Thin-film microelectronic wearable body sensors.

This review of various applications of well-established thin-film processing techniques to wearable body sensors gives examples of work done in the author's laboratory over many years. Sensors for the vital signs of body temperature, electrocardiogram, heart rate, breathing pattern and breathing rate are presented along with other applications. Thin-film based sensors have the advantage of small size, high surface area to mass ratio, flexibility, capability for batch production, and compatibility with other microelectronic technologies.

Neonatal heartbeat annunciator for use in the developing world.

The majority of neonatal deaths occur in the developing countries. In many cases, unresponsive infants at birth are alive although birth attendants think they are dead and do not attempt to resuscitate them. In order to address this problem, training for birth attendant skills for resuscitation and having a device to determine the newborn heartbeat are necessary.

Energy intake estimation from counts of chews and swallows.

Current, validated methods for dietary assessment rely on self-report, which tends to be inaccurate, time-consuming, and burdensome. The objective of this work was to demonstrate the suitability of estimating energy intake using individually-calibrated models based on Counts of Chews and Swallows (CCS models). In a laboratory setting, subjects consumed three identical meals (training meals) and a fourth meal with different content (validation meal).

Powering biomedical devices with body motion.

Energy harvesting from body motion is an alternative power source that can be used to energize miniature electronic biomedical devices. This technology can make it possible to recharge batteries to reduce the frequency of or eliminate surgeries to replace depleted cells. Power availability evaluation from walking and running at several body locations and different speeds is presented.

Detection of food intake from swallowing sequences by supervised and unsupervised methods.

Studies of food intake and ingestive behavior in free-living conditions most often rely on self-reporting-based methods that can be highly inaccurate. Methods of Monitoring of Ingestive Behavior (MIB) rely on objective measures derived from chewing and swallowing sequences and thus can be used for unbiased study of food intake with free-living conditions. Our previous study demonstrated accurate detection of food intake in simple models relying on observation of both chewing and swallowing.

Body motion for powering biomedical devices.

Kinetic energy harvesting has been demonstrated as a useful technique for powering portable electronic devices. Body motion can be used to generate energy to power small electronic devices for biomedical applications. These scavengers can recharge batteries, extending their operation lifetime or even replace them.

Automatic detection of swallowing events by acoustical means for applications of monitoring of ingestive behavior.

Our understanding of etiology of obesity and overweight is incomplete due to lack of objective and accurate methods for monitoring of ingestive behavior (MIB) in the free-living population. Our research has shown that frequency of swallowing may serve as a predictor for detecting food intake, differentiating liquids and solids, and estimating ingested mass. This paper proposes and compares two methods of acoustical swallowing detection from sounds contaminated by motion artifacts, speech, and external noise.

Toward objective monitoring of ingestive behavior in free-living population.

Understanding of eating behaviors associated with obesity requires objective and accurate monitoring of food intake patterns. Accurate methods are available for measuring total energy expenditure and its components in free-living populations, but methods for measuring food intake in free-living people are far less accurate and involve self-reporting or subjective monitoring. We suggest that chews and swallows can be used for objective monitoring of ingestive behavior.

Measurement of sodium ion concentration in undiluted urine with cation-selective polymeric membrane electrodes after the removal of interfering compounds.

The measurement of sodium ion concentration in urine can provide diagnostic information and guide therapy. Unfortunately, neutral-carrier-based ion-selective electrodes show a large positive drift and loss in selectivity in undiluted urine. The extraction of electrically neutral lipids from the urine into the sensing membrane was suggested as the main source of the drift, loss of selectivity and the consequent incorrect concentration readings.

Precursors of cardiorespiratory events in infants detected by home memory monitor.

In 1,079 infants monitored for >700,000 hr at home for apnea or bradycardia, we found an association between infants having multiple events exceeding conventional or a priori defined more extreme thresholds and less favorable developmental outcome at 1 year of age than infants with few or no events. If it is necessary to prevent such events to minimize risk for developmental morbidity, there is reason to determine whether there are disturbances in advance of the apnea or bradycardia that herald their onset. In the 85 infants with at least 1 extreme event and 1 conventional event, we hypothesized that apnea and bradycardia do not occur de novo but rather are preceded by cardiorespiratory and hemoglobin O2 saturation changes.

Microfabricated sensors for biomedical applications.

Biomedical sensors couple physiological variables in living and other biologic systems to electronic instrumentation for making measurements. Microfabrication technology such as used in the microelectronics industry has been applied in the fabrication of biomedical sensors. Thin- and thick-film processing is especially well-suited to fabricating physical and chemical sensors due to the special properties of these films and the relative low costs for their production compared to other microfabrication technologies.