MW-PPG Sensor: An on-Chip Spectrometer Approach

Chang, Cheng-Chun; Wu, Chien-Ta; Choi, Byung Il; Fang, Tong-Jing

doi:10.3390/s19173698

Cited by 20 publications

(16 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…where k is the thermal conductivity of an object, and h is the distance between the hot and cold points. While heat flux could be estimated according to (2), this would require knowing the values for k and h. Moreover, the thermal mass associated with the object will restrict the rate of change for T hot and T cold during transients in the heat flux. Instead, heat flux can be measured, e.g., using a thermoelectric heat flux sensor, which generates voltage proportional to the heat flow through the sensor structure [18].…”

Section: A Heat Flux Measurementmentioning

confidence: 99%

“…Typically, these devices contain one or more sensors for measuring signals such as heart rate, skin temperature, humidity, and movement [1]. Optical heart rate (HR) tracking, or photoplethysmography (PPG), is one of the most common biometric measurements, found in up to 98% of modern smart watches [2]. PPG, among other biometric measurements, gives the wearer the ability to track the level of their physical activity, which may be beneficial for applications such as sports performance monitoring.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Improving Energy Expenditure Estimation in Wrist-Worn Wearables by Augmenting Heart Rate Data With Heat Flux Measurement

Levikari

Immonen

Kuisma

et al. 2021

IEEE Trans. Instrum. Meas.

View full text Add to dashboard Cite

Wearable electronics are often used for estimating the energy expenditure of the user based on heart rate measurement. While heart rate is a good predictor of calorie consumption at high intensities, it is less precise at low intensity levels, which translates into inaccurate results when estimating daily net energy expenditure. In this study, heart rate measurement was augmented with heat flux measurement, a form of direct calorimetry. A physical exercise test on a group of 15 people showed that heat flux measurement can improve the accuracy of calorie consumption estimates especially during rest and lowintensity activity when used in conjunction with heart rate information and vital background parameters of the user.

show abstract

Section: A Heat Flux Measurementmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Improving Energy Expenditure Estimation in Wrist-Worn Wearables by Augmenting Heart Rate Data With Heat Flux Measurement

Levikari

Immonen

Kuisma

et al. 2021

IEEE Trans. Instrum. Meas.

View full text Add to dashboard Cite

show abstract

“…We designed a mobile app to communicate with the proposed AW-PPG device via Bluetooth Low Energy (BLE) and acquire the PPG signals in real time. As illustrated in Figure 4 , we used a mobile device to assess the physiological information, such as heart rates, SpO2, and blood pressure, using algorithms developed in our previous work [ 20 ].…”

Section: Aw-ppg Devicementioning

confidence: 99%

Development of a Portable All-Wavelength PPG Sensing Device for Robust Adaptive-Depth Measurement: A Spectrometer Approach with a Hydrostatic Measurement Example

Chen

Chuang

Chang

2020

Sensors

Self Cite

View full text Add to dashboard Cite

Photoplethysmography (PPG), a noninvasive optical sensing technology, has been widely used to measure various physiological indices. Over-the-counter PPG devices are typically composed of a single-wavelength light source, namely, single-wavelength PPG (SW-PPG). It is known that signals of SW-PPG are easily contaminated or distorted by measurement conditions such as motion artifacts, wearing pressure, and skin type. Since lights of different wavelengths can penetrate skin tissues at different depths, how to effectively construct a multiwavelength PPG (MW-PPG) device or even an all-wavelength PPG (AW-PPG) device has attracted great attention. There is also a very interesting question, that is, what could be the potential benefits of using MW-PPG or AW-PPG devices? This paper demonstrates the construction of an AW-PPG portable device and conducts a preliminary evaluation. The presented device consists of four light-emitting diodes, a chip-scale spectrometer, a microcontroller, a Bluetooth Low Energy transceiver, and a phone app. The maximum ratio combining algorithm (MRC) is used to combine the PPG signals derived from different wavelengths to achieve a better signal-to-noise ratio (S/N). The PPG signals from the developed MRC-AW-PPG device versus those from the conventional SW-PPG device are compared in terms of different hydrostatic pressure conditions. It has been observed that the MRC-AW-PPG device can provide more stable PPG signals than that of a conventional PPG device. The results shine a light on the potential benefits of using multiple wavelengths for the next generation of noninvasive PPG sensing.

show abstract

“…The measuring photodiode measures the intensity of the non-absorbed light reflected by the tissue. Recently, as an alternative technique for monitoring heart rate, the adaptation of PPG technology has increased [37]- [41]. Specifically, in wearable devices, the PPG sensor is quickly adopted due to the cost-effectiveness and simplicity of its operation.…”

Section: A Ppg Sensor Modulementioning

confidence: 99%

Wearable Computing for Defence Automation: Opportunities and Challenges in 5G Network

Sharma

Park

et al. 2020

IEEE Access

View full text Add to dashboard Cite

Recently, wearable technologies have evolved in the most unexpected field like a military force outside of healthcare, fitness, lifestyle and similar areas. The growing need for soldiers' coordination, training and health, the increase in asymmetric warfare, suspected geopolitical conflicts and soldiers' modernization programs, among others, are some of the factors that fuel the growth of the military wearables market. Wearable computation plays an important role in improving the capabilities of the soldier. Further, the 5G network promises a solution to the many network and performance challenges in order to adopt more sophisticated wearable technologies in defense automation. In this paper, we conduct a study to identify the role of wearable computing for the defence automation system. We present the taxonomy of wearable computing in defence automation system and explain the relationship of each attribute. In addition, we identify the raise issues and challenges in communication and cybersecurity when deploying the 5G network in defense automation. Furthermore, we propose the design of the wearable smartwatch architecture as a use case of healthcare transformation in defense automation in the 5G environment. INDEX TERMS Wearable computing, 5G network, security and privacy, edge computing.

show abstract

MW-PPG Sensor: An on-Chip Spectrometer Approach

Cited by 20 publications

References 26 publications

Improving Energy Expenditure Estimation in Wrist-Worn Wearables by Augmenting Heart Rate Data With Heat Flux Measurement

Improving Energy Expenditure Estimation in Wrist-Worn Wearables by Augmenting Heart Rate Data With Heat Flux Measurement

Development of a Portable All-Wavelength PPG Sensing Device for Robust Adaptive-Depth Measurement: A Spectrometer Approach with a Hydrostatic Measurement Example

Wearable Computing for Defence Automation: Opportunities and Challenges in 5G Network

Contact Info

Product

Resources

About