A Review of Non-Invasive Haptic Feedback stimulation Techniques for Upper Extremity Prostheses <s> Vibration Feedback Display <s> Tactile displays have a wide range of applications in assistive technology, prosthetics, and rehabilitation. Vibrotactile stimulation shows potential to be integrated into wearable devices because of its small size, low power consumption, and relative fast responding speed. In this paper, experiments investigating vibrotactile minimal detectable level, just noticeable difference, and two point discrimination distance using eccentric rotating mass (ERM) and linear resonant actuator (LRA) are described and the results were analyzed. LRAs have shown potential to transmit binary information, while ERMs are more suitable for conveying more complexed signals. For both LRAs and ERMs, it is difficult to for subjects to correctly distinguish two points within 45 mm. <s> BIB001 </s> A Review of Non-Invasive Haptic Feedback stimulation Techniques for Upper Extremity Prostheses <s> Vibration Feedback Display <s> Lack of haptic feedback in prostheses is proving to be the bottleneck in the field. Closed loop prostheses should fill the gap for amputees to experience exteroceptive (environmental pressure) or proprioceptive (proper state or joint angles) by means of different sensory feedback. Detailed work is being done on the development of electrotactile and vi-brotactile stimulation system. The objective of this research is to generate vibrotactile feedback on a residual arm of an amputee. With this research, it is an endeavor for amputees to possess cognitive response while holding something amid environmental interactions with the help of convenient methodology and with suitable components in hand. To make this design pertinent to the objective, we have used coin shaped vibration motors, 0.5-inch diameter circular FSR provide haptic feedback from the tip of the finger. 3D printed prosthetic hand proved to be the best remedy for lowering the cost. The research was conducted on 6 healthy subjects and one amputee. Experimental results showed the effectiveness of proposed approach. <s> BIB002 </s> A Review of Non-Invasive Haptic Feedback stimulation Techniques for Upper Extremity Prostheses <s> Vibration Feedback Display <s> The implementation of a sensory feedback system is particularly important in upper limb prosthesis to improve closed-loop control and prosthesis acceptance. Restoring the touch sensations of individual fingers becomes critical in increasing the sense of embodiment of the artificial limb. Vibrotactile feedback appears as a feasible route to provide useful sensory feedback to prosthesis users. Most studies evaluate the stimulation of the forearm as a potential location of the sensory feedback system. However, it is also necessary to evaluate the stimulation of the upper arm to provide feedback to above-elbow amputees. In this work, the ability of 30 able-bodied subjects to discriminate vibrotactile stimulations in the biceps was evaluated. Particularly, experiments were conducted to evaluate their ability to discriminate different stimulation sites and different stimulation patterns. Stimulation sites were associated to tactile feedback from individual fingers of a virtual hand whereas simulation patterns were associated to potential grasping configurations of the hand. To compare the results, the same experiments were performed on the forearm. The results showed that subjects discriminated finger’s tactile feedback with about 94% average accuracy and grasping pattern feedback with about 85% average accuracy. The special acuity observed in the upper arm suggests that vibrotactile stimulation may also provide suitable feedback for restoring tactile sensation in above elbow amputees. <s> BIB003
The vibration feedback display is the method of restoring the missing sensations of individual fingers to the patient's brain by utilizing diverse kinds of vibrational simulators, like linear electromagnetic actuators, rotary electromagnetic actuators and non-electromagnetic actuators BIB003 . For example, attaching wearable armbands equipped with four vibrating motors on the user's upper arm and forearm to convey information about collisions that occur on a 6-degreesof-freedom robotic arm has been studied  . A brief summary of works on vibration feedback display is presented in Table 2 . Fifteen participants (fourteen males and one female) are engaged in previous work BIB001 , in order to evaluate the performance of two different types of vibration stimulation display: the linear resonant actuators (LRAs) and the eccentric rotating masses (ERMs). The feedback system consists of nine stimulators from each actuator type, i.e., the LRA and ERM. From the obtained results, the authors concluded that LRAs are more useful than ERMs when dealing with binary information, and less power consumption, while the ERMs can be utilized for handover the complex signals. On the other hand, the vibration feedback stimulation display was used to train the patient on how to use his myoelectric prosthetic hand with high performance  . The haptic system was designed to increase the ability of the user to perform multitask with his prostheses within an acceptable accuracy. Five haptic rotative actuators were used to convey the contact pressure information of 14 (CZN-CP6) resistive pressure sensors. The experiments confirmed that the feedback mechanisms assisted the two patients of right hand missing to upgrade a cerebral automatism for usual movements and to respond in real time to multi external effects. The tactile feedback system consists of an FSR pressure sensor, 3D printer prosthetic hand, and shaft-less, small size, coin shaped vibration motors of 10 mm diameter are designed and developed in BIB002 , as shown in Fig. 5 . A. The main objective of the study is to implement the amputee a much response during holding and releasing objects. Stimulation sequences are used to make the amputee interacts with the environment comfortably. The sequences are high vibration during 0.5 sec at the instant of grasping and releasing the objects and periodically excitation in between to provide the user with sense that he is holding the object continuously. The behavior of the stimulation response when holding the empty bottle was shown in Fig. 5 . B. The results proved the effectiveness of the vibrotactile system to increase the ability of the prosthetic hand used to manipulate the objects of different sizes.