TY - THES A1 - Lopes, Pedro T1 - Interactive Systems Based on Electrical Muscle Stimulation N2 - How can interactive devices connect with users in the most immediate and intimate way? This question has driven interactive computing for decades. Throughout the last decades, we witnessed how mobile devices moved computing into users’ pockets, and recently, wearables put computing in constant physical contact with the user’s skin. In both cases moving the devices closer to users allowed devices to sense more of the user, and thus act more personal. The main question that drives our research is: what is the next logical step? Some researchers argue that the next generation of interactive devices will move past the user’s skin and be directly implanted inside the user’s body. This has already happened in that we have pacemakers, insulin pumps, etc. However, we argue that what we see is not devices moving towards the inside of the user’s body, but rather towards the body’s biological “interface” they need to address in order to perform their function. To implement our vision, we created a set of devices that intentionally borrow parts of the user’s body for input and output, rather than adding more technology to the body. In this dissertation we present one specific flavor of such devices, i.e., devices that borrow the user’s muscles. We engineered I/O devices that interact with the user by reading and controlling muscle activity. To achieve the latter, our devices are based on medical-grade signal generators and electrodes attached to the user’s skin that send electrical impulses to the user’s muscles; these impulses then cause the user’s muscles to contract. While electrical muscle stimulation (EMS) devices have been used to regenerate lost motor functions in rehabilitation medicine since the 1960s, in this dissertation, we propose a new perspective: EMS as a means for creating interactive systems. We start by presenting seven prototypes of interactive devices that we have created to illustrate several benefits of EMS. These devices form two main categories: (1) Devices that allow users eyes-free access to information by means of their proprioceptive sense, such as the value of a variable in a computer system, a tool, or a plot; (2) Devices that increase immersion in virtual reality by simulating large forces, such as wind, physical impact, or walls and heavy objects. Then, we analyze the potential of EMS to build interactive systems that miniaturize well and discuss how they leverage our proprioceptive sense as an I/O modality. We proceed by laying out the benefits and disadvantages of both EMS and mechanical haptic devices, such as exoskeletons. We conclude by sketching an outline for future research on EMS by listing open technical, ethical and philosophical questions that we left unanswered. N2 - Wie können interaktive Geräte auf unmittelbare und eng verknüpfte Weise mit dem Nutzer kommunizieren? Diese Frage beschäftigt die Forschung im Bereich Computer Interaktion seit Jahrzehnten. Besonders in den letzten Jahren haben wir miterlebt, wie Nutzer interaktive Geräte dauerhaft bei sich führen, im Falle von sogenannten Wearables sogar als Teil der Kleidung oder als Accessoires. In beiden Fällen sind die Geräte näher an den Nutzer gerückt, wodurch sie mehr Informationen vom Nutzer sammeln können und daher persönlicher erscheinen. Die Hauptfrage, die unsere Forschung antreibt, ist: Was ist der nächste logische Schritt in der Entwicklung interaktiver Geräte? Mache Wissenschaftler argumentieren, dass die Haut nicht mehr die Barriere für die nächste Generation von interaktiven Geräten sein wird, sondern dass diese direkt in den Körper der Nutzer implantiert werden. Zum Teil ist dies auch bereits passiert, wie Herzschrittmacher oder Insulinpumpen zeigen. Wir argumentieren jedoch, dass Geräte sich in Zukunft nicht zwingend innerhalb des Körpers befinden müssen, sondern sich an der richtigen „Schnittstelle“ befinden sollen, um die Funktion des Gerätes zu ermöglichen. Um diese Entwicklung voranzutreiben haben wir Geräte entwickelt, die Teile des Körpers selbst als Ein- und Ausgabe-Schnittstelle verwenden, anstatt weitere Geräte an den Körper anzubringen. In dieser Dissertation zeigen wir eine bestimmte Art dieser Geräte, nämlich solche, die Muskeln verwenden. Wir haben Ein-/Ausgabegeräte gebaut, die mit dem Nutzer interagieren indem sie Muskelaktivität erkennen und kontrollieren. Um Muskelaktivität zu kontrollieren benutzen wir Signalgeber von medizinischer Qualität, die mithilfe von auf die Haut geklebten Elektroden elektrische Signale an die Muskeln des Nutzers senden. Diese Signale bewirken dann eine Kontraktion des Muskels. Geräte zur elektrischen Muskelstimulation (EMS) werden seit den 1960er-Jahren zur Regeneration von motorischen Funktionen verwendet. In dieser Dissertation schlagen wir jedoch einen neuen Ansatz vor: elektrische Muskelstimulation als Kommunikationskanal zwischen Mensch und interaktiven Computersysteme. Zunächst stellen wir unsere sieben interaktiven Prototypen vor, welche die zahlreichen Vorteile von EMS demonstrieren. Diese Geräte können in zwei Hauptkategorien unterteilt werden: (1) Geräte, die Nutzern Zugang zu Information direkt über ihre propriozeptive Wahrnehmung geben ohne einen visuellen Reiz. Diese Informationen können zum Beispiel Variablen, Diagramme oder die Handhabung von Werkzeugen beinhalten. (2) Des Weiteren zeigen wir Geräte, welche die Immersion in virtuelle Umgebungen erhöhen indem sie physikalische Kräfte wie Wind, physischen Kontakt, Wände oder schwere Objekte, simulieren. Wir analysieren in dieser Arbeit außerdem das Potential von EMS für miniaturisierte interaktive Systeme und diskutieren, wie solche EMS Systeme die propriozeptive Wahrnehmung wirksam als Ein-/Ausgabemodalität nutzen können. Dazu stellen wir die Vor- und Nachteile von EMS und mechanisch-haptischen Geräten, wie zum Beispiel Exoskeletten, gegenüber. Zum Abschluss skizzieren wir zukünftige Richtungen in der Erforschung von interaktiven EMS Systemen, indem wir bislang offen gebliebene technische, ethische und philosophische Fragen aufzeigen. KW - electrical muscle stimulation KW - wearables KW - virtual reality KW - Wearable KW - elektrische Muskelstimulation KW - virtuelle Realität Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-421165 ER - TY - JOUR A1 - Limanowski, Jakub A1 - Lopes, Pedro A1 - Keck, Janis A1 - Baudisch, Patrick A1 - Friston, Karl A1 - Blankenburg, Felix T1 - Action-dependent processing of touch in the human parietal operculum and posterior insula JF - Cerebral Cortex N2 - Somatosensory input generated by one's actions (i.e., self-initiated body movements) is generally attenuated. Conversely, externally caused somatosensory input is enhanced, for example, during active touch and the haptic exploration of objects. Here, we used functional magnetic resonance imaging (fMRI) to ask how the brain accomplishes this delicate weighting of self-generated versus externally caused somatosensory components. Finger movements were either self-generated by our participants or induced by functional electrical stimulation (FES) of the same muscles. During half of the trials, electrotactile impulses were administered when the (actively or passively) moving finger reached a predefined flexion threshold. fMRI revealed an interaction effect in the contralateral posterior insular cortex (pIC), which responded more strongly to touch during self-generated than during FES-induced movements. A network analysis via dynamic causal modeling revealed that connectivity from the secondary somatosensory cortex via the pIC to the supplementary motor area was generally attenuated during self-generated relative to FES-induced movements-yet specifically enhanced by touch received during self-generated, but not FES-induced movements. Together, these results suggest a crucial role of the parietal operculum and the posterior insula in differentiating self-generated from externally caused somatosensory information received from one's moving limb. KW - active touch KW - dynamic causal modeling KW - insula KW - parietal operculum KW - somatosensation Y1 - 2019 U6 - https://doi.org/10.1093/cercor/bhz111 SN - 1047-3211 SN - 1460-2199 VL - 30 IS - 2 SP - 607 EP - 617 PB - Oxford University Press CY - Oxford ER - TY - GEN A1 - Kovacs, Robert A1 - Ion, Alexandra A1 - Lopes, Pedro A1 - Oesterreich, Tim A1 - Filter, Johannes A1 - Otto, Philip A1 - Arndt, Tobias A1 - Ring, Nico A1 - Witte, Melvin A1 - Synytsia, Anton A1 - Baudisch, Patrick T1 - TrussFormer BT - 3D Printing Large Kinetic Structures T2 - The 31st Annual ACM Symposium on User Interface Software and Technology N2 - We present TrussFormer, an integrated end-to-end system that allows users to 3D print large-scale kinetic structures, i.e., structures that involve motion and deal with dynamic forces. TrussFormer builds on TrussFab, from which it inherits the ability to create static large-scale truss structures from 3D printed connectors and PET bottles. TrussFormer adds movement to these structures by placing linear actuators into them: either manually, wrapped in reusable components called assets, or by demonstrating the intended movement. TrussFormer verifies that the resulting structure is mechanically sound and will withstand the dynamic forces resulting from the motion. To fabricate the design, TrussFormer generates the underlying hinge system that can be printed on standard desktop 3D printers. We demonstrate TrussFormer with several example objects, including a 6-legged walking robot and a 4m-tall animatronics dinosaur with 5 degrees of freedom. KW - fabrication KW - 3D printing KW - variable geometry truss KW - large-scale mechanism Y1 - 2019 SN - 978-1-4503-5971-9 U6 - https://doi.org/10.1145/3290607.3311766 PB - Association for Computing Machinery CY - New York ER - TY - GEN A1 - Kovacs, Robert A1 - Ion, Alexandra A1 - Lopes, Pedro A1 - Oesterreich, Tim A1 - Filter, Johannes A1 - Otto, Philip A1 - Arndt, Tobias A1 - Ring, Nico A1 - Witte, Melvin A1 - Synytsia, Anton A1 - Baudisch, Patrick T1 - TrussFormer BT - 3D Printing Large Kinetic Structures T2 - UIST '18: Proceedings of the 31st Annual ACM Symposium on User Interface Software and Technology N2 - We present TrussFormer, an integrated end-to-end system that allows users to 3D print large-scale kinetic structures, i.e., structures that involve motion and deal with dynamic forces. TrussFormer builds on TrussFab, from which it inherits the ability to create static large-scale truss structures from 3D printed connectors and PET bottles. TrussFormer adds movement to these structures by placing linear actuators into them: either manually, wrapped in reusable components called assets, or by demonstrating the intended movement. TrussFormer verifies that the resulting structure is mechanically sound and will withstand the dynamic forces resulting from the motion. To fabricate the design, TrussFormer generates the underlying hinge system that can be printed on standard desktop 3D printers. We demonstrate TrussFormer with several example objects, including a 6-legged walking robot and a 4m-tall animatronics dinosaur with 5 degrees of freedom. KW - Fabrication KW - 3D printing KW - variable geometry truss KW - large scale mechanism Y1 - 2018 SN - 978-1-4503-5948-1 U6 - https://doi.org/10.1145/3242587.3242607 SP - 113 EP - 125 PB - Association for Computing Machinery CY - New York ER -