scholarly journals Study of RF Signal Attenuation of Human Heart

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Kedar Nath Sahu ◽  
Challa Dhanunjaya Naidu ◽  
M. Satyam ◽  
K. Jaya Sankar
Keyword(s):  
Reflection Coefficient ◽  
Human Body ◽  
Human Heart ◽  
Pulse Propagation ◽  
Cardiac Activity ◽  
Diagnostic System ◽  
Signal Attenuation ◽  
Propagation Modeling ◽  
Fixed Dimension ◽  
Rf Signal

A study of ultrawideband pulse propagation modeling through human body for all frequencies from 0.1 to 10.5 GHz is presented. Reflection coefficient and signal attenuation are computed from the model considering the variation of heart dimension with respect to time unlike a fixed dimension of heart used in earlier models. The performance of cardiac activity is studied from the change of signal attenuation. This estimation may help in the design of a noninvasive diagnostic system using ultrawideband of frequencies.

IN-SITU CHARACTERIZATIONS OF 1–200 MHz RADIO FREQUENCY SIGNAL COUPLING WITH HUMAN BODY

2012 ◽  
Vol 24 (03) ◽  
pp. 285-294 ◽  
Author(s):  
Zedong Nie ◽  
Tengfei Leng ◽  
Wenchen Wang ◽  
Feng Guan ◽  
Bangyu Huang ◽  
...  
Keyword(s):  
Human Body ◽  
Great Promise ◽  
Area Network ◽  
Coupling Loss ◽  
Signal Attenuation ◽  
In Situ Experiments ◽  
Rf Signals ◽  
The Difference ◽  
Rf Signal

Wireless communication within body proximal has shown great promise for the construction of body sensor network (BSN) and body area network (BAN), wherein multiple master and slave nodes were typically deployed on different human body sites for physiological measurements or personal entertainment. We reported the in-situ experiments to characterize body-proximal electric coupling over various carrier frequencies (1–200 MHz), multiple subjects and different body postures. To improve the signal fidelity and minimize the ground return path, all experiments were performed in a shielded radiofrequency (RF) chamber with single electrode configuration and battery-operated transmitter/receiver — the setup has never been reported in other literatures. Results obtained from 15 subjects quantified the attenuation patterns of the RF signal coupling with human body. The average coupling loss was approximately 24 dB at 30 MHz whist the receiver electrode was attached at a distance of 10 cm from the transmitter electrode, and the on-body coupling loss followed a two-piecewise fitting over distance. In comparison, 30 MHz RF signals propagated 1 m from body to air and from air to air were attenuated 70 dB and 80 dB, respectively. The standard deviations representing different subjects and daily variations were less than 2 dB at 30 MHz when the coupling distance was 10 cm. The difference in signal attenuation was always less than 2 dB for various postures including standing, sitting and squatting. It concluded that the RF signal within the frequency range of 25–30 MHz is capable of providing a robust and subject-independent wireless link for body-proximal BSN/BAN applications.

scholarly journals Conceptualizations of the Heart in Jordanian Arabic: A Cognitive Perspective

2020 ◽  
Vol 12 (4) ◽  
pp. 65
Author(s):  
Omar Bani Mofarrej ◽  
Ghaleb Rabab'ah
Keyword(s):  
Human Body ◽  
Human Heart ◽  
Conceptual Metaphor ◽  
Cognitive Mechanisms ◽  
Conceptual Metaphor Theory ◽  
Cognitive Perspective ◽  
Jordanian Arabic ◽  
Metaphor Theory ◽  
Idiomatic Expressions ◽  
Levantine Arabic

The present paper examines the metaphorical and metonymical conceptualizations of the heart in Jordanian Arabic (JA) within the framework of Conceptual Metaphor Theory developed by Lakoff and Johnson (1980). The main aim is to explore how the human heart is conceptualized in JA, and to test the applicability of the different general cognitive mechanisms proposed by Niemeier (2003 and 2008) to those found in JA. The data were extracted from Idioms and Idiomatic Expressions in Levantine Arabic: Jordanian Dialect (Alzoubi, 2020), and other resources including articles, dissertations and books of Arabic proverbs. The findings revealed that all the four general cognitive mechanisms suggested by Niemeier (2003 and 2008) are applicable to JA. The findings also showed that the similarity derives from the universal aspects of the human body, which lends tremendous support to the embodiment hypothesis proposed by cognitive linguists. 

scholarly journals Analysis of EEG, Cardiac Activity Status, and Thermal Comfort According to the Type of Cooling Seat during Rest in Indoor Temperature

2020 ◽  
Vol 11 (1) ◽  
pp. 97
Author(s):  
Yunchan Shin ◽  
Minjung Lee ◽  
Honghyun Cho
Keyword(s):  
Thermal Comfort ◽  
Human Body ◽  
Cold Water ◽  
Cardiac Activity ◽  
Satisfaction Level ◽  
Water Cooling ◽  
Indoor Temperature ◽  
Sensorimotor Rhythm ◽  
Electroencephalogram Eeg ◽  
Wave Reduction

In this study, electroencephalogram (EEG) and cardiac activity status of the human body while using various types of seats during rest were analyzed in indoor summer conditions. Thermal comfort was also evaluated through a subjective survey. The EEG, cardiac activity status, and subjective survey during rest indicated that the use of ventilation and cold water-cooling seats was effective. This effectiveness was because of the θ-wave and α-wave activation, sensorimotor rhythm, β-wave reduction, and left hemisphere activation, demonstrating that the conditions applied were suitable for rest. According to the analysis of the subjective questionnaire survey, the use of ventilation and cold water-cooling seats provided a more pleasant state than the basic seat, improving the subject’s warmth and comfort, and also the concentration. In addition, the use of a cold water-cooling seat provided the highest satisfaction level, being the most favorable condition for rest.

XIII. A description of a very unusual formation of the human heart

1798 ◽  
Vol 88 ◽  
pp. 346-356 ◽  
Keyword(s):  
Human Body ◽  
Human Heart ◽  
Natural Form ◽  
Perfect Knowledge ◽  
Learned Societies ◽  
Circulation Of The Blood ◽  
Unusual Formation

T he heart is an organ of so much importance in the animal oeconomy, and is so immediately concerned in the support of life, that any unusual deviation from its natural form and situation in the human body, has always been considered as a subject of some interest by the physiologist; such deviations have, therefore, not unfrequently been submitted to the consideration of this and other learned Societies. Many circumstances respecting the circulation of the blood, and respiration, wholly unknown to our ancestors, have lately been ascertained; but we are not as yet arrived at a perfect knowledge of these important actions. Difficulties yet remain; more information may still be acquired; and the reasoning upon these subjects will be less liable to fallacy, in proportion to the number of facts which have been observed, and the accuracy of the observations.

FREQUENCY RESPONSE OF UWB SIGNAL IN A BEATING HEART

2020 ◽  
pp. 2050041
Author(s):  
Kedar Nath Sahu ◽  
Challa Dhanunjaya Naidu ◽  
Ravindharan Ethiraj ◽  
Jaya Sankar Kottareddygari
Keyword(s):  
Transmission Coefficient ◽  
Pulse Propagation ◽  
Continuous Wave ◽  
Power Transmission ◽  
Cardiac Activity ◽  
Ultra Wideband ◽  
Human Beings ◽  
Rescue Operation ◽  
Modeling And Analysis ◽  
Measurement Monitoring

The measurement, monitoring of heartbeat and its rate are necessary to know the health of the heart of human beings. In addition, they are needed for extended applications like criminal investigation, law enforcement, defense and military usage, search, rescue operation, etc. The ultra-wideband (UWB) radars found growing interest in recent years as they are able to overcome the limitations of continuous-wave (CW) Doppler radars in detecting human heartbeat. Modeling and analysis of the UWB pulse propagation behavior through a human body is important before developing a practical UWB radar. Several researchers have estimated the reflected signals to study if their variations correlate with the heartbeat rate. However, the reflected signal strength carrying Doppler information received at the radar after a two-way propagation of the RF signal was found to be too weak for detection. This paper presents (i) a model for UWB wave propagation through a human thorax and (ii) estimation via simulation, of transmission coefficient at various frequencies in the UWB range 1–10[Formula: see text]GHz using CST Microwave Studio. The study clearly indicates that the variation of power transmission coefficient of UWB signal has a strong correlation to the instantaneous dimension of the heart in a cardiac cycle, a feature that can be exploited in detecting cardiac activity of human being using radar-based principles.

scholarly journals Design of Cavity-Backed Bow-Tie Antenna with Matching Layer for Human Body Application

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 4015 ◽  
Author(s):  
Jeong ◽  
Park ◽  
Lee
Keyword(s):  
Reflection Coefficient ◽  
Human Body ◽  
Electromagnetic Interference ◽  
Impedance Matching ◽  
Human Head ◽  
Impedance Match ◽  
Broadband Antenna ◽  
Matching Layer ◽  
Antenna Performance ◽  
Bow Tie

This paper presents the broadband antenna for the microwave radiometric sensing of internal body temperature. For broadband operation, the bow-tie antenna was designed and backed with a cylindrical cavity, which decreased environmental electromagnetic interference and also improved the directivity of the antenna. The broadband impedance-transforming balun in microstrip form was also designed to feed the bow-tie antenna, and was located inside the cavity. An impedance-matching dielectric layer (IMDL) was introduced on top of the bow-tie antenna, for impedance match with the human body with high permittivity. The fabricated antenna was measured in free space with the IMDL removed, showing an input reflection coefficient lower than −10 dB from 2.64 to > 3.60 GHz with antenna gain over 6.0 dBi and radiation efficiency over 74.7% from 2.7 to 3.5 GHz. The IMDL was re-installed on the cavity-backed bow-tie antenna to measure the antenna performance for the human head with relative permittivity of about 40. The measured reflection coefficient was as low as −28.9 dB at 2.95 GHz and lower than −10 dB from 2.65 to > 3.5 GHz. It was also shown that the designed antenna recovered a good impedance match by adjusting the permittivity and thickness of the IMDL for the different parts of the human body with different permittivities.

Immersive Image Mining in Cardiology

2011 ◽  
pp. 586-592
Author(s):  
Xiaoqiang Liu ◽  
Henk Koppelaar ◽  
Ronald Hamers ◽  
Nico Bruining
Keyword(s):  
Heart Failure ◽  
Virtual Reality ◽  
Data Acquisition ◽  
Human Body ◽  
Human Heart ◽  
Image Mining ◽  
Computational Sciences ◽  
Direct Inspection

Buried within the human body, the heart prohibits direct inspection, so most knowledge about heart failure is obtained by autopsy (in hindsight). Live immersive inspection within the human heart requires advanced data acquisition, image mining and virtual reality techniques. Computational sciences are being exploited as means to investigate biomedical processes in cardiology.

A Microwave Sensor for Contact-Free Measurement of Human Heart Rate

2012 ◽  
Vol 500 ◽  
pp. 325-329
Author(s):  
Guo Hua Lu ◽  
Fang Yang ◽  
Xi Jing Jing ◽  
Xiao Yu ◽  
Hua Wang ◽  
...  
Keyword(s):  
Heart Rate ◽  
Human Body ◽  
Human Heart ◽  
The Body ◽  
Health State ◽  
Rate Measurement ◽  
Remote Sense ◽  
Microwave Sensor ◽  
Contact Free ◽  
Body Comparison

Measures of heart rate are widely used to assess the health state of human in clinic. Tranditional method uses eletrodes touching the body to monitor electrocardiography (ECG) .A micorwave sensor was disscused to remote sense the heart rate without touching human body. Comparison of heart rate derived from the microwave sensor and ECG demonstrated that there were no significant differences, which suggested this sensor may prove a practical alternative to ECG for heart rate measurement.

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