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1.
Sci Rep ; 12(1): 2299, 2022 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-35145155

RESUMO

In endoscopic maxillary sinus surgery, the maxillary sinus is accessed through the nasal cavity which constitutes a narrow and tortuous pathway. However, surgeons still use rigid endoscopes and rigid, straight or pre-bent instruments for this procedure. Resection of the uncinate process and creation of a medial antrostomy is warranted to access the pathology inside the maxillary sinus and depending on the location of the pathology (lateral, inferior or anterior wall), additional resection of healthy tissue and/or functional structures like the lacrimal duct and/or inferior turbinate is necessary to gain optimal access. In order to avoid this additional resection, a functional single-handed, steerable endoscope for endoscopic maxillary sinus surgery has been designed and built. This endoscope is, to our knowledge, the most slender active steerable endoscope ever reported for maxillary sinus surgery. The performance of the endoscope was validated by two surgeons on a cadaver. An increased field of view was found in comparison to currently used endoscopes. As a direct consequence, a reduced need for resection of healthy tissue was confirmed.


Assuntos
Endoscópios , Seio Maxilar/cirurgia , Miniaturização/instrumentação , Procedimentos Cirúrgicos Nasais/instrumentação , Procedimentos Cirúrgicos Robóticos/instrumentação , Robótica/instrumentação , Humanos
2.
Opt Lett ; 45(22): 6238-6241, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-33186959

RESUMO

A miniature flexible photoacoustic endoscopy probe that provides high-resolution 3D images of vascular structures in the forward-viewing configuration is described. A planar Fabry-Perot ultrasound sensor with a -3dB bandwidth of 53 MHz located at the tip of the probe is interrogated via a flexible fiber bundle and a miniature optical relay system to realize an all-optical probe measuring 7.4 mm in outer diameter at the tip. This approach to photoacoustic endoscopy offers advantages over previous piezoelectric based distal-end scanning probes. These include a forward-viewing configuration in widefield photoacoustic tomography mode, finer spatial sampling (87 µm spatial sampling interval), and wider detection bandwidth (53 MHz) than has been achievable with conventional ultrasound detection technology and an all-optical passive imaging head for safe endoscopic use.


Assuntos
Endoscópios , Miniaturização/instrumentação , Fibras Ópticas , Técnicas Fotoacústicas/instrumentação , Cirurgia Assistida por Computador/instrumentação , Desenho de Equipamento , Fenômenos Mecânicos , Segurança , Tomografia
3.
Sci Rep ; 10(1): 13022, 2020 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-32747751

RESUMO

In order to overcome the challenges associated with a limited number of airway epithelial cells that can be obtained from clinical sampling and their restrained capacity to divide ex vivo, miniaturization of respiratory drug discovery assays is of pivotal importance. Thus, a 96-well microplate system was developed where primary human small airway epithelial (hSAE) cells were cultured at an air-liquid interface (ALI). After four weeks of ALI culture, a pseudostratified epithelium containing basal, club, goblet and ciliated cells was produced. The 96-well ALI cultures displayed a cellular composition, ciliary beating frequency, and intercellular tight junctions similar to 24-well conditions. A novel custom-made device for 96-parallelized transepithelial electric resistance (TEER) measurements, together with dextran permeability measurements, confirmed that the 96-well culture developed a tight barrier function during ALI differentiation. 96-well hSAE cultures were responsive to transforming growth factor ß1 (TGF-ß1) and tumor necrosis factor α (TNF-α) in a concentration dependent manner. Thus, the miniaturized cellular model system enables the recapitulation of a physiologically responsive, differentiated small airway epithelium, and a robotic integration provides a medium throughput approach towards pharmaceutical drug discovery, for instance, in respect of fibrotic distal airway/lung diseases.


Assuntos
Bronquíolos/citologia , Células Epiteliais/citologia , Miniaturização/instrumentação , Miniaturização/métodos , Modelos Biológicos , Ar , Automação , Biomarcadores/metabolismo , Células Cultivadas , Fibrose , Humanos , Mucosa Respiratória/citologia
4.
IEEE Trans Biomed Circuits Syst ; 14(4): 867-878, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32746346

RESUMO

Sensing implants that can be deployed by catheterization or by injection are preferable over implants requiring invasive surgery. However, present powering methods for active implants and present interrogation methods for passive implants require bulky parts within the implants that hinder the development of such minimally invasive devices. In this article, we propose a novel approach that potentially enables the development of passive sensing systems overcoming the limitations of previous implantable sensing systems in terms of miniaturization. In this approach implants are shaped as thread-like devices suitable for implantation by injection. Their basic structure consists of a thin elongated body with two electrodes at opposite ends and a simple and small circuit made up of a diode, a capacitor and a resistor. The interrogation method to obtain measurements from the implants consists in applying innocuous bursts of high frequency (≥1 MHz) alternating current that reach the implants by volume conduction and in capturing and processing the voltage signals that the implants produce after the bursts. As proof-of-concept, and for illustrating how to put in practice this novel approach, here we describe the development and characterization of a system for measuring the conductivity of tissues surrounding the implant. We also describe the implementation and the in vitro validation of a 0.95 mm-thick, flexible injectable implant made of off-the-shelf components. For conductivities ranging from about 0.2 to 0.8 S/m, when compared to a commercial conductivity meter, the accuracy of the implemented system was about ±10%.


Assuntos
Condutividade Elétrica , Miniaturização/instrumentação , Monitorização Fisiológica/instrumentação , Próteses e Implantes , Eletrônica Médica , Humanos , Perna (Membro)/fisiologia , Músculo Esquelético/fisiologia , Desenho de Prótese , Transdutores
5.
IEEE Trans Biomed Circuits Syst ; 14(4): 787-799, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32406844

RESUMO

An ASIC for a high frequency electrical impedance tomography (EIT) imaging system for prostate cancer screening is presented. The ASIC enables a small form-factor architecture, which ensures high signal-to-noise ratio (SNR) at MHz frequencies. The 4-channel ASIC was designed and fabricated in a standard CMOS 0.18- µm technology and integrates a novel current driver for current stimulus, instrumentation amplifier to interface with the tissue, VGA to provide variable gain and ADC with SPI interface for digitization. A prototype miniaturized EIT system was built and it was evaluated using a model transrectal imaging probe immersed into a tank filled with saline and a metal inclusion that demonstrated the open-domain problem of imaging prostate cancer lesion. The system maintained an SNR between 66 and 76 dB over the frequency range of 500 Hz to 1 MHz. Also, it produced reconstructed EIT images that depicted the presence of the small metal inclusion that modeled a prostate cancer imaging application.


Assuntos
Impedância Elétrica , Miniaturização/instrumentação , Próstata/diagnóstico por imagem , Tomografia , Desenho de Equipamento , Humanos , Masculino , Imagens de Fantasmas , Neoplasias da Próstata/diagnóstico por imagem , Razão Sinal-Ruído , Tomografia/instrumentação , Tomografia/métodos
6.
Electrophoresis ; 41(5-6): 319-327, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31850534

RESUMO

NMR shows strong analytical capability for obtaining molecular information on materials and is used in a variety of fields. Micro-NMR (µNMR) is mainly based on low-field NMR (LF-NMR), which makes NMR detection portable and inexpensive. Point-of-care testing (POCT) has gradually become an area of major concern, and scientists have made much progress in applying µNMR systems for POCT. To the best of our knowledge, this is the first review of the latest development in miniaturization of µNMR systems. Then, we discuss cutting-edge µNMR-based applications in POCT and the outlook for future developments.


Assuntos
Espectroscopia de Ressonância Magnética/instrumentação , Espectroscopia de Ressonância Magnética/métodos , Miniaturização/instrumentação , Testes Imediatos , Desenho de Equipamento , Humanos , Imageamento por Ressonância Magnética , Neoplasias/diagnóstico por imagem
7.
Theranostics ; 9(26): 8239-8252, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31754393

RESUMO

Rationale: Intraoperative visualization in small surgical cavities and hard-to-access areas are essential requirements for modern, minimally invasive surgeries and demand significant miniaturization. However, current optical imagers require multiple hard-to-miniaturize components including lenses, filters and optical fibers. These components restrict both the form-factor and maneuverability of these imagers, and imagers largely remain stand-alone devices with centimeter-scale dimensions. Methods: We have engineered INSITE (Immunotargeted Nanoparticle Single-Chip Imaging Technology), which integrates the unique optical properties of lanthanide-based alloyed upconverting nanoparticles (aUCNPs) with the time-resolved imaging of a 25-micron thin CMOS-based (complementary metal oxide semiconductor) imager. We have synthesized core/shell aUCNPs of different compositions and imaged their visible emission with INSITE under either NIR-I and NIR-II photoexcitation. We characterized aUCNP imaging with INSITE across both varying aUCNP composition and 980 nm and 1550 nm excitation wavelengths. To demonstrate clinical experimental validity, we also conducted an intratumoral injection into LNCaP prostate tumors in a male nude mouse that was subsequently excised and imaged with INSITE. Results: Under the low illumination fluences compatible with live animal imaging, we measure aUCNP radiative lifetimes of 600 µs - 1.3 ms, which provides strong signal for time-resolved INSITE imaging. Core/shell NaEr0.6Yb0.4F4 aUCNPs show the highest INSITE signal when illuminated at either 980 nm or 1550 nm, with signal from NIR-I excitation about an order of magnitude brighter than from NIR-II excitation. The 55 µm spatial resolution achievable with this approach is demonstrated through imaging of aUCNPs in PDMS (polydimethylsiloxane) micro-wells, showing resolution of micrometer-scale targets with single-pixel precision. INSITE imaging of intratumoral NaEr0.8Yb0.2F4 aUCNPs shows a signal-to-background ratio of 9, limited only by photodiode dark current and electronic noise. Conclusion: This work demonstrates INSITE imaging of aUCNPs in tumors, achieving an imaging platform that is thinned to just a 25 µm-thin, planar form-factor, with both NIR-I and NIR-II excitation. Based on a highly paralleled array structure INSITE is scalable, enabling direct coupling with a wide array of surgical and robotic tools for seamless integration with tissue actuation, resection or ablation.


Assuntos
Microscopia de Fluorescência , Miniaturização , Animais , Elementos da Série dos Lantanídeos/química , Masculino , Camundongos , Microscopia de Fluorescência/métodos , Microscopia de Fluorescência/tendências , Miniaturização/instrumentação , Miniaturização/métodos , Nanopartículas/química
8.
Opt Lett ; 44(7): 1868-1871, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30933168

RESUMO

In advanced biomedicine and microfluidics, there is a strong desire to sort and manipulate various cells and bacteria based on miniaturized microfluidic chips. Here, by integrating fiber tweezers into a T-type microfluidic channel, we report an optofluidic chip to selectively trap Escherichia coli in human blood solution based on different sizes and shapes. Furthermore, we simulate the trapping and pushing regions of other cells and bacteria, including rod-shaped bacteria, sphere-shaped bacteria, and cancer cells based on finite-difference analysis. With the advantages of controllability, low optical power, and compact construction, the strategy may be possibly applied in the fields of optical separation, cell transportation, and water quality analysis.


Assuntos
Separação Celular/instrumentação , Miniaturização/instrumentação , Fibras Ópticas , Pinças Ópticas , Animais , Desenho de Equipamento , Eritrócitos/microbiologia , Escherichia coli/citologia , Humanos
9.
Biomed Eng Online ; 18(1): 46, 2019 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-30999918

RESUMO

BACKGROUND: Vitreoretinal surgeries require precise, dexterous, and steady instruments for operation in delicate parts of the eye. Robotics has presented solutions for many vitreoretinal surgical problems, but, in a few operations, the available tools are still not dexterous enough to carry out procedures with minimum trauma to patients. Vitrectomy is one of those procedures and requires some dexterous instruments to replace straight ones for better navigation to affected sides inside the eyeball. METHOD: In this paper, we propose a new vein puncturing solution with a 4-DOF motion to increase the workspace inside the eye. A two-member concentric tube-based 25G needle is proposed whose shape is optimized. To operate the concentric tube needle, a novel and miniaturized actuation system is proposed that uses hollow shaft motors for the first time. The presented prototype of actuation system has a stroke of 100 mm in a small size of 148 × 25 × 65 mm (L × W × H), suitable for approaching distant positions inside the eyeball. RESULTS: Experimental results validate that the targeting accuracy of the needle is less than one millimeter and the needle tip can apply a force of 23.51 mN which is enough to perform puncturing. Furthermore, the proposed needle covers maximum workspace of around 128.5° inside the eyeball. For the actuation system, experiments show that it can produce repeatable motions with accuracy in submillimeter. CONCLUSION: The proposed needle system can navigate to the sites which are difficult to approach by currently available straight tools requiring reinsertions. Along with the miniaturized actuation system, this work is expected to improve the outcome of vitrectomy with safe and accurate navigation.


Assuntos
Miniaturização/instrumentação , Agulhas , Vitrectomia/instrumentação , Movimento (Física) , Robótica
10.
IEEE Trans Biomed Eng ; 66(3): 632-639, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-29993482

RESUMO

Clinical endoscopy and colonoscopy are commonly used to investigate and diagnose disorders in the upper gastrointestinal tract and colon, respectively. However, examination of the anatomically remote small bowel with conventional endoscopy is challenging. This and advances in miniaturization led to the development of video capsule endoscopy (VCE) to allow small bowel examination in a noninvasive manner. Available since 2001, current capsule endoscopes are limited to viewing the mucosal surface only due to their reliance on optical imaging. To overcome this limitation with submucosal imaging, work is under way to implement microultrasound (µUS) imaging in the same form as VCE devices. This paper describes two prototype capsules, termed Sonocap and Thermocap, which were developed respectively to assess the quality of µUS imaging and the maximum power consumption that can be tolerated for such a system. The capsules were tested in vivo in the oesophagus and small bowel of porcine models. Results are presented in the form of µUS B-scans as well as safe temperature readings observed up to 100 mW in both biological regions. These results demonstrate that acoustic coupling and µUS imaging can be achieved in vivo in the lumen of the bowel and the maximum power consumption that is possible for miniature µUS systems.


Assuntos
Cápsulas Endoscópicas , Endoscopia por Cápsula/instrumentação , Termometria/instrumentação , Ultrassonografia/instrumentação , Animais , Endoscopia por Cápsula/métodos , Colo/diagnóstico por imagem , Colo/fisiologia , Desenho de Equipamento , Feminino , Humanos , Miniaturização/instrumentação , Segurança do Paciente , Suínos , Termometria/métodos , Ultrassonografia/métodos
11.
Sci Transl Med ; 10(470)2018 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-30518611

RESUMO

Exposure to electromagnetic radiation can have a profound impact on human health. Ultraviolet (UV) radiation from the sun causes skin cancer. Blue light affects the body's circadian melatonin rhythm. At the same time, electromagnetic radiation in controlled quantities has beneficial use. UV light treats various inflammatory skin conditions, and blue light phototherapy is the standard of care for neonatal jaundice. Although quantitative measurements of exposure in these contexts are important, current systems have limited applicability outside of laboratories because of an unfavorable set of factors in bulk, weight, cost, and accuracy. We present optical metrology approaches, optoelectronic designs, and wireless modes of operation that serve as the basis for miniature, low-cost, and battery-free devices for precise dosimetry at multiple wavelengths. These platforms use a system on a chip with near-field communication functionality, a radio frequency antenna, photodiodes, supercapacitors, and a transistor to exploit a continuous accumulation mechanism for measurement. Experimental and computational studies of the individual components, the collective systems, and the performance parameters highlight the operating principles and design considerations. Evaluations on human participants monitored solar UV exposure during outdoor activities, captured instantaneous and cumulative exposure during blue light phototherapy in neonatal intensive care units, and tracked light illumination for seasonal affective disorder phototherapy. Versatile applications of this dosimetry platform provide means for consumers and medical providers to modulate light exposure across the electromagnetic spectrum in a way that can both reduce risks in the context of excessive exposure and optimize benefits in the context of phototherapy.


Assuntos
Fontes de Energia Elétrica , Miniaturização/instrumentação , Fototerapia , Dosímetros de Radiação , Exposição à Radiação , Monitoramento de Radiação/instrumentação , Luz Solar , Tecnologia sem Fio , Humanos , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Raios Ultravioleta
12.
J Biophotonics ; 11(11): e201800055, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30079507

RESUMO

The management of cancer in the periphery lung is in critical need of new strategies. Here, the development and test of a novel miniature Raman probe capable of navigating the peripheral lung architecture is reported. The probe was 1.35 mm in diameter, with a minimum bend radius of 13 mm and had a large light collection area for its size. Peripheral lung Raman spectra were successfully obtained from normal tissue and cancerous nodule using the probe coupled to a home-made rapid Raman spectroscopy system with a fast integration time of 1 second and a low excitation power of 15 mW. This is the first time in vivo Raman spectra from the periphery lung being reported. The collected spectra showed lipid, protein and deoxyhemoglobin signatures that might be useful for classifying pathology. Large scale clinical study is planned to confirm the utility of this new technology for improving periphery lung cancer detection. Left: Radial ultrasound image of a peripheral lung nodule: size given by crosshairs D1 and D2. Right: Truncated Raman spectra of a cancerous nodule, whole blood, and normal peripheral airway tissue. Spectra were shifted on intensity scale for clarity.


Assuntos
Detecção Precoce de Câncer/instrumentação , Neoplasias Pulmonares/diagnóstico , Miniaturização/instrumentação , Análise Espectral Raman/instrumentação , Desenho de Equipamento , Humanos
13.
J Breath Res ; 12(4): 046011, 2018 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-30008462

RESUMO

This work presents the performances of silicon micro-preconcentrators chips for breath sampling. The silicon chips were coupled to a handheld battery powered system for breath sampling and direct injection in a laboratory gas chromatography mass spectrometry system through thermal desorption (TD). Performances of micro-preconcentrators were first compared to commercial TD for benzene trapping. Similar chromatographic peaks after gas chromatographic separation were observed while the volume of sample needed was reduced by a factor of 5. Repeatability and day to day variability of the micro-preconcentrators were then studied for a 500 ppb synthetic model mixture injected three times a day four days in a row: 8% and 12% were measured respectively. Micro-preconcentrator to micro-preconcentrator variability was not significant compared to day to day variability. In addition, micro-preconcentrators were tested for breath samples collected in Tedlar® bags. Three analyses of the same breath sample displayed relative standard deviations values below 16% for eight of the ten most intense peaks. Finally, the performances of micro-preconcentrators for breath sampling on a single expiration were illustrated with the example of volatile tobacco markers tracking. The signals of three smoking markers in breath, benzene, 2,5-dimethylfuran, and toluene were studied. Concentrations of benzene and toluene were found to be 10 to 100 higher in the breath of smokers. 2,5-dimethylfuran was only found in the breath of smokers. The elimination kinetics of the markers were followed as well during 4 h: a fast decrease of the signal of the three markers in breath was observed 20 min after smoking in good agreement with what is described in the literature. Those results demonstrate the efficiency of silicon chips for breath sampling, compared to the state of the art techniques. Thanks to miniaturization and lower sample volumes needed, micro-preconcentrators could be in the future a key technology towards portable breath sampling and analysis.


Assuntos
Biomarcadores/análise , Testes Respiratórios/instrumentação , Miniaturização/instrumentação , Nicotiana/química , Silício/química , Compostos Orgânicos Voláteis/análise , Benzeno/análise , Furanos/análise , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Fumar , Tolueno/análise
14.
J Biomed Opt ; 23(7): 1-9, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29981222

RESUMO

Thulium fiber laser lithotripsy using smaller optical fibers may enable development of miniature ureteroscopes. Two ureteroscope distal tip prototypes were built and characterized. The first design was 4.5-French (Fr) [1.5-mm outer diameter (OD)], five channel tip, housing 200-µm inner diameter (ID) dedicated central channel for insertion of 100-µm core fibers and four surrounding channels, each with 1.5 Fr (510-µm ID) for instrumentation, irrigation, imaging, and illumination, respectively. The second design was 6.0-Fr (2.0-mm OD), three-dimensional printed tip with larger, hemispherical common working channel and separate detection port integrated with ring lighting. Standard instruments, including optical fibers, guidewires, and stone baskets, were inserted through working channels to demonstrate feasibility. Gravitational and manual pump-assisted saline irrigation rates were measured. Luminous intensity distribution curves (LIDCs) were modeled for both ring and conventional lighting designs. Imaging was conducted using 3000, 6000, and 10,000 pixel, miniature, flexible endoscopes with 0.4-, 0.6-, and 0.9-mm OD, to differentiate between urinary stones and ureter wall, for potential clinical application. The multichannel ureteroscope tip with 1.5-Fr working channel yielded a gravitational saline flow rate of 3.9 ± 0.2 mL / min compared to 31.3 ± 0.6 mL / min for standard (3.6 Fr) ureteroscope channel. Manual, pump-assisted irrigation increased flow rate to 32.5 ± 3.0 mL / min. The 6000 pixel, 0.6-mm OD, flexible endoscope provided a balance of clear differentiation between stones and ureter wall and sufficiently small OD. A ring lighting configuration provided more uniform illumination than conventional cross-lighting geometry as demonstrated by LIDCs. With further development, these miniature ureteroscope tip designs may be integrated into a fully functional ureteroscope to permit ureteral access with minimal trauma and improved patient safety and comfort.


Assuntos
Litotripsia a Laser/instrumentação , Miniaturização/instrumentação , Ureteroscópios , Ureteroscopia/instrumentação , Desenho de Equipamento , Humanos , Cálculos Renais/diagnóstico por imagem , Cálculos Renais/cirurgia , Cirurgia Assistida por Computador , Irrigação Terapêutica , Túlio
15.
J Biophotonics ; 11(10): e201800034, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29635741

RESUMO

Endoscopy is an essential clinical tool for the diagnosis of gastrointestinal (GI) tract cancer. A photoacoustic system that elegantly combines optical and ultrasound endoscopy advantages by providing high-sensitivity functional information and large imaging depth is a potentially powerful tool for GI tract imaging. Recently, several photoacoustic endoscopic imaging systems have been proposed and developed. However, the relatively large size and rigid length of the catheter make it difficult to translate them into wide clinical applications; while the existing system of a relatively small catheter, capable of in vivo animal imaging, is unable to acquire full (360°) field-of-view cross-section images. In this study, we developed a photoacoustic/ultrasonic dual-modality endoscopic system and a corresponding miniaturized, encapsulated imaging catheter, which provides a full 360° field-of-view. The diameter of the catheter is 2.5 mm, which is compatible with the 2.8-mm instrumental channel of a conventional clinical optical endoscope. Using this system, we demonstrate in vivo 3-dimensional endoscopic photoacoustic/ultrasonic imaging of the colorectum of a healthy Sprague Dawley rat, by depicting vasculature and morphology of the GI tract. The significantly improved imaging field of view, reduced catheter size, high-quality imaging results suggest that the developed photoacoustic/ultrasonic dual-modality endoscopy has a great potential to be translated into a broad range of clinical applications in gastroenterology.


Assuntos
Catéteres , Endoscopia/instrumentação , Miniaturização/instrumentação , Técnicas Fotoacústicas/instrumentação , Ultrassonografia/instrumentação , Animais , Desenho de Equipamento , Trato Gastrointestinal/diagnóstico por imagem , Ratos , Ratos Sprague-Dawley , Razão Sinal-Ruído
16.
Sci Rep ; 8(1): 431, 2018 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-29323197

RESUMO

Miniaturization of ureteroscopy materials is intended to decrease tissue damage. However, tissue hypoxia and the gross and microscopic effects on tissue have not been adequately assessed. We compared the gross and microscopic effects of micro-ureteroscopy (m-URS) and conventional ureteroscopy (URS) on the urinary tract. We employed 14 pigs of the Large White race. URS was performed in one of the ureters with an 8/9.8 F ureteroscope, while a 4.85 F m-URS sheath was used in the contralateral ureter. Gross assessment of ureteral wall damage and ureteral orifice damage was performed. For microscopic assessment hematoxylin-eosin staining and immunohistochemistry for detection of tissue hypoxia were conducted. Regarding the macroscopic assessment of ureteral damage, substantial and significant differences were recorded using URS (C = 0.8), but not with m-URS. Microscopic assessment after staining with hematoxylin-eosin revealed greater epithelial desquamation in the URS group (p < 0.05). Pimonidazole staining revealed greater hypoxia in the epithelial cells than in the remainder of the ureteral layers. We conclude that m-URS causes less damage to the ureteral orifice than URS. Histopathological findings show m-URS reduces ureteral epithelial damage compared with conventional ureteroscopy. Both URS and m-URS cause cellular hypoxia.


Assuntos
Miniaturização/instrumentação , Ureter/lesões , Ureteroscopia/efeitos adversos , Animais , Hipóxia Celular , Feminino , Microscopia , Suínos , Ureter/diagnóstico por imagem
17.
IEEE Trans Biomed Eng ; 65(1): 140-148, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28436843

RESUMO

OBJECTIVE: this work presents the design, fabrication, and testing of a miniaturized and integrated ultrasound endoscope for use as an in situ digestive diagnostic device to facilitate real-time ultrasound guidance of intervention treatments. METHODS: we designed an optimal structure to integrate an auto-focus 5-megapixel camera module with an 8-MHz, 64-element curvilinear ultrasonic array in one miniaturized package. A novel three-axis auto-focusing voice coil motor (VCM) was designed and manufactured for the camera module to move the lens position for auto-focusing and to adjust the lens tilt. RESULTS: the results showed that the array had a center frequency of 8.09 MHz and a -6-dB fractional bandwidth of 83%. At the center frequency, the two-way insertion loss was 40.6 dB. Endoscopic ultrasound imaging demonstrated satisfactory performance for imaging an anthropomorphic phantom of the esophagus. By slightly adjusting the tilt angle of the optical axis of the lens, the optical image captured by the auto-focusing lens obtained improved definition regardless of changes in the view angle of the camera with respect to the objects being captured. CONCLUSION: the integrated convex ultrasound endoscope, possessing minimal size, improved optical imaging definition, and good ultrasound imaging performance, can become a useful tool in digestive tract imaging. SIGNIFICANCE: the miniaturized and integrated convex ultrasound endoscope can facilitate real-time ultrasound intervention guidance, reducing risks associated with the operation.


Assuntos
Endoscópios Gastrointestinais , Endoscopia Gastrointestinal/instrumentação , Miniaturização/instrumentação , Ultrassonografia/instrumentação , Desenho de Equipamento , Esôfago/diagnóstico por imagem , Humanos , Imagens de Fantasmas
18.
Phys Med ; 42: 116-126, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29173904

RESUMO

Radiotherapy with protons and carbon ions enables to deliver dose distributions of high conformation to the target. Treatment with helium ions has been suggested due to their physical and biological advantages. A reliable benchmarking of the employed physics models with experimental data is required for treatment planning. However, experimental data for helium interactions is limited, in part due to the complexity and large size of conventional experimental setups. We present a novel method for the investigation of helium interactions with matter using miniaturized instrumentation based on highly integrated pixel detectors. The versatile setup consisted of a monitoring detector in front of the PMMA phantom of varying thickness and a detector stack for investigation of outgoing particles. The ion type downstream from the phantom was determined by high-resolution pattern recognition analysis of the single particle signals in the pixelated detectors. The fractions of helium and hydrogen ions behind the used targets were determined. As expected for the stable helium nucleus, only a minor decrease of the primary ion fluence along the target depth was found. E.g. the detected fraction of hydrogen ions on axis of a 220MeV/u 4He beam was below 6% behind 24.5cm of PMMA. Monte-Carlo simulations using Geant4 reproduce the experimental data on helium attenuation and yield of helium fragments qualitatively, but significant deviations were found for some combinations of target thickness and beam energy. The presented method is promising to contribute to the reduction of the uncertainty of treatment planning for helium ion radiotherapy.


Assuntos
Radioterapia com Íons Pesados/instrumentação , Radioterapia com Íons Pesados/métodos , Hélio/uso terapêutico , Íons/uso terapêutico , Miniaturização , Simulação por Computador , Desenho de Equipamento , Hidrogênio , Miniaturização/instrumentação , Método de Monte Carlo , Imagens de Fantasmas , Polimetil Metacrilato , Radiometria/instrumentação , Planejamento da Radioterapia Assistida por Computador/instrumentação , Planejamento da Radioterapia Assistida por Computador/métodos
19.
Chirurg ; 88(8): 647-655, 2017 Aug.
Artigo em Alemão | MEDLINE | ID: mdl-28484787

RESUMO

Minilaparoscopy was introduced already 20 years ago. In spite of reduced diameter, technical performance of modern trocars and instruments has improved substantially. While carrying out a minilaparoscopic procedure, the required position of the trocars and the surgical strategy remain the same. The most important step towards minilaparoscopy is reduction of the diameter of the laparoscopes from 10 to 5 mm. The 5 mm laparoscopes show high resolution and transport enough energy to properly illuminate the surgical field. Minilaparoscopic procedures help to improve cosmetic results and reduce postoperative pain, but postoperative complication rates are not affected. Use of one 5 mm trocar causes higher tissue tension than two 3 mm trocars and an additionally placed 3 mm trocar will not increase the complication rate. Therefore, a reduced risk of trocar hernia formation may be expected when a minilaparoscopic approach is used. Efficiency has been proven for minilaparoscopic cholecystectomy, appendectomy, and hernioplasty (TAPP/TEP) whereas overall available evidence across the literature remains poor. Further miniaturization is linked directly to video editing: physical limitations in classic optic systems have already been reached; therefore, reduction of optical chip systems could be a possible alternative.


Assuntos
Laparoscopia/instrumentação , Miniaturização/instrumentação , Procedimentos Cirúrgicos Minimamente Invasivos/instrumentação , Óptica e Fotônica , Instrumentos Cirúrgicos , Apendicectomia/instrumentação , Colecistectomia Laparoscópica/instrumentação , Desenho de Equipamento , Estética , Herniorrafia/instrumentação , Humanos , Dor Pós-Operatória/etiologia , Dor Pós-Operatória/prevenção & controle , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle
20.
Electrophoresis ; 38(17): 2168-2174, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28556952

RESUMO

A miniaturized chemical sensor is here described for the analysis of environmental pollutants (VOC: volatile organic chemicals). It is used for remote detection of formaldehyde (FA) fumes in the atmosphere, and is based on the redox reaction between FA and silver nitrate. The sensor is worn as a bracelet and the data acquired are transferred via a Bluetooth channel to a smartphone. A dedicated software transforms the signal from a grey to a color scale. The signal response has been assessed over low (20 to 120 ppb) as well as higher (1-15 ppm range) levels. The sensor has been applied to monitor potential FA fumes of some artwork in the Summer Palace in Beijing and the modifications induced by FA treatment on a precious Stradivarius violin. The performance of this novel sensor is compared with a commercial apparatus widely adopted, namely the Honeywell MultiRAE Lite wireless portable multi-gas monitor (pumped model).


Assuntos
Monitoramento Ambiental/instrumentação , Monitoramento Ambiental/métodos , Formaldeído/análise , Miniaturização/instrumentação , Smartphone , Sensibilidade e Especificidade , Compostos Orgânicos Voláteis/análise
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