A methodology for estimating the force distribution that occurs along a needle shaft during insertion is described. An experimental system for measuring planar tissue phantom deformation during needle insertions has been developed and is presented. A two-dimensional linear elastostatic material model, discretised using the finite element method, is used to derive contact force information that ...

AIM To analyze the influence of the needle type, insertion depth, and irrigant flow rate on irrigant flow pattern, flow velocity, and apical pressure by ex-vivo based endodontic irrigation computational fluid dynamics (CFD) analysis. METHODS Human upper canine root canal was prepared using rotary files. Contrast fluid was introduced in the root canal and scanned by computed tomography (CT) pr...

Purpose The purpose of this study was to evaluate the dispersion of intravitreally injected solutions and investigate the influence of varying injection techniques. Methods This was a prospective study using enucleated porcine eyes and ultra-high-resolution computed tomography (UHRCT) scanning to visualize iomeprol intravitreal dispersion. Sixty eyes were divided over 12 different groups acco...

Needle insertion is the most common procedure of minimally invasive interventions. During insertion into a soft tissue, the needle with bevel tip can deflect due to the asymmetric forces acting on the tip of the needle. In this paper, a mechanics-based model is developed to predict the needle deflection. In the model, the needle is considered as a cantilever beam supported by a series of nonlin...

Background: Palpation of anatomic landmarks is difficult in pregnant patients due to physiological changes. This can complicate epidural catheterization and determination of needle insertion site to place an epidural catheter. The purpose of our study was to compare prepuncture lumbar ultrasonography and palpation method for epidural needle insertion among pregnant. Methods: Forty parturients s...

Figure 1. Typical out-of-plane artifacts from high-attenuation objects at consecutive heights in the reconstructed volume. Top: needle insertion position is parallel to the X-ray emitter motion lane. Bottom: Needle insertion direction is perpendicular to the X-ray emitter motion lane. Pictures courtesy of Siemens Healthcare Sector. Metal Artifact Reduction of Biopsy Needles in Digital Breast To...

Emphasis has been placed on improving patient outcomes in healthcare management. Significant patient morbidity and mortality exists from inappropriate procedural technique and percutaneous catheter needle insertion procedures have been linked to medical complications. Healthcare trainees learn these procedures through trial and error and most existing simulators are synthetic tissue based and l...

Under ultrasound guided needle insertion therapy, surgeons have had much burden finding the tumor of the patient, particularly when the target tumor is moving due to the respiration or heartbeat. We researched on the development of a new needle insertion instrument which can track a moving objective based on visual servo control and tumor specific active contour models.

BACKGROUND AND AIMS Ultrasound imaging before neuraxial blocks was reported to improve the ease of insertion and minimize the traumatic trials. However, the data about the use of ultrasound in thoracic epidural block are scanty. In this study, pre-insertion ultrasound scanning was compared to traditional manual palpation technique for insertion of the thoracic epidural catheter in abdominal ope...

INTRODUCTION MRI can be an important tool in the early detection of breast lesions and may provide improved capability for imaging-guided interventions (IGI) and therapies (IGT). During an MR-guided breast intervention, placement of a needle or probe requires accurate localization of the target. An unsuccessful needle placement can occur if the target moves from its original position during the...