Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.149
Filtrar
Mais filtros











Intervalo de ano de publicação
1.
PLoS One ; 19(5): e0302476, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38709742

RESUMO

BACKGROUND: The Incentive Spirometer (IS) increases lung volume and improves gas exchange by visually stimulating patients to take slow, deep breaths. It prevents respiratory complications and treats postoperative atelectasis in patients undergoing abdominal, thoracic, and neurosurgical procedures. Its effectiveness has been validated in studies that support improved lung capacities and volumes in individuals with respiratory complications, postoperative thoracic surgery, upper abdominal surgery, and bariatric surgery. The modified Pachón incentive spirometer (MPIS) is a cost-effective alternative to branded IS. It is crucial to validate whether the MPIS distributes ventilation as effectively as commercial devices do. Ventilation distribution will be measured using electrical impedance tomography. OBJECTIVE: The aim is to compare the distribution of pulmonary ventilation between the MPIS and another commercial IS in healthy adults using electrical impedance tomography. METHODS: A crossover clinical trial is proposed to evaluate the measurement of pulmonary ventilation distribution using EIT in a sample of healthy adults. All participants will use a commercial flow IS and the MPIS, with the order of assignment randomized. This research will use electrical impedance tomography to validate the operation of the MPIS. CONCLUSIONS: This study protocol will compare two incentive spirometers' impact on pulmonary ventilation, potentially endorsing the adoption of a cost-effective device to enhance accessibility for targeted populations. TRIAL REGISTRATION: The study was registered in ClinicalTrials.gov (NTC05532748).


Assuntos
Impedância Elétrica , Ventilação Pulmonar , Espirometria , Tomografia , Humanos , Adulto , Espirometria/métodos , Espirometria/instrumentação , Tomografia/métodos , Ventilação Pulmonar/fisiologia , Masculino , Feminino , Voluntários Saudáveis , Estudos Cross-Over , Pulmão/fisiologia , Pessoa de Meia-Idade , Adulto Jovem
2.
Sci Rep ; 14(1): 10597, 2024 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-38719924

RESUMO

Parotid lumps are a heterogeneous group of mainly benign but also malignant tumors. Preoperative imaging does not allow a differentiation between tumor types. Multispectral optoacoustic tomography (MSOT) may improve the preoperative diagnostics. In this first prospective pilot trial the ability of MSOT to discriminate between the two most frequent benign parotid tumors, pleomorphic adenoma (PA) and Warthin tumor (WT) as well as to normal parotid tissue was explored. Six wavelengths (700, 730, 760, 800, 850, 900 nm) and the parameters deoxygenated (HbR), oxygenated (HbO2), total hemoglobin (HbT), and saturation of hemoglobin (sO2) were analyzed. Ten patients with PA and fourteen with WT were included (12/12 female/male; median age: 51 years). For PA, the mean values for all measured wave lengths as well as for the hemoglobin parameters were different for the tumors compared to the healthy parotid (all p < 0.05). The mean MSOT parameters were all significantly higher (all p < 0.05) in the WT compared to healthy parotid gland except for HbT and sO2. Comparing both tumors directly, the mean values of MSOT parameters were not different between PA and WT (all p > 0.05). Differences were seen for the maximal MSOT parameters. The maximal tumor values for 900 nm, HbR, HbT, and sO2 were lower in PA than in WT (all p < 0.05). This preliminary MSOT parotid tumor imaging study showed clear differences for PA or WT compared to healthy parotid tissue. Some MSOT characteristics of PA and WT were different but needed to be explored in larger studies.


Assuntos
Neoplasias Parotídeas , Técnicas Fotoacústicas , Humanos , Feminino , Neoplasias Parotídeas/diagnóstico por imagem , Neoplasias Parotídeas/patologia , Pessoa de Meia-Idade , Masculino , Projetos Piloto , Estudos Prospectivos , Técnicas Fotoacústicas/métodos , Adulto , Idoso , Hemoglobinas/análise , Hemoglobinas/metabolismo , Adenolinfoma/diagnóstico por imagem , Adenolinfoma/patologia , Adenoma Pleomorfo/diagnóstico por imagem , Adenoma Pleomorfo/patologia , Tomografia/métodos , Glândula Parótida/diagnóstico por imagem , Glândula Parótida/patologia
3.
Physiol Meas ; 45(5)2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38599226

RESUMO

Objective.Making up one of the largest shares of diagnosed cancers worldwide, skin cancer is also one of the most treatable. However, this is contingent upon early diagnosis and correct skin cancer-type differentiation. Currently, methods for early detection that are accurate, rapid, and non-invasive are limited. However, literature demonstrating the impedance differences between benign and malignant skin cancers, as well as between different types of skin cancer, show that methods based on impedance differentiation may be promising.Approach.In this work, we propose a novel approach to rapid and non-invasive skin cancer diagnosis that leverages the technologies of difference-based electrical impedance tomography (EIT) and graphene electronic tattoos (GETs).Main results.We demonstrate the feasibility of this first-of-its-kind system using both computational numerical and experimental skin phantom models. We considered variations in skin cancer lesion impedance, size, shape, and position relative to the electrodes and evaluated the impact of using individual and multi-electrode GET (mGET) arrays. The results demonstrate that this approach has the potential to differentiate based on lesion impedance, size, and position, but additional techniques are needed to determine shape.Significance.In this way, the system proposed in this work, which combines both EIT and GET technology, exhibits potential as an entirely non-invasive and rapid approach to skin cancer diagnosis.


Assuntos
Impedância Elétrica , Grafite , Imagens de Fantasmas , Neoplasias Cutâneas , Tomografia , Grafite/química , Tomografia/instrumentação , Tomografia/métodos , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/diagnóstico por imagem , Humanos , Eletrodos , Tatuagem
4.
Sci Rep ; 14(1): 9669, 2024 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-38671072

RESUMO

Serious blunt chest trauma usually induces hemothorax, pneumothorax, and rib fractures. More studies have claimed that early video-assisted thoracoscopic surgery with surgical stabilization of rib fractures (SSRF) results in a good prognosis in patients with major trauma. This study aimed to verify the outcomes in patients with chest trauma whether SSRF was performed. Consecutive patients who were treated in a medical center in Taiwan, for traumatic events between January 2015 and June 2020, were retrospectively reviewed. This study focused on patients with major trauma and thoracic injuries, and they were divided into groups based on whether they received SSRF. We used electrical impedance tomography (EIT) to evaluate the change of ventilation conditions. Different scores used for the evaluation of trauma severity were also compared in this study. Among the 8396 patients who were included, 1529 (18.21%) had major trauma with injury severity score > 16 and were admitted to the intensive care unit initially. A total of 596 patients with chest trauma were admitted, of whom 519 (87%) survived. Younger age and a lower trauma score (including injury severity scale, new injury severity score, trauma and injury severity score, and revised trauma score) account for better survival rates. Moreover, 74 patients received SSRF. They had a shorter intensive care unit (ICU) stay (5.24, p = 0.045) and better performance in electrical impedance tomography (23.46, p < 0.001). In patients with major thoracic injury, older age and higher injury survival scale account for higher mortality rate. Effective surgical stabilization of rib fractures shortened the ICU stay and helped achieve better performance in EIT. Thoracoscope-assisted rib fixation is suggested in severe trauma cases.


Assuntos
Impedância Elétrica , Fraturas das Costelas , Traumatismos Torácicos , Humanos , Fraturas das Costelas/cirurgia , Fraturas das Costelas/diagnóstico por imagem , Feminino , Masculino , Pessoa de Meia-Idade , Traumatismos Torácicos/cirurgia , Traumatismos Torácicos/diagnóstico por imagem , Adulto , Estudos Retrospectivos , Idoso , Resultado do Tratamento , Cirurgia Torácica Vídeoassistida/métodos , Escala de Gravidade do Ferimento , Tomografia/métodos
5.
Respirar (Ciudad Autón. B. Aires) ; 16(1): 31-43, Marzo 2024.
Artigo em Espanhol | LILACS, UNISALUD, BINACIS | ID: biblio-1551189

RESUMO

Introducción: El cáncer de pulmón (CP) es una enfermedad con gran impacto a nivel mundial en el número de muertes y en costos en salud. La alta incidencia y mortalidad de esta enfermedad asociada al diagnóstico tardío, y la mejoría del pronóstico ante una detección temprana, determinan que sea una patología pasible de beneficiarse mediante detección temprana. La tomografía de baja dosis de radiación (TCBD) demostró ser un método que se pue- de realizar periódicamente a un grupo de personas con alto riesgo de desarrollar CP y así reducir la mortalidad por esta enfermedad. Sin embargo, este beneficio es tal cuan- do se encuentra desarrollado bajo un programa organizado y con participación multi- disciplinaria especializada en cáncer de pulmón. Métodos: Se plantea determinar lineamientos básicos para el desarrollo de la detección temprana de cáncer de pulmón en América Latina para que pueda ser realizada en forma uniforme, con el menor riesgo y el máximo beneficio esperado. Se analizaron las principales publicaciones referidas a este tema, contemplando la diversidad de atención y acceso de América Latina. Resultado: Se desarrollan requerimientos mínimos para la implementación de un pro- grama. Discusión: El número de programas en la región es escaso y depende más de esfuerzos individuales que de políticas generales de salud. Consideramos que estos lineamien- tos pueden servir de apoyo para el desarrollo de más programas en la región y de for- ma más homogénea.


Introduction: Lung cancer (LC) is a disease with a great impact worldwide in the number of deaths and health costs. The high incidence and mortality of this disease associated with late diagnosis and the improved prognosis with early detection determine that it is a pathology that can benefit from early detection. Low radiation dose tomography (LDCT) demonstrated a method that can be performed periodically to a group of people at high risk of developing CP and thus reduce mortality from this disease. However, this benefit is such when it is developed under an organized program with multidisciplinary participation specialized in lung cancer. Methods: It is proposed to determine basic guidelines for the development of early de- tection of lung cancer in Latin America so that it can be carried out uniformly, with the lowest risk and the maximum expected benefit. The main publications referring to this topic were analyzed, considering the diversity of care and access in Latin America. Result: Minimum requirements are developed for the implementation of a program. Discussion: The number of programs in the region is small and depends more on individual efforts than on general health policies. We consider that these guidelines can serve as support for the development of more programs in the region and in a more ho- mogeneous way.


Assuntos
Humanos , Planos e Programas de Saúde , Detecção Precoce de Câncer , Neoplasias Pulmonares/diagnóstico , Equipe de Assistência ao Paciente/organização & administração , Serviços Preventivos de Saúde/organização & administração , Tomografia/métodos , Incidência , Mortalidade , Educação Profissionalizante , Política de Saúde , América Latina
6.
J Biophotonics ; 17(4): e202300457, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38221652

RESUMO

Optoacoustic imaging enables the measurement of tissue oxygen saturation (sO2) and blood perfusion while being utilized for detecting tumor microenvironments. Our aim was to employ multispectral optoacoustic tomography (MSOT) to assess immediate-early changes of hemoglobin level and sO2 within breast tumors during diverse treatments. Mouse breast cancer models were allocated into four groups: control, everolimus (EVE), paclitaxel (PTX), and photodynamic therapy (PDT). Hemoglobin was quantified daily, as well as sO2 and blood perfusion were verified by immunohistochemical (IHC) staining. MSOT showed a temporal window of enhanced oxygenation and improved perfusion in EVE and PTX groups, while sO2 consistently remained below baseline in PDT. The same results were obtained for the IHC. Therefore, MSOT can monitor tumor hypoxia and indirectly reflect blood perfusion in a non-invasive and non-labeled way, which has the potential to monitor breast cancer progression early and enable individualized treatment in clinical practice.


Assuntos
Neoplasias , Técnicas Fotoacústicas , Animais , Camundongos , Tomografia/métodos , Monitorização Fisiológica , Hipóxia Tumoral , Paclitaxel , Hemoglobinas , Técnicas Fotoacústicas/métodos , Microambiente Tumoral
7.
Nat Commun ; 15(1): 147, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38167247

RESUMO

Optical tomography has emerged as a non-invasive imaging method, providing three-dimensional insights into subcellular structures and thereby enabling a deeper understanding of cellular functions, interactions, and processes. Conventional optical tomography methods are constrained by a limited illumination scanning range, leading to anisotropic resolution and incomplete imaging of cellular structures. To overcome this problem, we employ a compact multi-core fibre-optic cell rotator system that facilitates precise optical manipulation of cells within a microfluidic chip, achieving full-angle projection tomography with isotropic resolution. Moreover, we demonstrate an AI-driven tomographic reconstruction workflow, which can be a paradigm shift from conventional computational methods, often demanding manual processing, to a fully autonomous process. The performance of the proposed cell rotation tomography approach is validated through the three-dimensional reconstruction of cell phantoms and HL60 human cancer cells. The versatility of this learning-based tomographic reconstruction workflow paves the way for its broad application across diverse tomographic imaging modalities, including but not limited to flow cytometry tomography and acoustic rotation tomography. Therefore, this AI-driven approach can propel advancements in cell biology, aiding in the inception of pioneering therapeutics, and augmenting early-stage cancer diagnostics.


Assuntos
Tomografia Óptica , Tomografia , Humanos , Rotação , Tomografia/métodos , Tomografia Óptica/métodos , Tecnologia de Fibra Óptica , Imagens de Fantasmas , Inteligência Artificial , Algoritmos , Processamento de Imagem Assistida por Computador/métodos
8.
Physiol Meas ; 45(1)2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38176102

RESUMO

Objective.The aim of the present study was to evaluate the influence of one-sided pulmonary nodule and tumour on ventilation distribution pre- and post- partial lung resection.Approach.A total of 40 consecutive patients scheduled for laparoscopic lung parenchymal resection were included. Ventilation distribution was measured with electrical impedance tomography (EIT) in supine and surgery lateral positions 72 h before surgery (T1) and 48 h after extubation (T2). Left lung to global ventilation ratio (Fl), the global inhomogeneity index (GI), standard deviation of regional ventilation delay (RVDSD) and pendelluft amplitude (Apendelluft) were calculated to assess the spatial and temporal ventilation distribution.Main results.After surgery (T2), ventilation at the operated chest sides generally deteriorated compared to T1 as expected. For right-side resection, the differences were significant at both supine and left lateral positions (p< 0.001). The change of RVDSDwas in general more heterogeneous. For left-side resection, RVDSDwas worse at T2 compared to T1 at left lateral position (p= 0.002). The other EIT-based parameters showed no significant differences between the two time points. No significant differences were observed between supine and lateral positions for the same time points respectively.Significance.In the present study, we found that the surgery side influenced the ventilation distribution. When the resection was performed on the right lung, the postoperative ipsilateral ventilation was reduced and the right lung ratio fell significantly. When the resection was on the left lung, the ventilation delay was significantly increased.


Assuntos
Laparoscopia , Tomografia , Humanos , Tomografia/métodos , Respiração , Pulmão/cirurgia , Tomografia Computadorizada por Raios X , Impedância Elétrica , Ventilação Pulmonar
9.
IEEE Trans Biomed Eng ; 71(1): 97-105, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37440379

RESUMO

OBJECTIVE: This study explores the feasibility of coupling Electrical Impedance Tomography (EIT) to a standard-of-care laparoscopic surgical stapler, stapler+EIT, with the long-term goal of enabling intraoperative tissue differentiation for tumor margin detection. METHODS: Two custom printed-circuit-board-based electrode arrays with 60 and 8 electrodes, respectively, matching the stapler geometry, served as the jaws of an electrode-integrated surrogate stapler+EIT device. The device was evaluated through a series of simulations and bench-top imaging experiments of agar-gel phantoms and bovine tissue samples to evaluate the technique and determine optimal imaging parameters. RESULTS: Electrodes localized to only one jaw (the 60-electrode side) of the stapler outperformed a dual-jaw distribution of electrodes. Using this one-sided electrode array, reconstructions achieved an Area-Under-the-Curve (AUC) ≥ 0.94 for inclusions with conductivity contrasts of ≥30% for any size considered on measured agar-gel tests, and an AUC of 0.80 for bovine tissue samples. CONCLUSION: A stapler+EIT algorithm has been tuned and evaluated on challenging phantom tests and demonstrated to produce accurate reconstructions. SIGNIFICANCE: This work is an important step in the development of a surgical stapler+EIT technique for margin assessment.


Assuntos
Grampeadores Cirúrgicos , Tomografia , Animais , Bovinos , Tomografia/métodos , Impedância Elétrica , Ágar , Tomografia Computadorizada por Raios X , Eletrodos
10.
IEEE Trans Biomed Eng ; 71(4): 1370-1377, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37995176

RESUMO

In this article we investigate the possibility of using needles, which the interventional radiologist inserts near a deep-seated tumor during an electroporation-based therapy, to characterize the electrical conductivity of patient's tissues. Specifically, we propose to exploit voltage/current measurements and imaging that are performed prior to the application of electroporation pulses. The approach is partly based on the concepts of electrical impedance tomography; however, imaging is used to build a specific geometric model and compensate for the lack of information resulting from the small number of electrodes available. 3D canonical and clinical examples, where a few electrodes surround a tumor, demonstrate the feasibility of this method: solving the inverse problem to estimate tissues conductivity converges in a few iterations. For a given error on the measurement, it is also possible to calculate the error on the estimated conductivities. The uncertainty error with clinical data is at best 5% for one of the tissues identified, due to the limitations of the clinical device used. Various improvements to clinical devices are discussed to make the conductivity estimation more accurate but also to extract more information.


Assuntos
Neoplasias , Tomografia , Humanos , Impedância Elétrica , Tomografia/métodos , Fluxo de Trabalho , Condutividade Elétrica , Eletroporação/métodos , Neoplasias/terapia
11.
Magn Reson Med ; 91(3): 1190-1199, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37876351

RESUMO

PURPOSE: Several reconstruction methods for MR-based electrical properties tomography (EPT) have been developed. However, the lack of common data makes it difficult to objectively compare their performances. This is, however, a necessary precursor for standardizing and introducing this technique in the clinical setting. To enable objective comparison of the performances of reconstruction methods and provide common data for their training and testing, we created ADEPT, a database of simulated data for brain MR-EPT reconstructions. METHODS: ADEPT is a database containing in silico data for brain EPT reconstructions. This database was created from 25 different brain models, with and without tumors. Rigid geometric augmentations were applied, and different electrical properties were assigned to white matter, gray matter, CSF, and tumors to generate 120 different brain models. These models were used as input for finite-difference time-domain simulations in Sim4Life, used to compute the electromagnetic fields needed for MR-EPT reconstructions. RESULTS: Electromagnetic fields from 84 healthy and 36 tumor brain models were simulated. The simulated fields relevant for MR-EPT reconstructions (transmit and receive RF fields and transceive phase) and their ground-truth electrical properties are made publicly available through ADEPT. Additionally, nonattainable fields such as the total magnetic field and the electric field are available upon request. CONCLUSION: ADEPT will serve as reference database for objective comparisons of reconstruction methods and will be a first step toward standardization of MR-EPT reconstructions. Furthermore, it provides a large amount of data that can be exploited to train data-driven methods. It can be accessed from  https://doi.org/10.34894/V0HBJ8.


Assuntos
Processamento de Imagem Assistida por Computador , Neoplasias , Humanos , Condutividade Elétrica , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Encéfalo/diagnóstico por imagem , Tomografia/métodos , Imagens de Fantasmas , Algoritmos
12.
Artigo em Inglês | MEDLINE | ID: mdl-38082917

RESUMO

Recent development of affordable, portable and self-administrable electrical impedance tomography (EIT) system demonstrated the feasibility of using standalone EIT and subject's anthropometrics to predict the gold standard spirometry indicators for lung-function assessment. Compared to spirometry, the system showed the advantage of providing spatial mapping of the spirometry indicators. Nevertheless, the previous study was limited to healthy subjects. Here, we recruited (N=88): 47 lung disease patients and 41 healthy controls to perform simultaneous EIT and spirometry measurements to validate the capabilities of the system. Lung disease patients include 13 interstitial lung disease (ILD), 10 asthma, 8 chronic obstructive pulmonary disease (COPD), 8 bronchiectasis, and 8 with other diseases including left pneumonectomy, lung cancer, lung tumor, lymphangioleiomyomatosis, motor neuron disease, heart failure and bronchiolitis obliterans syndrome. The results showed significant correlation of the predicted global spirometry indicators (p<0.0001) and significant distinguishability between most disease groups and healthy subjects demonstrating the capability of the EIT system in diagnostic screening. Furthermore, the regional mapping of the spirometry indicators is evaluated and shown to be distinct for each disease group, providing an additional dimension for medical professionals to diagnose and monitor lung disease patients.Clinical Relevance- This establishes the significance of EIT-based global and regional indicators for assessing lung function on lung disease patients.


Assuntos
Neoplasias Pulmonares , Doença Pulmonar Obstrutiva Crônica , Humanos , Impedância Elétrica , Tomografia/métodos , Tomografia Computadorizada por Raios X , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Pulmão/diagnóstico por imagem
13.
Artigo em Inglês | MEDLINE | ID: mdl-38083170

RESUMO

Fluorescence molecular tomography (FMT) is a highly sensitive and noninvasive optical imaging technique which has been widely applied to disease diagnosis and drug discovery. However, FMT reconstruction is a highly ill-posed problem. In this work, L0-norm regularization is employed to construct the mathematical model of the inverse problem of FMT. And an adaptive sparsity orthogonal least square with a neighbor strategy (ASOLS-NS) is proposed to solve this model. This algorithm can provide an adaptive sparsity and can establish the candidate sets by a novel neighbor expansion strategy for the orthogonal least square (OLS) algorithm. Numerical simulation experiments have shown that the ASOLS-NS improves the reconstruction of images, especially for the double targets reconstruction.Clinical relevance- The purpose of this work is to improve the reconstruction results of FMT. Current experiments are focused on simulation experiments, and the proposed algorithm will be applied to the clinical tumor detection in the future.


Assuntos
Processamento de Imagem Assistida por Computador , Tomografia , Processamento de Imagem Assistida por Computador/métodos , Análise dos Mínimos Quadrados , Tomografia/métodos , Imagem Óptica/métodos , Simulação por Computador
14.
Artigo em Inglês | MEDLINE | ID: mdl-38082583

RESUMO

Electrical properties (EPs) are expected as biomarkers for early cancer detection. Magnetic resonance electrical properties tomography (MREPT) is a technique to non-invasively estimate the EPs of tissues from MRI measurements. While noise sensitivity and artifact problems of MREPT are being solved progressively through recent efforts, the loss of tissue contrast emerges as an obstacle to the clinical applications of MREPT. To solve the problem, we propose a reconstruction error compensation neural network scheme (REC-NN) for a typical analytic MREPT method, Stab-EPT. Two NN structures: one with only ResNet blocks, and the other hybridizing ResNet blocks with an encoder-decoder structure. Results of experiments with digital brain phantoms show that, compared with Stab-EPT, and conventional NN based reconstruction, REC-NN improves both reconstruction accuracy and tissue contrast. It is found that, the encoder-decoder structure could improve the compensation accuracy of EPs in homogeneous region but showed worse reconstruction than only ResNet structure for tumorous tissues unseen in the training samples. Future research is required to address overcompensation problems, optimization of NN structure and application to clinical data.


Assuntos
Algoritmos , Imageamento por Ressonância Magnética , Impedância Elétrica , Imageamento por Ressonância Magnética/métodos , Tomografia/métodos , Espectroscopia de Ressonância Magnética , Redes Neurais de Computação
15.
Eur J Anaesthesiol ; 40(11): 805-816, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37789753

RESUMO

BACKGROUND: A protective intra-operative lung ventilation strategy has been widely recommended for laparoscopic surgery. However, there is no consensus regarding the optimal level of positive end-expiratory pressure (PEEP) and its effects during pneumoperitoneum. Electrical impedance tomography (EIT) has recently been introduced as a bedside tool to monitor lung ventilation in real-time. OBJECTIVE: We hypothesised that individually titrated EIT-PEEP adjusted to the surgical intervention would improve respiratory mechanics during and after surgery. DESIGN: Randomised controlled trial. SETTING: First Medical Centre of Chinese PLA General Hospital, Beijing. PATIENTS: Seventy-five patients undergoing robotic-assisted laparoscopic hepatobiliary and pancreatic surgery under general anaesthesia. INTERVENTIONS: Patients were randomly assigned 2 : 1 to individualised EIT-titrated PEEP (PEEPEIT; n = 50) or traditional PEEP 5 cmH2O (PEEP5 cmH2O; n = 25). The PEEPEIT group received individually titrated EIT-PEEP during pneumoperitoneum. The PEEP5 cmH2O group received PEEP of 5 cmH2O during pneumoperitoneum. MAIN OUTCOME MEASURES: The primary outcome was respiratory system compliance during laparoscopic surgery. Secondary outcomes were individualised PEEP levels, oxygenation, respiratory and haemodynamic status, and occurrence of postoperative pulmonary complications (PPCs) within 7 days. RESULTS: Compared with PEEP5 cmH2O, patients who received PEEPEIT had higher respiratory system compliance (mean values during surgery of 44.3 ±â€Š11.3 vs. 31.9 ±â€Š6.6, ml cmH2O-1; P < 0.001), lower driving pressure (11.5 ±â€Š2.1 vs. 14.0 ±â€Š2.4 cmH2O; P < 0.001), better oxygenation (mean PaO2/FiO2 427.5 ±â€Š28.6 vs. 366.8 ±â€Š36.4; P = 0.003), and less postoperative atelectasis (19.4 ±â€Š1.6 vs. 46.3 ±â€Š14.8 g of lung tissue mass; P = 0.003). Haemodynamic values did not differ significantly between the groups. No adverse effects were observed during surgery. CONCLUSION: Individualised PEEP by EIT may improve intra-operative pulmonary mechanics and oxygenation without impairing haemodynamic stability, and decrease postoperative atelectasis. TRIAL REGISTRATION: Chinese Clinical Trial Registry (www.chictr.org.cn) identifier: ChiCTR2100045166.


Assuntos
Pneumoperitônio , Atelectasia Pulmonar , Humanos , Impedância Elétrica , Pneumoperitônio/etiologia , Pulmão/diagnóstico por imagem , Respiração com Pressão Positiva/métodos , Atelectasia Pulmonar/etiologia , Atelectasia Pulmonar/prevenção & controle , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Tomografia/métodos
16.
Sensors (Basel) ; 23(20)2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37896737

RESUMO

Laparoscopic surgery with capnoperitoneum brings many advantages to patients, but also emphasizes the negative impact of anesthesia and mechanical ventilation on the lungs. Even though many studies use electrical impedance tomography (EIT) for lung monitoring during these surgeries, it is not clear what the best position of the electrode belt on the patient's thorax is, considering the cranial shift of the diaphragm. We monitored 16 patients undergoing a laparoscopic surgery with capnoperitoneum using EIT with two independent electrode belts at different tomographic levels: in the standard position of the 4th-6th intercostal space, as recommended by the manufacturer, and in a more cranial position at the level of the axilla. Functional residual capacity (FRC) was measured, and a recruitment maneuver was performed at the end of the procedure by raising the positive end-expiratory pressure (PEEP) by 5 cmH2O. The results based on the spectral analysis of the EIT signal show that the ventilation-related impedance changes are not detectable by the belt in the standard position. In general, the cranial belt position might be more suitable for the lung monitoring during the capnoperitoneum since the ventilation signal remains dominant in the obtained impedance waveform. FRC was significantly decreased by the capnoperitoneum and remained lower also after desufflation.


Assuntos
Laparoscopia , Tomografia Computadorizada por Raios X , Humanos , Impedância Elétrica , Tomografia/métodos , Eletrodos
17.
Am J Ophthalmol ; 256: 146-155, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37567431

RESUMO

PURPOSE: To investigate the hereditability of corneal tomographic and biomechanical parameters in keratoconus (KC). DESIGN: Prospective cohort study. METHODS: This study was conducted at Qingdao Eye Hospital of Shandong First Medical University in Qingdao, China. Forty-four patients with KC and their biological parents (n = 88) were recruited as the study group. The control group consisted of 84 healthy adults with matched age and gender. Both eyes of each participant underwent clinical examinations, and 1 eye was selected for statistical analysis. Exclusion criteria were as follows: individuals with glaucoma, ocular surgery, systemic diseases known to affect the eyes, or poor cooperation during examination. Subjects were asked to discontinue soft contact lens (CL) wear for 2 weeks and rigid gas permeable CL wear for 4 weeks before ocular examination. All participants underwent a comprehensive assessment including Pentacam Scheimpflug tomography, Corvis ST, visual acuity, refraction examination, axial length, and slitlamp examination for both eyes. Individuals presenting with KC manifestations in at least 1 eye were classified as having KC. A total of 9 Pentacam indices including keratometry in the flat/steep meridian (K1/K2), maximal keratometry (Kmax), thinnest point pachymetry (TP), and maximum/average Ambrósio relational thickness (ARTmax/ARTave), anterior and posterior surfaces elevation of the cornea (Ef/Eb) and total deviation value (Final D), and 21 biomechanical indices were collected. Associations of these factors with KC were evaluated using multiple comparison and binary logistics regression analyses. RESULTS: Two parents (2.27%) from 2 different families were diagnosed with KC. Parents of patients with KC had thinner corneas with altered corneal biomechanical parameters compared with healthy controls (P < .05). The combined tomographic and biomechanical index demonstrated the highest discriminatory power (area under the receiver operating characteristic curve 0.785) and strong specificity (84.5%). Parental corneal tomographic and biomechanical index, Corvis biomechanical index, and TP were identified as the major influential factors for KC in their offspring by logistic regression analysis, with a 73.3% accuracy in identifying offspring with KC. CONCLUSIONS: Parental corneal tomographic and biomechanical properties of patients with KC suggest a possible predisposition to KC. A combination of tomography and corneal biomechanics can be helpful in predicting the incidence rate of KC in the offspring of patients with subclinical KC.


Assuntos
Ceratocone , Adulto , Humanos , Ceratocone/diagnóstico , Estudos Prospectivos , Topografia da Córnea/métodos , Paquimetria Corneana/métodos , Córnea , Curva ROC , Tomografia/métodos , Pais , Fenômenos Biomecânicos
18.
J Biomed Opt ; 28(6): 066005, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37396685

RESUMO

Significance: Fluorescence molecular tomography (FMT) is a promising imaging modality, which has played a key role in disease progression and treatment response. However, the quality of FMT reconstruction is limited by the strong scattering and inadequate surface measurements, which makes it a highly ill-posed problem. Improving the quality of FMT reconstruction is crucial to meet the actual clinical application requirements. Aim: We propose an algorithm, neighbor-based adaptive sparsity orthogonal least square (NASOLS), to improve the quality of FMT reconstruction. Approach: The proposed NASOLS does not require sparsity prior information and is designed to efficiently establish a support set using a neighbor expansion strategy based on the orthogonal least squares algorithm. The performance of the algorithm was tested through numerical simulations, physical phantom experiments, and small animal experiments. Results: The results of the experiments demonstrated that the NASOLS significantly improves the reconstruction of images according to indicators, especially for double-target reconstruction. Conclusion: NASOLS can recover the fluorescence target with a good location error according to simulation experiments, phantom experiments and small mice experiments. This method is suitable for sparsity target reconstruction, and it would be applied to early detection of tumors.


Assuntos
Processamento de Imagem Assistida por Computador , Tomografia , Animais , Camundongos , Processamento de Imagem Assistida por Computador/métodos , Fluorescência , Análise dos Mínimos Quadrados , Tomografia/métodos , Simulação por Computador , Imagens de Fantasmas , Algoritmos
20.
Adv Exp Med Biol ; 1403: 171-200, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37495919

RESUMO

Ultrasound tomography (USCT) is a promising imaging modality, mainly aiming at early diagnosis of breast cancer. It provides three-dimensional, reproducible images of higher quality than conventional ultrasound methods and additionally offers quantitative information on tissue properties. This chapter provides an introduction to the background and history of USCT, followed by an overview of image reconstruction algorithms and system design. It concludes with a discussion of current and future applications as well as limitations and their potential solutions.


Assuntos
Neoplasias da Mama , Tomografia Computadorizada por Raios X , Humanos , Feminino , Ultrassonografia , Processamento de Imagem Assistida por Computador/métodos , Neoplasias da Mama/diagnóstico por imagem , Imageamento Tridimensional/métodos , Algoritmos , Imagens de Fantasmas , Tomografia/métodos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA