| 1. |
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| 2. |
- Ahmed, Mobyen Uddin, 1976-, et al.
(författare)
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Cloud-based Data Analytics on Human Factor Measurement to Improve Safer Transport
- 2018
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Ingår i: Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering, LNICST, Volume 225. - Cham : Springer International Publishing. - 9783319762128 ; , s. 101-106
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Konferensbidrag (refereegranskat)abstract
- Improving safer transport includes individual and collective behavioural aspects and their interaction. A system that can monitor and evaluate the human cognitive and physical capacities based on human factor measurement is often beneficial to improve safety in driving condition. However, analysis and evaluation of human factor measurement i.e. Demographics, Behavioural and Physiological in real-time is challenging. This paper presents a methodology for cloud-based data analysis, categorization and metrics correlation in real-time through a H2020 project called SimuSafe. Initial implementation of this methodology shows a step-by-step approach which can handle huge amount of data with variation and verity in the cloud.
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| 3. |
- Ahmed, Mobyen Uddin, Dr, 1976-, et al.
(författare)
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Study on Human Subjects – Influence of Stress and Alcohol in Simulated Traffic Situations
- 2021
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Ingår i: Open Research Europe. - : F1000 Research Ltd. - 2732-5121. ; 1:83
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Tidskriftsartikel (refereegranskat)abstract
- This report presents a research study plan on human subjects – the influence of stress and alcohol in simulated traffic situations under an H2020 project named SIMUSAFE. This research study focuses on road-users’, i.e., car drivers, motorcyclists, bicyclists and pedestrians, behaviour in relation to retrospective studies, where interaction between the users are considered. Here, the study includes sample size, inclusion/exclusion criteria, detailed study plan, protocols, potential test scenarios and all related ethical issues. The study plan has been included in a national ethics application and received approval for implementation.
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| 4. |
- Ask, Per, 1950-, et al.
(författare)
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Bioacoustic signals from stenotic tube flow
- 1995
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Ingår i: Medical & Biological Engineering & Computing. - : Springer. - 0140-0118 .- 1741-0444. ; 33, s. 669-675
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Tidskriftsartikel (refereegranskat)
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| 5. |
- Ask, Per, et al.
(författare)
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PRESSURE MEASUREMENT TECHNIQUES IN URODYNAMIC INVESTIGATIONS
- 1990
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Ingår i: Neurourology and Urodynamics. - : Wiley. - 0733-2467 .- 1520-6777. ; 9:1, s. 1-15
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Tidskriftsartikel (refereegranskat)abstract
- It is apparent that the use of accurate pressure measurement techniques is essential for the outcome of urodynamic investigations. The aim of this paper is to estimate the demands on urodynamic pressure measurements and to review the properties of various techniques used. For the infused catheter technique, the dynamic properties are very much dependent on the complicance of the infusion system. With optimal infusion, the bandwidth and the pressure rise rate seem to be sufficient for most applications. Intraluminal microtransducers have a high bandwidth, but a certain fiber optic transducer cannot accurately measure mechanical pressure in the collapsed urethra. The principal differences in measuring hydrostatic pressure between the infused catheter technique and microtransducers should be observed. Flexion artefacts are a problem when measuring urethral pressure profiles. Newly developed transducers may offer a solution to this problem.
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| 8. |
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| 9. |
- Elwenspoek, M, et al.
(författare)
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Active joints for microrobot limbs
- 1992
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Ingår i: Journal of Micromechanics and Microengineering. - 0960-1317 .- 1361-6439. ; 2, s. 221-223
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Tidskriftsartikel (refereegranskat)
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| 10. |
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| 11. |
- Folke, Mia, et al.
(författare)
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A new capnograph based on an electro acoustic sensor
- 2008
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Ingår i: Medical and Biological Engineering and Computing. - : Springer Science and Business Media LLC. - 0140-0118 .- 1741-0444. ; 46, s. 55-59
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Tidskriftsartikel (refereegranskat)abstract
- End tidal carbon dioxide measurements with an electro acoustic capnograph prototype have been demonstrated. The aim of this study was to verify that it is possible to obtain an adequate capnogram using the prototype and to investigate the influence of ambient temperature and humidity variations. By simultaneous measurements with a reference capnograph, on subjects performing exercise, hypo- and hyperventilation, PETCO2 readings from the reference were compared with the output signal from the prototype. The capnogram from the prototype correlated well with the reference in terms of breath time. The first parts of the expiration and inspiration phases were steeper for the reference than the prototype. The output signal from the prototype correlated well with the reference PETCO2 readings with a correlation coefficient of 0.93 at varied temperature and relative humidity.
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| 12. |
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| 13. |
- Folke, Mia, et al.
(författare)
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Comparative Provocation Test of Respiratory Monitoring Methods
- 2002
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Ingår i: Journal of Clinical Monitoring and Computing. - 1387-1307. ; 17:2, s. 97-103
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Tidskriftsartikel (refereegranskat)abstract
- Objective. The aim of this study was to compare clinically relevant performance of: 1) a prototype respiratory sensor based on capnometry with two alternative signal receptor fixations, 2) a fiberoptic humidity sensor and 3) human visual observation. Comparative provocation tests were performed on volunteers at the Post-Anesthesia Care Unit at Västerås Central Hospital. Methods. The experimental tests involved 10 healthy, voluntary test subjects, instructed to intersperse normal breathing with protocol provocations of breath holding, limb and head movements, and nasal oxygen supplement. The signal outputs from the three respiratory monitoring methods were recorded on a personal computer. The signal analysis included visual categorising of the signals and counting breath events. Recognising that none of the methods could act as reference, events were classified as "unanimous," "majority" or "minority" events depending on how many of the three methods that detected a breath. Results. The average total recording time was 37 minutes per subject. The respiratory rates varied from 6.5 to 19 breaths per minute, with a mean value of 11.4 breaths/minute. The breath hold duration ranged from 18 to 50 seconds. Discrepancies between the three methods were found in more than 20% of the marked events. The most frequent majority events were due to events not recorded by the observer who, on the other hand, contributed the least to minority events. The provocations made by the subjects during the measurement did not increase the rates of majority and minority events, compared to periods of no provocation. The fiberoptic device exhibited a large count of minority events but a smaller contribution to majority events than the capnometry prototype. Conclusions. The capnometry and fiberoptic sensors exhibit differences in responses that may be understood from basic principles. The importance of the physical application of the sensor to the patient was clearly observed. The optimum design remains to be found.
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| 14. |
- Folke, Mia, et al.
(författare)
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Critical review of non-invasive respiratory monitoring in medical care
- 2003
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Ingår i: Medical & Biological Engineering & Computing. ; 41:4, s. 377-383
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Tidskriftsartikel (refereegranskat)abstract
- Respiratory failure can be difficult to predict. It can develop into a life-threatening condition in just a few minutes, or it can build up more slowly. Thus continuous monitoring of respiratory activity should be mandatory in clinical, high-risk situations, and appropriate monitoring equipment could be life-saving. The review considers non-invasive methods and devices claimed to provide information about respiratory rate or depth, or gas exchange. Methods are categorised into those responding to movement, volume and tissue composition detection; air flow, and blood gas concentration. The merits and limitations of the methods and devices are analysed, considering information. content and their ability to minimise the rate of false alarms and false non-alarms. It is concluded that the field of non-invasive respiratory monitoring is still in an exploratory phase, with numerous reports on specific device solutions but less work on evaluation and adaptation to clinical requirements. Convincing evidence of the clinical usefulness of respiratory monitors is still lacking. Devices responding only to respiratory rate, and lacking information about actual gas exchange, will have limited clinical value. Furthermore, enhancement in specificity and sensitivity to avoid false alarms and non-alarms will be necessary to meet clinical requirements. Miniature CO2 sensors are identified as one route towards substantial improvement.
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| 15. |
- Folke, Mia, et al.
(författare)
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End tidal carbon dioxide measurement using an electro acoustic sensor
- 2004
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Ingår i: Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings. - 0780384393 ; , s. 3452-3455
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- End tidal carbon dioxide measurement with an electro-acoustic sensor is demonstrated. The sensor consists of an acoustic resonator coupled to a low cost electro-acoustic element. By simultaneous measurements with a reference sensor, the new device was tested on subjects performing exercise, hypo- and hyperventilation whereby the CO2 concentration ranged from 2.1 to 7.0 kPa. The output from the experimental device correlated well with the reference CO2 readings with a correlation coefficient of 0.976. Response time for expiration less than 0.8 seconds was noted. The new device could be useful in situations where selectivity to other gases is not important.
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| 16. |
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| 17. |
- Granstedt, Fredrik, et al.
(författare)
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Gas sensor with electroacoustically coupled resonator
- 2001
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Ingår i: Sensors and Actuators. - 0925-4005. ; 78, s. 161-165
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Tidskriftsartikel (refereegranskat)abstract
- A new configuration for a gas sensor is demonstrated. The configuration consists of an electroacoustic element coupled to an acoustic resonator, such as Kundt's tube, exhibiting a resonance frequency that is related to the velocity of sound, which, in turn is a function of the molecular mass of the gas within the resonator. Electrical impedance measurements were performed, whereby a resonance peak attributable to the resonator was identified. Contributing effects to the quality factor, Q, of the resonance, was analyzed. Predictable shifts of the resonance frequency were observed when adding CO2 and He to air, and when varying the resonator length. Linearity within the experimental accuracy was confirmed. The new sensor configuration offers the potential advantages of smaller size, improved dynamic response, and lower cost. © 2001 Elsevier Science B.V. All rights reserved.
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| 18. |
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| 19. |
- Hult, Peter, 1964-
(författare)
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Bioacoustic principles used in monitoring and diagnostic applications
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The idea behind this work is linked to the experience gained from the long use of the stethoscope, and to the fact that sound originating from the body is a mechanical fingerprint, reflecting the human body functions.The aims of this thesis have been to develop bioacoustic systems using modern medical signal processing in three applications. The first was to develop a method for monitor the respiration, the second was to develop a detection method for the third heart sound and, the third was to study a swallowing detection technique and look into the potential of bioacoustic development in this area.Respiratory monitoring is of vital importance in several clinical situations. A bioacoustic signal analysis approach has been developed for monitoring of respiration. This approach includes strategies to differentiate between inspiration and expiration. In two different patient groups, the method has managed to detect 98% of the respiratory cycles.The third heart sound has been found to be related to heart failure. A tailored wavelet technique has been developed fur detection of the third heart sound. The method has been used in children and in patients with heart failure. The wavelet metod detected 87% of the third heart sounds and only 2% were classified as false positive.An investigation of an existing method for swallowing detection, computerized laryngeal analyser (CLA), was performed toghether with a pilot study involving swallowing sounds for the detection. The CLA technique was found to be inadequate for swallowing detection. The bioacoustic approach showed promise for detection of swallows.We expect in the future that bioacoustics will be an important medical field, for diagnosis, monitoring, rehabilitation and education. The methods show potential for increased use, both in hospital and primary care.
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| 20. |
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| 21. |
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| 22. |
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| 23. |
- Hök, Bertil
(författare)
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Are great innovations driven by utopian ideas?
- 2018
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Ingår i: Journal of Innovation Management. - : Universidade do Porto - Faculdade de Engenharia. - 2183-0606. ; 6:4, s. 98-116
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Tidskriftsartikel (refereegranskat)abstract
- Case studies of well documented, great innovations were performed with focus on their underlying, basic ideas. In retrospect, these ideas may seem obvious, but at the time of conception, they were considered utopian, here defined as imaginative, unexpected, counterintuitive, or unrealistic by most people, including experts. The build-up of the utopian ideas in each of the case studies is shortly described along with a critical analysis about their roles, importance, and risk exposure in the individual cases. The ideas were ranked according to defined criteria of importance, risk, and utopian potential, and this ranking was compared to the ranking of the overall impact of the analyzed innovations. The results suggest that the utopian idea potential correlates with the overall impact. The World Wide Web and the smartphones are prominent examples of great innovations driven by utopian ideas. The significance of these findings is discussed in view of current innovation models and in recognition of the heuristic character of the reported investigation.
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| 24. |
- Hök, Bertil, et al.
(författare)
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Breath Analyzer for Alcolocks and Screening Devices
- 2010
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Ingår i: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 10, s. 10-15
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Tidskriftsartikel (refereegranskat)abstract
- Alcolocks and alcohol screening devices are becoming commonplace, and their use is expected to grow rapidly with cost reduction and improved usability. A new breath analyzer prototype is demonstrated, with the prospects of eliminating the mouthpiece, reducing expiration time and volume, improving long-term stability, and reducing life cycle cost. Simultaneous CO2 measurements compensate for the sample dilution and unsaturated expiration. Infrared transmission spectroscopy is used for both the alcohol and CO2 measurement, yet the entire system is contained within a small handheld unit. Experimental results are reported on the device sensitivity, linearity, resolution, and influence from varying measuring distance. The correlation between early and full-time sampling was established in 60 subjects. Basic concept verification was obtained, whereas resolution and selectivity still needs to be improved. Further improvements are expected by system optimization and integration.
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| 25. |
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| 26. |
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| 27. |
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| 28. |
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| 29. |
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| 30. |
- Hök, Bertil, et al.
(författare)
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Unobtrusive and Highly Accurate Breath Alcohol Analysis Enabled by Improved Methodology and Technology
- 2014
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Ingår i: Journal of Forensic Investigation. - : Avens Publishing Group. - 2330-0396. ; 2:4, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- The study objective was to evaluate a novel method and technology for unobtrusive determination of breath alcohol in relation to current industrial accuracy standards. The methodology uses carbon dioxide as a tracer gas detected by sensor technology based on infrared spectroscopy. Part one of the investigation was to analyse the performance of hand-held prototype devices and included tests of resolution, unit-to-unit variation during calibration, response to alcohol containing gas pulses created with a wet gas simulator, and cross sensitivity to other substances. In part two of the study, 30 human participants provided 1465 breath tests in both unobtrusive and obtrusive use modes. The results of both parts of the study indicate that the prototype devices exceeded present industrial accuracy requirements. The proposed methodology and technology eliminate the previous contradiction between unobtrusiveness and high accuracy.
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| 31. |
- Hök, Bertil, et al.
(författare)
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Unobtrusive breath alcohol sensing system
- 2015
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Ingår i: The 24th International Technical Conference on the Enhanced Safety of Vehicles ESV2015.
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Konferensbidrag (refereegranskat)abstract
- Although the vast majority of vehicle drivers are sober, drunk driving remains to be a major contributor to fatal accidents. Massive deployment of unobtrusive breath alcohol sensing systems could potentially save tens of thousands of lives worldwide every year by preventing drunk driving [1]. The work reported here is ultimately aiming at such a system. The technical performance of the present sensing system with respect to automotive requirements is summarized, and new results towards unobtrusive breath alcohol determination within vehicle compartments are presented. Breath alcohol concentration (BrAC) can be determined unobtrusively if (i) the sensing system provides real-time signals with adequate accuracy corresponding to the local concentrations of both alcohol and a tracer gas, e g CO2, (ii) the dilution of the breath is not excessive in relation to background concentrations, (iii) the sensor location can be seamlessly integrated into the interior of a vehicle cabin. All three of these aspects are addressed in the present paper. More than a hundred prototypes based on infrared spectroscopy were fabricated and subjected to automotive qualification tests in the full temperature range -40 … +85?C. In the majority of tests, adequate performance was noted. Measures are now being taken to fill remaining performance gaps. Test results with human subjects were positive and in accordance with expectations with respect to physiological variations. In-vehicle tests showed that for the best sensor position, passive breath samples allowed BrAC to be determined at a resolution of 2-4% of the US legal limit, providing proof-of-principle for unobtrusive testing. Nevertheless, vehicle integration remains to be the major technological challenge to the objective of deployment on a large scale of unobtrusive driver breath alcohol determination. The feasibility of unobtrusive breath alcohol determination in vehicles, and adequate performance of a sensor system based on infrared spectroscopy have been experimentally demonstrated. The alcohol sensing system may advantageously be integrated into vehicles, and may also be combined with other technologies to monitor driver impairment.
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| 32. |
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| 33. |
- Johansson, Anders, 1972-, et al.
(författare)
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Sensors for respiratory monitoring
- 2004. - 3
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Ingår i: Sensors Applications, Sensors in Medicine and Health Care. - Weinheim, Germany : WileyVCH Verlag. - 3527295569 ; , s. 161-186
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 34. |
- Jonsson, Annika, 1978-
(författare)
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Pressure sore etiology - highlighted with optical measurements of the blood flow
- 2006
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In line with the quality awareness of good prevention of pressure sores and in treatment of those sores already developed, evaluation of antidecubitus mattresses plays an important role. However, there are shortages in the evaluations performed today, since often interface pressure is the only parameter regarded. Since ischaemia in the tissue is the primary cause of pressure sore, the focus in this thesis is on blood flow measurements in tissue exposed external loading. To study the tissue blood flow would give a better and more direct indication on the mattress effectiveness in minimizing the negative effects on the tissue viability.The results presented in this thesis reveal that the superficial blood flow in areas prone to pressure sore development, is affected by increased skin temperature and external loading of the tissue. Both the effects from pressure and shear stress have been studied.Measurements of the tissue blood flow is interesting to relate to the two theories about at which tissue layer the pressure sores start to develop. To achieved more knowledge about the pressure sore etiology and also be able to non-invasively measure the tissue blood flow for evaluations of antidecubitus mattresses an optical sensor has been developed. The sensor combines the two optical methods, laser Doppler flowmetry and photoplethysmography. With the design of the sensor, measurements of the superficial skin blood flow and the deeper blood flow, even the muscle blood flow, can be performed. Measurement depths of 2 mm, 8 mm, and 20 mm into the tissue is assumed.Preliminary result from measurements performed with the optical sensor in four test subjects, revealed great individual differences in blood flow, but also different response to the same external loading at different measurement depths, in the same individual. This new optical sensor is likely to be of great value in future studies of pressure sore etiology and in future evaluations of antidecubitus mattresses.
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| 35. |
- Jönsson, Mats, 1971-
(författare)
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Microfluidic Devices for Manipulation and Detection of Beads and Biomolecules
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis summarises work towards a Lab-on-Chip (LOC). The request for faster and more efficient chemical and biological analysis is the motivation behind the development of the LOC-concept. Microfluidic devices tend to become increasingly complex in order to include, e.g. sample delivery, manipulation, and detection, in one chip. The urge for smart and simple design of robust and low-cost microdevices is addressed and discussed. Design, fabrication and characterization of such microdevices have been demonstrated using low-cost polymer and glass microfabrication methods. The manufacturing is feasible, to a large extent, to perform outside the clean-room, and has subsequently been the chosen technique for most of the work. Issues of bonding reliability are solved by using polymer adhesive tapes. A planar electrocapture device with LOC-compatibility is demonstrated where beads are immobilised and released in a flowing stream. Retention of nanoparticles by means of electric field-flow fractionation using transparent indium tin oxide electrodes is presented. Moreover, a cast PDMS 4-way crossing is enabling a combination of liquid chromatography and capillary electrophoresis to enhance separation efficiency. Sample transport issues and a new flow-cell design in a quartz crystal microbalance bioanalyzer are also investigated. Fast bacteria counting by impedance measurements, much requested by the pharmaceutical industry for biomass monitoring, is carried out successfully. In conclusion, knowledge in micro system technology to build microdevices have been utilised to manipulate and characterise beads and cells, taking one step further towards viable Lab-on-Chip instruments.
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| 36. |
- Kaisdotter Andersson, Annika, et al.
(författare)
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Assessment of the breath alcohol concentration in emergency care patients with different level of consciousness
- 2015
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Ingår i: Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine. - : Springer Science and Business Media LLC. - 1757-7241. ; 23:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundMany patients seeking emergency care are under the influence of alcohol, which in many cases implies a differential diagnostic problem. For this reason early objective alcohol screening is of importance not to falsely assign the medical condition to intake of alcohol and thus secure a correct medical assessment.ObjectiveAt two emergency departments, demonstrate the feasibility of accurate breath alcohol testing in emergency patients with different levels of cooperation.MethodAssessment of the correlation and ratio between the venous blood alcohol concentration (BAC) and the breath alcohol concentration (BrAC) measured in adult emergency care patients. The BrAC was measured with a breathalyzer prototype based on infrared spectroscopy, which uses the partial pressure of carbon dioxide (pCO2) in the exhaled air as a quality indicator.ResultEighty-eight patients enrolled (mean 45 years, 53 men, 35 women) performed 201 breath tests in total. For 51% of the patients intoxication from alcohol or tablets was considered to be the main reason for seeking medical care. Twenty-seven percent of the patients were found to have a BAC of <0.04 mg/g. With use of a common conversion factor of 2100:1 between BAC and BrAC an increased agreement with BAC was found when the level of pCO2 was used to estimate the end-expiratory BrAC (underestimation of 6%, r = 0.94), as compared to the BrAC measured in the expired breath (underestimation of 26%, r = 0.94). Performance of a forced or a non-forced expiration was not found to have a significant effect (p = 0.09) on the bias between the BAC and the BrAC estimated with use of the level of CO2. A variation corresponding to a BAC of 0.3 mg/g was found between two sequential breath tests, which is not considered to be of clinical significance.ConclusionWith use of the expired pCO2 as a quality marker the BrAC can be reliably assessed in emergency care patients regardless of their cooperation, and type and length of the expiration.
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| 37. |
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| 38. |
- Kaisdotter Andersson, Annika, et al.
(författare)
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Improved breath alcohol analysis in patients with depressed consciousness
- 2010
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Ingår i: Medical and Biological Engineering and Computing. - : Springer. - 0140-0118 .- 1741-0444. ; 48:11, s. 1099-1105
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Tidskriftsartikel (refereegranskat)abstract
- Many patients in pre-hospital and emergency care are under the influence of alcohol. In addition, some of the more common pathological conditions can introduce a behaviour that can be mistaken to be related to alcohol inebriation. Fast quantitative determination of the breath alcohol concentration (BrAC) in emergency patients facilitates triage and medical assessment, but shallow expirations performed by non-cooperative patients reduce the measurement reliability. The aim of this study was to evaluate if breath alcohol analysis in non-cooperative patients can be improved with use of simultaneous measurement of the expired carbon dioxide (CO2). With prototypes of a handheld breath alcohol analyser based on infrared transmission spectroscopy the alcohol and CO2 concentration in expired breath from 37 cooperative and non-cooperative patients were measured. The results show that enhanced breath sampling with use of a pump and estimation of the end expiratory BrAC with use of the ratio between the measured partial pressure of CO2 ($$ P_{{{\text{CO}}_{2} }} $$) and a reference value of the alveolar $$ P_{{{\text{CO}}_{2} }} $$, provided adequate correlation with the blood alcohol concentration (BAC). This pre-clinical study has shown that breath alcohol analysis in shallow expirations from non-cooperative patients can be improved with use of CO2 as a tracer gas.
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| 39. |
- Kaisdotter Andersson, Annika, 1978-
(författare)
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Improved breath alcohol analysis with use of carbon dioxide as the tracer gas
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- State-of-the-art breath analysers require a prolonged expiration into a mouthpiece to obtain the accuracy required for evidential testing and screening of the alcohol concentration. This requirement is unsuitable for breath analysers used as alcolock owing to their frequent use and the fact that the majority of users are sober drivers; as well as for breath testing in uncooperative persons. This thesis presents a method by which breath alcohol analysis can be improved, using carbon dioxide (CO2) as the tracer gas, offering quality control of the breath sample, enabling the mouthpiece to be eliminated, and bringing about a significant reduction in the time and effort required for a breath alcohol screening test. With simultaneous measurement of the ethanol and the CO2 concentrations in the expired breath, the end-expiratory breath alcohol concentration (BrAC) can be estimated from an early measurement, without risk of underestimation. Comparison of CO2 and water (H2O) as possible tracer gases has shown that the larger intra- and inter-individual variations in the (end-expiratory) concentration is a drawback for CO2 whereas the advantages are a low risk of underestimation of the BrAC, and the limited influence from ambient conditions on the measured CO2 concentration. The latter is considered to be of importance because the applications likely imply that the breath tests will be conducted in an uncontrolled environment, e.g., in a vehicle or ambulance. In emergency care, the measurement of the expired CO2 concentration also provides the physicians with information about the patient's respiratory function. My hope and belief, is that with a more simple, reliable and, user-friendly test procedure, enabled with the simultaneous measurement of the CO2 in the breath sample, the screening for breath alcohol will increase. An increased number of breath alcohol analysers installed as alcolocks and more breath alcohol tests conducted in emergency care, is likely to save lives and diminish the number and severity of injuries.
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| 40. |
- Kaisdotter Andersson, Annika, 1978-, et al.
(författare)
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Influence from breathing pattern on alcohol and tracer gas expirograms : Implications for alcolock use
- 2011
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Ingår i: Forensic Science International. - Elsevier : Elsevier BV. - 0379-0738 .- 1872-6283. ; 206:1-3, s. 52-57
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Tidskriftsartikel (refereegranskat)abstract
- Measurement of breath alcohol concentration is strongly influenced by timing and the breathing pattern. In particular, shallow expiration and hyperventilation leads to underestimation of the breath alcohol concentration. In the present study, expirograms of alcohol, water and carbon dioxide were recorded in 30 healthy individuals at various breathing manoeuvres (tidal volume, slow maximum and vital capacity expiration, breath holding, and hyperventilation). Estimation of the end expiratory alcohol concentration with the use of simultaneously measured carbon dioxide was shown to reverse the tendency of underestimation at shallow expiration and hyperventilation. These findings indicate that breath alcohol estimations can be performed at shorter expiration time and reduced expired volume compared to existing alcolocks. This is believed to improve their usability and to prevent a possible route for manipulation.
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| 41. |
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| 42. |
- Kaisdotter Andersson (Jonsson), Annika, et al.
(författare)
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Development of a breath alcohol analyzer for use on patients in emergency care
- 2009
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Ingår i: IFMBE Proceedings, vol. 25, no. 1. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 9783642038907 ; , s. 84-87
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Konferensbidrag (refereegranskat)abstract
- The quantification of breath alcohol concentration is considered important input in medical diagnosis and triage at emergency medical care. In many severe emergency cases, for example head injuries, stroke, heart attack, diabetes, or psychological illness, the medical condition of the patient can be mistaken for alcohol intoxication. In cases like these, quantification of the alcohol concentration would facilitate and speed up the diagnostic procedure. However, the use of breath analyzers in medical care is limited as the state-of-the-art devices require active involvement of the patient, and expiratory volume and flow incompatible with patients respiratory function. This paper presents a prototype of a handheld breath analyzer based on infrared spectroscopy which does not require active involvement from the patient and also provides direct feedback on the quality of the breath test by measurement of the expired PCO2.
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| 43. |
- Kaisdotter Andersson (Jonsson), Annika, et al.
(författare)
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Methodology investigation of expirograms for enabling contact free breath alcohol analysis
- 2009
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Ingår i: Journal of Breath Research. - : IOP Publishing. - 1752-7155 .- 1752-7163. ; 3:3, s. 036002-
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Tidskriftsartikel (refereegranskat)abstract
- The present techniques for breath alcohol determination have usability limitations concerning practical use and the time and effort required for the test person. The rationale of the physiological assumptions in a recently demonstrated technique for breath analysis without a mouthpiece is investigated in this paper. Expirograms quantifying ethanol, carbon dioxide (CO2) and water (H2O) from 30 test subjects were analysed, with respect to the influence of individual variations in end-expiratory CO2 and H2O concentrations, and possible benefits from simultaneous measurement of CO2 or H2O. Both healthy subjects and patients suffering from pulmonary diseases performed breath tests with small and maximum volume expiration. The breath tests were recorded basically with a standard evidential instrument using infrared absorption spectroscopy, and equipped with a mouthpiece. Average concentrations were significantly higher for the maximum than for the small expirations. For the maximum expirations, the healthy subjects had a significantly higher end-expired PCO2 of 4.4 ± 0.5 kPa (mean ± standard deviation) than the patients (3.9 ± 0.7 kPa). The corresponding values for H2O were 39 ± 1 and 38 ± 1 mg l−1. The results indicate that the CO2 variability is consistent with the requirements of accuracy for alcohol ignition interlocks. In addition, CO2 as tracer gas is preferable to H2O due to its low concentration in ambient air. In instruments for evidential purposes H2O may be required as tracer gas for increased accuracy. Furthermore, the study provides support for early determination of breath alcohol concentration, indicating that determination after 2 s will introduce an additional random error of 0.02 mg l−1 or less.
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| 44. |
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| 45. |
- Ljungblad, Jonas, 1984-, et al.
(författare)
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Critical Performance of a New Breath Alcohol Analyzer for Screening Applications
- 2014
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Ingår i: Intelligent Sensors, Sensor Networks and Information Processing (ISSNIP), 2014 IEEE Ninth International Conference on. - 9781479928422 ; , s. 1-4
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Konferensbidrag (refereegranskat)abstract
- In screening applications there is a need forimproved breath alcohol analyzers. Accuracy, specificity,usability, and through-put are critical to the device performance. Objective: To characterize the critical performance of a newcontactless breath alcohol analyzer. Methods: The device ischaracterized by measurements using artificial breath gas andhuman subjects. Breath sampling is performed in ambient airusing carbon dioxide as a biomarker. Results: Resolution andinter-individual variation, response time, and specificity wereshown to meet the requirements of industrial standards. Thefeasibility of contactless measurement was demonstrated. Conclusions: The new device exhibits sufficient performance inmoderately diluted breath samples. Further work is underway toreach the objective of unobtrusive breath alcohol analysis.
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| 46. |
- Ljungblad, Jonas, 1984-, et al.
(författare)
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Development and Evaluation of Algorithms for Breath Alcohol Screening
- 2016
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Ingår i: Sensors. - : MDPI AG. - 1424-8220. ; 16:4
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Tidskriftsartikel (refereegranskat)abstract
- Breath alcohol screening is important for traffic safety, access control and other areas of health promotion. A family of sensor devices useful for these purposes is being developed and evaluated. This paper is focusing on algorithms for the determination of breath alcohol concentration in diluted breath samples using carbon dioxide to compensate for the dilution. The examined algorithms make use of signal averaging, weighting and personalization to reduce estimation errors. Evaluation has been performed by using data from a previously conducted human study. It is concluded that these features in combination will significantly reduce the random error compared to the signal averaging algorithm taken alone.
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| 47. |
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| 48. |
- Ljungblad, Jonas, et al.
(författare)
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Passive in-vehicle driver breath alcohol detection using advanced sensor signal acquisition and fusion
- 2017
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Ingår i: Traffic Injury Prevention. - : Informa UK Limited. - 1538-9588 .- 1538-957X. ; 18, s. S31-S36
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The research objective of the present investigation is to demonstrate the present status of passive in-vehicle driver breath alcohol detection and highlight the necessary conditions for large-scale implementation of such a system. Completely passive detection has remained a challenge mainly because of the requirements on signal resolution combined with the constraints of vehicle integration. The work is part of the Driver Alcohol Detection System for Safety (DADSS) program aiming at massive deployment of alcohol sensing systems that could potentially save thousands of American lives annually.Method: The work reported here builds on earlier investigations, in which it has been shown that detection of alcohol vapor in the proximity of a human subject may be traced to that subject by means of simultaneous recording of carbon dioxide (CO2) at the same location. Sensors based on infrared spectroscopy were developed to detect and quantify low concentrations of alcohol and CO2. In the present investigation, alcohol and CO2 were recorded at various locations in a vehicle cabin while human subjects were performing normal in-step procedures and driving preparations. A video camera directed to the driver position was recording images of the driver's upper body parts, including the face, and the images were analyzed with respect to features of significance to the breathing behavior and breath detection, such as mouth opening and head direction.Results: Improvement of the sensor system with respect to signal resolution including algorithm and software development, and fusion of the sensor and camera signals was successfully implemented and tested before starting the human study. In addition, experimental tests and simulations were performed with the purpose of connecting human subject data with repeatable experimental conditions. The results include occurrence statistics of detected breaths by signal peaks of CO2 and alcohol. From the statistical data, the accuracy of breath alcohol estimation and timing related to initial driver routines (door opening, taking a seat, door closure, buckling up, etc.) can be estimated.The investigation confirmed the feasibility of passive driver breath alcohol detection using our present system. Trade-offs between timing and sensor signal resolution requirements will become critical. Further improvement of sensor resolution and system ruggedness is required before the results can be industrialized.Conclusions: It is concluded that a further important step toward completely passive detection of driver breath alcohol has been taken. If required, the sniffer function with alcohol detection capability can be combined with a subsequent highly accurate breath test to confirm the driver's legal status using the same sensor device. The study is relevant to crash avoidance, in particular driver monitoring systems and driver-vehicle interface design.
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| 49. |
- Lönnblad, Jens, et al.
(författare)
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Artefacts in continuous ECG recordings : provoking and preventing manoeuvres
- 2005
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Ingår i: Scandinavian Cardiovascular Journal. - : Informa UK Limited. - 1401-7431 .- 1651-2006. ; 39:3, s. 167-171
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Tidskriftsartikel (refereegranskat)abstract
- Objectives. A systematic estimation of the effects of some clinically important artefact provoking and artefact-preventing manoeuvres.Design. A test protocol for the evaluation of technical modifications of continuous ECG recordings was tested in 17 patients. The programme comprised ECG recordings during five artefact-provoking manoeuvres (slight shaking of the ECG cables, rotating shoulders, slight electrode touching, washing, teeth-brushing) and two simple artefact-preventing manoeuvres (taping ECG cables and covering electrodes with paper cups). Results. The artefact-provoking manoeuvres induced a substantial increase in artefactual ECG. The artefact-preventing manoeuvres only incompletely prevented this increase. Conclusion. There is a great need of technical improvements to reduce the distortion of ECG by artefacts. The test protocol developed by us exposes a broad spectrum of different categories of ECG qualities and is therefore suitable for evaluating technical improvements concerning artefactual ECG.
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| 50. |
- Rahman, Hamidur, et al.
(författare)
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A Case-Based Classification for Drivers’ Alcohol Detection Using Physiological Signals
- 2016
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Konferensbidrag (refereegranskat)abstract
- This paper presents a case-based classification system for alcohol detection using physiological parameters. Here, four physiological parameters e.g. Heart Rate Variability (HRV), Respiration Rate (RR), Finger Temperature (FT), and Skin Conductance (SC) are used in a Case-based reasoning (CBR) system to detect alcoholic state. In this study, the participants are classified into two groups as drunk or sober. The experimental work shows that using the CBR classification approach the obtained accuracy for individual physiological parameters e.g., HRV is 85%, RR is 81%, FT is 95% and SC is 86%. On the other hand, the achieved accuracy is 88% while combining the four parameters i.e., HRV, RR, FT and SC using the CBR system. So, the evaluation illustrates that the CBR system based on physiological sensor signal can classify alcohol state accurately when a person is under influence of at least 0.2 g/l of alcohol.
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