The evaluation of the measurement uncertainty of a robust all-fiber-based low-coherence interferometer for the measurement of absolute thickness of transparent artifacts is described. The performance of the instrument is evaluated by measuring the length of air-gaps in specially constructed artifacts and the observed measurement errors are discussed in the context of the uncertainty associated ...

Physiological hand tremor and other manual positioning errors limit precision in microsurgical procedures. Our research has involved development of adaptive algorithms and neural network methods for real-time compensation of such errors. This paper presents a novel design for an active hand-held microsurgical instrument to implement these algorithms, particularly during vitreoretinal microsurge...

Surgical robots can improve the safety of minimally invasive surgeries through image guidance and motion filtering, but design choices that reduce patient trauma (e.g., thin instrument shafts) lead to intraoperative variation in kinematic parameters. The resulting kinematic errors can degrade image-guidance methods and cause instrument motions in undesired directions. This work addresses the mo...

Recent parameter matching methods for multiple wavetable synthesis have used a simple relative spectral error formula to measure how accurately the synthetic spectrum matches an original spectrum [1]. It is supposed that the smaller the spectral error, the better the match, but this is not always true. This paper describes a modified error formula, which takes into account the masking character...

The method of indirect least squares (ILS) using a proxy for a discrete instrument is shown to identify a weighted average of local treatment e¤ects. The weights are nonnegative if and only if the proxy is intensity preserving for the instrument. A similar result holds for instrumental variables (IV) methods such as two stage least squares. Thus, one should carefully interpret estimates for cau...