scholarly journals Numerical Study on the Feasibility of a 24 GHz ISM-Band Doppler Radar Antenna for Near-Field Sensing of Human Respiration in Electromagnetic Aspects

2020 ◽  
Vol 10 (18) ◽  
pp. 6159 ◽  
Author(s):  
Seungyong Park ◽  
Sungpeel Kim ◽  
Dong Kyoo Kim ◽  
Jaehoon Choi ◽  
Kyung-Young Jung

The feasibility study of a 24 GHz industrial, scientific, and medical (ISM) band Doppler radar antenna in electromagnetic aspects is numerically performed for near-field sensing of human respiration. The Doppler radar antenna consists of a transmitting (Tx) antenna and a receiving (Rx) antenna close to the human body for a wearable device. The designed slot-type Doppler radar antenna is embedded between an RO4350B superstrate and an FR-4 substrate. To obtain the higher radiation pattern of the antenna towards the human body, a ground plane reflector is placed underneath the substrate. The measured −10 dB reflection coefficient (S11) bandwidth is 23.74 to 25.56 GHz and the mutual coupling (S21) between Tx and Rx antennas is lower than −30 dB at target frequencies. The Doppler radar performance of the proposed Doppler radar antenna is performed numerically by investigating the signal returned from the human body. The Doppler effect due to human respiration is investigated through the I/Q and arctangent demodulation of the returned signal. According to the results, the phase variation of the returned signal is proportional to the displacement of the body surface, which is about 0.8 rad in accordance with 1 mm displacement. The numerical experiments indicate that the proposed Doppler radar antenna can be used for near-field sensing of human respiration in electromagnetic aspects.

2019 ◽  
Vol 18 (7) ◽  
pp. 1532-1536 ◽  
Author(s):  
Sungpeel Kim ◽  
Dong Kyoo Kim ◽  
Youjin Kim ◽  
Jaehoon Choi ◽  
Kyung-Young Jung

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1431
Author(s):  
Ilkyu Kim ◽  
Sun-Gyu Lee ◽  
Yong-Hyun Nam ◽  
Jeong-Hae Lee

The development of biomedical devices benefits patients by offering real-time healthcare. In particular, pacemakers have gained a great deal of attention because they offer opportunities for monitoring the patient’s vitals and biological statics in real time. One of the important factors in realizing real-time body-centric sensing is to establish a robust wireless communication link among the medical devices. In this paper, radio transmission and the optimal characteristics for impedance matching the medical telemetry of an implant are investigated. For radio transmission, an integral coupling formula based on 3D vector far-field patterns was firstly applied to compute the antenna coupling between two antennas placed inside and outside of the body. The formula provides the capability for computing the antenna coupling in the near-field and far-field region. In order to include the effects of human implantation, the far-field pattern was characterized taking into account a sphere enclosing an antenna made of human tissue. Furthermore, the characteristics of impedance matching inside the human body were studied by means of inherent wave impedances of electrical and magnetic dipoles. Here, we demonstrate that the implantation of a magnetic dipole is advantageous because it provides similar impedance characteristics to those of the human body.


Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1636 ◽  
Author(s):  
Nurul Huda Abd Rahman ◽  
Yoshihide Yamada ◽  
Muhammad Shakir Amin Nordin

Previous works have shown that wearable antennas can operate ideally in free space; however, degradation in performance, specifically in terms of frequency shifts and efficiency was observed when an antenna structure was in close proximity to the human body. These issues have been highlighted many times yet, systematic and numerical analysis on how the dielectric characteristics may affect the technical behavior of the antenna has not been discussed in detail. In this paper, a wearable antenna, developed from a new electro-textile material has been designed, and the step-by-step manufacturing process is presented. Through analysis of the frequency detuning effect, the on-body behavior of the antenna is evaluated by focusing on quantifying the changes of its input impedance and near-field distribution caused by the presence of lossy dielectric material. When the antenna is attached to the top of the body fat phantom, there is an increase of 17% in impedance, followed by 19% for the muscle phantom and 20% for the blood phantom. These phenomena correlate with the electric field intensities (V/m) observed closely at the antenna through various layers of mediums (z-axis) and along antenna edges (y-axis), which have shown significant increments of 29.7% in fat, 35.3% in muscle and 36.1% in blood as compared to free space. This scenario has consequently shown that a significant amount of energy is absorbed in the phantoms instead of radiated to the air which has caused a substantial drop in efficiency and gain. Performance verification is also demonstrated by using a fabricated human muscle phantom, with a dielectric constant of 48, loss tangent of 0.29 and conductivity of 1.22 S/m.


2011 ◽  
Vol 301-303 ◽  
pp. 1214-1219
Author(s):  
Hong Dun Lin ◽  
Yen Shien Lee ◽  
Yu Jen Su ◽  
Bor Nian Chuang

Clinically, basic physiological signal measurement, such as cardiovascular vibration and respiration motion detection, reveals important vital information of clinical diagnosis or personal health status evaluation. In routine, there are many preferable non-invasive methods, including electrocardiogram (ECG), pressure-sensitive transducers and applanation tonometry, to get insight of the sign of life. However, the operation of traditional monitors is relied on professionals’ experience, and also the sensing probes needed to contact to the user’s skin directly. The measurement procedure is easy to cause inconvenient and uncomfortable. To improve the issues of these measuring techniques, the non-contact and non-invasive measuring method will become an important innovation. In this paper, the novel nanosecond pulse near-field sensing (NPNS) based screening technology, which includes radio frequency (RF) pulse transmission and a flat antenna connected to transceiver of miniature radar, is proposed to monitor physical activity inside body. A dedicate analysis software built in Smartphone is also provided to calculate desired parameters, including heart rate and breath rate, for clinical or common personal applications. To evaluate the performance, the proposed method was applied on motion measurement at the body site of chest. As a result, the proposed method is validated to perform the capability of continuously long-term monitoring to reveal cardiovascular information in real-time.


2003 ◽  
Vol 1 ◽  
pp. 329-333
Author(s):  
K. Ruf ◽  
E. Fürst ◽  
K. Grypstra ◽  
J. Neidhöfer ◽  
M. Schumacher

Abstract. Short range radar (SRR) for cars has been proposed to operate over 5 GHz of bandwidth at the 24 GHz ISM band. To estimate the level of interference from these devices on radio telescopes, the near-field antenna pattern has to be known. We report on new measurements with the Effelsberg 100 m radio telescope. These measurements were performed with a transmitter set up at a distance of 1.7 km from the telescope. The strength of the signal picked up by the telescope sidelobes shows that the proposed SRR would interfere with sensitive radio astronomical observations.


Author(s):  
Sungpeel Kim ◽  
Jihoon Bang ◽  
Kyoseung Keum ◽  
Jaehoon Choi ◽  
Kyung-Young Jung ◽  
...  

2020 ◽  
Vol 10 (21) ◽  
pp. 7392
Author(s):  
Massinissa Ziane ◽  
Ronan Sauleau ◽  
Maxim Zhadobov

Wireless devices, such as smartphones, tablets, and laptops, are intended to be used in the vicinity of the human body. When an antenna is placed close to a lossy medium, near-field interactions may modify the electromagnetic field distribution. Here, we analyze analytically and numerically the impact of antenna/human body interactions on the transmitted power density (TPD) at 60 GHz using a skin-equivalent model. To this end, several scenarios of increasing complexity are considered: plane-wave illumination, equivalent source, and patch antenna arrays. Our results demonstrate that, for all considered scenarios, the presence of the body in the vicinity of a source results in an increase in the average TPD. The local TPD enhancement due to the body presence close to a patch antenna array reaches 95.5% for an adult (dry skin). The variations are higher for wet skin (up to 98.25%) and for children (up to 103.3%). Both absolute value and spatial distribution of TPD are altered by the antenna/body coupling. These results suggest that the exact distribution of TPD cannot be retrieved from measurements of the incident power density in free-space in absence of the body. Therefore, for accurate measurements of the absorbed and epithelial power density (metrics used as the main dosimetric quantities at frequencies > 6 GHz), it is important to perform measurements under conditions where the wireless device under test is perturbed in the same way as by the presence of the human body in realistic use case scenarios.


2019 ◽  
pp. 3-13
Author(s):  
Alexandru Cîtea ◽  
George-Sebastian Iacob

Posture is commonly perceived as the relationship between the segments of the human body upright. Certain parts of the body such as the cephalic extremity, neck, torso, upper and lower limbs are involved in the final posture of the body. Musculoskeletal instabilities and reduced postural control lead to the installation of nonstructural posture deviations in all 3 anatomical planes. When we talk about the sagittal plane, it was concluded that there are 4 main types of posture deviation: hyperlordotic posture, kyphotic posture, rectitude and "sway-back" posture.Pilates method has become in the last decade a much more popular formof exercise used in rehabilitation. The Pilates method is frequently prescribed to people with low back pain due to their orientation on the stabilizing muscles of the pelvis. Pilates exercise is thus theorized to help reactivate the muscles and, by doingso, increases lumbar support, reduces pain, and improves body alignment.


Humaniora ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 83-90
Author(s):  
Anak Agung Ayu Wulandari ◽  
Ade Ariyani Sari Fajarwati

The research would look further at the representation of the human body in both Balinese and Javanese traditional houses and compared the function and meaning of each part. To achieve the research aim, which was to evaluate and compare the representation of the human body in Javanese and Balinese traditional houses, a qualitative method through literature and descriptive analysis study was conducted. A comparative study approach would be used with an in-depth comparative study. It would revealed not only the similarities but also the differences between both subjects. The research shows that both traditional houses represent the human body in their way. From the architectural drawing top to bottom, both houses show the same structure that is identical to the human body; head at the top, followed by the body, and feet at the bottom. However, the comparative study shows that each area represents a different meaning. The circulation of the house is also different, while the Balinese house is started with feet and continued to body and head area. Simultaneously, the Javanese house is started with the head, then continued to body, and feet area.


Sign in / Sign up

Export Citation Format

Share Document