M. van Gils

EEG spectral entropy, heart rate, photoplethysmography and motor responses to skin incision during sevoflurane anaesthesia.

Background:  Analgesia is a part of balanced anaesthesia, but direct indicators of nociception do not exist. We examined the relationship between motor reactions and physiological variables during skin incision in sevoflurane anaesthesia and hypothesized that nociception could be detected and graded by significant changes in these variables.

Estimating Intensity of Physical Activity: A Comparison of Wearable Accelerometer and Gyro Sensors and 3 Sensor Locations

Automatic estimation of physical activity using wearable sensors can be used for promotion of a healthier lifestyle. In this study, accelerometers and gyroscopes attached to ankle, wrist and hip were used to estimate intensity of physical activity. The estimates are compared to metabolic equivalent (MET) obtained from a portable cardiopulmonary exercise testing system. Data from common everyday tasks and exercise were collected with 11 subjects. The tasks include, e.g., ironing, vacuuming, walking, running and cycling on exercise bicycle (ergometer). The strongest linear correlation with metabolic equivalent was obtained with the tri-axial accelerometer attached to the ankle (r=0.86).

Relationship of Psychological and Physiological Variables in Long-Term Self-Monitored Data During Work Ability Rehabilitation Program

Individual wellness comprises both psychological and physiological wellbeing, which are interrelated. In long-term monitoring of wellness, both components should be included. Work-related stress and burnout are persistent problems in industrial countries. Early identification of work-related stress symptoms and early intervention could reduce individual suffering and improve the working productivity and creativity. The goal of this study was to explore the relationship between physiological and psychological variables measured at home by the users themselves or automatically. In all, 17 (3 males and 14 females, age 40-62) people participating in a work ability rehabilitation program (due to work overload) were monitored for three months. Physiological and behavioral variables (activity, bed occupancy, heart rate (HR) and respiration during night, HR during day, blood pressure, steps, weight, room illumination, and temperature) were measured with different unobtrusive wireless sensors. Daily self-assessment of stress, mood, and behaviors (exercise, sleep) were collected using a mobile phone diary. The daily self-assessment of stress and the Derogatis stress profile questionnaire were used as reference for stress status. Results show modest, but significant pooled overall correlations between self-assessed stress level, and physiological and behavioral variables (e.g., sleep length measured with wrist-worn activity monitor: rho = -0.22, p<0.001, and variance of nightly bedroom illumination: rho = 0.13, p<0.001). Strong, but sometimes conflicting correlations can be found at individual level, suggesting individual reactions to stress in daily life.

Application of spectral entropy to EEG and facial EMG frequency bands for the assessment of level of sedation in ICU

The applicability and performance of spectral entropy as a measure of the depth of sedation was studied by comparison to the Richmond sedation and agitation scale (RASS). A biopotential signal was measured from the forehead of eight ICU patients. From this biopotential four different frequency bands were defined using trend fitting to the low and high frequency limits of the pooled power spectra, two frequency bands representing EEG and the other two representing fEMG. The spectral entropy from the EEG bands correlated very well with the sedation levels of RASS. From levels 0 to –5 the decrease was almost linear (r=0.51 and r=0.53). A similar comparison for the spectral entropy of the fEMG bands did not produce any clear correlation (r=0.07 for both fEMG bands), however there was still some clear interaction at some levels. It seems that the RASS is dependent upon both EEG and fEMG effects. That is; RASS is related to both cortical and sub-cortical components of sedation.

Feasibility and user acceptance of a personal weight management system based on ubiquitous computing

With the fast development of information and communications technology, devices with some computing power are becoming increasingly abundant in the average home. The trend for these devices to also be provided with intercommunication functionality opens up new possibilities for health care. The availability of ubiquitous computing allows the individual to perform health-related measurements, review data or consult guidelines independent of place or time, thus providing the individual with a better means to follow certain treatment programs. In this study, we set out to implement a system based on ubiquitous computing for the application of weight management using behavioral feedback. The goals were (a) to gain insights in the technical feasibility and caveats of such a system as a basis for setting up more advanced and generic infrastructures, and (b) to study the degree to whether people are actually willing to use such a technology-laden system for their health management. The results lead us to the conclusion that such a system is possible with the current technology, although many issues need to be solved before generic architectures and implementations are a reality, and that many people, especially those who have serious weight problems, are eager to use such a system.

Propofol versus alfentanil to prevent movement responses during uterine curettage

Background:  Propofol anaesthesia is frequently associated with movement responses in non‐paralysed patients. Opioids decrease the probability of movement during noxious stimulation. Heart rate variability and frontal electromyography (EMG), which are related to subcortical functions, may be more closely related than surface electroencephalography (EEG) to movement responses to noxious stimulation.

Prediction of poor outcome using detector of epileptiform EEG in ICU patients resuscitated after cardiac arrest

Assessing the brain status of patients admitted to intensive care unit (ICU) after out-of-hospital cardiac arrest is challenging. We had earlier found wavelet subband entropy (WSE) to be a useful tool for quantifying the epileptiform content of EEG during anesthesia. In this paper, WSE was applied for EEG of ICU patients to study its prognostic value. During their stay in ICU, EEG was recorded from 20 patients resuscitated after out-of-hospital cardiac arrest. For the analysis, the patients were divided into subgroups of poor outcome (persistent vegetative state, N=4) and good outcome (regain of consciousness, N=16). WSE for each 5-sec segment of EEG was calculated and also the average of WSE for each hour. Also, similar results were calculated for EEG powers in the bands 16-32 Hz and 1-60 Hz to be used as references. The statistical analysis was made by comparing the medians of the distributions of average WSE of each hour between poor and good outcome groups. The median of WSE of poor outcome group was significantly lower than that of good outcome group. The reference indicators did not show significant differences between the groups. The results suggest that WSE can be a valuable prognostic indicator for detecting the patients with poor outcome.

Adherence to Physical Activity in Patients with Heart Disease: Types, Settings and Evaluation Instruments

Physical fitness is one of the main therapeutic recommendations for patients with heart disease. Yet, adherence to physical activity regimen in both daily life and rehabilitation programs remains to be low. Elaborating on the analysis of factors associated with physical activity behavior, we noticed that the concept of adherence is complex, and its evaluation depends on a specific behavior and its settings. Evaluation of adherence to exercise in leisure time and exercise in the settings of cardiac rehabilitation program requires an application of different instruments. In this paper, we present a summary of findings from the literature analysis regarding types, settings and evaluation instruments of physical activity adherence in daily life and cardiac rehabilitation settings.

Medication Incompliance and Vital Signs in Heart Failure Patients

The success of medication treatment is a crucial part of chronic cardiac patients’ therapy. Health professionals are requested to dynamically optimize this procedure (medication initiation, titration, change of medication plans) for each patient. Assessment of the person’s response to treatment, and assessment of adherence to treatment are essential in supporting these medical decisions. In this work, methods that apply biosignal analysis on vital signs data are presented, aiming to detect differences due to medication incompliance. These data, although gathered in controlled conditions, encompass physiological fluctuations introduced by different factors of daily life, such as medication timing and activity. Heart Failure data are normalized to personal levels, and classification models trained with a pair of features (SBP and HR in semirecumbent position) succeed in achieving accuracy over 97% in a crossvalidation setup, in detecting 48 hrs incompliance. Additionally, the differences in incompliance patterns between heart failure and hypertensive subjects are discussed. These results constitute a promising step towards application of vital signs measurement and analysis in homecare for incompliance detection.