Feasibility and Usability Aspects of Continuous Remote Monitoring of Health Status in Palliative Cancer Patients Using Wearables.

BACKGROUND: Mobile health is a promising strategy aiming to anticipate and prevent the deterioration of health status in palliative cancer patients. A prerequisite for successful implementation of this technology into clinical routine is a high level of usability and acceptance of devices. OBJECTIVES: We aimed to evaluate feasibility as well as patients' acceptance of remote monitoring using wearables in palliative cancer patients. METHODS: In this prospective single-center observational feasibility study, 30 cancer patients treated with palliative intent in an inpatient setting with an estimated life expectancy of >8 weeks and <12 months were provided with a smartphone including a pre-installed "Activity Monitoring" app and a sensor-equipped bracelet and monitored over a period of 12 weeks starting at discharge from hospital. We report detailed feasibility and usability aspects and comment on patients' acceptance of the wearables. RESULTS: Between February 2017 and May 2018 a total of 30 patients were included in the study. From these, 25 participants (83%) completed the whole study period. On average, the bracelet was worn on 53% and smartphone used on 85% of the study days. The completion rate of daily digital questionnaires for subjective ratings (pain and distress scale) was 73%, and 28 patients were able to handle the wearables and to operate the app without major problems. Use of the bracelet was low during the night hours, with a wearing time of 1.7% of all night hours (8 p.m. to 8 a.m.). CONCLUSIONS: Remote monitoring of health care status in palliative cancer patients with a limited life expectancy is feasible and patients are able to handle the smartphone and the sensor-equipped bracelet. Feedback towards use of this monitoring system was mostly positive.

Photo-Induced Room-Temperature Gas Sensing with a-IGZO Based Thin-Film Transistors Fabricated on Flexible Plastic Foil.

We present a gas sensitive thin-film transistor (TFT) based on an amorphous Indium-Gallium-Zinc-Oxide (a-IGZO) semiconductor as the sensing layer, which is fabricated on a free-standing flexible polyimide foil. The photo-induced sensor response to NO2 gas at room temperature and the cross-sensitivity to humidity are investigated. We combine the advantages of a transistor based sensor with flexible electronics technology to demonstrate the first flexible a-IGZO based gas sensitive TFT. Since flexible plastic substrates prohibit the use of high operating temperatures, the charge generation is promoted with the help of UV-light absorption, which ultimately triggers the reversible chemical reaction with the trace gas. Furthermore, the device fabrication process flow can be directly implemented in standard TFT technology, allowing for the parallel integration of the sensor and analog or logical circuits.

eHealth and mHealth interventions in the treatment of fatigued cancer survivors: A systematic review and meta-analysis.

OBJECTIVES: To (1) evaluate existing eHealth/mHealth interventions developed to help manage cancer-related fatigue (CRF); and (2) summarize the best available evidence on their effectiveness. METHODS: A comprehensive literature search of PubMed, MEDLINE, EMBASE, and the Cochrane Library up to November 2016 was conducted. Study outcomes were extracted, tabulated, and summarized. Random effects meta-analyses were conducted for the primary outcome (fatigue), and the secondary outcomes quality of life and depression, yielding pooled effect sizes (r), and 95% confidence intervals (CI). RESULTS: For eHealth interventions, our search of published papers identified 9 completed studies and 6 protocols for funded projects underway. No studies were identified for mHealth interventions that met our inclusion criteria. A meta-analysis of the 9 completed eHealth studies revealed a statistically significant beneficial effect of eHealth interventions on CRF (r = .27, 95% CI [.1109 - .4218], P < 0.01). Therapist-guided eHealth interventions were more efficacious then self-guided interventions (r = .58, 95% CI: [.3136 - .5985, P < 0.001). Small to moderate therapeutic effects were also observed for HRQoL (r = .17, 95% CI [.0384 - .3085], P < 0.05) and depression (r = .24, 95% CI [.1431 - .3334], P < 0.001). CONCLUSIONS: eHealth interventions appear to be effective for managing fatigue in cancer survivors with CRF. Continuous development of eHealth interventions for the treatment of CRF in cancer survivors and their testing in long-term, large-scale efficacy outcome studies is encouraged. The degree to which mHealth interventions can change CRF in cancer survivors need to be assessed systematically and empirically.

Evaluation of a textile-based near infrared spectroscopy system in calf muscle oxygenation measurements.

We recently introduced a novel textile-based NIRS sensor (TexNIRS). Here, we evaluate TexNIRS in ten subjects (16 legs, age 28.5 ± 2.32 years, adipose tissue thickness (ATT) 4.17 ± 1.71 mm). Three venous occlusions at 50 mmHg were performed on their calf muscle. After 3 min of occlusion, oxy/deoxy hemoglobin concentration ([O2Hb], [HHb]) changes were 3.71 ± 1.89/1.79 ± 1.08 µM; venous oxygen saturation (SvO2) was 75 ± 9.7 %, oxygen consumption (VO2) was 0.02 ± 0.01 mL/100 g/min, hemoglobin flow (HF) was 0.93 ± 0.48 µmol/100 mL/min, and blood flow (BF) was 2.01 ± 1.04 mL/100 mL/min. Our results are in good agreement with the literature, but the TexNIRS enables a much higher level of comfort.

Textile integrated sensors and actuators for near-infrared spectroscopy.

Being the closest layer to our body, textiles provide an ideal platform for integrating sensors and actuators to monitor physiological signals. We used a woven textile to integrate photodiodes and light emitting diodes. LEDs and photodiodes enable near-infrared spectroscopy (NIRS) systems to monitor arterial oxygen saturation and oxygenated and deoxygenated hemoglobin in human tissue. Photodiodes and LEDs are mounted on flexible plastic strips with widths of 4 mm and 2 mm, respectively. The strips are woven during the textile fabrication process in weft direction and interconnected with copper wires with a diameter of 71 µm in warp direction. The sensor textile is applied to measure the pulse waves in the fingertip and the changes in oxygenated and deoxygenated hemoglobin during a venous occlusion at the calf. The system has a signal-to-noise ratio of more than 70 dB and a system drift of 0.37% ± 0.48%. The presented work demonstrates the feasibility of integrating photodiodes and LEDs into woven textiles, a step towards wearable health monitoring devices.

Monitoring motor capacity changes of children during rehabilitation using body-worn sensors.

BACKGROUND: Rehabilitation services use outcome measures to track motor performance of their patients over time. State-of-the-art approaches use mainly patients' feedback and experts' observations for this purpose. We aim at continuously monitoring children in daily life and assessing normal activities to close the gap between movements done as instructed by caregivers and natural movements during daily life. To investigate the applicability of body-worn sensors for motor assessment in children, we investigated changes in movement capacity during defined motor tasks longitudinally. METHODS: We performed a longitudinal study over four weeks with 4 children (2 girls; 2 diagnosed with Cerebral Palsy and 2 with stroke, on average 10.5 years old) undergoing rehabilitation. Every week, the children performed 10 predefined motor tasks. Capacity in terms of quality and quantity was assessed by experts and movement was monitored using 10 ETH Orientation Sensors (ETHOS), a small and unobtrusive inertial measurement unit. Features such as smoothness of movement were calculated from the sensor data and a regression was used to estimate the capacity from the features and their relation to clinical data. Therefore, the target and features were normalized to range from 0 to 1. RESULTS: We achieved a mean RMS-error of 0.15 and a mean correlation value of 0.86 (p < 0.05 for all tasks) between our regression estimate of motor task capacity and experts' ratings across all tasks. We identified the most important features and were able to reduce the sensor setup from 10 to 3 sensors. We investigated features that provided a good estimate of the motor capacity independently of the task performed, e.g. smoothness of the movement. CONCLUSIONS: We found that children's task capacity can be assessed from wearable sensors and that some of the calculated features provide a good estimate of movement capacity over different tasks. This indicates the potential of using the sensors in daily life, when little or no information on the task performed is available. For the assessment, the use of three sensors on both wrists and the hip suffices. With the developed algorithms, we plan to assess children's motor performance in daily life with a follow-up study.

In tube integrated electronic nose system on a flexible polymer substrate.

The fabrication of electronic devices, such as gas sensors on flexible polymer substrates, enables the use of electronics in applications where conventional devices on stiff substrates could not be used. We demonstrate the development of a new intra-tube electronic-nose (e-nose) gas sensor device with multiple sensors fabricated and integrated on a flexible substrate. For this purpose, we developed a new method of fabricating a sensor array of four gas sensors on a flexible polymer substrate. The method allowed the use of lithography techniques to pattern different polymers with a broad range of solubility parameters. Conductive polymer composites were used as a gas sensitive layer due to the high stretchability of the material. Each of the 30 e-nose devices on one substrate was designed to fit on a polymer strip with a width of 2 mm. A single e-nose strip was successfully integrated into the inlet tube of a gas-measurement apparatus with an inner-tube diameter of 3 mm. Using the e-nose, we were able to differentiate between four different volatile solvent vapors. The tube-integrated e-nose outperformed a chamber-integrated e-nose of the same type in terms of response time and flow-rate influences. The sensor array inside the tube showed a faster response time and detected short pulses of analyte exposure compared to the same sensor array outside of the tube. We measured gas flow rates from 1,000 to 30 sccm without significant changes in sensor performance using this intra-tube e-nose prototype. The tube could be bent to radii < 15 mm with a sensor performance similar to an unbent sensor.

Monitoring stage fright outside the laboratory: an example in a professional musician using wearable sensors.

We implemented and tested a wearable sensor system to measure patterns of stress responses in a professional musician under public performance conditions. Using this sensor system, we monitored the cellist's heart activity, the motion of multiple body parts, and their gradual changes during three repeated performances of a skill-demanding piece in front of a professional audience. From the cellist and her teachers, we collected stage fright self-reports and performance ratings that were related to our sensor data analysis results. Concomitant to changes in body motion and heart rate, the cellist perceived a reduction in stage fright. Performance quality was objectively improved, as technical playing errors decreased throughout repeated renditions. In particular, from performance 1 to 3, the wearable sensors measured a significant increase in the cellist's bowing motion dynamics of approximately 6% and a decrease in heart rate. Bowing motion showed a marginal correlation to the observed heart rate patterns during playing. The wearable system did not interfere with the cellist's performance, thereby allowing investigation of stress responses during natural public performances.

Mobile Health Technologies for Continuous Monitoring of Cancer Patients in Palliative Care Aiming to Predict Health Status Deterioration: A Feasibility Study.

Background: Unplanned readmissions or emergency visits (EVs) after discharge from hospital are frequent in patients in palliative care. Strategies to anticipate and prevent rapid deterioration of health are needed. Objective: Assessing feasibility and predictive ability of remote monitoring using wearables. Design: Prospective observational feasibility study in a single center. Setting/Subjects: Thirty cancer patients with an estimated life expectancy of >8 weeks to <12 months, aged >18 years and being discharged from inpatient to outpatient care were included. Measurements: Patients were provided with a smartphone, including the preinstalled "Activity Monitoring" application and a sensor-equipped bracelet. Follow-up was 12 weeks. Both devices recorded several features (e.g., vital signs). Visual analog scale (VAS) for pain and distress was reported once daily and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30) once weekly. Statistical methods were applied to explore relationship between sensor data, self-reports, and EVs or readmissions or death. Results: Between February 2017 and May 2018, 30 patients were included. Twenty-five of 30 participants (83%) completed 12 weeks of follow-up. On average, bracelet was worn on 53% and smartphone on 85% of study days. Completion rate of daily digital questionnaires for subjective ratings was 73%. Eight unplanned hospital readmissions occurred. Ratings of pain, distress, and QLQ-C30 scores were not associated with readmission, whereas resting heart rate, resting heart rate variability, as well as speed of steps differed significantly in patients with and without readmission. Conclusions: Monitoring of palliative cancer patients using wearables is feasible. First results indicate that mobile health features might be promising biomarkers to predict unplanned readmissions.

On the Bending and Stretching of Liquid Metal Receive Coils for Magnetic Resonance Imaging.

The eGaIn coil on neoprene demonstrated in this paper presents a stretchable radio frequency receive coil for magnetic resonance imaging (MRI). The coil with dimensions [Formula: see text] is tuned to resonate at 128 MHz for 3 T MRI. We investigate the effect of stretching (up to 40% strain) and bending (50 mm radius of curvature) of the coil on the coil's resistance and resonance frequency. Measurements and simulations show a decrease in resonance frequency of 2.5 MHz per 10% strain. The higher resistivity of liquid metal compared to copper reduces the SNR of MRI scans by 34%; therefore, a tradeoff between flexibility and performance remains. Nevertheless, we have successfully performed MRI scans with the liquid metal coil.

Automatic Resonance Frequency Retuning of Stretchable Liquid Metal Receive Coil for Magnetic Resonance Imaging.

Stretchable magnetic resonance (MR) receive coils show shifts in their resonance frequency when stretched. An in-field receiver measures the frequency response of a stretchable coil. The receiver and coil are designed to operate at 128 MHz for a 3T MR scanner. Based on the measured frequency response, we are able to detect the changes of the resonance frequency of the coil. We show a proportional-integral-derivative controller that tracks the changes in resonance frequency and retunes the stretchable coil. The settling time of the control loop is less than 3.8ms. The retuning system reduces the loss in signal-to-noise ratio of phantom images from 1.6 dB to 0.3 dB, when the coil is stretched by 40% and the coil is retuned to 128 MHz.

Recognition of dietary activity events using on-body sensors.

OBJECTIVE: An imbalanced diet elevates health risks for many chronic diseases including obesity. Dietary monitoring could contribute vital information to lifestyle coaching and diet management, however, current monitoring solutions are not feasible for a long-term implementation. Towards automatic dietary monitoring, this work targets the continuous recognition of dietary activities using on-body sensors. METHODS: An on-body sensing approach was chosen, based on three core activities during intake: arm movements, chewing and swallowing. In three independent evaluation studies the continuous recognition of activity events was investigated and the precision-recall performance analysed. An event recognition procedure was deployed, that addresses multiple challenges of continuous activity recognition, including the dynamic adaptability for variable-length activities and flexible deployment by supporting one to many independent classes. The approach uses a sensitive activity event search followed by a selective refinement of the detection using different information fusion schemes. The method is simple and modular in design and implementation. RESULTS: The recognition procedure was successfully adapted to the investigated dietary activities. Four intake gesture categories from arm movements and two food groups from chewing cycle sounds were detected and identified with a recall of 80-90% and a precision of 50- 64%. The detection of individual swallows resulted in 68% recall and 20% precision. Sample-accurate recognition rates were 79% for movements, 86% for chewing and 70% for swallowing. CONCLUSIONS: Body movements and chewing sounds can be accurately identified using on-body sensors, demonstrating the feasibility of on-body dietary monitoring. Further investigations are needed to improve the swallowing spotting performance.

Sensor for Measuring Strain in Textile.

In this paper a stain sensor to measure large strain (80%) in textiles is presented. It consists of a mixture of 50wt-% thermoplastic elastomer (TPE) and 50wt-% carbon black particles and is fiber-shaped with a diameter of 0.315mm. The attachment of the sensor to the textile is realized using a silicone film. This sensor configuration was characterized using a strain tester and measuring the resistance (extension-retraction cycles): It showed a linear resistance response to strain, a small hysteresis, no ageing effects and a small dependance on the strain velocity. The total mean error caused by all these effects was +/-5.5% in strain. Washing several times in a conventional washing machine did not influence the sensor properties. The paper finishes by showing an example application where 21 strain sensors were integrated into a catsuit. With this garment, 27 upper body postures could be recognized with an accuracy of 97%.

Evaluation of Piano Key Vibrations Among Different Acoustic Pianos and Relevance to Vibration Sensation.

Recent studies suggest that vibration of piano keys affect the perceived quality of the instrument, as well as the dynamic control and timing in piano playing. However, the time signals of piano key vibrations and its physical properties have not been analyzed and compared to the threshold of vibration sensation in a real-life playing situation yet. This study investigates piano key vibrations and explores the diversity of vibrations among different pianos with a laser Doppler vibrometer. A pianist was performing single keystrokes, note sequences, and a music piece excerpt on four concert grand pianos, five grand pianos, and two upright pianos. The measurements showed peak displacement levels up to 80 m and the frequency spectrum of the vibrations is dominated by frequencies lower than 500 Hz. Finally, a frequency weighting filter is introduced to show that vibration displacement time signals exceed the threshold of human vibration sensation for all evaluated instruments, when a note sequence is played in the bass to mid range with a single hand at forte level. The conducted experiments demonstrate that the vibration characteristics vary distinctively among the investigated pianos.

Ge2Sb2Te5 p-Type Thin-Film Transistors on Flexible Plastic Foil.

In this work, we show the performance improvement of p-type thin-film transistors (TFTs) with Ge 2 Sb 2 Te 5 (GST) semiconductor layers on flexible polyimide substrates, achieved by downscaling of the GST thickness. Prior works on GST TFTs have typically shown poor current modulation capabilities with ON/OFF ratios ≤20 and non-saturating output characteristics. By reducing the GST thickness to 5 nm, we achieve ON/OFF ratios up to ≈300 and a channel pinch-off leading to drain current saturation. We compare the GST TFTs in their amorphous (as deposited) state and in their crystalline (annealed at 200 ∘ C) state. The highest effective field-effect mobility of 6.7 cm 2 /Vs is achieved for 10-nm-thick crystalline GST TFTs, which have an ON/OFF ratio of ≈16. The highest effective field-effect mobility in amorphous GST TFTs is 0.04 cm 2 /Vs, which is obtained in devices with a GST thickness of 5 nm. The devices remain fully operational upon bending to a radius of 6 mm. Furthermore, we find that the TFTs with amorphous channels are more sensitive to bias stress than the ones with crystallized channels. These results show that GST semiconductors are compatible with flexible electronics technology, where high-performance p-type TFTs are strongly needed for the realization of hybrid complementary metal-oxide-semiconductor (CMOS) technology in conjunction with popular n-type oxide semiconductor materials.

Metal-Halide Perovskites for Gate Dielectrics in Field-Effect Transistors and Photodetectors Enabled by PMMA Lift-Off Process.

Metal-halide perovskites have emerged as promising materials for optoelectronics applications, such as photovoltaics, light-emitting diodes, and photodetectors due to their excellent photoconversion efficiencies. However, their instability in aqueous solutions and most organic solvents has complicated their micropatterning procedures, which are needed for dense device integration, for example, in displays or cameras. In this work, a lift-off process based on poly(methyl methacrylate) and deep ultraviolet lithography on flexible plastic foils is presented. This technique comprises simultaneous patterning of the metal-halide perovskite with a top electrode, which results in microscale vertical device architectures with high spatial resolution and alignment properties. Hence, thin-film transistors (TFTs) with methyl-ammonium lead iodide (MAPbI3 ) gate dielectrics are demonstrated for the first time. The giant dielectric constant of MAPbI3 (>1000) leads to excellent low-voltage TFT switching capabilities with subthreshold swings ≈80 mV decade-1 over ≈5 orders of drain current magnitude. Furthermore, vertically stacked low-power Au-MAPbI3 -Au photodetectors with close-to-ideal linear response (R2 = 0.9997) are created. The mechanical stability down to a tensile radius of 6 mm is demonstrated for the TFTs and photodetectors, simultaneously realized on the same flexible plastic substrate. These results open the way for flexible low-power integrated (opto-)electronic systems based on metal-halide perovskites.

Pigeon homing along highways and exits.

BACKGROUND: Anecdotal observations and early airplane and helicopter tracking studies suggest that pigeons sometimes follow large roads and use landmarks as turning points during their homeward journey. However, technical limitations in tracking pigeon routes have prevented proof. RESULTS: Here, we present experimental and statistical evidence for this strategy from the analysis of 216 GPS-recorded pigeon tracks over distances up to 50 km. Experienced pigeons released from familiar sites during 3 years around Rome, Italy, were significantly attracted to highways and a railway track running toward home, in many cases without anything forcing them to follow such guide-rails. Birds often broke off from the highways when these veered away from home, but many continued their flight along the highway until a major junction, even when the detour added substantially to their journey. The degree of road following increased with repeated releases but not flight length. Significant road following (in 40%-50% of the tracks) was mainly observed from release sites along northwest-southeast axis. CONCLUSIONS: Our data demonstrate the existence of a learned road-following homing strategy of pigeons and the use of particular topographical points for final navigation to the loft. Apparently, the better-directed early stages of the flight compensated the added final detour. During early and middle stages of the flight, following large and distinct roads is likely to reflect stabilization of a compass course rather than the presence of a mental roadmap. A cognitive (roadmap) component manifested by repeated crossing of preferred topographical points, including highway exits, is more likely when pigeons approach the loft area. However, it might only be expected in pigeons raised in an area characterized by navigationally relevant highway systems.

Detecting Disordered Breathing and Limb Movement Using In-Bed Force Sensors.

We present and evaluate measurement fusion and decision fusion for recognizing apnea and periodic limb movement in sleep episodes. We used an in-bed sensor system composed of an array of strain gauges to detect pressure changes corresponding to respiration and body movement. The sensor system was placed under the bed mattress during sleep and continuously recorded pressure changes. We evaluated both fusion frameworks in a study with nine adult participants that had mixed occurrences of normal sleep, apnea, and periodic limb movement. Both frameworks yielded similar recognition accuracies of 72.1 ± âˆ¼  12% compared to 63.7 ± 17.4% for a rule-based detection reported in the literature. We concluded that the pattern recognition methods can outperform previous rule-based detection methods for classifying disordered breathing and period limb movements simultaneously.

Supporting One-Time Point Annotations for Gesture Recognition.

This paper investigates a new annotation technique that reduces significantly the amount of time to annotate training data for gesture recognition. Conventionally, the annotations comprise the start and end times, and the corresponding labels of gestures in sensor recordings. In this work, we propose a one-time point annotation in which labelers do not have to select the start and end time carefully, but just mark a one-time point within the time a gesture is happening. The technique gives more freedom and reduces significantly the burden for labelers. To make the one-time point annotations applicable, we propose a novel BoundarySearch algorithm to find automatically the correct temporal boundaries of gestures by discovering data patterns around their given one-time point annotations. The corrected annotations are then used to train gesture models. We evaluate the method on three applications from wearable gesture recognition with various gesture classes (10-17 classes) recorded with different sensor modalities. The results show that training on the corrected annotations can achieve performances close to a fully supervised training on clean annotations (lower by just up to 5 percent F1-score on average). Furthermore, the BoundarySearch algorithm is also evaluated on the ChaLearn 2014 multi-modal gesture recognition challenge recorded with Kinect sensors from computer vision and achieves similar results.

mHealth Technologies for Palliative Care Patients at the Interface of In-Patient to Outpatient Care: Protocol of Feasibility Study Aiming to Early Predict Deterioration of Patient's Health Status.

BACKGROUND: Palliative care patients are a particularly vulnerable population and one of the critical phases in patients' trajectories is discharge from specialized in-patient palliative care into outpatient care, where availability of a palliative care infrastructure is highly variable. A relevant number of potentially avoidable readmissions and emergency visits of palliative patients is observed due to rapid exacerbation of symptoms indicating the need for a closer patient monitoring. In the last years, different mHealth technology applications have been evaluated in many different patient groups. OBJECTIVE: The aim of our study is to test feasibility of a remote physical and social tracking system in palliative care patients. METHODS: A feasibility study with explorative, descriptive study design, comprised of 3 work packages. From the wards of the Clinic of Radiation-Oncology at the University Hospital Zurich, including the specialized palliative care ward, 30 patients will be recruited and will receive a mobile phone and a tracking bracelet before discharge. The aim of work package A is to evaluate if severely ill patients accept to be equipped with a tracking bracelet and a mobile phone (by semiquantitative questionnaires and guideline interviews). Work package B evaluates the technical feasibility and quality of the acquired electronic health data. Work package C will demonstrate whether physical activity parameters, such as step count, sleep duration, social activity patterns like making calls, and vital signs (eg, heart rate) do correlate with subjective health data and can serve as indicator to early detect and predict changes in patients' health status. Activity parameters will be extracted from the mobile phone's and wristband's sensor data using signal processing methods. Subjective health data is captured via electronic version of visual analog scale and Distress Thermometer as well as the European Organization for Research and Treatment of Cancer - Quality of Life Questionnaire C30 in paper version. RESULTS: Enrollment began in February 2017. First study results will be reported in the middle of 2018. CONCLUSIONS: Our project will deliver relevant data on patients' acceptance of activity and social tracking and test the correlation between subjective symptom assessment and objective activity in the vulnerable population of palliative care patients. The proposed study is meant to be preparatory work for an intervention study to test the effect of wireless monitoring of palliative care patients on symptom control and quality of life.