Through an integration of wireless communication and sensing technologies, the concept of a body sensor network (BSN) was initially proposed in the early decade with the aim to provide an essential technology for wearable, ambulatory, and pervasive health monitoring for elderly people and chronic patients. It has become a hot research area due to big opportunities as well as great challenges it presents. Though the idea of an implantable BSN was proposed in parallel with the on-body sensor network, the development in this area is relatively slow due to the complexity of human body, safety concerns, and some technological bottlenecks such as the design of ultralow-power implantable RF transceiver. This paper describes a new wireless implantable BSN that operates in medical implant communication service (MICS) frequency band. This system innovatively incorporates both sensing and actuation nodes to form a closed-control loop for physiological monitoring and drug delivery for critically ill patients. The sensing node, which is designed using system-on-chip technologies, takes advantage of the newly available ultralow-power Zarlink MICS transceiver for wireless data transmission. Finally, the specific absorption rate distribution of the proposed system was simulated to determine the in vivo electromagnetic field absorption and the power safety limits.

Abstract-Retinal prosthesis system is currently being developed in various places around the world. This system involved data transfer between an implanted antenna inside an eyeball and an external camera that is located just in front of the eyeball. While there are plenty of publications about the stimulating electrodes or the processing unit of the system itself, very limited amount has been published regarding the wireless communication link between the two antennas despite the fact that the electromagnetic wave will propagate through a complex medium in the form of Vitreous Humor. This paper will discuss about the constraints associated with implanting an antenna into an eyeball. An antenna design and simulation was performed with the aid of High Frequency Structure Simulator (HFSS) and its Finite Element Method (FEM) mathematical solver in the operating frequency of 402-405 MHz. The antenna, which was a 4 layer microstrip antenna, was positioned at the centre of a spherical model filled with homogeneous Vitreous Humor material. Antenna performances that include return loss, bandwidth, gain, radiation pattern, and SAR value are analysed and compared against those of other implantable antennas operating in Medical Implant Communication Service (MICS) band. Free space and simulating fluid measurements were also conducted on the fabricated antenna to validate the simulation results. It was concluded that the fabricated antenna was able to produce the similar performance to the simulation results and hence at the same level as the other antennas operating in material with lower dielectric constants and conductivities.

Retinal Prosthesis has developed to a more advanced stage with the support of advancing technologies. However, there have not been enough details about the wireless mechanism within the system even though it is accountable for the information transmission from the camera to the electrodes and also the complexity of the process itself due to the challenging environments. This paper will discuss about a design of high performance antenna that suits the challenging condition of the implantable devices. Its performance will then be compared with similar antennas that have been proposed or built previously.

With the advancement of implantable technology in the sensory world, new possibilities to improve the quality of human life have started to emerge. A wireless implantable body sensor network is a concept that has been studied for over a decade, where multiple different implantable sensors are integrated to create a network. The network relies on wireless links as the mean of communication between the sensor and actuator nodes through challenging medium of human tissues. In this paper, a microstrip antenna was designed to accommodate the constraints incurred by the human tissues environment and to provide a reliable transmission at 402 MHz frequency. A multi-layer human arm was used as the model and the simulation was run with High Frequency Structure Simulator (HFSS) software. Antenna parameters including return loss, gain, radiation pattern, and SAR values were obtained from the simulation as the reference value for future in vitro or in vivo experiments. Index Terms-microstrip antenna, implantable, wireless body sensor network, MICS band978-1-4673-5936-8/13/$31.00 ©2013 IEEE

The recent development in retinal prostheses brings the hope to restore the vision of blind people. Currently, research efforts have been largely focused on improving the electrode array of the system. However, the electromagnetic exposure to the surrounding area inside a human head caused by the implanted antenna system has been often overlooked. The authors investigate the specific absorption rate distributions inside a multilayer human head model for three implantable rectangle spiral microstrip antennas operating at different frequency bands as well as for one inductive coil antenna, which is popularly used for near‐field data and power telemetry. The simulation results, which were obtained by using computer simulation technology Microwave Studio software, suggest that the Medical Implant Communication Service frequency band is the most suitable frequency choice for the currently proposed implanted retinal prosthesis systems. However, with the increase of stimulation electrode density, a higher frequency band might have to be chosen in the future to accommodate the increased bandwidth requirement.