Marco Aggravi, PhD

In a proof-of-concept study, we aimed to verify whether the wearable haptic anklets, a device that delivers personalized suprathreshold alternating exteroceptive stimulation at the anklets on demand, may improve the quality of walking, including the freezing of gate (FOG), in idiopathic Parkinson’s disease (PD) patients. The clinical relevance of the presented device as a walking pacemaker to compensate the disturbed locomotion through the generation of a more physiological internal walking rhythm should be verified in a dedicated clinical trial. We tested 15 patients diagnosed as idiopathic PD, during their regular treatment regimen. Patients were evaluated during walking with the device switched on and off, personalized at their most comfortable cadence. Stride velocity, variance, and length, as well as FOG episode duration during walking or turning of 180°, were quantified by an optical high-performance motion capture VICON system. The alternating, rhythmic, sensory stimulation significantly improved either walking velocity or reduced inter-stride variance. Effects were more variable on stride length. The significant reduction of FOG episodes’ duration correlated with clinical severity of scales rating gate and balance. No safety problems occurred. The WEARHAP-PD device, whose Technology Readiness Level (TRL) is 6, significantly improved some walking abilities (walking velocity and stride variance) and reduced the duration of FOG episodes in idiopathic PD patients. Unlike the traditional auditory and visual explicit cues that require the user’s allocation of attention for correct functioning, the interaction of the patients with the surrounding environment was preserved, due to the likely implicit processing of haptic stimuli.

@article{RoLiAg-NEUR2020,
Title = {{Wearable haptic anklets for gait and freezing improvement in Parkinson’s disease: a proof-of-concept study}},
Author = {Rossi, Simone and Lisini Baldi, Tommaso and Aggravi, Marco and Ulivelli, Monica and Cioncoloni, David and Niccolini, Viola and Donati, Lorenzo and Prattichizzo, Domenico},
Journal = {Neurological Sciences},
Publisher = {Springer},
Pages = {0},
Year = {2020},
DOI = {https://doi.org/10.1007/s10072-020-04485-4}
}

We present a haptic teleoperation system capable of steering flexible needles under ultrasound imaging toward a target. With respect to similar works, this approach enables intuitive control of the needle motion while providing the user with 3D navigation and needle tip cutting force using a combination of kinesthetic and vibrotactile haptic feedback. The needle is tracked during the insertion using a 3D ultrasound probe. A friction estimation algorithm extracts salient information about the cutting force at the needle tip from a force sensor placed at the needle base. A grounded haptic interface enables natural 6-DoF control of the needle motion while providing kinesthetic feedback, and a wearable cutaneous interface on the forearm provides distributed vibrotactile sensations. We carried out a human subject study to validate the insertion system in a gelatine phantom and compare seven different feedback techniques. The best performance was registered when providing navigation cues through kinesthetic feedback and needle tip cutting force through cutaneous vibrotactile feedback. In this modality, results showed an 87% accuracy improvement with respect to providing no haptic feedback at all.

@article{AgEsKrMiPa-RAL2021,
Title = {{Haptic teleoperation of flexible needles combining 3D ultrasound guidance and needle tip force feedback}},
Author = {Aggravi, Marco and Estima, Daniel AL and Krupa, Alexandre and Misra, Sarthak and Pacchierotti, Claudio},
Journal = {IEEE Robotics and Automation Letters},
Publisher = {IEEE},
Pages = {0},
Year = {2021},
DOI = {https://doi.org/10.1109/LRA.2021.3068635}
}