Haptic devices as an educational approach for oral and maxillofacial surgical procedures.

OBJECTIVE: Developing the skills of a proficient surgeon with a deep understanding of force requires extensive training and repetitive practice. Traditionally, dental students and surgical trainees observed and participated in procedures using models, animals, or cadavers under expert supervision before performing the procedures independently. To address these challenges, interactive simulators with visuo-haptic features have been introduced in surgical training, providing visual and tactile feedback that replicates the sense of touch through applied forces, vibrations, or motions. STUDY DESIGN: Two independent reviewers employed a specific search strategy to explore online databases such as PubMed, Scopus, and Web of Science (WoS). This strategy included keywords such as "haptic device," "education," "oral surgery," "surgery," and "maxillofacial surgery." All types of studies related to maxillofacial surgery, except for case reports, reviews, and eBooks, were considered for inclusion. RESULTS: A total of 22 articles meeting the screening criteria were identified. The use of haptic devices for training dental students in oral surgery, anesthesia, as well as oral and maxillofacial trainees and surgeons in various surgical procedures, was evaluated. CONCLUSION: Incorporating tactile devices into the training of residents and maxillofacial surgeons offers numerous advantages, including improved technical skills and enhanced patient safety.

Encoding contact size using static and dynamic electrotactile finger stimulation: natural decoding vs. trained cues.

Electrotactile stimulation through matrix electrodes is a promising technology to restore high-resolution tactile feedback in extended reality applications. One of the fundamental tactile effects that should be simulated is the change in the size of the contact between the finger and a virtual object. The present study investigated how participants perceive the increase of stimulation area when stimulating the index finger using static or dynamic (moving) stimuli produced by activating 1 to 6 electrode pads. To assess the ability to interpret the stimulation from the natural cues (natural decoding), without any prior training, the participants were instructed to draw the size of the stimulated area and identify the size difference when comparing two consecutive stimulations. To investigate if other "non-natural" cues can improve the size estimation, the participants were asked to enumerate the number of active pads following a training protocol. The results demonstrated that participants could perceive the change in size without prior training (e.g., the estimated area correlated with the stimulated area, p < 0.001; ≥ two-pad difference recognized with > 80% success rate). However, natural decoding was also challenging, as the response area changed gradually and sometimes in complex patterns when increasing the number of active pads (e.g., four extra pads needed for the statistically significant difference). Nevertheless, by training the participants to utilize additional cues the limitations of natural perception could be compensated. After the training, the mismatch in the activated and estimated number of pads was less than one pad regardless of the stimulus size. Finally, introducing the movement of the stimulus substantially improved discrimination (e.g., 100% median success rate to recognize ≥ one-pad difference). The present study, therefore, provides insights into stimulation size perception, and practical guidelines on how to modulate pad activation to change the perceived size in static and dynamic scenarios.

AI enhanced collaborative human-machine interactions for home-based telerehabilitation.

The use of robots in a telerehabilitation paradigm could facilitate the delivery of rehabilitation on demand while reducing transportation time and cost. As a result, it helps to motivate patients to exercise frequently in a more comfortable home environment. However, for such a paradigm to work, it is essential that the robustness of the system is not compromised due to network latency, jitter, and delay of the internet. This paper proposes a solution to data loss compensation to maintain the quality of the interaction between the user and the system. Data collected from a well-defined collaborative task using a virtual reality (VR) environment was used to train a robotic system to adapt to the users' behaviour. The proposed approach uses nonlinear autoregressive models with exogenous input (NARX) and long-short term memory (LSTM) neural networks to smooth out the interaction between the user and the predicted movements generated from the system. LSTM neural networks are shown to learn to act like an actual human. The results from this paper have shown that, with an appropriate training method, the artificial predictor can perform very well by allowing the predictor to complete the task within 25 s versus 23 s when executed by the human.

Soft Robotic Glove with Sensing and Force Feedback for Rehabilitation in Virtual Reality.

Many diseases, such as stroke, arthritis, and spinal cord injury, can cause severe hand impairment. Treatment options for these patients are limited by expensive hand rehabilitation devices and dull treatment procedures. In this study, we present an inexpensive soft robotic glove for hand rehabilitation in virtual reality (VR). Fifteen inertial measurement units are placed on the glove for finger motion tracking, and a motor-tendon actuation system is mounted onto the arm and exerts forces on fingertips via finger-anchoring points, providing force feedback to fingers so that the users can feel the force of a virtual object. A static threshold correction and complementary filter are used to calculate the finger attitude angles, hence computing the postures of five fingers simultaneously. Both static and dynamic tests are performed to validate the accuracy of the finger-motion-tracking algorithm. A field-oriented-control-based angular closed-loop torque control algorithm is adopted to control the force applied to the fingers. It is found that each motor can provide a maximum force of 3.14 N within the tested current limit. Finally, we present an application of the haptic glove in a Unity-based VR interface to provide the operator with haptic feedback while squeezing a soft virtual ball.

Generating Clear Vibrotactile Cues with a Magnet Embedded in a Soft Finger Sheath.

Haptic displays act on the user's body to stimulate the sense of touch and enrich applications from gaming and computer-aided design to rehabilitation and remote surgery. However, when crafted from typical rigid robotic components, they tend to be heavy, bulky, and expensive, while sleeker designs often struggle to create clear haptic cues. This article introduces a lightweight wearable silicone finger sheath that can deliver salient and rich vibrotactile cues using electromagnetic actuation. We fabricate the sheath on a ferromagnetic mandrel with a process based on dip molding, a robust fabrication method that is rarely used in soft robotics but is suitable for commercial production. A miniature rare-earth magnet embedded within the silicone layers at the center of the finger pad is driven to vibrate by the application of alternating current to a nearby air-coil. Experiments are conducted to determine the amplitude of the magnetic force and the frequency response function for the displacement amplitude of the magnet perpendicular to the skin. In addition, high-fidelity finite element analyses of the finger wearing the device are performed to investigate the trends observed in the measurements. The experimental and simulated results show consistent dynamic behavior from 10 to 1000 Hz, with the displacement decreasing after about 300 Hz. These results match the detection threshold profile obtained in a psychophysical study performed by 17 users, where more current was needed only at the highest frequency. A cue identification experiment and a demonstration in virtual reality validate the feasibility of this approach to fingertip haptics.

A Cost-Effective, Integrated Haptic Device for an Exoskeletal System.

The paper presents an innovative integrated sensor-effector designed for use in exoskeletal haptic devices. The research efforts aimed to achieve high cost-effectiveness for a design assuring proper monitoring of joint rotations and providing passive force feedback. A review of market products revealed that there is space for new designs of haptic devices with such features. To determine the feasibility of the proposed solution, a series of simulations and experiments were conducted to verify the adopted design concept. The focus was set on an investigation of the force of attraction between one and two magnets interacting with a steel plate. Further, a physical model of an integrated joint was fabricated, and its performance was evaluated and compared to a similar commercially available device. The proposed solution is cost-effective due to the use of standard parts and inexpensive components. However, it is light and assures a 19 Nm braking torque adequate for the intended use as a haptic device for upper limbs.

Robotic ultrasound: An initial feasibility study.

BACKGROUND: Performing ultrasound during the current pandemic time is quite challenging. To reduce the chances of cross-infection and keep healthcare workers safe, a robotic ultrasound system was developed, which can be controlled remotely. It will also pave way for broadening the reach of ultrasound in remote distant rural areas as well. AIM: To assess the feasibility of a robotic system in performing abdominal ultrasound and compare it with the conventional ultrasound system. METHODS: A total of 21 healthy volunteers were recruited. Ultrasound was performed in two settings, using the robotic arm and conventional hand-held procedure. Images acquired were analyzed by separate radiologists. RESULTS: Our study showed that the robotic arm model was feasible, and the results varied based on the organ imaged. The liver images showed no significant difference. For other organs, the need for repeat imaging was higher in the robotic arm, which could be attributed to the radiologist's learning curve and ability to control the haptic device. The doctor and volunteer surveys also showed significant comfort with acceptance of the technology and they expressed their desire to use it in the future. CONCLUSION: This study shows that robotic ultrasound is feasible and is the need of the hour during the pandemic.

Development of a Wearable Haptic Glove Presenting Haptic Sensation by Electrical Stimulation.

Most haptic devices generate haptic sensation using mechanical actuators. However, the workload and limited workspace handicap the operator from operating freely. Electrical stimulation is an alternative approach to generate haptic sensations without using mechanical actuators. The light weight of the electrodes adhering to the body brings no limitations to free motion. Because a real haptic sensation consists of feelings from several areas, mounting the electrodes to several different body areas can make the sensations more realistic. However, simultaneously stimulating multiple electrodes may result in "noise" sensations. Moreover, the operators may feel tingling because of unstable stimulus signals when using the dry electrodes to help develop an easily mounted haptic device using electrical stimulation. In this study, we first determine the appropriate stimulation areas and stimulus signals to generate a real touch sensation on the forearm. Then, we propose a circuit design guideline for generating stable electrical stimulus signals using a voltage divider resistor. Finally, based on the aforementioned results, we develop a wearable haptic glove prototype. This haptic glove allows the user to experience the haptic sensations of touching objects with five different degrees of stiffness.

Development of a vibrotactile cueing device that implicitly increases walking speed during gait training in stroke patients: an observational case series study.

One of the main sequelae of stroke is difficulty walking, which is characterised by decreased walking speed and asymmetrical walking patterns. Physical therapists often rely on explicit motor learning strategies, i.e., providing mainly verbal instructions for how movements should be performed. However, the voluntary movement induced by explicit instruction may lead to associated unintended muscle contractions or higher cognitive demand, which could be detrimental. We introduce a vibrotactile cueing device that implicitly improves walking speed. The stroke patient walks while alternating vibrational cues are given to the left and right sides of their waist. At each specified step, cueing frequency increases in the cueing group without the patient's awareness. The four patients in the cueing group did not notice the increase in walking speed during training; however, we observed an improvement in walking speed and cadence in patients using the proposed cueing system, which was maintained during the posttest phase. Additionally, patients using the cueing system were able to suppress excessive compensatory movements during training compared with patients who did not use the system. This case series study indicates that the proposed system for gait rehabilitation of stroke patients can enable an increase in walking speed without excessive effort.

Case study assessing the feasibility of using a wearable haptic device or humanoid robot to facilitate transitions in occupational therapy sessions for children with autism spectrum disorder.

INTRODUCTION: Some children with autism spectrum disorder (ASD) have difficulties with transitions that may lead to problem behaviours. Although the use of technologies with children with ASD is receiving increasing attention, no study has looked at their effect on transitions in activities of daily living. This study aimed to document the feasibility of (1) using two intervention technologies (NAO humanoid robot or wearable haptic device) separately to facilitate transitions in occupational therapy sessions for children with ASD and (2) the method used to document changes. METHODS: Using a single case reversal (ABA) design, two children with ASD were randomly assigned to one of the intervention technologies (humanoid robot or haptic bracelet). Each technology was used as an antecedent to stimulate the start of transitions in eight intervention sessions at a private occupational therapy clinic. Data concerning the time required for transitions, child's behaviours during transitions at the clinic and mother's perception of the child's performance in transitions at home were analysed graphically. RESULTS: When using technology, both children's behaviours were appropriate, quick and relatively stable. Also, both mothers reported improved perceptions of their child's performance in transitions. CONCLUSIONS: This exploratory study suggests no detrimental effect of using these technologies.

Design of a Wearable Haptic Device for Hand Palm Cutaneous Feedback.

This study describes the main design and prototyping steps of a novel haptic device for cutaneous stimulus of a hand palm. This part of the hand is fundamental in several grasping and manipulation tasks, but is still less exploited in haptics applications than other parts of the hand, as for instance the fingertips. The proposed device has a parallel tendon-based mechanical structure and is actuated by three motors positioned on the hand's back. The device is able to apply both normal and tangential forces and to render the contact with surfaces with different slopes. The end-effector can be easily changed to simulate the contact with different surface curvatures. The design is inspired by a smaller device previously developed for the fingertips; however, in the device presented in this study, there are significant differences due to the wider size, the different form-factor, and the structure of hand palm. The hand palm represents the support for the fingers and is connected to the arm through the wrist. The device has to be developed taking into account fingers' and wrist's motions, and this requirement constrains the number of actuators and the features of the transmission system. The larger size of the palm and the higher forces challenge the device from a structural point of view. Since tendons can apply only tensile forces, a spring-based support has been developed to keep the end-effector separated from the palm when the device is not actuated or when the force to be rendered is null. The study presents the main design guidelines and the main features of the proposed device. A prototype has been realized for the preliminary tests, and an application scenario with a VR environment is introduced.

Robust Control of a New Asymmetric Teleoperation Robot Based on a State Observer.

This study is mainly about the designation of a new type of haptic device and an asymmetric teleoperation robot system. Aiming at the problems of tracking and transparency of an asymmetric teleoperation system, a robust control algorithm based on a state observer was proposed. The Haptic Device was designed and was chosen as the master-robot of the system. The Baxter dual-arm robot was chosen as the slave-robot of the system. The simulation experiment of robust control based on a state observer of the asymmetric teleoperation robot was carried out. The experiment results showed that the maximum values of displacement tracking errors in three directions x, y, and z are 0.02 m, 0.01 m, and 0.015 m, respectively. Compared with single- joint PID control, the performance of the new control algorithm is improved. The force feedback experiment on the real asymmetric teleoperation robot system was carried out. The results showed that the force feedback wave is consistent with the actual situation and showed that the robust control algorithm proposed is superior to PID. Therefore, the algorithm perfectly satisfied the system. The experiment parameters also demonstrate that the haptic device satisfies the design requirements of the asymmetric teleoperation robots system and the industry standards.

The speed of adaptation is dependent on the load type during target reaching by intact human subjects.

When lifting or moving a novel object, humans are routinely able to quickly characterize the nature of the unknown load and swiftly achieve the desired movement trajectory. It appears that both tactile and proprioceptive feedback systems help humans develop an accurate prediction of load properties and determine how associated limb segments behave during voluntary movements. While various types of limb movement information, such as position, velocity, acceleration, and manipulating forces, can be detected using human tactile and proprioceptive systems, we know little about how the central nervous system decodes these various types of movement data, and in which order or priority they are used when developing predictions of joint motion during novel object manipulation. In this study, we tested whether the ability to predict motion is different between position- (elastic), velocity- (viscous), and acceleration-dependent (inertial) loads imposed using a multiaxial haptic robot. Using this protocol, we can learn if the prediction of the motion model is optimized for one or more of these types of mechanical load. We examined ten neurologically intact subjects. Our key findings indicated that inertial and viscous loads showed the fastest adaptation speed, whereas elastic loads showed the slowest adaptation speed. Different speeds of adaptation were observed across different magnitudes of the load, suggesting that human capabilities for predicting joint motion and manipulating loads may vary systematically with different load types and load magnitudes. Our results imply that human capabilities for load manipulation seems to be most sensitive to and potentially optimized for inertial loads.

A Soft Haptic Glove Actuated with Shape Memory Alloy and Flexible Stretch Sensors.

Haptic technology allows us to experience tactile and force sensations without the need to expose ourselves to specific environments. It also allows a more immersive experience with virtual reality devices. This paper presents the development of a soft haptic glove for kinesthetic perception. It is lightweight and soft to allow for a more natural hand movement. This prototype actuates two fingers with two shape memory alloy (SMA) springs. Finite element (FE) simulations of the spring have been carried out to set the dimensions of the actuators. Flexible stretch sensors provide feedback to the system to calculate the tension of the cables attached to the fingers. The control can generate several recognizable levels of force for any hand position since the objects to be picked up can vary in weight and dimension. The glove can generate three levels of force (100, 200 and 300 g) to evaluate more easily the proper functioning. We realized tests on 15 volunteers simulating forces in various order after a quick training. We also asked volunteers about the experience for comfort, global experience and simplicity). Results were satisfactory in both aspects: the glove fulfilled its function, and the users were comfortable with it.

Using a robotic teleoperation system for haptic exploration.

INTRODUCTION: When children with physical impairments cannot perform hand movements for haptic exploration, they miss opportunities to learn about object properties. Robotics systems with haptic feedback may better enable object exploration. METHODS: Twenty-four adults and ten children without physical impairments, and one adult with physical impairments, explored tools to mix substances or transport different sized objects. All participants completed the tasks with both a robotic system and manual exploration. Exploratory procedures used to determine object properties were also observed. RESULTS: Adults and children accurately identified appropriate tools for each task using manual exploration, but they were less accurate using the robotic system. The adult with physical impairment identified appropriate tools for transport in both conditions, however had difficulty identifying tools used for mixing substances. A new exploratory procedure was observed, Tapping, when using the robotic system. CONCLUSIONS: Adults and children could make judgements on tool utility for tasks using both manual exploration and the robotic system, however they experienced limitations in the robotics system that require more study. The adult with disabilities required less assistance to explore tools when using the robotic system. The robotic system may be a feasible way for individuals with physical disabilities to perform haptic exploration.

An early warning system for diabetic automobile drivers with peripheral neuropathy.

PURPOSE: People with Type 2 diabetes exhibit peripheral neuropathy that results in the progressive loss of sensation in their feet. This may adversely affect their ability to drive as there is the potential for their foot to slip off the accelerator or brake pedals, with unwanted consequences including traffic accidents. This research aimed to develop a prototype for an adaptive haptic foot device for diabetic drivers experiencing peripheral neuropathy that can serve as an early warning system for foot slip during driving. METHODS: A prototype system was designed in the laboratory which consisted of four force sensing resistors, four light emitting diodes and an eccentric rotating mass all connected and programmed through an Arduino Uno. The prototype was tested under controlled conditions and validated against recommended specifications. The system was then installed in a Ford Falcon GT 2005 and tested under controlled road conditions. RESULTS: The results indicated that the haptic device was effective in sensing foot locations and providing instant audio and video feedback to the driver. CONCLUSION: This research has successfully designed and fabricated a haptic feedback device that can be used as an early warning system for diabetic automobile drivers with peripheral neuropathy.IMPLICATIONS FOR REHABILITATIONA haptic foot prototype device capable of generating warning signals to diabetic drivers whose foot could slip off the brake or accelerator pedals has been developed.The prototype includes force sensing receivers integrated with eccentric rotating mass system, a haptic controller breakout board, and Arduino software.The system is very easy to use and provides highly reliable audio and visual feedback which are good alerting mechanisms for older automobile drivers.

Can Virtual Reality Be Used to Track Skills Decay During the Research Years?

BACKGROUND: Time away from surgical practice can lead to skills decay. Research residents are thought to be prone to skills decay, given their limited experience and reduced exposure to clinical activities during their research training years. This study takes a cross-sectional approach to assess differences in residents' skills at the beginning and end of their research years using virtual reality. We hypothesized that research residents will have measurable decay in psychomotor skills when evaluated using virtual reality. METHODS: Surgical residents (n = 28) were divided into two groups; the first group was just beginning their research time (clinical residents: n = 19) and the second group (research residents: n = 9) had just finished at least 2 y of research. All participants were asked to perform a target-tracking task using a haptic device, and their performance was compared using Welch's t-test. RESULTS: Research residents showed a higher level of "tracking error" (1.69 ± 0.44 cm versus 1.40 ± 0.19 cm; P = 0.04) and a similar level of "path length" (62.5 ± 10.5 cm versus 62.1 ± 5.2 cm; P = 0.92) when compared with clinical residents. CONCLUSIONS: The increased "tracking error" among residents at the end of their research time suggests fine psychomotor skills decay in residents who spend time away from clinical duties during laboratory time. This decay demonstrates the need for research residents to regularly participate in clinical activities, simulation, or assessments to minimize and monitor skills decay while away from clinical practice. Additional longitudinal studies may help better map learning and decay curves for residents who spend time away from clinical practice.

CombX: Design and experimental characterizations of a haptic device for surgical teleoperation.

BACKGROUND: Haptic devices with active translation and orientation outputs are highly preferred in surgical teleoperation. However, commercial products are expensive, while state-of-the-art research prototypes are difficult to reproduce outside the original laboratories. METHODS: This paper presents the design and experimental characterizations of two styluses for the CombX, a haptic device with both force and torque outputs constructed from two TouchX haptic devices, which have only force outputs at their styluses. The arrangement was optimized to improve the specifications. Additional functions for surgical teleoperation were also integrated. RESULTS: The CombX has a translation workspace larger than 160 × 160 × 160 mm3 . After calibration, it can provide force outputs of up to 16.32 N and torque outputs of up to 316 mNm. The CombX has also been successfully used to teleoperate a continuum surgical manipulator for two surgical tasks. CONCLUSION: The results show that the CombX is a viable option for surgical teleoperation.

Closed-Loop Haptic Feedback Control Using a Self-Sensing Soft Pneumatic Actuator Skin.

In this article, we achieve a closed-loop control over haptic feedback, first time for an entirely soft platform. We prototyped a novel self-sensing soft pneumatic actuator (SPA) with soft strain sensors, called SPA-skin, which withstands large multiaxial strains and is capable of high-frequency sensing and actuation. To close-loop control the haptic feedback, the platform requires a cohesively integrated system. Our system consists of a stretchable low profile (<500 µm) SPA and an ultra-compliant thin-metal film strain sensor that create a novel bidirectional platform for tactile sensing via force-tunable vibratory feedback. With this prototype, we demonstrated control of the actuator shape in real time up to 100 Hz at output forces up to 1 N, maintained under variable mechanical loadings. We further characterized the SPA-skin platform for its static and dynamic behavior over a range of actuation amplitudes and frequencies as well as developed an analytical model of this system to predict the actuator inflation state only using the embedded sensor's resistance. Our SPA-skin is a multifunctional multilayer system that can readily be implemented as a high-speed wearable bidirectional interface for contact sensing and vibrotactile feedback.

Proposal of the Tactile Glove Device.

This project aims to develop a tactile glove device and a virtual environment inserted in the context of tactile internet. The tactile glove allows a human operator to interact remotely with objects from a 3D environment through tactile feedback or tactile sensation. In other words, the human operator is able to feel the contour and texture from virtual objects. Applications such as remote diagnostics, games, remote analysis of materials, and others in which objects could be virtualized can be significantly improved using this kind of device. These gloves have been an essential device in all research on the internet next generation called "Tactile Internet", in which this project is inserted. Unlike the works presented in the literature, the novelty of this work is related to architecture, and tactile devices developed. They are within the 10 ms round trip latency limits required in a tactile internet environment. Details of hardware and software designs of a tactile glove, as well as the virtual environment, are described. Results and comparative analysis about round trip latency time in the tactile internet environment is developed.