LactateStat: Bärbar elektronik och mjukvara för realtidsövervakning av laktat i svett

Lactate is an important biomarker in sports and the lactate threshold concept is one of the best indicators of endurance performance in an athlete. However, to quantify the lactate threshold, an invasive method to take a blood sample must be used. Limitations for this method include stopping the active exercise for blood sampling and no real-time feedback. Instead, a novel non-invasive wearable biosensor can be used to measure the lactate concentration in sweat. The sensor generates an electrical current depending on the lactate concentration in the sweat, and therefore must an electronic device called a potentiostat be used to condition the current. However, available potentiostats are not suitable for use in sports where form factor, battery life and wireless connectivity is important. This thesis aims to solve this by developing a wearable device and software which can be used to measure the lactate concentration in sweat in real-time during exercise. The development process consisted of the determination of specifications, prototype development and thorough laboratory and on-body testing. Finally, a novel wearable device and software capable of real-time lactate measurements in sweat during exercise were presented. The device, called LactateStat, was 58mm ∗ 55mm ∗ 13mm, the current consumption was only 7.8mA, the current measurement resolution was 0.5 nA, the limit of detection was 0.45 nA and the current measurement range was around 750 μA. LactateStat is one of the first of its kind and provides a base for future development as the hardware, firmware and software resources are provided as open-source. Laktat är en viktig biomarkör inom idrott och konceptet laktattröskel är en av de bästa indikatorerna för uthållighet hos en idrottsutövare. Men för att mäta laktattröskeln krävs en invasiv metod som går ut på att man tar ett blodprov. Begränsningarna med denna metod är bland annat att idrottsutövningen måste stoppas för att ta ett blodprov och att man inte får realtidsåterkoppling. I stället kan en liten och icke-invasiv bärbar biosensor användas för att mäta laktatkoncentrationen i svett. Sensorn genererar en elektrisk ström beroende på laktatkoncentrationen i svetten och en enhet som kallas potentiostat måste därför användas för att mäta denna ström. Tillgängliga potentiostater är dock inte lämpliga för användning inom sport där formfaktor, batteritid och trådlös kommunikation är viktigt. Denna avhandling har som syfte att lösa detta genom att utveckla en bärbar enhet och mjukvara som kan användas för att mäta laktatkoncentrationen i svett i realtid under träning. Utvecklingsprocessen bestod av bestämning av specifikationer, framtagning av en prototyp och noggrann laboratorie- och kroppstestning. Som resultat presenterades en banbrytande bärbar enhet och mjukvara som kan mäta laktat i realtid i svett under träning. Enheten, som kallades LactateStat, var 58mm * 55mm * 13mm, den aktiva strömförbrukningen var 7.8mA, den bästa mätupplösningen för ström var 0.5 nA, detektionsgränsen var 0.45 nA och det maximala mätområdet för ström var ca. 750 μA. LactateStat är en av de första i sitt slag och ger en bas för framtida utvecklingsarbete eftersom hårdvaru-, programvaru- och mjukvaruresurserna tillhandahålls som öppen källkod.

LactateStat: Bärbar elektronik och mjukvara för realtidsövervakning av laktat i svett

Lactate is an important biomarker in sports and the lactate threshold concept is one of the best indicators of endurance performance in an athlete. However, to quantify the lactate threshold, an invasive method to take a blood sample must be used. Limitations for this method include stopping the active exercise for blood sampling and no real-time feedback. Instead, a novel non-invasive wearable biosensor can be used to measure the lactate concentration in sweat. The sensor generates an electrical current depending on the lactate concentration in the sweat, and therefore must an electronic device called a potentiostat be used to condition the current. However, available potentiostats are not suitable for use in sports where form factor, battery life and wireless connectivity is important. This thesis aims to solve this by developing a wearable device and software which can be used to measure the lactate concentration in sweat in real-time during exercise. The development process consisted of the determination of specifications, prototype development and thorough laboratory and on-body testing. Finally, a novel wearable device and software capable of real-time lactate measurements in sweat during exercise were presented. The device, called LactateStat, was 58mm ∗ 55mm ∗ 13mm, the current consumption was only 7.8mA, the current measurement resolution was 0.5 nA, the limit of detection was 0.45 nA and the current measurement range was around 750 μA. LactateStat is one of the first of its kind and provides a base for future development as the hardware, firmware and software resources are provided as open-source. Laktat är en viktig biomarkör inom idrott och konceptet laktattröskel är en av de bästa indikatorerna för uthållighet hos en idrottsutövare. Men för att mäta laktattröskeln krävs en invasiv metod som går ut på att man tar ett blodprov. Begränsningarna med denna metod är bland annat att idrottsutövningen måste stoppas för att ta ett blodprov och att man inte får realtidsåterkoppling. I stället kan en liten och icke-invasiv bärbar biosensor användas för att mäta laktatkoncentrationen i svett. Sensorn genererar en elektrisk ström beroende på laktatkoncentrationen i svetten och en enhet som kallas potentiostat måste därför användas för att mäta denna ström. Tillgängliga potentiostater är dock inte lämpliga för användning inom sport där formfaktor, batteritid och trådlös kommunikation är viktigt. Denna avhandling har som syfte att lösa detta genom att utveckla en bärbar enhet och mjukvara som kan användas för att mäta laktatkoncentrationen i svett i realtid under träning. Utvecklingsprocessen bestod av bestämning av specifikationer, framtagning av en prototyp och noggrann laboratorie- och kroppstestning. Som resultat presenterades en banbrytande bärbar enhet och mjukvara som kan mäta laktat i realtid i svett under träning. Enheten, som kallades LactateStat, var 58mm * 55mm * 13mm, den aktiva strömförbrukningen var 7.8mA, den bästa mätupplösningen för ström var 0.5 nA, detektionsgränsen var 0.45 nA och det maximala mätområdet för ström var ca. 750 μA. LactateStat är en av de första i sitt slag och ger en bas för framtida utvecklingsarbete eftersom hårdvaru-, programvaru- och mjukvaruresurserna tillhandahålls som öppen källkod.

Geant4 simuleringar av partikelterapi och förfinande av användargränssnitt

Radiotherapy is one of the most used methods for treating cancer and the most common way to execute such treatments is to irradiate tumors with high energy photons. This can damage healthy tissue along the irradiation line. By using hadron therapy and instead irradiate the tumor with charged particles (protons or Carbon 12 ions), the energy can be concentrated to a more specific place in the body. However, the method is not well studied and the tools available for simulating hadron therapy can be hard to use. When simulating hadron therapy and other nuclear interactions a large amount of calculations need to be executed. Monte Carlo methods is a numerical method to solve equations based on repeated number sampling and is used in the simulation program Geant4. Hadron therapy was simulated with Geant4 and the data was analyzed with the data analysis framework ROOT. New macros and analysis scripts were created with the intention to help new Geant4 users. The aim to make Geant4 easier to use was partially met. The implementation of code for the low energy region of Carbon 12 projectiles was unsuccessful

Geant4 simuleringar av partikelterapi och förfinande av användargränssnitt

Radiotherapy is one of the most used methods for treating cancer and the most common way to execute such treatments is to irradiate tumors with high energy photons. This can damage healthy tissue along the irradiation line. By using hadron therapy and instead irradiate the tumor with charged particles (protons or Carbon 12 ions), the energy can be concentrated to a more specific place in the body. However, the method is not well studied and the tools available for simulating hadron therapy can be hard to use. When simulating hadron therapy and other nuclear interactions a large amount of calculations need to be executed. Monte Carlo methods is a numerical method to solve equations based on repeated number sampling and is used in the simulation program Geant4. Hadron therapy was simulated with Geant4 and the data was analyzed with the data analysis framework ROOT. New macros and analysis scripts were created with the intention to help new Geant4 users. The aim to make Geant4 easier to use was partially met. The implementation of code for the low energy region of Carbon 12 projectiles was unsuccessful

Epidemiology, classification, treatment and mortality of Talus fractures : An observational study of 1794 talus fractures from the Swedish Fracture Register

BACKGROUND: Epidemiological data on talus fractures from large nationwide and multicenter studies are rare. This study aims to describe the epidemiology, fracture classification and treatment regimens of talus fractures in a large adult Swedish population. METHODS: This observational study is based on data from the Swedish Fracture Register (SFR) including talar fractures in patients ≥18 with a sustained fracture between 2012 and 2021. Epidemiological data on sex, age, injury date, injury mechanism and type (high or low energy trauma), fracture classification (side, type), initial treatment and mortality were analysed. RESULTS: We included 1794 talus fractures (1757 patients, 60 % men). Mean age was 40.3 years (range 18-96), and a biphasic age distribution was seen in women. High-energy trauma caused 33 % of all talus fractures. Of all talus fractures, 817 (45.5 %) were classified as AO/OTA type A fractures (avulsion), 370 (20.6 %) as type B (neck) and 435 (24.2 %) as type C (body). The remaining 172 (9.6 %) talus fractures were not classified/unclassifiable. Men were in the majority in all fracture groups except A1. For type A1-3, B1 and C1-2 fractures, most patients were treated non-operatively; in B2-3 and C3 fractures most patients received operative management. Fracture fixation with screws was the dominating surgical treatment. The overall 30-day mortality was 0.2 %. CONCLUSION: Talus fractures are most commonly encountered in young and middle-aged men. In contrast to men, a biphasic age distribution was observed in women. Approximately half of the talus fractures are avulsions. Operative treatment, mostly screw fixation, is performed in more complex fracture configurations (B2, B3 and C3 fractures). LEVEL OF EVIDENCE: IV, retrospective observational cohort study

Fully Integrated Wearable Device for Continuous Sweat Lactate Monitoring in Sports.

The chemical digitalization of sweat using wearable sensing interfaces is an attractive alternative to traditional blood-based protocols in sports. Although sweat lactate has been claimed to be a relevant biomarker in sports, an analytically validated wearable system to prove that has not yet been developed. We present a fully integrated sweat lactate sensing system applicable to in situ perspiration analysis. The device can be conveniently worn in the skin to monitor real-time sweat lactate during sports, such as cycling and kayaking. The novelty of the system is threefold: advanced microfluidics design for sweat collection and analysis, an analytically validated lactate biosensor based on a rational design of an outer diffusion-limiting membrane, and an integrated circuit for signal processing with a custom smartphone application. The sensor covering the range expected for lactate in sweat (1-20 mM), with appropriate sensitivity (-12.5 ± 0.53 nA mM-1), shows an acceptable response time (<90 s), and the influence of changes in pH, temperature, and flow rate are neglectable. Also, the sensor is analytically suitable with regard to reversibility, resilience, and reproducibility. The sensing device is validated through a relatively high number of on-body tests performed with elite athletes cycling and kayaking in controlled environments. Correlation outcomes between sweat lactate and other physiological indicators typically accessible in sports laboratories (blood lactate, perceived exhaustion, heart rate, blood glucose, respiratory quotient) are also presented and discussed in relation to the sport performance monitoring capability of continuous sweat lactate

Utvikling av indikatorer på NCD området knyttet til rapportering for den globale og nasjonale NCD strategien

Norge har sluttet seg til WHO sitt mål om 25% reduksjon 2010 til 2025 i for tidlig død som følge av de fire ikke-smittsomme sykdommene (noncommunicale disease, NCD); kreft, hjerte- og karsykdom, diabetes og kronisk lungesykdom. Bakgrunnen er at disse fire sykdomsgruppene langt på vei kan forebygges ved å redusere de fire felles risikofaktorene røyking, usunn kost, stillesitting og skadelig bruk av alkohol. I alt 25 indikatorer er definert i den globale NCD-strategien. En norsk NCD-strategi er vedtatt. Folkehelseinstituttet fikk i 2016 i oppdrag fra Helse og omsorgsdepartementet i samarbeid med Helsedirektoratet å bidra til utvikling av indikatorer på NCD området knyttet til rapporterering av den globale og nasjonale NCD-strategien. Folkehelseinstituttet skal primært arbeide med rapporteringen av indikatorene knyttet opp mot NCD sykdommene og risikofaktorene, og Helsedirektoratet skal primært rette sitt NCD arbeid inn mot helsetjenesten

Prospective observational cohort study on grading the severity of postoperative complications in global surgery research

Background The Clavien–Dindo classification is perhaps the most widely used approach for reporting postoperative complications in clinical trials. This system classifies complication severity by the treatment provided. However, it is unclear whether the Clavien–Dindo system can be used internationally in studies across differing healthcare systems in high- (HICs) and low- and middle-income countries (LMICs). Methods This was a secondary analysis of the International Surgical Outcomes Study (ISOS), a prospective observational cohort study of elective surgery in adults. Data collection occurred over a 7-day period. Severity of complications was graded using Clavien–Dindo and the simpler ISOS grading (mild, moderate or severe, based on guided investigator judgement). Severity grading was compared using the intraclass correlation coefficient (ICC). Data are presented as frequencies and ICC values (with 95 per cent c.i.). The analysis was stratified by income status of the country, comparing HICs with LMICs. Results A total of 44 814 patients were recruited from 474 hospitals in 27 countries (19 HICs and 8 LMICs). Some 7508 patients (16·8 per cent) experienced at least one postoperative complication, equivalent to 11 664 complications in total. Using the ISOS classification, 5504 of 11 664 complications (47·2 per cent) were graded as mild, 4244 (36·4 per cent) as moderate and 1916 (16·4 per cent) as severe. Using Clavien–Dindo, 6781 of 11 664 complications (58·1 per cent) were graded as I or II, 1740 (14·9 per cent) as III, 2408 (20·6 per cent) as IV and 735 (6·3 per cent) as V. Agreement between classification systems was poor overall (ICC 0·41, 95 per cent c.i. 0·20 to 0·55), and in LMICs (ICC 0·23, 0·05 to 0·38) and HICs (ICC 0·46, 0·25 to 0·59). Conclusion Caution is recommended when using a treatment approach to grade complications in global surgery studies, as this may introduce bias unintentionally