ABSTRACT
In the existing walking support system, the range of detection is limited, and it is very difficult to detect obstacles such as a step or a hollow. Therefore, we aim at the development of a new walking support system for a visually-impaired person detecting neighboring obstacles by making use of a smartphone which is a high-performance portable information terminal. In this study, we have developed a walking support system combining the orientation sensor of the smartphone and a small distance sensor at the first stage. When we investigated its precision in detecting an obstacle, it was found that the system could detect obstacles which disturbed the walking of a visually-impaired person such as a step and a wall. We will find an appropriate key to detection to improve the detection precision of the system and make further improvements in the system by trial experiments in the future.
Subject(s)
Smartphone , Walking/physiology , Humans , Self-Help Devices , Telemetry , Visually Impaired PersonsABSTRACT
The numerical whole-body voxel human model (numerical model) developed by National Institute of Information and Communications Technology (NICT) was assumed and hyperthemic treatment using radio-frequency wave was investigated. We assumed 51 different human tissues and organs with 2-mm spatial resolution in the numerical model, inserted it into the resonant cavity applicator, and Maxwell's equations were solved by FDTD method with variable mesh. We obtained the realistic energy patterns for a deep-seated tumor as compared to those obtained in our previous studies.
Subject(s)
Body Temperature Regulation/physiology , Body Temperature Regulation/radiation effects , Electric Stimulation Therapy/instrumentation , Hyperthermia, Induced/instrumentation , Models, Biological , Whole-Body Irradiation/instrumentation , Adult , Computer Simulation , Electromagnetic Fields , Equipment Design , Equipment Failure Analysis , Humans , Japan , Male , Radiation Dosage , Reproducibility of Results , Sensitivity and Specificity , Whole-Body Irradiation/methodsABSTRACT
Maxwell's and heat transfer equations were coupled and solved to determine the heating characteristics of an RF rectangular resonant cavity applicator for hyperthermia before the clinical stage. A simple human model with blood flow and a fat layer was constructed. The region unaffected by tumor was shielded from electromagnetic fields by using conductive caps. The surface of the human model that was exposed to the electromagnetic fields was cooled with pure water bolus. Calculated results show that this applicator can heat a deep-seated tumor.
Subject(s)
Hyperthermia, Induced/instrumentation , Neoplasms/physiopathology , Neoplasms/therapy , Radiofrequency Therapy , Therapy, Computer-Assisted/methods , Adipose Tissue/pathology , Algorithms , Computer Simulation , Computer-Aided Design , Equipment Design , Hot Temperature , Humans , Hyperthermia, Induced/methods , Models, Biological , Models, Statistical , Software , Therapy, Computer-Assisted/instrumentation , TransducersABSTRACT
The heating characteristics of an RF rectangular cavity applicator for hyperthermic treatment that targets deep-seated tumors were investigated numerically and experimentally. In the numerical study, Maxwell's equations and heat transfer equations were solved for a dielectric phantom with and without blood flow. Conductive caps attached to the dielectric phantom to shield the non-tumor regions. The experimental study showed the validity and possibility of heating deep-seated tumors. Thus, the rectangular resonant cavity applicator with an L-type antenna can heat deep-seated tumors.
Subject(s)
Hyperthermia, Induced/instrumentation , Models, Biological , Neoplasms/physiopathology , Neoplasms/therapy , Radiofrequency Therapy , Therapy, Computer-Assisted/methods , Transducers , Computer Simulation , Computer-Aided Design , Equipment Design , Equipment Failure Analysis , Hot Temperature , Humans , Hyperthermia, Induced/methods , Therapy, Computer-Assisted/instrumentationABSTRACT
Electromagnetic and heat-transfer equations were solved to investigate a radio frequency (RF) rectangular resonant cavity applicator. The possibility of heating a deep-seated tumor was demonstrated. A torso-shaped dielectric phantom was made. It has electrical constants resembling those of human muscle. Several L-type antennas were made and placed at appropriate locations to heat a deep region. Measured results agreed with the calculated results. Results show that the rectangular resonant cavity applicator with the L-type antennas can heat deep-seated tumors.
