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2.
Med J Malaysia ; 76(2): 183-189, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33742626

RESUMO

INTRODUCTION: In recent years, many unresolved issues pertaining to house officers in Malaysia have led to a longer waiting time and a 'glut' of medical graduates with a surprising 20% dropout amongst those who join the housemanship programme. This appears to reflect the changing times, mindsets and work expectations of millennials who comprise this cohort reflecting a need to consider possibilities of career shifts especially so in these uncertain times. This study explores the perceptions, awareness and interest in alternative career options amongst recent graduates and house officers. MATERIALS AND METHODS: This was a study done between 2018 and 2019 using a questionnaire which was shared on various social platforms. Data analysis was done using Excel spreadsheet. RESULTS: A total of 450 house officers and 657 medical graduates responded. Expectedly 66.8% claimed lifelong passion whilst another 12.1% claimed family influence as their reason to do medicine. Most were aware of their career challenges and 40% of them were keen to consider career change and reskilling indicating a possible shift from traditional expectations of a medical career. CONCLUSION: Whilst medicine is often considered a true calling, current challenges will require mental and emotional flexibility to explore other career opportunities. Thus, engagement programmes should be directed at medical graduates and house officers to identify and support those open to career transitions. This will help address current issues of internship bottleneck and rising dropout rates amongst internees. Early career change engagements will give them insight into their true career goals whilst opening up opportunities for those who wish to change.


Assuntos
Internato e Residência , Medicina , Atitude do Pessoal de Saúde , Escolha da Profissão , Humanos , Malásia , Inquéritos e Questionários
3.
J Laryngol Otol ; 131(9): 813-816, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28841131

RESUMO

OBJECTIVE: To evaluate the clinicopathological and mycological manifestations of fungal rhinosinusitis occurring in the Tengku Ampuan Rahimah Hospital, in Klang, Malaysia, which has a tropical climate. METHODS: Records of patients treated from 2009 to 2016 were analysed retrospectively. Data from the records were indexed based on age, gender, clinical presentations, symptom duration, clinical signs and mycological growth. RESULTS: Of 80 samples, 27 (33.75 per cent) had fungal growth. Sixteen patients were classified as having non-invasive fungal rhinosinusitis and 11 as having invasive fungal rhinosinusitis. The commonest clinical presentation was nasal polyposis in non-invasive fungal rhinosinusitis patients (p < 0.05) and ocular symptoms in invasive fungal rhinosinusitis patients (p < 0.05). The commonest organism was aspergillus sp. (p < 0.05) in non-invasive fungal rhinosinusitis and mucorales in invasive fungal rhinosinusitis. CONCLUSION: There is an almost equal distribution of both invasive and non-invasive fungal rhinosinusitis, as seen in some Asian countries. Invasive fungal rhinosinusitis, while slightly uncommon when compared to non-invasive fungal rhinosinusitis, is potentially life threatening, and may require early and extensive surgical debridement. The clinical presentation of nasal polyposis was often associated with non-invasive fungal rhinosinusitis, whereas ocular symptoms were more likely to be associated with invasive fungal rhinosinusitis.


Assuntos
Infecções Fúngicas Invasivas/epidemiologia , Micoses/epidemiologia , Rinite/microbiologia , Sinusite/microbiologia , Adulto , Idoso , Feminino , Humanos , Malásia/epidemiologia , Masculino , Pessoa de Meia-Idade , Micoses/classificação , Estudos Retrospectivos , Centros de Atenção Terciária , Clima Tropical
4.
Hong Kong Med J ; 22(1): 23-9, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26680156

RESUMO

INTRODUCTION: Sarcopenia and osteoporosis are age-related declines in the quantity of muscle and bone, respectively. Both contribute in disability, fall, and hip fracture in the elderly. This study reported the prevalence of sarcopenia in Chinese geriatric patients with hip fracture, and the correlation between relative appendicular skeletal muscle mass index and other factors. METHODS: This case series was conducted in Kowloon West Cluster Orthopaedic Rehabilitation Centre in Hong Kong. Data of all geriatric patients with primary hip fracture admitted to the above Centre from June to December 2014 were studied. Isometric grip strength, the maximal handgrip strength, was measured using a JAMAR hand dynamometer. Body composition including appendicular and whole-body lean body mass was measured using dual-energy X-ray absorptiometry. Pearson's correlation was used to examine the correlation between relative appendicular skeletal muscle mass index and other factors. RESULTS: A total of 239 patients with a mean age of 82 years were included in the study. Stratifying patients as male or female, the mean (± standard deviation) hand grip strength was 20.6 ± 7.3 kg and 13.6 ± 4.5 kg, the mean relative appendicular skeletal muscle mass index was 5.72 ± 0.83 kg/m(2) and 4.87 ± 0.83 kg/m(2), and the mean hip bone mineral density was 0.696 ± 0.13 g/cm(2) and 0.622 ± 0.12 g/cm(2), respectively. The prevalence of sarcopenia based on relative appendicular skeletal muscle mass index and hand grip strength according to the Asian Working Group for Sarcopenia definition was 73.6% in males and 67.7% in females. According to the European Working Group on Sarcopenia definition, the prevalence of pre-sarcopenia was 20.8% in males and 12.4% in females. Relative appendicular skeletal muscle mass index was positively correlated with hand grip strength, body weight, hip bone mineral density, body mass index, and total fat mass in males; and hand grip strength, body weight, body height, body mass index, and total fat mass in females. Except for body height in females, all correlations were statistically significant. CONCLUSION: The prevalence of sarcopenia was very high in geriatric hip fracture patients, and much higher than that in community-dwelling elderly population. Apart from the need to prescribe osteoporosis medicine, sarcopenia screening and treatment should be offered and is essential to reduce subsequent fall, subsequent fracture, fracture-related complications and economic burden to Hong Kong.


Assuntos
Fraturas do Quadril , Sarcopenia , Absorciometria de Fóton/métodos , Idoso , Idoso de 80 Anos ou mais , Composição Corporal , Estatura , Índice de Massa Corporal , Peso Corporal , Feminino , Força da Mão , Fraturas do Quadril/epidemiologia , Fraturas do Quadril/etiologia , Hong Kong/epidemiologia , Humanos , Masculino , Prevalência , Sarcopenia/complicações , Sarcopenia/diagnóstico , Sarcopenia/epidemiologia , Estatística como Assunto
6.
Br J Ophthalmol ; 94(1): 85-7, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19628488

RESUMO

OBJECTIVE: To evaluate the influence of socio-economic factors on severity of glaucoma at presentation METHODS: All newly diagnosed glaucoma patients at the University Hospitals-NHS, Aberdeen and South Glasgow University Hospitals-NHS, in 2006, were included. Glaucoma was severe at presentation if there was a repeatable visual-field loss with a mean deviation index greater than 12 dB in the Humphreys visual fields test or an absolute paracentral scotoma within the central 5 degrees of the visual fields. Home address was used to determine the Scottish Index of Multiple Deprivation (SIMD) rank. The SIMD rank, demographics and severity of glaucoma at presentation were investigated using general linear modelling. RESULTS: There were 48 patients with severe glaucoma and 74 patients with non-severe glaucoma. In four, the severity could not be determined. Severity of glaucoma at presentation was significantly associated with SIMD rank, being most severe in patients from areas with the lowest ranks (p = 0.026). Age was a significant factor (p = 0.024), with severe glaucoma being more common in elderly patients. CONCLUSIONS: Age and socio-economic deprivation were associated with severity of glaucoma at presentation, with patients from areas of higher socio-economic deprivation presenting with more advanced glaucoma.


Assuntos
Glaucoma/epidemiologia , Áreas de Pobreza , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Glaucoma/complicações , Glaucoma/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Escócia/epidemiologia , Escotoma/epidemiologia , Escotoma/etiologia , Índice de Gravidade de Doença , Fatores Socioeconômicos , Transtornos da Visão/epidemiologia , Transtornos da Visão/etiologia , Transtornos da Visão/fisiopatologia , Campos Visuais
7.
Int J Med Robot ; 5(1): 51-8, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19145573

RESUMO

BACKGROUND: We introduce the first robotic ultrasound-guided prostate intervention device and evaluate its safety, accuracy and repeatability. METHODS: The robotic positioning system (RPS) determines a target's x, y and z axes. It is situated with a biplane ultrasound probe on a mobile horizontal platform. The integrated software acquires ultrasound images for three-dimensional (3D) modelling, coordinates target planning and directs the RPS. RESULTS: The egg phantom evaluates the software's safety and workflow protocol. Two random targets are planned in each quadrant and biopsy needles are inserted. All were within three separate eggs. Metal wire tips are targeted and their distances from the biopsy needle tips are measured. With 20 wires, < 1 mm accuracy is obtained. Repeatability is demonstrated when previous positions are returned to with similar accuracy. CONCLUSION: Our device demonstrates safety in a defined boundary with a repeatable accuracy of < 1 mm. It can be used for accurate prostate biopsy and treatment delivery.


Assuntos
Desenho de Equipamento/instrumentação , Imagens de Fantasmas , Próstata/diagnóstico por imagem , Robótica/instrumentação , Cirurgia Assistida por Computador/instrumentação , Biópsia por Agulha/instrumentação , Biópsia por Agulha/métodos , Calibragem , Desenho de Equipamento/efeitos adversos , Humanos , Imageamento Tridimensional/instrumentação , Imageamento Tridimensional/métodos , Masculino , Próstata/patologia , Reprodutibilidade dos Testes , Software , Ultrassonografia
8.
Eye (Lond) ; 23(2): 351-5, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18049484

RESUMO

PURPOSE: To assess the quality of referrals from community optometrists in the northeast of Scotland to the hospital glaucoma service before and after the implementation of the new General Ophthalmic Services (GOS) contract in Scotland. METHODS: Retrospective study encompassing two 6-month periods, one before the implementation of the new GOS (Scotland) contract in April 2006 (from June to November 2005), and the other after (from June to November 2006). The community optometrist referral forms and hospital glaucoma service notes were reviewed. Comparisons were performed using the t-test and chi (2)-test. RESULTS: In all, 183 referrals were made during the first 6-month period from June to November 2005, and 120 referrals were made during the second 6-month period from June to November 2006. After the introduction of the new GOS contract, there was a statistically significant increase in true-positive referrals (from 18.0 to 31.7%; P=0.006), decrease in false-positive referrals (from 36.6 to 31.7%; P=0.006), and increase in the number of referrals with information on applanation tonometry (from 11.8 to 50.0%; P=0.000), dilated fundal examination (from 2.2 to 24.2%; P=0.000), and repeat visual fields (from 14.8 to 28.3%; P=0.004) when compared to the first 6-month period. However, only 41.7% of referrals fulfilled the new GOS contract requirements, with information on applanation tonometry the most commonly missing. CONCLUSIONS: After the implementation of the new GOS (Scotland) contract in April 2006, there has been an improvement in the quality of the glaucoma referrals from the community optometrists in the northeast of Scotland, with a corresponding reduction in false-positive referrals. Despite the relatively positive effect so far, there is still scope for further improvement.


Assuntos
Serviços Contratados/normas , Glaucoma/diagnóstico , Optometria/normas , Encaminhamento e Consulta/normas , Idoso , Serviços de Saúde Comunitária/organização & administração , Serviços Contratados/organização & administração , Técnicas de Diagnóstico Oftalmológico/normas , Feminino , Glaucoma/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Optometria/organização & administração , Encaminhamento e Consulta/organização & administração , Estudos Retrospectivos , Escócia/epidemiologia
9.
Comput Aided Surg ; 12(6): 366-70, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18066952

RESUMO

In contemporary brachytherapy procedures, needle placement at the desired target is challenging for a variety of reasons. A robot-assisted brachytherapy system can potentially improve needle placement and seed delivery, resulting in enhanced therapeutic outcome. In this paper we present a robotic system with 16 degrees of freedom (DOF) (9 DOF for the positioning module and 7 DOF for the surgery module) that has been developed and fabricated for prostate brachytherapy. Strategies to reduce needle deflection and target movement were incorporated after extensive experimental validation. Provision for needle motion and force feedback was included in the system to improve robot control and seed delivery. Preliminary experimental results reveal that the prototype system is sufficiently accurate in placing brachytherapy needles.


Assuntos
Braquiterapia/métodos , Próstata , Robótica/métodos , Humanos , Masculino , Próstata/diagnóstico por imagem , Neoplasias da Próstata/radioterapia , Robótica/instrumentação , Ultrassonografia
10.
Clin Exp Immunol ; 150(1): 169-78, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17680826

RESUMO

Data indicate that appendicectomy for intra-abdominal inflammation protects against inflammatory bowel disease (IBD). This suggests an important role for the appendix in mucosal immunity. There is no established model of appendicitis. We therefore developed a murine model of appendicitis and examined the effect of inflammation on appendiceal lymphocyte constituents. The caecal patch of specific pathogen-free (SPF)-Balb/c mice was transformed into an obstructed 'appendiceal pouch' by standardized suction and band ligation. Mice were killed and 'pouches' removed for histology and phenotypic analysis of leucocytes by flow cytometry. Serum C-reactive protein (CRP) was determined by enzyme-linked immunosorbent assay. All 'pouches' developed features resembling human appendicitis - mucosal ulceration, transmural inflammation with neutrophils, lymphocytes and occasional eosinophils, and serositis. These changes were most evident between days 7 and 10. There was significant elevation of serum CRP (8.0 +/- 0.3 ng/ml to 40.0 +/- 3.1 ng/ml; P < 0.01), indicating systemic inflammation. Following the initial neutrophil-predominant response, there was an increase in CD4(+) (15.3% +/- 1.2% to 31.0 +/- 2.0%; P < 0.01) and CD8(+) T lymphocytes (3.7% +/- 0.6% to 9.2 +/- 0.8%; P < 0.01). CD25(+) forkhead box P3 (FoxP3)(+) regulatory T lymphocytes were increased by 66% (P < 0.01). Furthermore, significant increases in CD8(+) FoxP3(+) regulatory T lymphocytes were restricted to younger mice (age < 10 weeks, P < 0.003). This is the first description of a murine model of appendicitis. Inflammation resulted in T lymphocyte accumulation associated with an increase in regulatory T lymphocytes, which might explain the age-dependent protective phenomenon. Further exploration will provide insights into the mechanisms of intestinal immune homeostasis and the immunopathogenesis of IBD.


Assuntos
Apendicite/imunologia , Modelos Animais de Doenças , Subpopulações de Linfócitos/imunologia , Fatores Etários , Animais , Apendicite/etiologia , Apendicite/patologia , Apêndice/imunologia , Proteína C-Reativa/metabolismo , Ceco/patologia , Imunidade nas Mucosas , Imunofenotipagem , Mucosa Intestinal/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Organismos Livres de Patógenos Específicos , Subpopulações de Linfócitos T/imunologia
11.
Hong Kong Med J ; 13(2): 122-30, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17406039

RESUMO

OBJECTIVES: To compare the clinical characteristics of aortic dissection in Hong Kong with the International Registry of Aortic Dissection, and to evaluate the sensitivity of the Accident and Emergency Department in diagnosing aortic dissection and its role in aortic dissection management. DESIGN: Retrospective observational study. SETTING: Regional public hospital, Hong Kong. PATIENTS: Newly diagnosed aortic dissection patients attending the Accident and Emergency Department from 2002 to 2005 inclusive. MAIN OUTCOME MEASURES: Correct diagnosis in Accident and Emergency Department, tertiary unit transfer, and in-patient mortality. RESULTS: Twenty-eight patients were found to have aortic dissection, with an estimated annual incidence of 2.1 per 100,000 inhabitants. The sensitivity of Accident and Emergency Department in diagnosing aortic dissection was 54%; 11% of the patients were diagnosed at postmortem examination. Compared to the International Registry of Aortic Dissection, the patients in this Tseung Kwan O Hospital study had less abrupt and less severe pain, less chest pain, and a lower proportion were operated on. Higher mortality was associated with age 70 years or older (odds ratio=6.4), female gender (21.0), known hypertension (3.8), systolic blood pressure below 100 mm Hg (6.0), aortic dissection not diagnosed in the Accident and Emergency Department (3.2), and the patient not reaching tertiary unit (33.8). The hourly cumulative mortality rate was 1.32%. The group of aortic dissections diagnosed in the Accident and Emergency Department had 55.1% more transfer to tertiary unit (95% confidence interval, 14.4-79.1%; P=0.006), 84.5 hours less transfer time (95.3-263.6 hours; P=0.232), and 27.2% lower mortality (12.6-58.6%; P=0.246). The yield rate of contrast computed tomography of thorax was 43%. CONCLUSIONS: Diagnosing aortic dissection in the Accident and Emergency Department enabled optimal disposition and lower in-patient mortality.


Assuntos
Aneurisma Aórtico/diagnóstico , Aneurisma Aórtico/mortalidade , Dissecção Aórtica/diagnóstico , Dissecção Aórtica/mortalidade , Serviço Hospitalar de Emergência , Fatores Etários , Idoso , Tontura/etiologia , Dispneia/etiologia , Feminino , Hong Kong/epidemiologia , Mortalidade Hospitalar , Humanos , Hipertensão/epidemiologia , Masculino , Pessoa de Meia-Idade , Dor/etiologia , Radiografia Torácica/estatística & dados numéricos , Estudos Retrospectivos , Fatores Sexuais , Análise de Sobrevida , Síncope/etiologia , Sístole , Vômito/etiologia
12.
Med J Malaysia ; 62(3): 259-60, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18246923

RESUMO

Patients with bleeding diatheses can present in a variety of clinical situations. When these patients manifest with ocular complications, their management can be challenging. We describe a case of acute angle closure glaucoma secondary to subretinal haemorrhage, with myelodysplasia as a predisposing factor.


Assuntos
Glaucoma de Ângulo Fechado/etiologia , Defeitos do Tubo Neural/complicações , Doença Aguda , Idoso de 80 Anos ou mais , Feminino , Glaucoma de Ângulo Fechado/tratamento farmacológico , Glaucoma de Ângulo Fechado/patologia , Glaucoma de Ângulo Fechado/cirurgia , Humanos , Malásia
13.
Eye (Lond) ; 21(1): 29-32, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16200056

RESUMO

AIM: To assess the effect of mobile telephone electromagnetic interference on electronic ophthalmic equipment. METHODS: Prospective audit with mobile telephones placed at distances of 3 m, 1 m, and 30 cm from, and in contact with, electronic ophthalmic equipment. Any interruption or cessation of the function of the ophthalmic device was assessed with the mobile telephones in standby, and in dialling or receiving modes. Any alterations of displayed digital figures or numbers were also assessed. RESULTS: A total of 23 electronic ophthalmic devices in two hospital ophthalmology outpatient departments were evaluated. All six mobile telephones used, and 22 (95.7%) of the 23 ophthalmic equipment evaluated had the Conformité Européene (CE) mark. No device showed any interruption or cessation of function. There were no alterations of displayed digital figures or numbers. The only effect of any kind was found with four instruments (1 non-CE marked), where there was temporary flickering on the screen, and only occurred when the mobile telephones were dialling or receiving at a distance of 30 cm or less from the instruments. CONCLUSION: This study shows that among the electronic ophthalmic devices tested, none suffered failure or interruption of function, from mobile telephone interference. Although not comprehensive for all ophthalmic equipment, the results question the need for a complete ban of mobile telephones in ophthalmic departments. It highlights the need for a controlled, objectively measured study of the clinically relevant effects of mobile telephones in the ophthalmology outpatient setting.


Assuntos
Telefone Celular , Técnicas de Diagnóstico Oftalmológico/instrumentação , Campos Eletromagnéticos , Eletrônica Médica/instrumentação , Procedimentos Cirúrgicos Oftalmológicos/instrumentação , Técnicas de Diagnóstico Oftalmológico/normas , Falha de Equipamento , Segurança de Equipamentos/normas , Humanos , Procedimentos Cirúrgicos Oftalmológicos/normas , Ambulatório Hospitalar , Estudos Prospectivos
14.
Conf Proc IEEE Eng Med Biol Soc ; 2005: 5766-70, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-17281568

RESUMO

Precise interstitial intervention is essential for many medical diagnostic and therapeutic procedures. But accurate insertion and placement of surgical needle in soft tissue is quite challenging. The understanding of the interaction between surgical needle and soft tissue is very important to develop new devices and systems to achieve better accuracy and to deliver quality treatment. In this paper we present the effects of velocity (linear, rotational, and oscillatory) modulation on needle force and target deflection. We have experimentally verified our hypothesis that needle insertion with continuous rotation reduces target movement and needle force significantly. We have observed little changes in force and target deflection in rotational oscillation (at least at lower frequency) of the needle.

15.
J Urol ; 171(4): 1482-6, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15017203

RESUMO

PURPOSE: We determined the ability of combined endorectal magnetic resonance imaging (MRI) and magnetic resonance spectroscopic imaging (MRSI) to detect prostate cancer foci prospectively in men with prior negative transrectal ultrasound (TRUS) prostate biopsy. MATERIALS AND METHODS: Endorectal MRI with spectroscopy was performed in 24 consecutive patients with 1 or more prior negative TRUS prostatic biopsies for persistently increased prostate specific antigen and/or abnormal digital rectal examination. All studies were interpreted by a dedicated radiologist who reported areas of interest in the peripheral zone as normal, equivocal or suspicious on MRI and MRSI separately. Equivocal and suspicious areas were then correlated with a 3-dimensional prostate model. All patients underwent a standard TRUS 10-core peripheral zone biopsy with up to 4 additional biopsies targeted at the equivocal or suspected sites. RESULTS: Prostate cancer was detected in 7 of 24 subjects (29.2%). Considering the equivocal category as test negative the sensitivity, specificity, positive and negative predictive values, and the accuracy of MRI, MRSI and combined MRI/MRSI for the detection of prostate cancer were 57.1%, 57.1% and 100.0%, 88.2%, 82.4% and 70.6%, 66.7%, 57.1% and 58.3%, 83.3%, 82.1% and 100%, and 79.2%, 75.0% and 79.2%, respectively. The site of positive biopsy correlated correctly in 50% and 28.6% of MRI and MRSI labeled suspicious cores, respectively. CONCLUSIONS: MRI and MRSI have the potential to identify cancer foci and direct TRUS in patients with a previous negative TRUS biopsy. Further, larger studies are required to quantify the amount of benefit.


Assuntos
Biópsia por Agulha/métodos , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética , Neoplasias da Próstata/diagnóstico , Idoso , Algoritmos , Reações Falso-Positivas , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Estudos Prospectivos , Neoplasias da Próstata/diagnóstico por imagem , Reto , Ultrassonografia
16.
IEEE Trans Biomed Eng ; 48(10): 1125-33, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11585036

RESUMO

Computer-Assisted transurethral laser resection of the prostate (CALRP) is a treatment modality that was designed and developed based on an integrated system of computer, robotics and laser technology in association with a minimally invasive surgery known as laser transurethral resection of the prostate (LRP). CALRP possesses complementary capabilities that could remedy many of the problems faced by surgeons in conventional LRP by delivering a treatment with repeatability and reliability. The work deals primarily in determining the feasibility study of the computer-assisted lasing motion plan (planned motion sequence controlled by a program) for LRP. A theoretical motion plan that analyzes numerically the lasing motion of the fiber was designed by calculating the profile removal rate and in vitro experiments conducted on human cadaveric prostate to verify and validate the designed motion plan. The novel motion plan, which was executed experimentally using the LaserTrode lightguide, accomplished the objective of resecting the enlarged prostate with the aid of computer and robotics technology.


Assuntos
Terapia a Laser/instrumentação , Próstata/cirurgia , Robótica , Terapia Assistida por Computador/instrumentação , Ressecção Transuretral da Próstata/instrumentação , Cadáver , Simulação por Computador , Desenho de Equipamento , Humanos , Masculino , Imagens de Fantasmas
17.
J Antimicrob Chemother ; 47(5): 655-8, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11328779

RESUMO

Ciprofloxacin-susceptible (n = 7) and -resistant (MIC >or=4 mg/L) (n = 15) clinical isolates of Streptococcus pneumoniae from diverse sources in Hong Kong were studied for target site modifications and efflux phenotype. Reserpine-inhibited efflux of ciprofloxacin and/or levofloxacin was common in both susceptible and non-susceptible isolates. The ParC substitutions K137N and/or S79F or Y were associated with increased ciprofloxacin MICS. The GyrA substitution S81F was only found in isolates with full resistance to ciprofloxacin (MIC >or=16 mg/L) and levofloxacin (MIC >or=8 mg/L). Among clinical isolates of S. pneumoniae, accumulation of target site mutations in strains with an efflux mechanism was associated with increasing MICs of fluoroquinolones.


Assuntos
Anti-Infecciosos/farmacologia , Proteínas de Bactérias/genética , Streptococcus pneumoniae/efeitos dos fármacos , Substituição de Aminoácidos , Transporte Biológico , Resistência Microbiana a Medicamentos/genética , Resistência Microbiana a Medicamentos/fisiologia , Fluoroquinolonas , Humanos , Testes de Sensibilidade Microbiana , Mutação , Fenótipo , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/metabolismo
18.
J Biomed Opt ; 6(2): 244-51, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11375736

RESUMO

A longer operating time and steeper learning curve in mastering the techniques for transurethral laser resection of the prostate are the main problems faced by surgeons in addition to the existing ones in standard transurethral resection of the prostate (TURP). However, these disadvantages can be alleviated with the introduction of a treatment procedure designed and developed based on an integrated system of computer, robotics and laser technology. In vitro experiments were carried out to determine variables affecting the vaporization and coagulation lesions, in order to study the effectiveness and feasibility of robotics for this procedure. Human cadaveric prostates and fresh tauted chicken breast tissues were irradiated with different parameters using the LaserTrode lightguide in contact with the tissue. The effects of irrigant flow rate, fiber/tissue angle of inclination, number of passes, direction, speed and power of lase on the volume of tissue vaporized and coagulated, were assessed. The final phase of the experiments includes executing the robotic motion plan for the laser resection procedure on the human cadaveric prostate tissue embedded in an anatomically alike prostate phantom. It was concluded from our study that power and speed of lase are the most significant parameters influencing the volume of the vaporized and coagulated lesion. Comparison of removal rate using the new treatment procedure of robotic laser resection of the prostate with TURP and HoLRP evinced equivalent results.


Assuntos
Terapia a Laser/instrumentação , Terapia a Laser/métodos , Iluminação/instrumentação , Próstata/cirurgia , Robótica , Animais , Cadáver , Galinhas , Desenho de Equipamento , Estudos de Viabilidade , Feminino , Humanos , Masculino , Músculo Esquelético/patologia , Músculo Esquelético/cirurgia , Fatores de Tempo
19.
Proc Inst Mech Eng H ; 215(1): 51-9, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11323985

RESUMO

Magnetic trackers are widely used position/orientation measurement devices in interactive computer systems. These trackers output six-degree-of-freedom position and orientation of their receiver coordinates with respect to their transmitter coordinates. It is a potential solution for real-time position/orientation measurement in an augmented reality system for therapy (ART). However, an obstruction to be overcome is that a magnetic tracker is vulnerable to measurement inaccuracy caused by magnetic field distortions (including ferric and non-ferric distortions) when it is used in metallic environments. The purpose of this paper is to discuss calibration methods used to compensate distortions produced by metallic objects which are moving during the measurement procedure, but fixed with a receiver. Past work on the calibration of magnetic trackers has concentrated on static distortions, which are produced by stationary metallic objects in the environment. Compared with static distortions, in this paper a relatively dynamic situation is considered where the distortion is not constant with time. However, the location of the metallic objects is reflected in the outputs of the receiver so that the distortion can be compensated. This type of distortions, which is called 'quasi-static distortion' in this paper, is common in an ART. Compensation of quasi-static distortion is more complicated than that of static distortion and has not been mentioned in past publications. Some new compensation methods for quasi-static distortion will be introduced here. The results demonstrate that the methods are capable of significantly reducing quasi-static distortions.


Assuntos
Calibragem , Magnetismo , Terapia Assistida por Computador , Simulação por Computador , Modelos Teóricos , Interface Usuário-Computador
20.
J Ultrasound Med ; 19(11): 771-82, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11065266

RESUMO

This paper describes the development of a model-based boundary recognition system for transrectal prostate ultrasonographic images. It consists of two techniques: boundary modeling and boundary searching with model constraints. To achieve higher specificity of the model, a method called feature modeling is derived from the existing point distribution modeling method. To improve the robustness of the searching technique, the genetic algorithm is used. Incremental genetic algorithm with crowding replacement and binary string chromosome type was found experimentally to give good search results. It was shown that the system could recognize the boundary with considerable accuracy and consistency within a few minutes in transrectal ultrasonographic images taken from approximate middle position of the prostate.


Assuntos
Algoritmos , Modelos Genéticos , Modelos Estatísticos , Próstata/diagnóstico por imagem , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Distribuição Normal , Variações Dependentes do Observador , Ultrassonografia
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