A Review of Non-Invasive Haptic Feedback stimulation Techniques for Upper Extremity Prostheses <s> Thermal Feedback Display <s> We propose a thermal display that can present a sudden temperature change using spatially divided warm and cold stimuli; the display exploits two characteristics of human thermal perception: the spatial resolution of thermal sensation is low, and the thermal threshold depends on the adapting temperature. Experimental results confirmed that users perceived separate individual thermal stimuli as a single stimulus when the thermally stimulated area was small because of the low spatial resolution. The spatially distributed warm and cold stimuli enabled users to perceive the thermal sensation rapidly even if the cold stimulus was suddenly presented after the warm stimulus and vice versa. Furthermore, our thermal display successfully made the skin more sensitive to both warm and cold stimuli simultaneously by using spatially divided warm and cold stimuli, each of which separately adjusts the adapting temperature. <s> BIB001 </s> A Review of Non-Invasive Haptic Feedback stimulation Techniques for Upper Extremity Prostheses <s> Thermal Feedback Display <s> This paper describes the design and control of a water-based multimodal haptic display. The system is able to provide temperature and pressure (pulse) cues through a finger-sized display. Temperature feedback is obtained by mixing hot and cold water stored in two water tanks. The heating and cooling of the water is performed with a Peltier whose two surfaces are used, thus increasing the energetic efficiency of the system. Mixing the hot and cold water allows for very rapid temperature changes essential in applications such as object discrimination. The device can provide cooling rates sufficient to mimic the contact with any object found in our daily lives. Tactile (pulse) feedback is achieved by closing the circuit with a valve while building up the pressure with the pump. Results show that temperature is controlled with a precision of ±1°C in the range of 20°C to 40°C while simultaneously generating sensible pulses. In addition, this display is MRI-compatible as it is remotely actuated using water. These characteristics make the system suitable for psychophysics experiments, which are considered to be one of the goals and the next logic step of this work. <s> BIB002 </s> A Review of Non-Invasive Haptic Feedback stimulation Techniques for Upper Extremity Prostheses <s> Thermal Feedback Display <s> Abstract The growing complexity of telemanipulation tasks calls for increased realism and intuitiveness of the interaction between the user and the master control. Humans perceive multiple haptic features of an object such as its stiffness, temperature, and shape, and rely on this multimodal information to achieve dexterous manipulation. However, to date, remote manipulators rarely provide haptic information to the operator. Moreover, current multimodal displays are often too rigid and bulky to be integrated into the manipulator. Thus, to improve the quality of teleoperation, there is a high demand for flexible devices that are capable of matching the skin's curvature while delivering multimodal haptic information to the operator. In this paper, we present a flexible tactile display delivering tactile and thermal stimuli to the user’s skin. We propose a hybrid electromagnetic-pneumatic actuation to operate a 2 × 2 array of tactile cells. Each cell provides a repetitive stimulation with a force and an indentation that are above the human perception threshold for the finger, palm, and forearm. In addition, the temperature of the display’s surface is controlled using a Peltier element attached to an air-cooled heatsink. By providing a reproducible cooling gradient, our display simulates common materials encountered in the daily environment. User study results show that (1) the tactile stimulation is perceived well and (2) the identification rates of objects simulated with the display were comparable to those obtained with real objects. Unlike previous devices, the thermal stimulation is delivered while the display is in constant contact with the user’s skin, a necessary requirement for teleoperation. These results demonstrate the potential of our device as a promising tactile display for providing haptic feedback in teleoperation. <s> BIB003 </s> A Review of Non-Invasive Haptic Feedback stimulation Techniques for Upper Extremity Prostheses <s> Thermal Feedback Display <s> This study discusses a feedback of temperature sensation for myoelectric prosthetic hand users. First, when the myoelectric prosthetic hand touches an object, the object temperature is detected by a temperature sensor installed on a fingertip. However, since the response of the temperature sensor is late, a temperature prediction algorithm is proposed. The identification of a transfer function of the temperature sensor was executed and temperature prediction is performed by using the identified transfer function. As a result, the temperature can be estimated in few seconds. Second, a feedback device of temperature sensation was developed using the Peltier element, which is mounted on the upper arm of a user. Third, the difference between the temperature sensation on the fingertip and upper arm was investigated. Then, when the user touches an object using the myoelectric prosthetic hand, the temperature at the fingertip is estimated using the temperature prediction algorithm, and the feedback device produces the corresponding temperature sensation in the upper arm. Thus, the user can sense the object temperature in the upper arm. Finally, an experiment to distinguish among five different temperatures was performed using the myoelectric prosthetic hand to verify the effectiveness of the developed feedback device. <s> BIB004
The thermal feedback display is the method of conveying the thermal information of the grasping objects to the amputees of upper limb mutilation. Thus, the amputees will be able to recognize multi-information about the surfaces and bodies by depending on the difference in temperatures and the heat flux between the objects and the tactile prosthetic hand. Indeed, there are different geometrical properties of each material, such as heat capacity and thermal conductivity that affect directly on the thermal feeling. For example, a healthy human can distinguish between two objects of different material located in the same environment, i.e. both objects have the same temperature BIB003 . Therefore, this type of haptic display is called thermal feedback display but not temperature feedback display, because the feeling is depending on the object's thermal properties but not only on its temperature degree. Table 6 lists the works in thermal feedback display. An extensive study associated with helping the amputees to recover the thermal sensation in high response and accuracy was presented in BIB004  . The main objective of these studies is to restore the thermal sensation by using low price equipment and solve its technical problems. Firstly, the low response problem of the K type (AD-1214) thermocouple temperature sensor was solved by proposing a new temperature prediction algorithm technique, in which the temperature can be estimated within few seconds. Secondly, the thermocouple temperature sensor with the temperature prediction algorithm technique was used to control the temperature of the rectangular Peltier element, which is a semiconductor device with two faces, and is competent to transfer heat flux from one side to the other. Consequently, the instability behavior of the Peltier element, especially when the operation time exceeds 5 sec, was analyzed. The evaluation experiment of the thermal feedback stimulation device has been conducted with ten healthy volunteers, myoelectric prosthetic hand, and five levels of temperature variations. The five temperature levels are: hot (approximately o C). For ten participants, the temperature distinction evaluation tests achieved the average success rate of 88%. The main issue of the Peltier element is that high respone time is required when changing its surfaces from warm state to the cool state or vice versa. Therefore, four Peltier devices have been arranged in a matrix form BIB001  , as discribed in Fig. 9 . Thus, the elements were configurated to enable rapid temporal change of temperature, since each of two opposite elements was programmed to work independently, with two elements for cooling the skin and the other two elements were utilized for the warming sensation. Two thermistor temperature sensors were used to build a feedback control loop, in order to control the temperature of the Peltier elements and inhibit over cooling and warming during thermal feedback. The recognition time of variation of temperature was improved by 36% on average, in comparison with using one Peltier element. Finally, a novel Thermo-tactile Multimodal Display was designed and developed BIB002 . The haptic device consists of a Peltier cell with two heat exchangers attached on its surfaces, for cooling down and warming up the water and collecting it in two separated containers. The warm and cool water were pumped to the haptic device and mixed together in different proportions to convey the required thermal sensation to the skin of user. The device was designed to provide temperature sensation within the range of 20°C to 40°C. Consequently, the evaluation results concluded that the design concept of the haptic device with very high-temperature variations response allows it to simulate the contact with many bodies found in our daily environment. 