Currently, the transplantation of islets of Langerhans is a viable means to maintain control of blood sugar levels and reduce the risk of hypoglycemia in defined populations with brittle type I diabetes mellitus or those requiring pancreatectomy. However, the process of islet isolation is highly variable and not all isolations result in islet numbers or quality suitable for transplantation. This thesis aimed to improve transplantation success through optimization and standardization of the isolation process and to identify pretransplant variables associated with early islet engraftment. A previously disregarded enzyme activity, tryptic-like activity (TLA), has been identified to influence pancreas digestion efficiency and islet isolation success in both the preclinical and clinical situations. For human pancreases, islet isolation success rates improved from 0% in the lowest TLA group to over 50% in the highest TLA groups without affecting islet quality. These findings should help standardize evaluation of enzymes for clinical islet isolation. A closed, automated, pump-made gradient system was compared to the open, manual method for islet separation. No differences were observed in expected gradient volumes, islet yields or total purities between the two methods. The pump-made gradient system successfully removed manual influences on density gradient production while fulfilling regulatory requirements for closed system processing. Islet quantification was evaluated with computer-assisted digital imaging analysis (DIA) and a semi-closed assessment system. By using the DIA system method, which measures islet purity and pellet volume instead of manual counting methods, variation in islet counts and purity reduced by almost half. By using a transplant outcome measurement of C-peptide adjusted by blood glucose and creatinine, we identified four pretransplant factors that affect early transplant outcome. Of the four factors, one was related to the organ transport time, one to function of the islets, and two to the transplanted tissue volume. When these four factors were put into a predictive model, it accounted for about 40% of the transplant outcome. The work contained in this thesis identifies and optimizes a number of critical elements related to islet isolation and transplantation protocols.

In inhalation anesthesia life-support systems are used to provide gases to the patient and to monitor important parameters. These systems are used in dynamic and stressful situations where the information-load on the operators often is significant. This thesis presents a design concept of an anesthetic system. The design goal has been to keep the information-load on the operator low with the objective to minimize confusion and error. A number of contextual inquiries were made in the operating room during surgery at four hospitals in Sweden. The goal was to understand the actual use-situations when anesthetic systems are employed. In addition to these inquiries a number of interviews with clinicians were made. The result from the contextual inquiries and the interviews was a set of qualities-in-use; characterizations of the preferred use-qualities of the system. Based on these qualities-in-use the actual design concept was developed. The design concept is described in terms of sketches, scenarios and the qualities-in-use on which it was based. The thesis also includes a discussion on the advantages and disadvantages of the design concept.

Europeiska unionen röstade igenom nya regelverk för medicintekniska produkter och för medicintekniska produkter för in vitrodiagnostik 2017. Regelverken implementerades 2021. De nya regelverken innebär striktare krav på tillsyn, klinisk prövning och spårbarhet, för att stärka patientsäkerheten. Målet med projektet var att undersöka om vårdcentralerna inom Stockholm läns sjukvårdsområde (SLSO) uppfyller de nya regelverken och sedan ta fram en analysmodell och analysera hur väl de anpassar sig till regelverken. För att säkerställa att SLSO:s vårdcentralerna uppfyller de nya regelverken utfördes i detta projekt fysiska inventeringar på tio slumpmässigt utvalda enheter som inte har befintliga serviceavtal med leverantörer eller servicegivare. Det visade sig att på samtliga enheter nyttjas konsumentprodukter till patienter, som inte är avsedda för medicinskt bruk. Flertalet enheter saknade även produkter som bör finnas tillgängliga. Överlag var enhetscheferna på vårdcentralerna inte insatta i de nya regelverken och visste inte att produkterna de använde inte är avsedda för sjukvård. De hade även flera produkter som var gamla och/eller trasiga som användes på daglig basis vilket inte uppfyller kraven på patientsäkerheten. Slutsatsen blev därför att SLSO:s vårdcentraler inte uppfyller de nya regelverken. / The European Union voted through new regulations regarding medical devices and medical devices for in vitro diagnostics in 2017. These new regulations were implemented in 2021. The new regulations entailed stricter supervision, clinical testing, and traceability requirements to strengthen patient safety. To ensure that care centers within Region Stockholm comply with the new regulations, physical inventories were carried out at ten randomly selected units that do not have existing service agreements with suppliers or service providers. To compare different units’ individual adaptations to the regulations, an analysis model was created in which the proportion of products that were not approved for medical use and the lack of certain necessary equipment were factors. In all units, consumer products are used for patients, which are not intended for medical use, and several units lack products that should be available. Overall, the unit managers at the care centers were unfamiliar with the new regulations and were unaware that the products they used were not intended for healthcare. The care centers also had several old and/or broken products that were used daily, which does not meet the requirements for patient safety. The conclusion was therefore that the care centers in Region Stockholm do not comply with the new regulations.

This thesis examines how the pressure sensors can be used in rehabilitation for patients with weakened hand strength. The rehabilitation process usually contains everyday tasks to evaluate the patient’s capability and the tools for this part of the rehabilitation process are few. The challenges will be to find a suitable sensor for the application and how to implement the sensor in a versatile prototype with direct feedback for the user. To solve this problem, research will be conducted on different pressure sensor types to determine the most suitable one for this implementation. The resulting prototype is utilizing a force sensing resistor (FSR) mounted on a glove together with a module that presents direct feedback to the patient and caretaker. The glove has pressure sensors in each fingertip to detect the applied force for each individual finger when the patient grips an object. To present the feedback, a visual interface is created in the form of a hand with a LED for each finger, which provides direct visual feedback and a display to present numerical data. / Denna avhandling undersöker hur trycksensorer kan användas vid rehabilitering av patienter med försvagad handstyrka. Rehabiliteringsprocessen innehåller vanligtvis vardagliga uppgifter för att utvärdera patientens förmåga och nuvarande hjälpmedel är få. Utmaningarna är att hitta en lämplig sensor för applikationen och hur man kan implementera sensorn i en mångsidig prototyp med en direkt återkoppling för användaren. För att lösa detta problem kommer forskning att genomföras på olika typer av trycksensorer. Detta görs för att kunna bestämma den mest lämpade sensortypen för denna implementering. Den resulterande prototypen består av en handske med kraft känsliga resistorer (FSR) och en separat modul som ger direkt återkoppling till patienten och vårdtagaren. Handsken har en sensor i varje fingertopp för att detektera applicerad kraft för varje enskilt finger när patienten greppar ett föremål. För att presentera data från sensorerna skapas ett visuellt gränssnitt. Gränssnittet är i form av en hand med lysdioder i varje finger för direkt återkoppling och en bildskärm för att presentera numeriska data.

En populär metod för manipulering av celler är användning av ultraljud. Då användning av ultraljud ofta medför att temperaturen i dess omgivning ändras, finns ett intresse av att karakterisera temperaturutvecklingen för ett chip monterat på en givare som sänder ut högfrekvent ultraljud. Skulle det vara möjligt att uppnå en stabil temperaturen i chipet genom att endast kontrollera spänningen som styr ultraljudet så skulle det medföra stora besparingar inom energikostnader på grund av att den nuvarande uppställningen använder sig av ett kylsystem som kräver mycket energi. Projektet gick ut på att testa hur chipets temperatur svarade på olika amplituder på den spänning som styrde ultraljudsgivaren. Detta gjordes genom att läsa av temperaturen i chipet kontinuerligt med hjälp av en IR kamera under cykler av upphettning och avsvalning. Resultatet visade på en viss linjäritet mellan spänning och temperatur i chipet inom vissa spänningsintervall. Konduktion av värmeenergi från ultraljudsgivaren verkar vara det dominerande bidraget till chipets temperaturförändring. Det har visat sig möjligt att kunna styra temperaturen med så enkla regulatorer som en proportionell regulator, men om snabbare uppvärmningstid är önskvärt, är det fullt möjligt att uppnå det med mer sofistikerade regulatorer. / A popular method for manipulation of cells is the use of ultrasound. Since the ultrasound usually affects the temperature in its surroundings, there is an interest in characterizing the temperature change in a chip mounted on a transducer that is supplying high frequency ultrasound. If it were possible to control the temperature in the chip by only controlling the voltage being supplied to the ultrasound transducer, the energy costs would be reduced due to not needing a high energy demanding cooling system to control the temperature. By varying the amplitude of the voltage being supplied to the transducer, the temperature in the chip was observed continuously. An IR camera was used to measure the temperature during cycles of heating and cooling. The result shows that there is a certain linearity between the voltage applied to the transducer and the temperature in the chip in certain intervals of voltage. Conduction of heat energy seems to be the lead reason of temperature change in the chip. It has been shown to be possible to control the temperature with a controller as simple as a proportional one, but if a faster pace of heating is desired, then the use of a more sophisticated one should suffice.

Bakgrund: Hjärtat är en stark symbol för människor. Den medicintekniska utvecklingen har förändrat människors livsvillkor och sjuksköterskans arbete. Den tekniska utvecklingen speglar ett behov personcentrerad vård. Detta har väckt ett intresse för hjärttransplantationspatienters upplevelser. Syfte: Att beskriva patienters upplevelser efter en hjärttransplantation. Metod: En litteraturöversikt genomfördes med åtta artiklar. Datainsamlingen genomfördes på databaserna CINAHL och Pubmed. Resultatet analyserade med Fribergs analysmetod. Resultat: Utifrån resultatet framträdde fyra teman: Medicinsk påverkan,sociala relationer, känslomässiga prövningar och en andra chans. Sammanfattning: Litteraturöversikten gav en inblick i hjärttransplantationspatienternas upplevelser efter transplantationen. Dessa handlade om upplevelser av medicinbiverkningar, förändringar i sociala relationer, utmaningar i känsloliv och deras upplevelser efter att ha fått en andra chans på livet. / Background: The heart is a powerful symbol for humans. The technological advancements in medicine have changed people's living conditions and the work of nurses. The technological development reflects a need for person-centered care. This has generated an interest in the experiences of heart transplantation patients. Aim: To describe patients experiences after a heart transplantation. Method: A literature review was conducted utilizing eight articles. Data collection was performed on the CINAHL and PubMed databases. The results were analyzed using Friberg's analysis method. Results: Based on the results, four themes emerged: Medical impact, social relationships, emotional trials, and a second chance. Summary: The literature review provided insight into the experiences of hearttransplant patients post-transplantation. These experiences included encountering medication side effects, changes in social relationships, emotional challenges, and reflections on their experiences after being given a second chance at life.

Bakgrund: Operationssjukvården utvecklas ständigt med nya medicintekniska produkter. Operationssjuksköterskan ansvarar för att ta fram rätt medicintekniska produkter till operationen och för att de medicintekniska produkterna ska fungera. Fungerar inte medicintekniska produkter under operationen hotar det patientsäkerheten. Syfte: Att undersöka hur operationssjuksköterskan arbetar med medicintekniska produkter på operationssalen. Metod: En strukturerad, icke-deltagande observationsstudie med kvantitativ ansats har genomförts på två olika sjukhus i västra Sverige. Totalt genomfördes 21 observationer som analyserades med beskrivande statistik. Resultat: Medelvärdet på antal medicintekniska produkter i operationssalen var nio. Operationssjuksköterskan utförde funktionstest av medicintekniska produkter innan operationens start i 76 % av observationerna. Problem med medicintekniska produkter uppstod i 71 % av observationerna, vilket ledde till att vid en tredjedel av observationerna fick någon i operationsteamet gå ut från operationssalen för att hämta nya medicintekniska produkter. Medelvärdet för tiden att hämta ny medicintekniska produkter var två minuter och 29 sekunder. Konklusion: Studien har bidragit med en överblick över hur operationssjuksköterskans arbetar med medicintekniska produkter på operationssalen, både hur operationssjuksköterskan förbereder medicintekniska produkter innan operationens start och hur många problem som uppstår med medicintekniska produkter under operationen som operationsteamet måste lösa. Att förebygga problem med medicintekniska produkter är viktigt för patientsäkerheten, operationspersonalens arbetsmiljö och produktiviteten för operationsenheten. / Background: Surgical care is constantly evolving with new medical devices. The operating room nurse is responsible for providing correct medical devices and making sure the medical devices function correctly. If the medical devices are not functioning correctly the patient safety is endangered. Aim: Examine how the operating room nurse works with medical devices in the operating room. Method: A structured, non-participating observation study with a quantitative design was conducted at two hospitals in western Sweden. A total of 21 observations were analyzed using descriptive statistics. Result: The mean number of medical devices in the operation room was nine. The operating room nurse performed function tests of the medical devices prior to operation in 76 % of observations. Problems with medical devices occurred in 71 % of observations, resulting in someone from the operating team having to leave the operating room and fetch new medical devices in one third of observations. The mean time required for fetching new medical devices was two minutes and 29 seconds. Conclusion: The study offers an overview of how the operating room nurse utilizes medical devices in the operating room, both how the operating room nurse prepare the medical devices before the start of the operation and how many problems occur with the medical devices during the operation which the operating team must resolve. Preventing problems with medical devices are important due to patient safety, work environment and productivity in the operating ward.

<p> </p><p>In orthopaedic practice, fractures are usually stabilised with metal screws or rods. This is done in order to keep the fracture parts in place during the rather slow healing process. The healing time can potentially be reduced by local- or systemic treatment with different bone promoting drugs. In later years, lithium, otherwise used to treat bipolar disease, has shown promise to be such a drug.</p><p> </p><p>The aim of this master thesis was to find a way to coat metal bone screws with lithium and to characterise the coating. The coating was to be designed in such a way that it could release lithium to the surrounding bone tissue.</p><p> </p><p>Lithium chloride was incorporated into a titanate sol-gel and attached to silicon wafers and stainless steel screws by dip coating. Wafers were used for initial <em>in vitro</em> studies of how lithium changed coating characteristics. This was studied using ellipsometry, AFM and SEM. Lithium is most probably physisorbed and not incorporated into the network building up the sol-gel. Coating structure is changed as more lithium is incorporated. For large amounts of lithium, the nanoparticles normally formed when curing the sol-gel are inhibited. One effect of this is reduced bioactivity, seen as a reduced ability for calcium phosphate crystals to nucleate on the coating when immersed in simulated body fluid.</p><p>Lithium release was investigated using AAS. Lithium is released from the coating, showing a burst effect. By changing the number of coating layers used, the release profile can be partly altered. The coating was also applied to screws, showing good attachment, and the lithium release profile was similar to the one seen from wafers.</p><p>Finally, a screw model was used in rats to assess the effect of local lithium treatment from screws and systemic lithium treatment on fracture healing. In the model, a screw was inserted in tibia, mimicking a fracture. When the bone around the screw was healed, a pullout test was performed, giving information about the strength of the bone surrounding the screw. No significant difference could be found for either local- or systemic lithium treatment compared to control. However, when evaluating the strength of intact bone in a similar way, a positive effect of systemic lithium treatment could be seen. Therefore, it is still likely that lithium has a positive effect on bone and further studies are needed to fully evaluate its role in fracture healing.</p><p> </p> / <p><p>Vid behandling av benbrott stabiliseras vanligtvis frakturen internt med metallskruvar och</p><p>metallstavar. Detta görs för att hålla brottbitarna på plats under den relativt långsamma läkprocessen. Det är möjligt att minska tiden för frakturläkning genom att lokalt eller systemiskt behandla med olika läkemedel som främjar bentillväxt. På senare år har det presenterats bevis för att litium, som annars används som psykofarmaka, fungerar som ett sådant läkemedel.</p><p> </p><p>Syftet med detta examensarbete var att hitta en metod för att fästa litium på benimplantat. Litium skulle fästas på ett sådant sätt att frisläppning till omgivande vävnad blev möjlig.</p><p> </p><p>Litiumklorid inkorporerades i en titanat-solgel och lager av detta lades på kiselytor och rostfria skruvar genom s.k. ”dip-coating”. Kiselytorna användes för initiala <em>in vitro</em>-studier av hur litium ändrade beläggningens egenskaper. Litium sitter antagligen fast på ytan av det tredimensionella nätverk som utgör solgelen, istället för att sitta inbundet i nätverket. Lagerstrukturen ändras ju mer litium som inkorporeras och vid stora mängder skapas inte de nanopartiklar som vanligtvis finns i en solgel-baserad beläggning. En följd av detta är reducerad bioaktivitet för beläggningen, dvs. en minskad förmåga för kalciumfosfatkristaller att bildas på ytan. Litium frisläpps från beläggningen, dock sker denna frisläppning snabbt. Genom att belägga ytan med flera lager av solgel kan frisläppningskinetiken delvis ändras. Solgelen kunde också med god vidhäftning appliceras på skruvar och frisläppningskinetiken från en skruv är liknande den från en kiselyta.</p>Slutligen användes en skruvmodell i råtta för att undersöka vilken effekt lokal respektive systemisk litiumbehandling har på frakturläkning. I modellen efterliknas ett benbrott genom att en skruv sätts in i skenbenet.  När benvävnaden runt skruven har läkt görs ett utdragstest på skruven vilket ger information om benets styrka. Ingen signifikant skillnad i skruvens utdragskraft kunde ses mellan de båda försöksgrupperna och kontrollgruppen. Däremot hade gruppen som fick systemisk litiumbehandling fått starkare ben totalt, vilket indikerar att litium har effekt på <em>intakt</em> ben. På grund av dessa resultat finns det fortfarande skäl att tro att litium har en positiv påverkan på ben, varför dess effekt på frakturläkning bör undersökas ytterligare. </p>

<p>Optical coherence tomography is an imaging modality with an outstanding resolution. During the project, a time domain OCT system based on a Michelson fibre interferometer was implemented and put into operation. A super-luminescent diode with a centre wavelength of 1295nm and a bandwidth of 45nm was selected as light source and a linear variable delay line as reference. Basic tests were made on phantoms constructed of filter foils and on gel-like agar slices with optical properties similar to human tissue. It was shown that the achievable resolution was at least 36um and can be increased. The system can easily be enhanced to create two-dimensional images.</p> / <p>Optische Kohärenztomographie ist ein bildgebendes Verfahren mit einer hervorragenden räumlichen Auflösung. Im Laufe des Projekts wurde ein OCT-System basierend auf einem faseroptischen Michelson-Interferometer implementiert und in Betrieb genommen. Als Lichtquelle wurde eine Superlumineszenzdiode mit einer Mittenwellenlänge von 1295nm und einer Bandbreite von 45nm gewählt. Eine variable optische Verzögerungsleitung diente als Referenz. Erste Messungen an Filterfolien und gelähnlichen Agarphantomen, die die optischen Eigenschaften von menschlichem Gewebe nachbildeten, lieferten eine räumliche Auflösung von mindestens 36um. Durch die modulare Bauweise ist das System leicht für zweidimensionale Aufnahmen erweiterbar.</p>

An increased use of medical devices has been assumed to be a major cause of rising healthcare expenditures. Nations around the world are trying to keep costs down, but strong incentives still exist for the development and use of new devices. Innovation is, however, never exclusively good or bad and it is not easy to evaluate the net effect. Theories and empirical research on innovation have been produced for more than 100 years. In this, the diffusion of innovations has attracted the most interest, while other areas, such as the integration of technologies, have been less thoroughly researched. This thesis presents a model of medical device innovation in hospitals – from the first idea and invention effort to regular use of a new technology. The suggested model is built on three fundaments: (1) academic innovation literature, (2) empirical studies, and (3) observations of on-going innovation processes. The model is a synthesis of the accumulated knowledge in different innovation research traditions, and of empirical studies of the Swedish healthcare system and the medical device industry. The aim is to give a comprehensive picture of the innovation process, and to provide a theoretical model, which can be used for studying and influencing the paths of medical device innovations into healthcare practice. In order to achieve a balanced rate of change, with long-term societal benefits, an inter-disciplinary approach is necessary in the planning and regulation of medical device innovation. The new model combines academic views with political/entrepreneurial and healthcare views. Innovation, in this model, is suggested to occur in three integrated activity domains: invention, diffusion, and deployment. A great number of factors that influence these activities are investigated and described, and different roles and incentives are discussed. Deviations from traditional innovation theory are for example: (a) integration of invention activities as having an impact on later events; (b) inclusion of the inventor/developer as a main actor also in the diffusion and deployment domains; (c) increased focus of the concept of technology cluster innovation, and (d) the rationality of use and abandonment of knowledge as factors to be included in the estimation of consequences of innovation. Finally, the thesis suggests a number of model and methodology improvements and policy implications for management of innovation in hospitals.