This article presents implementation and evaluation of a haptic playback system using the PHANToM haptic interface, in the context of our Virtual Haptic Back Project at Ohio University. Playback has the potential to improve virtual palpatory diagnosis training by allowing students to follow and feel an expert’s motions prior to performing their own palpatory tasks. We have two modes in our play...

PURPOSE To develop a realistic yet flexible 4D digital phantom based on patient anatomy for dynamic estimation of organ doses due to external ionizing radiation. METHODS In this work, we propose to build a 4D digital phantom based on patient CT anatomy and time-tagged CT information. A regional 4D-CT is first acquired on the patient around lesion with a RPM system. By binning CT information a...

This paper presents design and development of virtual objects to be used with haptic device PHANTOM Omni for motor rehabilitation by incorporating visual and haptic feedback. Developed predominantly for augmentation of motor skill of patient, the objects could also be used for teaching and enhancing writing skill of children. The virtual objects include English alphabets, numbers, string and ma...

OBJECTIVES To assess the feasibility of an objective approach for the evaluation of low-contrast detectability in multidetector computed-tomography (MDCT) by combining a virtual phantom containing simulated lesions with an image quality metric. MATERIALS AND METHODS A low-contrast phantom containing hypodense spheric lesions (-20 HU) was scanned on a 64-slice MDCT scanner at 4 different dose ...

Accurate sound speed estimates are desirable in a number of fields. In an effort to increase the spatial resolution of sound speed estimates, a new method is proposed for direct measurement of sound speed between arbitrary spatial locations. The method uses the sound speed estimator developed by Anderson and Trahey. Their least squares fit of the received waveform's curvature provides an estima...

An approach to enhance navigation task performance is to integrate sensory guidance (virtual fixtures) into a virtual training system. To evaluate the effects of adding virtual fixtures to skill acquisition, 32 subjects were required to use a PHANToM input device, to transport a virtual object through a computer generated 3-D graphic maze. Subjects practiced navigation under 4 conditions: the m...

This paper addresses issues affecting the implementation of a networked Hapto-Acoustic Virtual Reality Environment. This is a Virtual Reality system which combines 3D graphics visualisation, audio and touch interaction and which aims to produce a perceived real time interaction by the user with a computer generated model. Networking systems together makes it possible to collaborate in the virtu...

A case study based on both simulated and actual images was performed. The simulated anatomical phantom used was obtained from CT data of a human leg provided by the “Visible Human” project. A virtual orthopedic nail was added to the data set and projection images were obtained using a simulated irradiation procedure. An actual phantom made of wax having an orthopedic nail inserted was also imag...

The versatility and real-time imaging capability of commercial linear array transducers make them widely used in clinical ultrasound and photoacoustic imaging. However, they often suffer from limited detection view. For instance, acoustic waves traveling at a grazing angle to the transducer surface are difficult to detect. In this letter, we propose a simple and easy approach to ameliorate this...

In the recent years there have been various problems in medical treatments, of which the human error by the surgeon in an operation. In order to minimize the human error in an operation, we need a medical training system by which an inexperienced surgeon can try operating again and again to improve his skill. In our research, we set a goal to construct the medical training system, and in this p...