Title :
Parameter estimation of human nerve C-fibers using matched filtering and multiple hypothesis tracking
Author :
Hammarberg, Björn ; Forster, Clemens ; Torebjörk, Erik
Author_Institution :
Dept. of Signals & Syst., Uppsala Univ., Sweden
fDate :
4/1/2002 12:00:00 AM
Abstract :
We describe how multiple-target tracking may be used to estimate conduction velocity changes and recovery constants of human nerve C-fibers. These parameters discriminate different types of C-fibers and pursuing this may promote new insights into differential properties of nerve fiber membranes. Action potentials (APs) were recorded from C-fibers in the peroneal nerve of awake human subjects. The APs were detected by a matched filter constituting a maximum-likelihood constant false-alarm rate detector. Using the multiple-hypothesis tracking method and Kalman filtering, the detected AN (targets) in each trace (scan) were associated to individual nerve fibers (tracks) by their typical conduction latencies in response to electrical stimulation. The measurements were one-dimensional (range only) and the APs were spaced in time with intersecting trajectories. In general, the AP amplitude of each C-fiber differed for different fibers. Amplitude estimation was therefore incorporated into the tracking algorithm to improve the performance. The target trajectory was modeled as an exponential decay with three unknowns. These parameters were estimated iteratively by applying the simplex method on the parameters that enter nonlinearly and the least squares method on the parameters that enter linearly.
Keywords :
Bayes methods; Kalman filters; bioelectric potentials; iterative methods; least squares approximations; matched filters; medical signal processing; neurophysiology; parameter estimation; probability; tracking filters; Kalman filtering; action potentials; amplitude estimation; conduction velocity changes; exponential decay; human nerve C-fibers; least squares method; matched filtering; maximum-likelihood constant false-alarm rate detector; microneurography; multiple hypothesis tracking; multiple-target tracking; parameter estimation; peripheral fibers; recovery constants; simplex method; spike sorting; stimulus-response characteristics; Biomembranes; Detectors; Filtering; Humans; Matched filters; Maximum likelihood detection; Maximum likelihood estimation; Nerve fibers; Parameter estimation; Target tracking; Action Potentials; Algorithms; Humans; Likelihood Functions; Nerve Fibers; Neural Conduction; Peroneal Nerve; Signal Processing, Computer-Assisted;
Journal_Title :
Biomedical Engineering, IEEE Transactions on