| 1. |
- Seoane Martinez, Fernando, et al.
(författare)
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Method and apparatus for brain damage detection
- 2011
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Patent (populärvet., debatt m.m.)abstract
- The present invention comprises method and apparatus for detecting injury resulting in pathological processes affecting tissue within a portion of the body in a mammal, particularly a human brain. Said method comprises the steps of applying a first and a second pair of electrodes around the periphery of the portion, generating an alternating current at a known current level and applying said current between the first pair of electrodes, detecting and measuring the alternating voltage developed between the second pair of electrodes, and calculating the impedance of said portion. Further, the alternating current is applied between the first pair of electrodes in a series of increasing frequencies ranging within a known spectrum, and the resistance and the reactance for each frequency are detected and plotted against said frequency. The electrical impedance of said portion is calculated for each frequency and plotted into an impedance plot. Said resistance-reactance-and impedance-plots are finally analyzed, and any notable changes compared to normal spectrum profiles and plots are detected and evaluated.
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| 2. |
- Abtahi, Farhad, et al.
(författare)
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Electrical bioimpedance spectroscopy in time-variant systems : Is undersampling always a problem?
- 2014
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Ingår i: Journal of Electrical Bioimpedance. - : Walter de Gruyter GmbH. - 1891-5469. ; 5:1, s. 28-33
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Tidskriftsartikel (refereegranskat)abstract
- During the last decades, Electrical Bioimpedance Spectroscopy (EBIS) has been applied mainly by using the frequency-sweep technique, across a range of many different applications. Traditionally, the tissue under study is considered to be time-invariant and dynamic changes of tissue activity are ignored by treating the changes as a noise source. A new trend in EBIS is simultaneous electrical stimulation with several frequencies, through the application of a multi-sine, rectangular or other waveform. This method can provide measurements fast enough to sample dynamic changes of different tissues, such as cardiac muscle. This high sampling rate comes at a price of reduction in SNR and the increase in complexity of devices. Although the frequency-sweep technique is often inadequate for monitoring the dynamic changes in a variant system, it can be used successfully in applications focused on the time-invariant or slowly-variant part of a system. However, in order to successfully use frequency-sweep EBIS for monitoring time-variant systems, it is paramount to consider the effects of aliasing and especially the folding of higher frequencies, on the desired frequency e.g. DC level. This paper discusses sub-Nyquist sampling of thoracic EBIS measurements and its application in the case of monitoring pulmonary oedema. It is concluded that by considering aliasing, and with proper implementation of smoothing filters, as well as by using random sampling, frequency-sweep EBIS can be used for assessing time-invariant or slowly-variant properties of time-variant biological systems, even in the presence of aliasing. In general, undersampling is not always a problem, but does always require proper consideration.
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| 3. |
- Buendia, Ruben, 1982, et al.
(författare)
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Estimation of body fluids with bioimpedance spectroscopy: state of the art methods and proposal of novel methods
- 2015
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Ingår i: Physiological Measurement. - : IOP Publishing. - 0967-3334 .- 1361-6579. ; 36:10
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Tidskriftsartikel (refereegranskat)abstract
- Determination of body fluids is a useful common practice in determination of disease mechanisms and treatments. Bioimpedance spectroscopy (BIS) methods are non-invasive, inexpensive and rapid alternatives to reference methods such as tracer dilution. However, they are indirect and their robustness and validity are unclear. In this article, state of the art methods are reviewed, their drawbacks identified and new methods are proposed. All methods were tested on a clinical database of patients receiving growth hormone replacement therapy. Results indicated that most BIS methods are similarly accurate (e.g. < 0.5 +/- 3.0% mean percentage difference for total body water) for estimation of body fluids. A new model for calculation is proposed that performs equally well for all fluid compartments (total body water, extra-and intracellular water). It is suggested that the main source of error in extracellular water estimation is due to anisotropy, in total body water estimation to the uncertainty associated with intracellular resistivity and in determination of intracellular water a combination of both.
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| 4. |
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| 5. |
- Ferreira Gonzalez, Javier, 1982-
(författare)
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Textile-enabled Bioimpedance Instrumentation for Personalised Health Monitoring Applications
- 2013
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A growing number of factors, including the costs, technological advancements, an ageing population, and medical errors are leading industrialised countries to invest in research on alternative solutions to improving their health care systems and increasing patients’ life quality. Personal Health System (PHS) solutions envision the use of information and communication technologies that enable a paradigm shift from the traditional hospital-centred healthcare delivery model toward a preventive and person-centred approach. PHS offers the means to follow patient health using wearable, portable or implantable systems that offer ubiquitous, unobtrusive bio-data acquisition, allowing remote access to patient status and treatment monitoring.Electrical Bioimpedance (EBI) technology is a non-invasive, quick and relatively affordable technique that can be used for assessing and monitoring different health conditions, e.g., body composition assessments for nutrition. EBI technology combined with state-of-the-art advances in sensor and textile technology are fostering the implementation of wearable bioimpedance monitors that use functional garments for the implementation of personalised healthcare applications.This research studies the development of a portable EBI spectrometer that can use dry textile electrodes for the assessment of body composition for the purposes of clinical uses. The portable bioimpedance monitor has been developed using the latest advances in system-on-chip technology for bioimpedance spectroscopy instrumentation. The obtained portable spectrometer has been validated against commercial spectrometer that performs total body composition assessment using functional textrode garments.The development of a portable Bioimpedance spectrometer using functional garments and dry textile electrodes for body composition assessment has been shown to be a feasible option. The availability of such measurement systems bring closer the real implementation of personalised healthcare systems.
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| 6. |
- Ferreira, Javier, 1982-, et al.
(författare)
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A handheld and textile-enabled bioimpedance system for ubiquitous body composition analysis. : An initial functional validation
- 2016
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Ingår i: IEEE journal of biomedical and health informatics. - : Institute of Electrical and Electronics Engineers (IEEE). - 2168-2194 .- 2168-2208. ; 21:5
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, many efforts have been made to promote a healthcare paradigm shift from the traditional reactive hospital-centered healthcare approach towards a proactive, patient-oriented and self-managed approach that could improve service quality and help reduce costs while contributing to sustainability. Managing and caring for patients with chronic diseases accounts over 75% of healthcare costs in developed countries. One of the most resource demanding diseases is chronic kidney disease (CKD), which often leads to a gradual and irreparable loss of renal function, with up to 12% of the population showing signs of different stages of this disease. Peritoneal dialysis and home haemodialysis are life-saving home-based renal replacement treatments that, compared to conventional in-center hemodialysis, provide similar long-term patient survival, less restrictions of life-style, such as a more flexible diet, and better flexibility in terms of treatment options and locations. Bioimpedance has been largely used clinically for decades in nutrition for assessing body fluid distributions. Moreover, bioimpedance methods are used to assess the overhydratation state of CKD patients, allowing clinicians to estimate the amount of fluid that should be removed by ultrafiltration. In this work, the initial validation of a handheld bioimpedance system for the assessment of body fluid status that could be used to assist the patient in home-based CKD treatments is presented. The body fluid monitoring system comprises a custom-made handheld tetrapolar bioimpedance spectrometer and a textile-based electrode garment for total body fluid assessment. The system performance was evaluated against the same measurements acquired using a commercial bioimpedance spectrometer for medical use on several voluntary subjects. The analysis of the measurement results and the comparison of the fluid estimations indicated that both devices are equivalent from a measurement performance perspective, allowing for its use on ubiquitous e-healthcare dialysis solutions.
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| 7. |
- Flisberg, Anders, 1958, et al.
(författare)
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Does indomethacin for closure of patent ductus arteriosus affect cerebral function?
- 2010
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Ingår i: Acta Paediatrica. - : Wiley. - 0803-5253 .- 1651-2227. ; 99:10, s. 1493-1497
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To study whether indomethacin used in conventional dose for closure of patent ductus arteriosus affects cerebral function measured by Electroencephalograms (EEG) evaluated by quantitative measures. Study design: Seven premature neonates with haemodynamically significant persistent ductus arteriosus were recruited. EEG were recorded before, during and after an intravenous infusion of 0.2 mg/kg indomethacin over 10 min. The EEG was analysed by two methods with different degrees of complexity for the amount of low-activity periods (LAP, "suppressions") as an indicator of affection of cerebral function. Results: Neither of the two methods identified any change in the amount of LAPs in the EEG as compared to before the indomethacin infusion. Conclusion: Indomethacin in conventional dose for closure of patent ductus arteriosus does not affect cerebral function as evaluated by quantitative EEG.
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| 8. |
- Gund, Anna, 1980, et al.
(författare)
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Care@Distance – Disease Management för hjärtsviktspatienter i hemmet
- 2007
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Ingår i: Medicinteknikdagarna, 2-3 October 2007, Örebro, Sweden. - : Svensk förening för medicinsk teknik och fysik, Örebro Läns Landsting, Örebro Universitet, Stiftelsen för strategisk forskning, Vetenskapsrådet, Vinnova.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Antalet äldre i samhället ökar, och med det kostnaderna p.g.a. kroniska åldersrelaterade sjukdomstillstånd. Ett sådant tillstånd är hjärtsvikt vilket drabbar ca 2 % av västvärldens befolkning. Forskning har visat att IT-baserad hemvård för s.k. Disease Management kan resultera i minskade kostnader så väl som ökad livskvalitet hos patienterna. Inom projektet Care@Distance är avsikten att utforma ett sådant system där tyngden ligger dels på regelbundna dagliga enkla mätningar av fysiologiskt relaterade parametrar såsom vikt och blodtryck, och dels på formulär där patienten svarar på några enkla frågor om det upplevda tillståndet. Syftet är att få med både objektiv och subjektiv information som sedan kan ligga till grund för en förbättrad vård av den enskilde patienten. Systemet utformas främst för att skapa underlag för en bättre långsiktig behandling, terapi och för uppföljning av Treatment Compliance, men även för att hantera akuta situationer genom t.ex. larm till vårdgivaren. Under projektets tid har ett samarbete med DAGA-kliniken på Östra sjukhuset upprättats, genom bl.a. diskussioner om frågeformulärets utformning. Under våren 2007 har även två förstudier genomförts på kliniken, den första med inriktning mot patientdelen av systemet, och den andra mot vårdgivarsidan. Studien visar att patientdelen är lätthanterad ur patientsynpunkt samt att intresse för systemet finns. Även på vårdgivarsidan är resultaten positiva när det gäller design, funktioner och intresse, men utrymme för förbättringar finns. Fortsatta studier i form av ett längre försök i hemmet hos patienter är planerat under sommaren och hösten 2007. Under sommaren kommer även patientdelen att vidareutvecklas med ny programvara. Ett framtida projekt innefattar att utveckla en metod för att utnyttja EBI (Elektrisk Bio-Impedans). Med relativt enkla och robusta mätningar förväntas mycket användbar och relevant information om sjukdomstillståndet kunna erhållas med denna metod, men detta kräver att ny sensorteknik utvecklas för hemmiljön.
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| 9. |
- Gund, Anna, 1980, et al.
(författare)
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Care@Distance - Home Monitoring System for CHF Patients
- 2007
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Ingår i: Tromsø Telemedicine and eHealth Conference, 11-13 June, 2007, Tromsø, Norway.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The number of elderly people in the society is increasing, and with that the expected the health care costs. One reason for this is that the probability of contracting a chronic illness increases with age. Congestive heart failure (CHF) is a typical such illness and it affects approximately 2 % of the population in the western world. Most of the patients are over 60 years of age. By using IT-based home care solutions for follow-up, disease management and treatment compliance these costs can potentially be reduced at the same time as the care of the patient can be improved. It is a matter of patient quality as well as reduced costs. Many CHF patients tend to return to hospitals with acute conditions where they are admitted for care, only to be discharged a couple of days later. This results in considerable costs for the health care sector, and suffering and insecurity for the patient. Studies have shown that using tele-care, or eHealth, symptoms can be discovered earlier than with traditional care. There is also a better possibility to study and improve patient treatment compliance. Within Care@Distance the intention is to develop a system that can support in acute situations as well as in the long term disease management. Regular daily measurements of physiological data, such as body weight and blood pressure will be done, together with questionnaires where the patients describe their actual medical situation. The combined objective and subjective information can then form a foundation for improving the care of the individual patient. In this project the type of physiological data to be collected and the questionnaire have been defined in collaboration with the DAGA-clinic at Östra Hospital, and Institute of Health and Care Sciences at Sahlgrenska Academy, both situated in Gothenburg, Sweden. The system is build up of two parts. One is the home client and the other the system server consisting of a web portal for medical personnel together with a central database. The home client is currently a portable Tablet PC combined with a scale and a blood pressure monitor. The computer program is designed to assist the patient carrying out the different measurements and questionnaires. The results are initially stored on a local database in the home client. Measurements will be made of body weight and blood pressure and questions of the current health status of the patient will be asked. These surveys will typically be performed one or several times a day depending on the patient's health status. When the measurement session is over the local database is synchronized with a central database. Measured data and results are sent to the central database, and the home client checks for updates, new configurations, etc. Health care personnel access the information on the central database when needed through the web portal. Besides examining the patient's physiological data and questionnaire results the personnel can also administrate the home client i.e. define measurements, measurement intervals, questionnaire forms etc. Currently a first generation of the system is out on trial on healthy volunteers in order to verify the functionality of the system. So far the results are promising, and have also led to a number of improvements of both the home client and the web portal. The first clinical trial will begin in the spring of 2007 where a small trial group, identified by the DAGA-clinic, will participate. The focus of this trial is to establish and evaluate interdisciplinary work procedures and technical infrastructure. Following this the system will be stepwise developed regarding measurements and increased functionality. Of special interest in the future of this project is to develop and verify sensors based on the use of Electric Bio Impedance (EBI). This technique allows for a robust, cheap and relatively simple way to acquire physiological information of large clinical value in relation to CHF treatment e.g. heart function and fluid balance. The ambition is to develop and verify different designs of this kind of sensors, suitable for the home care environment, where user-friendliness is one important factor.
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| 10. |
- Gund, Anna, 1980, et al.
(författare)
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Care@Distance, Home Monitoring System for Patients with Congestive Heart Failure
- 2006
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Ingår i: Medicinteknikdagarna, 3-4 October 2006, Uppsala, Sweden.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Allt eftersom antalet äldre och långtidssjuka ökar i samhället, förväntas också kostnaderna för sjuk- och hälsovård att öka. Hjärtsvikt är en sjukdom som drabbar omkring 2 % av befolkningen i västvärden, och de flesta patienter är över 60 år. Denna sjukdom spelar därför tillsammans med ett antal andra vanliga åldersrelaterade sjukdomar en stor roll i denna ökning. Med hjälp av IT-baserad hemövervakning och behandlingsuppföljning av hjärtsviktspatienter kan vi potentiellt både minska sjukvårdskostnaderna och förbättra vården för den enskilda individen. Inom Care@Distance är avsikten att utforma ett sådant system där tyngden ligger dels på regelbundna dagliga enkla mätningar av fysiologiskt relaterade parametrar såsom t.ex. vikt, blodtryck och puls, och dels formulär där patienten själv beskriver sin situation. Syftet är att få med både objektiva och subjektiva resultat vilka sedan kan ligga till grund för en förbättrad vård av den enskilde patienten. Systemet utformas för att hantera såväl akuta situationer, t.ex. genom att larma vårdpersonal vid avvikelser utifrån uppsatta gränser, samt skapa underlag för en bättre långsiktig behandling och terapi. Sjukvårdskostnaderna förväntas härigenom reduceras i och med att sjukdomen kan behandlas bättre och färre akutsituationer uppstår. Dessutom, och minst lika viktigt, förväntas patientens livssituation förbättras. Både typen av mätdata samt frågeformulär utarbetas i samarbete med DAGA-kliniken på Östra sjukhuset i Göteborg och Vårdvetenskapliga fakulteten vid Sahlgrenska Akademien. Behandlingsmässigt innebär Care@Distance att patienten kommer att erbjudas likartade mätningar och frågor hemma som vid återbesök på kliniken. Skillnaden är att hemmet kan dessa frågor ställas, och mätningar göras, flera gånger om dagen, medan de på kliniken kanske bara görs varannan månad. Detta ger bl.a. vårdgivaren en större informationsmängd att fatta vårdrelaterade beslut på. De första fältförsöken kommer att ske i början av hösten 2006. En liten försöksgrupp på ca 3-5 personer, identifierade med hjälp av DAGA-kliniken på Östra sjukhuset, kommer att medverka initialt. Fokus i dessa första test är att etablera och utvärdera arbetssätt och teknisk infrastruktur. Generellt är systemet utformat för att vara mycket användarvänligt i alla delar. I ett nästa steg skall EBI (Elektrisk Bio-Impedans) testas för att om möjligt inkluderas i mätmodaliteterna. Med relativt enkla och robusta mätningar förväntas mycket användbar och relevant information om sjukdomstillståndet hos de aktuella patienterna kunna erhållas med denna metod.
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