143 results about "Small blood vessel" patented technology

A surgical clip applier for use in closing wounds under the microscope in small blood vessels modifies a well-known clip applier system to make more steady and reliable the application of very small clips during surgery on a scale of vessel size of 2 mm in external diameter and smaller. The known device is modified internally so as to be capable of receiving a flexible remote actuation device which can be a cable release such as used for a camera shutter, or which can be a flexible hydraulic or pneumatic line as a force-transmitting device. Thus, the surgeon can hold the clip applier very steadily at the site desired without contracting any intrinsic muscles while the cable release is depressed by another person, or with the surgeon's other hand, or with a foot pedal.

A device arranged to sustain and / or provide at least partial patency of a small blood vessel exhibiting an occlusion, the device constituted of a tubular body expandable from a first small diameter state for manipulation to, and through, the occlusion of the small blood vessel and a second large diameter state, the inner dimensions of the second large diameter state being no more than 50% of the diameter of the small blood vessel at the occlusion location, the device presenting a conduit for blood flow through the occlusion when in the large diameter state. In one embodiment the small blood vessel is an intracranial blood vessel.

Embolectomy catheters, rapid exchange microcatheters, systems and methods for removing clots or other obstructive matter (e.g., thrombus, thromboemboli, embolic fragments of atherosclerotic plaque, foreign objects, etc.) from blood vessels. This invention is particularly useable for percutaneous removal of thromboemboli or other obstructive matter from small blood vessels of the brain, during an evolving stroke or period of cerebral ischemia. In some embodiments, the embolectomy catheters of this invention are advanceable with or over a guidewire which has been pre-inserted through or around the clot. Also, in some embodiments, the embolectomy catheters include clot removal devices which are deployable from the catheter after the catheter has been advanced at least partially through the clot. The clot removal device may included a deployable wire nest that is designed to prevent a blood clot from passing therethrough. The delivery catheter may include telescoping inner and outer tubes, with the clot removal device being radially constrained by the outer tube. Retraction of the outer tube removes the constraint on the clot removal device and permits it to expand to its deployed configuration. An infusion guidewire is particularly useful in conjunction with the embolectomy catheter, and permits infusion of medicaments or visualization fluids distal to the clot.

An ultrasound catheter adapted for accessing small vessels in the distal anatomy is disclosed. The ultrasound catheter comprises an elongate tubular body formed with a delivery lumen. The flexibility and dimensions of the tubular body allow access to the distal anatomy by advancement over the guidewire. An ultrasound radiating member is provided along the distal end portion of the tubular body for emitting ultrasound energy at a treatment site. A drug solution may also be delivered through the delivery lumen and out an exit port to the treatment site.

Aspects of the present invention relate to NF-HEV nuclear factor genes and polypeptides. Other aspects related to the use of NF-HEV nuclear factor genes and polypeptides. Other aspects related to the use of NF-HEV nuclear factor polynucleotides and polypeptides expressed in endothelial cells from chronically inflamed tissues, particularly in high endothelial venules endothelial cells (HEVECs) and endothelial cells from HEV-like vessels and small blood vessels, in connection with rheumatoid arthritis and Crohn's disease. Aspects of the invention also relates to drug screening assays for identifying compounds capable of modulating NF-HEV activity, wherein such compounds can be used in inhibiting or preventing chronic inflammation.

The invention provides a retinal fundus vessel segmentation method based on a deep multi-scale attention convolutional neural network. An internationally disclosed retinal fundus vessel data set DRIVEis adopted to perform validity verification: firstly, dividing the retinal fundus vessel data set DRIVE into a training set and a test set, and adjusting the picture size to 512*512 pixels; then, enabling the training set to be subjected to four random preprocessing links to achieve a data enhancement effect; designing a model structure of the deep multi-scale attention convolutional neural network, and inputting the processed training set into the model for training; and finally, inputting the test set into the trained network, and testing the model performance. The main innovation point ofthe method is that a double attention module is designed, so that the whole model pays more attention to segmentation of small blood vessels; and a multi-scale feature fusion module is designed, so that the global feature extraction capability of the whole model on the segmented image is stronger. The segmentation accuracy of the model on a DRIVE data set is 96.87%, the sensitivity is 79.45%, thespecificity is 98.57, and the method is superior to classical UNet and an existing most advanced segmentation method.

The invention discloses a device for crushing and taking-off thrombus. The device comprises a conducting wire, a crossing mesh, a strainer, a draught device, a multi ball bag conduct pipe and a casing conduct pipe. A plurality of ball bags are arranged in series on the soft part of the far end of the multi ball bag conduct pipe; the crossing mesh and the strainer are sleeved through compression on the far end of the ball bag conduct pipe and covered on the ball bags, the ball bags are filled, the crossing mesh and the strainer are pulled off, and the thrombus or other emboli in the small blood vessel is crushed and taken off.

The present invention is directed to a dual diameter guide wire that is steerable inside the lumen of a patient, and provides greater ability to access small areas such as the interior of a needle, or the interior of a patient's lumen such as small blood vessels, thereby improving access to a patient's body during interventional procedures. The present invention is also directed to medical devices for interventional applications, methods of accessing the interior of a lumen of a patient's body and methods of preparing a guide wire.

The invention relates to a CT image organ segmentation method based on convolutional neural network multi-dimensional fusion. The method comprises the steps of S1, training a Unet++ model through weights, training data and label data which are obtained through label calculation by means of an attention loss function; S2, training the Unet++ model by utilizing the training data, the label and a binary cross entropy loss function; S3, respectively obtaining two different segmentation results by utilizing the two obtained trained Unet++ models and the to-be-segmented data; and S4, fusing the twodifferent segmentation results. According to the method, the problem that some small blood vessels cannot be well segmented in the blood vessel segmentation problem of the fundus image is solved, so that the segmentation accuracy is improved.

The invention generally relates to compositions and methods for preferential vasoconstriction of smaller blood vessels relative to larger blood vessels. The compositions comprise highly selective alpha-2 adrenergic receptor agonists, at low concentrations, such as below 0.05% weight by volume. The compositions preferably comprise brimonidine. The compositions preferably have pH between about 5.5 and about 6.5.

The invention relates to a retinal vessel image segmentation method based on improved UNet + +, and belongs to the technical field of medical image processing. According to the method, a deep supervision network UNet + + is selected as an image segmentation network model, so that the use efficiency of features is improved; a MultiRes feature extraction module is introduced to improve the feature learning effect of small blood vessels in a low-contrast environment, the generalization ability of a network and the expression ability of a network structure are further improved by coordinating features learned by an image in different scales, and a SeNet channel attention module is added to perform extrusion and excitation operation after feature extraction to improve the accuracy of feature extraction of the small blood vessels in the low-contrast environment. Therefore, the receptive field in the feature extraction stage is enhanced, and the weight of a target related feature channel is improved. The improved UNet + + network model is verified based on a DRIVE retina image data set, and compared with an existing model, the evaluation indexes such as the overlapping ratio, the cross-parallel ratio, the accuracy and the sensitivity are improved to a certain extent.

A miniature cross stream thrombectomy catheter useful in small blood vessel thrombectomy procedures. An annulus near the distal end of the miniature cross stream thrombectomy catheter is formed between a hypo-tube and a proximally directed bore of a concentrically aligned flow director whereby jet orifices in the hypo-tube communicate with the annulus to direct jet flows of saline or other fluid around and about the annulus and to be directed proximally from the annulus to pass through one or more outflow orifices and thence to pass through one or more inflow orifices thereby creating an ablation flow therebetween which loosens and carries away thrombotic materials from the walls of a blood vessel.

Methods and devices are disclosed for providing access through tissue to a surgical site, such as anatomical cavities ranging in size from the abdomen to small blood vessels, such as veins and arteries, epidural, pleural and subarachnoid spaces, heart ventricles, as well as spinal and synovial cavities. In one exemplary embodiment, an access port is provided having one or more electrically expandable and contractible actuators that are adapted to change an orientation of the access port.

Methods are provided for reducing copper values for, by way of example, treating, preventing or ameliorating tissue damage such as, for example, tissue damage that may be caused by (i) disorders of the heart muscle (for example, cardiomyopathy or myocarditis) such as idiopathic cardiomyopathy, metabolic cardiomyopathy which includes diabetic cardiomyopathy, alcoholic cardiomyopathy, drug-induced cardiomyopathy, ischemic cardiomyopathy, and hypertensive cardiomyopathy, (ii) atheromatous disorders of the major blood vessels (macrovascular disease) such as the aorta, the coronary arteries, the carotid arteries, the cerebrovascular arteries, the renal arteries, the iliac arteries, the femoral arteries, and the popliteal arteries, (iii) toxic, drug-induced, and metabolic (including hypertensive and / or diabetic disorders of small blood vessels (microvascular disease) such as the retinal arterioles, the glomerular arterioles, the vasa nervorum, cardiac arterioles, and associated capillary beds of the eye, the kidney, the heart, and the central and peripheral nervous systems, (iv) plaque rupture of atheromatous lesions of major blood vessels such as the aorta, the coronary arteries, the carotid arteries, the cerebrovascular arteries, the renal arteries, the iliac arteries, the fermoral arteries and the popliteal arteries, (v) diabetes or the complications of diabetes.