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In the last decade, only 24% of class III life-saving devices approved by the U.S. Food and Drug Administration (FDA) were for pediatric use-and most of those were for children over 12. Of these, less than 4% were labeled for pediatric patients ages 0-2 years old and the number of approved devices is even lower for neonatal patients. For these young patients, adult medical devices are often manipulated by pediatric specialists in order to provide stop-gap solutions. However, these repurposed devices are not always able to fulfill the unique needs of children's biology and growth patterns.

The substantial improvements and innovations in communication networks and bio-medical technologies have led to the adoption of networked medical devices due to which the attack surface has increased profoundly. Numerous devices in practice were designed and developed years ago without security measures. In such a scenario, the role of regulatory bodies has become evident. The Food and Drug Administration (FDA) validates and approves devices before commercialization. In contrast, the European Union (EU) follows a decentralized approach and Notified Bodies (NB) for assuring high standards, safety and quality of medical devices being marketed in Europe. Once the device has gone through stringent regulations including good manufacturing practices, Quality Management System (QMS), labeling, clinical tests, performance standards, adequate storage and packaging practices, a declaration of conformity will be granted, which is a legal binding document stating that the device is conformant with applicable European requirements and can be marketed in Europe. However, such regulations lack a systematic methodology to determine unified security, safety and privacy risk that eventually influence the health of patients. To cover these gaps, this research proposes Integrated Safety, Security, and Privacy (ISSP) Risk Assessment Framework to determine the risk level of the device and required security controls. It is, then applied to a case scenario of an infusion pump and further evaluated by comparing it with current standards and practices. The comparison shows that the framework provides a unified approach to consider different types of risks associated with devices.

At this time many (if not all) colleges and universities are on lockdown, students have returned home, and classes have transitioned to online instruction. Students in capstone design courses around the country have no access to their school's maker spaces and test equipment. Their prototype parts may be stored in a locked maker space, making it difficult to build, test, and deliver prototypes to sponsors or clients at the end of the semester.z.

Objective: The purpose of this paper is to demonstrate the ultrasound tracking strategy for the acoustically actuated bubble-based microswimmer., Methods: The ultrasound tracking performance is evaluated by comparing the tracking results with the camera tracking. A benchtop experiment is conducted to capture the motion of two types of microswimmers by synchronized ultrasound and camera systems. A laboratory developed tracking algorithm is utilized to estimate the trajectory for both tracking methods., Results: The trajectory reconstructed from ultrasound tracking method compares well with the conventional camera tracking, exhibiting a high accuracy and robustness for three different types of moving trajectories., Conclusion: Ultrasound tracking is an accurate and reliable approach to track the motion of the acoustically actuated microswimmers., Significance: Ultrasound imaging is a promising candidate for noninvasively tracking the motion of microswimmers inside the body in biomedical applications and may further promote the real-time control strategy for the microswimmers.

Human body communication (HBC) has emerged as an alternative to radio wave communication for connecting low power, miniaturized wearable, and implantable devices in, on, and around the human body. HBC uses the human body as the communication channel between on-body devices. Previous studies characterizing the human body channel has reported widely varying channel response much of which has been attributed to the variation in measurement setup. This calls for the development of a unifying bio-physical model of HBC, supported by in-depth analysis and an understanding of the effect of excitation, termination modality on HBC measurements. This paper characterizes the human body channel up to 1 MHz frequency to evaluate it as a medium for the broadband communication. The communication occurs primarily in the electro-quasistatic (EQS) regime at these frequencies through the subcutaneous tissues. A lumped bio-physical model of HBC is developed, supported by experimental validations that provide insight into some of the key discrepancies found in previous studies. Voltage loss measurements are carried out both with an oscilloscope and a miniaturized wearable prototype to capture the effects of non-common ground. Results show that the channel loss is strongly dependent on the termination impedance at the receiver end, with up to 4 dB variation in average loss for different termination in an oscilloscope and an additional 9 dB channel loss with wearable prototype compared to an oscilloscope measurement. The measured channel response with capacitive termination reduces low-frequency loss and allows flat-band transfer function down to 13 KHz, establishing the human body as a broadband communication channel. Analysis of the measured results and the simulation model shows that instruments with 50 Ω input impedance (Vector Network Analyzer, Spectrum Analyzer) provides pessimistic estimation of channel loss at low frequencies. Instead, high impedance and capacitive termination should be used at the receiver end for accurate voltage mode loss measurements of the HBC channel at low frequencies. The experimentally validated bio-physical model shows that capacitive voltage mode termination can improve the low frequency loss by up to 50 dB, which helps broadband communication significantly.

Objective: Prosthetic electrical stimulation delivered to the vestibular nerve could provide therapy for people suffering from bilateral vestibular dysfunction. Common encoding methods use pulse-frequency modulation (PFM) to stimulate the semicircular canals of the vestibular system. We previously showed that delivery of ionic direct current (iDC) can also modulate the vestibular system. In this study, we compare the dynamic range of head velocity encoding from iDC modulation to that of PFM controls., Methods: Gentamicin-treated wild-type chinchillas were implanted with microcatheter tubes that delivered ionic current to the left ear vestibular canals and stimulated with steps of anodic/cathodic iDC or PFM. Evoked vestibulo-ocular reflex eye velocity was used to compare PFM and iDC vestibular modulation., Results: Cathodic iDC steps effectively elicited eye rotations consistent with an increased firing rate of the implanted semicircular canal afferents. Anodic iDC current steps elicited eye rotations in the opposite direction that, when paired with an adapted cathodic offset, increased the dynamic range of eye rotation velocities in comparison to PFM controls., Conclusion: Our results suggest that iDC modulation can effectively modulate the vestibular system across a functional range of rotation vectors and velocities, with a potential benefit over a PFM stimulation paradigm., Significance: In conjunction with a safe dc delivery system, iDC modulation could potentially increase the range of simulated head rotation velocities available to neuroelectric vestibular prostheses.

Objective: In teleoperated robot-assisted tasks, the user interacts with manipulators to finely control remote tools. Manipulation of robotic devices, characterized by specific kinematic and dynamic proprieties, is a complex task for the human sensorimotor system due to the inherent biomechanical and neuronal redundancies that characterize the human arm and its control. We investigate how master devices with different kinematics structures and how different task constraints influence users capabilities in exploiting arm redundancy., Methods: A virtual teleoperation workbench was designed and the arm kinematics of seven users was acquired during the execution of two planar virtual tasks, involving either the control of position only or position-orientation of a tool. Using the uncontrolled manifold analysis of arm joint variability, we estimated the logarithmic ratio between the task irrelevant and the task relevant manifolds ( R v )., Results: The R v values obtained in the position-orientation task were higher than in the position only task, while no differences were found between the master devices. A modulation of R v was found through the execution of the position task and a positive correlation was found between task performance and redundancy exploitation., Conclusion: Users exploited additional portions of arm redundancy when dealing with the tool orientation. The R v modulation seems influenced by the task constraints and by the users possibility of reconfiguring the arm position., Significance: This paper advances the general understanding of the exploitation of arm redundancy in complex tasks, and can improve the development of future robotic devices.

Objective: Motivated by the fact that palpation skills are challenging to learn and teach, particularly during Digital Rectal Examinations (DRE), and the lack of understanding of what constitutes adequate performance, we present a visualisation and analysis system that uses small position and pressure sensors located on the examining finger, allowing the quantitative analysis of duration, steps and pressure applied., Methods: The system is first described, followed by an experimental study of twenty experts from four clinical specialties performing ten DREs each on a benchtop model using the proposed system. Analysis of the constitutive steps was conducted to improve understanding of the examination. A Markov model representing executed tasks and analysis of pressure applied is also introduced., Results: The proposed system successfully allowed the visualisation and analysis during the experimental study. General Practitioners and Nurses were found to execute more tasks compared to Urologists and Colorectal Surgeons. Urologists executed the least number of tasks and were the most consistent group compared to others., Conclusion: The ability to "see through" allowed us to better characterise the performance of experts when conducting a DRE on a benchtop model, comparing the performance of relevant specialties, and studying executed tasks and the pressure applied. The Markov model presented summarises task execution of experts and could be used to compare performance of novices against that of experts., Significance: This approach allows for the analysis of performance based on continuous sensor data recording that can be easily extended to real subjects and other types of physical examinations.

Innovative researchers are employing flexible, rather than rigid materials in combination with new design approaches as part of the emerging field of biomedical soft robotics. The idea is to generate tools that conform to and interact with the human body in a much more natural and lightweight way, providing better treatment options for clinicians and translating into better outcomes for patients.

With the advent of low-cost computing platforms, such as Arduino (http://www.arduino.cc) and Raspberry Pi (http://www.raspberrypi.org), it has become clear that lowering the cost barrier and shortening the learning curve, with the backing of a motivated community, would play a transformational role in the way people learn, experiment, and create imaginative solutions to outstanding problems that can benefit from embedded systems.

Around 6 p.m. each evening, the streets of Boston's suburbs come alive with the physically fit and those aspiring to be. They are runners, bikers, walkers, and scooter riders of all different body shapes and ages who would seem to have little in common except one thing-an electronic band wrapped around their wrist. For many of these people, it's hard to imagine life without the daily nagging from a personal health device to meet their daily prescript of 10,000 steps.

For individuals with Type 1 or insulin-requiring Type 2 diabetes, new technology may offer something they desperately need, but is now nigh impossible: the ability to maintain ideal blood glucose levels all day, every day.

This paper proposes the use of an instrumented object for the study of the human grasping strategies. The proposed object is able to measure the grasping forces by means of three Force Sensitive Resistor (FSR) sensors and triaxial acceleration through an accelerometer. The object orientation angles (roll and pitch) can be estimated from the accelerometer output in quasi-static condition, whereas slippage events can be detected through the Power Spectrum Density (PSD) computation of the acceleration on at least one of the three axes. An experimental session on 7 healthy subjects has been performed; each subject used the instrumented object to perform 8 tripod grasp trials. All the sensory information, i.e. applied forces, object orientation and slippage, have been analyzed in order to evaluate the grasping strategies of the different subjects.

In our recent book Health-e Everything: Wearables and the Internet of Things for Health, we capture in an interactive e-book format some global thought-leader perspectives as well as early examples of case studies and novel innovations that are driving this emerging technology domain. Here, we provide a brief snapshot of key findings related to these novel technologies and use cases, which are driving both health care practitioners and health consumers (patients). As technologists, having a firm understanding of customer-driven innovation and the actual user benefits of interconnective devices for health will help us engineer better solutions that are more targeted to the triple aim of better, faster, and cheaper health solutions.

Every year, Doris's primary care physician sends her to see a neurologist to check on her hand tremor, which has increasingly worsened over the past 20 years. Year in and year out, the neurologist asks her to draw a circle on a piece of paper. "The doctor looks at it, says 'Hmm,' and sends me home," Doris explains, adding that she gets no treatment, no recommendations, nothing except a request to schedule next year's appointment.

Approximatley 2% of Americans have a visual disability-vision that cannot be corrected even with the strongest prescription-and in developing countries where infectious disease or untreated cataracts are more common, the percentage is often higher. Many different diseases and conditions can cause low vision, including age-related macular degeneration, diabetic retinopathy, and cone dystrophy (a genetic mutation affecting the cone cells of the retina). People with low vision find everyday activities more challenging. They may not be able to decipher small type, especially text on busy or colored backgrounds; see a plastic toy or other trip hazard left lying on the sidewalk; distinguish faces from more than a few feet away; or read street signs or the route number on a bus to help them get around town.

Forty years ago, Les Baugh lost both of his arms in an electrical accident. With bilateral shoulder-level amputations, his options for prosthetic arms were limited. That changed two years ago, when Baugh underwent a surgical procedure at Johns Hopkins Hospital in Baltimore that allowed him to control state-of-the-art robotic arms using nerves that had been rerouted to his chest. Within ten days of training, he was able to control both arms simultaneously and move a cup from a lower shelf to a higher shelf-a task that previously had been impossible-just by thinking about how he wanted to move his arm.

Advances in medicine have led to a significant increase in human life expectancy and, therefore, to a growing number of disabled elderly people who need chronic care and assistance [1]. The World Health Organization reports that the world's population over 60 years old will double between 2000 and 2050 and quadruple for seniors older than 80 years, reaching 400 million [2]. In addition, strokes, traffic-related and other accidents, and seemingly endless wars and acts of terrorism contribute to an increasing number of disabled younger people.

Nanomaterials such as nanowires, carbon nanotubes, and nanoparticles have already led to breakthroughs in the field of biological and medical sensors. The quantum size effects of the nanomaterials and their similarity in size to natural and synthetic nanomaterials are anticipated to improve sensor sensitivity dramatically. Nanowires are considered as key nanomaterials because of their electrical controllability for accurate measurement, and chemical-friendly surface for various sensing applications. This review covers the working principles and fabrication of silicon nanowire sensors. Furthermore, we review their applications for the detection of viruses, biomarkers, and DNA, as well as for drug discovery. Advances in the performance and functionality of nanowire sensors are also surveyed to highlight recent progress in this area. These advances include the improvements in reusability, sensitivity in high ionic strength solvent, long-term stability, and self-powering. Overall, with the advantages of ultra-sensitivity and the ease of fabrication, it is expected that nanowires will contribute significantly to the development of biological and medical sensors in the immediate future.

The Engineers in Scrubs (EiS) training program at the University of British Columbia, affiliated with the Faculty of Applied Science?s Biomedical Engineering Graduate (BMEG) Program, is not a typical graduate school course. Nor does it follow a traditional master?s course rubric that culminates with a tidy end-of-year project. Rather, the course is designed to push students to prototype innovative medical devices, encourage health care collaborations, and create an unprecedented interface between technology and health care to further medicine.

Humans have the inherent ability to perform highly dexterous tasks with their arms, involving maintenance of posture, movement, and interaction with the environment. The latter requires the human to control the dynamic characteristics of the upper limb musculoskeletal system. These characteristics are quantitatively represented by inertia, damping, and stiffness, which are measures of mechanical impedance. Many previous studies have shown that arm posture is a dominant factor in determining the end point impedance on a horizontal plane. This paper presents the characterization of the end point impedance of the human arm in 3-D space. Moreover, it models the regulation of the arm impedance with muscle cocontraction. The characterization is made by route of experimental trials where human subjects maintained arm posture while their arms were perturbed by a robot arm. Furthermore, the subjects were asked to control the level of their arm muscles' cocontraction, using visual feedback, in order to investigate the effect of muscle cocontraction on the arm impedance. The results of this study show an anisotropic increase of arm stiffness due to muscle cocontraction. These results could improve our understanding of the human arm biomechanics, as well as provide implications for human motor control-specifically the control of arm impedance through muscle cocontraction.

Stroke survivors may benefit from robotic assistance for relearning of functional movements. Current assistive devices are either passive, limited to only two dimensions or very powerful. However, for reach training, weight compensation and a little assistance with limited power is sufficient. We designed and evaluated a novel three-dimensional robotic manipulator, which is able to support the arm weight and assist functional reaching movements. Key points of the design are a damper-based drive train, giving an inherently safe system and its compact and lightweight design. The system is force actuated with a bandwidth of up to 2.3 Hz, which is sufficient for functional arm movements. Maximal assistive forces are 15 N for the up/down and forward/backward directions and 10 N for the left/right direction. Force tracking errors are smaller than 1.5 N for all axes and the total weight of the robot is 25 kg. Furthermore, the device has shown its benefit for increasing reaching distance in a single-case study with a stroke subject. The newly developed system has the technical ability to assist the arm during movement, which is a prerequisite for successful training of stroke survivors. Therapeutic effects of the applied assistance need to be further evaluated. However, with its inherent safety and ease of use, this newly developed system even has the potential for home-based therapeutic training after stroke.

The aging population, prevalence of chronic diseases, and outbreaks of infectious diseases are some of the major challenges of our present-day society. To address these unmet healthcare needs, especially for the early prediction and treatment of major diseases, health informatics, which deals with the acquisition, transmission, processing, storage, retrieval, and use of health information, has emerged as an active area of interdisciplinary research. In particular, acquisition of health-related information by unobtrusive sensing and wearable technologies is considered as a cornerstone in health informatics. Sensors can be weaved or integrated into clothing, accessories, and the living environment, such that health information can be acquired seamlessly and pervasively in daily living. Sensors can even be designed as stick-on electronic tattoos or directly printed onto human skin to enable long-term health monitoring. This paper aims to provide an overview of four emerging unobtrusive and wearable technologies, which are essential to the realization of pervasive health information acquisition, including: (1) unobtrusive sensing methods, (2) smart textile technology, (3) flexible-stretchable-printable electronics, and (4) sensor fusion, and then to identify some future directions of research.

This study presents a novel approach to force feedback in robot-assisted surgery. It consists of substituting haptic stimuli, composed of a kinesthetic component and a skin deformation, with cutaneous stimuli only. The force generated can then be thought as a subtraction between the complete haptic interaction, cutaneous, and kinesthetic, and the kinesthetic part of it. For this reason, we refer to this approach as sensory subtraction. Sensory subtraction aims at outperforming other nonkinesthetic feedback techniques in teleoperation (e.g., sensory substitution) while guaranteeing the stability and safety of the system. We tested the proposed approach in a challenging 7-DoF bimanual teleoperation task, similar to the Pegboard experiment of the da Vinci Skills Simulator. Sensory subtraction showed improved performance in terms of completion time, force exerted, and total displacement of the rings with respect to two popular sensory substitution techniques. Moreover, it guaranteed a stable interaction in the presence of a communication delay in the haptic loop.

This paper introduces the smart tissue anastomosis robot (STAR). Currently, the STAR is a proof-of-concept for a vision-guided robotic system featuring an actuated laparoscopic suturing tool capable of executing running sutures from image-based commands. The STAR tool is designed around a commercially available laparoscopic suturing tool that is attached to a custom-made motor stage and the STAR supervisory control architecture that enables a surgeon to select and track incisions and the placement of stitches. The STAR supervisory-control interface provides two modes: A manual mode that enables a surgeon to specify the placement of each stitch and an automatic mode that automatically computes equally-spaced stitches based on an incision contour. Our experiments on planar phantoms demonstrate that the STAR in either mode is more accurate, up to four times more consistent and five times faster than surgeons using state-of-the-art robotic surgical system, four times faster than surgeons using manual Endo360(°)®, and nine times faster than surgeons using manual laparoscopic tools.

In this paper, the simultaneous real-time control of multiple degrees of freedom (DOF) for myoelectric systems is investigated. The goal of this study, in which ten able-bodied subjects participated, was to directly compare three control paradigms of constrained (force targeted), unconstrained (position targeted) and resisted unconstrained (position targeted) limb contractions. Artificial neural networks (ANNs) were trained for simultaneous myoelectric control of the three degrees of freedom (DOFs) (wrist flexion-extension, abduction-adduction, and pronation-supination) using mirrored bilateral contractions. In the resisted unconstrained experiment, some resistance to movement was provided using flexible wrist braces in order to increase the required level of muscle activation. The force, in constrained experiments, and position, in unconstrained and resisted unconstrained experiments, were measured. The three protocols were compared off-line using estimation accuracies (R2) and online using a real-time computer-based target acquisition test. The constrained control paradigm outperformed the unconstrained method in the abduction-adduction DOF (R(constrained)2 = 90.8 ± 0.6, R(unconstrained)2 = 85.6 ± 1.6) and pronation-supination DOF (R(constrained)2 = 88.5 ± 0.9, R(unconstrained)2 = 82.3 ± 1.6), but no significant difference was found in the flexion-extension DOF. The constrained control method outperformed unconstrained control in two real-time testing metrics including completion time and path efficiency. The constrained method results, however, were not significantly different than those of the resisted unconstrained method (with braces) in both off-line and real-time tests. This suggests that the quality of control using constrained and unconstrained contraction-based myoelectric schemes is not appreciably different when using comparable l- vels of muscle activation.

Deep brain stimulation (DBS) is an established therapy for movement disorders, but the fundamental mechanisms by which DBS has its effects remain unknown. Computational models can provide insights into the mechanisms of DBS, but to be useful, the models must have sufficient detail to predict accurately the electric fields produced by DBS. We used a finite-element method model of the Medtronic 3387 electrode array, coupled to cable models of myelinated axons, to quantify how interpolation errors, electrode geometry, and the electrode-tissue interface affect calculation of electrical potentials and stimulation thresholds for populations of model nerve fibers. Convergence of the potentials was not a sufficient criterion for ensuring the same degree of accuracy in subsequent determination of stimulation thresholds, because the accuracy of the stimulation thresholds depended on the order of the elements. Simplifying the 3387 electrode array by ignoring the inactive contacts and extending the terminated end of the shaft had position-dependent effects on the potentials and excitation thresholds, and these simplifications may impact correlations between DBS parameters and clinical outcomes. When the current density in the bulk tissue is uniform, the effect of the electrode-tissue interface impedance could be approximated by filtering the potentials calculated with a static lumped electrical equivalent circuit. Further, for typical DBS parameters during voltage-regulated stimulation, it was valid to approximate the electrode as an ideal polarized electrode with a nonlinear capacitance. Validation of these computational considerations enables accurate modeling of the electric field produced by DBS.

In this paper, a new method for measuring and monitoring human body joint angles, which uses wearable ultrawideband (UWB) transceivers mounted on body segments, is proposed and investigated. The model is based on providing a high ranging accuracy (intersensor distance) between a pair of transceivers placed on the adjacent segments of the joint center of rotation. The measured distance is then used to compute the joint angles based on the law of cosines. The performance of the method was compared with a flexible goniometer by simultaneously measuring joint flexion-extension angles at different angular velocities, ranging between 8 and 90(°) /s. The measurement errors were evaluated by the average differences between two sets of data (ranging from 0.8(°) for slow movement to 2.8(°) for fast movement), by standard deviation (ranging from 1.2(°) to 4.2(°) for various movement speeds) and by the Pearson correlation coefficient (greater than 0.99) which demonstrates the very good performance of the UWB-based approach. The experimental results have shown that the system has sufficient accuracy for clinical applications, such as rehabilitation.

In this paper, a hybrid brain-computer interface (BCI) system combining P300 and steady-state visual evoked potential (SSVEP) is proposed to improve the performance of asynchronous control. The four groups of flickering buttons were set in the graphical user interface. Each group contained one large button in the center and eight small buttons around it, all of which flashed at a fixed frequency (e.g., 7.5 Hz) to evoke SSVEP. At the same time, the four large buttons of the four groups were intensified through shape and color changes in a random order to produce P300 potential. During the control state, the user focused on a desired group of buttons (target buttons) to evoke P300 potential and SSVEP, simultaneously. Discrimination between the control and idle states was based on the detection of both P300 and SSVEP on the same group of buttons. As an application, this method was used to produce a "go/stop" command in real-time wheelchair control. Several experiments were conducted, and data analysis results showed that combining P300 potential and SSVEP significantly improved the performance of the BCI system in terms of detection accuracy and response time.

Early research on brain-computer interfaces (BCIs) was fueled by the study of event-related potentials (ERPs) by Farwell and Donchin, who are rightly credited for laying important groundwork for the BCI field. However, many other researchers have made substantial contributions that have escaped the radar screen of the current BCI community. For example, in the late 1980s, I worked with a brilliant multidisciplinary research group in electrical engineering at the University of Florida, Gainesville, headed by Dr. Donald Childers. Childers should be well known to long-time members of the IEEE Engineering in Medicine and Biology Society since he was the editor-in-chief of IEEE Transactions on Biomedical Engineering in the 1970s and the recipient of one of the most prestigious society awards, the William J. Morlock Award, in 1973.

Despite the potential increase in precision and accuracy, laser technology is not widely used in neurological surgery. This in part relates to challenges associated with the early introduction of lasers into neurosurgery. Considerable advances in laser technology have occurred, which together with robotic technology could create an ideal platform for neurosurgical application. In this study, a 980-nm contact diode laser was integrated with neuroArm. Preclinical evaluation involved partial hepatectomy, bilateral nephrectomy, splenectomy, and bilateral submandibular gland excision in a Sprague-Dawley rat model (n = 50). Total surgical time, blood loss as weight of surgical gauze before and after the procedure, and the incidence of thermal, vascular, or lethal injury were recorded and converted to an overall performance score. Thermal damage was evaluated in the liver using tissue samples stained with hematoxylin and eosin. Clinical studies involved step-wise integration of the 980-nm laser system into four neurosurgical cases. Results demonstrate the successful integration of contact laser technology into microsurgery, with and without robotic assistance. In preclinical studies, the laser improved microsurgical performance and reduced thermal damage, while neuroArm decreased intra- and intersurgeon variability. Clinical studies demonstrate dutility in meningioma resection (n = 4). Together, laser and robotic technology offered a more consistent, expedient, and precise tool for microsurgery.

The sophistication and success of recently reported microfabricated organs-on-chips and human organ constructs have made it possible to design scaled and interconnected organ systems that may significantly augment the current drug development pipeline and lead to advances in systems biology. Physiologically realistic live microHuman (μHu) and milliHuman (mHu) systems operating for weeks to months present exciting and important engineering challenges such as determining the appropriate size for each organ to ensure appropriate relative organ functional activity, achieving appropriate cell density, providing the requisite universal perfusion media, sensing the breadth of physiological responses, and maintaining stable control of the entire system, while maintaining fluid scaling that consists of ~5 mL for the mHu and ~5 μL for the μHu. We believe that successful mHu and μHu systems for drug development and systems biology will require low-volume microdevices that support chemical signaling, microfabricated pumps, valves and microformulators, automated optical microscopy, electrochemical sensors for rapid metabolic assessment, ion mobility-mass spectrometry for real-time molecular analysis, advanced bioinformatics, and machine learning algorithms for automated model inference and integrated electronic control. Toward this goal, we are building functional prototype components and are working toward top-down system integration.

Recently, implantable brain-machine interfaces (BMIs) for the severely disabled have generated a great deal of excitement in the biomedical community, and clinical trials investigating their use as communication aids have already begun in the United States (these trials are discussed in the "Existing Devices and Trials" section). While the hypothetical societal implications of such devices are often discussed, the relative risks and benefits associated with their clinical use, as well as the alternative options available to patients, are not always part of this discussion. This article therefore seeks to outline the associated ethical concerns of the devices, the user populations for which the devices are intended, and existing noninvasive alternatives.

ISO 9001 requires a company's product design and development process to include specific components [1]. These include design and development planning, design input, design output, design review, design verification and validation, and design transfer. The more our students become familiar with each of these components, the better prepared they will be for careers in the medical device industry. Ideally, capstone design projects would involve each of these components. In situations where this is not possible, lectures regarding the details of each design control component can be included in the capstone course.

Engineering students rarely have an opportunity to delve into the historic antecedents of design in their craft, and this is especially true for biomedical devices. The teaching emphasis is always on the new, the innovative, and the future. Even so, over the last decade, I have coupled a research agenda with engineering special projects into a successful format that allows young biomedical engineering students to understand aspects of their history and learn the complexities of design. There is value in having knowledge of historic engineering achievements, not just for an appreciation of these accomplishments but also for understanding exactly how engineers and clinicians of the day executed their feats-in other words, how the design process works. Ultimately, this particular educational odyssey confirms that history and engineering education are not only compatible but mutually supportive.

The design, implementation, and characterization of a microelectromechanical systems (MEMS) capacitive accelerometer-based middle ear microphone are presented in this paper. The microphone is intended for middle ear hearing aids as well as future fully implantable cochlear prosthesis. Human temporal bones acoustic response characterization results are used to derive the accelerometer design requirements. The prototype accelerometer is fabricated in a commercial silicon-on-insulator (SOI) MEMS process. The sensor occupies a sensing area of 1 mm × 1 mm with a chip area of 2 mm × 2.4 mm and is interfaced with a custom-designed low-noise electronic IC chip over a flexible substrate. The packaged sensor unit occupies an area of 2.5 mm × 6.2 mm with a weight of 25 mg. The sensor unit attached to umbo can detect a sound pressure level (SPL) of 60 dB at 500 Hz, 35 dB at 2 kHz, and 57 dB at 8 kHz. An improved sound detection limit of 34-dB SPL at 150 Hz and 24-dB SPL at 500 Hz can be expected by employing start-of-the-art MEMS fabrication technology, which results in an articulation index of approximately 0.76. Further micro/nanofabrication technology advancement is needed to enhance the microphone sensitivity for improved understanding of normal conversational speech.

This paper presents analysis and design of a radio frequency power and data link for a novel Bone Conduction Implant (BCI) system. Patients with conductive and mixed hearing loss and single-sided deafness can be rehabilitated by bone-anchored hearing aids (BAHA). Whereas the conventional hearing aids transmit sound to the tympanic membrane via air conduction, the BAHA transmits sound via vibrations through the skull directly to the cochlea. It uses a titanium screw that penetrates the skin and needs life-long daily care; it may cause skin infection and redness. The BCI is developed as an alternative to the percutaneous BAHA since it leaves the skin intact. The BCI comprises an external audio processor with a transmitter coil and an implanted unit called the bridging bone conductor with a receiver coil. Using amplitude modulation of the Class-E power amplifier that drives the inductive link, the sound signal is transmitted to the implant through the intact skin. It was found that the BCI can generate enough output force level for candidate patients. Maximum power output of the BCI was designed to occur at 5-mm skin thickness and the variability was within 1.5 dB for 1-8-mm skin thickness variations.

Congenital pulmonary hypoplasia is a devastating condition affecting fetal and newborn pulmonary physiology, resulting in great morbidity and mortality. The fetal lung develops in a fluid-filled environment. In this work, we describe a novel, implantable pressure sensing and recording device which we use to study the pressures present in the fetal pulmonary tree throughout gestation. The system achieves 0.18 cm H2O resolution and can record for twenty one days continuously at 256 Hz. Sample tracings of in vivo fetal lamb recordings are shown.

Monitoring blood flow rate inside prosthetic vascular grafts enables an early detection of the graft degradation, followed by the timely intervention and prevention of the graft failure. This paper presents an inductively powered implantable blood flow sensor microsystem with bidirectional telemetry. The microsystem integrates silicon nanowire (SiNW) sensors with tunable piezoresistivity, an ultralow-power application-specific integrated circuit (ASIC), and two miniature coils that are coupled with a larger coil in an external monitoring unit to form a passive wireless link. Operating at 13.56-MHz carrier frequency, the implantable microsystem receives power and command from the external unit and backscatters digitized sensor readout through the coupling coils. The ASIC fabricated in 0.18-μm CMOS process occupies an active area of 1.5 × 1.78 mm (2) and consumes 21.6 μW only. The sensors based on the SiNW and diaphragm structure provide a gauge factor higher than 300 when a small negative tuning voltage (-0.5-0 V) is applied. The measured performance of the pressure sensor and ASIC has demonstrated 0.176 mmHg/√Hz sensing resolution.

Many researchers and engineers are busy in their laboratories working on devices that will bring mobility to people who have lost function in the lower body due to an accident, stroke, multiple sclerosis, or other disorders. "Several pretty sophisticated exoskeletons are already on the market now, and they are all similar to each other in terms of technologies, but we're not ready to replace the wheelchair yet," said exoskeleton developer Homayoon Kaz Kazerooni, Ph.D., professor of mechanical engineering at the University of California (UC) at Berkeley. "Eventually, we will have devices that are used by individuals on a daily basis to replace wheelchairs but not with the existing technology. We're at the beginning of a much bigger era in exoskeletons."

Vibrotactile displays can extend the perception capabilities of visually impaired persons. Placing such devices on the head promises easy attachment and detachment without reducing other interaction abilities. However, the effectiveness of head-attached vibrotactile displays has never been thoroughly tested. This paper presents the results obtained from experiments with 22 subjects equipped with a display containing 12 coin-type motors equally spaced in a horizontal plane around the upper head region. Our display allowed single- as well as multimotor activation with up to six simultaneously active motors. We identified the minimum and comfort strength of vibrotactile stimulation, and measured the precision in perceiving the accurate number of active motors as well as the precision in localizing the stimuli on the head. While subjects identified the correct number of active motors in 94% of the cases when presented with only one active motor, this precision dropped to 40% for two and down to 5% for five simultaneously active motors. This strongly suggests to avoid multipoint stimulation even though the precision of localizing a position of a stimulus on the head is barely affected by the number of simultaneously active motors. Localization precision, however, varied significantly with the region of the head suggesting that the most front and back regions of the head should be avoided if high precision is required.