mgr inż. Tomasz Moszkowski

Supervisor: prof. dr hab. inż. Piotr Augustyniak (AGH) Assisting supervisor: Prof. Dr. Ing- Klaus-Peter Hoffmann (Fraunhofer IBMT) Discipline: Biocybernetics and Biomedical Engineering

INTRODUCTION: Surgery is the main treatment option for rectal cancer patients and poses the risk of postoperative anorectal and urogenital dysfunction due to iatrogenic nerve damage. Pelvic intraoperative neuromonitoring (pIONM) offers the surgeon a means to preserve the autonomic nervous system by monitoring the anorectal and urogenital function during total mesorectal excision (TME).

OBJECTIVES: The described dissertation aimed to prove the following thesis statement:

Investigating the electrical and spatial parameters of electrical stimulation of the autonomous nervous system within the pelvic floor by a combination of numerical and in-vivo modeling is an effective tool to assess the feasibility of transcutaneous electrical nerve stimulation for the purposes of pelvic intraoperative neurophysiological monitoring.

The suitability for intraoperative nerve mapping and function monitoring formed the main criteria for assessing the feasibility of TENS for pIONM.

METHODS: Finite element modeling (FEM) of the electrical field resulting from DNS and TENS, the influence of the modeled electrical field on the activation of a model of the autonomic nervous system, and experimental investigation on five male porcine specimens were investigated to evaluate the suitability of TENS for intraoperative nerve mapping and function monitoring.

RESULTS: The simulated electric field distribution within the lesser pelvis due to DNS and TENS caused activation of the autonomic nervous system for specific stimulation sites and electrode configurations. DNS exhibited higher selectivity in evoking action potentials in specific nerve fibers. Narrow stimulation amplitude ranges and a small number of effective electrode configurations limited the stimulation selectivity and sensitivity to nerve damage during TENS. Although suitable for the identification of nerve damage via DNS, the standard processed EMG of the internal anal sphincter (IAS) could not be used during TENS because of the presence of stimulation artifacts. Previously unobserved evoked potentials within the IAS activity due to DNS and TENS were discovered and their presence was associated with damage of the inferior hypogastric plexus. Possible influence of muscular relaxants on the recorded signals was identified.

CONCLUSION: The combination of numerical and in-vivo modeling proved an effective tool in assessing the suitability of TENS for pIONM. TENS proved to be impractical for intraoperative nerve mapping because of limited stimulation selectivity. The electrode configurations associated with identifying the nerve damage suggested the suitability of TENS for function monitoring. However, the specific stimulation conditions needed for achieving sensitivity to nerve damage resulted in a limited number of cases that had to be additionally validated by targeted nerve incision.

OUTLOOK: Future research should focus on improving the sensitivity of monitoring the nerve damage by improving the stimulation and signal acquisition methods.

SIGNIFICANCE: Extracorporeal stimulation of the pelvic autonomic nerves might reduce the time needed for preoperative preparation, allow continuous monitoring of the neural function, and lead to better functional preservation following TME.

Autoreferat w języku polskim znajduje się tutaj.

Pełna treść rozprawy doktorskiej znajduje się tutaj.

1. Moszkowski T., Kauff D,. Wegner C., Ruff R., Somerlik-Fuchs K., Krueger T., Augustyniak P., Hoffmann K-P., Kneist W. Extracorporeal stimulation of sacral nerve roots for observation of pelvic autonomic nerve integrity: Description of a novel methodological setup, IEEE Transactions on Biomedical Engineering, 2017
2. Kauff D., Moszkowski T., Wegner C., Heimann A., Hoffmann K-P., Krueger T., Lang H., Kneist W. Transcutaneous sacral nerve stimulation for intraoperative verification of internal anal sphincter innervation, Neurogastroenterology & Motility, 2017
3. Kauff D., Moszkowski T., Ruff R., Kneist W., Multifunctional surface probe for less invasive stimulation of sacral somatic and autonomic outflow under EMG feedback control, Current Directions in Biomedical Engineering, 2017
4. Kauff D., Moszkowski T., Wachter N., Heimann A., Kneist W., Minimally invasive transanal pelvic autonomic nerve stimulation for intraoperative verification of functional nerve integrity, 134th Congress of the German Society of Surgery (DGCH), 2017
5. Moszkowski T., Krueger T., Kneist W., Hoffmann K-P. Modeling in the pelvic region for non-invasive pelvic intraoperative neuromonitoring, Current Directions in Biomedical Engineering, 2016
6. Wróbel T., Marzec K., Chłopicki S., Maślak E., Jasztal A., Franczyk-Żarów M., Czyżyńska-Cichoń I., Moszkowski T., Kostogrys R., Barańska M., Effects of low carbohydrate high protein (LCHP) diet on atherosclerotic plaque phenotype in ApoE/LDLR mice: FT-IR and Raman imaging, Scientific Reports, 2015
7. Lang T., Cardona Audi J., Moszkowski T., Ruff R., Hoffmann K-P., DSP-based real-time compression of bio-signals for intelligent implants, Biomedizinische Technik, 2014

1. Pracownik naukowy w projekcie autoPIN przy współpracy z inomed Medizintechnik GmbH w Emmendingen, Fraunhofer Institut für Biomedizinische Technik w St. Ingbert oraz Uniwersytetem Medycznym im. J. Gutenberga w Moguncji, dofinansowanym przez Ministerstwo Oświaty i Nauki Republiki Federalnej Niemiec (BMBF)
2. Kierownik projektu pt. Ocena zdatności jednokanałowej elektrody powierzchniowej do odczytu zapisu elektromiograficznego kompleksu zwieraczy odbytnicy w neuromonitoringu śródoperacyjnym w chirurgii miednicy mniejszej przy współpracy z Uniwersytetem Jagiellońskim w Krakowie oraz inomed Polska Sp. z o.o., dofinansowanego z Funduszy Europejskich w ramach Programu Operacyjnego 1.2.3. Bony na innowacje

• prof. dr hab. inż. Jerzy Wtorek, Politechnika Gdańska Recenzja nr 1
• prof. dr hab. inż. Ewa Zalewska, PAN Recenzja nr 2