Ivan Frollo
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Computer Simulation of Calculation Frequency Deviation from Odd Frequency Spectrum Open
The homogeneity of the static magnetic field is crucial for nuclear magnetic resonance (NMR) experiments. The NMR instrumentation is often used to map this field. A spectrum containing information about the static magnetic field is obtaine…
Calculation of the Main Frequency of an NMR Signal from an Even Frequency Spectrum Open
Nuclear magnetic resonance (NMR) measurements are most often used to measure images or display the spectrum of different samples. Depending on the samples, these can be medical applications, chemistry, physics, or mineralogy. Perhaps the m…
Wearable Reflectance PPG Optical Sensor Enabling Contact Pressure and Skin Temperature Measurement Open
This paper describes the design, realization, and application of a wearable sensor based on the photoplethysmography (PPG) principle supplemented with a force-sensitive resistor and a thermometer for the measurement of contact pressure for…
Heart Pulse Transmission Parameters of Multi-Channel PPG Signals for Cuffless Estimation of Arterial Blood Pressure: Preliminary Study Open
The paper describes a method developed for the indirect cuffless estimation of arterial blood pressure (ABP) from two/three-channel photoplethysmography (PPG) signals. It is important when the actual ABPs cannot be measured, e.g., during s…
Contact measurement of skin temperature using a wearable two-channel PPG optical sensor supplemented by thermometers Open
This paper describes realization, basic properties, testing, and experiments with a special prototype of a wearable two-channel photoplethysmography (PPG) sensor supplemented by contact thermometers that maps the skin temperature at the pl…
Wearable Two-Channel PPG Optical Sensor with Integrated Thermometers for Contact Measurement of Skin Temperature Open
Many factors affect photoplethysmography (PPG) signal quality, one of them being the actual temperature of the skin surface. This paper describes the process of design, realization, and testing of a special wearable PPG sensor prototype wi…
Analysis of Heart Pulse Transmission Parameters Determined from Multi-Channel PPG Signals Acquired by a Wearable Optical Sensor Open
The article describes the development and testing of a special prototype wearable device consisting of three optical photoplethysmography (PPG) sensors. The functionality of the developed triple PPG sensor was tested under normal laborator…
Conversion of the Bruker Minispec Instrumentation into the Static Magnetic Field Standard Open
The static magnetic field standard is part of many scientific experiments aimed at measuring the magnetic field. Often this device has to be built by oneself, if there is no possibility to buy it off the shelf. One possibility is also to c…
Experiment with Cuffless Estimation of Arterial Blood Pressure from the Signal Sensed by the Optical PPG Sensor Open
The paper describes the development, testing, and verification of practical usability of the indirect cuffless method for estimation of arterial blood pressure (ABP) values from the photo-plethysmography (PPG) signal sensed by the optical …
Comparison of Three Prototypes of PPG Sensors for Continual Real-Time Measurement in Weak Magnetic Field Open
This paper is focused on investigation of three developed prototypes of sensors based on the photoplethysmography (PPG) principle for continual measurement of the PPG signal in the magnetic field environment with the inherent radiofrequenc…
Analysis of NMR Signal for Static Magnetic Field Standard Open
This article describes the analysis of the NMR (Nuclear Magnetic Resonance) stabilizer signal. Magnetic field of the standard is created using an electromagnet. Sufficiently high stability of the magnetic field is achieved with the help of…
Stress Level Detection and Evaluation from Phonation and PPG Signals Recorded in an Open-Air MRI Device Open
This paper deals with two modalities for stress detection and evaluation—vowel phonation speech signal and photo-plethysmography (PPG) signal. The main measurement is carried out in four phases representing different stress conditions for …
Two Realizations of the Wearable PPG Sensor Working in Reflectance Mode for Measurement in Weak Magnetic Field Open
The paper describes and compares properties of two realizations of wearable sensors based on the photoplethysmography (PPG) principle for non-invasive acquisition of the human heart rate. The designed sensors enable measurement of the PPG …
Calibration of NMR Receiver using Spectrometer Characteristics Open
This article describes the measurement of the relation between input and output signals using two techniques: with a signal generator and with the thermal noise of a known resistance. Each of the techniques has its advantages and disadvant…
A Theoretical Analysis of Magnetic Particle Alignment in External Magnetic Fields Affected by Viscosity and Brownian Motion Open
The interaction of an external magnetic field with magnetic objects affects their response and is a fundamental property for many biomedical applications, including magnetic resonance and particle imaging, electromagnetic hyperthermia, and…
Comparative Measurement of the PPG Signal on Different Human Body Positions by Sensors Working in Reflection and Transmission Modes Open
The paper deals with the photoplethysmographic (PPG) optical sensor usage for non-invasive acquisition of vital information about the cardiovascular system from different parts of the human skin surface. Finger-ring and ear-clip realizatio…
Effects of contrast agents on relaxation properties of <sup>31</sup>P metabolites Open
Purpose Phosphorous MR spectroscopy ( 31 P‐MRS) forms a powerful, non‐invasive research tool to quantify the energetics of the heart in diverse patient populations. 31 P‐MRS is frequently applied alongside other radiological examinations, …
Sensitivity Analysis of the Simply Noise-matched Receiving Coil for NMR Experiments Open
The article analyzes the sensitivity of unmatched receiving coil for the NMR scanner. Receiver of the scanner was investigated from the point of view of noise features. Theory of the noise figure has been modified to utilize the receiver f…
Multinuclear MRS at 7T Uncovers Exercise Driven Differences in Skeletal Muscle Energy Metabolism Between Young and Seniors Open
Purpose: Aging is associated with changes in muscle energy metabolism. Proton (1H) and phosphorous (31P) magnetic resonance spectroscopy (MRS) has been successfully applied for non-invasive investigation of skeletal muscle metabolism. The …
First-Step PPG Signal Analysis for Evaluation of Stress Induced during Scanning in the Open-Air MRI Device Open
The paper describes first-step experiments with parallel measurement of cardiovascular parameters using a photoplethysmographic optical sensor and standard portable blood pressure monitors in different situations of body relaxation and sti…
Importance of Basset History Force for the Description of Magnetically Driven Motion of Magnetic Particles in Air Open
Lungs are used as an attractive possibility for administration of different therapeutic substances for a long time. An innovative method of such administration widely studied nowadays is the application of aerosolized magnetic particles as…
Measurement Science is the Science of Sciences - There is no Science without Measurement Open
Omnia in mensura et numero et pondere disposuisti is a famous Latin phrase from Solomon’s Book of Wisdom , dated to the mid first century BC, meaning that all things were ordered in measure, number, and weight. Naturally, the wisdom is app…
Physiological Impact of Vibration and Noise in an Open-Air Magnetic Resonance Imager: Analysis of a PPG Signal of an Examined Person Open
The paper represents a preliminary analysis of the physiological and psychological impact of vibration and acoustic noise on a person examined by a low-field magnetic resonance imaging (MRI) tomograph. First, a methodology for the measurem…
Analysis of the Influence of Different Settings of Scan Sequence Parameters on Vibration and Noise Generated in the Open-Air MRI Scanning Area Open
A system of gradient coils of the magnetic resonance imaging (MRI) device produces significant vibration and noise. Energetic relations of these phenomena are analyzed depending on MRI scan parameters (sequence type, repetition time (TR), …
Analysis of Energy Relations between Noise and Vibration Produced by a Low-Field MRI Device Open
Magnetic resonance imaging (MRI) tomography is often used for noninvasive scanning of various parts of a human body without undesirable effects present in X-ray computed tomography. In MRI devices, slices of a tested subject are selected i…
Analysis of NMR Spectrometer Receiver Noise Figure Open
This article describes the measurement and evaluation of the system noise figure of a nuclear magnetic resonance spectrometer. A method was used which involved the console of the spectrometer, calibrated for real voltage (in volts), and us…
Analysis of Energy Relations between Noise and Vibration Signals in the Scanning Area of an Open-Air MRI Device Open
The paper analyzes the influence of different magnetic resonance (MR) scan sequence parameters (echo time, repetition time, orientation of scan slices, sequence type, mass of a tested object) on the energy of the produced noise and vibrati…
Analysis of Influence of Coil Gradient System on Vibration Properties and Acoustic Noise Level Generated by the Low Field MRI Device Open
The paper focuses on investigation of influence of the volume inserted in the scanning area of the magnetic resonance imaging (MRI) device working with a low magnetic field generated by a pair of permanent magnets on vibration and acoustic…
Design and Construction of Novel Instrumentation for Low-Field MR Tomography Open
Magnetic resonance imaging (MRI) is a very popular tool for diagnostic applications and research studies. Low-field MR scanners, usually with an open design, are suitable for claustrophobic and obese patients, as well as for children, who …
Vibration and Noise in Magnetic Resonance Imaging of the Vocal Tract: Differences between Whole-Body and Open-Air Devices Open
This article compares open-air and whole-body magnetic resonance imaging (MRI) equipment working with a weak magnetic field as regards the methods of its generation, spectral properties of mechanical vibration and acoustic noise produced b…