23 research outputs found
CrossMoDA 2021 challenge: Benchmark of Cross-Modality Domain Adaptation techniques for Vestibular Schwannoma and Cochlea Segmentation
Domain Adaptation (DA) has recently raised strong interests in the medical
imaging community. While a large variety of DA techniques has been proposed for
image segmentation, most of these techniques have been validated either on
private datasets or on small publicly available datasets. Moreover, these
datasets mostly addressed single-class problems. To tackle these limitations,
the Cross-Modality Domain Adaptation (crossMoDA) challenge was organised in
conjunction with the 24th International Conference on Medical Image Computing
and Computer Assisted Intervention (MICCAI 2021). CrossMoDA is the first large
and multi-class benchmark for unsupervised cross-modality DA. The challenge's
goal is to segment two key brain structures involved in the follow-up and
treatment planning of vestibular schwannoma (VS): the VS and the cochleas.
Currently, the diagnosis and surveillance in patients with VS are performed
using contrast-enhanced T1 (ceT1) MRI. However, there is growing interest in
using non-contrast sequences such as high-resolution T2 (hrT2) MRI. Therefore,
we created an unsupervised cross-modality segmentation benchmark. The training
set provides annotated ceT1 (N=105) and unpaired non-annotated hrT2 (N=105).
The aim was to automatically perform unilateral VS and bilateral cochlea
segmentation on hrT2 as provided in the testing set (N=137). A total of 16
teams submitted their algorithm for the evaluation phase. The level of
performance reached by the top-performing teams is strikingly high (best median
Dice - VS:88.4%; Cochleas:85.7%) and close to full supervision (median Dice -
VS:92.5%; Cochleas:87.7%). All top-performing methods made use of an
image-to-image translation approach to transform the source-domain images into
pseudo-target-domain images. A segmentation network was then trained using
these generated images and the manual annotations provided for the source
image.Comment: Submitted to Medical Image Analysi
Systems and methods for stable haptic feedback over packet-switched networks
Providing haptic feedback to a user over a packet-switched network includes sensing movement of a haptic device by a user, the haptic device being configured to control a first virtual object within a virtual environment, transmitting data associated with the movement of the haptic device from a client computer to a remote server via the packet-switched network, the server modeling movement of the first virtual object in the virtual environment and estimating an orientation and a position of the first virtual object within the virtual environment, the server determining a type of tactile feedback to be provided to the user, the server transmitting the type of tactile feedback data to the client computer via the packet-switched network, and providing tactile feedback to the user with the haptic device
Laparoscopic tool for grasping tissue
A laparoscopic tool includes a base having a bore that receives the proximal end of an elongate outer tube having a lumen in axial alignment with the bore. An elongate inner rod is slideably mounted in the lumen and the bore. A clamp is detachably secured to a distal end of the elongate inner rod. A handle controlled by a user advances and retracts the inner rod. A nitinol clamp is connected to the distal end of the inner rod and an electrically conductive suture thread holds the clamp to the inner rod. A wedge block positioned at the proximal end of the inner rod has a slit that releasably engages the suture thread so that the suture thread is pulled until it is taut and wedged into the slit. The clamp closes when heated by an electrical current flowing through the suture thread and opens when the current stops
Laparoscopic tool for grasping tissue
A laparoscopic tool includes a base having a bore that receives the proximal end of an elongate outer tube having a lumen in axial alignment with the bore. An elongate inner rod is slideably mounted in the lumen and the bore. A clamp is detachably secured to a distal end of the elongate inner rod. A handle controlled by a user advances and retracts the inner rod. A nitinol clamp is connected to the distal end of the inner rod and an electrically conductive suture thread holds the clamp to the inner rod. A wedge block positioned at the proximal end of the inner rod has a slit that releasably engages the suture thread so that the suture thread is pulled until it is taut and wedged into the slit. The clamp closes when heated by an electrical current flowing through the suture thread and opens when the current stops
Universal laparoscopic suturing device
A laparoscopic suturing device includes a handle and a shaft mounted to the handle. A toggle knob is adapted to rotate the shaft about its longitudinal axis. A pair of opposed jaws, each having a hollow structure, open and close relative to one another. A needle carrier and a needle holder are respectively slideably disposed in a lumen of a first and a second jaw. A needle has first and second pointed ends and is adapted to be press fit into the lumen of the first jaw with the first pointed end exposed and alternatively into the lumen of the second jaw with the second pointed end exposed. A spring-loaded pusher advances and retracts the needle carrier when the toggle knob is in a first position and advances and retracts the needle holder when in a second position. The tool assists a surgeon in suturing tissue captured between the jaws
Drug delivery device for ovarian cancer
A drug delivery device has been designed to directly deliver an agent to the ovaries through direct contact with the fallopian tubes. The device consists of three main components: a tubular inserter, a cylindrical chamber and a plunger. The device is a single-use applicator designed in a shape similar to a tampon to facilitate its insertion through the vagina and into the uterus. Positioning of the device centrally in the uterus is accomplished through the use of ultrasound. The chamber is inserted into the tubular inserter. Adjusting the length of the chamber inserted into the tubular inserter controls the amount of tubing released from the apertures in the tubular inserter. Ultrasound is used to ensure the proper placement of each tube at the entrance of each fallopian tube. The plunger is inserted into the chamber and adjustment of the plunger controls the amount of the agent released into the tubes
Automatic Vertebra Segmentation on Dynamic Magnetic Resonance Imaging
The automatic extraction of the vertebra’s shape from dynamic magnetic resonance imaging (MRI) could improve understanding of clinical conditions and their diagnosis. It is hypothesized that the shape of the sacral curve is related to the development of some gynecological conditions such as pelvic organ prolapse (POP). POP is a critical health condition for women and consists of pelvic organs dropping from their normal position. Dynamic MRI is used for assessing POP and to complement clinical examination. Studies have shown some evidence on the association between the shape of the sacral curve and the development of POP. However, the sacral curve is currently extracted manually limiting studies to small datasets and inconclusive evidence. A method composed of an adaptive shortest path algorithm that enhances edge detection and linking, and an improved curve fitting procedure is proposed to automate the identification and segmentation of the sacral curve on MRI. The proposed method uses predetermined pixels surrounding the sacral curve that are found through edge detection to decrease computation time compared to other model-based segmentation algorithms. Moreover, the proposed method is fully automatic and does not require user input or training. Experimental results show that the proposed method can accurately identify sacral curves for nearly 91% of dynamic MRI cases tested in this study. The proposed model is robust and can be used to effectively identify bone structures on MRI
Automatic Vertebra Segmentation on Dynamic Magnetic Resonance Imaging
The automatic extraction of the vertebra’s shape from dynamic magnetic resonance imaging (MRI) could improve understanding of clinical conditions and their diagnosis. It is hypothesized that the shape of the sacral curve is related to the development of some gynecological conditions such as pelvic organ prolapse (POP). POP is a critical health condition for women and consists of pelvic organs dropping from their normal position. Dynamic MRI is used for assessing POP and to complement clinical examination. Studies have shown some evidence on the association between the shape of the sacral curve and the development of POP. However, the sacral curve is currently extracted manually limiting studies to small datasets and inconclusive evidence. A method composed of an adaptive shortest path algorithm that enhances edge detection and linking, and an improved curve fitting procedure is proposed to automate the identification and segmentation of the sacral curve on MRI. The proposed method uses predetermined pixels surrounding the sacral curve that are found through edge detection to decrease computation time compared to other model-based segmentation algorithms. Moreover, the proposed method is fully automatic and does not require user input or training. Experimental results show that the proposed method can accurately identify sacral curves for nearly 91% of dynamic MRI cases tested in this study. The proposed model is robust and can be used to effectively identify bone structures on MRI