Biomimetic finger control by filtering of distributed forelimb pressures.

A linear filter was developed for decoding finger commands from volitional pressures distributed within the residual forelimb. Filter parameters were based on dynamic pressures recorded from the residual limb within its socket, during specific finger commands. A matrix of signal features was derived from eight-dimensional (8-D) pressure vectors, and its pseudoinverse comprised the filter parameters.

Spectral analysis of heart variability in the newborn infant.

We investigated the relationship between spectral power and both mean heart rate (HR) and heart rate variability (HRV). Spectral power was calculated using digital heart rate recordings from term infants. Regression analysis revealed a positive correlation between low-frequency (LF) sympathetic power and HR, and a negative correlation between high-frequency (HF) parasympathetic power and HR.

Spectral analysis of heart rate variability in premature infants with feeding bradycardia.

An elevated level of baseline parasympathetic activity was noted in a group of premature infants suffering from bradycardia during feeding. At approximately 34 wk post-conceptional age, the heart rates of 12 infants with feeding bradycardia (birth weight = 1539 +/- 279 g; gestational age = 31.0 +/- 1.

Recognition of individual heart rate patterns with cepstral vectors.

Heart rate patterns may contain diagnostic as well as forensic information. To test these possibilities, individual heart rate patterns were represented as heart-rate cepstral vectors (HRCVs) computed in 12 dimensions via linear predictive coding (LPC) of brief segments of heart rate. A library of codebook vectors was computed for 12 cardiac patients from a standard ECG database.

The role of thermal feedback in electrosurgical tissue heating.

Thermal dependence of tissue resistivity was incorporated into a compartmental tissue model that predicted the interaction between power delivery from electrosurgical units (ESUs) and tissue heating. Simulations showed that as tissue resistance declines with heating, a positive feedback loop from tissue to generator is created that can promote alternate site burning. This study describes how the thermal behaviour of tissue resistance influences the output of microprocessor-controlled thermal generators, especially when used in the monopolar mode.