Supporting Eyes-Free Human–Computer Interaction with Vibrotactile Haptification

The sense of touch is a crucial sense when using our hands in complex tasks. Some tasks we learn to do even without sight by just using the sense of touch in our fingers and hands. Modern touchscreen devices, however, have lost some of that tactile feeling while removing physical controls from the interaction. Touch is also a sense that is underutilized in interactions with technology and could provide new ways of interaction to support users. While users are using information technology in certain situations, they cannot visually and mentally focus completely during the interaction. Humans can utilize their sense of touch more comprehensively in interactions and learn to understand tactile information while interacting with information technology. This thesis introduces a set of experiments that evaluate human capabilities to understand and notice tactile information provided by current actuator technology and further introduces a couple of examples of haptic user interfaces (HUIs) to use under eyes-free use scenarios. These experiments evaluate the benefits of such interfaces for users and concludes with some guidelines and methods for how to create this kind of user interfaces. The experiments in this thesis can be divided into three groups. In the first group, with the first two experiments, the detection of vibrotactile stimuli and interpretation of the abstract meaning of vibrotactile feedback was evaluated. Experiments in the second group evaluated how to design rhythmic vibrotactile tactons to be basic vibrotactile primitives for HUIs. The last group of two experiments evaluated how these HUIs benefit the users in the distracted and eyes-free interaction scenarios. The primary aim for this series of experiments was to evaluate if utilizing the current level of actuation technology could be used more comprehensively than in current-day solutions with simple haptic alerts and notifications. Thus, to find out if the comprehensive use of vibrotactile feedback in interactions would provide additional benefits for the users, compared to the current level of haptic interaction methods and nonhaptic interaction methods. The main finding of this research is that while using more comprehensive HUIs in eyes-free distracted-use scenarios, such as while driving a car, the user’s main task, driving, is performed better. Furthermore, users liked the comprehensively haptified user interfaces

Tactile Arrays for Virtual Textures

This thesis describes the development of three new tactile stimulators for active touch, i.e. devices to deliver virtual touch stimuli to the fingertip in response to exploratory movements by the user. All three stimulators are designed to provide spatiotemporal patterns of mechanical input to the skin via an array of contactors, each under individual computer control. Drive mechanisms are based on piezoelectric bimorphs in a cantilever geometry. The first of these is a 25-contactor array (5 × 5 contactors at 2 mm spacing). It is a rugged design with a compact drive system and is capable of producing strong stimuli when running from low voltage supplies. Combined with a PC mouse, it can be used for active exploration tasks. Pilot studies were performed which demonstrated that subjects could successfully use the device for discrimination of line orientation, simple shape identification and line following tasks. A 24-contactor stimulator (6 × 4 contactors at 2 mm spacing) with improved bandwidth was then developed. This features control electronics designed to transmit arbitrary waveforms to each channel (generated on-the-fly, in real time) and software for rapid development of experiments. It is built around a graphics tablet, giving high precision position capability over a large 2D workspace. Experiments using two-component stimuli (components at 40 Hz and 320 Hz) indicate that spectral balance within active stimuli is discriminable independent of overall intensity, and that the spatial variation (texture) within the target is easier to detect at 320 Hz that at 40 Hz. The third system developed (again 6 × 4 contactors at 2 mm spacing) was a lightweight modular stimulator developed for fingertip and thumb grasping tasks; furthermore it was integrated with force-feedback on each digit and a complex graphical display, forming a multi-modal Virtual Reality device for the display of virtual textiles. It is capable of broadband stimulation with real-time generated outputs derived from a physical model of the fabric surface. In an evaluation study, virtual textiles generated from physical measurements of real textiles were ranked in categories reflecting key mechanical and textural properties. The results were compared with a similar study performed on the real fabrics from which the virtual textiles had been derived. There was good agreement between the ratings of the virtual textiles and the real textiles, indicating that the virtual textiles are a good representation of the real textiles and that the system is delivering appropriate cues to the user

Hair follicle dermal cells: a morphological, behavioural and molecular study

Anatomy and smooth muscle a-actin expression in hair follicles from a variety of animal species (Mink, Polecat, Meerkat, Grey squirrel and stoat) was investigated. Smooth muscle ɑ-actin expression was related to follicle activity. Expression was greatest during anagen, with a marked reduction in expression during telogen. Follicular dermal cells were cultured from the above animal species. In vitro grey squirrel dermal papilla (DP) and dermal sheath (DS) cells both expressed smooth muscle ɑ -actin. Rat dermal papilla cell in vitro aggregative behaviour was characterized, by proliferation, chemotactic and molecular studies. Aggregation behaviour in these cells was not attributed to focal proliferation. However, fluctuations in cell motility correlated with the aggregation process, with the greatest motility between subconfluent and clumped cells. Motility was terminated within the clumped cells. Furthermore, DP cells in vitro secreted molecules that enhancer! motility in subconfluent DP cells and a variety of other cell types. As yet the type and specificity of this medium borne component is unknown. TGFP, bFGF and aFGF were all used as a comparison to the unknown molecule, however migration was rarely similar in magnitude to the response of the DP cell medium. Mouse cDNA probes of BMP 2 and BMP 4 were used to isolate rat homologues from a cDNA library. Wholemount in situ hybridization of BMP 4 expression was consistent with the data in the mouse, however BMP 4 was also expressed in adult rat telogen vibrissae. Molecular expression within in vitro DP cells was studied using a differential screen of a cDNA library. A number of clumped DP specific clones were differentially expressed, one of which having high homology with migration inhibitory factor. These results are discussed, and a hypothetical model is proposed to describe how DP aggregation occurs with reference to dermal condensation in vivo

触覚フィードバックを用いた体性感覚の操作

人間が自らの肉体に対して持つ興味は大きい．多くの人間は体力的・知能的・美的な面で他の人間よりも優れた肉体を欲すると考えられ，また様々な特殊な体を持つ空想上のキャラクターに憧れ人間とは異なる構造の身体に興味を持つ物も多いであろう．だが身体機能の向上のためには通常長期間の継続した訓練を必要とし，人間とは異なる身体への変身は不可能であるといえる．科学技術の発展に伴い肉体形状および運動機能への物理的な介入方法が広まりつつあるが，未だに身体的リスクと金銭的コストが高く，複雑な装置を必要とするため誰もが気軽に利用できるものではない．このような背景から本研究では，人間の肉体そのものに介入するのではなく，肉体が生成する感覚である体性感覚を肉体外部から操作することで肉体の主観的特性を操作することを目標とする．主に身体表面の感覚を刺激するアクチュエータとして広く使われているボイスコイル型振動子は，様々な触感の呈示を簡便なセットアップで実現できる．したがってこれを身体運動に同期させて駆動する振動フィードバックシステムを開発し，運動に伴って発生する身体内部の感覚を操作することを試みる．体性感覚の操作に関する本研究は2 つの戦略によって構成される．一つは体性感覚の「増強」である．これは自己身体運動を把握する能力を高め，より鮮明に，あるいは詳細に運動状態を知覚させる量的な操作である．一方で，もう一つの戦略は体性感覚の質的な操作である「変調」である．これは身体自体の硬さや重さといった特性を変化させることであり，結果として身体を構成する材質・構造を主観的に変調することになる．これら2 つの戦略に沿った具体的な手法を，体性感覚の増強に関して2 件，変調に関しても2件設計した．体性感覚の増強に関しては，第一にロータリスイッチの回転に伴うカチカチとした触覚・力覚フィードバック「カチカチ感」に着目した．これを肘関節に付与して運動時の体性感覚を鮮明化し，腕立て伏せ姿勢の教示を試みた（第3 章）．第二に，自動車運転におけるアクセルペダルの操作を補助するため，ペダルの角度が一定値変化する度に瞬間的なクリック振動を呈示することで，ペダル角度の把握能力向上および操作性向上を試みた（第4 章）．体性感覚の変調に関しては，第一に様々な材質の衝突振動を再現する減衰正弦波モデルに着目し，これを身体運動に同期させて呈示することで身体材質感の変調を試みた（第5 章）．これによりロボットやゴム人間といった特殊なキャラクターの体性感覚の再現を目指した．第二に，ロボットキャラクターのみに着目し，実際のロボットに生じる振動加速度を記録・モデリング・再生する手法によりロボットの内部構造に起因する体性感覚まで再現することを試みた（第6 章）．またロボット感体験の総合的なリアリティ向上のため高品質な視覚・聴覚刺激を組み合わせたバーチャルリアリティゲームを開発した．また体性感覚の操作をより広範囲で行うため，既存の触覚ディスプレイの問題点を考察し，身体広範囲に均等な触覚刺激を呈示する触覚ディスプレイを開発した（第7 章）．最後に本研究全体のまとめと結論を述べ，今後の展望を示す（第8 章）．電気通信大学201

Three Dimensional (3D) Printable Gel-Inks for Skin Tissue Regeneration

Recent and rapid progression in three-dimensional (3D) printing techniques has revolutionized conventional therapies in medicine; 3D printed constructs are gradually being recognized as common substitutes for the replacement of skin wounds. As gel-inks, large numbers of natural and synthetic (e.g., collagen and polyurethane, respectively) substances were used to be printed into different shapes and sizes for managing both acute and chronic skin wounds. The resultant 3D printed scaffolds not only provide physical support but also act as supporting niches for improving immunomodulation and vascularization and subsequent accelerated wound healing. Recently, the use of thermosensitive and pH-responsive gels has made it possible to prepare 3D printed constructs with the ability to facilitate in situ crosslinking within the biopolymer and with native wound edge tissue as well as to fill the exact shape of wound damage. In this chapter, we aim to introduce the current state of 3D printable gel-inks utilized for skin wound treatment and illustrate future prospects in this amazing area of science

Peripheral Neuropathy

Understanding the rapid changes in the evaluation and management of peripheral neuropathies, as well as the complexity of their mechanism, is a mandatory requirement for the practitioner to optimize patient's care. The objective of this book is to update health care professionals on recent advances in the pathogenesis, diagnosis and treatment of peripheral neuropathy. This work was written by a group of clinicians and scientists with large expertise in the field

Pollination ecology and the functional significance of unusual floral traits in two South African stapeliads.

Master of Science in Ecology. University of KwaZulu-Natal, Durban 2017.Carrion and dung mimicking plants often exhibit unusual floral traits which are believed to attract necro- and coprophagous insects as pollinators. Our understanding of these unusual traits and their functions is very limited. Stapeliads (Apocynaceae: Asclepiadoideae: Stapeliinae) are a monophyletic group of some 400 species of stem-succulent plants, many of which emit foul odours and exhibit unusual morphological traits that have anecdotally been assumed to represent adaptations to enhance the flowers’ resemblance to carrion or dung. This study looked at the pollination biology of two stapeliads, Orbea variegata and Stapelia hirsuta var. hirsuta, and explored the functional significance of some of the floral traits commonly associated with carrion or dung mimicking flowers. Further, odours emitted by both species were compared to the odours of putative models to explore the chemical basis for the assumed mimicry. Orbea variegata attracted flies from the families Muscidae, Calliphoridae and Sarcophagidae (at sites near Scarborough and Clifton, Western Cape) and individuals from each of these families were found carrying pollinia. The scent of O. variegata flowers was found to be dominated by dimethyl disulphide, dimethyl trisulphide as well as phenol. The presence of both these compounds suggests mimicry of both carrion and dung, although an ANOSIM analysis indicated that the odour of O. variegata shared more similarities with dung. This suggests that O. variegata is fairly generalist and explains the attraction of various flies that are associated with carrion or faeces by the flowers of this species. In experiments testing the importance of black versus yellow colouring and the importance of patterning, flies were found to prefer black coloured models in the presence of O. variegata odour, whereas the presence and size of blotching on the corolla lobes had no significant effect on fly visits. The colours of the black blotching and yellow of the corolla lobes showed minimal chromatic contrast when interpreted using the Troje (1993) fly vision model, although background rocks showed chromatic contrast, suggesting flies can distinguish between the flowers and the background. In an experiment testing the importance of odour for attracting flies, significantly fewer flies were able to locate concealed flowers compared to visible flowers, suggesting an important role for visual cues for flies to locate the odour source. Stapelia hirsuta var. hirsuta was found to exhibit two floral colour morphs at Swellendam (Western Cape). The yellow morph was rarer than the maroon morph. These flowers attracted flies belonging to the Muscidae, Calliphoridae and Sarcophagidae families, although only Calliphoridae and Sarcophagidae were found to carry pollinia. The odour composition of these two morphs differed slightly, where the odour of the maroon morph was dominated by dimethyl disulphide, dimethyl trisulphide and p-cresol and the yellow morph was dominated by dimethyl disulphide, dimethyl trisulphide and limonene. The ANOSIM analysis of odours emitted by S. hirsuta var. hirsuta in relation to that of various fly oviposition substrates suggested that these flowers are dung mimics rather than carrion mimics, although the presence of sulphides suggests possible mimicry of both. The yellow morph had higher fly visitation rates than the maroon morph. In experiments testing the role of floral trichomes, the removal of floral trichomes significantly decreased the visitation rates to the flowers, as well as the amount of time visitors spend on the flowers. Again, visual cues were shown to be of importance, as visible flowers received more visits than concealed flowers. Analysis of colours of different floral morphs, using the Troje (1993) fly vision model, suggests that flies cannot perceive chromatic colour differences between morphs. In these studies, I have shown that O. variegata and S. hirsuta var. hirsuta are visited and pollinated by carrion associated flies, and the flowers emit odours associated with both carrion and dung. This work sheds light on some of the floral features that are often associated with carrion and dung mimicry by flowers and the roles they play in the attraction of flies

Electrotactile feedback applications for hand and arm interactions: A systematic review, meta-analysis, and future directions

Haptic feedback is critical in a broad range of human-machine/computer-interaction applications. However, the high cost and low portability/wearability of haptic devices remain unresolved issues, severely limiting the adoption of this otherwise promising technology. Electrotactile interfaces have the advantage of being more portable and wearable due to their reduced actuators' size, as well as their lower power consumption and manufacturing cost. The applications of electrotactile feedback have been explored in human-computer interaction and human-machine-interaction for facilitating hand-based interactions in applications such as prosthetics, virtual reality, robotic teleoperation, surface haptics, portable devices, and rehabilitation. This paper presents a technological overview of electrotactile feedback, as well a systematic review and meta-analysis of its applications for hand-based interactions. We discuss the different electrotactile systems according to the type of application. We also discuss over a quantitative congregation of the findings, to offer a high-level overview into the state-of-art and suggest future directions. Electrotactile feedback systems showed increased portability/wearability, and they were successful in rendering and/or augmenting most tactile sensations, eliciting perceptual processes, and improving performance in many scenarios. However, knowledge gaps (e.g., embodiment), technical (e.g., recurrent calibration, electrodes' durability) and methodological (e.g., sample size) drawbacks were detected, which should be addressed in future studies.Comment: 18 pages, 1 table, 8 figures, under review in Transactions on Haptics. This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessible.Upon acceptance of the article by IEEE, the preprint article will be replaced with the accepted versio

Influence des facteurs neurotrophiques et des fibres nerveuses dans la peau reconstruite par génie tissulaire

Tableau d’honneur de la Faculté des études supérieures et postdoctorales, 2013-2014.La peau est un organe densément innervé et vascularisé. L’établissement du réseau nerveux dépend de la sécrétion de signaux diffusibles dans la peau qui instruisent à distance certains neurones de s’y arboriser. Ces signaux sont les facteurs neurotrophiques. L’établissement du réseau vasculaire dépend aussi de la présence de signaux instructifs. Notre objectif général était de mieux comprendre l’influence des signaux neurotrophiques et aussi nerveux dans le contexte cutané. Les travaux présentés dans cette thèse décrivent de nouvelles interactions paracrines. Alors que certaines de ces interactions depuis la peau vers les neurones sensoriels et certaines depuis les neurones sensoriels vers le réseau vasculaire pour la vasodilatation sont déjà établies, nous décrivons l’influence des facteurs neurotrophiques sur le réseau vasculaire et l’influence des neurones sensoriels sur la réépithélialisation. Nous avons premièrement émis l’hypothèse qu’en plus d’influencer les neurones, les facteurs neurotrophiques influencent le réseau vasculaire. Nous montrons que le NGF, le BDNF, le NT-3 et le GDNF sont tous exprimés dans l'épiderme, que le NGF et le NT-3 sont exprimés par les fibroblastes et que le BDNF est produit par les cellules endothéliales. Les cellules de Schwann, également retrouvées dans la peau, produisent du NGF, BDNF et GDNF. Nous montrons que ces peptides sont de très puissants facteurs angiogéniques en utilisant un modèle de derme endothélialisé humain reconstruit par génie tissulaire. Une augmentation de 40 à 80 % du nombre de pseudocapillaires fut observée après l'addition de 10 ng/ml de NGF, 0,1 ng/ml de BDNF, 15 ng/ml de NT-3, et 50 ng/ml de GDNF. Cet effet angiogénique dépend de la liaison aux récepteurs de facteurs neurotrophiques TrkA, TrkB, GFRa-1 et c-ret, qui sont tous exprimés par les cellules endothéliales humaines. Cet effet a été bloqué pour les récepteurs Trk par l’addition de l'inhibiteur compétitif K252a. Ensuite, nous avons dans un deuxième temps émis l’hypothèse que les neurones sensoriels influencent directement la réépithélialisation. Pour vérifier cela, nous avons développé un nouveau modèle de réépithélialisation par génie tissulaire. Il est constitué d’un équivalent épidermique troué exprimant une protéine fluorescente verte qui a été empilé sur un équivalent dermique servant de substrat pour l’épiderme qui referme alors naturellement la plaie. L’équivalent est endothélialisé et innervé ou non par les neurones sensoriels de souris. Nous avons observé que la réépithélialisation est plus rapide en présence de neurones sensoriels. Nous avons démontré que les neurones sensoriels sécrètent une petite protéine dans notre modèle, soit de la substance P, et que les kératinocytes expriment le récepteur cellulaire NK1 de la substance P. Enfin, nous montrons que la substance P contribue à augmenter la vitesse de fermeture des plaies induites par les neurones à l'aide d’un agoniste et d’un antagoniste du récepteur NK1. L'ensemble des résultats procure une meilleure compréhension de l’importance des contextes neurotrophiques et nerveux dans la peau. Nos résultats pourraient laisser présager que d’améliorer la régénération nerveuse cutanée lorsqu’elle est déficiente améliorerait aussi l’homéostasie du tissu cutané.The skin is an organ densely innervated and vascularized. The establishment of the cutaneous nervous system depends on the secretion of neurotrophic factors by the skin. Meanwhile, the establishment of the vascular network also depends on soluble instructive cues. The work presented in this thesis describes new paracrine interactions. While interactions from skin to sensory neurons for the development of innervation and interactions from sensory neurons to blood vessel for vasodilation of the vasculature are described elsewhere, we demonstrate here the influence of neurotrophic factors on the vascular network and the influence of sensory neurons on the reepithelialization of wounds. Our overall goal was to clarify the influence of the neurotrophic and nervous contexts on the homeostasis of the skin. First, we hypothesized that in addition to their neuronal contribution, neurotrophic factors also influence the vascular network. We show that NGF, BDNF, NT-3 and GDNF are expressed in the epidermis, while NGF and NT-3 are expressed by fibroblasts and BDNF by endothelial cells. Finally, Schwann cells produce NGF, BDNF and GDNF. We show that these peptides are very potent angiogenic factors using a model of human endothelialized reconstructed dermis by tissue engineering. An increase of 40 to 80% of the number of capillary-like tubes was observed after the addition of 10 ng/ml NGF, 0.1 ng/ml of BDNF, 15 ng/ml of NT-3, and 50 ng/ml of GDNF. This angiogenic effect depends on the neurotrophic factor receptor TrkA, TrkB, GFRa-1 and c-ret that are all expressed by human endothelial cells. This effect was blocked by adding the Trk inhibitor K252a for NGF, BDNF and NT-3. Second, we hypothesized that sensory neurons directly influence reepithelialization by secreting the neuropeptide substance P. To verify this, we developed a new model of reepithelialization. It consists of a perforated epidermal equivalent expressing a green fluorescent protein stacked on a dermal equivalent that is used as a bed for reepithelialization. The reconstructed skin is endothelialized and innervated or not with sensory neurons of mouse. Sensory neurons produce substance P in the model and keratinocytes express the NK1 cell receptor for substance P. Keratinocyte migration was quantified by fluorescence. Reepithelialization was faster in presence of sensory neurons and we show that substance P contributes to this effect with agonist and antagonist of the NK1 cell receptor. The overall results provide a better understanding of the importance of the neurotrophic and sensory contexts in the skin. Thus, cutaneous innervation does not only contribute to the sensory detection. Our findings may suggest that improving nerve regeneration would improve skin long term tissue homeostasis