K. Abbas

Neonatal non-contact respiratory monitoring based on real-time infrared thermography

BackgroundMonitoring of vital parameters is an important topic in neonatal daily care. Progress in computational intelligence and medical sensors has facilitated the development of smart bedside monitors that can integrate multiple parameters into a single monitoring system. This paper describes non-contact monitoring of neonatal vital signals based on infrared thermography as a new biomedical engineering application. One signal of clinical interest is the spontaneous respiration rate of the neonate. It will be shown that the respiration rate of neonates can be monitored based on analysis of the anterior naris (nostrils) temperature profile associated with the inspiration and expiration phases successively.ObjectiveThe aim of this study is to develop and investigate a new non-contact respiration monitoring modality for neonatal intensive care unit (NICU) using infrared thermography imaging. This development includes subsequent image processing (region of interest (ROI) detection) and optimization. Moreover, it includes further optimization of this non-contact respiration monitoring to be considered as physiological measurement inside NICU wards.ResultsContinuous wavelet transformation based on Debauches wavelet function was applied to detect the breathing signal within an image stream. Respiration was successfully monitored based on a 0.3°C to 0.5°C temperature difference between the inspiration and expiration phases.ConclusionsAlthough this method has been applied to adults before, this is the first time it was used in a newborn infant population inside the neonatal intensive care unit (NICU). The promising results suggest to include this technology into advanced NICU monitors.

Phonocardiography Signal Processing

Abstract The auscultation method is an important diagnostic indicator for hemodynamic anomalies. Heart sound classification and analysis play an important role in the auscultative diagnosis. The term phonocardiography refers to the tracing technique of heart sounds and the recording of cardiac acoustics vibration by means of a microphone-transducer. Therefore, understanding the nature and source of this signal is important to give us a tendency for developing a competent tool for further analysis and processing, in order to enhance and optimize cardiac clinical diagnostic approach. This book gives the reader an inclusive view of the main aspects in phonocardiography signal processing. Table of Contents: Introduction to Phonocardiography Signal Processing / Phonocardiography Acoustics Measurement / PCG Signal Processing Framework / Phonocardiography Wavelets Analysis / Phonocardiography Spectral Analysis / PCG Pattern Classification / Special Application of Phonocardiography / Phonocardiography Acoustic Im...

Hybrid optical imaging technology for long-term remote monitoring of skin perfusion and temperature behavior

Abstract. Photoplethysmography imaging (PPGI) and infrared thermography imaging (IRTI) are contactless camera-based measurement methods for monitoring a wide range of basic vital parameters. In particular, PPGI enhances the classical contact-based photoplethysmography. Approved evaluation algorithms of the well-established PPG method can easily be adapted for detection of heart rate, heart rate variability, respiration rate (RR), respiratory variability (RV), and vasomotional activity with PPGI. The IRTI method primarily records temperature distribution of the observed object, but information on RR and RV can also be derived from IRTI by analyzing the development of temperature distribution in the nasal region. The main advantages of both monitoring methods are unobtrusive data acquisition and the possibility of assessing spatial assignment between vital parameters and body region. Hence, these methods enable long-term monitoring or the monitoring of effects with special local characteristics. Because the two systems supplement each, a combined hybrid application is proposed and its feasibility discussed.

Non-Contact Respiratory Monitoring Based on Real-Time IR-Thermography

Vital signal monitoring based on Infrared thermography is a new growing field of biomedical engineering. One important vital signal of interest in a clinical diagnosis system is the respiration rate that can be monitored based on the skin temperature profile associated with inspiration and expiration of the subject. This work presents a new respiration monitoring method that utilizes region-of-interest (ROI)-processed infrared thermography images. A wavelet-based analysis method is introduced in order to identify a thermal variation zone which is cooled by expiratory airflow. Based on wavelet-decomposition, the overall performance of respiration monitoring showed a good performance in 8 tested adult subjects and one infant.

Infrared thermography for detailed registration of thermoregulation in premature infants.

Abstract Objective: To evaluate skin temperature by using different positions with non-contact infrared thermography (IRT) in multiple body areas of preterm infants for detailed information about temperature regulation and distribution. Methods: The temperature of ten premature infants (median: 27 weeks; age 36 days; weight 1322 g) was determined via IRT (leg, back, arm, head, upper abdomen; diameter 1 cm, scale 0.00°C), and comparison was made with two conventional sensors. There were measurements of 10 min each: first incubator phase (I1), standardized skin-to-skin care (SSC) at the beginning (SSC1), after 90 min (SSC2), and then there was a second incubator phase (I2). Results: From I1 to SSC1, patients cooled down (max. 0.62°C; both methods). From SSC1 to SSC2 temperature on central areas (abdomen, back) was maintained but rose distinctively on the head and leg (P<0.05). In the incubator (I2), temperature niveau in all IRT-areas was significantly lower than before SSC. Conclusion: Via IRT, it is possible to detect fluctuations in temperature of premature infants. The cooling in I2 after SSC should be taken into account before routine daily care.

Non-contact monitoring techniques - Principles and applications

This work gives an overview about some non-contact methods for monitoring of physiological activity. In particular, the focus is on ballistocardiography, capacitive ECG, Infrared Thermography, Magnetic Impedance Monitroing and Photoplethymographic Imaging. The principles behind the methods are described and an inside into possible medical applications is offered.

Intelligent neonatal monitoring based on a virtual thermal sensor

BackgroundTemperature measurement is a vital part of daily neonatal care. Accurate measurements are important for detecting deviations from normal values for both optimal incubator and radiant warmer functioning. The purpose of monitoring the temperature is to maintain the infant in a thermoneutral environmental zone. This physiological zone is defined as the narrow range of environmental temperatures in which the infant maintains a normal body temperature without increasing his or her metabolic rate and thus oxygen consumption. Although the temperature measurement gold standard is the skin electrode, infrared thermography (IRT) should be considered as an effortless and reliable tool for measuring and mapping human skin temperature distribution and assist in assessing thermoregulatory reflexes.MethodsBody surface temperature was recorded under several clinical conditions using an infrared thermography imaging technique. Temperature distributions were recorded as real-time video, which was analyzed to evaluate mean skin temperatures. Emissivity variations were considered for optimal neonatal IRT correction for which the compensation vector was overlaid on the tracking algorithm to improve the temperature reading. Finally, a tracking algorithm was designed for active follow-up of the defined region of interest over a neonate’s geometry.ResultsThe outcomes obtained from the thermal virtual sensor demonstrate its ability to accurately track different geometric profiles and shapes over the external anatomy of a neonate. Only a small percentage of the motion detection attempts failed to fit tracking scenarios due to the lack of a properly matching matrix for the ROI profile over neonate’s body surface.ConclusionsThis paper presents the design and implementation of a virtual temperature sensing application that can assist neonatologists in interpreting a neonate’s skin temperature patterns. Regarding the surface temperature, the influence of different environmental conditions inside the incubator has been confirming.

System Identification of Neonatal Incubator based on Adaptive ARMAX Technique

The existence of thermal disturbance like opening of incubator clapper was considered as principal cause for possible significant incubator heat loss; therefore understanding this phenomenon is definitely essential for optimal design of a neonatal incubator. This study investigates the effect of instantaneous thermal disturbances on convective heat flux from surrounding environment to inside the incubator. Real-time temperature data was collected inside incubator from five points according to the IEC-60601standards, using high sensitive RTD sensors with 0.01°C temperature resolution. The thermal dynamic properties of neonatal incubator were evaluated using adaptive system identification. The experiment was conducted using inline adaptive auto regressive moving average with exogenous input (ARMAX) algorithm, which was embedded in computation loop using LabVIEW®-System identification toolkit. Temperature gradient effect of single measurement point and convective heat transfer of neonatal incubator were determined. System dynamics of accurate and precise sensors response were obtained for spatial temperature distribution inside incubator. Relative humidity of corresponding points was computed using Magnus approximation. Dynamic model of incubator was obtained by varying heat flux to the incubator. Disturbance model was obtained by measuring incubator clappers opening, which is implemented by using potentiometer hinged with clapper. The derived model was tested and approved using linear regression analysis.

Mitral Regurgitation PCG-Signal Classification based on Adaptive Db-Wavelet

an auscultation method is an important diagnostic indicator for hemodynamic anomalies. Heart sound classification and analysis play an important role in the auscultative diagnosis. This study uses a combination of wavelet decomposition of continuous transform for systolic and diastolic pattern; with a combination of system identification based on ARMAX techniques to efficiently extract the features for pre-processed heart sound in order to classify and estimate hemodynamic properties of the heart. A system was developed for the interpretation of heart sounds acquired by phonocardiography using wavelet decomposition. As an advanced method to integrate the automated auscultation computer aided diagnosis (CAD). The task of feature extraction was performed using three methods: time domain feature, Short-Time Fourier Transforms (STFT) and Debauchies methods and ARMAX. The performances of these feature extraction methods were then compared and interpreted.

Thermoregulation of Premature Infants during and after Skin-to-Skin Care.

OBJECTIVE Providing normothermia is an important issue in daily routine care of premature neonates. We recently found with infrared thermography (IRT) a drop in skin temperature of premature babies after they were positioned from skin-to-skin care (SSC) back into the incubator. Since this did not disappear within 10 min, we wanted to find out how long it takes until the baby has fully warmed up after SSC and if the IRT measurements correlate with conventional rectal temperature? STUDY DESIGN A prospective observational study was undertaken with 5 premature infants [3 male, median gestational age 28 weeks (25-29), median age at study 34 d (28-52), median birth weight 898 g (400-1095), median weight at study 1263 g (790-1465)], temperature was determined with IRT (leg, back, arm, head, upper abdomen; diameter 1 cm, scale 0.00°C), comparison with 2 conventional sensors and rectal temperature. Temperatures were recorded every 2 min and displayed for 4 time points, namely at the beginning and the end of skin-to-skin care (SSC1, SSC2), as well as at the beginning and the end of a subsequent 60 min incubator period (I). RESULTS A significant rise during SSC occurred while the cooling after SSC persisted during the complete incubator measurement time (I; p<0.05). Rectal temperature remained stable through the whole measuring period. CONCLUSION While SSC in our setting led to an increase in temperature, the lack of compensation of peripheral heat loss in the incubator after 60 min may express an inadequate peripheral regulation of body temperature. This should be taken into account before routine care after SSC.