An empirical model of end-tidal CO(2) response to minute ventilation.

This paper presents an empirical model of end-tidal CO(2) (P(ET)CO(2)) response to minute ventilation (MV) for use in the closed-loop control of artificial respiration. An affine model structure consisting of a linear dynamic system followed by an affine transform is presented. It is proposed that this derives a low-order, high-fidelity representation of the respiratory process that can describe the positive and inversely proportional relationship between P(ET)CO(2) and MV.

Towards detecting surgical clips in 3D ultrasound for target localization in radiation therapy: a study on tissue phantoms.

A study is performed to measure the visibility of small surgical clips in 3D ultrasound volumes of a phantom as the first step towards using such clips as fiducial markers in radiation therapy. Visibility is calculated as the contrast to noise ratio of the echo from the clip to the background. The appearance of a resonance tail is also calculated using a moment analysis.