Current training and development platforms in robotics assisted surgery often lack an affordable vision system. In this paper we present a cost-effective stereoscopic camera system for surgical training. Our approach utilizes a double parallelogram mechanism to achieve an approximate remote center of motion with three degrees of freedom: two revolute joints for orbital movement and one prismatic joint for depth positioning. The system incorporates two cameras with integrated illumination to provide depth perception. It can be steered hands-free using a head-mounted display, demonstrating the development potential the platform provides. A proof-of-concept evaluation focused on the control system, showing the system’s ability to achieve precise positioning across all three axes with errors of 0.5, 0.2 and 0.1 mm for the X, Y and Z axis respectively. The controllers were tuned to prioritize a smooth transient response without any disturbing oscillations. As a desktop-compatible and modular platform, we hope that this system significantly reduces barriers to surgical robotics in research, development and training.

In rehabilitation of upper limb impairment, grip training is a crucial step and requires a universal approach. To address rehabilitation of somatosensory perception and grip control we present a hand grip assessment and training device with integrated tactile feedback for immersive, interactive therapy. The grip is soft and designed to measures grip force omnidirectionally. Additionally, texture simulation is provided through a high-resolution vibration module, delivering tactile feedback. The mechanical design consists of a base platform and a precisely aligned steel support element that holds a grip measurement unit. The system supports grip measurements and offers a playful, engaging experience designed to enhance patient motivation during therapy by integrating VR game applications. To verify that the proposed device enables omnidirectional grip assessment, we measured the force values by applying the same force at six different angles. Each of the six force values was repeatedly measured across different angles. The device allows users to grip freely, making it suitable for rehabilitation training, and offers significant potential for personalized therapy applications.

The da Vinci Research Kit (dVRK) was introduced in 2012 to provide an affordable, open-source platform for research in robotic minimally-invasive surgery. It provides access to all levels of control but, until now, has relied on an analog controller for the motor current, which cannot easily be customized to improve performance. This paper aims to implement the low-level control digitally and to improve the overall control performance. To enable model-based controller design, the system is first identified using measurements provided by the encoders and internal electronics. The digital current controller is then implemented on the existing field programmable gate array (FPGA). Experiments demonstrate that the new digital current controller yields superior performance compared to the original analog design. In addition, the identified system model is used to design an improved position controller that is also implemented on the FPGA and provides better trajectory tracking than the position controller currently implemented on the control PC. The comparison between simulation and measurement, for both the current and position control, verifies the validity of the model based on the system identification, enabling utilization for future adaptations. The improved low-level control enlarges the possibilities for more accurate operation and the achieved digital implementation enables researchers worldwide to easily adapt the low-level control in future versions of the dVRK.

With rapid developments in virtual reality (VR), haptics, communications technology and digital multimedia, there has been increasing demand for creation and widespread development of more realistic or immersive display systems. Consumers are eager to experience engrossing contents capable of providing presence, beyond traditional audio-visual media. In response to this demand, tactile and haptic interaction is also becoming increasingly important. Recently, MPEG-V standard (ISO/IEC 23005) has been published. The MPEG-V provides architecture and metadata for interaction and interoperability between virtual worlds and real worlds through various sensors and actuators. The aim of this paper is to provide an overview of MPEG-V standard, particularly regarding haptic and tactile interactions.

Sensory function is essential for functional post-stroke recovery and control of basic hand movements like grasping. Despite this fact, therapy focuses strongly on motor aspects of rehabilitation, requiring active participation and thus excluding stroke patients with severe paresis. The aim of our novel therapeutic approach combining virtual reality, based on clinically proven mirror therapy, and tendon vibration of hand and wrist muscles is to induce neuroplastic changes leading to improved hand function. This paper presents the further development and evaluation of a robotic device, which can apply vibrations at precise locations on the finger flexor tendons to create illusions of extension movements and visualize the movements with a virtual hand. A preliminary study including 16 healthy subjects investigated the influence of the virtual reality on the perception of proprioceptive illusory movements. The experimental results provided evidence that the addition of the virtual reality enhanced the perception of the illusory movement generated by tendon vibration, by inducing movements with significantly higher extension (+4.5%, p <; 0.05). Furthermore, the virtual reality allowed a better controlled temporal elicitation of the illusion. These findings indicate the potential of this novel strategy for a more effective therapy, especially for severely impaired patients.

Stroke is the leading cause of long-term disability in adults, with increasing incidence as the population ages. Physical and occupational therapy support the recovery process, with therapy duration and intensity having been identified as critical factors. However, conventional therapy is limited to a short period following the stroke, with only limited possibilities to continue therapy at home. Increasing health costs and lack of trained personnel further strengthen this problem. There is thus a great need for home-based therapy systems, allowing to engage patients and assess the training with sufficient precision to provide meaningful exercises. In this paper, we suggest expandable software architecture for virtual reality rehabilitation applications. This system utilizes various sensors and actuators (i.e. the Kinect for upper limb tracking and a haptic glove). Based on this system, we propose a motion based tactile rendering algorithm. It generates interactive vibration patterns employing the tactile apparent movement phenomenon based on user's movement to enhance the immersion and provide sensory feedback during rehabilitation training in the virtual reality environment. Three rehabilitation game applications are presented as proof of concept of the proposed system.

Stable grasp is the result of sensorimotor regulation of forces, ensuring sufficient grip force and the integrity of the held object. Grasping with a prosthesis introduces the challenge of finding the appropriate forces given the engineered sensorimotor prosthetic interface. Excessive force leads to unnecessary energy use and possible damage to the object. In contrast, low grip forces lead to slippage. In order for a prosthetic hand to achieve a stable grasp, the haptic information provided to the prosthesis wearer needs to display these two antagonistic grasp metrics (force and slip) in a quantified way. We present the design and evaluation of a wearable single-actuator haptic device that relays multi-modal haptic information, such as grip force and slip speed. Two belts that are activated in a mutually exclusive manner by the rotation direction of a single motor exert normal force and tangential motion on the skin surface, respectively. The wearable haptic device is able to display normal forces as a tap frequency in the range of approximately 1.5–5.0 Hz and slip speed in the range of 50–200 mm/s. Within these values, users are able to identify at least four stimulation levels for each feedback modality, with short-term training.

This paper describes investigation on the effectiveness of the haptic feedback in science education, involving 8th grade middle school students. For that study haptically enhanced presentations of the Coriolis Effect have been created based on MPEG-4 framework allowing creating, transmitting and displaying haptically enhanced multimedia educational contents. A special focus of the work is the comparison of the effect of different modalities - i.e. audiovisual feedback only, audiovisual feedback with tactile feedback and audiovisual feedback with kinesthetic feedback - on the learning. The result showed that multimedia contents including haptic feedback can improve student understanding of the Coriolis Effect better than when only the audiovisual feedback content was provided. However, there was no significant difference between tactile and kinesthetic modalities.