A portable and wireless activity monitoring system was developed for the estimation of temporal gait parameters. The new system was built using three-axis accelerometers to automatically detect walking steps with various walking speeds. The accuracy of walking step-peak detection algorithm was assessed by using a running machine with variable speeds. To assess the consistency of gait parameter analysis system, estimated parameters, such as heel-contact and toe-off time based on accelerometers and footswitches were compared for consecutive 20 steps from 19 individual healthy subjects. Accelerometers and footswitches had high consistency in the temporal gait parameters. The stance, swing, single-limb support, and double-limb support time of gait cycle revealed ICCs values of 0.95, 0.93, 0.86, and 0.75 on the right and 0.96, 0.86, 0.93, 0.84 on the left, respectively. And the walking step-peak detection accuracy was 99.15% (±0.007) for the proposed method compared to 87.48% (±0.033) for a pedometer. Therefore, the proposed activity monitoring system proved to be a reliable and useful tool for identification of temporal gait parameters and walking pattern classification.

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We measured the electrical activity signals of the heart through vital signs monitoring garments that have textile electrodes in conductive yarns while the subject is in stable and dynamic motion conditions. To measure the electrical activity signals of the heart during daily activities, four types of monitoring garment were proposed. Two experiments were carried out as follows: the first experiment sought to discover which garment led to the least displacement of the textile electrode from its originally intended location on the wearer's body. In the second, we measured and compared the electrical activity signals of the heart between the wearer's stable and dynamic motion states. The results indicated that the most appropriate type of garment sensing-wise was the "cross-type", and it seems to stabilize the electrode's position more effectively. The value of SNR of ECG signals for the "cross-type" garment is the highest. Compared to the "chest-belt-type" garment, which has already been marketed commercially, the "cross-type" garment was more efficient and suitable for heart activity monitoring.

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In this article, we propose a new algorithm using the characteristics of reconstructed phase portraits by delay-coordinate mapping utilizing lag rotundity for a real-time detection of QRS complexes in ECG signals. In reconstructing phase portrait the mapping parameters, time delay, and mapping dimension play important roles in shaping of portraits drawn in a new dimensional space. Experimentally, the optimal mapping time delay for detection of QRS complexes turned out to be 20 ms. To explore the meaning of this time delay and the proper mapping dimension, we applied a fill factor, mutual information, and autocorrelation function algorithm that were generally used to analyze the chaotic characteristics of sampled signals. From these results, we could find the fact that the performance of our proposed algorithms relied mainly on the geometrical property such as an area of the reconstructed phase portrait. For the real application, we applied our algorithm for designing a small cardiac event recorder. This system was to record patients' ECG and R-R intervals for 1 h to investigate HRV characteristics of the patients who had vasovagal syncope symptom and for the evaluation, we implemented our algorithm in C language and applied to MIT/BIH arrhythmia database of 48 subjects. Our proposed algorithm achieved a 99.58% detection rate of QRS complexes.

Objectives: Latino children are more likely to be unrestrained passengers in motor vehicles than nonLatino children, but little is known about the use of booster seats in Latino families. This study investigates Latino parents' knowledge, attitudes and beliefs about booster seats, barriers to booster seat use, and effective strategies for message delivery in the Latino community. Methods: Two focus groups were conducted with Spanish speaking parents. Information was obtained through a written survey and moderated discussions. Results: Parents were widely misinformed about recommended guidelines for booster seat use, and the majority of participants did not own a booster seat. Parents identified a lack of information, the cost of booster seats, resistance to use by the child or the father, limited space in the vehicle, and unavailability of shoulder belts as barriers to booster seat use. Participants felt that learning more about the new Washington state booster seat law and its consequences would increase booster seat use. Public health messages felt to be effective were those in Spanish, delivered by credible spokespeople such as physicians and teachers, and utilizing the Spanish media. Conclusions: Campaigns to promote booster seats in the Latino community should be culturally specific, and clear guidelines for booster seat use should be given in Spanish. Legislation may be an important incentive for using booster seats, though reducing their cost and providing strategies to address child resistance and physical constraints of some vehicles are also important. M otor vehicle collisions remain the leading cause of death in children between 4-8 years of age.1 The additional risks of injury inflicted on young children by premature use of seatbelts are well documented, and include head, spine, and abdominal injuries, the so-called "seatbelt syndrome".2 3 Seatbelt positioning booster seats have been shown to reduce serious injury in children aged 4-8. 3 It is recommended that booster seats be used until children reach 8 years, 80 pounds (36 kg), and 4 feet 9 inches (1.45 m) tall.4 5 In 2000, Washington became the first of 13 states to pass booster seat legislation. 6 However, most parents are still not using booster seats for their children; national estimates suggest that only 19% of age appropriate children are currently riding in booster seats. 7Latinos comprise the largest minority group in Washington State, making up 7.5% of the general population, and 11.8% of children aged 0-18. 8 A recent study found that Latino children in Washington were one third less likely to use a booster seat than non-Latino children.9 Previous work has shown that language differences and cultural barriers may have hindered the adoption of seatbelts and child safety restraints by Latino families.10 11 However, it has also been shown that culturally appropriate outreach programs tailored to the Latino community have been successful in increasing the use of child restraints.12 A literature search found no published data describing the ...

A method for manufacturing terahertz absorber is presented. Varying fractions of graphite powder are mixed with the host poly methylmethacrylate powder and compress molded. The shielding efficiency, together with real and imaginary parts of the dielectric constant, is unambiguously determined by terahertz time domain spectroscopy in the continuous frequency range of 0.1–1.6THz. While the composites are absorptive in most of the frequency range with relatively small reflection, it turns metallic at a high enough graphite fraction of 35.7%: there exists a zero crossing of the real part of dielectric function εr(ω) to negative values below 0.22THz. Our method provides an easy-to-control way of manufacturing terahertz absorbers with a wide range of shielding efficiency and low reflectance.

In the lubrication oil of the machinery devices, metal wearing particles reflect the wearing state in real time. Therefore, lubrication oil wearing particles monitoring system can identify the health state of the machinery devices. Based on the three-coil inductive sensor, this paper proposes the monitoring system including the exciting circuit, the detection circuit, the MCU system circuit and the host PC software. Experimental result shows that the proposed monitoring system can captures the output signal of the metal wearing particle.