Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 145
Filtrar
1.
PLoS One ; 19(7): e0306700, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38990841

RESUMEN

Cells and microorganisms are motile, yet the stationary nature of conventional microscopes impedes comprehensive, long-term behavioral and biomechanical analysis. The limitations are twofold: a narrow focus permits high-resolution imaging but sacrifices the broader context of organism behavior, while a wider focus compromises microscopic detail. This trade-off is especially problematic when investigating rapidly motile ciliates, which often have to be confined to small volumes between coverslips affecting their natural behavior. To address this challenge, we introduce Trackoscope, a 2-axis autonomous tracking microscope designed to follow swimming organisms ranging from 10µm to 2mm across a 325cm2 area (equivalent to an A5 sheet) for extended durations-ranging from hours to days-at high resolution. Utilizing Trackoscope, we captured a diverse array of behaviors, from the air-water swimming locomotion of Amoeba to bacterial hunting dynamics in Actinosphaerium, walking gait in Tardigrada, and binary fission in motile Blepharisma. Trackoscope is a cost-effective solution well-suited for diverse settings, from high school labs to resource-constrained research environments. Its capability to capture diverse behaviors in larger, more realistic ecosystems extends our understanding of the physics of living systems. The low-cost, open architecture democratizes scientific discovery, offering a dynamic window into the lives of previously inaccessible small aquatic organisms.


Asunto(s)
Microscopía , Microscopía/métodos , Microscopía/instrumentación , Microscopía/economía , Animales , Amoeba/fisiología , Locomoción/fisiología , Natación/fisiología
2.
PLoS One ; 19(6): e0304085, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38905190

RESUMEN

In a clinical context, conventional optical microscopy is commonly used for the visualization of biological samples for diagnosis. However, the availability of molecular techniques and rapid diagnostic tests are reducing the use of conventional microscopy, and consequently the number of experienced professionals starts to decrease. Moreover, the continuous visualization during long periods of time through an optical microscope could affect the final diagnosis results due to induced human errors and fatigue. Therefore, microscopy automation is a challenge to be achieved and address this problem. The aim of the study is to develop a low-cost automated system for the visualization of microbiological/parasitological samples by using a conventional optical microscope, and specially designed for its implementation in resource-poor settings laboratories. A 3D-prototype to automate the majority of conventional optical microscopes was designed. Pieces were built with 3D-printing technology and polylactic acid biodegradable material with Tinkercad/Ultimaker Cura 5.1 slicing softwares. The system's components were divided into three subgroups: microscope stage pieces, storage/autofocus-pieces, and smartphone pieces. The prototype is based on servo motors, controlled by Arduino open-source electronic platform, to emulate the X-Y and auto-focus (Z) movements of the microscope. An average time of 27.00 ± 2.58 seconds is required to auto-focus a single FoV. Auto-focus evaluation demonstrates a mean average maximum Laplacian value of 11.83 with tested images. The whole automation process is controlled by a smartphone device, which is responsible for acquiring images for further diagnosis via convolutional neural networks. The prototype is specially designed for resource-poor settings, where microscopy diagnosis is still a routine process. The coalescence between convolutional neural network predictive models and the automation of the movements of a conventional optical microscope confer the system a wide range of image-based diagnosis applications. The accessibility of the system could help improve diagnostics and provide new tools to laboratories worldwide.


Asunto(s)
Microscopía , Microscopía/métodos , Microscopía/instrumentación , Microscopía/economía , Humanos , Impresión Tridimensional/instrumentación , Programas Informáticos , Robótica/instrumentación , Teléfono Inteligente , Automatización , Imagenología Tridimensional/métodos
3.
Microsc Res Tech ; 87(7): 1521-1533, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38419399

RESUMEN

The outbreak of COVID-19 exposed the inadequacy of our technical tools for home health surveillance, and recent studies have shown the potential of smartphones as a universal optical microscopic imaging platform for such applications. However, most of them use laboratory-grade optomechanical components and transmitted illuminations to ensure focus tuning capability and imaging quality, which keeps the cost of the equipment high. Here, we propose an ultra-low-cost solution for smartphone microscopy. To realize focus tunability, we designed a seesaw-like structure capable of converting large displacements on one side into small displacements on the other (reduced to ∼9.1%), which leverages the intrinsic flexibility of 3D printing materials. We achieved a focus-tuning accuracy of ∼5 𝜇m, which is 40 times higher than the machining accuracy of the 3D-printed lens holder itself. For microscopic imaging, we used an off-the-shelf smartphone camera lens as the objective and the built-in flashlight as the illumination. To compensate for the resulting image quality degradation, we developed a learning-based image enhancement method. We used the CycleGAN architecture to establish the mapping from smartphone microscope images to benchtop microscope images without pairing. We verified the imaging performance on different biomedical samples. Except for the smartphone, we kept the full costs of the device under 4 USD. We think these efforts to lower the costs of smartphone microscopes will benefit their applications in various scenarios, such as point-of-care testing, on-site diagnosis, and home health surveillance. RESEARCH HIGHLIGHTS: We propose a solution for ultra-low-cost smartphone microscopy. Utilizing the flexibility of 3D-printed material, we can achieve focusing accuracy of ∼5 𝜇m. Such a low-cost device will benefit point-of-care diagnosis and home health surveillance.


Asunto(s)
COVID-19 , Microscopía , Teléfono Inteligente , Microscopía/métodos , Microscopía/instrumentación , Microscopía/economía , Humanos , COVID-19/diagnóstico , SARS-CoV-2 , Impresión Tridimensional/economía , Procesamiento de Imagen Asistido por Computador/métodos
5.
PLoS One ; 16(10): e0259056, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34695153

RESUMEN

BACKGROUND: Early diagnosis and treatment are one of the key strategies of tuberculosis control globally, and there are strong efforts in detecting and treating tuberculosis cases in Ethiopia. Smear microscopy examination has been a routine diagnostic test for pulmonary tuberculosis diagnosis in resource-constrained settings for decades. Recently, many countries, including Ethiopia, are scaling up the use of Gene Xpert without the evaluation of the cost and cost-effectiveness implications of this strategy. Therefore, this study evaluated the cost and cost-effectiveness of Gene Xpert (MTB/RIF) and smear microscopy tests to diagnosis tuberculosis patients in Ethiopia. METHODS: We compared the costs and cost-effectiveness of tuberculosis diagnosis using smear microscopy and Gene Xpert among 1332 patients per intervention in the Arsi zone. We applied combinations of top-down and bottom-up costing approaches. The costs were estimated from the health providers' perspective within one year (2017-2018). We employed "cases detected" as an effectiveness measure, and the incremental cost-effectiveness ratio was calculated by dividing the changes in cost and change in effectiveness. All costs and incremental cost-effectiveness ratio were reported in 2018 US$. RESULTS: The unit cost per test for Gene Xpert was $12.9 whereas it is $3.1 for AFB smear microscopy testing. The cost per TB case detected was $77.9 for Gene Xpert while it was $55.8 for the smear microscopy method. The cartridge kit cost accounted for 42% of the overall Gene Xpert's costs and the cost of the reagents and consumables accounted for 41.3% ($1.3) of the unit cost for the smear microscopy method. The ICER for the Gene Xpert strategy was $20.0 per tuberculosis case detected. CONCLUSION: Using Gene Xpert as a routine test instead of standard care (smear microscopy) can be potentially cost-effective. In the cost scenario analysis, the price of the cartridge, the number of tests performed per day, and the life span of the capital equipment were the drivers of the unit cost of the Gene Xpert method. Therefore, Gene Xpert can be a part of the routine TB diagnostic testing strategy in Ethiopia.


Asunto(s)
Microscopía/métodos , Mycobacterium tuberculosis/aislamiento & purificación , Esputo/microbiología , Tuberculosis Pulmonar/diagnóstico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Análisis Costo-Beneficio , Etiopía , Femenino , Humanos , Masculino , Microscopía/economía , Persona de Mediana Edad , Tuberculosis Pulmonar/economía , Adulto Joven
6.
Commun Biol ; 4(1): 439, 2021 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-33795833

RESUMEN

Cell-cell interfaces convey mechanical and chemical information in multicellular systems. Microscopy has revealed intricate structure of such interfaces, yet typically with limited resolution due to diffraction and unfavourable orthogonal orientation of the interface to the coverslip. We present a simple and robust way to align cell-cell interfaces in parallel to the coverslip by adhering the interacting cells to two opposing coverslips. We demonstrate high-quality diffraction-limited and super-resolution imaging of interfaces (immune-synapses) between fixed and live CD8+ T-cells and either antigen presenting cells or melanoma cells. Imaging methods include bright-field, confocal, STED, dSTORM, SOFI, SRRF and large-scale tiled images. The low background, lack of aberrations and enhanced spatial stability of our method relative to existing cell-trapping techniques allow use of these methods. We expect that the simplicity and wide-compatibility of our approach will allow its wide dissemination for super-resolving the intricate structure and molecular organization in a variety of cell-cell interfaces.


Asunto(s)
Linfocitos T CD8-positivos/citología , Microscopía/métodos , Análisis Costo-Beneficio , Microscopía/economía , Microscopía/instrumentación
7.
Diagn Pathol ; 16(1): 24, 2021 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-33731170

RESUMEN

BACKGROUND: The role of Artificial intelligence (AI) which is defined as the ability of computers to perform tasks that normally require human intelligence is constantly expanding. Medicine was slow to embrace AI. However, the role of AI in medicine is rapidly expanding and promises to revolutionize patient care in the coming years. In addition, it has the ability to democratize high level medical care and make it accessible to all parts of the world. MAIN TEXT: Among specialties of medicine, some like radiology were relatively quick to adopt AI whereas others especially pathology (and surgical pathology in particular) are only just beginning to utilize AI. AI promises to play a major role in accurate diagnosis, prognosis and treatment of cancers. In this paper, the general principles of AI are defined first followed by a detailed discussion of its current role in medicine. In the second half of this comprehensive review, the current and future role of AI in surgical pathology is discussed in detail including an account of the practical difficulties involved and the fear of pathologists of being replaced by computer algorithms. A number of recent studies which demonstrate the usefulness of AI in the practice of surgical pathology are highlighted. CONCLUSION: AI has the potential to transform the practice of surgical pathology by ensuring rapid and accurate results and enabling pathologists to focus on higher level diagnostic and consultative tasks such as integrating molecular, morphologic and clinical information to make accurate diagnosis in difficult cases, determine prognosis objectively and in this way contribute to personalized care.


Asunto(s)
Inteligencia Artificial , Interpretación de Imagen Asistida por Computador , Microscopía , Patólogos , Patología , Inteligencia Artificial/economía , Actitud del Personal de Salud , Actitud hacia los Computadores , Análisis Costo-Beneficio , Costos de la Atención en Salud , Conocimientos, Actitudes y Práctica en Salud , Humanos , Microscopía/economía , Patología/economía , Pautas de la Práctica en Medicina , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados
8.
Am J Otolaryngol ; 42(1): 102788, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33171411

RESUMEN

PURPOSE: The use of endoscopes in otologic procedures has been increasing worldwide. This study aimed to compare the efficacy of microscopic tympanoplasty (MT) and endoscopic tympanoplasty (ET) for tympanic membrane and middle ear surgery. MATERIALS AND METHODS: We retrospectively analyzed 81 patients who underwent MT (n = 44) and ET (n = 37) for chronic otitis media with tympanic membrane perforation performed by a single surgeon between January 2013 and September 2019. The hearing outcomes, graft success rate, complications, operation time and hospital stay, and cost-effectiveness were recorded and compared between groups. Hearing outcomes were determined by pure tone audiometry. Cost-effectiveness was determined by the operation cost and total cost. RESULTS: There was no significant difference between the MT and ET groups regarding demographic characteristics, with the exception of the male:female ratio. There was no significant difference in the pre- and postoperative air conduction, bone conduction thresholds, and air-bone gap values between the two groups, but a significant audiologic improvement was observed in both groups (p < 0.05). In terms of recurrence of tympanic membrane perforation, postoperative otorrhea, and discomfort symptoms, there was no significant difference between groups (p > 0.05). The operation time and hospital stay were shorter in the ET group than in the MT group (p < 0.05). There were no significant differences in operation cost between the two groups (p > 0.05), but the total cost was significantly lower in the ET group than the MT group (p < 0.05). CONCLUSION: ET is as safe and medically efficacious as conventional MT, shortens the operation time and hospital stay, and is cost-effective.


Asunto(s)
Oído Medio/cirugía , Endoscopía/métodos , Microscopía/métodos , Otitis Media/cirugía , Cirujanos , Perforación de la Membrana Timpánica/cirugía , Membrana Timpánica/cirugía , Timpanoplastia/métodos , Adulto , Enfermedad Crónica , Análisis Costo-Beneficio , Endoscopía/economía , Endoscopía/instrumentación , Femenino , Audición , Humanos , Tiempo de Internación/estadística & datos numéricos , Masculino , Microscopía/economía , Microscopía/instrumentación , Persona de Mediana Edad , Tempo Operativo , Otitis Media/economía , Otitis Media/fisiopatología , Resultado del Tratamiento , Perforación de la Membrana Timpánica/economía , Perforación de la Membrana Timpánica/fisiopatología , Timpanoplastia/economía , Timpanoplastia/instrumentación
9.
PLoS Med ; 17(12): e1003456, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33264288

RESUMEN

BACKGROUND: Active case finding (ACF) may be valuable in tuberculosis (TB) control, but questions remain about its optimum implementation in different settings. For example, smear microscopy misses up to half of TB cases, yet is cheap and detects the most infectious TB cases. What, then, is the incremental value of using more sensitive and specific, yet more costly, tests such as Xpert MTB/RIF in ACF in a high-burden setting? METHODS AND FINDINGS: We constructed a dynamic transmission model of TB, calibrated to be consistent with an urban slum population in India. We applied this model to compare the potential cost and impact of 2 hypothetical approaches following initial symptom screening: (i) 'moderate accuracy' testing employing a microscopy-like test (i.e., lower cost but also lower accuracy) for bacteriological confirmation and (ii) 'high accuracy' testing employing an Xpert-like test (higher cost but also higher accuracy, while also detecting rifampicin resistance). Results suggest that ACF using a moderate-accuracy test could in fact cost more overall than using a high-accuracy test. Under an illustrative budget of US$20 million in a slum population of 2 million, high-accuracy testing would avert 1.14 (95% credible interval 0.75-1.99, with p = 0.28) cases relative to each case averted by moderate-accuracy testing. Test specificity is a key driver: High-accuracy testing would be significantly more impactful at the 5% significance level, as long as the high-accuracy test has specificity at least 3 percentage points greater than the moderate-accuracy test. Additional factors promoting the impact of high-accuracy testing are that (i) its ability to detect rifampicin resistance can lead to long-term cost savings in second-line treatment and (ii) its higher sensitivity contributes to the overall cases averted by ACF. Amongst the limitations of this study, our cost model has a narrow focus on the commodity costs of testing and treatment; our estimates should not be taken as indicative of the overall cost of ACF. There remains uncertainty about the true specificity of tests such as smear and Xpert-like tests in ACF, relating to the accuracy of the reference standard under such conditions. CONCLUSIONS: Our results suggest that cheaper diagnostics do not necessarily translate to less costly ACF, as any savings from the test cost can be strongly outweighed by factors including false-positive TB treatment, reduced sensitivity, and foregone savings in second-line treatment. In resource-limited settings, it is therefore important to take all of these factors into account when designing cost-effective strategies for ACF.


Asunto(s)
Programas de Detección Diagnóstica/economía , Costos de la Atención en Salud , Pruebas de Sensibilidad Microbiana/economía , Microscopía/economía , Modelos Económicos , Técnicas de Diagnóstico Molecular/economía , Tuberculosis/diagnóstico , Tuberculosis/economía , Antituberculosos/economía , Antituberculosos/uso terapéutico , Análisis Costo-Beneficio , Costos de los Medicamentos , Farmacorresistencia Bacteriana , Humanos , India , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Factores de Tiempo , Tuberculosis/tratamiento farmacológico
10.
Malar J ; 19(1): 400, 2020 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-33172472

RESUMEN

BACKGROUND: Gestational malaria is associated with negative outcomes in maternal and gestational health; timely diagnosis is crucial to avoid complications. However, the limited infrastructure, equipment, test reagents, and trained staff make it difficult to use thick blood smear tests in rural areas, where rapid testing could be a viable alternative. The purpose of this study was to estimate the cost-effectiveness of rapid tests type III (Plasmodium falciparum/Plasmodium spp P.f/pan) versus microscopic tests for the diagnosis and treatment of gestational malaria in Colombia. METHODS: Cost-effectiveness analyses of gestational malaria diagnosis from an institutional perspective using a decision tree. Standard costing was performed for the identification, measurement and assessment phases, with data from Colombian tariff manuals. The data was collected from Health Situation Analysis, SIVIGILA and meta-analysis. Average and incremental cost-effectiveness ratio were estimated. The uncertainty was assessed through probabilistic sensitivity analysis. RESULTS: The cost of rapid diagnostic tests in 3,000 pregnant women with malaria was US$66,936 and 1,182 disability adjusted life years (DALYs) were estimated. The cost using thick blood smear tests was US$50,838 and 1,023 DALYs, for an incremental cost-effectiveness of US$ 101.2. The probabilistic sensitivity analysis of rapid diagnostic tests determined that they are highly cost-effective in 70% of the cases, even below the US$1,200 threshold; also, they showed an incremental net monetary benefit of $150,000 when payer's willingness is US$1,000. CONCLUSION: The use of rapid diagnostic tests for timely diagnosis and treatment of gestational malaria is a highly cost-effective strategy in Colombia, with uncertainty analyses supporting the robustness of this conclusion and the increased net monetary benefit that the health system would obtain. This strategy may help in preventing the negative effects on maternal health and the neonate at a low cost.


Asunto(s)
Análisis Costo-Beneficio/estadística & datos numéricos , Pruebas Diagnósticas de Rutina/economía , Malaria Falciparum/diagnóstico , Microscopía/economía , Complicaciones Parasitarias del Embarazo/diagnóstico , Adolescente , Adulto , Niño , Preescolar , Colombia , Pruebas Diagnósticas de Rutina/métodos , Femenino , Humanos , Microscopía/métodos , Plasmodium falciparum/aislamiento & purificación , Embarazo , Adulto Joven
11.
Appl Opt ; 59(10): 2969-2975, 2020 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-32400572

RESUMEN

In this work, the development and application of a cost-effective and robust digital lensless holographic microscopy (DLHM) system is presented. In the simple architecture of DLHM based on a point source and a digital camera, the production of the former is introduced by means of an engineered step-index optical fiber with a cone-shaped end tip. The conventional and regularly expensive point source in DLHM is produced by means of a high-numerical-aperture microscope objective and a metallic wavelength-sized pinhole. The proposed replacement renders to DLHM additional simplicity of building, in addition to mechanical stability and robustness, and further reduces the cost of the microscope. The simplified cost-effective DLHM architecture is utilized for imaging resolution test targets and samples of human blood and pond water, revealing competitive mechanical stability and trustable phase images of the imaged specimens.


Asunto(s)
Eritrocitos/clasificación , Holografía/instrumentación , Microscopía/instrumentación , Fibras Ópticas , Agua/química , Sangre , Análisis Costo-Beneficio , Diseño de Equipo , Holografía/economía , Humanos , Procesamiento de Imagen Asistido por Computador , Microscopía/economía
12.
World Neurosurg ; 138: e607-e619, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32171932

RESUMEN

BACKGROUND: The operative microscope, a commonly used tool in neurosurgery, is critical in many supratentorial tumor cases. However, use of operating microscope for supratentorial tumor varies by surgeon. OBJECTIVES: To assess complication rates, readmissions, and costs associated with operative microscope use in supratentorial resections. METHODS: A retrospective analysis was conducted using a national administrative database to identify patients with glioma or brain metastases who underwent supratentorial resection between 2007 and 2016. Univariate and multivariate analyses were used to assess 30-day complications, readmissions, and costs between patients who underwent resection with and without use of microscope. RESULTS: The cohort included 12,058 glioma patients and 5433 metastasis patients. Rates of microscope use varied by state from 19.0% to 68.6%. Microscope use was associated with $5228.90 in additional costs of index hospitalization among glioma patients (P <0.001), and $2824.00 among metastasis patients (P <0.001). Rates of intraoperative cerebral edema were lower among the microscope cohort than among the nonmicroscope cohort (P <0.027). Microscope use was associated with a slight reduction in 30-day rates of neurological complications (14.7% vs. 16.7%, P = 0.048), specifically in nonspecific cerebrovascular complications. There were no differences in rates of other complications, readmissions, or 30-day postoperative costs. CONCLUSIONS: Use of operative microscope for supratentorial resections varies by state and is associated with higher cost of surgery. Microscope use may be associated with lower rates of intraoperative cerebral edema and some cerebrovascular complications, but is not associated with significant differences in other complications, readmissions, or 30-day costs.


Asunto(s)
Microscopía/economía , Microcirugia/efectos adversos , Microcirugia/economía , Procedimientos Neuroquirúrgicos/efectos adversos , Procedimientos Neuroquirúrgicos/economía , Neoplasias Supratentoriales/economía , Neoplasias Supratentoriales/cirugía , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Trastornos Cerebrovasculares/economía , Trastornos Cerebrovasculares/etiología , Estudios de Cohortes , Costos y Análisis de Costo , Femenino , Glioma/economía , Glioma/cirugía , Humanos , Masculino , Microscopía/instrumentación , Persona de Mediana Edad , Metástasis de la Neoplasia , Readmisión del Paciente/economía , Readmisión del Paciente/estadística & datos numéricos , Complicaciones Posoperatorias/epidemiología , Estudios Retrospectivos , Adulto Joven
13.
Ann Glob Health ; 86(1): 16, 2020 02 13.
Artículo en Inglés | MEDLINE | ID: mdl-32090023

RESUMEN

Introduction: A clean and functional microscope is necessary for accurate diagnosis of infectious diseases. In tropical climates, high humidity levels and improper storage conditions allow for the accumulation of debris and fungus on the optical components of diagnostic equipment, such as microscopes. Objective: Our objective was to develop and implement a low-cost, sustainable, easy to manage, low-maintenance, passive humidity control chamber to both reduce debris accumulation and microbial growth onto the optical components of microscopes. Methods: Constructed from easily-sourced and locally available materials, the cost of each humidity control chamber is approximately $2.35 USD. Relative humidity levels were recorded every 30 minutes over a period of 10 weeks from two chambers deployed at the Belize Vector and Ecology Center and the University of Belize. Results: The humidity control chamber deployed at the University of Belize maintained internal relative humidity at an average of 35.3% (SD = 4.2%) over 10 weeks, while the average external relative humidity was 86.4% (SD = 12.4%). The humidity control chamber deployed at the Belize Vector and Ecology Center effectively maintained internal relative humidity to an average of 54.5% (SD = 9.4%) over 10 weeks, while the average external relative humidity was 86.9% (SD = 12.9%). Conclusions: Control of relative humidity is paramount for the sustainability of medical equipment in tropical climates. The humidity control chambers reduced relative humidity to levels that were not conducive for fungal growth while reducing microscope contamination from external sources. This will likely extend the service life of the microscopes while taking advantage of low-cost, locally sourced components.


Asunto(s)
Humedad/prevención & control , Higroscópicos , Microscopía/instrumentación , Clima Tropical , Belice , Costos y Análisis de Costo , Contaminación de Equipos/economía , Contaminación de Equipos/prevención & control , Equipos y Suministros , Hongos/crecimiento & desarrollo , Humanos , Humedad/efectos adversos , Higroscópicos/economía , Microscopía/economía , Dióxido de Silicio/economía
14.
J Biophotonics ; 12(9): e201800410, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31081258

RESUMEN

Manual hand counting of parasites in fecal samples requires costly components and substantial expertise, limiting its use in resource-constrained settings and encouraging overuse of prophylactic medication. To address this issue, a cost-effective, automated parasite diagnostic system that does not require special sample preparation or a trained user was developed. It is composed of an inexpensive (~US$350), portable, robotic microscope that can scan over the size of an entire McMaster chamber (100 mm2 ) and capture high-resolution (~1 µm lateral resolution) bright field images without need for user intervention. Fecal samples prepared using the McMaster flotation method were imaged, with the imaging region comprising the entire McMaster chamber. These images are then automatically segmented and analyzed using a trained convolution neural network (CNN) to robustly separate eggs from background debris. Simple postprocessing of the CNN output yields both egg species and egg counts. The system was validated by comparing accuracy with hand-counts by a trained operator, with excellent performance. As a further demonstration of utility, the system was used to conveniently quantify drug response over time in a single animal, showing residual disease due to Anthelmintic resistance after 2 weeks.


Asunto(s)
Aprendizaje Profundo , Heces/parasitología , Microscopía/métodos , Parasitemia/diagnóstico por imagen , Reconocimiento de Normas Patrones Automatizadas , Animales , Antihelmínticos/farmacología , Perros , Resistencia a Medicamentos , Eimeria , Cabras , Haplorrinos , Procesamiento de Imagen Asistido por Computador/métodos , Aprendizaje Automático , Microscopía/economía , Microscopía/veterinaria , Redes Neurales de la Computación , Parasitemia/economía , Parasitemia/veterinaria , Robótica , Ovinos , Manejo de Especímenes
15.
Lancet Glob Health ; 7(6): e798-e807, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31097281

RESUMEN

BACKGROUND: Rapid on-site diagnosis facilitates tuberculosis control. Performing Xpert MTB/RIF (Xpert) at point of care is feasible, even when performed by minimally trained health-care workers, and when compared with point-of-care smear microscopy, reduces time to diagnosis and pretreatment loss to follow-up. However, whether Xpert is cost-effective at point of care remains unclear. METHODS: We empirically collected cost (US$, 2014) and clinical outcome data from participants presenting to primary health-care facilities in four African countries (South Africa, Zambia, Zimbabwe, and Tanzania) during the TB-NEAT trial. Costs were determined using an bottom-up ingredients approach. Effectiveness measures from the trial included number of cases diagnosed, initiated on treatment, and completing treatment. The primary outcome was the incremental cost-effectiveness of point-of-care Xpert relative to smear microscopy. The study was performed from the perspective of the health-care provider. FINDINGS: Using data from 1502 patients, we calculated that the mean Xpert unit cost was lower when performed at a centralised laboratory (Lab Xpert) rather than at point of care ($23·00 [95% CI 22·12-23·88] vs $28·03 [26·19-29·87]). Per 1000 patients screened, and relative to smear microscopy, point-of-care Xpert cost an additional $35 529 (27 054-40 025) and was associated with an additional 24·3 treatment initiations ([-20·0 to 68·5]; $1464 per treatment), 63·4 same-day treatment initiations ([27·3-99·4]; $511 per same-day treatment), and 29·4 treatment completions ([-6·9 to 65·6]; $1211 per completion). Xpert costs were most sensitive to test volume, whereas incremental outcomes were most sensitive to the number of patients initiating and completing treatment. The probability of point-of-care Xpert being cost-effective was 90% at a willingness to pay of $3820 per treatment completion. INTERPRETATION: In southern Africa, although point-of-care Xpert unit cost is higher than Lab Xpert, it is likely to offer good value for money relative to smear microscopy. With the current availability of point-of-care nucleic acid amplification platforms (eg, Xpert Edge), these data inform much needed investment and resource allocation strategies in tuberculosis endemic settings. FUNDING: European Union European and Developing Countries Clinical Trials Partnership.


Asunto(s)
Técnicas de Amplificación de Ácido Nucleico/métodos , Pruebas en el Punto de Atención , Tuberculosis Pulmonar/diagnóstico , Análisis Costo-Beneficio , Costos de la Atención en Salud/estadística & datos numéricos , Humanos , Microscopía/economía , Microscopía/métodos , Técnicas de Amplificación de Ácido Nucleico/economía , Pruebas en el Punto de Atención/economía , Sudáfrica , Tanzanía , Tuberculosis Pulmonar/economía , Zambia , Zimbabwe
16.
PLoS One ; 14(3): e0208366, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30889174

RESUMEN

BACKGROUND: Detection of lymph node metastases is essential in breast cancer diagnostics and staging, affecting treatment and prognosis. Intraoperative microscopy analysis of sentinel lymph node frozen sections is standard for detection of axillary metastases but requires access to a pathologist for sample analysis. Remote analysis of digitized samples is an alternative solution but is limited by the requirement for high-end slide scanning equipment. OBJECTIVE: To determine whether the image quality achievable with a low-cost, miniature digital microscope scanner is sufficient for detection of metastases in breast cancer lymph node frozen sections. METHODS: Lymph node frozen sections from 79 breast cancer patients were digitized using a prototype miniature microscope scanner and a high-end slide scanner. Images were independently reviewed by two pathologists and results compared between devices with conventional light microscopy analysis as ground truth. RESULTS: Detection of metastases in the images acquired with the miniature scanner yielded an overall sensitivity of 91% and specificity of 99% and showed strong agreement when compared to light microscopy (k = 0.91). Strong agreement was also observed when results were compared to results from the high-end slide scanner (k = 0.94). A majority of discrepant cases were micrometastases and sections of which no anticytokeratin staining was available. CONCLUSION: Accuracy of detection of metastatic cells in breast cancer sentinel lymph node frozen sections by visual analysis of samples digitized using low-cost, point-of-care microscopy is comparable to analysis of digital samples scanned using a high-end, whole slide scanner. This technique could potentially provide a workflow for digital diagnostics in resource-limited settings, facilitate sample analysis at the point-of-care and reduce the need for trained experts on-site during surgical procedures.


Asunto(s)
Neoplasias de la Mama/patología , Ganglios Linfáticos/patología , Metástasis Linfática/diagnóstico por imagen , Microscopía/instrumentación , Femenino , Secciones por Congelación , Humanos , Metástasis Linfática/patología , Microscopía/economía , Miniaturización , Sistemas de Atención de Punto/economía , Estudios Retrospectivos , Sensibilidad y Especificidad
17.
Radiat Prot Dosimetry ; 186(1): 37-41, 2019 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-30806467

RESUMEN

Biological dosimetry is used to estimate individual absorbed radiation dose by quantifying an appropriate biological marker. The most popular gold-standard marker is the appearance of dicentric chromosomes in metaphase. The metaphase finder is a tool for biological dosimetry that finds metaphase cells on glass slides. The author and a software company have designed a new system and are now preparing to produce the system commercially. The metaphase finder consists of an automated microscope, a camera, and a computer. To enhance the accuracy of the system, an artificial intelligence (AI) with deep learning was tested. A total of 1709 images of the metaphase finder detected as 'metaphases' were read into a nine-layer artificial neural network to detect true metaphases. A total of 456 images were used for training, and the rest of the images were used for validation. The accuracy of AI was 0.89 for metaphases and 0.90 for non-metaphases.


Asunto(s)
Inteligencia Artificial , Aberraciones Cromosómicas , Análisis Citogenético/economía , Análisis Citogenético/métodos , Linfocitos/efectos de la radiación , Metafase/genética , Programas Informáticos , Humanos , Metafase/efectos de la radiación , Microscopía/economía , Microscopía/métodos , Dosis de Radiación
18.
Arch Pathol Lab Med ; 143(3): 299-304, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30525933

RESUMEN

CONTEXT.­: Our patients are now demanding value for their medical diagnoses and treatment in terms of optimal costs, quality, and outcomes. The financial justification for the introduction of new emerging technologies that may better meet these needs will depend on many factors, even if there is an established reimbursement code. In vivo and ex vivo microscopic technologies (IVM and EVM, respectively) will be used as examples of potentially transforming technologies. OBJECTIVE.­: To describe the components of a business plan that ensures all of the ramifications of introducing a new technology into pathology practice have been considered. As well as the financial justification, such a plan should include strategic vision and congruence, the advantages and drawbacks of introducing such technology, and how plans for marketing, implementation, and verification can be operationalized. DATA SOURCES.­: Unlike many pathologists, administrative directors in clinical laboratories already know the components of a financially sound business plan. In addition to the financial justifications, other considerations of such a plan include expense reductions, multiyear buildups in revenue generation, the replacement of other technologies, improved productivity and workflows, additional space, new capital, retrained personnel, and the impact on other departments. CONCLUSIONS.­: Pathologists will learn a business plan format to improve their confidence in making the sound financial justifications needed to consider the introduction of an emerging technology into pathology practice, even when there is initially no obvious revenue stream because formal reimbursement codes have not been established.


Asunto(s)
Microscopía/métodos , Patología/métodos , Patología/organización & administración , Comercio/economía , Comercio/métodos , Comercio/organización & administración , Humanos , Microscopía/economía , Patología/economía
19.
Acta Crystallogr F Struct Biol Commun ; 74(Pt 12): 797-802, 2018 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-30511674

RESUMEN

An inexpensive system for automated imaging of the contents of 12-, 24- and 96-well plates has been built. The xyz stage is constructed from parts from a light-duty computer numerical control wood-carving/engraving machine, and the Arduino-based board was wired so that it can trigger still images or movies though a microscope-mounted digital camera. The translation stage provides reproducible three-dimensional movement of the sample over a volume of 160 mm in x, 100 mm in y and 40 mm in z. A Python script generates the G-code command file that scans the plate and collects a series of z-stacked images of each sample. A second Python script automates the calculation of images with a digitally enhanced depth of field. The imaging system is currently being used to facilitate screening for protein crystals, but it could be used to automate the imaging of many other types of samples in multi-well plates.


Asunto(s)
Análisis Costo-Beneficio/métodos , Imagenología Tridimensional/economía , Microscopía/economía , Imagenología Tridimensional/instrumentación , Microscopía/instrumentación
20.
Biotechniques ; 65(6): 322-330, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30477327

RESUMEN

We describe a novel automated cell detection and counting software, QuickCount® (QC), designed for rapid quantification of cells. The Bland-Altman plot and intraclass correlation coefficient (ICC) analyses demonstrated strong agreement between cell counts from QC to manual counts (mean and SD: -3.3 ± 4.5; ICC = 0.95). QC has higher recall in comparison to ImageJauto, CellProfiler and CellC and the precision of QC, ImageJauto, CellProfiler and CellC are high and comparable. QC can precisely delineate and count single cells from images of different cell densities with precision and recall above 0.9. QC is unique as it is equipped with real-time preview while optimizing the parameters for accurate cell count and needs minimum hands-on time where hundreds of images can be analyzed automatically in a matter of milliseconds. In conclusion, QC offers a rapid, accurate and versatile solution for large-scale cell quantification and addresses the challenges often faced in cell biology research.


Asunto(s)
Recuento de Células/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Programas Informáticos , Animales , Recuento de Células/economía , Línea Celular , Línea Celular Tumoral , Humanos , Procesamiento de Imagen Asistido por Computador/economía , Ratones , Microscopía/economía , Microscopía/métodos , Factores de Tiempo , Flujo de Trabajo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA