Gaddi Blumrosen

Enhancing RSSI-based tracking accuracy in wireless sensor networks

In recent years, the demand for high-precision tracking systems has significantly increased in the field of Wireless Sensor Network (WSN). A new tracking system based on exploitation of Received Signal Strength Indicator (RSSI) measurements in WSN is proposed. The proposed system is designed in particular for WSNs that are deployed in close proximity and can transmit data at a high transmission rate. The close proximity and an optimized transmit power level enable accurate conversion of RSSI measurements to range estimates. Having an adequate transmission rate enables spatial-temporal correlation between consecutive RSSI measurements. In addition, advanced statistical and signal processing methods are used to mitigate channel distortion and to compensate for packet loss. The system is evaluated in indoor conditions and achieves tracking resolution of a few centimeters which is compatible with theoretical bounds.

Enhanced calibration technique for RSSI-based ranging in body area networks

Indoor positioning systems based on Received Signal Strength Indicator (RSSI) in Wireless Sensor Networks (WSNs) are commonly used. The position accuracy in these systems is highly affected by the wireless medium variability, and therefore, a precise calibration is necessary to translate the power measurements to corresponding distance between each pair of nodes. In this paper, we propose a calibration scheme that is tailored to Body Area Networks (BANs) applications. The a priori knowledge about the environment conditions in these applications can increase the accuracy of the localization system, improve its robustness to interference, and reduce the number of RSSI measurements which are required for the calibration process compared to the traditional calibration methods. We define a criterion to obtain the calibration scheme using different a priori knowledge for both the mapping table and the path-loss model parameters. For evaluation of our new calibration scheme, we conducted a series of experiments in a real-world indoor environment, focusing on a proximate environment that is commonly used in BANs. We showed that for a tracking application, calibration methods utilizing the a priori knowledge are superior in terms of localization accuracy over other existing calibration methods with relatively small number of offline measurements.

Noncontact Tremor Characterization Using Low-Power Wideband Radar Technology

Continuous monitoring and analysis of tremor is important for the diagnosis and establishment of treatments in many neurological disorders. This paper describes noncontact assessment of tremor characteristics obtained by an experimental new ultrawideband (UWB) system. The system is based on transmission of a wideband electromagnetic signal with extremely low power, and analysis of the received signal, which is composed of many propagation paths reflected from the patient and its surroundings. A description of the physical principles behind the technology, a criterion, and efficient algorithms to assess tremor characteristics from the bulk UWB measurements are given. A feasibility test for the technology was conducted using a UWB system prototype, an arm model that mimics tremor, and a reference video system. The set of UWB system frequencies and amplitudes estimations were highly correlated with the video system estimations with an average error in the scale of 0.1 Hz and 1 mm for the frequency and amplitude estimations, respectively. The new UWB-based system does not require attaching active markers or inertial sensors to the body, can give displacement information and kinematic features from multiple body parts, is not limited by the range captured by the optical lens, has high indoor volume coverage as it can penetrate through walls, and does not require calibration to obtain amplitude estimations.

C-SMART: Efficient seamless cellular phone based patient monitoring system

This work describes the design of a new mobile health (mHealth) platform for a continuous real time remote patient monitoring named C-SMART. The platform is based on a set of sensors for patients physiological condition assessment, a mobile phone, and a centralized healthcare utility. C-SMART is implemented on application layer and thus can be compatible to different existing telemedicine and medical data base standards in particular to IEEE 11073. A major concern in the design of the system is given to exploit existing hardware and software resources and thus reduce the platform overhead with minimal user intervention and minimal cost. Another main concern in the design is to make the platform working in a plug and play manner, but yet to give the user maximum control on the system operation. It is enabled by forming a dedicated remote control and installation center and by using an operation menu at the mobile phone. A feasibility test to the platform demonstrated human activity monitoring through a standard mobile phone and a set of accelerometers, and programming of the sensors through the mobile phone.

New Wearable Body Sensor for Continuous Diagnosis of Internal Tissue Bleeding

Continuous monitoring of internal bleeding in tissue is essential for assessment and treatment of medical conditions. In this study we present a new body sensor for diagnosis of internal tissue bleeding based on contact multi-frequency electromagnetic inductive measurements of the tissue. This contributes to the existing family of body network sensors. This sensor can be used in emergency medicine in the field, in a hospital, or during daily life for patients at risk of bleeding. Unlike other sensors that detect bleeding, this sensor is portable, low cost, non-invasive and does not require galvanic coupling between the electrode and the tissue under measurement. Our study includes description of the new body sensor, criteria for data processing, basic diagnostic algorithms and calibration techniques. We show feasibility of this new sensor with a sensor prototype and diagnosis of an experimental simulation of internal bleeding and hypoperfusion conditions in the brain.

Tremor Acquisition System Based on UWB Wireless Sensor Network

This work suggests to quantify and analyze tremorusing an Ultra Wide-Band (UWB) Wireless Sensor Network(WSN). WSN based on UWB technology provides a new technology for non contact tremor assessment with extremely low radiation and penetration through walls. Tremor is the target symptom in the treatment of many neurological disorders such as Parkinson’s disease (PD), midbrain tremor, essential tremor (ET) and epilepsy. The common instrumental approaches for the assessment of tremor are motion capture devices and video tracking systems. The new tremor acquisition system is based on transmission of a wideband electromagnetic signal from multiple sensor nodes placed indifferent locations in a home and analysis of the received signal in each sensor node. The sensors can exchange information between each other with a coded transmission or send the raw data to a UWB hub for further analysis. The data can be then sent by an internet gateway to a health care center for monitoring and for medical care. This paper describes the basic system and gives a fundamental detection technique. For a feasibility test we built an UWB based sensor node prototype and examined its performance with an arm model that fluctuated in the range of clinical tremor frequencies (3-12 Hz). A future development of this work can lead to a low cost monitoring system installed at any home, hospital or school to continuously assess and report tremor conditions during daily life activities.

Non-contact UWB Radar Technology to Assess Tremor

This work quantifies and analyzes tremor using Ultra Wide Band (UWB) radio technology. The UWB technology provides a new technology for non contact tremor assessment with extremely low radiation and penetration through walls. Tremor is the target symptom in the treatment of many neurological disorders such as Parkinson’s disease (PD), midbrain tremor, essential tremor (ET) and epilepsy. The common instrumental approaches for the assessment of tremor are motion capture devices and video tracking systems. The new tremor acquisition system is based on transmission of a wideband electromagnetic signal with extremely low radiation, and analysis of the received signal composed of many propagation paths reflected from the patient and its surroundings. An efficient UWB radar detection technique adapted to tremor detection is developed. Periodicity in the time of arrival of the received signal is detected to obtain tremor characteristics. For a feasibility test we built an UWB acquisition system and examined the performance with an arm model that fluctuated in the range of clinical tremor frequencies (3-12 Hz). A devlpoment of this work can lead to a monitoring system installed at any home, hospital or school to continuously asses and report tremor conditions during daily life activities.

Exploitation of electromagnetic radiation properties for medical diagnostic

A modern health system increasingly relies on modern sensing tools to aid in patient care. This paper suggests exploiting accessible electromagnetic radiation properties of propagation delay, attenuation and dispersion to extract biomedical parameters and to assess medical conditions continuously, in a non-invasive way, and with a minimal cost. It is performed by employing a set of sensors equipped with wireless capabilities that transmit to the medium of interest a known pattern of electromagnetic radiation. From the partial reception of the signal at the sensors, parameters like tremor characteristics, distance between body parts, and tissue bleeding indicator, can be derived and then used for medical diagnosis.