Magnetna stimulacija mišice tibialis anterior

RWANKUBA, ALEX (author), Miklavčič, Damijan (mentor), Maček Lebar, Alenka (comentor)

V diplomski nalogi sem preučeval magnetno stimulacijo skeletnih mišic. Meritve sem opravil na mišici tibialis anterior (sprednja golenična mišica). Uporabljal sem magnetni stimulator TESLA-Stym (podjetja ISKRA MEDICAL d.o.o.). Meritve in testiranja sem izvedel na 20 zdravih prostovoljcih, od tega je bilo 11 moških in 9 žensk. V diplomski nalogi smo preučili tri področja. Prvič, ob draženju mišice tibialis anterior z uporabo magnetne stimulacije nas je pri različno nastavljenih frekvencah magnetnega polja zanimala izmerjena velikost navora v odvisnosti od časa. Navor smo merili na stopalu in predstavlja krčenje mišice tibialis anterior. Iskali smo tudi tetanično frekvenco. Rezultati so pokazali, da se tetanična frekvenca od posameznika do posameznika nekoliko razlikuje - do približno 5 Hz. Z natančno analizo smo na posamičnem primeru ocenili, da se tetanična frekvenca mišice tibialis anterior nahaja pri 40 Hz. Pri magnetni stimulaciji smo opazili široko razpršenost velikosti mišičnih odzivov med merjenci, ki so bili draženi z enakimi signali. To smo predpisali fiziološkim in biološkim razlikam med merjenci in naravi delovanja magnetne stimulacije. Nadalje sklepamo, da bi bila pri električni stimulaciji, kjer bi bili merjenci draženi z enakimi signali, razpršenost manjša. Drugič, primerjali smo velikost in vrsto bolečine med magnetno in električno stimulacijo mišice tibialis anterior. V ta namen so merjenci izpolnili McGillov vprašalnik bolečine. Podatke iz primerljivih merjenj pri draženju mišice tibialis anterior z uporabo električne stimulacije smo pridobili iz sorodne diplomske naloge kolega Miha Sužnika z naslovom »Ocena bolečine pri monofazni in bifazni električni stimulaciji«. Rezultati obeh diplomskih naloge kažejo, da je magnetna stimulacija manj boleča od električne stimulacije. Ocena bolečine VAS (ang. visual analog scale; lestvica od 0 do 10) je v povprečju pri magnetni stimulaciji znašala 1,4, pri električni stimulaciji pa, kot je zabeleženo v diplomski nalogi Miha Sužnika, 3,4. Opazili smo, da je pri magnetni stimulaciji velikost bolečine sorazmerna z velikostjo mišičnega odziva ob stimulaciji. Izmed 20 je 8 merjencev, ki so se na stimulacijo odzvali z večjim mišičnim odzivom od preostalih 12, v povprečju bolečino ocenilo kot 50% večjo. Od skupno 15 deskriptorjev - opisov tipa bolečine - je bila samo pri dveh deskriptorjih bolečina večja pri magnetni kot pri električni stimulaciji: deskriptor mehke bolečine in deskriptor udarjanja. Pri električni stimulaciji pa so v primerjavi z magnetno stimulacijo najbolj izstopali deskriptorji zbadanja, pečenja, in rezanja. Ti so bili pri magnetni stimulaciji ocenjeni z zelo nizkimi vrednostmi. Poleg omenjenih deskriptorjev sta bila dva zelo značilna (visoko ocenjena) tako pri magnetni kot pri električni stimulaciji. To sta streljanje in krč. Tretjič, ocenili smo največjo zmogljivost magnetnega stimulatorja TESLA-Stym, in sicer tako, da smo z njegovo uporabo skušali povzročiti čim večje mišično krčenje. Rezultat smo primerjali s posameznikovim največjim hotenim krčenjem iste mišice. V povprečju smo bili z uporabo magnetnega stimulatorja zmožni vzbuditi mišični odziv, ki je bil 14% tistega, ki smo ga izmerili pri največjem hotenem krčenju iste mišice.

• Language: Slovenian
• Keywords: magnetna stimulacija, električna stimulacija, merjenje bolečine, McGillov vprašalnik, TESLA-Stym, tetanična frekvenca
• Work type: Undergraduate thesis
• Organization: FE - Faculty of Electrical Engineering
• Year: 2015
• PID: 20.500.12556/RUL-30795
• Publication date in RUL: 15.05.2015

Secondary language

• Language: English
• Title: Magnetic stimulation of the tibialis anterior muscle

Abstract

In this diploma thesis I studied magnetic stimulation of skeletal muscles. Measurements were made on the tibialis anterior muscle. The magnetic stimulation was performed by means of TESLA-Stym device (produced by ISKRA MEDICAL d.o.o.). Measurements and tests were performed on 20 healthy volunteers, 11 males and 9 females. Within the thesis we studied three fields of interest. First, with magnetic stimulation of the tibialis anterior muscle at varying stimulating frequencies of the magnetic field, we observed the generated torque with respect to time. Torque was measured on the foot and it represents the contractions of the tibialis anterior muscle. We were also interested in finding the tetanic frequency. Results show that tetanic frequency varies from individual to individual up to about 5 Hz. We then analysed an individual case and determined the tetanic frequency of the tibialis anterior muscle to be at 40 Hz. In magnetic stimulation we noticed a wide dispersion of the sizes of muscle responses, although individuals were stimulated with the same signals. We attributed that to physiological and biological differences between individuals and to the principles behind how magnetic muscle stimulation works. We furthermore conclude that the dispersion would be smaller in using electrical stimulation where we would stimulate each individual with the same electric signal. Second, we compared the size and type of pain between magnetic and electrical stimulation. For this comparison we used McGill pain questionnaire. For information of comparable measurements, where the same muscle was stimulated by means of electrical stimulation, we looked into a related diploma thesis by colleague Miha Sužnik, entitled »Pain evaluation during monophasic and biphasic electrical stimulation«. Results show that magnetic stimulation is less painful than electrical stimulation. Average VAS (visual analog scale - from 0 to 10) pain score for magnetic stimulation was 1,4 and for electrical stimulation, as noted in Miha Sužnik's diploma thesis, 3,4. We observed that when we stimulated the muscle by means of magnetic stimulation, the experienced pain was directly correlated with the size of muscle response. 8 out of 20 volunteers, which responded to the stimulation with higher muscle response than the other 12, reported on average a 50% higher VAS pain score. Of 15 descriptors (describing type of pain), only two were reported as more painful in magnetic than in the electrical stimulation: descriptor of tender pain and descriptor of pounding. In electrical stimulation descriptors: piercing, burning and cutting are the most pronounced when compared with magnetic stimulation where they are graded with very low scores. Apart from the mentioned descriptors, two are very pronounced in both magnetic and electrical stimulation. These are shooting and cramping. Third, we evaluated the maximum capabilities of TESLA-Stym device, by trying to produce the highest muscle contraction possible. We compared the result with the individual's maximal voluntary contraction of the same muscle. On average we recorded that the muscle response we got by means of TESLA-Stym device was 14% of that of the maximal voluntary contraction of the same muscle.

• Keywords: magnetic stimulation, electrical stimulation, pain measurment, McGill questionnaire, TESLA-Stym, tetanic frequency, tetanus