The Feasibility of Using a Smartphone Magnetometer for Assisting Needle Placement

Minimally invasive surgical procedures often require needle insertion. For these procedures, efficacy greatly depends on precise needle placement. Many methods, such as optical tracking and electromagnetic tracking, have been applied to assist needle placement by tracking the real-time position information of the needle. Compared with the optical tracking method, electromagnetic tracking is more suitable for minimally invasive surgery since it has no requirement of line-of-sight. However, the devices needed for electromagnetic tracking are usually expensive, which will increase the cost of surgery. In this study, we presented a low-cost smartphone-based permanent magnet tracking method compatible with CT imaging and designed a 3D printed operation platform to assist with needle placement prior to needle insertion during minimally invasive surgery. The needle positioning accuracy of this method was tested in an open air test and a prostate phantom test in a CT environment. For these two tests, the average radial errors were 0.47 and 2.25 mm, respectively, and the standard deviations were 0.29 and 1.63, respectively. The materials and fabrication required for the presented method are inexpensive. Thus, many image-guided therapies may benefit from the presented method as a low-cost option for needle positioning prior to needle insertion

Design and Development of Imaging Platforms for Phenotypic Characterization of Early Zebrafish

Der Zebrabärbling hat sich in den letzten Jahrzehnten als ein beliebter und vielversprechender Modellorganismus herausgestellt. Mit seiner Hilfe werden zunehmend die grundlegenden biologischen Funktionsweisen von Wirbeltieren untersucht und anhand der Erkenntnisse neue Therapien und Medikamente für Krankheiten entwickelt. Zusätzlich hat sich die Verhaltensforschung als Gebiet mit hohem Potential für neue Entdeckungen entpuppt, da es hier möglich ist, deutlich feinere Unterscheidungen und Effekte nachzuvollziehen als es bei stark abgegrenzten Endpunkten wie Verformungen oder Toxizität der Fall ist. Im frühen Stadium bis fünf Tage nach Befruchtung zeigen die Embryonen und Larven des Zebrabärblings einige charakteristische Verhaltensweisen, die durch künstliche Stimulation hervorgerufen werden können. Noch in der Eischale bei einem Alter von nur 30 bis 42 Stunden nach der Befruchtung reagieren die Embryonen auf einen Lichtblitz mit erhöhter Bewegung, der sogenannten Photomotor Response. Bei wiederholtem Belichten bleibt diese Reaktion aus, was als ein typisches Verhaltensmuster interpretiert werden kann. Werden die Embryonen jedoch Chemikalien oder Mutationen ausgesetzt, kann sich dieses Muster verändern und es können Rückschlüsse über die Funktionsweise der verursachenden Methoden gewonnen werden. Als zusätzliche Verhaltensweisen lassen sich die beiden Schreckreaktionen auf Vibration und Berührung nutzen. Bereits in der Eischale lassen sich die Embryonen durch Berührung zum Bewegen bringen. Sobald sie in einem Alter von ca. drei Tagen nach Befruchtung geschlüpft sind, wird die Reaktion als C-Krümmung bezeichnet, da die Larve eine charakteristische Biegung entlang ihrer Körperachse einnimmt bevor sie davonschwimmt. Dasselbe gilt für die Vibrationsreaktion ab einem Alter von ca. fünf Tagen nach Befruchtung. Um diese Verhalten sinnvoll nutzen zu können sind automatisierte Lösungen notwendig, die die Vorbereitung, die Abläufe und die Analyse soweit vereinfachen, dass kaum noch menschliches Eingreifen notwendig ist. Nur so kann der notwendige Durchsatz und die Reproduzierbarkeit gewährleistet werden um statistisch aussagekräftige Effekte nachzuweisen. Aus diesem Grund wurden drei unabhängige mechatronische Systeme entwickelt, die je eines der drei genannten Verhaltensmuster automatisiert auslösen, aufzeichnen und analysieren können. Dazu waren neben der Hard- und Softwareentwicklung auch biologische Vorgehensweisen notwendig um die Systeme zu validieren und sie bereits in ersten biologischen Untersuchungen einzusetzen. Für das PMR System wurde ein hochautomatisierter Versuchsablauf entwickelt, der anhand eines Roboters die Embryonen zur Vorbereitung sortiert und anschließend in einem automatisierten Mikroskop mit vollständig eigenentwickelter Steuerungssoftware die Aufzeichnung der Reaktion gewährleistet. Anschließend können die Rohdaten in Form von Videos automatisiert analysiert werden um numerische Daten aus den Bildreihen zu extrahieren. Das Vibrationssystem umfasst einen neuentwickelten Vibrationserreger in Form eines modifizierten Lautsprechers, der es erlaubt, mehrere Proben parallel zu untersuchen. Dazu wurde der Erreger ausgiebig charakterisiert um zu gewährleisten, dass die erzielten Beschleunigungswerte sowie die Impulsdauer und Frequenz den angestrebten Werten von 14 g, 1 ms und 500 Hz entsprechen. Durch den Einsatz von Beschleunigungssensoren wurden die Erreger kalibriert und die Steuerungssoftware an die Ergebnisse so angepasst, dass ein einheitlicher Effekt zwischen den Erregern gewährleistet ist. Die Implementierung einer Hochgeschwindigkeitskamera erlaubt die Aufzeichnung der Reaktion bei bis zu 1000 Bildern pro Sekunde, was aufgrund der äußerst schnellen Reaktionszeit der Larven im Millisekundenbereich notwendig ist um den vollen Umfang der Reaktion abzubilden. Um Hochdurchsatzversuche zur Berührung der Larven zu ermöglichen, wurde das erste automatisierte System entwickelt, welches durch den Einsatz einer motorisiert positionierbaren Nadel einen computergesteuerten Berührungsvorgang ermöglicht. Ein berührungsempfindliches Mehrachsensystem wurde so konstruiert, dass der Nutzer über eine grafische Oberfläche das System fernsteuern kann und so die subjektiven und unnötig langwierigen Aspekte von manuellen Versuchsaufbauten umgangen werden können. Das System wurde mit einer digitalen Objekterkennung so erweitert, dass auch autonome Versuche möglich wurden. Die Systeme wurden im Rahmen von mehreren biologischen Untersuchungen am ITG ausgiebig getestet. Mit Hilfe des PMR Systems wurde eine mehrere hundert Proben umfassende Sammlung von Cannabinoid-ähnlichen Substanzen auf ihre neuroaktive Wirkung untersucht. So konnten charakteristische Reaktionsmuster identifiziert werden, die nun dabei helfen können, das Verständnis über die Struktur- und Wirkungszusammenhänge zu erhöhen. An den beiden Schreckreaktionen konnte die unterschiedliche Wirkung von Anästhetika auf Phänokopien von genetisch veränderten Zebrabärblingen nachgewiesen werden, was die Einsatzfähigkeit für chemische sowie genetische Versuche substantiiert

Wearable Technology For Healthcare And Athletic Performance

Wearable technology research has led to advancements in healthcare and athletic performance. Devices range from one size fits all fitness trackers to custom fitted devices with tailored algorithms. Because these devices are comfortable, discrete, and pervasive in everyday life, custom solutions can be created to fit an individual\u27s specific needs. In this dissertation, we design wearable sensors, develop features and algorithms, and create intelligent feedback systems that promote the advancement of healthcare and athletic performance. First, we present Magneto: a body mounted electromagnet-based sensing system for joint motion analysis. Joint motion analysis facilitates research into injury prevention, rehabilitation, and activity monitoring. Sensors used in such analysis must be unobtrusive, accurate, and capable of monitoring fast-paced dynamic motions. Our system is wireless, has a high sampling rate, and is unaffected by outside magnetic noise. Magnetic noise commonly influences magnetic field readings via magnetic interference from the Earth\u27s magnetic field, the environment, and nearby ferrous objects. Magneto uses the combination of an electromagnet and magnetometer to remove environmental interference from a magnetic field reading. We evaluated this sensing method to show its performance when removing the interference in three movement dimensions, in six environments, and with six different sampling rates. Then, we localized the electromagnet with respect to the magnetic field reader, allowing us to apply Magneto in two pilot studies: measuring elbow angles and calculating shoulder positions. We calculated elbow angles to the nearest 15â—¦ with 93.8% accuracy, shoulder position in two-degrees of freedom with 96.9% accuracy, and shoulder positions in three-degrees of freedom with 75.8% accuracy. Second, we present TracKnee: a sensing knee sleeve designed and fabricated to unobtrusively measure knee angles using conductive fabric sensors. We propose three models that can be used in succession to calculate knee angles from voltage. These models take an input of voltage, calculate the resistance of our conductive fabric sensor, then calculate the change in length across the front of the knee and finally to the angle of the knee. We evaluated our models and our device by conducting a user study with six participants where we collected 240 ground truth angles and sensor data from our TracKnee device. Our results show that our model is 94.86% accurate to the nearest 15th degree angle and that our average error per angle is error per angle is 3.69 degrees. Third, we present ServesUp: a sensing shirt designed to monitor shoulder and elbow motion during the volleyball serve. In this project, we will designed and fabricated a sensing shirt that is comfortable, unobtrusive, and washable that an athlete can wear during and without impeding volleyball play. To make the shirt comfortable, we used soft and flexible conductive fabric sensors to monitor the motion of the shoulder and the elbow. We conducted a user study with ten volleyball players for a total of 1000 volleyball serves. We classified serving motion using a KNN with a classification accuracy of 89.2%. We will use this data provide actionable insights back to the player to help improve their serving skill. Fourth, we present BreathEZ, the first smartwatch application that provides both choking first aid instruction and real-time tactile and visual feedback on the quality of the abdominal thrust compressions. We evaluated our application through two user studies involving 20 subjects and 200 abdominal thrust events. The results of our study show that BreathEZ achieves a classification accuracy of 90.9% for abdominal thrusts. All participants that used BreathEZ in our study were able to improve their performance of abdominal thrusts. Of these participants, 60% were able to perform within the recommended range with the use of BreathEZ. Comparatively no participants trained with a video only reached that range. Finally, we present BBAid: the first smartwatch based system that provides real-time feedback on the back blow portion of choking first aid while instructing the user on first aid procedure. We evaluated our application through two user studies involving 26 subjects and 260 back blow events. The results of our study show that BBAid achieves a classification accuracy of 93.75% for back blows. With the use of BBAid, participants in our study were able to perform back blows within the recommended range 75% of the time. Comparatively the participants trained with a video only reached that range 12% of the time. All participants in the study, after receiving training were much more willing to perform choking first aid

Micro- and Nanofluidics for Bionanoparticle Analysis

Bionanoparticles such as microorganisms and exosomes are recoganized as important targets for clinical applications, food safety, and environmental monitoring. Other nanoscale biological particles, includeing liposomes, micelles, and functionalized polymeric particles are widely used in nanomedicines. The recent deveopment of microfluidic and nanofluidic technologies has enabled the separation and anslysis of these species in a lab-on-a-chip platform, while there are still many challenges to address before these analytical tools can be adopted in practice. For example, the complex matrices within which these species reside in create a high background for their detection. Their small dimension and often low concentration demand creative strategies to amplify the sensing signal and enhance the detection speed. This Special Issue aims to recruit recent discoveries and developments of micro- and nanofluidic strategies for the processing and analysis of biological nanoparticles. The collection of papers will hopefully bring out more innovative ideas and fundamental insights to overcome the hurdles faced in the separation and detection of bionanoparticles

Design, Construction and Validation of a New Generation of Bioreactors for Tissue Engineering Applications.

132 p.The thesis reports on the design, fabrication and validation of a new generation of bioreactors for cell culture stimulation, in order to improve cell proliferation in advanced tissue engineering strategies. Bioreactors are developed to take advantage of responsive materials allowing to mimic cell microenvironments, resembling some of the most common physical stimuli within the human body. Some stimuli can be produced by polymer-based scaffolds such as magnetoelectric, which can work as mechanical and electrical actuators.Two types of bioreactors were developed: one for bone tissue engineering through magnetoelectric stimulation (through mechanical vibration and piezoelectricity) and another for muscle tissue engineering through mechanical stretching and controlled current impulses.This project encompasses several fields of engineering such as device engineering, design, mechanics and electronics, having also into account proper material selection and the final biomedical application

Embroidered textile connectors for wearable systems

This thesis presents a novel textile microwave interconnect that can be easily attached and removed from textile devices. Interconnects perform a vital role in carrying RF signals between an amplifier and an antenna or other devices. Conventional interconnects used for interconnecting non-flexible circuits perform this function with very low losses, however the same is not true for transmission lines made on fabrics using conductive threads or inks. This scenario of using interconnects on fabric systems is challenging. Due to the necessity of washing fabrics, permanent attachments on the fabric have disadvantages. Theconnectionpresentedinthisthesisisdonewithoutanymetalor rigid parts on the textile devices side. The connector is held in place by magnets which are shown to have no negative impact on the microwave connection. Two models are then explored, a microstrip connector and a grounded coplanar waveguide (CPW) connector. A detailed study of the models was done and it was found that both models have reasonable results up to2GHz. The interconnects are fully characterized by de-embedding the connection part. This can be used to predict the effect the interconnect will have when used to connect a microwave equipment. The microstrip version of the interconnect is attached to an antenna and the results presented. The interconnect has no negative effect on the reflection coefficient measurement of the antenna. Repeatability tests were also performed with this model, with no visible change in the connection quality between measurements. Different embroidery patterns and stitching designs were also investigated. These are used to reduce the amount of conductive thread used up to 59% reduction in thread ammount. A wearable antenna was fully converted from rigid copper sheet to a full textile design

Haptics: Science, Technology, Applications

This open access book constitutes the proceedings of the 13th International Conference on Human Haptic Sensing and Touch Enabled Computer Applications, EuroHaptics 2022, held in Hamburg, Germany, in May 2022. The 36 regular papers included in this book were carefully reviewed and selected from 129 submissions. They were organized in topical sections as follows: haptic science; haptic technology; and haptic applications

Physical Diagnosis and Rehabilitation Technologies

The book focuses on the diagnosis, evaluation, and assistance of gait disorders; all the papers have been contributed by research groups related to assistive robotics, instrumentations, and augmentative devices