Hanne Opsahl Austad

ESUMS: A mobile system for continuous home monitoring of rehabilitation patients

The pressure on the healthcare services is building up for several reasons. The ageing population trend, the increase in life-style related disease prevalence, as well as the increased treatment capabilities with associated general expectation all add pressure. The use of ambient healthcare technologies can alleviate the situation by enabling time and cost-efficient monitoring and follow-up of patients discharged from hospital care. We report on an ambulatory system developed for monitoring of physical rehabilitation patients. The system consists of a wearable multisensor monitoring device; a mobile phone with client application aggregating the data collected; a service-oriented-architecture based server solution; and a PC application facilitating patient follow-up by their health professional carers. The system has been tested and verified for accuracy in controlled environment trials on healthy volunteers, and also been usability tested by 5 congestive heart failure patients and their nurses. This investigation indicated that patients were able to use the system, and that nurses got an improved basis for patient follow-up.

Development of a wearable multisensor device enabling continuous monitoring of vital signs and activity

This paper reports on the development and testing of a wearable device intended as a component in an ambulatory system for health monitoring of physical rehabilitation patients. The device measures heart rate, skin temperature, activity level and posture on the users chest. The wearable device has been run through a set of verification tests and the accuracy has been validated in controlled environment on 12 healthy volunteers. A long term user pilot with 5 congestive heart failure patients and their nurses was performed to test the whole system. The conclusion from the performed tests is that the developed wearable multisensor monitoring device is reliable, accurate, easy to use and fit for the purpose.

An Unobtrusive Wearable Device for Ambulatory Monitoring of Pulse Transit Time to Estimate Central Blood Pressure

There is a clinical need for improved ambulatory, frequent and unobtrusive monitoring of blood pressure and cardiac parameters like systolic time intervals. Truly unobtrusive wearable devices combining impedance cardiography with other sensors may be one possible solution. The IsenseU-BP+ device presented in this article measures single channel ECG, impedance cardiography and photo plethysmography at the chest. The device also measures activity and posture, as well as skin temperature. In this study, we report on the possibility to use these signals to measure pulse transit time for estimating blood pressure changes. Six subjects has been tested. Four of them showed good correlation between PTT and mean arterial pressure while two of the subjects had too low signal to noise ratio in the photoplethysmography signal for good estimation of PTT. Thus these results show that the quality of the raw data is promising for calculating a pulse transit time that shows good coherence with mean arterial pressure.

Reliability of plastic core solder balls in relation to formation of intermetallic compounds

The application of plastic core solder balls (PCSB) for the assembly of a silicon (Si) interposer die inside a ceramic package has been evaluated for a harsh application. Three different variants of assembly were compared. All variants survived the performed thermal shock cycling and centrifugation. Failures observed after thermal shock cycling indicated a reduced risk of crack formation for Ag-rich solder systems. Roughly 50% of each variant survived a performed application test. Significantly different failure modes were observed after thermal shock cycling compared to after the application test. Individual qualification tests are therefore recommended to evaluate reliability with respect to storage and application.

Protective jacket enabling decision support for workers in cold climate

The cold and harsh climate in the High North represents a threat to safety and work performance. The aim of this study was to show that sensors integrated in clothing can provide information that can improve decision support for workers in cold climate without disturbing the user. Here, a wireless demonstrator consisting of a working jacket with integrated temperature, humidity and activity sensors has been developed. Preliminary results indicate that the demonstrator can provide easy accessible information about the thermal conditions at the site of the worker and local cooling effects of extremities. The demonstrator has the ability to distinguish between activity and rest, and enables implementation of more sophisticated sensor fusion algorithms to assess work load and pre-defined activities. This information can be used in an enhanced safety perspective as an improved tool to advice outdoor work control for workers in cold climate.

Towards a wearable sensor system for continuous occupational cold stress assessment

This study investigated the usefulness of continuous sensor data for improving occupational cold stress assessment. Eleven volunteer male subjects completed a 90–120-min protocol in cold environments, consisting of rest, moderate and hard work. Biomedical data were measured using a smart jacket with integrated temperature, humidity and activity sensors, in addition to a custom-made sensor belt worn around the chest. Other relevant sensor data were measured using commercially available sensors. The study aimed to improve decision support for workers in cold climates, by taking advantage of the information provided by data from the rapidly growing market of wearable sensors. Important findings were that the subjective thermal sensation did not correspond to the measured absolute skin temperature and that large differences were observed in both metabolic energy production and skin temperatures under identical exposure conditions. Temperature, humidity, activity and heart rate were found to be relevant parameters for cold stress assessment, and the locations of the sensors in the prototype jacket were adequate. The study reveals the need for cold stress assessment and indicates that a generalised approached is not sufficient to assess the stress on an individual level.

Meeting end user needs in collaborative medical device technology development research projects: A qualitative case study

The aim of this case study has been to investigate to what extent user centered design (UCD) methodologies have been applied, how the process and outcomes were perceived by project team members, and what were potential barriers towards meeting end user needs. The case studied was the European Union Framework 7 integrated project d-LIVER (2011-2015), which aimed at developing an integrated care system for chronic liver disease patient management. d-LIVER is an example of a public funded, international, multidisciplinary, collaborative research project where development starts from a low technology readiness level, but where research is motivated by societal needs for better health care solutions. Awareness of central end user needs are therefore crucial. 14 project participants were interviewed. To meet societal and end user needs represent a prominent motivation factor for participants. The project organization with only clinical partners interacting with end users was accepted as a fact of life and not as a project pain point. A summary of observations and recommendations for good practice is given.

A User Study: Keyboard and Applications to Simplify Smartphone Adoption for Seniors.

The aim of the user study was to evaluate how the developed assistive physical keyboard, the Ezi-PAD, and integrated senior friendly applications, can encourage non-smartphone seniors to start using the smartphone and enable senior smartphone users to continue using a smartphone in spite of increasing motoric or visual impairment. A number of seniors with different experience and impairment, aged 64 to 86, were equipped with a smartphone and an Ezi-PAD assembly. After basic training, their use of the smartphone was monitored for up to 2 months. Five out of nine participants used the system for 2 months, and found the Ezi-PAD easy to use. The senior friendly applications gave extra utilitarian value to the phone.

Decision Support for Subjects Exposed to Heat Stress

The physiological and activity strain index (PASI) has been developed to improve the online decision support for workers exposed to heat stress. Fire fighters (smoke divers) which are exposed to both heat-stress and high-risk situations have been used as test case. PASI combines a modified version of the relatively well-known physiological strain index (PSI) with activity data from accelerometers. The algorithm has been developed based on tests in a laboratory, and it has been verified in two field tests performed by smoke divers exposed to heat stress. The verification demonstrates that it is possible to distinguish between high- and low-risk situations when data from accelerometers are added to the situation analysis. This indicates that PASI can contribute to an improved risk assessment and online decision support for smoke divers compared to using PSI alone.