Interactions between the ventral premotor (PMv) and the primary motor cortex (M1) are crucial for transforming an object's geometrical properties, such as its size and shape, into a motor command suitable for grasp of the object. Recently, we showed that PMv interacts with M1 in a specific fashion, depending on the hand posture. However, the functional connectivity between PMv and M1 during the...

OBJECTIVE Pencil grasps other than the dynamic tripod may be functional for handwriting. This study examined the impact of grasp on handwriting speed and legibility. METHOD We videotaped 120 typically developing fourth-grade students while they performed a writing task. We categorized the grasps they used and evaluated their writing for speed and legibility using a handwriting assessment. Usi...

Robotic grasp detection task is still challenging, particularly for novel objects. With the recent advance of deep learning, there have been several works on detecting robotic grasp using neural networks. Typically, regression based grasp detection methods have outperformed classification based detection methods in computation complexity with excellent accuracy. However, classification based ro...

This paper presents a novel robot grasping planning approach that extracts grasp strategies (grasp type, and thumb placement and direction) from human demonstration and integrates them into the grasp planning procedure to generate a feasible grasp concerning the target object geometry and manipulation task. Our study results show that the grasp strategies of grasp type and thumb placement not o...

GRASP with path-relinking (GRASP+PR) is a metaheuristic for finding optimal or near-optimal solutions of combinatorial optimization problems. This paper proposes a new automatic parameter tuning procedure for GRASP+PR heuristics based on a biased random-key genetic algorithm (BRKGA). Given a GRASP+PR heuristic with n input parameters, the tuning procedure makes use of a BRKGA in a first phase t...

OBJECTIVE Recent studies have shown that dorsal premotor cortex (PMd), a cortical area in the dorsomedial grasp pathway, is involved in grasp movements. However, the neural ensemble firing property of PMd during grasp movements and the extent to which it can be used for grasp decoding are still unclear. APPROACH To address these issues, we used multielectrode arrays to record both spike and l...

A report of the General Robotics and Active Sensory Perception (GRASP) Laboratory. Comments University of Pennsylvania Institute for Research in Cognitive Science Technical Report No. IRCS-93-31. This other is available at ScholarlyCommons: http://repository.upenn.edu/ircs_reports/186

Tissue grasping is a crucial component of surgical procedures that involves simultaneously satisfying two competing criteria – maintaining grasp stability while avoiding damage due to excessive grip force. Automation of grasp force control thus requires a controller to apply grasping forces just sufficient to maintain grasp stability. This task is complicated by the serially connected dynamics ...

Power grasp is a grasp that can hold objects stably without changing the joint torques of ngers. Almost all studies on power grasp deal with one object. But it is more eÆcient to hold multiple objects at the same time. This paper derives a condition for power grasp for multiple objects, and de nes an optimal power grasp from the viewpoint of decreasing the work of joint torques. Lastly, we show...

This paper discusses the scale-dependent grasps. Suppose that an object is initially placed on a table without touching by human hand and, then he (or she) finally achieves an enveloping grasp after an appropriate approach phase. Under such initial and final conditions, human unconsciously changes the grasp strategy according to the size of object, even though they have similar geometry. We cal...