Analysis of the relationship between the rise-time and the amplitude of single-fibre potentials in human muscles

Using the core-conductor theory, a single fibre action potential (SFAP) can be expressed as the convolution of a biolectrical source and a weight function. In the Dimitrov¿Dimitrova (D¿D) SFAP convolutional model, the first temporal derivative of the intracellular action potential (IAP) is used as t...

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Detalles Bibliográficos
Autores: Rodríguez Falces, Javier, Navallas Irujo, Javier, Gila Useros, Luis, Rodríguez Carreño, Ignacio, Malanda Trigueros, Armando
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2010
País:España
Institución:Universidad Pública de Navarra
Repositorio:Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
OAI Identifier:oai:academica-e.unavarra.es:2454/55566
Acceso en línea:https://hdl.handle.net/2454/55566
Access Level:acceso abierto
Palabra clave:SFAP convolutional model
SFAP rise-time
IAP spatial profile
Core-conductor theory
Needle movement
Descripción
Sumario:Using the core-conductor theory, a single fibre action potential (SFAP) can be expressed as the convolution of a biolectrical source and a weight function. In the Dimitrov¿Dimitrova (D¿D) SFAP convolutional model, the first temporal derivative of the intracellular action potential (IAP) is used as the source. The present work evaluates the relationship between the SFAP peak-to-peak amplitude (Vpp) and peak-topeak interval (rise-time, RT) at different fibre-to-electrode distances using simulated signals obtained by the D¿D model as well as real recordings. With a single fibre electrode, we recorded 63 sets of consecutive SFAPs from the m. tibialis anterior of four normal subjects. The needle was intentionally moved whilst recording each SFAP set. We used the observed changes in RT and Vpp within each SFAP set as a point of reference with which to evaluate how closely the relationship between RT and Vpp provided by the D¿D model reflects real data. We found that half of the recorded SFAP sets had rise-times higher than those generated by the D¿D model. We also showed the influence of the IAP spatial length on the sensitivity of RT and Vpp with radial distance. The study reveals some inaccuracies in simulated SFAPs whose origin might be related to the assumptions made in the core-conductor theory.