This paper presents the Treadport Active Wind Tunnel (TPAWT)-a full-body immersive virtual environment for the Treadport locomotion interface designed for generating wind on a user from any frontal direction at speeds up to 20 kph. The goal is to simulate the experience of realistic wind while walking in an outdoor virtual environment. A recirculating-type wind tunnel was created around the pre-existing Treadport installation by adding a large fan, ducting, and enclosure walls. Two sheets of air in a non-intrusive design flow along the side screens of the back-projection CAVE-like visual display, where they impinge and mix at the front screen to redirect towards the user in a full-body cross-section. By varying the flow conditions of the air sheets, the direction and speed of wind at the user are controlled. Design challenges to fit the wind tunnel in the pre-existing facility, and to manage turbulence to achieve stable and steerable flow, were overcome. The controller performance for wind speed and direction is demonstrated experimentally.
Robotic surgical tools used in minimally invasive surgeries (MIS) require miniaturized and reliable actuators for precise positioning and control of the end-effector. Miniature pneumatic artificial muscles (MPAMs) are a good choice due to their inert nature, high force to weight ratio, and fast actuation. In this paper, we present the development of miniaturized braided pneumatic muscles with an outer diameter of ∼1.2 mm, a high contraction ratio of about 18%, and capable of providing a pull force in excess of 4 N at a supply pressure of 0.8 MPa. We present the details of the developed experimental setup, experimental data on contraction and force as a function of applied pressure, and characterization of the MPAM. We also present a simple kinematics and experimental data based model of the braided pneumatic muscle and show that the model predicts contraction in length to within 20% of the measured value. Finally, a robust controller for the MPAMs is developed and validated with experiments and it is shown that the MPAMs have a time constant of ∼10 ms thereby making them suitable for actuating endoscopic and robotic surgical tools.
This paper presents a compliant end-effector that cuts soft tissues and senses the cutting forces. The end-effector is designed to have an upper threshold on cutting forces to facilitate safe handling of tissue during automated cutting. This is demonstrated with nonlinear finite element analysis and experimental results obtained by cutting inhomogeneous phantom tissue. The cutting forces are estimated using a vision-based technique that uses amplified elastic deformation of the compliant end-effector. We also demonstrate an immersive tele-operated tissue-cutting system together with a haptic device that gives real-time force feedback to the user.
Bell’s palsy is an acute unilateral facial palsy of the lower motor neuron type predominantly affecting middle aged men. Although exact aetiology is unknown but probable causes include entrapment of the nerve at the mental foramen and vasospasm due to external factors. Surgical management along with medical management provides an assuring relief for the Bell’s palsy sufferers, may produce adverse effects such as facial nerve palsy or post-surgical synkinesis. Homoeopathic medicines, when selected based on signs and symptoms, act on the vital force dynamically and gently restore the nerve functioning to normal. Here, we present a case of left-sided Bell’s palsy recovered with homoeopathic medicines prescribed on the basis of causation and side affinity. The recovery was assessed by the House Brackmann scale and the quality of life was assessed using the modified Naranjo criteria.
We present a new feature for endoscopy wherein an endoscopist can palpate to assess abnormalities during the procedure and can experience the visual and haptic playback of the procedure later on when the patient returns. In our prototype, tactile sensors mounted on the endoscope help gather the force information, which is not only displayed to the practitioner but is also stored for later use. The recorded event that includes the video and the force data can be accessed using an endoscopic haptic simulator to re-create the experience for the clinician to help in diagnosis and treatment. We demonstrate our concept with a 2D setup shown in the attached figure, which comprises a scaled stomach model, a Falcon robot augmented with a tactile sensor, and a second Falcon to play the event back. Finite element analysis is integrated within the haptic loop. The recorded path is displayed to guide the user.
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