Methods and instrumentation for assessment of motor function by the means of electromyography

Metoda merenja i analize električnih potencijala snimljenih površinskim elektrodama sa skeletnih mišića naziva se elektromiografija. Primenom ove metode omogućeno je praćenje mišićne i nervne aktivnosti, a samim tim omogućena je i direktna ocena motornog i indirektna ocena senzornog sistema. Cilj istraživanja je usavršavanje tehnologije merenja i analize elektromiografskih signala koje bi omogućile razvoj novih modela u senzorno-motornom sistemu čoveka. Novorazvijeni sistem, koji je prikazan u ovoj disertaciji, ima dve osnovne namene: podrška bazičnim istraživanjima u domenu neuronauka i podrška kliničkom radu. Prikazana je efikasnost sistema u oceni senzorno-motornog statusa kod pacijenata koji su preživeli moždani udar. Kroz 2 prilaza u merenju i analizi elektromiografskih signala prikazano je kako se može oceniti status senzorno-motornog sistema kod zdravih i kod pacijenata. Prvi prikaz se sastoji u proučavanju spontane mišićne aktivnosti tokom kontrolisanog voljnog pokreta članka i tokom hoda. Ovaj prikaz je iskorišćen za proučavanje kratkoročnih i dugoročnih efekata terapije na senzorno-motorni oporavak pacijenata. Drugi prikaz se sastoji iz proučavanja evociranih motornih potencijala. Na primeru zdravih ispitanika pokazano je kako se na pouzdan i ponovljiv način može iskoristiti projektovana instrumentacija za ocenu senzornomotornog sistema. U analizi mišićnih signala predstavljene su dve nove metode proučavanja spontanih i evociranih potencijala mišića. Za potrebe ocene spontane mišićne aktivnosti uvedene su nove mere kokontrakcije koje omogućavaju ocenu mišićnih aktivacija i koje omogućavaju istovremenu ocenu vremenskih i amplitudskih osobina signala. U oceni evociranih potencijala uvedeni su novi algoritmi za automatsko upravljanje električnom stimulacijom i akvizicijom signala, kao i novi vid vizuelizacije i ocene prostorne raspodela evociranih potencijala. Klinička primena projektovanog mernog sistema i V procedura merenja i analize elektromiografskih signala ima poseban značaj jer omogućuje praćenje oporavka u procesu rehabilitacije i može da pomogne u izboru terapijskih modaliteta. Funkcionalna mera oporavka koja se zasniva na elektromiografiji ima zadatak da bude dopuna konvencionalnim kliničkim skalama koje u većini slučajeva nisu dovoljno osetljive da bi ukazale na izvore patologija i na promene stanja pacijenta tokom lečenja.Electromyography is a method for measurement and analysis of electrical potentials of muscles in human. Nervous and muscular systems in humans can be assessed by the means of electromyography. This assessment enables direct evaluation of motor status, and indirect evaluation of sensory status. The aim of this research is the development of new technologies for measurement and analysis of electromyography signals, which would enable design of new sensory-motor models. The novel system, presented in this dissertation, has two main purposes: to improve research methodology in basic neurosciences and to support clinical practice. The functioning of the system is presented for the assessment of sensory-motor recovery in stroke patients. Two main approaches are used in measurement and analysis of electromyography signals in healthy subjects and in patients. The first approach consists of studying voluntary contractions by the means of electromyography during ankle movement and during gait. This approach is used for the studying long-term and short-term therapy effects on sensory-motor system during rehabilitation process in stroke patients. The second approach enables measurement and analysis of evoked motor potentials. Reliability and reproducibility of a designed instrumentation for assessment of motor status by studying evoked motor potentials is presented in healthy subjects. Two new methods for the analysis of voluntary muscle contraction and evoked potentilas are presented. For studying voluntary muscle contraction, the cocontraction measurement was introduced. These parameters reflected amplitude and temporal characteristics of recorded signals. For the analysis of evoked motor potentials new algoritms for the control of electrical stimulation and acquisition are presented. The novel method for vizualisation and assessment of spatial distribution of evoked potential is designed for the purposes of sensory-motor assessment. Clinical applications of the designed instrumentation, measurement procedures and analysis of electromyography VII signals have an impact in modern clinical practice. It enables assessment of recovery progress and rehabilitation procedures. Developed functional measurement of recovery by the means of electromyography should be used as an additional assessment method to stadard clinical scales, since in most cases those scales have less sensitivity in studying senzory-motor status than functional measurements