Piezofilm yarn sensor-integrated knitted fabric for healthcare applications

Knitted fabric sensors have been widely used as strain sensors in the sports health field and its large strain performance and structure are suitable for human body movements. When a knitted structure is worn, different human body movements are reflected through the large strain deformation of fabric structure and consequently change the electrical signal. Here, the mechanical and electrical properties of highly elastic knitted sweatpants were tested under large strain. This sensor has good sensitivity and stability during movement. Compared with traditional motion monitoring, this technique divides the walking cycle into two stages, namely, stance and swing phases, which can be further subdivided into six stages. The corresponding resistance characteristic values can accurately distinguish the gait cycle. Analysis on hysteresis and repeatability revealed that the sensor exhibits a constant electrical performance. Four kinds of motion postures were predicted and judged by comparing the resistance characteristic range value, peak value calculation function and time axis. The measured sensor outputs were transferred to a computer via 4.0 Bluetooth. Matlab language was used to detect the status through a rule-based algorithm and the sensor outputs.

Section: Introductionmentioning

confidence: 99%

Human Motion Recognition of Knitted Flexible Sensor in Walking Cycle

Miao

Niu

et al. 2019

“…Some materials have been investigated for the fabrication of wearable flexible sensors, such as conductive rubber [ 13 , 14 ], conductive fibers/fabrics [ 15 , 16 , 17 , 18 , 19 ], polyvinylidene fluoride (PVDF) [ 20 , 21 ], and nanocomposites [ 22 , 23 ]. Conductive rubber is easy to manufacture and can conduct multi-point measurements, but is mostly used for pressure testing and can exhibit relaxation phenomena that decrease precision.…”

Section: Introductionmentioning

confidence: 99%

“…Conductive fibers and fabrics have high sensitivity, but require a complex manufacturing process, and the conductivity of polypyrrole decreases rapidly with time [ 17 ]. PVDF film has flexibility, and has excellent sensitivity and dynamic response; however, it exhibits charge leakage phenomena [ 21 ]. Regarding nanocomposites, metal-coated CNT-epoxy nanocomposites show high sensitivity in the detection of human respiration and pulse, but it is not suitable to monitor large displacements such as of wrist motion because of the very low stretchability [ 22 ].…”

Section: Introductionmentioning

confidence: 99%

Wearable Stretch Sensors for Motion Measurement of the Wrist Joint Based on Dielectric Elastomers

Huang

Mei

et al. 2017

Motion capture of the human body potentially holds great significance for exoskeleton robots, human-computer interaction, sports analysis, rehabilitation research, and many other areas. Dielectric elastomer sensors (DESs) are excellent candidates for wearable human motion capture systems because of their intrinsic characteristics of softness, light weight, and compliance. In this paper, DESs were applied to measure all component motions of the wrist joints. Five sensors were mounted to different positions on the wrist, and each one is for one component motion. To find the best position to mount the sensors, the distribution of the muscles is analyzed. Even so, the component motions and the deformation of the sensors are coupled; therefore, a decoupling method was developed. By the decoupling algorithm, all component motions can be measured with a precision of 5°, which meets the requirements of general motion capture systems.

“…To improve its effectiveness, some researches combined the oral appliance with pressure sensors to detect tongue position [ 6 , 7 , 8 ] but didn’t make it a total solution. There are some other works about wearable health monitoring systems using soft sensing technologies to detect respiratory activities [ 9 , 10 , 11 ]. These systems with flexible sensors achieve real-time monitoring with promising results but need to incorporate with bulky equipment for subsequent signal processing.…”

Section: Introductionmentioning

confidence: 99%

A Wireless Monitoring System Using a Tunneling Sensor Array in a Smart Oral Appliance for Sleep Apnea Treatment

Yeh

et al. 2017

Sleep apnea is a serious sleep disorder, and the most common type is obstructive sleep apnea (OSA). Untreated OSA will cause lots of potential health problems. Oral appliance therapy is an effective and popular approach for OSA treatment, but making a perfect fit for each patient is time-consuming and decreases its efficiency considerably. This paper proposes a System-on-a-Chip (SoC) enabled sleep monitoring system in a smart oral appliance, which is capable of intelligently collecting the physiological data about tongue movement through the whole therapy. A tunneling sensor array with an ultra-high sensitivity is incorporated to accurately detect the subtle pressure from the tongue. When the device is placed on the wireless platform, the temporary stored data will be retrieved and wirelessly transmitted to personal computers and cloud storages. The battery will be recharged by harvesting external RF power from the platform. A compact prototype module, whose size is 4.5 × 2.5 × 0.9 cm3, is implemented and embedded inside the oral appliance to demonstrate the tongue movement detection in continuous time frames. The functions of this design are verified by the presented measurement results. This design aims to increase efficiency and make it a total solution for OSA treatment.