Pulse rate estimation using hydraulic bed sensor

We propose in this paper an effective method to obtain the pulse rate from a hydraulic sensor that is placed under the mattress. The sensor captures the superposition of the ballistocardiogram (BCG) and the respiration signals. The BCG is modeled as the j-peak with a frequency modulation component. The proposed method utilizes the Hilbert transform to effectively capture the j-peak, which allows the pulse rate information to come out distinctively in the frequency domain. Among the five subjects tested, the error in pulse rate estimation is less than 1%.

Detection of spinal ataxia in horses using fuzzy clustering of body position uncertainty

REASONS FOR PERFORMING STUDY

Subjective neurological evaluation in horses is prone to bias. An objective method of spinal ataxia detection is not subject to these limitations and could be of use in equine practice and research.

HYPOTHESIS

Kinematic data in the walking horse can differentiate normal and spinal ataxic horses.

METHODS

Twelve normal and 12 spinal ataxic horses were evaluated by kinematic analysis walking on a treadmill. Each body position signal was reduced to a scalar measure of uncertainty then fuzzy clustered into normal or ataxic groups. Correct classification percentage (CCP) was then calculated using membership values of each horse in the 2 groups. Subsequently, a guided search for measure combinations with high CCP was performed.

RESULTS

Eight measures of body position resulted in CCP > or = 70%. Several combinations of 4-5 measures resulted in 100% CCP. All combinations with 100% CCP could be obtained with one body marker on the back measuring vertical and horizontal movement and one body marker each on the right fore- and hindlimb measuring vertical movement.

CONCLUSIONS AND POTENTIAL RELEVANCE

Kinematic gait analysis using simple body marker combinations can be used objectively to detect spinal ataxia in horses.