Surgery (St Vincent's) - Research Publications
Permanent URI for this collection
Search Results
1 - 3 of 3
-
ItemPsychometric Evaluation of Multi-Point Bone-Conducted Tactile Stimulation on the Three Bony Landmarks of the Elbow(IEEE, 2020)Sensory feedback is highly desirable in upper limb prostheses as well as in human robot interaction and other human machine interfaces. Bone conduction as sensory feedback interface is a recently studied approach showing promising properties. A combination of different feedback information is often necessary for prosthetic grasping, thus multiple feedback channels are required for effective sensory feedback. The use of multiple bone conduction stimulation sites simultaneously has not yet been studied. In this paper, the psychometric evaluation of multiple stimulation sites on the physiologically given bony landmarks on the elbow is investigated. The proposed approach is evaluated on human-subject experiments with six able-bodied subjects and one subject with transradial amputation. Vibrotactile transducers are placed on the bony landmarks of the elbow to determine the identification rate of each stimulation point separately as well as the identification rate of the number of active stimulation points for different frequencies. The outcomes show high identification rates for a frequency range from 100 to 750 Hz whilst performance deteriorates to at chance level at higher frequencies. A decreasing performance in identifying the number of active stimulation sites for an increasing number of simultaneous active transducers was observed. The obtained good performance in location identification suggests that information can be encoded via the location of the stimulation.
-
ItemA practical 3D-printed soft robotic prosthetic hand with multi-articulating capabilities(Public Library of Science (PLoS), 2020-05-14)Soft robotic hands with monolithic structure have shown great potential to be used as prostheses due to their advantages to yield light weight and compact designs as well as its ease of manufacture. However, existing soft prosthetic hands design were often not geared towards addressing some of the practical requirements highlighted in prosthetics research. The gap between the existing designs and the practical requirements significantly hampers the potential to transfer these designs to real-world applications. This work addressed these requirements with the consideration of the trade-off between practicality and performance. These requirements were achieved through exploiting the monolithic 3D printing of soft materials which incorporates membrane enclosed flexure joints in the finger designs, synergy-based thumb motion and cable-driven actuation system in the proposed hand prosthesis. Our systematic design (tentatively named X-Limb) achieves a weight of 253gr, three grasps types (with capability of individual finger movement), power-grip force of 21.5N, finger flexion speed of 1.3sec, a minimum grasping cycles of 45,000 (while maintaining its original functionality) and a bill of material cost of 200 USD (excluding quick disconnect wrist but without factoring in the cost reduction through mass production). A standard Activities Measure for Upper-Limb Amputees benchmark test was carried out to evaluate the capability of X-Limb in performing grasping task required for activities of daily living. The results show that all the practical design requirements are satisfied, and the proposed soft prosthetic hand is able to perform all the real-world grasping tasks of the benchmark tests, showing great potential in improving life quality of individuals with upper limb loss.
-
ItemTactile Feedback in Closed-Loop Control of Myoelectric Hand Grasping: Conveying Information of Multiple Sensors Simultaneously via a Single Feedback Channel.(Frontiers Research Foundation, 2020-04-27)The appropriate sensory information feedback is important for the success of an object grasping and manipulation task. In many scenarios, the need arises for multiple feedback information to be conveyed to a prosthetic hand user simultaneously. The multiple sets of information may either (1) directly contribute to the performance of the grasping or object manipulation task, such as the feedback of the grasping force, or (2) simply form additional independent set(s) of information. In this paper, the efficacy of simultaneously conveying two independent sets of sensor information (the grasp force and a secondary set of information) through a single channel of feedback stimulation (vibrotactile via bone conduction) to the human user in a prosthetic application is investigated. The performance of the grasping task is not dependent to the second set of information in this study. Subject performance in two tasks: regulating the grasp force and identifying the secondary information, were evaluated when provided with either one corresponding information or both sets of feedback information. Visual feedback is involved in the training stage. The proposed approach is validated on human-subject experiments using a vibrotactile transducer worn on the elbow bony landmark (to realize a non-invasive bone conduction interface) carried out in a virtual reality environment to perform a closed-loop object grasping task. The experimental results show that the performance of the human subjects on either task, whilst perceiving two sets of sensory information, is not inferior to that when receiving only one set of corresponding sensory information, demonstrating the potential of conveying a second set of information through a bone conduction interface in an upper limb prosthetic task.