Remote diagnostics and monitoring using microwave technique – improving healthcare in rural areas and in exceptional situations

Interests towards wireless portable medical diagnostics and monitoring systems, which could be used outside hospital e.g. during pandemic or catastrophic situations, have increased recently. Additionally, portable monitoring solutions could partially address widely recognized challenges related to healthcare equality in rural areas. Microwave based sensing has recently been recognized as emerging technology for portable medical monitoring and diagnostics devices since they may enable development of safe, reliable, and low-cost solutions for future’s telemedicine. The aim of this paper is to present the basic idea of microwave -based medical monitoring and discuss its possibilities, advantages, and challenges. In particular, we show that microwaves could be exploited in three pre-diagnostics applications: 1) Detection of abnormalities in the brain with a helmet type of monitoring device, 2) Detection of breast cancer with a self-monitoring vest, 3) Detection of blood clots in leg with an antenna band. The technique is based on detecting differences in radio channel responses caused by the abnormalities having different dielectric properties than the surrounding tissues. Our results of realistic simulations and experimental measurements show that even small-sized abnormalities, e.g. tumors, can change channel characteristics in detectable level

Optical imaging and spectroscopy for the study of the human brain: status report.

This report is the second part of a comprehensive two-part series aimed at reviewing an extensive and diverse toolkit of novel methods to explore brain health and function. While the first report focused on neurophotonic tools mostly applicable to animal studies, here, we highlight optical spectroscopy and imaging methods relevant to noninvasive human brain studies. We outline current state-of-the-art technologies and software advances, explore the most recent impact of these technologies on neuroscience and clinical applications, identify the areas where innovation is needed, and provide an outlook for the future directions

Optical imaging and spectroscopy for the study of the human brain: status report

This report is the second part of a comprehensive two-part series aimed at reviewing an extensive and diverse toolkit of novel methods to explore brain health and function. While the first report focused on neurophotonic tools mostly applicable to animal studies, here, we highlight optical spectroscopy and imaging methods relevant to noninvasive human brain studies. We outline current state-of-the-art technologies and software advances, explore the most recent impact of these technologies on neuroscience and clinical applications, identify the areas where innovation is needed, and provide an outlook for the future directions

Optical imaging and spectroscopy for the study of the human brain: status report

This report is the second part of a comprehensive two-part series aimed at reviewing an extensive and diverse toolkit of novel methods to explore brain health and function. While the first report focused on neurophotonic tools mostly applicable to animal studies, here, we highlight optical spectroscopy and imaging methods relevant to noninvasive human brain studies. We outline current state-of-the-art technologies and software advances, explore the most recent impact of these technologies on neuroscience and clinical applications, identify the areas where innovation is needed, and provide an outlook for the future directions. Keywords: DCS; NIRS; diffuse optics; functional neuroscience; optical imaging; optical spectroscop

Cerebral oxygenation in newborn infants at risk

Een verminderd zuurstofgehalte in de hersenen van te vroeg geboren baby’s kan hersenschade tot gevolg hebben. UMCG-promovendus Elise Verhagen onderzocht het zuurstofgehalte in de hersenen van te vroeg geboren baby’s en de precieze gevolgen ervan. De gebruikte onderzoeksmethode, near-infrared spectroscopy (NIRS), lijkt een bruikbare methode te zijn om een verstoorde zuurstofvoorziening in de hersenen van te vroeg geboren baby’s vast te stellen. Verhagen vond nieuwe aanwijzingen dat roken tijdens de zwangerschap slecht is voor de zuurstofvoorziening van de hersenen van de pasgeboren baby. Daarmee biedt het onderzoek een nieuwe, extra reden om vrouwen dringend te adviseren te stoppen met roken voor zij zwanger raken, of in het geval direct te stoppen met roken zodra ze weten dat ze zwanger zijn. Roken tijdens de zwangerschap leidt tot een hogere zuurstofextractie in de hersenen bij te vroeg geboren baby’s in de eerste dagen na de geboorte, zo stelt Verhagen vast. Een hogere zuurstofextractie kan een aanwijzing zijn van een te lage bloeddoorstroming van de hersenen. De promovenda concludeert tevens dat het zuurstofgehalte in de hersenen tijdens de eerste dagen na de geboorte bij te vroeg geboren baby’s is geassocieerd met de neurologische ontwikkeling op 2- tot 3-jarige leeftijd. Relatief hoge en lage waarden zijn gerelateerd aan een slechtere cognitie. Een hoge zuurstofextractie is gerelateerd aan een slechtere motorische uitkomst

Acute Stroke Care: Strategies For Improving Diagnostics

Stroke is one of the leading causes of death and disability, with a high incidence of over 11 million cases annually worldwide. Costs of treatment and rehabilitation, loss of work, and the hardships resulting from stroke are a major burden both at the individual and at the societal level. Importantly, stroke therapies need to be initiated early for them to be effective. Thrombolytic therapy and mechanical thrombectomy are early treatment options of ischemic stroke. In hemorrhagic stroke, optimization of hemodynamic and hemostatic parameters is central, and surgery is considered in a subset of patients. Efficient treatment of stroke requires early and precise recognition of stroke at all stages of the treatment chain. This includes identification of patients with suspected acute stroke by emergency medical dispatchers and emergency medical services staff, and precise admission diagnostics by the receiving on-call stroke team. Success requires grasping the complexity of stroke symptoms that depend on the brain areas affected, and the plethora of medical conditions that can mimic stroke. The Helsinki Ultra-acute Stroke Biomarker Study includes a cohort of 1015 patients transported to hospital due to suspected acute stroke, as candidates for revascularization therapies. Based on this cohort, this thesis work has explored new avenues to improve early stroke diagnostics in all stages of the treatment chain. In a detailed investigation into the identification of stroke by emergency medical dispatchers, we analyzed emergency phone calls with missed stroke identification. We also combined data on dispatch and EMS and hospital records to identify causes for missing stroke during emergency calls. Most importantly, we found that a patient’s fall at onset and patient confusion were strongly associated with missed identification. Regarding the Face Arm Speech Test (FAST), the most likely symptom to be misidentified was acute speech disturbance. Using prehospital blood sampling of stroke patients, and ultrasensitive measurement, we investigated the early dynamics of the plasma biomarkers glial fibrillary acidic protein (GFAP) and total tau. Utilizing serial sampling, we demonstrate for the first time that monitoring the early release rate of GFAP can improve the diagnostic performance of this biomarker for early differentiation between ischemic and hemorrhagic stroke. In our analysis of early GFAP levels, we were able to differentiate with high accuracy two-thirds of all patients with acute cerebral ischemia from those with hemorrhagic stroke, supporting further investigation of this biomarker as a promising point-of-care tool for prehospital stroke diagnostics. We performed a detailed review of the admission diagnostics of our cohort of 1015 patients to explore causes and predictors of admission misdiagnosis. We then investigated the consequences of misdiagnosis on outcomes. We demonstrate in this large cohort that the highly optimized and rapid admission evaluation in our hospital district (door-to-needle times below 20 minutes) did not compromise the accuracy and safety of admission evaluation. In addition, we discovered targets for improving future diagnostics. Finally, our detailed neuropathological investigation of a case of cerebral amyloid angiopathy (CAA) -related hemorrhage after stroke thrombolysis provided unique tissue-level evidence for this common vasculopathy as a notable risk factor for intracranial hemorrhagic complications in the setting of stroke. These findings support research to improve the diagnostics of CAA, and the prediction of hemorrhagic complications associated with stroke thrombolysis. In conclusion, these proposed targets and strategies will aid in the future improvement and development of this highly important field of diagnostics. Our proof-of-concept discoveries on early GFAP kinetics help guide further study into this diagnostic approach just as highly sensitive point-of-care GFAP measurement instruments are becoming available. Finally, our results support the safety of worldwide efforts to optimize emergency department door-to- needle times when care is taken to ensure sufficient expertise is in place, highlighting the role of the on-call vascular neurologist as a central diagnostic asset.Aivohalvaus on yksi yleisimpiä kuolinsyitä ja pitkäkestoisen työkyvyttömyyden aiheuttajia. Aivohalvauksen aiheuttamat hoito- ja kuntoutuskustannukset, työkyvyn menetys ja arkielämän vaikeudet ovat mittava taakka sekä yksilön, läheisten että yhteiskunnan tasoilla. Tehokkaiden hoitojen vaatima nopeus edellyttää aivohalvauksen varhaista ja tarkkaa tunnistamista hoitoketjun kaikilla askelmilla. Tässä väitöskirjatyössä etsittiin uusia keinoja aivohalvauksen varhaisdiagnostiikan kehittämiseksi hätäkeskuksessa, ensihoidossa ja vastaanottavan sairaalan HYKS:n päivystyspoliklinikalla. Yksityiskohtainen analyysi aivohalvauksen tunnistamisesta hätäkeskuksessa osoitti, että potilaan kaatuminen ja sekavuus olivat puutteellisen tunnistamisen keskeisiä tekijöitä. Face Arm Speech Test (FAST) -seulontaoireista puhehäiriö oli todennäköisimmin väärin tunnistettu. Akuuttivaiheen verinäytteitä ja äärimmäisen herkkää määritysmenetelmää hyödyntäen tutkimme kahden verestä mitattavan merkkiaineen, aivojen tukikudoksen tähtisolujen säikeisen happaman proteiinin (GFAP) ja taun varhaista dynamiikkaa aivohalvauspotilailla. Osoitimme ensimmäistä kertaa, että GFAP:n varhaisen vapautumisnopeuden seurantaa sarjanäytteistä voidaan hyödyntää parantamaan tämän merkkiaineen erottelukykyä iskeemisen ja hemorragisen aivokudosvaurion varhaisdiagnostiikassa. Tulokset viittaavat siihen, että GFAP merkkiaine voisi olla jatkossa kehitettävissä ambulansseissa hyödynnettäväksi pikaverikokeeksi, joka auttaisi aivohalvauksen eri muotojen varhaisessa erottelussa. Päivystysdiagnostiikkaan keskittyvässä osatyössä osoitimme ensimmäistä kertaa suuressa aineistossa, että sairaanhoitopiirissämme vuosia optimoitu erittäin nopea vastaanottoarviointi (liuotushoidon mediaaniviive alle 20 minuuttia sisältäen pään kuvauksen) ei vaaranna aivohalvauspotilaiden diagnostiikan tarkkuutta ja hoidon turvallisuutta. Tässä väitöskirjatyössä esitetyt kehityskohteet ja menetelmät auttavat tämän erittäin tärkeän diagnostisen alan tulevassa kehitystyössä. Työssä kuvatut tulokset sisältävät uraauurtavia havaintoja verestä mitattavan GFAP merkkiaineen kinetiikan käytöstä aivohalvauksen varhaisdiagnostiikassa ja tukevat sairaalapäivystysarvion diagnostista tarkkuutta HYKS:n tunnetusti erittäin nopeassa liuotushoitoketjussa

Towards Microwave Detection of Thromboses

Stroke is estimated to be the second most common cause of death with hugeburdens and costs for the patient and society. Since the treatment given to a stroke patient depends on the type of stroke they have, a fast and reliable diagnosis of the stroke type is needed before any treatment can be started. In general, the treatment is more effective the sooner it is started. Thrombectomy is an interventional treatment for patients with an occlusion (thrombosis) in a large artery that is only performed in a limited number of hospitals, thus early detection can support the pre-hospital decision-making process and help decreasing the time to treatment start. The aim of this work is to investigate and develop a method for pre-hospital diagnosis of ischemic stroke by using a microwave diagnosis setup and Contrast-Enhancement Agent (CEA). We propose to exploit the asymmetry created in the brain as a result of partial or full blockage of the arteries due to thromboses. This asymmetry is enhanced with the use of CEA and can be captured by the EM waves transmitted and received by the antennas on the head.The microwave diagnosis setup consists of several antennas placed on thebody. The multipath interference caused by the waves traveling on the surfaceof the body is a factor that limits the detection accuracy of this system. In the present study, a Dielectric Rod Antenna (DRA) is designed to address this challenge with a Self Grounded Bow-Tie Antenna (SGBTA) as the wave exciter. It was shown that DRA can reduce the surface wave power up to 10 dB in comparison with that of SGBTA while increasing its bandwidth by 72%.Preliminary results obtained from measurements on sheep are promising