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BACKGROUND The available methods for monitoring food intake—which for a great part rely on self-report—often provide biased and incomplete data. Currently, no good technological solutions are available. Hence, the SPLENDID eating detection sensor (an ear-worn device with an air microphone and a photoplethysmogram [PPG] sensor) was developed to enable complete and objective measurements of eating events. The technical performance of this device has been described before. To date, literature is lacking a description of how such a device is perceived and experienced by potential users. OBJECTIVE The objective of our study was to explore how potential users perceive and experience the SPLENDID eating detection sensor. METHODS Potential users evaluated the eating detection sensor at different stages of its development: (1) At the start, 12 health professionals (eg, dieticians, personal trainers) were interviewed and a focus group was held with 5 potential end users to find out their thoughts on the concept of the eating detection sensor. (2) Then, preliminary prototypes of the eating detection sensor were tested in a laboratory setting where 23 young adults reported their experiences. (3) Next, the first wearable version of the eating detection sensor was tested in a semicontrolled study where 22 young, overweight adults used the sensor on 2 separate days (from lunch till dinner) and reported their experiences. (4) The final version of the sensor was tested in a 4-week feasibility study by 20 young, overweight adults who reported their experiences. RESULTS Throughout all the development stages, most individuals were enthusiastic about the eating detection sensor. However, it was stressed multiple times that it was critical that the device be discreet and comfortable to wear for a longer period. In the final study, the eating detection sensor received an average grade of 3.7 for wearer comfort on a scale of 1 to 10. Moreover, experienced discomfort was the main reason for wearing the eating detection sensor CONCLUSIONS The SPLENDID eating detection sensor, which uses an air microphone and a PPG sensor, is a promising new device that can facilitate the collection of reliable food intake data, as shown by its technical potential. Potential users are enthusiastic, but to be successful wearer comfort and discreetness of the device need to be improved.

BackgroundThe available methods for monitoring food intake—which for a great part rely on self-report—often provide biased and incomplete data. Currently, no good technological solutions are available. Hence, the SPLENDID eating detection sensor (an ear-worn device with an air microphone and a photoplethysmogram [PPG] sensor) was developed to enable complete and objective measurements of eating events. The technical performance of this device has been described before. To date, literature is lacking a description of how such a device is perceived and experienced by potential users. ObjectiveThe objective of our study was to explore how potential users perceive and experience the SPLENDID eating detection sensor. MethodsPotential users evaluated the eating detection sensor at different stages of its development: (1) At the start, 12 health professionals (eg, dieticians, personal trainers) were interviewed and a focus group was held with 5 potential end users to find out their thoughts on the concept of the eating detection sensor. (2) Then, preliminary prototypes of the eating detection sensor were tested in a laboratory setting where 23 young adults reported their experiences. (3) Next, the first wearable version of the eating detection sensor was tested in a semicontrolled study where 22 young, overweight adults used the sensor on 2 separate days (from lunch till dinner) and reported their experiences. (4) The final version of the sensor was tested in a 4-week feasibility study by 20 young, overweight adults who reported their experiences. ResultsThroughout all the development stages, most individuals were enthusiastic about the eating detection sensor. However, it was stressed multiple times that it was critical that the device be discreet and comfortable to wear for a longer period. In the final study, the eating detection sensor received an average grade of 3.7 for wearer comfort on a scale of 1 to 10. Moreover, experienced discomfort was the main reason for wearing the eating detection sensor

In the context of dietary management, accurate monitoring of eating habits is receiving increased attention. Wearable sensors, combined with the connectivity and processing of modern smartphones, can be used to robustly extract objective and real-time measurements of human behavior. In particular, for the task of chewing detection, several approaches based on an in-ear microphone can be found in the literature, while other types of sensors have also been reported, such as strain sensors. In this paper, performed in the context of the SPLENDID project, we propose to combine an in-ear microphone with a photoplethysmography (PPG) sensor placed in the ear concha, in a new high accuracy and low sampling rate prototype chewing detection system. We propose a pipeline that initially processes each sensor signal separately, and then fuses both to perform the final detection. Features are extracted from each modality, and support vector machine (SVM) classifiers are used separately to perform snacking detection. Finally, we combine the SVM scores from both signals in a late-fusion scheme, which leads to increased eating detection accuracy. We evaluate the proposed eating monitoring system on a challenging, semifree living dataset of 14 subjects, which includes more than 60 h of audio and PPG signal recordings. Results show that fusing the audio and PPG signals significantly improves the effectiveness of eating event detection, achieving accuracy up to 0.938 and class-weighted accuracy up to 0.892.

Monitoring of human eating behaviour has been attracting interest over the last few years, as a means to a healthy lifestyle, but also due to its association with serious health conditions, such as eating disorders and obesity. Use of self-reports and other non-automated means of monitoring have been found to be unreliable, compared to the use of wearable sensors. Various modalities have been reported, such as acoustic signal from ear-worn microphones, or signal from wearable strain sensors. In this work, we introduce a new sensor for the task of chewing detection, based on a novel photoplethysmography (PPG) sensor placed on the outer earlobe to perform the task. We also present a processing pipeline that includes two chewing detection algorithms from literature and one new algorithm, to process the captured PPG signal, and present their effectiveness. Experiments are performed on an annotated dataset recorded from 21 individuals, including more than 10 hours of eating and non-eating activities. Results show that the PPG sensor can be successfully used to support dietary monitoring.

INTRODUCTION: Electrocardiographic criteria for left ventricular hypertrophy (LVH) have been limited by low sensitivity at acceptable levels of specificity. A number of studies have demonstrated that body mass index (BMI) is associated with decreased sensitivity of ECG LVH classification in hypertensive patients. The objective of this study is to investigate the correlation relationship between LVH voltage criteria and BMI in Swiss conscripts. METHODS: A database of 41,806 young Swiss people, who underwent compulsory conscription for the Swiss Army, was compiled. Along with other medical data, an ECG was taken. Statistical analyses, such as linear regression and calculation of correlation coefficient, were carried out between LVH voltage criteria and BMI. RESULTS: The mean age in the studied population was 19.2 +/- 1.1 years with a median age of 19 years (range from 17 to 38 years). We found an overweight prevalence of 25.1%. The results showed that body habitus had significant association with Sokolow-Lyon voltages. A mean decrease of 13%, 5%, 19%, 14%, and 12% for the five studied Sokolow-Lyon indexes were found between normal range subjects (18.5 > or = BMI > 25) and obese subjects (25> or = BMI). CONCLUSIONS: Our study confirms the hypothesis that people with higher BMI, a growing section of the population, have lower ECG amplitudes. Therefore, the Sokolow-Lyon voltage criteria may underestimate the presence of LVH for subjects with higher BMI, which is not the case for the Cornell voltage. Our analysis suggests that computerized electrocardiography for the diagnosis of left ventricular hypertrophy based on Sokolow-Lyon voltages should incorporate the BMI factor.

The face diagonal method for squareness error measurement is already well established. Because it is easy to apply, this method is widely used in CMMs (coordinate measuring machines). This paper introduces a new method, which reduces the set-up and measuring time for squareness error by applying four volumetric diagonal measurements instead of six face diagonal measurements. The method also makes it possible to use a single properly sized artefact, which fits the machine’s rectangular volume. The choice of artefacts used in the method is wide, and they need not be precalibrated before measurements.

This paper describes a novel fully integrated circuit implemented in standard 0.35 ?m CMOS technology dedicated to biological signal measurement such as ECG or EEG signals. Based on a new CMOS current conveyor (a low power 60 ?A @ ±1.5 V power supply, 88 × 100 ?m2 area, 100 MHz bandwidth and 10 GHz equivalent GBW circuit) the instrumentation amplifier used in this IC has a weaker offset and a better CMRR than its equivalent in Voltage mode. In order to totally cancel output offset Voltage and reduce noise, the input signal and output signal of the instrumentation amplifier are chopped at high frequency. The size and the architecture of this IC make biological signal measurement in very hostile environment such MRI, possible.

In this paper a new 0.35 μm CMOS technology second generation current conveyor (CCII) is presented. It is a low power (60 μA @ ± 1.5 V power supply) circuit, featuring 88 × 100 μm2 area, 100 MHz bandwidth and 10 GHz equivalent gain bandwidth (GBW) product. Its static and dynamic characteristics when used both as a voltage and current buffer are described. The chip has been fabricated and tested, and experimental results are discussed. Its use in an application as an instrumentation amplifier (IA) is also presented. The CCII based IA has weaker offset and better CMRR than its voltage mode equivalent. In order to cancel output offset voltage and reduce noise, the IA's input and output signals are chopped at high frequency.

This paper describes two novel fully integrated circuits implemented in standard 0.35 μm CMOS technology dedicated to ECG signal measurement. Many specific problems related to this kind of signal are discussed. Pertinent solutions, such as high pass filtering, offset cancellation, common mode rejection, low pass filtering and capacitive coupling between different stages are proposed.

The integration of an electrocardiogram (ECG) device into a chip is already well known in the field of implanted devices, such as pacemakers. For noninvasive electrocardiology, this approach has not been used on a broad scale commercially. The extension of electrocardiology to telemetry, home care, and special applications as in magnetic resonance imaging has spawned a new interest in highly miniaturized ECG devices. In our company, we are aiming for using highly integrated devices exactly in these fields. On one hand, the home monitoring market (“eHealth,” “pHealth”) requires small and lightweight devices (“ECG in an electrode”); on the other hand, the use of an ECG device within a hostile environment as in an magnetic resonance imaging machine with strong electromagnetic fields requires small dimensions of the device. Of these 2 fields, the one of home monitoring is the most promising. There is a large population in need of such monitoring (eg, patients with congestive heart failure), and the cost issue in medical care drives the market in this direction. Projects in both fields will be presented as well as the first experiences as a middle-sized manufacturer in trying to produce an integrated ECG “device.”

In this paper we present an integrated ECG acquisition system implemented in a standard 0.35 μm CMOS technology. The system mainly consists of amplifiers, filters and an automatic offset compensation module. Composed of comparator, control logic and D/A converter, the compensator is an analog-digital mixed system and designed through a top-down approach. It is an independent module and can be easily reused. A low-pass filter of low cutoff frequency has been realized by using a Gm-C structure with very low bias current. Experimental measurements on the fabricated chip have been done. The results show that the integrated circuit works well with a low noise, a low consumption and a high efficacy of the offset compensator.

Negative correlation relationship between left ventricular hypertrophy Sokolow-Lyon and body mass in 41 806 Swiss conscripts Roger Abacherli, Richard Kobza, Bernhard Niggli, Lingchuan Zhou, Johann-Jakob Schmid, Franz Frey, Paul Erne, ( SCHILLER AG, Biomed. Research and Signalprocessing, Baar, Switzerland; Division of Cardiology, Cantonal Hospital Luzern, Switzerland; Medical Service, Swiss Army, Ittigen, Switzerland)