Fattori di variabilità dei dati

Poiché a seguito dell'analisi dei dati è stata riscontrata una moderata variabili- tà, sono state eettuate indagini visive al microscopio ed ulteriori misurazioni. Per valutare eventuali dierenze dovute alla variabilità nei processi di microfab- bricazione, sono state confrontate le impedenze medie dei siti di stimolazione e recording per wafer diversi.

L'impedenza media dei siti di stimolazione del wafer A è di 98.01 ± 32.59

kΩ mentre per il wafer B l'impedenza è sui 54.52 ±15.84 Ω. I siti di recording

hanno un'impedenza media di 214.28 ± 55.6 kΩ per il wafer A e di 125.7 ±

52.31 kΩ per il wafer B (g. 4.7).

Le dierenze percentuali per entrambi i tipi di siti, seppur non statistica- mente signicative (p>0.05, Kruskal Wallis), spaziano dal 41% al 46%. Ciò può essere legato a difetti sulla supercie dei siti (g. 4.8(b))e a dierenti du- rate dei trattamenti di attacco della PI per i diversi wafer. Dall'analisi ottica infatti risulta che in alcuni siti sono presenti residui di polimmide, i quali isola- no parzialmente la supercie del sito, aumentandone l'impedenza. Inoltre, altri siti sono andati incontro a processi di delaminazione (g. 4.8(c)), mostrando alti valori di impedenza. La causa può essere ricercata nel processo di deposi- zione dei metalli: impurità sul wafer prima della deposizione, distribuzione non omogenea del metallo, dierenti trattamenti per aumentare la rugosità della PI. Si suppone quindi che, perfezionando le tecniche di microfabbricazione, si possano ottenere impedenze più costanti al variare del wafer di riferimento.

(a) Sito con PI non del tutto rimossa (b) Sito con difetti superciali

(c) Siti delaminati

Conclusioni

Con il presente lavoro di tesi si mira a dimostrare la realizzabilità di un elet- trodo intramuscolare essibile che presenti una geometria tridimensionale ri- petibile, in modo da assicurare un adeguato ancoraggio ed una più ampia area campionata rispetto agli attuali elettrodi intramuscolari.

L'obiettivo è stato conseguito attraverso la microfabbricazione di un elet- trodo in polimmide, con parti conduttive in oro. L'elettrodo è poi stato carat- terizzato elettricamente, elettrochimicamente e meccanicamente, misurando una resistenza ohmica delle tracce in media pari a 120.68 Ohm, in accordo con i valori teorici stimati. L'impedenza media misurata ad 1 kHz è di 60.11 kOhm per i siti di stimolazione e di 131.07 kOhm per i siti di registrazione, coerentemente con i valori di impedenza dell'elettrodo intramuscolare a lm sottile 2D realizzato in precedenti lavori [72]. Durante la prova di trazione, l'elettrodo ha esibito una resistenza a rottura di circa 0.85 N, ovvero quasi un ordine di grandezza superiore alla forza di inserimento nel muscolo, stimata in base ai valori ricercati in letteratura. La biocompatibilità dei materiali è già stata vericata durante impianti cronici in nervo sciatico di ratto [82].

Per una più completa caratterizzazione, si potranno eettuare dei test ex vivo per valutare la funzionalità dell'elettrodo e la qualità dell'ancoraggio. Ul- teriori test in vivo andranno eseguiti per stabilire la procedura ottimale di impianto, per confrontare le prestazioni rispetto ad altri elettrodi e vericarne la longevità. Si potrebbe poi ottimizzare il design in modo da evitare l'in- tervento chirurgico, come per gli elettrodi a lo. Inne, vi potrebbero essere integrate delle componenti elettroniche in modo da abolire i li percutanei, ispirandosi agli IMES, rispetto a cui l'elettrodo risulterebbe più compliante e selettivo.

Bibliograa

[1] Y. Shimada, K. Sato, H. Kagaya, N. Konishi, S. Miyamoto, and T. Matsunaga, Clinical use of percutaneous intramuscular electrodes for functional electrical stimulation, Archives of Physical Medicine and Rehabilitation, vol. 77, no. 10, pp. 10141018, 1996.

[2] J. Chae, D. T. Yu, M. E. Walker, A. Kirsteins, E. P. Elovic, S. R. Flanagan, R. L. Harvey, R. D. Zorowitz, F. S. Frost, J. H. Grill, and Z.- P. Fang, Intramuscular Electrical Stimulation for Hemiplegic Shoulder Pain, American Journal of Physical Medicine & Rehabilitation, vol. 84, no. 11, pp. 832842, 2005.

[3] R. J. Mobbs, S. Nair, and P. Blum, Peripheral nerve stimulation for the treatment of chronic pain, Journal of Clinical Neuroscience, vol. 14, no. 3, pp. 216221, 2007.

[4] N. Jiang, J. L. Vest-Nielsen, S. Muceli, and D. Farina, EMG-based simultaneous and proportional estimation of wrist/hand dynamics in uni-Lateral trans-radial amputees, Journal of NeuroEngineering and Rehabilitation, vol. 9, no. 1, p. 42, 2012.

[5] R. Kleissen, J. Buurke, J. Harlaar, and G. Zilvold, Electromyogra- phy in the biomechanical analysis of human movement and its clinical application, Gait & Posture, vol. 8, no. 2, pp. 143158, 1998.

[6] S. Micera, J. Carpaneto, and S. Raspopovic, Control of hand prosthesis using peripheral information, Biomedical Engineering, IEEE Reviews in, vol. 3, pp. 4868, 2010.

[7] S. Micera, C. Carrozza, L. Beccai, F. Vecchi, and P. Dario, Hybrid bionic systems for the replacement of hand function, Proceedings of the IEEE, vol. 94, no. 9, pp. 17521761, 2006.

[8] S. Amsuess, P. Goebel, B. Graimann, and D. Farina, Extending mode switching to multiple degrees of freedom in hand prosthesis control is not ecient, pp. 658661, 2014.

[9] S. Bouisset and B. Maton, Quantitative relationship between surface EMG and intramuscular electromyographic activity in voluntary move- ment, American Journal of Physical Medicine & Rehabilitation, vol. 51, no. 6, pp. 28595, 1972.

[10] J. Perry, C. E. Schmidt, and D. J. Antonelli, Surface Versus Intramuscu- lar Electrodes for Electromyography of Supercial and Deep Muscles, Physical Therapy, vol. 61, no. 1, pp. 715, 1981.

[11] A. Cutrone, J. D. Valle, D. Santos, J. Badia, C. Filippeschi, S. Micera, X. Navarro, and S. Bossi, A three-dimensional self-opening intraneural peripheral interface (SELINE), Journal of Neural Engineering, vol. 12, no. 1, p. 016016, 2015.

[12] M. Pozzo, D. Farina, and R. Merletti, Electromyography: Detection, processing, and applications., in Biomedical technology and devices handbook (C. Press, ed.), ch. 4, 2004.

[13] M. Ortiz-Catalan, R. Brånemark, B. Håkansson, and J. Delbeke, On the viability of implantable electrodes for the natural control of articial limbs: Review and discussion, BioMedical Engineering OnLine, vol. 11, no. 1, p. 33, 2012.

[14] C. J. De Luca, Surface electromyography: Detection and recording, DelSys Incorporated, vol. 10, no. 2, pp. 110, 2002.

[16] R. Merletti, A. Botter, A. Troiano, E. Merlo, and M. Alessandro, Cli- nical Biomechanics Technology and instrumentation for detection and conditioning of the surface electromyographic signal : State of the art, Clinical Biomechanics, vol. 24, no. 2, pp. 122134, 2009.

[17] L. A. Geddes and L. E. Baker, Chlorided silver electrodes, Medical Research Engineering, vol. 6, no. (3), pp. 3334, 1967.

[18] M. J. Zwarts and D. F. Stegeman, Multichannel surface EMG: Basic aspects and clinical utility, Muscle & Nerve, vol. 28, no. 1, pp. 117, 2003.

[19] R. Merletti, D. Farina, and M. Gazzoni, The linear electrode array: a useful tool with many applications, vol. 13, pp. 3747, 2003.

[20] B. G. Lapatki, J. P. Van Dijk, I. E. Jonas, M. J. Zwarts, and D. F. Stegeman, A thin, exible multielectrode grid for high-density surface EMG, Journal of Applied Physiology, vol. 96, no. 1, pp. 32736, 2004. [21] P. Zhou, M. M. Lowery, K. B. Englehart, H. Huang, G. Li, L. Hargrove,

J. P. A. Dewald, and T. A. Kuiken, Decoding a New Neural Machine Interface for Control of Articial Limbs, pp. 29742982, 2007.

[22] C. J. D. Luca and R. Merletti, Surface myoelectric signal cross-talk among muscles of the leg, pp. 568575, 1988.

[23] J. Rodriguez, F. Daria, and N. Nicolas, Inuence of inter-electrode di- stance, contraction type and muscle on the relationship between the sEMG power spectrum and contraction force, 2014.

[24] G. Klasser and J. P. Okeson, The clinical usefulness of surface elec- tromyography in the diagnosis and treatment of temporomandibular disorders, The Journal of the American Dental Association, vol. 137, no. June, pp. 763771, 2006.

[25] K. Kiguchi, T. Tanaka, and T. Fukuda, Neuro-Fuzzy Control of a Ro- botic Exoskeleton With EMG Signals, vol. 12, no. 4, pp. 481490, 2004.

[26] J. L. A. S. Ramos and M. A. Meggiolaro, Use of Surface Electromyogra- phy for Human Amplication Using an Exoskeleton Driven by Articial Pneumatic Muscles, pp. 585590, 2014.

[27] C. Frigo, M. Ferrarin, W. Frasson, E. Pavan, and R. Thorsen, EMG signals detection and processing for on-line control of functional electri- cal stimulation., Journal of electromyography and kinesiology: ocial journal of the International Society of Electrophysiological Kinesiology, vol. 10, no. 5, pp. 351360, 2000.

[28] R. Merletti, A. Rainoldi, and D. Farina, Surface electromyography for noninvasive characterization of muscle, Exercise and sport sciences reviews, vol. 29, no. 1, pp. 2025, 2001.

[29] ilimb ultra,touch bionics.

[30] J. Ramos and M. Meggiolaro, Use of Surface Electromyography To Con- trol an Active Upper Limb Exoskeleton Actuated By Pneumatic Arti- cial Muscles and Optimized With Genetic, 22nd International Con- gress of Mechanical Engineering (COBEM 2013), vol. 6, no. Cobem, pp. 53765387, 2013.

[31] P. A. Grandjean and J. T. Mortimer, Recruitment properties of monopolar and bipolar epimysial electrodes, no. 82, pp. 5366, 1986. [32]

[33] R. Ru, W. Poppendieck, A. Gail, S. Westendor, M. Russold, S. Lewis, T. Meiners, and K. P. Homann, Acquisition of myoelectric signals to control a hand prosthesis with implantable epimysial electrodes, 2010 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC'10, pp. 50705073, 2010.

[34] J. M. Akers, P. H. Peckham, M. W. Keith, and K. Merritt, Tis- sue Response to Chronically Stimulated Implanted Epimysial and Intramuscular Electrodes, vol. 5, no. 2, pp. 207220, 1997.

[35] K. L. Kilgore, P. H. Peckham, M. Keith, F. W. Montague, R. L. Hart, M. M. Gazdik, A. M. Bryden, S. A. Snyder, and T. G. Stage, Durability of implanted electrodes and leads in an upper-limb neuroprosthesis, Journal of rehabilitation R&D, vol. 40, no. 6, pp. 457468, 2009.

[36] J. P. Uhlir, R. J. Triolo, J. A. Davis, and C. Bieri, Performance of epimysial stimulating electrodes in the lower extremities of individuals with spinal cord injury, IEEE Transactions on Neural Systems and Rehabilitation Engineering, vol. 12, no. 2, pp. 279287, 2004.

[37] M. Ortiz-catalan, B. Håkansson, and R. Brånemark, An osseointegra- ted human-machine gateway for long-term sensory feedback and motor control of articial limbs, vol. 6, no. 257, 2014.

[38] K. L. Kilgore, P. H. Peckham, F. W. Montague, R. L. Hart, A. M. Bryden, M. W. Keith, H. Hoyen, and N. Bhadra, An implanted up- per extremity neuroprosthesis utilizing myoelectric control, 2nd In- ternational IEEE EMBS Conference on Neural Engineering, vol. 2005, no. September, pp. 368371, 2005.

[39] R. L. Waters, J. M. Campbell, and R. Nakai, Therapeutic Electri- cal Stimulation of the Lower Limb by Epimysial Electrodes, Clinical Orthopaedics & Related Research, no. 223, 1988.

[40] P. C.-k. J. L. Smith, Coordination between head and hindlimb motions during the cat scratch response, pp. 279290, 1994.

[41] E. D. Adrian and D. W. Bronk, The discharge of impulses in motor nerve bres: Part II. The frequency of discharge in reex and voluntary contractions., The Journal of physiology, vol. 67, no. 2, pp. i3i151, 1929.

[42] J. Hannerz, An electrode for recording single motor unit activity du- ring strong muscle contractions, Electroencephalography and Clinical Neurophysiology, vol. 37, no. 2, pp. 179181, 1974.

[43] E. Stalberg, Macro EMG, a new recording techinque, Journal of Neurology, Neurosurgery and Psychiatry, vol. 43, pp. 475482, 1980. [44] S. J. Oh, Clinical electromyography: Nerve conduction studies. 2003. [45] J. Kimura, Electrodiagnosis in the disease of nerve and muscle. 2001. [46] Ambu® neuroline monopolar.

[47] R. L. Joynt, The concentric versus the monopolar needle electrode, Muscle and Nerve, vol. 21, no. 12, pp. 18041809, 1998.

[48]

[49] W. Trojaborg, The Case for Concentric Needles, Muscle & Nerve, no. December, pp. 18061809, 1998.

[50] S. D. Nandedkar and D. B. Sanders, Recording characteristics, no. February, pp. 108112, 1991.

[51] A. J. Haig, C. W. Goodmurphy, A. R. Harris, A. P. Ruiz, and J. Etemad, The accuracy of needle placement in lower-limb muscles: A blinded study, Archives of Physical Medicine and Rehabilitation, vol. 84, no. 6, pp. 877882, 2003.

[52] J. A. Strommen and J. R. Daube, Determinants of pain in needle elec- tromyography, Clinical Neurophysiology, vol. 112, no. 8, pp. 14141418, 2001.

[53] D. F. Stegeman, T. H. Gootzen, M. M. Theeuwen, and H. J. Vinge- rhoets, Intramuscular potential changes caused by the presence of the recording EMG needle electrode, Electroencephalography and Clinical Neurophysiology/ Evoked Potentials, vol. 93, no. 2, pp. 8190, 1994. [54] G. R. Naik, Applications, Challenges, and Advancements in Electromyo-

[55] J. Basmajian and G. Stecko, A new bipolar electrode for elec- tromyography, Journal of Applied Physiology, vol. 17, p. 849, 1962.

[56] B. Jonsson and U. E. Bagge, Displacement, deformation and fracture of wire electrodes for electromyography, Electromyography, no. 8, pp. 329 347, 1968.

[57] R. Shiav, A wire multielectrode for intramuscular recording, Medical and Biological Engineering, no. September, pp. 722 723, 1974.

[58] T. J. Steiner, A. J. Thexton, and W. V. Weber, An EMG electrode system for selected-site recording from a muscle, Journal of Applied Physiology, vol. 32, no. 4, pp. 531532, 1972.

[59] A. Rosenfalck, Recording from Single Motor Unit During Strong Eort, no. 6, pp. 501508, 1978.

[60] A. Gydikov, D. Kosarov, A. Kossev, K. Kostov, N. Trayanova, and N. Ra- dicheva, Motor unit potentials at high muscle activity recorded by selec- tive electrodes, Biomedica biochimica acta, vol. 45, no. 1-2, pp. S688, 1986.

[61] C. W. Caldwell and J. B. Reswick, A percutaneous wire electrode for chronic researche use, IEEE Transections on Biomedical Engineering, vol. September, no. 4, pp. 429432, 1975.

[62] W. Memberg, P. Peckham, and M. Keith, A surgically implanted intra- muscular electrode for an implantatble neuromuscular stimulation sy- stem, IEEE Trans. on Rehabilitation Engineering, vol. 2, no. 2, p. 80, 1994.

[63] W. D. Memberg, T. G. Stage, and R. F. Kirsch, A fully im- planted intramuscular bipolar myoelectric signal recording electrode, Neuromodulation, vol. 17, no. 8, pp. 794799, 2014.

[64] I. C. Sando, M. K. Leach, S. L. Woo, J. D. Moon, P. S. Cederna, N. B. Langhals, and M. G. Urbanchek, Regenerative Peripheral Nerve In- terface for Prostheses Control: Electrode Comparison, pp. 194199, 2016.

[65] B. S. Rajaratnam, J. C. H. Goh, and V. P. Kumar, Physical Medicine & Rehabilitation A Comparison of EMG Signals from Surface and Fine- Wire Electrodes During Shoulder Abduction, vol. 2, no. 4, pp. 27, 2014.

[66] I. A. F. Stokes, S. M. Henry, and R. M. Single, Surface EMG electrodes do not accurately record from lumbar multidus muscles, vol. 18, pp. 9 13, 2003.

[67] C. G. Bugar, F. J. Valero-Cuevas, and V. R. Hentz, Fine wire elec- tromyographic recording during force generation, American Journal of Physical Medicine & Rehabilitation, vol. 76, no. 6, pp. 495501, 1997. [68] W. Darling and K. J. Cole, Muscle activation patterns and kinetics of

human index nger movements, Journal of Neurophysiology, vol. 63, no. 5, 1990.

[69] W. D. Memberg, P. H. Peckham, G. B. Thrope, M. W. Keith, and T. P. Kicher, An Analysis of the Reliability of Percutaneous Intramuscular Electrodes in Upper Extremity FNS Applications, vol. 1, no. 2, 1993. [70] A. R. Schwartz, D. W. Eisele, A. Hari, R. O. Y. Testerman, L. Smith,

and R. Alan, Electrical stimulation of the lingual in obstructive sleep apnea musculature, 1996.

[71] K. Yoshida, K. Hennings, and S. Kammer, Acute Performance of the Thin-Film Longitudinal Intra-Fascicular Electrode, 2001.

[72] D. Farina, K. Yoshida, T. Stieglitz, and K. P. Koch, Multichannel thin- lm electrode for intramuscular electromyographic recordings, Journal of Applied Physiology, vol. 104, pp. 821827, jan 2008.

[73] W. Poppendieck, K. P. Homann, E. Rocon, J. L. Pons, S. Muce- li, J. Dideriksen, and D. Farina, Multi-channel EMG recording and muscle stimulation electrodes for diagnosis and treatment of tremor, 2014 IEEE 19th International Functional Electrical Stimulation Society Annual Conference, IFESS 2014 - Conference Proceedings, pp. 1417, 2014.

[74] G. S. Guvanasen, L. Guo, R. J. Aguilar, A. L. Cheek, C. S. Shafor, S. Rajaraman, T. R. Nichols, and S. P. DeWeerth, A Stretchable Mi- croneedle Electrode Array for Stimulating and Measuring Intramuscular Electromyographic Activity, IEEE Transactions on Neural Systems and Rehabilitation Engineering, vol. 4320, no. c, pp. 11, 2016.

[75] R. Weir, P. Troyk, G. Demichele, and D. Kerns, Technical Details of the Implantable Myoelectric Sensor (IMES) System for Multifunction Prosthesis Control., 2005 IEEE Engineering in Medicine and Biology 27th Annual Conference, vol. 7, pp. 73377340, 2005.

[76] I. Arcos, R. Davis, K. Fey, D. Mishler, D. Sanderson, C. Tanacs, M. J. Vogel, R. Wolf, Y. Zilberman, and J. Schulman, Second Generation Microstimulator, vol. 26, no. 3, pp. 228231, 2002.

[77] S. Schlatter, Implantable Myoelectric Sensors for Intramuscular EMG Recording, IEEE Transactions on Biomedical Engineering, vol. 56, no. 1, p. 2009, 2009.

[78] P. F. Pasquina, M. Evangelista, A. J. Carvalho, J. Lockhart, S. Grin, G. Nanos, P. McKay, M. Hansen, D. Ipsen, J. Vandersea, J. Butkus, M. Miller, I. Murphy, and D. Hankin, First-in-man demonstration of a fully implanted myoelectric sensors system to control an advanced electromechanical prosthetic hand, Journal of Neuroscience Methods, vol. 244, pp. 8593, 2015.

[79] J. J. Baker, E. Scheme, K. Englehart, D. T. Hutchinson, and B. Greger, Continuous Detection and Decoding of Dexterous Finger Flexions With Implantable MyoElectric Sensors, vol. 18, no. 4, pp. 424432, 2010.

[80] R. Richardson, J. Miller, and W. Reichert, Polyimides as biomaterials: preliminary biocompatibility testing, Biomaterials, vol. 14, pp. 627635, jan 1993.

[81] N. Lago, D. Ceballos, F. J Rodriguez, T. Stieglitz, and X. Navarro, Long term assessment of axonal regeneration through polyimide regenerati- ve electrodes to interface the peripheral nerve, Biomaterials, vol. 26, pp. 20212031, may 2005.

[82] S. Wurth, M. Capogrosso, S. Raspopovic, J. Gandar, G. Federici, N. Ki- nany, A. Cutrone, A. Piersigilli, N. Pavlova, R. Guiet, G. Taverni, J. Ri- gosa, P. Shkorbatova, X. Navarro, Q. Barraud, G. Courtine, and S. Mi- cera, Long-term usability and bio-integration of polyimide-based intra- neural stimulating electrodes, Biomaterials, vol. 122, pp. 114129, apr 2017.

[83] N. Lago, D. Ceballos, F. J Rodriguez, T. Stieglitz, and X. Navarro, Long term assessment of axonal regeneration through polyimide regenerati- ve electrodes to interface the peripheral nerve, Biomaterials, vol. 26, pp. 20212031, may 2005.

[84] A. Cutrone, J. D. Valle, D. Santos, J. Badia, C. Filippeschi, S. Micera, X. Navarro, and S. Bossi, A three-dimensional self-opening intraneural peripheral interface (SELINE), Journal of Neural Engineering, vol. 12, p. 016016, feb 2015.

[85] A. Branner, R. Stein, E. Fernandez, Y. Aoyagi, and R. Normann, Long-Term Stimulation and Recording With a Penetrating Microelec- trode Array in Cat Sciatic Nerve, IEEE Transactions on Biomedical Engineering, vol. 51, pp. 146157, jan 2004.

[86] A. Cutrone, P. N. Sergi, S. Bossi, and S. Micera, Modelization of a self-opening peripheral neural interface: A feasibility study, Medical Engineering & Physics, vol. 33, pp. 12541261, dec 2011.

[87] A. Cutrone, S. Bossi, and S. Micera, Development of a Self-Opening Neural Interface, Journal of Medical Devices, vol. 7, p. 020938, jun 2013.

[88] P. A. Huijing, A. A. H. van Lookeren Campagne, and J. Koper, Mu- scle Architecture and Fibre Characteristics of Rat Gastrocnemius and Semimembranosus Muscles during Isometric Contractions, Acta Anat, vol. 135, pp. 4652, 1989.

[89] G. J. C. Ettema and P. A. Huijing, Eects of distribution of muscle ber length on active length-force characteristics of rat gastrocnemius medialis, The Anatomical Record, vol. 239, pp. 414420, aug 1994. [90] K. M. Norenberg, Contractile responses of the rat gastrocnemius

and soleus muscles to isotonic resistance exercise, Journal of Applied Physiology, vol. 97, pp. 23222332, dec 2004.

[91] C. J. Zuurbier and P. A. Huijing, Changes in geometry of activily shor- tening unipennate rat gastrocnemius muscle, Journal of Morphology, vol. 218, no. 2, pp. 167180, 1993.

[92] C. M. Eng, L. H. Smallwood, M. P. Rainiero, M. Lahey, S. R. Ward, and R. L. Lieber, Scaling of muscle architecture and ber types in the rat hindlimb, Journal of Experimental Biology, vol. 211, pp. 23362345, jul 2008.

[93] L. C. WANG and D. KERNELL, Fibre type regionalisation in lo- wer hindlimb muscles of rabbit, rat and mouse: a comparative study, Journal of Anatomy, vol. 199, pp. 631643, dec 2001.

[94] J. J. De Koning, H. F. Van Der Molen, R. D. Woittiez, and P. A. Hui- jing, Functional characteristics of rat gastrocnemius and tibialis anterior muscles during growth, Journal of Morphology, vol. 194, pp. 7584, oct 1987.

[95] D. Tasi¢, D. Dimov, J. Gligorijevi¢, V. Ljubinka, K. Katarina, K. Miljan, and I. Dimov, Muscle bre types and bre morphometry in the tibialis

posterior and anterior of the rat: a comparative study, FACTA UNI- VERSITATIS Series: Medicine and Biology, vol. 10, no. 1, pp. 1621, 2003.

[96] U. Slawinska and S. Kasicki, Altered electromyographic activity pat- tern of rat soleus muscle transposed into the bed of antagonist muscle, Journal of Neuroscience, vol. 22, no. 14, pp. 58085812, 2002.

[97] R. B. Armstrong and R. O. Phelps, Muscle ber type composition of the rat hindlimb, Am J Anat, vol. 171, no. 3, pp. 259272, 1984. [98] B. Mierzejewska-Krzy»owska, H. Drzymaªa-Celichowska, D. Bukowska,

and J. Celichowski, Gender Dierences in Morphometric Properties of Muscle Fibres Measured on Cross-Sections of rat Hindlimb Muscles, Anatomia, Histologia, Embryologia, vol. 41, pp. 122129, apr 2012. [99] K. Kanda and K. Hashizume, Changes in properties of the medial

gastrocnemius motor units in aging rats, J Neurophysiol., vol. 61, no. 0022-3077, pp. 737746, 1989.

[100] W. Jensen, K. Yoshida, and U. G. Hofmann, Peripheral Nervous Tissue, Biomedical Engineering, pp. 20072010, 2007.

[101] G. Liu, Q. Zhang, Y. Jin, and G. Z, Stress and strain analysis on the anastomosis site sutured with either epineurial or perineurial sutures after simulation of sciatic nerve injury, Neural Regeneration Research, vol. 7, no. 29, pp. 22992304, 2012.

[102] Y. Gao and T. Kostrominova, Age-related changes in the mechani- cal properties of the epimysium in skeletal muscles of rats, Journal of Biomechanics, vol. 41, no. 2, pp. 465469, 2008.

[103] M. S. Ju, C. C. K. Lin, J. L. Fan, and R. J. Chen, Transverse elasticity and blood perfusion of sciatic nerves under in situ circular compression, Journal of Biomechanics, vol. 39, no. 1, pp. 97102, 2006.

[104] I. V. Ogneva, D. V. Lebedev, and B. S. Shenkman, Transversal stiness and young's modulus of single bers from rat soleus muscle probed by atomic force microscopy, Biophysical Journal, vol. 98, no. 3, pp. 418 424, 2010.