Siya Lozanova

Parallel-Field Silicon Hall Effect Microsensors With Minimal Design Complexity

A new class of Hall microsensors with minimal design complexity was suggested and experimentally tested. The devices consisting in n-Si substrate and three n+-strip contacts only are sensitive to a magnetic field parallel to the chip surface. Using a reference voltage generating with a specific bridge circuitry, the linear Hall voltage is extracted and the quadratic geometrical magnetoresistance is fully compensated. The internal noise of the design with a Hall contact located outside the sensor active region is at least ten times smaller than those of the three-contact element with an inside placed output electrode. This leads to enhanced resolution reaching Bmin ap 35 muT. A three-terminal multisensors generating simultaneously and independently strongly asymmetric voltage to the magnetic field direction and a Hall signal were devised too. The devices performance proved undoubtedly that new three-contact sensors could compete with the other well-known vertical Hall elements.

A framework for design of cloud compatible medical interfaces

A framework for design of novel interfaces for Cloud compatible medical services called User Interface as a Service (UIaaS) is presented in the paper. The aim is to support seamless and ubiquitous health monitoring based on flexible and useful Cloud services for healthcare. The paper describes the methods and new interfaces for health monitoring that have recently been developed for the proposed framework. The influence of the new methods and technologies for future Cloud computing systems for healthcare is discussed.

Cloud Computing Approach to Novel Medical Interface Design

Interface technologies and devices need to be developed with novel functionalities for pattern analysis and data transfer in order to receive helpful and reliable healthcare service “from the Cloud”. The complexity of implementing Cloud computing for healthcare relates to a number of issues such as privacy, data protection, medical record access and update, high performance computation (HPC), etc. [1, 2, 3, 4]. At the same time interoperability needs to be achieved at all levels of provision of Cloud services—from the novel interface, via Hardware as a Service (HaaS), Software as a Service (SaaS) and Infrastructure as a Service (IaaS).

In-plane magnetosensitive double Hall device

A novel in-plane magnetosensitive double Hall sensor, consisting of power supply and two identical three-contact и-Si cross-coupled architectures, realized in common technology process, is presented. High magnetosensitivity as well as increased metrological accuracy is achieved. The residual offset is about 160 times smaller than the internal ones. The obtained output voltage-to-residual offset ratio at magnetosensitivity of 98 V/AT (T = 300 K) is very promising, reaching 7.5×103 at magnetic induction IT.

On the Magnetically Controlled Surface Current at the Hall Structure Sides

The experimentally observed new phenomenon in conducting materials – the magnetically controlled surface current was examined again with an original measuring method and new silicon samples. The obtained results corroborate very well with the previously acquired data. The proposed registration approach utilizes the nulling compensation technique guaranteeing full offset compensation in all operating modes. The connection of the Ettingshausen effect with the new effect is clear demonstrated. A novel pressure sensor using the surface current dependence on external mechanical strain is developed and tested. The output characteristics of this transducer are very well reproducible and are suitable for measurement technologies.

An interface system based on multimodal principle for cardiological diagnosis assistance

A pilot interface system is developed for computer-aided diagnostic and interventional assistance of cardiologists based on clinical trials. The system includes optimized methods for processing and presentation of cardiological knowledge and data. The multimodal principle of the interface is based on know-how tests of a new magnetic microsensor for detection of catheter navigation in images from angiograms and intra-vascular ultrasound and on new investigations of the principle of operation of the electrocardiograph. The user interface includes interactive access to the clinical database and a cognitive approach to disease visualization.