[a] 1IntroductionInterest in real-timem onitoring of biochemical parameters using wearable/on-body sensors is ar apidly growing area of research [1],d ue in partt ot he convergence of interest of major economic sectors in applications based on new types of information. ICT companies like Apple and Googleare exploring ways to access biochemical information as am eans to move beyond the mature sensor technologies currently employed in exercise and sports APPs that track ausers location,body movements,temperature, energy expenditurea nd so on. These are typically based on physical transducers or imaging technologies embedded within wristbands or smart phones.H owever, employings imilar approaches that depend on time-series data to the domain of biochemical sensing is much more difficult, due to the complexc hallenges associated with access to representative samples (typically ab ody fluid) and the less predictable behavioro fc hemical sensors and biosensors over time.Since the exciting developments of the 1980s,t he application of biochemical sensing to real-timem onitoring of the human condition has scarcely advanced in terms of the performance of the sensors.T oday,t he use-model has almost entirely shifted awayf rom the early over-optimistic promise of implantable sensorst hat are in continuous contact with blood[ 2],t od evices sitedo utside the body that somehow can access ani nformation rich body fluid, like sweat [3] [4] or saliva [5].F or the past several decades,t he predominantu se model for health related diagnostics has been the disposable single-shot sensorc ombined with af inger prick access to blood samples.E xamples of use modelst hat involve real-time monitoring of body fluids (albeit over relatively short periods typically at most up to several days) include the integration of biosensors with contact lenses that can sample and report on the composition of ocular fluid,w hich is in turn reflective of the systemic blood composition [6].P erhapst he bestknown exampleo ft his is the collaborative ventureb etween Google and Novartis [7],b ased on Parviss work Abstract:Aplatform for harvesting and analysingt he sodium content of sweat in real time is presented. One is a watch format in which thes ampling and fluidic system,e lectrodes,c ircuitry and battery are arranged vertically,w hile in the other pod format, the electronics and battery components,a nd the fluidics electrodes are arranged horizontally.T he platformsa re designedt ob e securely attached to the skin using av elcros trap.S weat enters into the device through as ampling orifice and passes over solid-state sodium-selective and reference electrodes and into as torage area containing ah igh capacity adsorbent material. Thel iquid movement is entirely drivenb yc apillary action, and the flow rate through the device can be mediated through variation of the width of af luidic channel linking the electrodes to the sample storage area. Changing the width dimension through7 50, 500 and 250 mmp roduces flow rates of 38.20, 21.48 and 6.61 mL/min...

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A wearable device for real-time monitoring of sodium levels in sweat is presented.

Mortality rates of up to 50% have been reported after liver failure due to drug-induced hepatotoxicity and certain viral infections (Gao et al. 2008). These adverse conditions frequently affect HIV and tuberculosis patients on regular medication in resource-poor settings. Here, we report full integration of sample preparation with read-out of a 5-parameter liver assay panel (LAP) on a portable, easy-to-use, fast and costefficient centrifugal microfluidic analysis system (CMAS). Our unique, dissolvable-film based centrifugopneumatic valving was employed to provide sample-to-answer fashion automation for plasma extraction (from finger-prick of blood), metering and aliquoting into separate reaction chambers for parallelized colorimetric quantification during rotation. The entire LAP completes in less than 20 minutes while using only a tenth the reagent volumes when compared with standard hospital laboratory tests. Accuracy of in-situ liver function screening was validated by 96 separate tests with an average coefficient of variance (CV) of 7.9% compared to benchtop and hospital lab tests. Unpaired two sample statistical t-tests were used to compare the means of CMAS and benchtop reader, on one hand; and CMAS and hospital tests on the other. The results demonstrate no statistical difference between the respective means with 94% and 92% certainty of equivalence, respectively. The portable platform thus saves significant time, labour and costs compared to established technologies, and therefore comply with typical restrictions on lab infrastructure, maintenance, operator skill and costs prevalent in many field clinics of the developing world. It has been successfully deployed in a centralised lab in Nigeria. IntroductionLiver is the largest solid organ in the body and is largely responsible for metabolism and detoxification. (Gao et al. 2008) Liver function tests are widely used in clinical chemistry to assess therapeutic effects and potential medication-induced liver damage, especially when taking medications for HIV, tuberculosis and cancer. (Landis et al. 2013;Rahmioglu et al. 2009; Vella et al. 2012) Literature reports suggest that a mortality rate of 2 -28% can be linked with medication-induced liver damage. (Vella et al. 2012) As a result, monitoring of liver function when on certain medications has become common practice in developed countries but can be expensive in poor resource areas. This has prompted local governments and international funding agencies to set up centralised laboratories for liver function monitoring tests especially for HIV patients. Nonetheless, transport logistics and accessibility remains a significant challenge for the majority of these patients. Thus it is very important to develop portable point-of-care (PoC) devices that could be used for liver function screening in the field. Currently, there are only a handful of sample-to-answer PoC devices available for deployment in the field. Recently, Vella et al.(Vella et al. 2012) demonstrated an innovative micropatterned paper device fo...