Two Solutions of Soil Moisture Sensing with RFID for Landslide Monitoring.

Two solutions for UHF RFID tags for soil moisture sensing were designed and are described in this paper. In the first, two conventional tags (standard transponders) are employed: one, placed close to the soil surface, is the sensor tag, while the other, separated from the soil, is the reference for system calibration. By transmission power ramps, the tag's turn-on power levels are measured and correlated with soil condition (dry or wet). In the second solution, the SL900A chip, which supports up to two external sensors and an internal temperature sensor, is used. An interdigital capacitive sensor was connected to the transponder chip and used for soil moisture measurement. In a novel design for an UHF RFID tag the sensor is placed below the soil surface, while the transponder and antenna are above the soil to improve communication. Both solutions are evaluated practically and results show the presence of water in soil can be remotely detected allowing for their application in landslide monitoring.

Unlocking the full potential of digital endpoints for decision making: a novel modular evidence concept enabling re-use and advancing collaboration.

INTRODUCTION: Over the last decade increasing examples indicate opportunities to measure patient functioning and its relevance for clinical and regulatory decision making via endpoints collected through digital health technologies. More recently, we have seen such measures support primary study endpoints and enable smaller trials. The field is advancing fast: validation requirements have been proposed in the literature and regulators are releasing new guidances to review these endpoints. Pharmaceutical companies are embracing collaborations to develop them and working with academia and patient organizations in their development. However, the road to validation and regulatory acceptance is lengthy. The full value of digital endpoints cannot be unlocked until better collaboration and modular evidence frameworks are developed enabling re-use of evidence and repurposing of digital endpoints. AREAS COVERED: This paper proposes a solution by presenting a novel modular evidence framework -the Digital Evidence Ecosystem and Protocols (DEEP)- enabling repurposing of measurement solutions, re-use of evidence, application of standards and also facilitates collaboration with health technology assessment bodies. EXPERT OPINION: The integration of digital endpoints in healthcare, essential for personalized and remote care, requires harmonization and transparency. The proposed novel stack model offers a modular approach, fostering collaboration and expediting the adoption in patient care.

A meta-analysis to determine the effect of preinjury antiplatelet agents on mortality in patients with blunt head trauma.

INTRODUCTION: Anticoagulation abnormalities have been recognized for several decades as potential risk factors for increasing the risk of traumatic intracranial haemorrhage in patients with blunt head trauma. The potential increased risk of death as a consequence has not been fully evaluated. The aim of the study was to perform a meta-analysis in order to evaluate based upon the current level of evidence whether the use of pre-injury aspirin or clopidogrel increases the risk of mortality in patients with blunt head trauma. METHODS: The databases Medline and EMBASE were searched via the Ovid interface. The Medline database was also searched using the PubMed interface. Case control studies or nested case control studies were identified comparing mortality rates on patients with blunt head trauma in patients on aspirin or clopidogrel against patients not on antiplatelet agents. RESULTS: Five studies in total were identified as suitable for the meta-analysis. Four of these studies were suitable for the aspirin meta-analysis and four for the clopidogrel meta-analysis. The common odds ratio for the aspirin meta-analysis using the Random Effects model was found to be 2.435 (95% CI: 0.637-9.314). Significant heterogeneity was present I(2) = 79.521. The common odds ratio for the clopidogrel meta-analysis using the Random Effects model was found to be 1.554 (95% CI: 0.320-7.536). Significant heterogeneity was present I(2) = 69.090. CONCLUSIONS: In summary, this meta-analysis showed a slight increased risk of death in patients with blunt head trauma who were taking pre-injury antiplatelet agents although the results did not reach statistical significance. In view of the small number of low level studies from which this meta-analysis is based, further work is required in this area.

An analysis of predictive markers for intracranial haemorrhage in warfarinised head injury patients.

INTRODUCTION: Minor head injury in older patients on warfarin may present in a variety of ways that often fall outside the remit of conventional guidelines. The aim of this study was to determine the relative risks for intracranial haemorrhage (ICH) in patients with subtherapeutic, therapeutic and supratherapeutic INR levels, in addition to the relative risks for the common symptoms at presentation. METHODS: The notes were retrospectively reviewed of all patients who had a CT scan requested by the emergency department over a 2-year period (January 2008 to December 2009) and from these warfarinised head injuries were identified. RESULTS: 82 warfarinised head injury patients were identified from 3338 requested CT scans. 12 of these patients (15%) had evidence of ICH on the CT. 72 patients had their INR checked (88%) and the RR of ICH for the INR subgroups were calculated: INR <2 (RR 1.89; 95% CI 0.65 to 5.55); INR 2-3 (RR 0.84; 95% CI 0.27 to 2.64); and INR >3 (RR 0.53; 95% CI 0.13 to 2.29). The greatest proportion of those with ICH (42%) had a subtherapeutic INR. 2 out of the 12 patients (17%) were found to have intracranial bleeding despite not meeting the criteria for a CT scan according to the NICE guidelines. CONCLUSION: The results of the INR subgroup analysis suggest that a subtherapeutic INR may not be protective against ICH in patients with minor head injury.

A comparison of conductive ink usage optimization techniques used in fabrication of epidermal UHF radio frequency identification tags for medical and sensing applications.

The aim of this work is to assess the performance of various inkjet printing techniques. These techniques are aimed at optimizing the volume of conductive ink used in the fabrication of inkjet printed Radio Frequency Identification tags. It is also possible that they can be used in fabricating other electronic and electromagnetic devices and structures. Three ink optimization approaches were examined viz. gridded (meshed) designs, conductive area trimming and selective ink deposition. The volume of conductive ink utilized in tag fabrication and the measured on-body (forearm) read range of the tag were used to develop a figure of merit which determined the best printing approach. Although the longest read range was obtained from the tag with 48% conductive area trimming (Trim 1), the best figure of merit, that is, the tag with the best balance between measured read range and utilized conductive ink, was obtained from the tag that had its surface area trimmed by 65% (Trim 2). It is however suggested that optimum use of conductive ink would be achieved with a combination of 65% surface area trimming and selective ink deposition technique.

A meta-analysis to determine the effect of anticoagulation on mortality in patients with blunt head trauma.

INTRODUCTION: Patients on warfarin are increasingly common in an ageing population. Previously published case series and cohort studies have resulted in conflicting conclusions with regard to the risk of fatal intracranial haemorrhage. The aim of this study was to undertake a meta-analysis in order to compare the mortality rate of anticoagulated head injured patients against the mortality rate of head injured patients not on coumarin anticoagulation. METHODS: The databases Medline and EMBASE were searched via the ovid interface. The initial search strategy returned 364 results. A second search was performed using Pubmed to identify possible abstracts missed by the first search. Forty-seven full articles were reviewed if the abstract suggested that they were either case control studies or nested case control studies comparing the mortality rate of anticoagulated head injured patients against the mortality rate of head injured patients not on coumarin anticoagulation. RESULTS: Eleven papers were identified, which met the criteria for the meta-analysis. Despite the heterogeneity between the studies (Q test: 27.421, 10 DF, P = 0.002), the fixed effects model may be the preferred model based on the fact that 10 out of the 11 studies had an odds ratio greater than one. The fixed effects model produced a common odds ratio for death in anticoagulated patients with blunt head trauma of 2.008 (95% CI 1.634 - 2.467). CONCLUSIONS: The results of this meta-analysis has shown that the cohort of patients who are anticoagulated and suffer blunt head trauma appear to have an increased risk of death compared to a similar cohort of head injured patients who are not anticoagulated.

A retrospective cohort study to re-evaluate clinical correlates for intracranial injury in minor head injury.

INTRODUCTION: The aim of this study was to determine the Relative Risk (RR) ratios for common clinical correlates in adult patients with minor head injury in a cohort of patients in which loss of consciousness (LOC) and post-traumatic amnesia (PTA) were not the only entry criteria for CT scanning. METHODS: The computerised CT request notes were reviewed on all patients who underwent a CT head scan with a minor head injury over a 1-year period (January 2009-December 2009). The clinical signs and symptoms at presentation were extracted from the request notes and the RR ratios were calculated for five clinical correlates: LOC, PTA, vomiting, nausea and headache. RESULTS: 456 Glasgow coma scale (GCS) 15 patients underwent CT scanning during the period January 2009-December 2009. 55 of the 456 patients had positive CT findings (12%). 270 patients (59%) of the GCS 15 cohort had neither LOC nor PTA and of this subgroup 27 had positive scans. LOC was the only clinical correlate in which the RR reached statistical significance; RR 2.0930 (95% CI 1.25 to 3.50). However, vomiting accounted for four cases, headache for four cases and nausea for no cases. CONCLUSIONS: Using LOC or PTA as the principal entry criterion for CT scanning may result in a significant number of patients with traumatic intracranial injury being missed. Using a less stringent approach still achieved an acceptable CT abnormality rate.

Synthesis and structure-activity relationships of 4-pyridones as potential antimalarials.

A series of diaryl ether substituted 4-pyridones have been identified as having potent antimalarial activity superior to that of chloroquine against Plasmodium falciparum in vitro and murine Plasmodium yoelii in vivo. These were derived from the anticoccidial drug clopidol through a systematic study of the effects of varying the side chain on activity. Relative to clopidol the most active compounds show >500-fold improvement in IC50 for inhibition of P. falciparum in vitro and about 100-fold improvement with respect to ED50 against P. yoelii in mice. These compounds have been shown elsewhere to act selectively by inhibition of mitochondrial electron transport at the cytochrome bc1 complex.

An Exploration of Behind-the-Ear ECG Signals From a Single Ear Using Inkjet Printed Conformal Tattoo Electrodes.

Wearable sensors placed behind-the-ear are emerging as being very promising for unobtrusive long term monitoring. Factors such as gait, electroencephalography (EEG), and ballistocardiography (BCG) can all be measured from behind-the-ear in a socially acceptable hearing aid based form factor. Previous works have investigated the recording of electrocardiography (ECG) from the ear, but generally with one electrode placed some distance away from the ear itself. This paper uses recently introduced tattoo electrodes to investigate whether ECG components can indeed be measured from behind a single ear. Compared to a reference photophelsmography (PPG) device we show that the fundamental heart beat frequency is present in behind-the-ear ECG only in half of the cases considered. In contrast the second harmonic is present in all records and could allow the extraction of heart rate to within a few beats-per-minute accuracy. Further signal processing work is required to allow the automated extraction of this, particularly when working with short time windows of data, but our results characterize the signal and demonstrate the principle of behind-the-ear ECG collected from a single ear.

Effect of skin dielectric properties on the read range of epidermal ultra-high frequency radio-frequency identification tags.

This Letter presents an investigation of the effect of human tissue conductivity and permittivity on the performance of epidermal transfer tattoo ultra-high frequency radio-frequency identification (RFID) tags. The measurements were carried out on 20 individuals and the variations in the measured dielectric properties correlate well with variations in the measured tag read range on the individuals and to a lesser extent with their body mass index values. Simulation results also showed the effects of permittivity and conductivity on the designed resonance frequency of the RFID tag.

Conformal electronics for longitudinal bio-sensing in at-home assistive and rehabilitative devices.

Wearable electronics are revolutionizing personalized and preventative healthcare by allowing the easy, unobtrusive, and long term monitoring of a range of body parameters. Conformal electronics which attach directly to the skin in a very robust and long term manner are envisioned as the next generation of highly portable miniaturized computing devices, beyond wearables. In this paper we overview the state-of-the-art in conformal electronics created using silver nanoparticle inkjet printed techniques for home assistive and rehabilitative devices. The barriers to wider adaption, particularly the challenges of high performance antenna design when placed close to the body, are discussed in detail.

Passive wireless tags for tongue controlled assistive technology interfaces.

Tongue control with low profile, passive mouth tags is demonstrated as a human-device interface by communicating values of tongue-tag separation over a wireless link. Confusion matrices are provided to demonstrate user accuracy in targeting by tongue position. Accuracy is found to increase dramatically after short training sequences with errors falling close to 1% in magnitude with zero missed targets. The rate at which users are able to learn accurate targeting with high accuracy indicates that this is an intuitive device to operate. The significance of the work is that innovative very unobtrusive, wireless tags can be used to provide intuitive human-computer interfaces based on low cost and disposable mouth mounted technology. With the development of an appropriate reading system, control of assistive devices such as computer mice or wheelchairs could be possible for tetraplegics and others who retain fine motor control capability of their tongues. The tags contain no battery and are intended to fit directly on the hard palate, detecting tongue position in the mouth with no need for tongue piercings.

Inkjet printed ECG electrodes for long term biosignal monitoring in personalized and ubiquitous healthcare.

This paper investigates the performance of inkjet printed electrodes for electrocardiogram (ECG) monitoring in personalized and ubiquitous healthcare. As a rapid prototyping, additive manufacturing approach, inkjet printing can allow personalization of electrode sizes and shapes and can be used with a range of substrates to achieve good long term connections to the skin. We compare the performance of two types of inkjet electrodes printed using different substrates. Results demonstrate that both new electrodes can record ECG information, with comparable signal-to-noise ratios to conventional Ag/AgCl electrodes. The time-frequency decomposition of the collected signals is also explored.

Smart radio-frequency identification tag for diaper moisture detection.

A passive smart tag is described that responds to dampness in diapers once a pre-defined threshold value is reached. A high-frequency (HF) system at 13.56 MHz is used as this allows operation through water or human tissues with less absorption that would occur for an ultra-HF signal. A circular spiral coil and swelling substrate facilitate a reaction to dampness that can be detected without contact to the diaper wearer. A prototype design is simulated and measured results are provided together with a demonstration of a tag integrated into a worn diaper.

A meta-analysis of clinical correlates that predict significant intracranial injury in adults with minor head trauma.

Previous studies have resulted in conflicting results regarding the predictive effect of various clinical symptoms, signs, and plain imaging for intracranial pathology in adults with minor head injury. We sought to perform a meta-analysis of the literature to assess the significance of these factors for the prediction of intracranial hemorrhage (ICH). The literature was searched using Medline, Embase, Experts, and the Grey literature. Reference lists of major guidelines were crosschecked. Included were control or nested case control studies of patients attending hospital with head injury that recorded clinical correlates relating to the outcome variable of presence or absence of ICH. The common relative risk ratio was calculated using the Mantel-Haenszel test with a pooled estimate. Thirty-five papers containing 83,636 patients were included in the meta-analysis after systematic review of the literature. Relative risk ratios were calculated for 23 clinical correlates from the history, the mechanism of injury, and the examination. In addition, adjusted relative risks were presented for those variables that showed significant heterogeneity across studies. Reasons for the heterogeneity are discussed. This study has determined the relative risks of 23 clinical variables that may predict the presence of an ICH in patients after minor head injury. These risks should prove invaluable to clinicians for the assessment of individual patients as well as the assessment of guidelines presented for the management of minor head injuries.

A meta-analysis to determine the effect on survival of platelet transfusions in patients with either spontaneous or traumatic antiplatelet medication-associated intracranial haemorrhage.

OBJECTIVES: The aim of this study was to evaluate by meta-analysis the current level of evidence in order to establish the impact of a platelet transfusion on survival in patients on pre-injury antiplatelet agents who sustain an intracranial haemorrhage (either spontaneous or traumatic). DESIGN: This was a meta-analysis; the MEDLINE Database was searched using the PubMed interface and the Ovid interface. CINAHL and EMBASE Databases were also searched. The search was performed to identify randomised controlled trials (RCT)'s case-controlled studies or nested case-controlled studies. Comparing the outcome (death or survival) of patients with intracranial haemorrhage (ICH) and pre-injury antiplatelet agents who received a platelet transfusion against a similar cohort of patients who did not receive a platelet transfusion. RESULTS: 499 citations were obtained from the PubMed search. 31 full articles were reviewed from 34 abstracts. 6 studies were found suitable for the meta-analysis. No randomised controlled studies were identified. 2 of the six studies were in patients with spontaneous ICH. The remaining four studies were in patients with traumatic intracranial haemorrhage. Significant heterogeneity was present between the studies, I(2)=58.276. The random effects model was therefore the preferred model, this produced a pooled OR for survival of 0.773 (95% CI 0.414 to 1.442). CONCLUSIONS: The results of this meta-analysis has shown, based upon six small studies, that there was no clear benefit in terms of survival in the administration of a platelet transfusion to patients with antiplatelet-associated ICH. Further work is required in order to establish any potential benefit in the administration of a platelet transfusion in patients with spontaneous or traumatic intracranial haemorrhage who were on pre-injury antiplatelet agents.