Human-device Interface Research Articles

Self-powered, multifunctional, and skin-compatible electronic-tattoos based on hybrid bio-nanomaterials as electrically functionalized skins

Electronic tattoos (E-tattoos), imparting electrical functions to skin imperceptibly, are attractive for future biomedical engineering applications. However, it is still challenging to implement all requirements such as biocompatibility, skin-adhesion, breathability, self-powering, etc. in a single E-tattoo for a seamless human–device interface. Here, we report hybrid biomaterial-based E-tattoos fabricated by incorporating graphene with silk sericin (SS)-loaded cellulose nanofibers (CNFs), leveraging each other’s strengths for skin-compatible and multifunctional operations. Graphene/SS/CNF E-tattoos show stable and high electrical conductivities under mechanical deformations, along with breathability. Due to SS, strong skin-adhesion is possible without skin irritation. The broadband optical absorption and temperature-dependent conductivity of graphene facilitate optically and electrically stimulated heat patches and temperature sensors. Furthermore, skin-compatibility enables skin-activated self-powering operation via triboelectricity. A substantial open circuit voltage of 320 ± 20 V and power density of 7.2 mW/cm2, sufficient to turn-on light-emitting diodes, are achieved, and self-powered sensory systems can be developed owing to flexible and porous traits of the E-tattoo. The E-tattoo platform, serving as a proof of concept, demonstrates its utility in healthcare and secure communications by enabling Morse code transmission and biomechanical movement detection. This innovative hybrid biomaterial-based E-tattoo can significantly boost healthcare monitoring and secure communication.

Pathway to Developing Permeable Electronics.

Permeable electronics possess the capability of permeating gas and/or liquid while performing the device functionality when attached to human bodies. The permeability of wearable electronics can not only minimize the thermophysiological disturbance to the human body but also ensure a biocompatible human-device interface for long-term, continuous, and real-time health monitoring. To date, how to simultaneously acquire high permeability and multifunctionality is the major challenge of wearable electronics. Here, a critical discussion on the future development of wearable electronics toward permeability is presented. In this perspective, the critical metrics of permeable electronics are discussed, and the historical evolution of wearable technologies is reviewed with highlights of representative examples. The materials and structural strategies for developing high-performance permeable electronics are then analyzed.

Ultra stretchable, tough, elastic and transparent hydrogel skins integrated with intelligent sensing functions enabled by machine learning algorithms

Hydrogel-based ionic skins are ionic conductive artificial skin-like materials that are promising for a broad range of applications such as wearable sensory devices, soft robotics and machines, and bioelectronics. However, fabricating hydrogel skins with satisfying mechanical performance and intelligent sensing functions is still a significant challenge. Herein, we have developed an ionic conductive nanocomposite hydrogel with ultra stretchability and self-evolving sensing functions. By leveraging the dynamic feature of synergetic interfacial ionic interactions, a trace amount of carbon nanotubes endows the hydrogel networks with excellent mechanical performances (i.e., tensile strength, stretchability and toughness up to 1.09 MPa, 4075 % and 12.8 MJ/m3, respectively). Additionally, the hydrogel is soft, elastic, transparent and self-healing. The rational combination of the mechanical and electrical properties renders the as-prepared hydrogel with excellent sensing performances and cycling stability, and therefore enables it to perform as a sensory unit of a complete platform for the recognition of some complicated human behaviors, outperforming the previously reported hydrogels due to its intelligent sensing functions. Specifically, with the integration of machine learning module, the hydrogel-based platform exhibits great recognition accuracies to human handwriting motions from single letters to words, phrases, and short sentences after proper training. The combination of superior mechanical performances and self-evolving sensing functions within this hydrogel-based ionic skin unlocks its potential as the intelligent human-device interface, which promotes the application of artificial intelligence in customized electronic devices.

Wireless Remote Controlled Linear Actuator Lamp

Abstract: A radio frequency (RF) signal refers to a wireless electromagnetic signal used as a form of communication if one is discussing wireless electronics. Radio waves are a form of electromagnetic radiation with identified radio frequencies that range from 3kHz to 300 GHz. Any electronic device is termed sophisticated, regarding the magnitude of human-device interface and thus enhancing the need to control any device to enable optimum utilization in any application. The ability to control any device needs the help of an intermediate device which acts as a medium between the human and device. This project’s goal is to create a lamp which can move upwards and downwards using linear actuator and can be controlled remotely. Atmega328p Microcontroller which is an open-source hardware and software that designs and manufactures single board microcontroller kits for building digital devices and interactive objects that can sense and control both physically and digitally. Keywords: Radio frequency, Wireless/Remotely, Atmega328p, Linear actuator, Lamp, Human-Device Interface.

Becoming-Data, Becoming-Mountain

This article explores our ecological relation to both information and information technologies as we "mediate mountains." Starting with a Gibsonian approach to affordances, and considering how an agent-specific account of action limits human access to "the digital," I suggest that the interface between human and device marks a double-coupling of two agents—one digital the other embodied—each of which draws out the other to alter potential action. The essay explores the affordances of agents and the environments in which they act, and how action seemingly occurs across the boundaries marked by the human-device interface. Drawing on actor network theory, assemblage theory, and Don Ihde's "inter-relational ontology," I examine how, within an ecology of humans and mobile devices, "agency" and "action" operate within a Deleuzean transversal, cutting across body-machine boundaries. As an application of this analysis, I examine the relationship between embodied and digital agents "in the wild" of the mountains, through AR and GPS-enabled smartphone apps, and how each agent, acting upon its own environment, gives rise to transversal events that alter the affordances offered to agents across a seemingly uncrossable divide.

Soft multi-modal thermoelectric skin for dual functionality of underwater energy harvesting and thermoregulation

Sustaining a long-term but viable power source for underwater electronics has been an engineering conundrum due to a lack of feasible physical mechanisms to harvest energy in the underwater environment. In this regard, thermoelectricity, which converts heat into electricity, can suggest a potent solution, since the ocean and other water bodies maintain the constant water temperature and therefore serve as a permanent thermal differential. In addition to energy harvesting, the same thermoelectric device can be also utilized to both heat and cool, thereby providing an effective means of controlling the temperature of the arbitrary subject in the underwater environment. In this light, we present a soft and stretchable multi-modal thermoelectric skin (TES) that can both (i) generate electricity across the temperature differential between the ocean water and the human body and (ii) thermoregulate the body temperature in the underwater environment. The soft and elastic nature of TES enables an intimate and thorough contact with the deformable and irregular surfaces of the human skin, therefore maximizing the heat conduction at the human-device interface that the rigid or flexible thermoelectric devices can not fully attain. To the authors’ best knowledge, TES produces the highest electrical power density when compared to the stretchable thermoelectric devices reported so far, mainly owing to its optimum design factors. Along with the outstanding device performance, the underwater environment further boosts the thermoelectric efficiency of TES both in energy harvesting and thermoregulatory perspectives due to the much more favorable thermal properties of water than those of air. Furthermore, to verify the practical usage of TES and demonstrate its high wearability, we incorporated multiple TES units into the neoprene dry-suit. The TES units can self-power multiple embedded sensors that wirelessly monitor the physiological condition and further provide the spatial information of the tactical diver, such that the TES units and embedded system can function as a wearable underwater rescue platform. Lastly, the temperature feedback loop algorithm embedded in the thermoregulatory system allows the TES units to constantly regulate the temperature of the human body and thus prevent underwater hypo-/hyperthermia.

Mycena chlorophos-inspired autoluminescent triboelectric fiber for wearable energy harvesting, self-powered sensing, and as human–device interfaces

Wearable/stretchable electronics and e-textiles require power. Meanwhile, luminescence is an important functionality to wearables for illumination, energy saving, identification and manipulation in the dark, and safety during nocturnal activities. Triboelectric nanogenerators (TENGs) are promising power suppliers and self-powered sensors. However, the instant TENG electricity can only produce transient luminescence, and the energy required for luminescence consumes the energy reserved for other electronics. Inspired by bioluminescent Mycena chlorophos, a self-luminescing and energy-harvesting triboelectric fiber (SLEH-TF) is proposed as a wearable energy provider, self-powered sensor, and human–device interface. It comprises a conducting thread clad in an elastic phosphorescent triboelectric composite and can be knitted into a large-area highly stretchable (> 100% strain) textile for sustainably powering gadgets. It can convert biomechanical energy into available electricity (Voc = 15 V and Isc = 500 nA from a 5-cm SLEH-TF; Voc = 250 V and Isc = 80 μA from a palm-sized SLEH-TF textile) and simultaneously emit long-lasting visible light (50 mcd m−2 for > 120 min) after a short exposure to daylight (5 min). Furthermore, SLEH-TF can be used for detecting pressure (with sensitivity of 11.48 V N−1 and 119.54 nA N−1 (<1 N)), touch, and gestures via self-generating electricity. Finally, system-level smart clothes using the newly-designed fibers are presented. The seamless integration of luminescence into energy-harvesting fabrics can advance the development of autonomous wearable accessories.

Perceptions of traditional Chinese medicine doctors about using wearable devices and traditional Chinese medicine diagnostic instruments: A mixed-methodology study.

ObjectiveThis study aimed to investigate the perceptions of traditional Chinese medicine doctors about wearable devices and diagnostic instruments and explore the factors that influence them.MethodsData on the perceptions of the traditional Chinese medicine doctors in Hangzhou, China, about wearable devices and diagnostic instruments were collected through face-to-face semi-structured interviews. The author coded the interview responses using grounded theory. A cross-sectional survey was conducted in four traditional Chinese medicine hospitals in Hangzhou, China. The responses of 385 traditional Chinese medicine doctors were considered valid. Descriptive statistics and binary logistic regression models were used for analysis.ResultsThis study categorized the perceptions of traditional Chinese medicine about wearable devices and traditional Chinese medicine diagnostic instruments under convenience, reliability, suitable population, machine usage scenario, and the integration of traditional Chinese medicine and information communication technology. Convenience encompassed portability and the convenience of carrying instruments or wearing the devices and operating them and the human–device interface. Reliability encompassed the underlying principles, accuracy, durability, and reference to diagnosis. Suitability for people encompassed age distinction and disease differentiation. Machine usage scenarios included use in daily life, educational institutions, and primary medical institutions. The combination of traditional Chinese medicine and information communication technology encompassed the integration of traditional Chinese medicine and wearable functions and diagnostic interpretation. The perceptions of traditional Chinese medicine doctors were affected by age, title, type of hospital, and specialty.ConclusionsThe use of wearable devices and traditional Chinese medicine diagnostic instruments has gradually been accepted by traditional Chinese medicine doctors. Traditional Chinese medicine doctors need to improve their knowledge and skills for information communication technology integration, and their standardized training should incorporate information communication technology and digital health.

A Model-Based Method for Minimizing Reflected Motor Inertia in Off-board Actuation Systems: Applications in Exoskeleton Design.

The research and development of wearable robotic devices has been accelerated by off-board control and actuation systems. While off-board robotic actuation systems provide many benefits, the impedance at the robotic joint is often high. High joint impedance is undesirable for wearable devices like exoskeletons, as the user is unable to move their joint without actively controlled motion from the motors. We propose that the impedance can be reduced substantially in off-board robotic actuation systems by minimizing the reflected inertia from the motor. We have developed a model and optimization-based methodology for selecting a motor and set of mechanical design parameters that minimize reflected inertia. This methodology was implemented in the design of an off-board knee exoskeleton as a case study. A grey-box model was developed that incorporates biomechanical knee trajectories, an experimentally determined human-device interface stiffness model, Bowden cable stiffness and friction, and a motor model. A constrained optimization routine was developed that uses the model and a library of157 candidate servo motors to select the actuator and mechanical design parameters that minimize reflected inertia at the exoskeleton joint. We found that S6 of the motors were able to carry out the necessary torque-velocity trajectories to achieve the prescribed exoskeleton joint torques and limb motions. The optimal motor was the Kollmorgen C133A-one of the largest in the library of candidate servo motors and required a 2.25 cm actuator pulley at the knee joint and a 17.5 cm cable sheave at the motor output. This methodology can be adapted by exoskeleton designers to develop more backdriveable exoskeletons and improve experimental capabilities. All code developed for the case study is open-source and freely available online.

Physical interface dynamics alter how robotic exosuits augment human movement: implications for optimizing wearable assistive devices

BackgroundWearable assistive devices have demonstrated the potential to improve mobility outcomes for individuals with disabilities, and to augment healthy human performance; however, these benefits depend on how effectively power is transmitted from the device to the human user. Quantifying and understanding this power transmission is challenging due to complex human-device interface dynamics that occur as biological tissues and physical interface materials deform and displace under load, absorbing and returning power.MethodsHere we introduce a new methodology for quickly estimating interface power dynamics during movement tasks using common motion capture and force measurements, and then apply this method to quantify how a soft robotic ankle exosuit interacts with and transfers power to the human body during walking. We partition exosuit end-effector power (i.e., power output from the device) into power that augments ankle plantarflexion (termed augmentation power) vs. power that goes into deformation and motion of interface materials and underlying soft tissues (termed interface power).ResultsWe provide empirical evidence of how human-exosuit interfaces absorb and return energy, reshaping exosuit-to-human power flow and resulting in three key consequences: (i) During exosuit loading (as applied forces increased), about 55% of exosuit end-effector power was absorbed into the interfaces. (ii) However, during subsequent exosuit unloading (as applied forces decreased) most of the absorbed interface power was returned viscoelastically. Consequently, the majority (about 75%) of exosuit end-effector work over each stride contributed to augmenting ankle plantarflexion. (iii) Ankle augmentation power (and work) was delayed relative to exosuit end-effector power, due to these interface energy absorption and return dynamics.ConclusionsOur findings elucidate the complexities of human-exosuit interface dynamics during transmission of power from assistive devices to the human body, and provide insight into improving the design and control of wearable robots. We conclude that in order to optimize the performance of wearable assistive devices it is important, throughout design and evaluation phases, to account for human-device interface dynamics that affect power transmission and thus human augmentation benefits.

Human Factors Approach to Comparative Usability of Hospital Manual Defibrillators

IntroductionEquipment-related issues have recently been cited as a significant contributor to the suboptimal outcomes of resuscitation management. A systematic evaluation of the human-device interface was undertaken to evaluate the intuitive nature of three different defibrillators. Devices tested were the Physio-Control LifePak 15, the Zoll R Series Plus, and the Philips MRx. MethodsA convenience sample of 73 multidisciplinary health care providers from 5 different hospitals participated in this study. All subjects’ performances were evaluated without any training on the devices being studied to assess the intuitiveness of the user interface to perform the functions of delivering an Automated External Defibrillator (AED) shock, a manual defibrillation, pacing to achieve 100% capture, and synchronized cardioversion on a rhythm simulator. ResultsTimes to deliver an AED shock were fastest with the Zoll, whereas the Philips had the fastest times to deliver a manual defibrillation. Subjects took the least time to attain 100% capture for pacing with the Physio-Control device. No differences in performance times were seen with synchronized cardioversion among the devices. Human factors issues uncovered during this study included a preference for knobs over soft keys and a desire for clarity in control panel design. This study demonstrated no clearly superior defibrillator, as each of the models exhibited strengths in different areas. When asked their defibrillator preference, 67% of subjects chose the Philips. ConclusionsThis comparison of user interfaces of defibrillators in simulated situations allows the assessment of usability that can provide manufacturers and educators with feedback about defibrillator implementation for these critical care devices.

Passive wireless tags for tongue controlled assistive technology interfaces.

Tongue control with low profile, passive mouth tags is demonstrated as a human-device interface by communicating values of tongue-tag separation over a wireless link. Confusion matrices are provided to demonstrate user accuracy in targeting by tongue position. Accuracy is found to increase dramatically after short training sequences with errors falling close to 1% in magnitude with zero missed targets. The rate at which users are able to learn accurate targeting with high accuracy indicates that this is an intuitive device to operate. The significance of the work is that innovative very unobtrusive, wireless tags can be used to provide intuitive human-computer interfaces based on low cost and disposable mouth mounted technology. With the development of an appropriate reading system, control of assistive devices such as computer mice or wheelchairs could be possible for tetraplegics and others who retain fine motor control capability of their tongues. The tags contain no battery and are intended to fit directly on the hard palate, detecting tongue position in the mouth with no need for tongue piercings.

Easily usable human-device interface for microwave therapy apparatus

In this paper we investigate the possibility of using a large dot matrix LCD (Liquid Crystal Display) as the essential part of a low cost, user friendly human-device interface which is driving a microwave diathermy medical apparatus. The human-device interface uses only four buttons with multiple functionalities, an analog encoder and the said dot matrix LCD. The interface is a part of the embedded system that drives the entire unit, as a stand alone hardware and complex firmware program. This interface can handle the medical treatment parameters in an ergonomic and simple way. The human-device interface has been designed in agreement with the EN60601-1 and EN60601-1-4 requirements using “the simple to complex” writing and validation algorithm. The interface has been manufactured as prototype and tested on our own proprietary microwave hyperthermia and diathermy device and proves to be intuitive and easy to use. The human-device interface firmware is portable to other scientific apparatus as well; however, a reconfiguration of all displayed information is necessary, depending on the purpose of the served equipment. Compared with a colour graphic LCD equipped with touch screen, the interface presented here is definitely less expensive, can be implemented faster and uses less hardware resources.

The Experimental Design of App Games to Bridge the Gap between Two Generations

AbstractThe increasingly ageing population is an important issue for family relationships. If the human-device interface is well designed, older citizens can manage icons more easily than typing on a keyboard. The authors use the design of experiment method to evaluate the effect of App games. There are 2*2*2=8 combinations in the experiment. The three factors are image size, touch guidelines and degree of complication. The independent variables are gender, age, technology sensitivity and the attitude to risk. The dependent variable is the game score. It is proven that simplicity, clear guidelines and small screen result in better performance. The elderly like big screens but Apps do bot provide this. These results allow App designers to direct development. More attention to the needs of the elderly during the shooting process might also improve interaction between the elderly and youths.

Organizational Ergonomics in Medical Device Design Standards

Human factors standards for medical devices design are an integral part of new product development. These standards have gained in importance recently. This is mainly due to the increased realization that medical errors, deaths and unsafe events in health care are attributable to human errors. Human factors standards at present mainly relate to human device interface, physical environment and cognitive aspects of device users. The organizational setting plays a crucial role in medical device operation. Medical devices mediate health-care interventions. Organizational settings typically dominate health-care offering. An interaction of these aspects means that organizational factors in medical design standards become significant. This article analyzes organizational factors that need consideration in medical device design standards and standards development organizations.

Human-Device Interface in Catheter Based Interventions

Systematic methods for descriptive analysis of physician hand movements during surgical or catheter based interventions have not been previously reported. Although such data would provide critical guidance in the design of surgical instruments, there is currently little to no information about the chronological and spatial integration of operator movements and user conditions during catheter based interventions. The essential function of the hand is to provide physical coupling between the cognitive process and the environment, translating intention to action. The ideal surgical instrument is a contiguous extension of the haptic unit (the hand) that enables an expanded range of effector actions and environmental effects. In reality, however, there is an interface between the hand and the surgical instrument creating a barrier that can introduce variable levels of interference and impedance between the cognitive process and the intended task. The objective of this project is to analyze surgical effector outputs as a function of operator psychomotor inputs using synchronized multimodal image data recorded during clinical cases of transcatheter neurological intervention. Research methodology consisted of observations and digital recording (video and/or still photography) of 24 diagnostic cerebral angiograms. These were analyzed to synchronously document physician hand movement, surgical effector output (as represented by the fluoroscopic image monitor), spatial orientation feedback (as represented by rotational movements of the fluoroscopic imaging plane with respect to patient anatomical axes), and to identify user specific conditions. The results are presented in a defined procedure map and user behaviors based upon physician experience (e.g., fellow/trainee versus attending physician). As stated in the Association for the Advancement of Medical Instrumentation HE 75 human factors standards for medical device design, there is a clear need to develop human factors standards for endovascular devices. This research will serve as a guide to this effort. The models and multimodal image database generated by this project will also be used in the development of interactive educational tools to train physicians to perform these advanced applications.

Formally verifying human–automation interaction as part of a system model: limitations and tradeoffs

Both the human factors engineering (HFE) and formal methods communities are concerned with improving the design of safety-critical systems. This work discusses a modeling effort that leveraged methods from both fields to perform formal verification of human-automation interaction with a programmable device. This effort utilizes a system architecture composed of independent models of the human mission, human task behavior, human-device interface, device automation, and operational environment. The goals of this architecture were to allow HFE practitioners to perform formal verifications of realistic systems that depend on human-automation interaction in a reasonable amount of time using representative models, intuitive modeling constructs, and decoupled models of system components that could be easily changed to support multiple analyses. This framework was instantiated using a patient controlled analgesia pump in a two phased process where models in each phase were verified using a common set of specifications. The first phase focused on the mission, human-device interface, and device automation; and included a simple, unconstrained human task behavior model. The second phase replaced the unconstrained task model with one representing normative pump programming behavior. Because models produced in the first phase were too large for the model checker to verify, a number of model revisions were undertaken that affected the goals of the effort. While the use of human task behavior models in the second phase helped mitigate model complexity, verification time increased. Additional modeling tools and technological developments are necessary for model checking to become a more usable technique for HFE.

Human factors impact successful lay person automated external defibrillator use during simulated cardiac arrest

With the dissemination of automated external defibrillators in the community, there is increasing lay person use, along with less formal automated external defibrillator training and retraining. Therefore, the "ease of use" factors related to the human-device interface may be vital for successful use. We sought to determine whether human factor differences would result in differences in parameters of successful or safe use by lay persons in the setting of simulated cardiac arrest. We measured parameters of successful and safe use with two automated external defibrillator devices among two groups of volunteers, those trained with a brief video tape and those without any training (completely naive). Both devices (the Philips FR2 or the HS1) are used in public access defibrillator settings. Volunteers entered a mock cardiac arrest scenario after randomization to either the naive (untrained) group or to a video-trained group. Both the FR2 and HS1 were found to be completely safe when used by video-trained and by naive groups of participants, with no adverse events observed (total, n = 256). For both devices, video-trained participants demonstrated high rates of successful defibrillation in the simulated testing (86% for FR2 and 89% for HS1). With the FR2, video-trained participants were significantly more successful compared with naive, untrained participants (86% vs. 48% successful use; p < .001). However, for the HS1, there was no significant difference in success rates for the video-trained vs. naive, untrained groups (89% vs. 87%; p = .79). Both devices are safe with either video-trained or naive users. The successful use of each device is high when participants view the training videotape designed for the device. An important difference in successful use was observed for naive users where the HS1 showed improved successful use compared with the FR2. Because defibrillation in the community may increasingly be attempted by lay persons whose training is remote or who have not been trained at all, the "naive" scenario may be increasingly relevant to automated external defibrillator use. Collectively, these data support the notion that human factors associated with ease of use may play a critical factor in survival rates achieved by specific devices.