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The EnSitetrade intracavitary probe system developed by Endocardial Solutions, Inc (St. Jude Medical, St. Paul, MN) was used to simultaneously record geometric information, probe potentials, and selected endocardial potentials within the right atria for four patients. Tikhonov regularization was then used to estimate endocardial potentials from probe measurements for each patient at each endocardial...
This paper presents a wireless ballistocardiographic chair developed for the Proactive Health Monitoring project in the Institute of Signal Processing. EMFi sensors are used for BCG measurement and IEEE 802.15.4 RF link for radio communication between the chair and a PC. The chair measures two BCG signals from the seat and the backrest and a rough ECG signal from the armrests of the chair. The R-spike...
We present a novel instrumentation system for studying tendon and spinal reflexes using a commercial linear servo-motor as a precisely controlled tendon hammer. The system uses a LabVIEW-based program to both control electrical or mechanical stimuli and record and measure the resulting M and H waves. The hammer can deliver tendon taps with selected velocities, durations, frequencies and excursions...
Coil systems have been a standard for measuring eye movements. These systems, which have been designed to work at low frequencies (20 KHz), generally require large field coils so that a uniform field can be established at the eye coil site. This configuration makes it virtually impossible to study eye movements in freely moving animals. In this paper, we describe the design of a coil system, which...
The radio frequency field used in magnetic resonance imaging (MRI) procedures leads to temperature and local absorption rate (SAR) increase for patients with implanted pacemakers (PM). In this work a methodological approach for temperature and SAR measurements using fluoroptic probes is presented. Experimental measures show how the position of temperature probes affects the temperature and SAR value...
Rhinomanometry includes a set of methodologies to diagnose pathological alterations of the nostrils and nasal cavities. Some anatomic variations could cause partial or sub total obstruction of one or both nostrils, leading to insufficient nasal respiration. Rhinomanometry measures the airflow through one nostril at time, while a pad occludes the other. This method has some drawbacks, such as the alteration...
An instrumented bicycle pedal was built and calibrated. The pedal has good linearity and sensibility, comparable to other instruments in the literature. This study aimed to perform accurate calibration of a tri-axial pedal, including forces applied, deformations, nonlinearities, hysteresis and standard error for each axis. Calibration was based on Hull and Davis method, which is based on the application...
In this paper we introduce our conception of a two-channel bioimpedance monitor for the impedance cardiography. We describe the design of a homemade device which is based on a direct digital synthesizer and a digital down converter. This solution enables us to obtain a high-quality bioimpedance signal, which can be used for computing the cardiac output beat per beat. It further enables us to analyze...
A microneedle array has been fabricated and applied to the measurement of transdermal skin potentials in human subjects. Potential changes were recorded in the vicinity of superficial wounds, confirming the generation of a lateral electric field in human skin. The measured electric field decays with distance from the wound edge, and is directed towards the wound. The measurement of endogenous fields...
The long term goal of our research is to develop a tool for recognizing human emotions during e-learning processes. This could be accomplished by combining quantitative indexes extracted from non-invasive recordings of four physiological signals: namely skin conductance, blood volume pulse, electrocardiogram and electroencephalogram. Wearable, non-invasive sensors, communicating with a PC, were applied...
System miniaturization and steady progress towards a totally implantable prosthetic system is the current trend in cochlear implant technology. To achieve this objective, the external microphone of present implants needs to be implantable. This goal can be accomplished by placing a miniature accelerometer on the ossicular chain in the middle ear to detect and convert bone vibrations into an electrical...
In this study we explored the possibility to realize a low power device for Cardiac Output continuous monitoring based on impedance cardiography technique. We assessed the possibility to develop a system able to record data allow an intra-subjective analysis based on the daily variations of this measure. The device was able to acquire and to send signals using a wireless Bluetoothreg transmission...
Wearable accelerometry provides easily portable systems that supply real-time data adequate for gait analysis. When they do not provide direct measurement of a spatio-temporal parameter of interest, such as step length, it has to be estimated with a mathematical model from indirect sensor measurements. In this work we are concerned with the accelerometry-based estimation of the step length in straight...
Spasticity is often seen in patients with central nervous system lesion, such as stroke. It hinders functional movement and may induce pain. Current measures for assessing Spasticity are either quantitative but not convenient to use or convenient to use in clinics but lack of objective quantification. We developed a manual spasticity evaluator (MSE) to evaluate the spasticity quantitatively and potentially...
In this paper, we investigated the validity of the WHAM (wearable heart activity monitor) in the clinical applications, which has been implemented as a wearable ambulatory device for continuously and long-term monitoring user's cardiac conditions. To this end, using the WHAM and the conventional Holter monitor the ECG signals over 24 hours were recorded during daily activities. The signal from the...
Spasticity is often seen in patients with central nervous system lesion, such as stroke. It hinders functional movement and may induce pain. Current measures for assessing Spasticity are either quantitative but not convenient to use or convenient to use in clinics but lack of objective quantification. We developed a manual spasticity evaluator (MSE) to evaluate the spasticity quantitatively and potentially...
The radio frequency field used in magnetic resonance imaging (MRI) procedures leads to temperature and local absorption rate (SAR) increase for patients with implanted pacemakers (PM). In this work a methodological approach for temperature and SAR measurements using fluoroptic probes is presented. Experimental measures show how the position of temperature probes affects the temperature and SAR value...
Daily long-term monitoring of heart rates is important for health management. An analysis of heart rate variability can facilitate the early discovery of illnesses. In this study, we paid attention to the method of measuring resting heart rate over long term. An acceleration sensor was set inside the down kilt as it opposing to subject's left chest. Mechanical vibration from heart activity is carried...
This paper investigates a two-channel Doppler radar sensor that can provide information on the direction of movement. The radar sensor has the advantage of non-invasive, contactless measurements, compared to ultrasound. From theoretical considerations and a working model, we deduce a criterion for extracting points of no movement in a heart cycle. We propose to use this criterion to characterize the...
In this paper, we investigated the validity of the WHAM (wearable heart activity monitor) in the clinical applications, which has been implemented as a wearable ambulatory device for continuously and long-term monitoring user's cardiac conditions. To this end, using the WHAM and the conventional Holter monitor the ECG signals over 24 hours were recorded during daily activities. The signal from the...
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