The objective of this study was to compare the effects of postoperative pain following ovariohysterectomy via harmonic scalpel assisted laparoscopy (HALO) and traditional ovariohysterectomy (OVH) in dogs. The study was designed as a randomized, blinded, prospective study. Sixteen, purpose-bred, intact female, Beagle dogs were used to complete the study. Dogs were placed into two groups. Group 1 included (8 dogs) that underwent ovariohysterectomy via HALO. Group 2 included (8 dogs) that underwent ovariohysterectomy via traditional OVH. Physiologic data, abdominal nociceptive threshold scores, and University of Melbourne pain scores (UMPS) were recorded at 2, 6, 12, 24, 48, and 72 hours following surgery. Blood samples for plasma cortisol, glucose, and creatine phosphokinase (CPK) were taken at the time of the incision and 2, 6, 12, 24, 48, and 72 hours following surgery. No significant surgical complications were encountered in either group. The HALO mean surgical time was significantly longer (55.7 minutes) than the traditional OVH (31.7 minutes). No significant differences were observed between the two groups for the pain measures of heart rate, respiratory rate, temperature, CPK, and glucose. The OVH group had significantly higher mean plasma cortisol levels at hour 2 following surgery than the HALO group (P=0.0001). The mean UMPS were significantly higher in the OVH group than the HALO group at all postoperative times (P=0.0001). Mean nociceptive threshold measurements revealed significantly higher tolerated palpation pressures in the HALO than the OVH group at all postoperative times, except hour 72 (P=0.0002). Dogs in this study appeared to be less painful with HALO procedures versus traditional OVH. The harmonic scalpel coagulated ovarian and uterine vessels completely with minimal collateral damage to surrounding tissues. The clinical relevance of this study demonstrates that harmonic scalpel-assisted laparoscopic ovariohysterectomy is a safe alternative to traditional OVH and offers a minimally invasive and less painful method of surgery. / Master of Science

Magister Chirurgiae Dentium - MChD / This study compares the CMN to the steel scalpel by assessing incision time, incisional blood loss, postoperative pain, wound healing, and the incidence of lingual and long buccal nerve injury. Twenty standardised cases were included in an analytical prospective case series. Each case had one side cut with CMN and the other side with steel scalpel. Third molar surgery is the most commonly performed procedure by maxillo-facial and oral surgeons, and is associated with expected but transient sequelae such as pain, swelling and trismus. Modalities to reduce the severity of these sequelae are desirable. Several studies report that the use of conventional electrosurgical instruments and the Colorado Microdissection Needle (CMN) resulted in significant reductions in cutting time, incisional blood loss, postoperative pain, with no evidence of increased incidence of wound complications such as dehiscence and infection.

Objective - To evaluate a surgical technique for performing laparoscopic bilateral ovariectomy in standing horses. Study Design - Experimental study. Animals or Sample population - 8 mares, age 2-20 years, weight 410-540 kg. Methods - Standing laparoscopic bilateral ovariectomy was performed in 8 mares with normal anatomy of the reproductive tract. The Harmonic Scalpel (an ultrasonically activated instrument) was used to transect the ovarian pedicle and to obtain hemostasis simultaneously. Necropsy was performed on 4 mares 3 days after surgery and 30 days following surgery on the remaining 4 mares. Gross and histopathologic evaluation of the ovarian pedicles was performed to characterize the effects of the Harmonic Scalpel on the transected tissue. Results - The Harmonic Scalpel achieved complete hemostasis of the vasculature of the ovarian pedicles in all mares. Median transection time for the ovarian pedicle was 28 minutes. Postoperative complications included transient fever in one mare, moderate subcutaneous emphysema in another, and incisional seroma formation in a third mare. Post-mortem examination 3 and 30 days postoperatively revealed no signs of generalized peritonitis, postoperative hemorrhage or adhesion formation. Mild to moderate acute inflammation, and scar formation with moderate chronic inflammation at the ovarian pedicle was found 3 and 30 days after surgery, respectively. Median depth of coagulation necrosis 3 days postoperatively was 2.87 mm. Conclusions - The Harmonic Scalpel appears to provide reliable hemostasis of the ovarian pedicle during elective laparoscopic ovariectomy in horses. Clinical Relevance - The Harmonic Scalpel represents a safe alternative to other means of hemostasis during elective laparoscopic ovariectomy in horses. / Master of Science

Este trabalho teve por objetivo desenvolver e caracterizar um conjunto transdutor piezelétrico de potência e pinça laparoscópica para cortes homeostáticos, o qual constitui parte fundamental do projeto do Bisturi Ultrassônico Nacional. O transdutor, do tipo Langevin, é composto por quatro cerâmicas piezelétricas que convertem energia elétrica em deslocamento mecânico. Um componente importante do transdutor é o amplificador mecânico, cuja finalidade é aumentar a amplitude do deslocamento. O transdutor e o amplificador foram desenvolvidos através de um modelo axissimétrico de elementos finitos implementado no software ANSYS e a lâmina foi desenvolvida através de um modelo tridimensional em elementos finitos. Para cada associação, entre os componentes, os resultados numéricos da resposta em frequência da impedância elétrica e do coeficiente de acoplamento eletromecânico, foram comparados com os resultados experimentais. Também foi desenvolvido um mecanismo inovador de acionamento da pinça laparoscópica. O resultado desta pesquisa proporcionou uma inovação tecnológica na área médica, contribuindo assim para o progresso tecnológico do país. / The aim of this work was to develop and characterize a high power piezoelectric transducer coupled to a laparoscopic forceps for homeostatic cuts, which is a fundamental part of the National Ultrasonic Scalpel Project. The Langevin type transducer consists of four piezoelectric ceramics that convert electrical energy into mechanical displacement. An important component of the transducer is the mechanical amplifier, which increases the amplitude of displacement. The transducer and amplifier have been developed through an axisymmetric finite element model, implemented in ANSYS, and the blade was developed using a three-dimensional finite element model. For each association between the components, the numerical results of the frequency response of the electrical impedance and electromechanical coupling coefficient were compared with the experimental results. An innovative drive mechanism was developed for the laparoscopic forceps. The result of this research provided a technological innovation in the medical field, thus contributing to the technological progress of the country.

Orientador: Carlos Alberto Canesin / Resumo: Neste trabalho, apresentou-se o estudo de um gerador eletrocirúrgico utilizando um conversor ressonante. Com o intuito de realizar procedimentos cirúrgicos, o bisturi elétrico, ou eletrônico, apresenta grandes vantagens ao método clássico do bisturi de aço inoxidável. Para conseguir os efeitos terapêuticos desejados, corte e coagulação, sem que haja qualquer estímulo nervoso, utiliza-se sinal senoidal com alta frequência. Os conversores ressonantes são estruturas chaveadas que operam em elevadas frequências com baixas perdas, logo, alto rendimento. Fez-se, então, um estudo sobre as estruturas inversoras e os filtros ressonantes. A sequência do trabalho trata da análise da estrutura proposta (Full-Bridge – LCLC – ZVS – FM) demonstrando as etapas envolvidas em um ciclo de chaveamento do conversor e o seu equacionamento. A partir de uma metodologia para calcular os parâmetros do filtro, definiram-se os valores das indutâncias e das capacitâncias séries e paralelas. Projetou-se o controlador pormeio de umametodologia que visa o controle pelos valores de pico das formas de onda. Realizaram-se simulações dos modos de operação desejados e observaram-se os valores encontrados da tensão de saída, da corrente de saída, da corrente de entrada e a comutação ZVS para variadas cargas. Implementou-se um protótipo do qual os resultados práticos obtidos são apresentados e discutidos. / Abstract: In this work, a study of an electrosurgical generator was presented using a resonant converter. In order to perform surgical procedures, electric or electronic scalpel presents great advantages to the classic method of the stainless steel scalpel. To achieve the desired therapeutic effects, cutting and coagulation, without any nerve stimulation, sine wave signal is applied with high frequency. Resonant converters are switched structures that operate at high frequencies with low losses, hence, high efficiency. A study was then made about inverter structures and resonant filters. The work sequence was the analysis of the proposed structure (Full-Bridge LCLCZVS- FM) demonstrating the steps involved in a converter switching cycle and its equation. From a methodology to calculate filter parameters, values of series and parallel inductances and capacitances were defined. The controller was designed using a methodology that controls the peak values of the waveforms. Simulations of the desired modes of operation were executed out and the values of output voltage, output current, input current and ZVS switching were observed for various loads. A prototype was implemented and the results obtained are presented and discussed. / Mestre

Este trabalho teve por objetivo desenvolver e caracterizar um conjunto transdutor piezelétrico de potência e pinça laparoscópica para cortes homeostáticos, o qual constitui parte fundamental do projeto do Bisturi Ultrassônico Nacional. O transdutor, do tipo Langevin, é composto por quatro cerâmicas piezelétricas que convertem energia elétrica em deslocamento mecânico. Um componente importante do transdutor é o amplificador mecânico, cuja finalidade é aumentar a amplitude do deslocamento. O transdutor e o amplificador foram desenvolvidos através de um modelo axissimétrico de elementos finitos implementado no software ANSYS e a lâmina foi desenvolvida através de um modelo tridimensional em elementos finitos. Para cada associação, entre os componentes, os resultados numéricos da resposta em frequência da impedância elétrica e do coeficiente de acoplamento eletromecânico, foram comparados com os resultados experimentais. Também foi desenvolvido um mecanismo inovador de acionamento da pinça laparoscópica. O resultado desta pesquisa proporcionou uma inovação tecnológica na área médica, contribuindo assim para o progresso tecnológico do país. / The aim of this work was to develop and characterize a high power piezoelectric transducer coupled to a laparoscopic forceps for homeostatic cuts, which is a fundamental part of the National Ultrasonic Scalpel Project. The Langevin type transducer consists of four piezoelectric ceramics that convert electrical energy into mechanical displacement. An important component of the transducer is the mechanical amplifier, which increases the amplitude of displacement. The transducer and amplifier have been developed through an axisymmetric finite element model, implemented in ANSYS, and the blade was developed using a three-dimensional finite element model. For each association between the components, the numerical results of the frequency response of the electrical impedance and electromechanical coupling coefficient were compared with the experimental results. An innovative drive mechanism was developed for the laparoscopic forceps. The result of this research provided a technological innovation in the medical field, thus contributing to the technological progress of the country.

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Disertační práce se zabývá detailním studiem vlastností různých elektrických výbojů generovaných ve vodných roztocích. Tyto výboje se staly v posledním desetiletí velmi populárním tématem, a to zejména díky mnoha praktickým využitím jako například v biomedicíně, čištění odpadních vod, ekologii nebo nanoinženýrství. Studium je zaměřeno na generaci peroxidu vodíku, jakožto jednu z nejvýznamnějších částic generovaných právě elektrickými výboji v kapalinách. Pro první část této práce byla využita speciální výbojová komora zkonstruovaná na Fakultě chemické Vysokého Učení Technického v Brně. Komora byla rozdělena tenkou diafragmovou přepážkou na dvě poloviny, přičemž uvnitř přepážky se nacházela malá dírka. V každé části komory se nacházela jedna elektroda, a obě dvě části komory byly vyplněny kapalinou. Ze zdroje bylo do kapaliny aplikováno vysokofrekvenční napětí (1 a 2 kHz), které tak vlastně upravovalo roztok chloridu sodného (1.5 l). Bylo zjištěno, že tento druh napětí, v porovnání s DC, nezpůsobuje nežádoucí přehřívání roztoku (počáteční vodivost 100 - 800 S/cm) během jeho úpravy při zachování účinnosti produkce peroxidu. Experimentální aparatura pro druhou část práce byla sestavena na Gentské Univerzitě v Belgii. Stejnosměrný výboj byl generován v bublinách plynů (He, Ar, N2, vzduch) v prostředí vodných roztoků. Byla studována generace peroxidu vodíku a odbourávání organických barviv přítomných ve zkoumaném roztoku. Ke generaci peroxidu vodíku byl použit roztok NaH2PO4 . 2H2O (5 microS/cm, V= 750 ml), ke zkoumání rozkladu barviv byly použity roztoky organických barviv Direct Red 79 (20 mg/l) a Direct Blue 106 (20 mg/l, V= 750 ml). Minimální koncentrace peroxidu vodíku byla naměřena při aplikaci proudu 10 mA, zatímco maximální koncentrace peroxidu vodíku byla zaznamenána při použití proudu 30 mA. Rozklad organických barviv vykazoval stejné vlastnosti. Čím vyšší byla dodávaná energie, tím více barviva se odbouralo. Třetí část práce probíhala ve spolupráci s Queen's University of Belfast, Centrum for Plasma Physics, UK. K realizaci experimentů bylo využito vysokofrekvenčního plazmového skalpelu (Arthrocar). Bylo zjištěno, že hodnota koncentrace peroxidu vodíku dosahovala maxima v roztocích s nepatrným přídavkem alkoholu (0.25 %). Celkem byly studovány čtyři 0.15 M roztoky BaCl2, Na2CO3, KCl a NaCl (V= 20 ml), jejichž počáteční vodivost se pohybovala kolem 13 mS/cm. Z výsledků bylo patrné, že největší rozdíl hodnot pH byl zaznamenán u roztoků s přídavkem ethanolu. V optických emisních spektrech byly identifikovány především radikály OH, které jsou prekurzory peroxidu vodíku. Výsledky ukázaly, že plazma v takovémto roztoku je stále tvořeno, což může být považováno za první krok generace plazmatu v organických sloučeninách. Poslední část práce byla zaměřena na tzv. mikroplazmatický jet v přímém kontaktu s kapalnou fází. Tato experimentální práce byla realizována na pracovišti Nanotechnology & Integrated Bio-Engineering Centre (NIBEC), University of Ulster, UK během studijní stáže. Jako vodivé médium byl použit roztok trihydrátu kyseliny chlorozlatité s různou počáteční vodivostí. Zajímavým zjištěním je fakt, že při tomto druhu měření bylo generováno stabilní plazma i při velmi malém výbojovém proudu (0.05 a 0.2 mA), a tedy i peroxid vodíku vznikal při velmi malé vstupní energii, což může být považováno za velmi dobrý výsledek.