8 research outputs found
Thinking Twice: Clinical-Inspired Thyroid Ultrasound Lesion Detection Based on Feature Feedback
Accurate detection of thyroid lesions is a critical aspect of computer-aided
diagnosis. However, most existing detection methods perform only one feature
extraction process and then fuse multi-scale features, which can be affected by
noise and blurred features in ultrasound images. In this study, we propose a
novel detection network based on a feature feedback mechanism inspired by
clinical diagnosis. The mechanism involves first roughly observing the overall
picture and then focusing on the details of interest. It comprises two parts: a
feedback feature selection module and a feature feedback pyramid. The feedback
feature selection module efficiently selects the features extracted in the
first phase in both space and channel dimensions to generate high semantic
prior knowledge, which is similar to coarse observation. The feature feedback
pyramid then uses this high semantic prior knowledge to enhance feature
extraction in the second phase and adaptively fuses the two features, similar
to fine observation. Additionally, since radiologists often focus on the shape
and size of lesions for diagnosis, we propose an adaptive detection head
strategy to aggregate multi-scale features. Our proposed method achieves an AP
of 70.3% and AP50 of 99.0% on the thyroid ultrasound dataset and meets the
real-time requirement. The code is available at
https://github.com/HIT-wanglingtao/Thinking-Twice.Comment: 20 pages, 11 figures, released code for
https://github.com/HIT-wanglingtao/Thinking-Twic
CMU-Net: A Strong ConvMixer-based Medical Ultrasound Image Segmentation Network
U-Net and its extensions have achieved great success in medical image
segmentation. However, due to the inherent local characteristics of ordinary
convolution operations, U-Net encoder cannot effectively extract global context
information. In addition, simple skip connections cannot capture salient
features. In this work, we propose a fully convolutional segmentation network
(CMU-Net) which incorporates hybrid convolutions and multi-scale attention
gate. The ConvMixer module extracts global context information by mixing
features at distant spatial locations. Moreover, the multi-scale attention gate
emphasizes valuable features and achieves efficient skip connections. We
evaluate the proposed method using both breast ultrasound datasets and a
thyroid ultrasound image dataset; and CMU-Net achieves average Intersection
over Union (IoU) values of 73.27% and 84.75%, and F1 scores of 84.81% and
91.71%. The code is available at https://github.com/FengheTan9/CMU-Net.Comment: This work has been submitted to the IEEE for possible publication.
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CMUNeXt: An Efficient Medical Image Segmentation Network based on Large Kernel and Skip Fusion
The U-shaped architecture has emerged as a crucial paradigm in the design of
medical image segmentation networks. However, due to the inherent local
limitations of convolution, a fully convolutional segmentation network with
U-shaped architecture struggles to effectively extract global context
information, which is vital for the precise localization of lesions. While
hybrid architectures combining CNNs and Transformers can address these issues,
their application in real medical scenarios is limited due to the computational
resource constraints imposed by the environment and edge devices. In addition,
the convolutional inductive bias in lightweight networks adeptly fits the
scarce medical data, which is lacking in the Transformer based network. In
order to extract global context information while taking advantage of the
inductive bias, we propose CMUNeXt, an efficient fully convolutional
lightweight medical image segmentation network, which enables fast and accurate
auxiliary diagnosis in real scene scenarios. CMUNeXt leverages large kernel and
inverted bottleneck design to thoroughly mix distant spatial and location
information, efficiently extracting global context information. We also
introduce the Skip-Fusion block, designed to enable smooth skip-connections and
ensure ample feature fusion. Experimental results on multiple medical image
datasets demonstrate that CMUNeXt outperforms existing heavyweight and
lightweight medical image segmentation networks in terms of segmentation
performance, while offering a faster inference speed, lighter weights, and a
reduced computational cost. The code is available at
https://github.com/FengheTan9/CMUNeXt.Comment: 8 pages, 3 figure
A Method of Two-Stage Pressure Control Based on Multistage Orifices
The interaction of pressure and flow in a hydraulic system with multiple working conditions, multiple actuators, and large flow limits action adjustment and control. Through a pilot pressure control circuit, hydraulically operated valves can adjust pressure or direction more effectively. A recent study proposed a two-stage pressure control method based on multistage orifices and solenoid valves. The requirements of the number and diameter ratio of short orifices in the series to realize the two-stage pressure control were theoretically analyzed. Scheme design and experiment were carried out. The influence of structures of complex flow channel and solenoid valve on the higher or lower pilot control pressure was considered in the experiment. The method was experimentally verified and successfully applied in a turbine electrohydraulic control system with lower maintenance costs, making the system more reliable in the case of electrical failure. Research results provide insight into pilot pressure control in fluid systems using multistage orifices to achieve either higher or lower pressure. In addition, it has important guiding significance for the design of valves or engineering systems based on pilot hydraulic pressure
Multi-Level Global Context Cross Consistency Model for Semi-Supervised Ultrasound Image Segmentation with Diffusion Model
Medical image segmentation is a critical step in computer-aided diagnosis,
and convolutional neural networks are popular segmentation networks nowadays.
However, the inherent local operation characteristics make it difficult to
focus on the global contextual information of lesions with different positions,
shapes, and sizes. Semi-supervised learning can be used to learn from both
labeled and unlabeled samples, alleviating the burden of manual labeling.
However, obtaining a large number of unlabeled images in medical scenarios
remains challenging. To address these issues, we propose a Multi-level Global
Context Cross-consistency (MGCC) framework that uses images generated by a
Latent Diffusion Model (LDM) as unlabeled images for semi-supervised learning.
The framework involves of two stages. In the first stage, a LDM is used to
generate synthetic medical images, which reduces the workload of data
annotation and addresses privacy concerns associated with collecting medical
data. In the second stage, varying levels of global context noise perturbation
are added to the input of the auxiliary decoder, and output consistency is
maintained between decoders to improve the representation ability. Experiments
conducted on open-source breast ultrasound and private thyroid ultrasound
datasets demonstrate the effectiveness of our framework in bridging the
probability distribution and the semantic representation of the medical image.
Our approach enables the effective transfer of probability distribution
knowledge to the segmentation network, resulting in improved segmentation
accuracy. The code is available at
https://github.com/FengheTan9/Multi-Level-Global-Context-Cross-Consistency.Comment: 10 pages, 8 figures, Released code for
https://github.com/FengheTan9/Multi-Level-Global-Context-Cross-Consistenc
Adsorption of Tetracycline with Reduced Graphene Oxide Decorated with MnFe2O4 Nanoparticles
Abstract Nanomaterials were widely used as efficient adsorbents for environmental remediation of tetracycline pollution. However, the separation of the adsorbents posed the challenge to their practical applications. In this study, we grew magnetic MnFe2O4 nanoparticles on the reduced graphene oxide (rGO) to form MnFe2O4/rGO nanocomposite with a one-step method. When used as the absorbent of Tetracycline, it exhibited an adsorption capacity of 41 mg/g. The adsorption kinetics and isotherm were fitted well with the pseudo-second order model and Freundlich model, respectively. The MnFe2O4/rGO nanocomposite could be easily extracted from the solution with the external magnetic field and regenerated with acid washing