Dr. Amani Yousef Owda Profile

Dr. Amani Yousef Owda

at Arab American Univ

SPIE Involvement:

Author

Publications (6)

Proceedings Article | 17 October 2023 Presentation + Paper

A three-layer model for investigating the effect of clothing made of fleece, denim, and leather on the interaction of millimetre wave radiation on the skin

Amani Yousef Owda, Neil Salmon, Majdi Owda

Proceedings Volume 12740, 127400K (2023) https://doi.org/10.1117/12.2679140

KEYWORDS: Extremely high frequency, Skin, Data modeling, Transmittance, Electromagnetism, Computer security, Biomedical applications, Systems modeling, Reflectivity, Millimeter wave sensors

Read Abstract +

This paper proposes a three-layer electromagnetics model for investigating the interaction of millimetre wave radiation with human skin and clothing as a means to improve security screening technology. Progress in this spectral band is only possible with a deep understanding of the interaction of this radiation with the human body, the clothing and threat items; the proposed model in this paper is implemented to provide us with this information. The model consists of three layers namely, 1) air (a semi-infinite layer and lossless layer), 2) clothing layer (finite thickness layer ranging from 0.0 mm-1.2 mm), and 3) skin layer (semi-infinite layer). Three types of clothing are investigated by the model, these being: 1) Fleece, 2) Denim, and 3) Leather. Simulation results indicate that a clothing layer, in direct contact with human skin, enhances the transmission of radiation between air and skin. This is due to the clothing layer acting as an impedance matching transformer. The simulation results indicate that the power transmission coefficient varies with the frequency and thickness of the clothing layer. For the Fleece, the power transmission coefficient was found to increase fractionally, ranging from 0.05 to 0.112 at 90 GHz when the thickness of the fleece varied between 0.5mm and 1.2 mm. For the Denim, the difference in the transmission coefficient was found to increase with the thickness of the Denim, up to a factor of 0.095, when the thickness of the Denim layer varied from 0.5 mm to 1.2 mm at 60 GHz. For the beige leather, the variation in the transmission coefficient between different thicknesses was substantial and it could be up ~10.0% when the thickness of the material varied from 0.5 mm to 1.0 mm at 60 GHz. However, when the thickness of the leather was 1.2 mm, the maximum value of the transmission coefficient of 0.83 was achieved at around 45 GHz. Simulation results obtained from the three-layer model presented in this paper are in good agreement with the measurements reported in the literature reviews at specific frequencies. The importance of having such a validated model is that security screening system parameters can be optimised with a minimal amount of costly trials and experimentation.

Proceedings Article | 7 December 2022 Presentation + Paper

Porcine skin as a surrogate for human skin in millimetre wave sensing research

Amani Yousef Owda, Neil Salmon, Majdi Owda

Proceedings Volume 12274, 122740W (2022) https://doi.org/10.1117/12.2635339

KEYWORDS: Skin, Reflectivity, Calibration, Radiometry

Read Abstract +

Improving the security screening requires good knowledge and understanding of human skin signatures. Our previous publications indicate that the signature of the human skin varies from person to person under a dry and wet state. Human skin is a very sensitive organ and not all material can be applied or attached directly to the skin. Therefore, it is an essential requirement to find a close surrogate i.e. (animal tissue) and characterise similarities in signature between human and animal skin. The importance of this is that it will allow us to investigate more easily signatures of the human skin under different materials and conditions. This paper investigates signatures for the human skin and ex-vivo porcine skin samples using the 90 GHz calibrated radiometer. The paper aims to compare and show similarities and differences in the signature between human and ex-vivo porcine skin samples for the first time using millimetric wave radiometry. To this end, water and different types of cream were applied to the palm of the hand and porcine skin samples namely: skin with water jel, skin with silver sulfadiazine cream, and skin with betadine cream. The reflectance of the skin was measured before and after the application, with and without the presence of a clothing layer. Reflectance measurements on human skin were applied on six participants in the palm of the hand region for comparison with reflectance measurements of porcine skin from six samples taken from the back region of different animals. Reflectance measurements for the palm of the hand skin show that the mean reflectance values for all six participants are: 0.458, 0.618, 0.578, 0.548, and 0.488 for normal skin, skin with water, skin with water jel, skin with silver sulfadiazine cream, and skin with betadine cream respectively. For porcine skin samples, the mean reflectance values for all six samples are: 0.438, 0.608, 0.598, 0.558, and 0.508 for normal skin, skin with water, skin with water jel, skin with silver sulfadiazine cream, and skin with betadine cream respectively. These measurements indicate the similarities between the palm of the human hand and the back region of swine. The measurements also show that the difference in the mean reflectance values between the palm of the hand region and porcine skin for all cases is ~0.02. After adding a clothing layer made of textiles on the palm of the hand skin and porcine skin samples; the reflectance measurements for the palm of the hand skin become 0.408, 0.545, 0.498, 0.488, and 0.458 for normal skin, skin with water, skin with water jel, skin with silver sulfadiazine cream, and skin with betadine cream respectively. For porcine skin samples the mean reflectance values are: 0.388, 0.518, 0.488,0.488, and 0.478 respectively. These measurements indicate that textiles are relatively transparent over the frequency band (80-100) GHz and the signature of the skin can be observed through clothing. The increased understanding of these measurements brings means research into the medical applications of millimetre wave imaging to assess wounds under dressings. More specifically, subjects bearing bandaged wounds could be screened more reliably using imagers. In addition to the security screening applications and anomalies detection.

Proceedings Article | 12 September 2021 Presentation + Paper

Indoor passive sensing for detecting hidden objects under clothing

Amani Yousef Owda, Neil Salmon, Majdi Owda

Proceedings Volume 11868, 118680P (2021) https://doi.org/10.1117/12.2597640

KEYWORDS: Metals, Imaging systems, Extremely high frequency, Information security, Passive remote sensing, Skin, Receivers, Radiometry, MATLAB, Electromagnetism

Read Abstract +

Proceedings Article | 20 September 2020 Presentation + Paper

Millimetric radiometry for measuring human and porcine skin reflectance

Amani Yousef Owda, Neil Salmon

Proceedings Volume 11541, 115410G (2020) https://doi.org/10.1117/12.2576376

Read Abstract +

Despite the rising interest in the human skin signature over the millimetre wave band there is relatively little information about the human skin reflectance and the dielectric properties of the human skin, and how these varying with locations and between gender, and hydration level of the skin. This paper has investigated the reflectance of the human skin over the frequency band 80-100 GHz, and comparing the reflectance of the human skin with the reflectance of porcine skin samples under normal and wet skin conditions. For a sample of 60 healthy participants (36 males and 24 females) the mean reflectance of the skin over all measurement locations was found to be ~0.606 with a standard deviation of ~0.086. The skin regions of the palm of the hand, the outer wrist and the dorsal forearm skin had reflectances 0.068, 0.058 and 0.0677 lower than the skin regions of the back of the hand, the inner wrist and the volar forearms respectively. Reflectance measurements of human skin under normal and wet state on the palm of the hand and the back of the hand regions indicate that the mean differences in the reflectance before and after the application of water is ~0.15 and ~0.075 respectively. A comparison in reflectance between human skin and porcine skin samples indicates similar trends in signatures between ex-vivo porcine skin samples and human skin. During the cycle of life, human skin is affected by many factors such as the age, the environment, the interaction with different types of radiation, genetic defects, dehydration, and accidents. These factors might cause diseases, temporal skin conditions, and permanent disorders. In response to this, the skin presents signatures, which can be measured using non-contact millimetre wave sensors that could quantify the degree of the damage. These unique findings enable millimetre wave radiometry to be used for detecting human skin signatures and anomalies under different conditions by identify unusually high or low levels of reflectance in tens of seconds.

Proceedings Article | 18 October 2019 Paper

Variation in the electromagnetic signatures of the human skin with physical activity and hydration level of the skin

Amani Owda, Neil Salmon

Proceedings Volume 11164, 1116402 (2019) https://doi.org/10.1117/12.2533162

KEYWORDS: Skin, Radiometry, Calibration, Antennas, Extremely high frequency, Receivers, Reflectivity, Temperature metrology, Electromagnetism, Radiation effects

Read Abstract +

Our recent studies in the human skin signatures indicate a strong correlation between the human skin emissivity and factors such as the body mass index, the gender, the age, and the ethnicities of the participants. The key innovation in this is in recognising that signatures from the human body enable regions of the body to be identified as skin. This will enable increased the detection probabilities of anomalies, and reduced the false alarm rates in security screening portals. This is a capability that is being demanded internationally by governments and in the UK by the Home Office Future Aviation Security Solutions (FASS) programme and the Joint Security and Resilience Centre (JSaRC).

In this paper, radiometric measurements conducted on human skin in the millimetre wave band region (80-100) GHz show variation in the human skin emissivity before and after conducting physical activity (jogging) subject to the same participant. The measurements were conducted on the palm of the hand and the back of the hand skin. The measurements reveal that the emissivity of the skin is significantly lower in the rest state of the body compared with the active state by mean values of 0.088 and 0.07 for the palm of the hand and the back of the hand skin respectively. The differences in the mean emissivity values were found to be linked to the length of time exercising and the hydration level of the skin i.e. (sweat). Radiometric measurements on palms of the hand and on the back of the hand skin before and after the application of an aqueous gel indicate a strong correlation between the human skin signature and the hydration level of the skin. The mean differences in emissivity values before and after the application of an aqueous gel indicate a scatter in the range of 0.02 to 0.26. These findings suggested trends in the human skin emissivity and indicate the potential of a new non-contact passive method for remote sensing of the physical state of human beings. Understanding these signatures and variations of the human skin emissivity are very important for both security screening (anomalies detection) and medical applications (non-invasive diagnosis of human body).

Proceedings Article | 6 October 2017 Paper

Signatures of human skin in the millimetre wave band (80-100) GHz

Amani Owda, Nacer-Ddine Rezgui, Neil Salmon

Proceedings Volume 10439, 1043904 (2017) https://doi.org/10.1117/12.2292046

KEYWORDS: Skin, Calibration, Radiometry, Antennas, Extremely high frequency, Liquids, Nitrogen, Receivers, Metals, Temperature metrology

Read Abstract +

With the performance of millimeter wave security screening imagers improving (reduced speckle, greater sensitivity, and better spatial resolution) attention is turning to identification of anomalies which appear on the human body. Key to this identification is the understanding of how the emissive and reflective properties vary over the human body and between different categories of people, defined by age and gender for example. As the interaction of millimetre waves with the human body is only a fraction of a millimetre into the skin, precise measurement of the emission and reflection of this radiation will allow comparisons with the norm for that region of the body and person category. On an automated basis at security screening portals, this will increase detection probabilities and reduce false alarm rates, ensuring high throughputs at entrances to future airport departure lounges and transport networks. A technique to measure the human skin emissivity in vivo over the frequency band 80 GHz to 100 GHz is described. The emissivities of the skin of a sample of 60 healthy participants (36 males and 24 females) measured using a 90 GHz calibrated radiometer was found to range from 0.17±0.002 to 0.68±0.002. The radiometric measurements were made at four locations on the arm, namely: palm of hand, back of hand, dorsal surface of the forearm, and volar side of the forearm, where the water content and the skin thickness are known to be different. These measurements show significant variation in emissivity from person to person and, more importantly, significant variation at different locations on the arms of individuals. Males were found to have an emissivity 0.03 higher than those of females. The emissivity of the back of the hand, where the skin is thinner and the blood vessels are closer to the skin surface, was found to be lower by 0.0681 than the emissivity of the palm of the hand, where the skin is thicker. The measurements also show that the emissivity of the volar side location where the blood vessels are closer to the skin surface is lower by 0.0677 than the emissivity of the dorsal surface location. The measured differences agree with those differences estimated by a half space electromagnetic model of the interaction and can be interpreted in terms of the differing water contents and skin thickness of those regions of the body.

Showing 5 of 6 publications

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years