Poly(urethane)s and poly(urethane-urea)s (PUU) are nearly ubiquitous, having been in existence since before the Second World War. Spandex, a poly(urethane-urea) elastomeric fiber, is found in nearly all articles of apparel as well as in an increasing array of other consumer items. The technology and chemistry of spandex is largely unchanged since its inception in the late 1950s, with the majority of spandex employing poly(tetramethylene ether glycol) as soft segments. Recent developments in catalyst technology have resulted in the production of ultra-low monol content poly(propylene glycol) (PPG), which is nearly difunctional (f=1.95+). This enhancement in difunctionality has potentially enabled the use of PPG as a spandex soft segment with potential spandex processing, performance, and economic benefits. PPG-based spandex elastomers were evaluated in both film and fiber form for the purpose of investigating morphological, orientational, mechanical, and thermal properties with the goal of understanding relationships between chemistry, morphology and properties. Key variables of interest were soft segment molecular weight (MW), molecular weight distribution (MWD), and composition, and hard segment content and composition. Of those, the influence of the molecular weight distribution of the polyol used for soft segments was of foremost interest and had previously been largely neglected during the course of poly(urethane) and poly(urethane-urea) research. It was found that over the range of PUU compositions suitable for production of spandex, that hard segment content and composition had little effect upon the morphology and thermal and mechanical properties. Appreciable trends as functions of soft segment molecular weight were observed. The soft segment MWD was adjusted through the addition of a low molecular weight homolog of PPG, tri(propylene glycol) (TPG), decreasing the number average soft segment MW. The results of these experiments were contrary to those for variation of soft segment molecular weight. It was determined that the low MW portion of the polyol MWD contributes to the building of hard segments in addition to or in lieu of soft segments. Incorporation of TPG in the PUUs resulted in larger, presumably less cohesive, hard domains and increased hard segment content. The TPG containing materials had enhanced tensile properties, less permanent set, and less residual orientation after deformation. These materials proved quite comparable to those using PTMEG soft segments. Comparison of film and fiber PUUs revealed only minor differences, implying that the trends and conclusions drawn from the study of films with spandex-like compositions would also hold for fibers. The key difference between films and fibers is that fibers maintain some residual ordering and orientation due to drawing of the fibers during processing. Of the processing variables investigated, none impacted the morphology as determined from small angle x-ray scattering. It was concluded, that of the various compositional variables germane to spandex, the polyol MW and MWD played key roles in development of morphology, and hence properties. The role of polyol MWD had been woefully neglected during the development of spandex previously, and was observed to be a critical variable. / Ph. D.

Penile plethysmography is amongst the best measures for prediction of sexual recidivism and has been extensively researched. However, there are a variety of criticisms regarding use of penile plethysmography (PPG), including financial investment, significant training needs, lack of standardization, intrusive nature of the measure, extensive time for testing, and inability to use PPG with all groups of sexual offenders (e.g., women and adolescents). Viewing time has been studied, though not as extensively as PPG, regarding detection of sexual interest. This study examined the relationship between Monarch 21 PPG and Affinity viewing time variables, including responses to individual stimuli, a sex deviance differential, and a sex deviance ratio. It was predicted that there would be a significant positive correlation between key variables of the Monarch 21 PPG and Affinity. Overall, the associations found between the Monarch 21 PPG and the Affinity were significant, although the magnitudes of the associations were modest. When considering sexual deviance ratios and differentials (as is typically utilized in PPG literature), there was a small, but significant association between the Monarch 21 PPG and the Affinity. Consequently, it is recommended that more research be done comparing these two sets of measures, further evaluating the Affinity and its' predictive validity, and examining the complex arousal pattern shapes, rather than focusing only on a series of discrete variables.

Monitoring stress in real-time, in a non-laboratory environment can be benecial in several applications. One of these, which have been the motivation for this thesis, is to to perform this measurement during Attention decit hyperactivity disorder (ADHD) diagnosis. Monitoring several physiological responses to internal or external stimuli in a single soft-real-time system is nota solution widely used in an application like this. The thesis starts by studying several stress related responses in detail. Sensors for all of the responses are not implemented nor is it possible toimplement in to the desired system. After the study is was decided to implement two measurement modules. The first a Photo-plethysmogrophy (PPG) measurement module to measure heart rate and also estimate breathing. This module is prepared for estimating arterial blood oxygen levels but the calculation or verification have not been done. The second is Skin Conductance (SC) measurement module and in to both ofthese add a temperature sensor to measure the temperature of the skin. Time constraints limit the SC module to only be presented in theory. The PPG module on the other hand have been realisedin a prototype. This prototype performs the measurement in transmissive mode on the left earlobe, which leaves the hands free and it does not affect the hearing on that ear. The prototype giveout acceptable signal quality when good contact with the measurement site is achieved. The signalinterpretation, such as performing the signal analysis to count the beats per minute, is outside thescope of this thesis and will therefore not be presented but the signals can be seen in figures. / Att mäta stress i realtid i verkliga situationer kan vara fördelaktigt för flera applikationer. Det som har legat som grund för denna uppsats är att kunna mäta stress under ADHD diagnostisering. Genom att kombinera de vanliga testerna med stressnivåer hos patienten hoppas man kunna utveckla nya metoder för diagnostisering. Att mäta fera parametrar samtidigt i realtid är inte något ofta utförs idag. För att komma igång har fera kroppsliga funktioner som påverkas på olika sätt av stress studerats. Alla dessa funktioner kan inte inkluderas i det system som önskas konstrueras antingen på grund av systemets karaktär eller på grund tidsbrist. Efter att undersökningen var klar beslutades det att konstruera två moduler. Den första använder en mätteknik som kallas PPG och används för att mäta hjärtfrekvens, även andningsfrekvensen estimeras och modulen är förberedd för att estimera blodsyre nivåa men signalbehandling och validering för detta är inte gjord. Den andra modulen mäter resistans i huden. I dessa moduler lades även till en temperatur sensor för att mäta hudtemperaturen. Tidsbrist har gjort att endast en av dem två modulerna kunnat realiserats. Den som realiserat är PPG modulen och modulen för hudresistans presenteras endast teoretiskt. PPG modulen genomför matningen med en transmissiv teknik på vänster öra och ger ut en acceptabel signal kvalité om sensorn får bra kontakt. Arbetet är avgränsat och inkluderar inte signalanalysen av signalen däremot visualiseras signalen i figurer.

<p>Examensarbetet är utfört på Linköpings Universitet, Institutionen för Medicinsk Teknik och bygger på att undersöka möjligheterna för trådlös överföring av mätvärden via Bluetooth. Mätningarna gäller två olika hårdvaror som med metoden PPG mäter blodflöde, en ny förenklad hårdvara och en mer avancerad och tidigare utvecklad hårdvara. Arbetet är tvådelat, under första delen upprättades en kommunikation med Bluetooth och två metoder för överföring av data undersöktes. Under andra delen togs ett gränssnitt fram i utvecklingsmiljön LabVIEW för styrning av hårdvarorna samt för åskådliggörandet av mätdata. Metoderna som undersöktes för dataöverföring är att antingen kontinuerligt skicka samplat data direkt från en AD-omvandlare eller att fylla bluetoothmodulens minne för att därefter skicka samtliga värden samtidigt. För utvärdering av vilken metod som passar bäst för ändamålet diskuteras för- och nackdelar, samplingshastigheter undersöks och redovisas med hjälp av tabeller och grafer. Examensarbetet har resulterat i en grund för fortsatt utveckling av trådlös anpassning av mättekniska ändamålinom medicinsk teknik.</p>

Examensarbetet är utfört på Linköpings Universitet, Institutionen för Medicinsk Teknik och bygger på att undersöka möjligheterna för trådlös överföring av mätvärden via Bluetooth. Mätningarna gäller två olika hårdvaror som med metoden PPG mäter blodflöde, en ny förenklad hårdvara och en mer avancerad och tidigare utvecklad hårdvara. Arbetet är tvådelat, under första delen upprättades en kommunikation med Bluetooth och två metoder för överföring av data undersöktes. Under andra delen togs ett gränssnitt fram i utvecklingsmiljön LabVIEW för styrning av hårdvarorna samt för åskådliggörandet av mätdata. Metoderna som undersöktes för dataöverföring är att antingen kontinuerligt skicka samplat data direkt från en AD-omvandlare eller att fylla bluetoothmodulens minne för att därefter skicka samtliga värden samtidigt. För utvärdering av vilken metod som passar bäst för ändamålet diskuteras för- och nackdelar, samplingshastigheter undersöks och redovisas med hjälp av tabeller och grafer. Examensarbetet har resulterat i en grund för fortsatt utveckling av trådlös anpassning av mättekniska ändamålinom medicinsk teknik.

Despite having the numerous evolved heart rate measuring devices and progress in their development over the years, there always remain the challenges of modern signal processing implementation by a comparatively small size wearable device. This thesis paper presents a wearable reflectance photoplethysmography (PPG) sensor system for measuring the heart rate of a user both in steady and moving states. The size and, power consumption of the device are considered while developing, to ensure an easy deployment of the unit at the measuring site and the ability to power the entire unit with a battery .The selection of both the electronic circuits and signal processing techniques is based on their sensitivity to PPG signals, robustness against noise inducing artifacts and miniaturization of the entire measuring unit. The entire signal chain operates in the discrete-time, which allows the entire signal processing to be implemented in firmware on an embedded microprocessor. The PPG sensor system is implemented on a single PCB that consumes around 7.5mW of power. Benchmarking tests with standard heart rate measuring devices reveal that the developed measurement unit (combination of the PPG sensor system, and inertial measurement unit (IMU) developed in-house at Acreo Swedish ICT, and a battery) is comparable to the devices in detecting heart rate even in motion artifacts environment. This thesis work is carried out in Acreo Swedish ICT, Gothenburg, Sweden in collaboration with MidSweden University, Sundsvall, Department of Electronics Design. This report can be used as ground work for future development of wearable heart rate measuring units at Acreo Swedish ICT.

Pulse-shaped signals require a tool that can accurately analyse and identify the peak characteristics in the spectrum. One recently developed tool available to analyse non-stationary pulse-shaped waveforms with a suitable peak reconstruction is semiclassical signal analysis (SCSA). SCSA is a signal representation method that decomposes a real positive signal y(t) into a set of squared eigenfunctions through the discrete spectrum of the Schr¨odinger operator. In this study, we apply SCSA in two directions. First, we propose a new signal denoising method based on the signal curvature. We use this technique to show that denoising the pulse-shaped signal by regularizing its curvature can yield better peak-preserving performance than traditional filters, such as moving average filter or wavelet. Second, we apply SCSA to biomedical signal analysis. The localization abilities of L2 normalized squared eigenfunctions are used in blood pressure (BP) estimation. Based on existing properties, the systolic and diastolic phases are separated into photoplethysmograms (PPGs), which are then used as features for BP estimation. In addition, the Multiparameter Intelligent Monitoring in Intensive Care (MIMIC II) database is used to test the application with more than 8000 subjects. Another application uses SCSA features to characterize EEG and MEG signals, leading to more accurate epileptic spike detection and diagnosis in epileptic patients. Both applications are validated using real datasets, which guarantees statistical reliability and motivates future work of this model in clinical applications and equipment designs.

To perform a physical performance test is a good way to keep track of one’s health and can be beneficial to find evidence of deviations in the body. This thesis focuses on the development of a mobile-based heart rate algorithm that can be used with the Queens College Step Test, on the behalf of Mobistudy. Mobistudy wants to include such a test in their mobile application which aims to become a tool for researchers to use to gather data. The algorithm uses the mobile device’s camera to collect data from the user’s finger and uses that data to calculate the heart rate. The algorithm was first tested with data collected during the development and the results has an average error of less than 5% and a standard deviation of less than 3%. Two participants between the age of 20-25 performed three sets each of the Queens College Step Test and the results showed that the algorithm was accurate in its estimation of the heart rate after the test. / Genom att utföra ett test av ens fysiska prestanda kan man utvärdera ens hälsostatus och upptäcka indikationer på avvikelser i kroppen. Syftet med detta arbete är att utveckla en mobilbaserad algoritm som kan beräkna och uppskatta ens puls när man utför the Queens College Step Test på begäran av Mobistudy. Mobistudy vill inkludera detta test i deras mobilapplikation som fokuserar på att kunna användas som ett verktyg inom forskning för att samla in data. Algoritmen använder sig av mobilens kamera för att samla in data från användarens finger och använder den insamlade data för att beräkna pulsen. Algoritmen testades först gentemot data som samlades in vid utvecklingsstadiet och resultatet visade på att genomsnittliga felet var under 5% samt att standardavvikelsen var under 3%. Två deltagare mellan åldern 20 och 25 utförde tre tester var utav the Queens College Step Test och resultatet visade att algoritmen var tillräckligt noggrann i sin uppskattning av pulsen efter ett utfört test.

We addressed two interesting video-based health measurements. First is video-based Heart Rate (HR) estimation, known as video-based Photoplethysmography (PPG) or videoplethysmography (VHR). We adapted an existing video-based HR estimation method to produce more robust and accurate results. Specifically, we removed periodic signals from the recording environment by identifying (and removing) frequency clusters that are present the face region and background. This adaptive passband filter generated more accurate HR estimates and allowed other applied filters to work more effectively. Measuring HR at the presence of motions is one of the most challenging problems in recent VHR studies. We investigated and described the motion effects in VHR in terms of the angle change of the subject’s skin surface in relation to the light source. Based on this understanding, we discussed the future work on how we can compensate for the motion artifacts. Another important health information addressed in this thesis is Videosomnography (VSG), a range of video-based methods used to record and assess sleep vs. wake states in humans. Traditional behavioral-VSG (B-VSG) labeling requires visual inspection of the video by a trained technician to determine whether a subject is asleep or awake. We proposed an automated VSG sleep detection system (auto-VSG) which employs motion analysis to determine sleep vs. wake states in young children. The analyses revealed that estimates generated from the proposed Long Short-term Memory (LSTM)-based method with long-term temporal dependency are suitable for automated sleep or awake labeling.

<p>The aim of the work was to investigate the possibility to combine information from PPG and bio-acoustic technology to extract information that is related to the blood pressure. The measurements have been carried out with several different configurations. First the relation between arterial sounds and the PPG-signal was studied. After those measurements with both PPG and the bio- acoustic technique was concluded on people in different positions and after riding a bike. The goal was to vary the blood pressure. The conclusion that can be drawn in this report is that the bio-acoustic and the PPG-signal in peripheral arteries have the same source. That implies that arterial sounds are a product of turbulence when the pulse wave passes by. Further it can be assumed that it is the first heart sound that is represented in the arterial sounds. The time before and after the arterial sound in one heart cycle vary whit the blood pressure. There relationship seems also to vary with the bloodpressure but it vary differently under different conditions.</p>