In surgical practice, small metallic instruments are frequently used to perform various tasks inside the human body. We address the problem of their accurate localization in the tissue. Recent ...experiments using medical ultrasound have shown that this modality is suitable for real-time visualization of anatomical structures as well as the position of surgical instruments. We propose an image- processing algorithm that permits automatic estimation of the position of a line-segment-shaped object. This method was applied to the localization of a thin metallic electrode in biological tissue. We show that the electrode axis can be found through maximizing the parallel integral projection transform that is a form of the Radon transform. To accelerate this step, hierarchical mesh-grid algorithm is implemented. Once the axis position is known, localization of the electrode tip is performed. The method was tested on simulated images, on ultrasound images of a tissue mimicking phantom containing a metallic electrode, and on real ultrasound images from breast biopsy. The results indicate that the algorithm is robust with respect to variations in electrode position and speckle noise. Localization accuracy is of the order of hundreds of micrometers and is comparable to the ultrasound system axial resolution.
We have measured the cross section σ(e+e−→π+π−γ) at an energy W=mϕ=1.02 GeV with the KLOE detector at the electron–positron collider DAΦNE. From the dependence of the cross section on the invariant ...mass of the two-pion system, we extract σ(e+e−→π+π−) for the mass range 0.35<s<0.95 GeV2. From this result, we calculate the pion form factor and the hadronic contribution to the muon anomaly, aμ.
The ϕ-meson leptonic widths, Γee and Γμμ, are obtained, respectively, from the e+e− forward–backward asymmetry and the μ+μ− cross section around the ϕ-mass energy. We find Γee=1.32±0.05±0.03 keV and ...ΓeeΓμμ=1.320±0.018±0.017 keV. These results, compatible with Γee=Γμμ, provide a precise test of lepton universality. Combining the two results gives Γℓℓ(ϕ)=1.320±0.023 keV.
The KLOE experiment has been collecting data since april 1999 at the DAΦNE collider in Frascati. A statistics of about 0.45
f
b
−1
has been analyzed. The latest results concerning the study of the
ϕ ...radiative decays and of the kaon decays are illustrated in this paper.
We have measured the absolute branching ratio BR(K±→π±π0π0) with the KLOE detector at the DAΦNE e+e− collider. We collected ∼3.3×107 tagged charged kaons, from the reaction e+e−→ϕ→K+K−. We find ...BR(K±→π±π0π0)=(1.763±0.013stat±0.022syst)×10−2.
Neutral kaons provide one of the systems most sensitive to quantum mechanics and
CPT violation. Models predicting quantum mechanics violation, also related to
CPT violation, have been tested at the ...CPLEAR and KLOE experiments. In this report results of CPLEAR obtained by studying the time evolution of single and two entangled kaons are reviewed. New or improved limits on decoherence and
CPT violation parameters have been obtained by KLOE studying the quantum interference in the channel
ϕ
→
K
S
K
L
→
π
+
π
−
π
+
π
−
. No deviations from the expectations of quantum mechanics and
CPT symmetry have been observed.
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