Force Sensor

Surgical robotics is one of the most dynamically developing areas of biomedical engineering. In the past few decades, Computer Integrated Interventional Medicine has gained significance internationally in the field of surgical procedures. More recently, mechatronic devices have been used for prostatectomy, neurosurgery, nephrectomy, cholecystectomy, orthopedics and radiosurgery. The paper both introduces surgical robotics and the basics of force control. It also provides a review on the different algorithms and control paradigms developed for interventional systems. The application of force sensors and force based control algorithms gives a natural extension to these systems allowing for higher quality human-machine interaction, more realistic sensory feedback and telepresence. Precise and effective control of robotic devices in a changing environment can be realized with force control. Beyond, it can apply important safety features. Different methods are presented to overcome the physical limitations of instrument sensorization, and force control algorithms tailored to medical robotic applications.

In this work, a novel technological approach to the early diagnosis of neuro-developmental disorders is presented. Disorders such as Autism are typically diagnosed after language development, i.e. after the 2-3 years of age. In this paper, three different typologies of instruments are presented which are designed to assess infants behavior in different perceptual and motor domains. The first is an instrumented toy embedding kinematic and force sensors for studying grasping and manipulation in infants as young as 6 months old. The second is a wearable device for sensing the kinematics of the upper and lower limbs of infants, designed to assess spontaneous movements in premature babies. The third is a multimodal audio-visuo-vestibular cap which was designed to assess infants orienting behaviors in social situations in response to audio and visual stimuli.

Gait restoration is an integral part of rehabilitation of brain lesioned patients. Modern concepts favour a task-specific repetitive approach, i.e. who wants to regain walking has to walk, while tone-inhibiting and gait preparatory manoeuvres had dominated therapy before. Following the first mobilization out of the bed, the wheelchair-bound patient should have the possibility to practise complex gait cycles as soon as possible. Steps in this direction were treadmill training with partial body weight support and most recently gait machines enabling the repetitive training of even surface gait and even of stair climbing. With treadmill training harness-secured and partially relieved wheelchair-mobilised patients could practise up to 1000 steps per session for the first time. Controlled trials in stroke and SCI patients, however, failed to show a superior result when compared to walking exercise on the floor. Most likely explanation was the effort for the therapists, e.g. manually sett...

and in many other medical research domains aiming at the understanding of physiological motor and cognitive basic mechanisms. The systematic application of robotic and mechatronic technologies to realize new tools and measurement methods for quantitatively assessing motor and cognitive functions in humans as well as in animal models is gaining an increasing popularity. This work represents a first step towards the development of a sensorised environment for behavioral phenotyping of animal models. In particular, this paper focuses on tremor analysis in reeler mice, an emerging potential animal model for anatomical and behavioral traits observed in autism. Ground Reaction Force (GRF) sensing is indeed the most direct means of measuring tremor. Although force platforms have extensively been used for large size animals, only few attempts have been made to measure GRF at a single paw for animals as small as mice or rats. Under the hypothesis that in-plane GRF components are directly connected to tremor, a small size, modular, mechanically simple, 2-axis force sensor for measuring the in-plane components of GRF was designed and developed. Special care was paid to design a structure that allowed self-aligned assembly, for repeatability and modularity for combining multiple platforms for a sensorised floor. Thanks to the use of two different sensors (acceleration and distance sensors) an in-situ calibration procedure has been planned to be performed directly in Neuroscience labs without use of a structured environment and/or engineering skills. Preliminarily testing was performed with both reeler and wildtype mice. Fourier analysis validated the hypothesis of a direct connection between tremor and in-plane GRFs. Data analyzed and filtered highlight a peculiar spectrum frequency in Reeler mice tremor, centered at about 20 Hz.

Muscular hyperactivity during handwriting, irregular and jerky scripts, as well as awkward and slowed pen movements are the cardinal symptoms of writer's cramp. Accordingly, impaired kinematics and increased force have been reported in writer's cramp. However, the relationship between these symptoms has rarely been investigated. In addition, measurements of finger forces have been restricted to the vertical pen pressure. In the present study, the pen of a graphic tablet was equipped with a force sensor matrix to measure also the grip force produced against the pen barrel despite highly variable pen grips of the patients. Kinematics of writing movements, vertical pen pressure, and grip force were compared in 27 patients with writer's cramp and normal control writers during writing of a test sentence. As expected, all measures revealed a significantly worse writing performance in the patients compared to the control subjects. Exaggerated forces were more frequent than abnormal kinematics, and evidenced by prolonged movement times and reduced writing frequencies. Correlations were found neither between kinematics and force measures nor between the two forces. Interestingly, patients relaxed the grip force during short periods of non-writing by the same relative amount as control subjects. The finding of a large heterogeneity of performances patterns in writer's cramp may reflect the variability of dystonic symptoms as well as the highly variable compensatory strategies of individual patients. Measurements of finger force and in particular of the grip force are valuable and important descriptors of 0167-9457/$ -see front matter Ó

Any architectural optimization aims at satisfying the end user. However, modern architectures execute with little to no knowledge about the individual user. If architectures could determine whether their users are satisfied, they could provide higher efficiency; improved reliability, reduced power consumption, increased security, and a better user experience. A major reason for this limitation is their input devices. Specifically, the traditional input devices (e.g., the mouse and keyboard) provide limited information about the user. In this paper, we make a case for the addition of new biometric input devices for providing the computer information about the user's physiological traits. We explore three biometric devices as potential sensors: an eye tracker, a galvanic skin response (GSR) sensor, and force sensors. We first present two user studies that explore the link between the sensor readings and user satisfaction when the performance of the processor is varied as a video game is being played. In the first study, we drastically drop the processor clock frequency at a set point in the game. In the second study, we set the clock frequency to randomly-selected levels during game play. Both studies show that there are significant changes in human physiological traits as performance decreases. More importantly, we show that physiological changes correlate strongly to the satisfaction levels reported by the users. Based upon these observations, we construct a Physiological Traitsbased Power-management (PTP) system that can be applied to existing dynamic voltage and frequency scaling (DVFS) schemes. We apply PTP to a typical CPU-utilization-based adaptive DVFS policy and evaluate our scheme using a third user study. An aggressive version of our PTP scheme reduces the total system power consumption of a laptop by up to 33.3% for an application averaged across users (18.1% averaged across three applications), while a conservative version reduces the total system power consumption by up to 25.6% across users (11.4% averaged across three applications).