| 1. |
- Asan, Noor Badariah, 1984-, et al.
(författare)
-
Assessment of Blood Vessel Effect on Fat-Intrabody Communication Using Numerical and Ex-Vivo Models at 2.45 GHZ
- 2019
-
Ingår i: IEEE Access. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 2169-3536. ; 7, s. 89886-89900
-
Tidskriftsartikel (refereegranskat)abstract
- The potential offered by the intra-body communication (IBC) over the past few years has resulted in a spike of interest for the topic, specifically for medical applications. Fat-IBC is subsequently a novel alternative technique that utilizes fat tissue as a communication channel. This work aimed to identify such transmission medium and its performance in varying blood-vessel systems at 2.45 GHz, particularly in the context of the IBC and medical applications. It incorporated three-dimensional (3D) electromagnetic simulations and laboratory investigations that implemented models of blood vessels of varying orientations, sizes, and positions. Such investigations were undertaken by using ex-vivo porcine tissues and three blood-vessel system configurations. These configurations represent extreme cases of real-life scenarios that sufficiently elucidated their principal influence on the transmission. The blood-vessel models consisted of ex-vivo muscle tissues and copper rods. The results showed that the blood vessels crossing the channel vertically contributed to 5.1 dB and 17.1 dB signal losses for muscle and copper rods, respectively, which is the worst-case scenario in the context of fat-channel with perturbance. In contrast, blood vessels aligned-longitudinally in the channel have less effect and yielded 4.5 dB and 4.2 dB signal losses for muscle and copper rods, respectively. Meanwhile, the blood vessels crossing the channel horizontally displayed 3.4 dB and 1.9 dB signal losses for muscle and copper rods, respectively, which were the smallest losses among the configurations. The laboratory investigations were in agreement with the simulations. Thus, this work substantiated the fat-IBC signal transmission variability in the context of varying blood vessel configurations.
|
|
| 2. |
- Asan, Noor Badariah, et al.
(författare)
-
Characterization of the Fat Channel for Intra-Body Communication at R-Band Frequencies
- 2018
-
Ingår i: Sensors. - : MDPI. - 1424-8220. ; 18:9
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, we investigate the use of fat tissue as a communication channel between in-body, implanted devices at R-band frequencies (1.7–2.6 GHz). The proposed fat channel is based on an anatomical model of the human body. We propose a novel probe that is optimized to efficiently radiate the R-band frequencies into the fat tissue. We use our probe to evaluate the path loss of the fat channel by studying the channel transmission coefficient over the R-band frequencies. We conduct extensive simulation studies and validate our results by experimentation on phantom and ex-vivo porcine tissue, with good agreement between simulations and experiments. We demonstrate a performance comparison between the fat channel and similar waveguide structures. Our characterization of the fat channel reveals propagation path loss of ∼0.7 dB and ∼1.9 dB per cm for phantom and ex-vivo porcine tissue, respectively. These results demonstrate that fat tissue can be used as a communication channel for high data rate intra-body networks.
|
|
| 3. |
- Asan, Noor Badariah, 1984-, et al.
(författare)
-
Effect of Thickness Inhomogeneity in Fat Tissue on In-Body Microwave Propagation
- 2018
-
Ingår i: Proceedings of the 2018 IEEE/MTT-S International Microwave Biomedical Conference (IMBIOC). - Philadelphia, USA : IEEE. - 9781538659182 ; , s. 136-138
-
Konferensbidrag (refereegranskat)abstract
- In recent studies, it has been found that fat tissue can be used as a microwave communication channel. In this article, the effect of thickness inhomogeneities in fat tissues on the performance of in-body microwave communication at 2.45 GHz is investigated using phantom models. We considered two models namely concave and convex geometrical fat distribution to account for the thickness inhomogeneities. The thickness of the fat tissue is varied from 5 mm to 45 mm and the Gap between the transmitter/receiver and the starting and ending of concavity/convexity is varied from 0 mm to 25 mm for a length of 100 mm to study the behavior in the microwave propagation. The phantoms of different geometries, concave and convex, are used in this work to validate the numerical studies. It was noticed that the convex model exhibited higher signal coupling by an amount of 1 dB (simulation) and 2 dB (measurement) compared to the concave model. From the study, it was observed that the signal transmission improves up to 30 mm thick fat and reaches a plateau when the thickness is increased further.
|
|
| 4. |
- Asan, Noor Badariah, 1984-, et al.
(författare)
-
Effects of Blood Vessels on Fat Channel Microwave Communication
- 2018
-
Ingår i: 2018 IEEE Conference on Antenna Measurements & Applications (CAMA). - : IEEE. - 9781538657959
-
Konferensbidrag (refereegranskat)abstract
- This study aims to investigate the reliability of intra-body microwave propagation through the fat tissue in presence of blood vessels. Here, we consider three types of blood vessels with different sizes. We investigate the impact of the number of blood vessels and their alignment on the transmission of microwave signals through the fat channel. In our study, we employ two probes that act as a transmitter and a receiver. The probes are designed to operate at the Industrial, Scientific, and Medical radio band (2.45 GHz). For a channel length of 100 mm, our results indicate that the presence of the blood vessels may increase the channel path loss by similar to 1.5 dB and similar to 4.5 dB when the vessels are aligned and orthogonally aligned with the fat channel, respectively.
|
|
| 5. |
- Asan, Noor Badariah, 1984-, et al.
(författare)
-
Impact of Blood Vessels on Data Packet Transmission Through the Fat Channel
- 2018
-
Ingår i: 2018 IEEE INTERNATIONAL RF AND MICROWAVE CONFERENCE (RFM 2018). - : IEEE conference proceedings. - 9781538667200 - 9781538667194 - 9781538667217 ; , s. 196-198
-
Konferensbidrag (refereegranskat)abstract
- The reliability of intra-body wireless communication systems is very important in medical applications to ensure the data transmission between implanted devices. In this paper, we present newly developed measurements to investigate the effect of blood vessels on the data packet reception through the fat tissue. We use an IEEE 802.15.4-based WBAN prototype to measure the packet reception rate (PRR) through a tissue-equivalent phantom model. The blood vessels are modelled using copper rods. We measure the PRR at the frequency 2.45 GHz for several power levels. The results revealed that the presence of blood vessels aligned with the fat channel has tiny influence on the PRR when measured over the range -25 dBm to 0 dBm power level and for different blood vessels positions. Our investigations show 97% successful PRR through a 10 cm length fat channel in presence of the blood vessels.
|
|
| 6. |
- Asan, Noor Badariah, 1984-, et al.
(författare)
-
Reliability of the fat tissue channel for intra-body microwave communication
- 2017
-
Ingår i: 2017 IEEE Conference on Antenna Measurements & Applications (CAMA). - : IEEE. - 9781509050284 ; , s. 310-313
-
Konferensbidrag (refereegranskat)abstract
- Recently, the human fat tissue has been proposed as a microwave channel for intra-body sensor applications. In this work, we assess how disturbances can prevent reliable microwave propagation through the fat channel. Perturbants of different sizes are considered. The simulation and experimental results show that efficient communication through the fat channel is possible even in the presence of perturbants such as embedded muscle layers and blood vessels. We show that the communication channel is not affected by perturbants that are smaller than 15 mm cube.
|
|
| 7. |
- Lee, D, et al.
(författare)
-
A preliminary study on monitoring the progression of osteoporosis using UWB radar technique in distal femur model
- 2016
-
Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 0013-5194 .- 1350-911X. ; 52:8, s. 589-590
-
Tidskriftsartikel (refereegranskat)abstract
- In this Letter, the preliminary study on the progression of osteoporosis using ultra wide band radar technique suggesting two different cases, (1) For various bone thickness and (2) For different effective permittivity is presented. To monitor the progression of osteoporosis, resistively loaded dipole antenna was designed and used as a sensor. For use in targets representing intermediate stages of progression, methanol, ethanol, water, and wood were used for emulating effective dielectric constant of bone in real situation. Measurement results show consistent decrease in the enveloped difference voltage in the two cases which correlate to the loss of bone mineral density. In the future, these results will be useful for people with osteoporosis to predict fractures in advance.
|
|
| 8. |
- Mathur, Parul, et al.
(författare)
-
An Efficient Method for Computing the Interaction of Open Ended Circular Waveguide with a Layered Media
- 2018
-
Ingår i: Progress In Electromagnetics Research Letters. - : E M W PUBLISHING. - 1937-6480. ; 76, s. 55-61
-
Tidskriftsartikel (refereegranskat)abstract
- This article presents a new method for studying the near-field electromagnetic interaction between a dielectric filled open ended circular waveguide (OECW) and a layered dielectric structure. The proposed model is based on plane wave spectrum theory using a novel and computationally efficient two step integration method. The first integral, involving multiple singularities in the integration path, is efficiently solved using a deformed elliptical integration path which encircles the singularities of the integral. The infinite domain tail integral involving the slowly converging integrand is further solved using an efficient trigonometric transformation. The proposed OECW based method is capable of determining the unknown material properties of any layered dielectric medium, and hence finds application in nondestructive evaluation of materials.
|
|
| 9. |
- Mohd Shah, Syaiful Redzwan, 1984-, et al.
(författare)
-
Microwave-Sensor-Based Clinical Measurements for Monitoring Post-Craniotomy Bone Development in Pediatric Craniosynostosis Patients
-
Tidskriftsartikel (refereegranskat)abstract
- The bone density analysis system is a new method to analyze the amount of bone healed in cranial vault defects. Craniotomy creates such defects to treat pediatric patients with craniosynostosis. This method uses the variations in the resonance of a microwave sensor attached to the area under test in the patient. Data were collected from infants treated for craniosynostosis through craniotomy surgery in clinical trials. The data, which consist of resonance parameters (frequency, amplitude, and Q-factor) is collected using a microwave-based biomedical sensor. This sensor could detect changes in the resonance as changes in the permittivity of the various tissues at the ISM band. By observing differences between a reference and target defect points, bone healing over time could be accessed. In this paper, we analyze the validity of a proposed Computational Simulation Technology (CST) based numerical model for the sensor and extend the clinical data analysis from previous works with our bone density analysis system. The validity of the model is analyzed by comparing its outcomes to available measurements from numerical simulations, phantoms mimicking living tissues and clinical trial. In the data analysis, a hypothesis is formulated and tested regarding the healing over time. By deriving a set of parameters for each collected dataset in the clinical trials, a distinct pattern was found which shows visible changes such as edema and tissue thickening over the course of the healing process with this technique. Moreover, we manage to distinguish significant differences between the reference and defect points after the craniosynostosis surgery.
|
|
| 10. |
- Perez, Mauricio D., et al.
(författare)
-
Head-compliant microstrip split ring resonator for non-invasive healing monitoring after craniosynostosis-based surgery
- 2020
-
Ingår i: HEALTHCARE TECHNOLOGY LETTERS. - : INST ENGINEERING TECHNOLOGY-IET. - 2053-3713. ; 7:1, s. 29-34
-
Tidskriftsartikel (refereegranskat)abstract
- A soft and highly directive, proximity-coupled split-ring resonator fabricated with a liquid alloy, copper and polydimethylsiloxane (PDMS) is presented. The same was designed for sensing osteogenesis of calvarial bone. As dielectric properties of bone grafts in ossifying calvarial defects should change during the osteogenesis process, devices like this could monitor the gradual transformation of the defect into bone by differentiating changes in the dielectric properties as shifts in the resonance frequency. Computational Software Technology (CST) Microwave Studio (R)-based simulation results on computational head models were in good agreement with laboratory results on head phantom models, which also included the comparison with an in-vivo measurement on the human head. A discussion based on an inductive reasoning regarding dynamics' considerations is provided as well. Since the skin elasticity of newborn children is high, stretching and crumpling could be significant. In addition, due to typical head curvatures in newborn children, bending should not be a significant issue, and can provide higher energy focus in the defect area and improve conformability. The present concept could support the development of soft, cheap and portable follow-up monitoring systems to use in outpatient hospital and home care settings for post-operative monitoring of bone healing after reconstructive surgical procedures.
|
|
