| 1. |
- Asan, Noor Badariah, 1984-, et al.
(författare)
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Assessment of Blood Vessel Effect on Fat-Intrabody Communication Using Numerical and Ex-Vivo Models at 2.45 GHZ
- 2019
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Ingår i: IEEE Access. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 2169-3536. ; 7, s. 89886-89900
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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.
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| 2. |
- Mathur, Parul, et al.
(författare)
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An Efficient Method for Computing the Interaction of Open Ended Circular Waveguide with a Layered Media
- 2018
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Ingår i: Progress In Electromagnetics Research Letters. - : E M W PUBLISHING. - 1937-6480. ; 76, s. 55-61
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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.
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| 3. |
- Mohd Shah, Syaiful Redzwan, 1984-, et al.
(författare)
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Microwave-Sensor-Based Clinical Measurements for Monitoring Post-Craniotomy Bone Development in Pediatric Craniosynostosis Patients
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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.
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| 4. |
- Perez, Mauricio D., et al.
(författare)
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Microwave Sensors for New Approach in Monitoring Hip Fracture Healing
- 2017
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Ingår i: 2017 11th European Conference On Antennas And Propagation (EUCAP). - : IEEE. - 9788890701870 ; , s. 1838-1842
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Konferensbidrag (refereegranskat)abstract
- Cyber-Physical System (CPS) applications in lower-extremity bony-fracture rehabilitation systems require real-time biophysical data. Emerging and interesting solutions are microwave approaches that provide good contrast between hard and soft tissues and between local anomalies inside tissues. Preliminarily some contacting non-invasive planar methods have been investigated in their feasibility of detecting human tissues variations with promising results. In this work we introduce two new microwave planar sensors for a new approach of hip fracture healing follow-up tool. They are designed for improved resolution and penetration at frequencies between 1 to 3 GHz in detecting variations in bone, muscle or fat tissues that are expected during a rehabilitation process. The resonant devices are optimized using Frequency Domain Reflectometry and CST (R) environment and validated using clinical trials with volunteers. The new approach is validated using clinical trials with volunteers and patients. These outcomes further emphasize the feasibility of devising systems for fracture rehabilitation.
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| 5. |
- Perez, Mauricio D., et al.
(författare)
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New Approach for Clinical Data Analysis of Microwave Sensor Based Bone Healing Monitoring System in Craniosynostosis Treated Pediatric Patients
- 2018
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Ingår i: 2018 IEEE Conference On Antenna Measurements & Applications (CAMA). - : IEEE. - 9781538657959
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Konferensbidrag (refereegranskat)abstract
- In the BDAS project one of the goals is to provide a solution to the monitoring bone healing issue complementing current techniques. Data have been collected in clinical trials from infants treated for Craniosynostosis by a craniotomy surgery. The data are collected with a biomedical sensor based in microwave technology. This sensor could be able to sense changes in the composition of the different tissues in the upper-hemisphere of the head by noticing a difference in the propagation of the microwaves, as the bone injury from the craniotomy heals over time. In this thesis, we analyse the clinical data in BDAS project incorporating new approaches with respect to previous analysis methods. These new approaches could give new insight into the proposed solution, but more analysis need to be done.
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| 6. |
- Raaben, Marco, et al.
(författare)
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COMplex Fracture Orthopedic Rehabilitation (COMFORT) - Real-time visual biofeedback on weight bearing versus standard training methods in the treatment of proximal femur fractures in the elderly : study protocol for a multicenter randomized controlled trial
- 2018
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Ingår i: Trials. - : BioMed Central (BMC). - 1745-6215. ; 19
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Tidskriftsartikel (refereegranskat)abstract
- Background:Proximal femur fractures are a common injury after low energy trauma in the elderly. Most rehabilitation programs are based on restoring mobility and early resumption of weight-bearing. However, therapy compliance is low in patients following lower extremity fractures. Moreover, little is known about the relevance of gait parameters and how to steer the rehabilitation after proximal femur fractures in the elderly. Therefore, the aim of this prospective, randomized controlled trial is to gain insight in gait parameters and evaluate if real-time visual biofeedback can improve therapy compliance after proximal femur fractures in the elderly.Methods:This is a two-arm, parallel-design, prospective, randomized controlled trial. Inclusion criteria are age >= 60 years, a proximal femur fracture following low energy trauma, and unrestricted-weight bearing. Exclusion criteria are cognitive impairment and limited mobility before trauma. Participants are randomized into either the control group, which receives care as usual, or the intervention group, which receives real-time visual biofeedback about weight-bearing during gait in addition to care as usual. Spatiotemporal gait parameters will be measured in 94 participants per group during a 30-m walk with an ambulatory biofeedback system (SensiStep). The progress of rehabilitation will be evaluated by the primary outcome parameters maximum peak load and step duration in relation to the discharge date. Secondary outcome parameters include other spatiotemporal gait parameters in relation to discharge date. Furthermore, the gait parameters will be related to three validated clinical tests: Elderly Mobility Scale; Functional Ambulation Categories; and Visual Analogue Scale. The primary hypothesis is that participants in the intervention group will show improved and faster rehabilitation compared to the control group.Discussion: The first aim of this multicenter trial is to investigate the normal gait patterns after proximal femur fractures in the elderly. The use of biofeedback systems during rehabilitation after proximal femur fractures in the elderly is promising; therefore, the second aim is to investigate the effect of real-time visual biofeedback on gait after proximal femur fractures in the elderly. This could lead to improved outcome. In addition, analysis of the population may indicate characteristics of subgroups that benefit from feedback, making a differentiated approach in rehabilitation strategy possible.
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| 7. |
- Raaben, Marco, et al.
(författare)
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Innovative Measurement Of Rehabilitation Progress In Elderly With A Hip Fracture : A New Endpoint
- 2018
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Ingår i: 2018 IEEE Conference On Antenna Measurements & Applications (CAMA). - : IEEE. - 9781538657959
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Konferensbidrag (refereegranskat)abstract
- The worldwide ageing population leads to an increase in the incidence of hip fractures in elderly. Weight bearing is important to improve outcome, but rehabilitation is often hampered by the absence of proper rehabilitation tools. The aim of current study is to gain insight in important gait parameters and the rehabilitation progress of elderly with a hip fracture using an innovative biofeedback system (SensiStep). Force measurements were performed in 113 participants during a 30-meter walk with SensiStep. Also, two mobility tests and pain score were assessed in these participants. In 10 participants the measurements were repeated after one year follow up, and 40 healthy volunteers were measured. The parameters peak force and step duration improved towards the end of rehabilitation. A new and objective endpoint of rehabilitation emerges from these two parameters. Moreover, a differentiated approach in rehabilitation could be developed based on the first training session. This could lead to individual rehabilitation programs and thereby improved outcome after hip fractures in elderly.
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| 8. |
- Redzwan Mohd Shah, Syaiful, et al.
(författare)
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Improved Sensor for Non-invasive Assessment of Burn Injury Depth Using Microwave Reflectometry
- 2019
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Ingår i: 2019 13th European Conference on Antennas and Propagation (EuCAP). - 9788890701887
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Konferensbidrag (refereegranskat)abstract
- The European project “Senseburn” aims to develop a non-invasive diagnostic instrument for assessing the depth and propagation of human burns in the clinical scenario. This article introduces an improved flexible microwave split-ring resonator-based sensor, as a new development in this project. The excitation system and the fabrication process are the major improvements with respect to its precedent microwave sensor, both based in polydimethylsiloxane (PDMS) and copper. Both improvements are introduced together with the design of the sensor and of the experimental setup. Human tissue emulating phantoms are designed, fabricated, validated, and employed to emulate different burn depths and to validate the conceptual functionality of the proposed sensor. The Keysight dielectric probe 85070E is employed for the phantom validation. The analysis suggests that the sensor could estimate the burn depth. Future works will be carried out with ex vivo human tissues.
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| 9. |
- Redzwan Mohd Shah, Syaiful
(författare)
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Prospective Applications of Microwaves in Medicine : Microwave Sensors for Orthopedic Monitoring and Burn Depth Assessment
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In recent years, the use of microwave techniques for medical diagnostics has experienced impressive developments. It has demonstrated excellent competencies in various modalities such as using non-ionizing electromagnetic waves, providing non-invasive diagnoses, and having the ability to penetrate human tissues within the GHz range. However, due to anatomical, physiological, and biological variations in the human body, certain obstacles are present. Moreover, there are accuracy problems such as the absence of numerical models and experimental data, difficulty in conducting tests due to safety issues with human subjects, and also practical restrictions in clinical implementation. With the presence of these issues, a better understanding of the microwave technique is essential to further improve its medical application and to introduce alternative diagnostic methods that can detect and monitor various medical conditions in real time.The first part of this thesis focuses on measurement systems for the microwave technique in terms of sensor design and development, numerical analysis, permittivity measurement, and phantom fabrication. The aim is to investigate the feasibility of flexible systems with different fields of application including a microwave sensor system for measuring the healing progression of bone defects present in lower extremity trauma, bone regeneration in craniotomy for craniosynostosis treatments, and dielectric variation for burn injuries. The microwave sensor which utilizes the contrast in dielectric constant between various tissues was used as the primary sensor for the proposed application. This involved detailed optimization of the sensor for greater sensitivity. The experimental work carried out in the lab environment showed that the microwave sensor was able to detect the contrast in dielectric properties so that it can give an indication of the healing status for actual clinical scenarios.The second part of the thesis is making a significant step towards its practical implementation by establishing a system that can detect and monitor the rate of healing progression with fast data acquisition speed of microseconds, and developing an efficient user interface to convert raw microwave data into legible clinical information in terms of bone healing and burn injuries. As an extension to this thesis, clinical studies were conducted and ethical approval for conducting tests on human subjects was obtained for the development of a microwave medical system. The results showed a clear difference in healing progressions due to high detection capability in terms of dielectric properties of different human tissues. All of these contributions enable a portable system to complement existing medical applications with the aim of providing more advanced healthcare systems.
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