layer by means of a cross-layer optimization. The architecture has been evaluated using the NS-2 simulator. In this article, we present evaluation metrics, extensive simulations results and conclusions about the performance of the proposed QoSatAr when it is evaluated over a DVB-S2 satellite scenario. The key results show that the implementation of this architecture enables to keep control of the satellite system load while guaranteeing the QoS levels for the high-priority traffic classes even when bandwidth variations due to rain events are experienced. Moreover, using the RQM mechanism the user’s quality of experience is improved while keeping lower delay and jitter values for the high-priority traffic classes. In particular, the AF goodput is enhanced around 33% over the drop tail scheme (on average)

Electric potential sensing for electrocardiology

Electric potential sensing offers benefits over other methods of heart rate acquisition such as traditional silver chloride electrocardiogram and photoplethysmography. This talk outlines the state of the art in neonatal heart rate acquisition and and delves into some of the research work and collaborations that have been performed at the University of Sussex towards a functioning electric potential sensing prototype for use with newborns

An Experimental Method for Bio-Signal Denoising Using Unconventional Sensors

In bio-signal denoising, current methods reported in the literature consider purely simulated environments, requiring high computational powers and signal processing algorithms that may introduce signal distortion. To achieve an efficient noise reduction, such methods require previous knowledge of the noise signals or to have certain periodicity and stability, making the noise estimation difficult to predict. In this paper, we solve these challenges through the development of an experimental method applied to bio-signal denoising using a combined approach. This is based on the implementation of unconventional electric field sensors used for creating a noise replica required to obtain the ideal Wiener filter transfer function and achieve further noise reduction. This work aims to investigate the suitability of the proposed approach for real-time noise reduction affecting bio-signal recordings. The experimental evaluation presented here considers two scenarios: (a) human bio-signals trials including electrocardiogram, electromyogram and electrooculogram; and (b) bio-signal recordings from the MIT-MIH arrhythmia database. The performance of the proposed method is evaluated using qualitative criteria (i.e., power spectral density) and quantitative criteria (i.e., signal-to-noise ratio and mean square error) followed by a comparison between the proposed methodology and state of the art denoising methods. The results indicate that the combined approach proposed in this paper can be used for noise reduction in electrocardiogram, electromyogram and electrooculogram signals, achieving noise attenuation levels of 26.4 dB, 21.2 dB and 40.8 dB, respectively

Biomedical applications of sensing and laser-assisted high precision robotic systems

The development of future surgical therapies has driven the efforts to increase the precision of robot-guided manipulators beyond sub-millimeter accuracies. Medical applications such as reconstructive microsurgeries, surgical anastomosis, vitreoretinal eye surgery, and neurosurgery still require achieving precision comparable to the size of human cells. Most commercially available robotic systems can achieve millimeter accuracies with very few examples of high precision instruments achieving accuracies slightly below the millimetric scale. In this presentation, the modeling, design, and construction of innovative robotic systems delivering micron motion accuracies will be discussed along with proof-of-concept experimental tests demonstrating the potential to develop high precision biomedical tasks. Furthermore, the design and implementation of laser-based tools will be discussed outlining application-specific requirements as well as target biomedical applications.</p

Towards the correlation between human hydration and the electrical activity of the heart using Electric Potential Sensors

Dehydration has been associated with several adverse effects on health and well-being such as the progressive reduction in the ability to concentrate as well as the levels of alertness when fluid intake is restricted. Currently, hydration assessment has been performed using various methods ranging from simple clinical procedures to more complex techniques. However, most of these currently used technologies are not accurate and in some cases are extremely invasive. In this paper we propose a new methodology to assess human hydration using Electric Potential Sensing technology. It is based on measuring the electric field generated by the human body. We propose to correlate the electrical activity of the heart with different levels of human hydration. For evaluating this proof of principle the proposed methodology was assessed considering several healthy subjects. The results presented show that it is possible to assess the level of hydration by measuring changes in the electric field generated by the heart using our proposed sensor technology