Wearable chemical sensors: characterization of heart rate electrodes using electrochemical impedance spectroscopy

Wearable monitoring systems have become very popular in the health and sports industry in recent years. Noninvasive measurements, such as speed, direction, acceleration, strain, impact and heart rate, are being utilized across countless different monitoring platforms. Heart rate monitoring is of particular interest, since this one diagnostic can provide descriptive information about the health of the user in all levels of activity. In addition, there is a recent exploration of different acquisition techniques and placement of sensors on the body in order to increase ease of use and comfort of the device. Optimizing these factors is a high priority as they will ultimately determine the extent to which device is used. However, it is important that accuracy does not suffer for the sake of comfort. Herein, a series of measurements comparing heart rate monitoring electrodes is presented. Using electrochemical impedance spectroscopy, textile electrodes are compared to disposable Ag/AgCl electrodes. Equivalent circuit modeling is used to understand the reaction kinetics occurring within both types of electrodes and how they differ from each other. In addition, nonmotion on-body measurements are performed to observe the practical differences between the electrodes. This work will provide a foundation to assess future generations of heart rate monitoring electrodes

Characterization of heart rate electrodes using electrochemical impedance spectroscopy

Wearable monitoring systems have flooded the health and sports industry in recent years. Heart rate monitors have taken many forms, relying on a wide variety of different measurement techniques to measure the heart rate signal.1-3 Despite these recent advancements, commercially available systems still require improvements in many aspects, including battery life, wearability and signal acquisition to become reliable monitoring systems, that meet current inpatient monitoring.4 Standard Ag/AgCl disposable monitoring electrodes rely on a reduction-oxidation reaction to produce clear, reliable electrocardiogram (ECG) signal for inpatient monitoring5, however, these electrodes are not suitable for athletic monitoring in real-time, most notably for the difficulty of use. A series of non-motion electrochemical impedance experiments were conducted in order to determine the charge transfer resistance of various types of heart rate monitoring electrodes with respect to temperature. In these experiments, a textile electrode is compared against two types of solid-gel Ag/AgCl single use monitoring electrodes, which are used as the gold standard for non-motion measurements. The test method created here will serve as a basis to evaluate future heart rate monitoring electrodes in both motion and non-motion applications. 1 http://wellograph.com/. Retrieved 28 April 2014. 2 http://www.lg.com/us/fitness-activity-trackers/lg-FR74-heart-rate-monitor. Retrieved 28 April 2014. 3 http://www.polar.com/en. Retrieved 28 April 2014. 4 Pantelopoulos, A., & Bourbakis, N. G. (2010). A Survey on Wearable Sensor-Based Systems for Health Monitoring and Prognosis. IEEE Transactions on Systems, Man, and Cybernetics, Part C: Applications and Reviews, 40(1), 1–12. 5 Chi, Y. M., Jung, T.-P., & Cauwenberghs, G. (2010). Dry-Contact and Noncontact Biopotential Electrodes: Methodological Review. IEEE Reviews in Biomedical Engineering, 3, 106–119

From Consultation to Consent: Squaring the Circle?

This article analyses the apparent tensions between the current Canadian law on the Crown's duty to consult with Indigenous peoples, which generally refuses an Indigenous veto over proposed land uses in traditional lands, and the principle of prior informed indigenous consent, as enshrined in the recent U.N. Declaration of the Rights of Indigenous Peoples. The tension between these competing visions of the rights of Indigenous communities has given rise not just to theoretical legal conflicts, but also to destructive conflicts on the ground. The author argues that attention to the dialogic framework within which Indigenous concerns are addressed during consultations, and particularly to indigenous peoples' participation in developing that framework, is key to managing those conflicts effectively and to reconciling current Canadian law and practice with the principles of the U.N. Declaration. Next it examines a question on which Canadian consultation law is largely silent: the allocation of benefits derived from developments on Indigenous traditional lands. Finally, the analysis turns to the principle of free, prior and informed consent to the substance of proposed developments on traditional lands. The article concludes that the objective of obtaining such consent is a salutary one that has been wrongly marginalized in both the jurisprudence and Canadian government practice

Traditional Indian Justice in Ontario: A Role for the Present?

It is the author\u27s position that for too long the study of Indian law in Canada has meant the study of law imposed upon Canadian Indians. It is suggested that the study of the indigenous law ways of Ontario\u27s native Indians has been wrongly neglected This is so not merely because of the historical interest of the subject to Indians and non-Indians alike, but also because the study of traditional law ways provides an opportunity for modem native communities to understand the historical continuity of local responsibility for justice among natives and to build upon that tradition in assuming more responsibility for the administration of justice in native communities today. The approach of this paper is threefold. Its starting point is a review of recent studies which indicate that native men and women are dramatically over-represented in the province\u27s prison system, particularly for minor offences. The paper then investigates the historical evidence that social mechanisms existed in traditional lroquois and Cree-Ojibwa societies in Ontario that performed the functions of a justice system in those societies before Euro-Canadian law was imposed on them. Next, the author considers whether, and to what extent, traditional native approaches to conflict resolution in Ontario are in accord with modern Canadian criminal justice policy. Concluding that the values which inspired traditional native justice ways and current criminal policy are indeed compatible, the author proposes that native communities in Ontario be encouraged to rediscover the value of their justice traditions and presents concrete examples of the sorts of current Canadian justice initiatives which seem to offer particular hope for the future

Traditional Indian Justice in Ontario: A Role for the Present?

It is the author\u27s position that for too long the study of Indian law in Canada has meant the study of law imposed upon Canadian Indians. It is suggested that the study of the indigenous law ways of Ontario\u27s native Indians has been wrongly neglected This is so not merely because of the historical interest of the subject to Indians and non-Indians alike, but also because the study of traditional law ways provides an opportunity for modem native communities to understand the historical continuity of local responsibility for justice among natives and to build upon that tradition in assuming more responsibility for the administration of justice in native communities today. The approach of this paper is threefold. Its starting point is a review of recent studies which indicate that native men and women are dramatically over-represented in the province\u27s prison system, particularly for minor offences. The paper then investigates the historical evidence that social mechanisms existed in traditional lroquois and Cree-Ojibwa societies in Ontario that performed the functions of a justice system in those societies before Euro-Canadian law was imposed on them. Next, the author considers whether, and to what extent, traditional native approaches to conflict resolution in Ontario are in accord with modern Canadian criminal justice policy. Concluding that the values which inspired traditional native justice ways and current criminal policy are indeed compatible, the author proposes that native communities in Ontario be encouraged to rediscover the value of their justice traditions and presents concrete examples of the sorts of current Canadian justice initiatives which seem to offer particular hope for the future

Defending the Weak and Fighting Unfairness: Can Mediators Respond to the Challenge?

As mediation gains in popularity as a tool for resolving civil disputes, and particularly as a substitute for court decisions, some have questioned mediation\u27s ability to assure fairness of process and outcome. Others have argued that the main strength of mediation lies in the power it gives the parties to invent their own approach to resolving their dispute, leaving little room for mediators to impose their own notions of fairness on the process. This article examines the extent to which mediators have an obligation to address issues of fairness in the processes they manage. Through a functional and context-based analysis of mediation, the author proposes a problem-solving approach to resolving fairness concerns

A comparison of different pre-lysis methods and extraction kits for recovery of Stretococcus agalacticae (Lancefield group B Streptococcus) DNA from whole blood

Sub-optimal recovery of bacterial DNA from whole blood samples can limit the sensitivity of molecular assays to detect pathogenic bacteria. We compared 3 different pre-lysis protocols (none, mechanical pre-lysis and achromopeptidasepre-lysis) and 5 commercially available DNA extraction platforms for direct detection of Group B Streptococcus (GBS) in spiked whole blood samples, without enrichment culture. DNA was extracted using the QIAamp Blood Mini kit (Qiagen), UCP Pathogen Mini kit (Qiagen), QuickGene DNA Whole Blood kit S (Fuji), Speed Xtract Nucleic Acid Kit 200 (Qiagen) and MagNA Pure Compact Nucleic Acid Isolation Kit I (Roche Diagnostics Corp). Mechanical pre-lysis increased yields of bacterial genomic DNA by 51.3 fold (95% confidence interval; 31.6–85.1, p < 0.001) and pre-lysis with achromopeptidase by 6.1 fold (95% CI; 4.2–8.9, p < 0.001), compared with no pre-lysis. Differences in yield dueto pre-lysis were 2–3 fold larger than differences in yield between extraction methods. Including a pre-lysis step can improve the limits of detection of GBS using PCR or other molecular methods without need for culture