METHODOLOGY FOR RESEARCH AND DEVELOPMENT OF NOVEL MEDICAL DEVICES FOR MINIMALLY INVASIVE INTERVENTIONS

The design of innovative medical device requires extensive and hard efforts to reach good results in terms of safety, efficacy and cost effectiveness. First of all the idea has to be set and a wide search of state of the art, both technological and academic, has to be developed. Then the materials, manufacturing processes and design constraints have to be understood. In this work three examples of innovative surgical devices for minimally invasive surgery and assistance have been presented. The Muneretto Beam catheter is a new device for atrial defibrillation. Starting from a catheter produced by Estech company for the treatment of atrial fibrillation by ablating cardiac tissue during surgery, a system for the magnetic guidance of the same has been implemented. Thanks to finite element analysis of various configurations of magnets and to several in vitro tests, a final configuration which allows a good balance between the sliding of the catheter on the tissues and the magnetic interaction and adhesion to tissues has been found. Further attention has been taken to the development of the cover and the right configuration and method of use of the device. The VideoDrain system is a new catheter for the monitoring of post-operative wound. After critical surgical procedures it is necessary to monitor the status of the surgical wound for avoiding second look surgical interventions. Therefore a new balloon catheter for allowing the vision of the abdominal cavity has been produced. Several in vitro and in vivo trials have been conducted and the device is at the pre-industrial stage. The FloSeal GI cath. is a new device for the gastrointestinal release of an haemostatic substance of the Baxter company: the Floseal thrombin matrix. It consists in a balloon catheter suited for the use in the lower and upper gastrointestinal tract in the occurrence of bleedings during endoscopic procedures. This device has been CE labelled and is now on the market. All the devices described in this work come from ideas of surgeons leader in innovation in the field of minimally invasive interventions. Their collaboration has been fundamental for the several phases of design and tests of the devices. This Ph.D. thesis is divided into five chapters. In the Introduction chapter the process of research and development of innovative MDs for minimally invasive surgery has been illustrated. The second chapter shows the efforts done to find a working configuration for the Muneretto Beam catheter and the subsequent first prototypes developed. The progress in the design of VideoDrain has been explained in the third chapter; the whole process goes from the idea to the animal test on prototypes and a preliminary risk analysis. The development of the Floseal GI Catheter is depicted in the fourth chapter; all the details of the materials used and tests done to ensure a CE mark have been reported. Finally, in the Conclusion chapter I have reported some lessons learned from the work in the field of MDs, as a student, researcher and engineer at close contact with the world of surgery and minimally invasive technologies. Some papers about a preliminary research activity in the field of minimally invasive surgery and robotic interventions have been also enclosed. These works have been very useful to start the understanding of the complex and amazing world of MIS

Design and Testing Novel Wearable Instrumentation for Assessing Pelvic Floor Function and Exploring Continence Mechanisms

Urinary incontinence (UI) and fecal incontinence (FI) affect 20% of North Americans, with a higher prevalence in women and the elderly. The prevention and treatment of these conditions unfortunately leaves much to be desired, despite the $88B and$49B annual U.S. costs associated with managing UI and FI, respectively. Recent research suggests that the major problem lies with the sphincters themselves, rather than other structures. More needs to be learned about how age, injury and disease affect these sphincters. The literature is reviewed in Chapter 1, knowledge gaps are identified and testable hypotheses formulated. In Chapter 2, we describe the first subject-specific, 3-D, biomechanics model of the urethra capable of contracting the three individual muscle layers along their lines of action. This was developed to better understand how the different layers contribute to urethral closure during activities of daily living. Exploratory studies of the vascular plexus suggest a role in affecting functional urethral length. While this model helps one to understand which muscles contribute to continence, it could not provide insights into the amount of urine leaked which, after all, is what bothers women the most. In Chapter 3, we describe a novel approach for quantifying urine leakage both in and out of the clinic. While one can presently obtain micturition flowmetry in the seated posture in the clinic, this precludes the possibility of any information being gathered on leakage during activities of daily living (ADL). Instead, a patient must keep a leakage diary for several days, which unfortunately is prone to recall bias and other errors. Therefore, a novel wearable personal uroflowmeter (PUF) was invented and developed to attach over the urethral meatus in women to collect urine flow rate and leakage data during ADL leakage episodes. This was connected with a waist-mounted inertial measurement unit (IMU) to provide data on the pose and ADL associated with the volume of each leakage episode. Chapter 4 describes the first-in-human testing of the PUF in women in and outside the clinic, demonstrating the feasibility of wearable uroflowmetry. Moreover, theoretical studies of labia majora coaptation suggest that the labia can inadvertently form a potential reservoir for urine leakage during a sneeze or cough. This insight will help eliminate the confusion over the relationship between the ADL causing the passage of urine through the urethra (i.e., a cough) and that which later causes urine to leak from the labial reservoir (i.e., rising from a chair). A few incidents of this phenomenon were measured for the first time while testing the PUF in women. In terms of anorectal function, Chapter 5 reports the design and development of a disposable point-of-service instrumented anorectal manometry glove (“digital manometry”, DM) for testing anal sphincter and anorectal function at an order of magnitude lower cost than the standard high resolution anorectal manometry (HR-ARM). Chapter 6 reports first-in-human testing of the DM device in patients with and without FI and chronic constipation. Comparisons of the DM and HR-ARM results show reasonable agreement. In addition, the DM also provided myoelectric information useful for identifying paradoxical contraction of the anorectal muscle in patients with dyssynergic defecation. In summary, the dissertation provides novel and inexpensive approaches for a clinician or researcher to better document and understand incontinence.PHDMechanical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/163121/1/attari_1.pd

Development of a magnetic intra-uterine manipulator

Thesis (MScEng)--Stellenbosch University, 2012.ENGLISH ABSTRACT: Uterine manipulation is integral to obtaining adequate access to the uterus during a laparoscopic procedure. A variety of mechanical manipulators have been developed to aid the surgeon with the dissection of the uterus during laparoscopic hysterectomies. Limitations of existing manipulators are that they require an additional assistant during surgery, are expensive and may cause tissue trauma to the vaginal or cervical canal. This study introduces the novel concept of a magnetic uterine manipulator, intended to overcome existing devices’ shortcomings and enabling non-invasive uterine manipulation. The first goal of the study was to investigate the strengths and weaknesses of existing mechanical manipulators and compare them to those of a magnetic device. Analysis showed that a magnetic manipulator would not be able to compete in terms of the range of motion of existing devices. A limited anteriorsagittal rotation range of 60 was seen in the magnetic manipulator compared to a range of 140 in mechanical devices. However, the magnetic manipulator could eliminate the need for an extra assistant, is reusable and thus also more economical. The second goal was to investigate which type of setup would be most successful at effective uterine manipulation. Through concept analysis a cart-on-arch system was deemed most effective. To lift an effective load of 1 N over an air-gap of 150 mm rare-earth N38 Neodymium (NdFeBr) magnets showed the most promise as magnetic actuators. FEA (Finite Element Analysis) simulations of the magnetic setup were validated experimentally which produced an acceptable MAE (mean absolute error) of 0.15 N. Furthermore, a comparative simulation study of shielded and unshielded magnets was done which concluded that shielded magnets produce a slightly higher attraction force and would be safer to use due to less magnetic flux fringing. Thirdly and lastly, potential safety hazards and risks of using magnetic actuators in surgical environments were identified. The literature research revealed that connections between magnetic fields and health risks to patients have not been conclusively proven in clinical studies to date, but nonetheless, great care should be taken in situations where the patient has a pace-maker or orthopaedic implants, as these might interact with the magnetic field. Recommendations for future work include further research into the geometry and scaling effects of magnetic shielding as well as electromagnetic actuator design. Electromagnetic actuators could replace rare-earth magnets, if coil and cooling systems are optimized, resulting in magnets that can be reversed or switched off and which are therefore easier to control and safer to handle.AFRIKAANSE OPSOMMING: Ontwikkeling van ’n Magnetiese Intra-Uteriene Manipuleerder Baarmoedermanipulasie is van uiterste belang om sodoende voldoende toegang te kry tot die baarmoeder gedurende ’n laparoskopiese prosedure. Daar is reeds ’n verskeidenheid meganiese manipuleerders ontwikkel as hulpmiddel vir die chirurg in die ontleding van die uterus tydens laparoskopiese histerektomies. Beperkings van bestaande manipuleerders is dat ’n bykomende assistent tydens chirurgie benodig word. Die manipuleerders is ook duur en kan weefseltrauma veroorsaak aan die vaginale of servikale kanale. Die studie stel ’n nuwe konsep bekend: ’n magnetiese baarmoedermanipuleerder, gemik daarop om bestaande toestelle se tekortkominge te oorkom en nie-indringende baarmoedermanipulasie moontlik te maak. Die eerste doel van die studie was om die voordele en nadele van bestaande meganiese manipuleerders te ondersoek en dit te vergelyk met dié van die magnetiese toestel. Analise het getoon dat ’n magnetiese manipuleerder nie met bestaande toestelle sal kan kompeteer waar dit gaan om beweegruimte nie. Daar is ’n beperkte anterior-sagitale rotasiespeling van 60 in die magnetiese manipuleerder, terwyl die meganiese toestel ’n rotasiespeling van 140 het. Die magnetiese manipuleerder kan egter die nodigheid van ’n bykomende assistant uitskakel, is herbruikbaar en dus ook meer ekonomies. Die tweede doel van die studie was om die tipe opstelling wat meer suksesvol sal wees tydens doeltreffende baarmoeder manipulasie te ondersoek. Konsep-analise het getoon dat ’n "cart-on-arch"stelsel die beste sal werk. N38 Neodimium (NdFeBr) magnete het die beste vertoon as magnetiese aandrywer om ’n werklike belasting van 1 N oor ’n lugspasie van 150 mm te lig. EEA (Eindige Element Analise) simulasies van die magnetiese opstelling is eksperimenteel bekragtig en het ’n aanvaarbare gemene absolute fout (GAF) van 0.15 N gelewer. ’n Vergelykende simulasie studie het verder gewys dat beskutte magnete ’n effens hoër aantrekkingskrag oplewer en sal dus veiliger wees om te gebruik vanweë die verminderde magnetiese stromingsrand. Derdens en laastens is potensiële veiligheidsrisikos en gevare in die gebruik van magnetiese drywers in chirurgiese omgewings geïdentifiseer. Literatuurnavorsing het onthul dat die verband tussen magneetvelde en gesondheidsrisikos aan pasiënte nog nie voldoende bewys is in kliniese studies tot op datum nie. Gevalle waar pasiënte ’n pasaangeër of ortopediese inplantings het moet met groot sorg hanteer word aangesien dit dalk kan reageer met die magneetvelde. Aanbevelings vir toekomstige werk sluit verdere navorsing in in die rigting van die geometrie en die afskilferingseffek van magnetiese beskutting en ook elektromagnetiese drywer ontwerp. Elektromagnetiese drywers kan moontlik rou aarde magnete vervang indien winding en afkoelstelsels ge-optimeer word wat kan lei tot magnete wat omgekeer of afgeskakel kan word en dus makliker beheerbaar is en veiliger om te hanteer

Advances in Minimally Invasive Surgery

The minimally invasive approach in medicine is one of the most common areas of interest in surgery.Advances in Minimally Invasive Surgery describes the latest trends, indications, techniques, and approaches in minimally invasive surgery. It provides step-by-step instructions for both routine and diagnostic procedures via illustrations and video collection

Colorectal Cancer

Colorectal cancer is one of the commonest cancers affecting individuals across the world. An improvement in survival has been attributed to multidisciplinary management, better diagnostics, improved surgical options for the primary and metastatic disease and advances in adjuvant therapy. In this book, international experts share their experience and knowledge on these different aspects in the management of colorectal cancer. An in depth analysis of screening for colorectal cancer, detailed evaluation of diagnostic modalities in staging colorectal cancer, recent advances in adjuvant therapy and principles and trends in the surgical management of colorectal cancer is provided. This will certainly prove to be an interesting and informative read for any clinician involved in the management of patients with colorectal cancer

Recent Advances in Minimally Invasive Surgery

Minimally invasive surgery has become a common term in visceral as well as gynecologic surgery. It has almost evolved into its own surgical speciality over the past 20 years. Today, being firmly established in every subspeciality of visceral surgery, it is now no longer a distinct skillset, but a fixed part of the armamentarium of surgical options available. In every indication, the advantages of a minimally invasive approach include reduced intraoperative blood loss, less postoperative pain, and shorter rehabilitation times, as well as a marked reduction of overall and surgical postoperative morbidity. In the advent of modern oncologic treatment algorithms, these effects not only lower the immediate impact that an operation has on the patient, but also become important key steps in reducing the side-effects of surgery. Thus, they enable surgery to become a module in modern multi-disciplinary cancer treatment, which blends into multimodular treatment options at different times and prolongs and widens the possibilities available to cancer patients. In this quickly changing environment, the requirement to learn and refine not only open surgical but also different minimally invasive techniques on high levels deeply impact modern surgical training pathways. The use of modern elearning tools and new and praxis-based surgical training possibilities have been readily integrated into modern surgical education,which persists throughout the whole surgical career of modern gynecologic and visceral surgery specialists

Book of Abstracts 15th International Symposium on Computer Methods in Biomechanics and Biomedical Engineering and 3rd Conference on Imaging and Visualization

In this edition, the two events will run together as a single conference, highlighting the strong connection with the Taylor & Francis journals: Computer Methods in Biomechanics and Biomedical Engineering (John Middleton and Christopher Jacobs, Eds.) and Computer Methods in Biomechanics and Biomedical Engineering: Imaging and Visualization (JoãoManuel R.S. Tavares, Ed.). The conference has become a major international meeting on computational biomechanics, imaging andvisualization. In this edition, the main program includes 212 presentations. In addition, sixteen renowned researchers will give plenary keynotes, addressing current challenges in computational biomechanics and biomedical imaging. In Lisbon, for the first time, a session dedicated to award the winner of the Best Paper in CMBBE Journal will take place. We believe that CMBBE2018 will have a strong impact on the development of computational biomechanics and biomedical imaging and visualization, identifying emerging areas of research and promoting the collaboration and networking between participants. This impact is evidenced through the well-known research groups, commercial companies and scientific organizations, who continue to support and sponsor the CMBBE meeting series. In fact, the conference is enriched with five workshops on specific scientific topics and commercial software.info:eu-repo/semantics/draf