A Survey on the Pain Threshold and Its Use in Robotics Safety Standards

Analyzing soft tissue stiffness of human upper arms during physical dynamic and quasi‐static impacts in human–machine interaction

“…In this study, the highest dynamic impact velocity of 0.7 m/s was selected because of the limitation in the sweep speed of the ultrasound device in the M‐mode. The pilot experiments also showed that participants felt pain at the impact location when the impact force exceeded 50 N. Despite the fact that ISO/TS15066 based on the University of Mainz study accepts a maximum permissible force of more than 50 N for the upper arm, a number of factors relating to the experimental setup and participant characteristics may affect the way pain onset is measured during physical contact (Mylaeus et al, 2019). Consequently, different studies may report different pain thresholds for different body locations.…”

“…In ISO/TS15066, the University of Mainz specifies the maximum permissible force for QS contact at 150 N for the deltoid muscle, but the same research team conducted other studies and determined a significantly lower pain threshold for the deltoid muscle (Melia et al, 2015, 2019). Additionally, this study used a dynamic impact velocity of 0.7 m/s for the pilot experiment, which might exceed the ability of soft tissues to deform, resulting in an inhomogeneous distribution of forces that may reduce the onset of pain (Mylaeus et al, 2019). Nevertheless, the University of Mainz conducted the experiments during QS contact and based on their findings specified the maximum permissible force for physical contact both during dynamic and QS contact.…”

“…Nevertheless, the University of Mainz conducted the experiments during QS contact and based on their findings specified the maximum permissible force for physical contact both during dynamic and QS contact. Furthermore, the material properties and the geometry of impactors also play a significant role in the measurement of pain thresholds (Mylaeus et al, 2019). A larger contact area of an impactor is associated with a higher pain threshold (Defrin et al, 2003; Povse et al, 2016).…”

“…A flat-ended cylinder with a diameter of 25 mm FL25 Figure 2a A flat-ended cylinder with a diameter of 10 mm FL10 Figure 2b A hemisphere with a diameter of 25 mm HS25 Figure 2c A cuboid with a 14 mm square end SQ14 Figure 2d F properties and the geometry of impactors also play a significant role in the measurement of pain thresholds (Mylaeus et al, 2019). A larger contact area of an impactor is associated with a higher pain threshold (Defrin et al, 2003;Povse et al, 2016).…”