Meningiomas petroclivais são tumores da base do crânio desafiadores para ressecção cirúrgica devido a sua localização profunda e relação com estruturas neurovasculares vitais. Geralmente são lesões benignas, mas podem envolver ou infiltrar o osso da base do crânio, dura-máter, tronco encefálico e todas as estruturas neurovasculares desta região, tornando a remoção total difícil sem causar déficits neurológicos. O objetivo deste estudo é revisar uma série de casos de meningiomas petroclivais tratados cirurgicamente em centro de referência de base de crânio, considerando os fatores determinantes para a escolha da abordagem. A casuística foi analisada com coleta retrospectiva dos dados. Devido à dificuldade de acesso, essas lesões geralmente requerem diferentes abordagens cirúrgicas e apresentam dificuldades cirúrgicas distintas. Embora as abordagens fronto-órbito-zigomática, petrosas, incluindo présigmoide retrolabiríntica, translabiríntica e petrosectomia total, e a retrossigmoide sejam as mais utilizadas para ressecção destes tumores, não foi realizado até o presente momento estudo comparativo que determine qual abordagem apresenta maior grau de ressecção cirúrgica associada a menor taxa de morbidade. / Petroclival meningiomas are challenging skull base tumors for surgical resection because of its deep location and their relationship to vital neurovascular structures. They are usually benign, but may involve or infiltrate the bone of the skull base, dura, brain stem and all neurovascular structures in this region, making it difficult to completely remove without causing neurological deficits. The aim of this study is to review a surgical series of petroclival meningioma treated in a referral center for skull base tumors, considering the determining factors to the choice of approach. The casuistry was analyzed with retrospective data collection. Due to difficult access, these injuries usually require different surgical approaches and have different surgical difficulties. Although the fronto-orbital-zygomatic, petrous, including retrolabyrinthine pre-sigmoid, translabyrinthine and total petrosectomy, and retrosigmoid are frequently used for resection of these tumors, it has not been realized to date comparative study to determine which approach has greater degree of surgical resection associated with lower morbidity rate.

Over the past two decades a body of evidence concerning residual biological contamination on cleaned surgical instruments has accumulated. This is substantiated by the number of yearly surgery cancellations due to visible residue on instruments in surgical packs and incidences of iatrogenic Creutzfeldt-Jakob disease (iCJD). It is therefore imperative to develop a method of protein detection for use in clinical sterile services departments (SSDs) for monitoring of decontamination quality. This Thesis describes the development and use of an epifluorescence surface scanner (EFScan) technology in the assessment of proteinaceous residue on surgical instruments, by detecting protein pre-labelled with fluorescein isothiocyanate (FITC), and exploratory studies on the feasibility of label-free detection, using intrinsic protein fluorescence. Measurements using FITC labelling showed that residual protein on the order of micrograms can be found on new, single-use instruments (i.e. prior to use). This is comparable to the amount of residual protein found on retired, reusable instruments. To confirm the suitability of fluorescence techniques in the detection and quantification of proteinaceous residue, a blind, pilot study was carried out in conjunction with groups from Queen Mary University and the University of Southampton. Each University used a different labelling and detection method, and results showed good agreement between these methods. This showed that fluorescence is a suitable technique for the detection and quantification of proteinaceous contamination on surgical instruments. The next step in the project focussed on detection of contamination via intrinsic protein fluorescence from tryptophan residues, with a view to elimination of the labelling step. Intrinsic fluorescence of proteins in solution is widely characterised; however, fluorescence characteristics of solid or surface-bound protein have been little studied. Therefore, the characterisation of solid protein fluorescence and the emission characteristics of protein adsorbed onto stainless steel was undertaken. Analysis of the commonly used protein standard bovine serum albumin (BSA) showed that the two tryptophan residues it contains are highly susceptible to photo-oxidation in the solid state, resulting in conversion to the fluorescent photoproducts n-formylkynurenine (NFK) and kynurenine. Therefore, BSA is not suitable for use as a standard in the development of intrinsic fluorescence detection of surface-bound protein. The 72-tryptophan protein fibrinogen, as well as a series of other multi-tryptophan proteins, were assessed and it was found that photo-oxidation of the tryptophan residues did not occur on the irradiation timescale of 1 hour utilized. Therefore, it was concluded that lysozyme or gamma-globulins, a prominent group of serum proteins, would be more suitable candidates as a standard in subsequent research into the intrinsic detection and quantification of proteinaceous contamination. A third study explored the potential use of fluorescence in the early diagnosis of cataract. This involved the fluorescence characterisation of healthy porcine lenses and the use of UV irradiation of the lens to attempt to create cataract in vitro. There was found to be a large variation in fluorescence characteristics from lens to lens, suggesting that fluorophore concentrations can vary significantly. This implies that identification of a suitable standard for the early detection of cataract may be problematic. Attempts to create cataract resulted in the photo-oxidation pathway which had been observed in BSA, and although NFK and kynurenine play a role in cataractogenesis, the accumulation of these photoproducts is not analogous to a natural cataract. It was found that these products could be destroyed by irradiation of the lens at appropriate photo-bleaching wavelengths. However, this also destroyed intrinsic, protective fluorophores within the lens, suggesting that a light-based method of cataract treatment may not be achievable.

The problem of this study was to ascertain (a) the teaching practices of medical-surgical nursing teachers in the clinical laboratory of baccalaureate nursing schools in the State of Texas, and (b) some variables possibly associated with these practices.

Cryptosporidium are protozoan parasites that infect the gastrointestinal epithelium of various vertebrate hosts. The genus has two major phylogenetic groups: a gastric group that infect the epithelium of the stomach and an intestinal group that infect the epithelium of the small and large intestine. Cryptosporidium are transmitted by the faecal-oral route and infect epithelial cells following excystation of the environmental oocyst stage. It has been proposed that excystation of intestinal species is triggered by exposure to the acidic stomach contents, although this has not been verified experimentally. This study aimed to determine whether exposure to stomach contents is necessary for in vivo infection by the intestinal species C. parvum and whether passage through the intestine is necessary for the gastric species C. proliferans to cause infection. It was shown that purified and non-purified oocysts of C. parvum were infectious for SCID mice following surgical inoculation directly into different parts of the small intestine, demonstrating that passage through the stomach is not necessary for infection by this intestinal species. Inoculation of the jejunum resulted in a course of infection similar to oral inoculation. Cryptosporidium proliferans was infectious for na?ve SCID mice following surgical extraction from the stomach of infected SCID mice, demonstrating that passage through the small intestine is not necessary for infection by this gastric species. However, surgical inoculation of C. proliferans oocysts directly into the intestinum tenue did not cause infection.

Neste trabalho foram utilizados os conceitos de célula flexível de manufatura e de automação utilizando a robótica para desenvolver uma célula robotizada de acabamento de instrumentos cirúrgicos forjados, com o objetivo de obter aumento de produção e flexibilizar o sistema de manufatura. Na produção manual de acabamento dos instrumentos cirúrgicos incluídos no estudo são realizados processos de lixamento, eletropolimento, polimento vibratório, jateamento e polimento com manta sintética e escova. Foi identificado que o sistema utilizando trabalho manual restringe a produtividade a um número de pinças insuficiente para atender à demanda do mercado. Desse modo, foi desenvolvida uma célula robotizada de acabamento, com a intenção de suprir a necessidade do aumento de produção dos instrumentos cirúrgicos. Em paralelo ao desenvolvimento da célula flexível de manufatura, estudaram-se os processos de acabamento utilizados, resultando na eliminação de etapas de acabamento no processo automatizado. Com a célula flexível de manufatura desenvolvida se obteve um aumento de produção de 96,87 % e uma redução nos custos de 50,53 % em relação à linha manual. Os produtos cuja manufatura se deseja automatizar são pinças hemostáticas, de apreensão e de campo que foram selecionadas através da análise da demanda produtiva. A matéria-prima utilizada nestes instrumentos é aço inoxidável martensítico, de denominação AISI 420D. O processo de fabricação utilizado nos componentes é o forjamento, que permite a melhora das propriedades mecânicas, modificando a disposição dos constituintes do material deformado. No entanto, foi avaliada de forma experimental a viabilidade de substituição do forjamento pelo corte laser, visando a eliminação do processo de lixamento dos componentes, com consequente aumento na taxa de produção, o que não foi possível devido à menor resistência obtida pelos componentes assim produzidos. / In this study, were used the concepts of flexible cell manufacturing and automation using robotics to develop a finishing in forged surgical instruments robot cell, in order to get increased production and a more flexible manufacturing system. On completion of the manual production of surgical instruments included in the study of processes are performed grinding, electropolishing, vibratory polishing, sandblasting and polishing synthetic blanket and brush. Was identified that the system using manual labor productivity to a limited number of tweezers insufficient to meet market demand. Thus, was developed a robotic finishing cell, with the intention of meeting the need for increasing production of surgical instruments. In parallel to the development of flexible manufacturing cell, were studied the finishing processes used, resulting in the elimination of finishing steps in the automated process. With the flexible manufacturing cell development was obtained an increase of 96.87% and production cost savings of 50.53% compared to the online manual. The products whose manufacture is desirable to automate hemostat, apprehension and field tweezers that were selected by analyzing the production demand. The raw material used in these instruments is martensitic stainless steel, designations AISI 420D. The manufacturing process used in the components is forginig, which allows the improvement of mechanical properties by modifying the arrangement of the constituents of the deformed material. However, it was experimentally evaluated the feasibility of replacing the forging by laser cutting, in order to eliminate the process of grinding the components, with consequent increase in production rate, which was not possible due to a lower resistance obtained by the components thus produced.

Atualmente a International Continence Society (ICS) define IU como qualquer perda involuntária de urina e é considerada um problema social e/ou de higiene valorizando a queixa das pacientes. A prevalência da IU em mulheres adultas tem sido estimada entre 10 e 40 %, e pode piorar com o envelhecimento, paridade e obesidade. Uma doença de baixa morbidade é responsável por até 30% do movimento cirúrgico de um ambulatório de ginecologia; por isso, a indicação precisa do tratamento é fundamental. O tratamento cirúrgico deve ser oferecido para incontinência moderada a severa ou na falha do tratamento clínico. Vários estudos têm mostrado que a IU está associada com a disfunção sexual, relatados por até dois terços das mulheres, no mundo, com sintomas como dispareunia, ressecamento vaginal e dificuldade para atingir o orgasmo, entre outros. Objetivo: O objetivo deste estudo foi comparar a função sexual de mulheres com incontinência urinária, antes e depois do tratamento cirúrgico. Método: Este estudo foi realizado no Hospital de Clínicas de Porto Alegre e na Irmandade Santa Casa de Misericórdia de Porto Alegre entre agosto de 2009 e novembro de 2011. Tratase de um ensaio clinico controlado não randomizado que avaliou a função sexual de mulheres com incontinência urinária utilizando o instrumento Female Sexual Function Index (FSFI) e submetidas a tratamento cirúrgico (Burch ou Sling). A amostra total se constituiu de 38 mulheres que preencheram o questionário FSFI no pré-operatório e seis meses após Intervenção: Cirurgia de Burch ou Sling Instrumentos: Questionário FSFI, variáveis clínicas e demográficas. Resultados: Trinta e oito mulheres foram incluídas no estudo e assinaram o Termo de Consentimento Livre e Esclarecido. A média de idade das mulheres foi 48 anos, todas sexualmente ativas. Oito mulheres fizeram o procedimento cirúrgico tipo Burch e trinta mulheres tipo Sling. No grupo Sling as mulheres eram mais velhas do que as do grupo Burch tinham maior tempo de vida em comum com seus parceiros (24,3 + 11,9) e um IMC de sobrepeso/obesidade (28,4 + 3,3). Não houve diferença estatisticamente significativa no préoperatório nos domínios do FSFI, porém no pós-operatório o escore geral indicou uma melhora da função sexual. Conclusões: Os domínios desejo e excitação melhoraram significativamente após a cirurgia para toda a amostra estudada. Aquelas que apresentaram cistocele tiveram uma melhora da função sexual no domínio dor e desconforto. / Aims: The Female Sexual Function Index (FSFI) is a scale to assess sexual dysfunction in women. This study compared sexual function of women with urinary incontinence before and after surgical treatment. Methods: This nonrandomized clinical controlled trial was conducted in the Hospital de Clínicas de Porto Alegre and in Irmandade Santa Casa de Misericórdia de Porto Alegre from August 2009 to November 2011, to evaluate the sexual function of women with urinary incontinence that underwent surgical treatment (Burch or sling procedure). The sample comprised 38 women that answered the FSFI questionnaire before operation and six months after the intervention. Results: Thirty-eight women were included in the study and signed an informed consent term. Mean age was 48.3 years; all were sexually active, had studied for at least eight years (65.8%), had steady partners whose mean age was 54 years and with whom they had lived for a mean 22.5 years. The desire and arousal domains improved significantly after surgery for all the women included in the study. Conclusions: The patients that had cystocele had an improvement in sexual function in the discomfort and pain domain.

INTRODUÇÃO: as fraturas transtrocanterianas do fêmur são muito frequentes nos idosos, e seu tratamento é eminentemente cirúrgico. Na grande maioria dos casos há a consolidação da fratura, mas os pacientes parecem não evoluir satisfatoriamente do ponto de vista clínico. O objetivo deste estudo é avaliar a qualidade da marcha de pacientes que foram submetidos ao tratamento cirúrgico por uma técnica de fratura transtrocanteriana instável. MATERIAL E MÉTODOS: participaram deste estudo 24 pacientes operados por fratura transtrocanteriana instável do fêmur com utilização do DHS. Os pacientes foram acompanhados prospectivamente, e foi avaliada a qualidade da marcha de pós-operatório e comparada com a de antes da cirurgia, segundo o escore de Robinson. RESULTADOS: no período pré-operatório, 14 pacientes (58,3%) eram do grupo I segundo o escore de marcha de Robinson; 4 (16,7%), do grupo II; 3 (12,5%), do grupo III; 1 (4,2%), do grupo IV; e 2 (8,3%), do grupo V. Todas as fraturas evoluíram para a consolidação, e a taxa de mortalidade foi de 25%. Todos os pacientes foram encaminhados para o mesmo protocolo de reabilitação, e após um período médio de 9,69 meses, 28,6% dos pacientes apresentavam-se no grupo I do escore de Robinson; 23,8%, no grupo II; 4,8%, no grupo III; 23,8%, no grupo IV; e 19% estavam no grupo V. Esses dados mostram que, apesar da alta taxa de consolidação das fraturas, não houve melhora sequer na manutenção da qualidade da marcha dos pacientes, sendo estatisticamente significante (p= 0,003). CONCLUSÕES: as fraturas transtrocanterianas instáveis do fêmur podem ser tratadas com o DHS, apresentando uma alta taxa de consolidação. Entretanto, parecem não evoluir bem do ponto de vista funcional. Esses achados deveriam ser confirmados por outros estudos com maior número de pacientes e avaliando outro tipo de implante. / INTRODUCTION: transtrochanteric fractures of the femur are very frequent in elderly patients, and its treatment is mainly surgical. In most cases the fracture can be consolidated, but patients seem not to have a satisfactory clinical evolution. The objective of this study is to evaluate gait quality of patients who have been submitted to surgical treatment with a technique of unstable transtrochanteric fracture. MATHERIAL AND METHODS: This study evaluated 24 patients who had been operated for unstable transtrochanteric fracture of the femur with the use of DHS. The patients were prospectively followed up, and the postoperative gait quality was evaluated and compared to preoperative gait using Robinson score. RESULTS: In preoperative period, 14 (58.3%) patients belonged to Group I according to Robinson score, 4 (16.7%) belonged to Group II, 3 (12.5%) belonged to Group III, 1 (4.2%) belonged to Group IV, and 2 (8.3%) belonged to Group V. All the fracture evolved to consolidation, and the mortality rate was 25%. All the patients were referred to the same rehabilitation protocol, and after an average period of 9.69 months, 28.6% were in Group I of Robinson score, 23.8% were in Group II, 4.8% in Group III, 23.8% in Group IV, and 19% in Group V. These data show that, despite the high rate of fracture consolidation, there was no improvement even in the maintenance of the patients’ gait quality, being it statistically significant (p= 0.003). CONCLUSIONS: Unstable transtrochanteric fractures of the femur can be treated with DHS, presenting a high consolidation rate. However, they seem not to evolve functionally. These findings should be confirmed by other studies with a higher number of patients who also use another type of implant.

Introdução e Objetivos: A cirurgia traqueal experimental utiliza diversas técnicas para a realização de traqueoplastias. A variabilidade de técnicas pode determinar irregularidades nos resultados obtidos. Este estudo tem como objetivo apresentar um modelo de traqueoplastia em ratos, sob ventilação espontânea, utilizando um molde intraluminal para conferir qualidade e homogeneidade à sutura, mesmo com limitação de recursos. Essas características visam a oferecer substrato adequado para comparação de métodos diferentes propostos para cirurgia traqueal. Material e Métodos: Trinta ratos machos Wistar, com cerca de noventa dias de vida e peso variando entre 326 e 505 gramas foram recrutados para o experimento. Dez animais foram utilizados como pilotos sendo que a destreza técnica e os cuidados para com os animais foram estabelecidos. Os demais vinte animais foram operados para avaliação clínica da permeabilidade da via aérea e identificação de causas de falência do método.Os animais foram anestesiados, e a traquéia cervical foi abordada. Foi ressecado o quarto anel traqueal com preservação da porção membranosa e, a seguir, a traquéia foi entubada de maneira retrógrada para clearance da via aérea e moldagem para a confecção da sutura traqueal. Foi realizada uma traqueoplastia por sutura contínua e, o animal foi extubado. O fator analisado foi o padrão ventilatório tanto no período pós-operatório imediato como no pósoperatório tardio. Resultados: Apenas um animal apresentou insuficiência respiratória imediata após o procedimento e evoluiu a óbito. A causa da disfunção foi a migração do tubo traqueal que não atuou como suporte para a traqueoplastia. Os demais animais apresentaram evolução clínica sem eventos desfavoráveis. Conclusões: O modelo de traqueoplastia proposto, avaliado a partir de parâmetros clínicos, mostrouse viável e reprodutível, podendo ser utilizado para diversos fins em cirurgia traqueal experimental. / Introduction and objectives: This study has the objective to present a tracheoplasty model in rats, in spontaneous ventilation and using an intraluminal stent to secure quality and homogeneity to the suture. And this way offer an adequate substrate to compare different methods proposed to tracheal surgery. Material and methods: thirty male wistar rats, around 90 days of life were included in this study. Ten animals were used as pilots to the study. The last twenty animals were operated for clinical valuation and identification of collapse of the method. The fourth tracheal ring was removed with preservation of the membranous layer and after that the trachea was tubed by reversed way for modeling and confection of the tracheal suture. A tracheoplasty with running suture was accomplished and the tube was removed. The studied factor was the breathing pattern as post – operative period immediately as in the late it. Results: Only one animal had fatal respiratory failure immediately after the surgery. It was caused by the migration of the tracheal tube and this way, do not acting as a stent to the tracheoplasty. The other animals presented good clinical evolution. Conclusions: The proposed tracheoplasty model, evaluated by clinical parameters, presented viable and reproducible and can be used in several tracheal experiments.

A cola de fibrina tem sido utilizada em diferentes procedimentos cirúrgicos como agente hemostático, selante e de suporte adesivo. No entanto, seu emprego na Veterinária ainda é limitado devido à falta de formulações não dependentes dos componentes de origem humana e de validação baseada em necessidades e condições cirúrgicas de animais. Objetivou-se avaliar a viabilidade da produção de cola de fibrina canina com fibrinogênio obtido por crioprecipitação (crio) e precipitação por protamina a partir de fontes plasmáticas mais disponíveis em bancos de sangue e centros hospitalares. Quatro categorias de plasma pobre em plaquetas foram utilizadas: plasma fresco (FR), congelado dentro de oito horas da colheita e processado em menos de uma semana após congelamento; plasma fresco congelado (FFP), com armazenamento inferior a um ano; plasma fresco congelado que ultrapassou um ano de armazenamento (eFFP), e plasma congelado com período entre colheita e congelamento maior que oito horas e de armazenamento superior a um ano (FP). No estudo in vitro de cada técnica, avaliou-se a concentração de fibrinogênio precipitado por meio do método de Clauss, as propriedades reológicas do gel por tromboelastografia (TEG) e as características estruturais do coágulo por microscopia eletrônica de varredura (SEM). O estudo in vivo consistiu da avaliação da praticidade de aplicação e das propriedades hemostáticas e adesivas das colas de fibrina resultantes em fígado e intestino de coelho (Oryctolagus cuniculus). Em avaliação prévia do protocolo de crio quanto ao uso de bolsas ou tubos, o aproveitamento do material inicial não diferiu, mas os tubos se mostraram mais simples, rápidos e homogêneos para o processamento, além de permitirem aumento da concentração final. O protocolo crio em comparação ao de protamina foi superior na precipitação de fibrinogênio coagulável nas avaliações de Clauss e TEG. Os coágulos formados se mostraram semelhantes entre os dois protocolos na SEM, no modelo de hemostasia hepática e na adesão à serosa intestinal. O uso de aprotinina com o protocolo de protamina não prejudicou a aplicação da cola sobre o intestino. Na crio, plasmas com maior tempo de armazenamento (eFFP, FP) se mostraram significativamente superiores aos mais frescos (FFP, FR) nas análises por Clauss e TEG. Não foi possível identificar diferenças estatísticas entre os tipos de plasma no protocolo protamina em nenhum dos parâmetros avaliados. Estudos adicionais e ajustes nos testes para avaliação de soluções concentradas são necessários para determinação do efeito dos protocolos e tempo de armazenamento do plasma congelado sobre o fibrinogênio precipitado e demais componentes plasmáticos na cola de fibrina. Adequações e pesquisas ainda são necessárias para aproveitamento da precipitação de fibrinogênio por protamina e a partir de plasma fresco com a finalidade de obtenção rápida de cola de fibrina. Bolsas de plasma menos requisitadas em bancos de sangue veterinários representam uma fonte importante de fibrinogênio para a produção de cola de fibrina canina em centros hospitalares apropriadamente equipados, viabilizando seu uso em diferentes aplicações cirúrgicas e pesquisas relacionadas. / Fibrin glue (FG) has been widely used in surgery for hemostatic, adhesive, sealant, and would healing support. In veterinary surgery, however, its use has been hindered by lack of specie-specific formulations and validation of its properties and biological characteristics. This study evaluated methods of fibrinogen precipitation from canine plasma envisioning autologous and allogeneic FG production for surgical use. The efficacy of cryo and protamine fibrinogen precipitation methods in producing canine FG was assessed by analysis on feasibility of each protocol with most available canine plasma sources, rheological and structural characteristics of the resultant FG clot and the hemostatic and adhesive properties of FG during in vivo application. The plasma categories studied included fresh plasma (FR), obtained and frozen within 8 hours from blood collection and processed within a week; fresh frozen plasma (FFP), frozen within 8 hours from blood collection and stored for up to a year; expired fresh frozen plasma (eFFP), plasma frozen within 8 hours from blood collection but stored for more than a year; and, frozen plasma (FP), which was frozen after 8 hours from collection and stored for more than a year. Comparison of cryoprecipitation among plasma types was previously performed in both 120-mL bags and 50-mL tubes and analyzed by Clauss. Total precipitation capacity did not differ significantly between bags and tubes. Nevertheless, the processing was more easily and homogeneously performed in tubes and allowed tailoring the final concentration. Cryoprecipitation generated better results in Clauss and TEG in comparison to protamine protocol. The resultant fibrin glue clots of cryo- and protamine-precipitation showed similar ultrastructure in scanning electron microscopy (SEM) and performance in the in vivo evaluations with the rabbit hepatic and intestinal incision models. The use of aprotinin in the protamine clot seemed beneficial in the intestinal evaluation. With cryoprecipitation, eFFP and FP were superior to FFP in the assessments performed by Clauss and TEG. Fresh plasma performed poorly with cryoprecipitation. Significant differences were not detected among plasma categories processed with protamine precipitation in any of the assays performed. While cryoprecipitation was more reliable regarding homogeneity and capacity to increase final fibrinogen concentration, protamine protocol was faster and simpler considering the equipment required. Although, older plasma units generated significantly more cryoprecipitated and/or clottable fibrinogen, further studies are needed to validate the assays with such high concentrated solutions and to elucidate the effect of freezing storage on precipitation and clottability of fibrinogen intended for FG production. Adjustments on protamine protocol and improvements on fibrinogen precipitation from fresher plasma sources would support the use of autologous or allogeneic plasma for on-site production of canine FG. Veterinary hospitals, blood banks, and patients can benefit from usage of surplus plasma units for FG production aiming surgical and scientific needs.

This Thesis develops a mathematical model for predicting the thermal response in the surgical drilling of bone. The model accounts for the bone, chip and drill bit interactions by providing a detailed account of events within a cylindrical control volume enveloping the drill, the cut bone chip within the drill bit flute and the solid bone. Lumped parameter approach divides the control volume into a number of cells and cells within the sub-volumes representing the drill solid, the bone chip and the bone solid are allowed to interact. The contact mechanics of rough surfaces is used to model chip-flute and chip-bone frictional interaction. In this way not only the quantification of friction due to sliding contact of chip-flute and chip-bone rough surface contact are treated, but also the contact thermal resistances between the rubbing surfaces are included in the model. A mixed combination of constant and adaptive mesh is employed to permit the simulation of the heat transfer as the drill bit penetrates deeper into the bone during a drilling process. Using the model the effect of various parameters on the temperature rise in bone, drill and the chip are investigated. It is found that maximum temperature within the bone occurs at the location adjacent to the corner of the drill-tip and drill body. The results of the model are found to agree favorably with the experimental measurements reported in the existing literature on surgical drilling.