Adam Bujnowski

Gdansk University of Technology · Department of Biomedical Engineering

Postoperative tissue flap vitality monitoring enables early detection of clinical complications, allowing for intervention. Timely re-operation can prevent the need for extensive correction procedures, thus reducing healthcare costs and hospitalization time. Statistics show that monitoring can increase the success rate of flap survival to 95% or hi...

Capacitive electrocardiography (cECG) is most often used in wearable or embedded measurement systems. The latter is considered in the paper. An optimal electrocardiographic lead, as an individual feature, was determined based on model studies. It was defined as the possibly highest value of the R-wave amplitude measured on the back of the examined...

The precise mechanisms connecting the cardiovascular system and the cerebrospinal fluid (CSF) are not well understood in detail. This paper investigates the couplings between the cardiac and respiratory components, as extracted from blood pressure (BP) signals and oscillations of the subarachnoid space width (SAS), collected during slow ventilation...

An applicability of a remote (contactless) electrocardiogram (ECG) measurements in a bathtub is presented in the paper. Possibility of ECG measurements in shallowly filled tube with a water was examined. A bathing person was, both, sitting and lying during experiments performed. The problem became non-trivial when the bathing person was moving in r...

The scope of this paper is analysis of applicability of modern biomedical acquisition system installed in bathtub towards reception of respiratory signals of bathing person. An analysis of the possibility of such measurement is shown as well as preliminary results.

An unobtrusive, noninvasive and continuous pressure measurement is invaluable however, still being under research and development. There are many attempts proposing an appropriate relationship between pulse pressure velocity and pressure. Fifteen different formulas, both theoretical and experimental, describing relation between blood pressure and c...

The purpose of this paper is to explore elders' perspectives about self-monitoring and using specially developed sensor technology for measuring health indicators. The qualitative research method is focus-groups with guidelines that were designed for understanding elder's requirements about monitoring health indicators. We present them two devices:...

The paper presents an alternative approach to the monitoring of the cardiovascular system. The study depicts configurations of the utilized system and preliminary results of electrical and mechanical parameters of the cardiac system which can be measured using a head-worn device.

The paper presents a preliminary meta-analysis of the sample correlation between pulse arrival time (PAT) and blood pressure (BP). The aim of the study was to verify sample correlation coefficient between PAT and BP using an affine model $ BP = a . PAT+b $ for systolic and diastolic blood pressure. The databases included in the search were the IEEE...

Presented device -a scale developed for enabling extra measurements, in addition to body weight and composition, the electrical activity of the heart (electrocardiogram - ECG) and the level of oxygen saturation in the blood SaO2. Electrical activity is recorded in the form of six leads, so-called. limb leads. The device allows measurement of all st...

A typical galvanic-connected electrocardiogram (ECG) measurement system utilizes two signal’s electrodes and a third one in driven-right-leg (DRL) circuit for improving a common-mode rejection ratio(CMRR) of the acquisition system. In capacitive-coupled ECG similar techniques are used, however it is expected, that the utilized DRL subsystem is form...

An influence of a human body position on ECG derived respiration (EDR) signal is presented in the paper. Examinations were performed during deep, suspended and normal breathing for eight people in four different body positions. EDR and thoracic impedance signals were compared using correlation and standard deviation coefficients. Obtained results h...

A novel approach for monitoring a temperature distribution inside a tissue during thermoablation is presented in the paper. A thermal profile is measured using a set of serially connected thermistors each bypassed by a capacitor. This technique allows a two-wire and simultaneous multi-point measurements using a multi-frequency measurement of electr...

This paper presents the methods of diversified touchless interactions between a user and a mobile platform utilizing the optical gesture sensor. The sensor uses 8 photodiodes to measure the reflected light in the active mode (using embedded LEDs) or it measures shadows caused by fingers in the passive mode. Several algorithms were implemented: auto...

In this paper we deal with the problem of precise gesture recognition for the active optical proximity sensor with sparse 8 photodiodes. We particularly focus on developing the method of estimating the real, usually not observable, maximum signal value representing maximum intensity of light reflected from an obstacle present in the front of the se...

In this paper we present the possibility of using eGlasses eye tracking module as an extension for Scratch programming tool which is a visual programming language supporting computer skills learning. The main concept behind this project is to setup the interface for rapid interaction design. Eye tracking is a powerful tool for hands free communicat...

In this study we evaluated system architecture for the use of smart glasses as a viewer of information, as a source of medical data (vital sign measurements: temperature, pulse rate, and respiration rate), and as a filter of healthcare information. All activities were based on patient/device identification procedures using graphical markers or feat...

In this paper we investigate the effectiveness of the interaction using eye tracking and electromyography. Smart glasses requires reliable interfaces for controlling the graphic content displayed directly in front of the user's eye. Presented research is related with the eGlasses project, which is focused on the development of an open platform in t...

In this preliminary study we analyzed the possibility of the reliable measurement of biomedical signals with some potential hardware extensions of smart glasses. Using specially designed experimental prototypes four category of biomedical signals were measured: electrocardiograms, electromyograms, electroencephalograms and respiration waveforms. Ex...

We propose the use of smart glasses to collaborate with smart objects in the Internet of Things environment. Particularly we are focusing on new interaction methods and the analysis of acceptable reaction times in the process of object recognition using smart glasses. We evaluated the proposed method using user studies and experiments with three di...

Human Body Communication is an attractive alternative for traditional wireless communication (Bluetooth, ZigBee) in case of Body Sensor Networks. Low power, high data rates and data security makes it ideal solution for medical applications. In this paper, signal attenuation for different frequencies, using FR4 electrodes, has been investigated. Per...

A new approach for item marking using two dimensional discrete graphics markers. Proposed solution allow to change the code rapidly, upon request and in the case of thermal markers make the code invisible for unauthorized observers. Connecting the proposed codes with wearable multmedial platform such as eGlasses can create new possibilities in huma...

In this exploratory study 13 adult test subjects have performed different food intake tasks while wearing a three axis accelerometer mounted at a temple of glasses. Two different algorithms for task recognition have been applied and compared. The retrospective data processing leads to better task recognition results when the frequency range of 50 H...

Recently, different smart glasses solutions have been proposed on the market. The rapid development of this wearable technology has led to several research projects related to applications of smart glasses in healthcare. In this paper we propose a general architecture of the system enabling data integration for the recognized person. In the propose...

Two methods of object position and movement estimation in relation to the user of smart glasses were investigated. An active infrared and ultrasonic methods of the obstacle detection were presented and compared. Application of these methods depend on active transducers type (physical medium used), geometry and surface properties of detected objects...

Obstructive sleep apnea (OSA) is a condition of cyclic, periodic obstruction (stenosis) of the upper respiratory tract. OSA could be associated with serious cardiovascular problems, such as hypertension, arrhythmias, hearth failure or peripheral vascular disease. Understanding the way of connection between OSA and cardiovascular diseases is importa...

Obstructive sleep apnea usually requires all-night examination in a specialized clinic, under the supervision of a medical staff. Because of those requirements it is an expensive and a non-widely utilized test. Moving the examination procedure to patients' home with automatic analysis algorithms involved will decrease the costs and make it availabl...

In this paper we present a new human-computer interface for the quantitative measurement of blowing activities. The interface can measure the air flow and air pressure during the blowing activity. The measured values are stored and used to control the state of the graphical objects in the graphical user interface. In speech therapy children will fi...

A Sudden Cardiac Death (SCD) is a death resulting from cardiac failure with no significant symptoms earlier than one hour before occurrence. It is the cause of for approximately 400000 deaths per year in United States and millions of deaths worldwide. The proposed system, including two-stage algorithm and wearable diagnostic device allows for SCD r...

Implicit interaction combined with object recognition techniques opens a new possibility for gathering data and analyzing user behavior for activity and context recognition. The electronic eyewear platform, eGlasses, is being developed, as an integrated and autonomous system to provide interactions with smart environment. In this paper we present a...

An influence of head movements on the gaze estimation accuracy when using a head mounted eye tracking system is discussed in the paper. This issue has been examined for a multi-display environment. It was found that head movement (rotation) to some extent does not influence on the gaze estimation accuracy seriously. Acceptable results were obtained...

Diagnosis of obstructive sleep apnea usually involves polysomnographic analysis, which unfortunately requires overnight stay in a specialized clinic and is very uncomfortable for a patient. This paper describes the method and apparatus for recording a set of signals to detect sleep apnea. The device records the following signals simultaneously: thr...

A practical application of a bioimpedance technique for a detection of a bathing person is presented in the paper. It addresses the possibility of supervising people in the bathtub without voiding of their intimacy. The measurement system installed in a fiber-glass or a plastic bathtub is able to detect a presence of the bathing person, to estimate...

This paper presents the enhanced remote control and its role in pervasive health care in the home. The device was equipped with health-related measurement modules and a message-processing unit. Preliminary results are presented for monitoring of a pulse, hand tremors, grip forces, and for self-evaluation procedures. The interaction of the device wi...

An example of an infra-red remote control device is presented in this paper. The device is equipped with additional medical diagnostic features for physiological and mental training. It is primarily a diagnostic health-care unit to support the elderly. To improve the acceptance of the device, the additional features are hidden in the shape of an or...

Disorders of the heart and blood vessels are the leading cause of health problems and death. Early detection of them is extremely valuable as it can prevent serious incidents (e.g. heart attack, stroke) and associated complications. This requires extending the typical mobile monitoring methods (e.g. Holter ECG, tele-ECG) by introduction of integrat...

Health monitoring at home could be an important element of the care and support environment for older people. The diversity of diseases and different needs of users require a universal design of a home platform. We present our work on a sensor-based multimodal platform which is designed to recognize the activities an elderly person performs in thei...

Ageing of the population in developed countries is a major problem and a challenge not only from a social or an economic point of view, but it is also a challenge for engineers, as in the near future there maybe a lack of personnel to take care of the elderly. There is an expectation that the gap in this field might be filled by some electronic dev...

Dichromacy is a serious color vision problem, where people can see and recognize only a limited number of colors. In this article we propose computerized methods and systems for processing of WWW images and pictures obtained using a camera phone. Image simulation, transformation and color vision difference visualization methods are presented as a p...

Monitoring system for detection of person and his/her activity in the bathroom is described in the paper. It also detects and monitors person taking bath. The system consists of sensors measuring humidity, air and water temperature, spilled water, and state of bathtub. The bathtub state detector (BSD) allows controlling water level and its temperat...

Health monitoring at home could be an important element of care and support environment for older people. Diversity of diseases and different needs of users require universal design of a home platform. We present our work on a sensor-based multimodal platform that is trained to recognize the activities elderly person on their home. Two specific pro...

An electrode matrix and electronic circuit for simultaneous monitoring heart performance and respiration activity is described in the paper. The heart performance is evaluated basing on a mechanical and electrical activity. The mechanical activity is measured using bioimpedance method while the electrical one using a typical approach, i.e. one chan...

In the article a distributed supervisory system is presented. The system consists of a set of the measurement nodes to track and supervise the most common domestic media consumption. The main goal of the system is to determine activity of the habitants. This has been achieved by means of electrical energy, water and gas consumption tracking. Severa...

Cardiac resynchronization therapy (CRT) is a very promising treatment for patients with congestive heart failure. An Impedance Cardiography (ICG) is used for evaluation of heart mechanical activity. A simulation study with the use of a FEM model was performed. The developed realistic model of the thorax, based on CT data obtained from examination o...

A multichannel impedance and one lead electrocardiographic recording system has been developed. The impedance measurement unit is built using a four-electrode technique. It consists of a sinusoidal, 40 kHz, current source and five measurement channels. Circumferential current electrodes have been located at a neck and an abdomen. Voltage measuremen...

A Dual Frequency EIT is an extension of a traditional EIT that uses two sinusoidal signals for imaging. Appropriate selection of signals' frequency allows to achieve reasonable contrast of imaged structure. It has already been shown that frequency of the signals should cover a selected dispersion range (usually a beta dispersion) for living biologi...

A usefulness of a developed probe combining power delivery to ablated breast tumour and simultaneous impedance measurements is discussed in the paper. It consists of a cylindrical electrode used for applying ablation current and four rings electrodes. They are located, in pairs, at both ends of the ablation electrode. The probe properties were exam...

This article presents the tryout of increasing computer and internet security by means of complementing the authentication procedure with the gaze tracking. The eyes of the person who is being identified follow the point on the computer screen and eye movement tracking system is used to collect information about eye movements during the experiment....

This article presents the tryout of increasing computer and internet security by means of complementing the authentication procedure with the gaze tracking. The eyes of the person who is being identified follow the point on the computer screen and eye movement tracking system is used to collect information about eye movements during the experiment....

Recently, an attempt to monitor elders, disabled and/or convalescent people at home has been an emerging discipline of technology and science. Especially, providing a home care based on remote sensing for single and elder persons is a challenging task. An integrated sensor for cardiac, breathing and kinetics of movement activities is developed. It...

A design of an ergonomic and user-friendly pointing device for elderly people enabling them to operate a traditional windows-based operating system is presented in the paper. To mimic a more natural way of pointing at various things on the computer screen the traditional interface was combined with the gaze control pointing device. The gaze trackin...

In this paper methods for image simulation as seen by a color blinded and a method for constructing images of perceived color difference are presented. The work is also focused on the interactive color description of an image contents. As a result, the individuals having problems with color discrimination can identify colors in an image.

The aim of our study was the evaluation of a pressure prediction method, which was based on Taylor series. The pressure value was predicted basing on its past values, which were weighted by coefficients calculated according to the Taylor series approximation. The advantage of such approach was possibility of non-uniform pressure measurements. The m...

Health monitoring at home could be an important element of care and support environment for older people. Diversity of diseases and different needs of users require universal design of a home platform. In this work the design of multimodal platform for communication, training and patient monitoring at home is presented and discussed. Two specific p...

The paper introduces a project conducted to create a complex human computer interface based on restricted head movements, eye blinks and the wrist rotation.

Two different methods of sensitivity calculation are presented in the paper. A first approach is based on analytical description of the potential creating by current flowing between two point electrodes. A second approach is based on finite element approximation of Biot-Savart relationship. The former approach appears a very fast and relatively acc...

A reconstruction algorithm is presented in the paper. It is a joint method based on electrical and magnetic measurements. The sensitivity function was calculated using the method proposed by Kotre, Biot-Savart and Geselowitz formulae. The achieved simulation results proved feasibility of the proposed method.

This paper describes real-time daylight based eye gaze tracking system. Proposed solution consists of two video cameras, infrared markers and few electronic components. Usage of popular webcams makes the system inexpensive. In dual camera system one camera is used for pupil tracking while second one controls position of the head relative to the scr...

A measurement technique for evaluation of processes occurring in the myocardium during blood flow arrest is presented. The system is devoted to monitoring the myocardium state during off-pump coronary artery by-pass grafting, i.e. during a surgical operation performed on a beating heart. A substantial part of the system is a probe whose constructio...

Paper presents the design and preliminary studies on vibrotactile method used to guide a blind person in the urban space. A very simple and effective method has been developed. It contains of two vibrators, especially developed control hardware and software. Properties of the proposed system were examined by visually impaired and normal persons usi...

This paper describes real-time daylight based eye gaze tracking system. Proposed solution consists of two cameras, infrared markers and few electronic components. Usage of the popular Web cams makes the system inexpensive. In dual camera system one camera is used for pupil tracking while second one controls position of the head relative to the scre...

Two methods of a cursor movement controlling are presented. They are based on detecting an eye position or its fixation. The method based on detection the fixation appeared very fast and relatively inaccurate in opposition to the method based on controlling the eye position.

Originally, tissue stabilizer has been developed by Medtronic, Inc. It is used to prevent a certain part of myocardium from moving. For example, such an approach is utilized during Coronary Artery Bypass Grafting (CABG). Moreover, medical procedures during such operations involve blood arrest, thus, potentially may involve ischemia of myocardium. A...

Resistance and spontaneous electrical activity have been recorded during experimentally induced ischemia of swine heart performed on 9 pigs. Ischemia has been obtained by occlusion the left anterior descending coronary artery (LAD). Four waveforms of electrogram (EG), one electrocardiographic (ECG) -time reference signal- and two waveforms of resis...

An improved method of the dual frequency dif-ferential impedance tomography is presented. The improve-ment involves pre-measurement stage, where according to the object properties optimal frequencies and amplitudes of the excitation signal selection are proposed.