To evaluate the feasibility and describe the relevant differences between robotic cholecystectomy (RC) and laparoscopic cholecystectomy in a canine model.
Canine cadavers (n = 4) weighing between 30 ...and 42 kg.
Dogs were positioned in dorsal recumbency. A surgical robot was used to perform the RC and was placed at the cranial aspect of the surgical table. One 12-mm and 3 8-mm robotic ports and 1 5-mm laparoscopic port were placed as needed to perform the RC. The specific steps of the procedure were described and timed. Perceived differences between psychomotor skills between robotics and laparoscopy were noted.
RC was successful in all dogs, but minor intraoperative complications did occur during the manipulation of the gallbladder in 1 dog. The median length of time for ports to be appropriately docked was 19.5 minutes, and the median procedure time was 119.5 minutes. Psychomotor skills specific to robotics can be learned during this procedure.
Robotic cholecystectomy is feasible. RC allowed for experience with the different psychomotor skills utilized with robotic instrumentation and may be an appropriate training procedure for veterinary surgeons wishing to gain basic experience with robotic instrumentation.
Background
Assess the relevance of a canine model in robot‐assisted radical prostatectomy (RARP) training.
Methods
Step‐by‐step RARP was performed in five dog cadavers using a Da Vinci Si® Surgical ...Robot (Intuitive Surgical, Inc.). The steps were defined according to the RARP score, a validated training tool describing 17 key steps and four levels of difficulty; each step was scored to reflect the anatomical and technical similarities, realism of dissection, and face validity of the canine model compared to the human procedure.
Results
Fourteen steps were performed during each procedure. Face validity was scored as high or very high for five of the nine steps of difficulty levels 1 and 2 as well as five of the eight steps of difficulty levels 3 and 4, especially nerve preservation, vesicourethral anastomosis and lymph node dissection.
Conclusions
The cadaveric canine model seems to be a realistic and relevant training model for key steps of RARP.
Full text
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Abstract
We present spectrophotometry spanning 1–5
μ
m of 51 Eridani b, a 2–10
planet discovered by the Gemini Planet Imager Exoplanet Survey. In this study, we present new
K
1 (1.90–2.19
μ
m) and
K
...2 (2.10–2.40
μ
m) spectra taken with the Gemini Planet Imager as well as an updated
L
P
(3.76
μ
m) and new
M
S
(4.67
μ
m) photometry from the NIRC2 Narrow camera. The new data were combined with
J
(1.13–1.35
μ
m) and
H
(1.50–1.80
μ
m) spectra from the discovery epoch with the goal of better characterizing the planet properties. The 51 Eri b photometry is redder than field brown dwarfs as well as known young T-dwarfs with similar spectral type (between T4 and T8), and we propose that 51 Eri b might be in the process of undergoing the transition from L-type to T-type. We used two complementary atmosphere model grids including either deep iron/silicate clouds or sulfide/salt clouds in the photosphere, spanning a range of cloud properties, including fully cloudy, cloud-free, and patchy/intermediate-opacity clouds. The model fits suggest that 51 Eri b has an effective temperature ranging between 605 and 737 K, a solar metallicity, and a surface gravity of log(
g
) = 3.5–4.0 dex, and the atmosphere requires a patchy cloud atmosphere to model the spectral energy distribution (SED). From the model atmospheres, we infer a luminosity for the planet of −5.83 to −5.93 (
), leaving 51 Eri b in the unique position of being one of the only directly imaged planets consistent with having formed via a cold-start scenario. Comparisons of the planet SED against warm-start models indicate that the planet luminosity is best reproduced by a planet formed via core accretion with a core mass between 15 and 127
.
Abstract
Using the Gemini Planet Imager located at Gemini South, we measured the near-infrared (1.0–2.4
μ
m) spectrum of the planetary companion to the nearby, young star
β
Pictoris. We compare the ...spectrum obtained with currently published model grids and with known substellar objects and present the best matching models as well as the best matching observed objects. Comparing the empirical measurement of the bolometric luminosity to evolutionary models, we find a mass of 12.9 ± 0.2
, an effective temperature of 1724 ± 15 K, a radius of 1.46 ± 0.01
, and a surface gravity of
dex (cgs). The stated uncertainties are statistical errors only, and do not incorporate any uncertainty on the evolutionary models. Using atmospheric models, we find an effective temperature of 1700–1800 K and a surface gravity of
–4.0 dex depending upon the model. These values agree well with other publications and with “hot-start” predictions from planetary evolution models. Further, we find that the spectrum of
β
Pic b best matches a low surface gravity L2 ± 1 brown dwarf. Finally, comparing the spectrum to field brown dwarfs, we find the the spectrum best matches 2MASS J04062677–381210 and 2MASS J03552337+1133437.
We present the first results from the polarimetry mode of the Gemini Planet Imager (GPI), which uses a new integral field polarimetry architecture to provide high contrast linear polarimetry with ...minimal systematic biases between the orthogonal polarizations. We describe the design, data reduction methods, and performance of polarimetry with GPI. Point-spread function (PSF) subtraction via differential polarimetry suppresses unpolarized starlight by a factor of over 100, and provides sensitivity to circumstellar dust reaching the photon noise limit for these observations. In the case of the circumstellar disk around HR 4796A, GPI's advanced adaptive optics system reveals the disk clearly even prior to PSF subtraction. In polarized light, the disk is seen all the way in to its semi-minor axis for the first time. The disk exhibits surprisingly strong asymmetry in polarized intensity, with the west side > ~9 times brighter than the east side despite the fact that the east side is slightly brighter in total intensity. Based on a synthesis of the total and polarized intensities, we now believe that the west side is closer to us, contrary to most prior interpretations. Forward scattering by relatively large silicate dust particles leads to the strong polarized intensity on the west side, and the ring must be slightly optically thick in order to explain the lower brightness in total intensity there. These findings suggest that the ring is geometrically narrow and dynamically cold, perhaps shepherded by larger bodies in the same manner as Saturn's F ring.
ABSTRACT We present new H (1.5-1.8 m) photometric and K1 (1.9-2.2 m) spectroscopic observations of the young exoplanet HD 95086 b obtained with the Gemini Planet Imager. The H-band magnitude has been ...significantly improved relative to previous measurements, whereas the low-resolution K1 ( ) spectrum is featureless within the measurement uncertainties and presents a monotonically increasing pseudo-continuum consistent with a cloudy atmosphere. By combining these new measurements with literature photometry, we compare the spectral energy distribution (SED) of the planet to other young planetary-mass companions, field brown dwarfs, and to the predictions of grids of model atmospheres. HD 95086 b is over a magnitude redder in color than 2MASS J12073346-3932539 b and HR 8799 c and d, despite having a similar magnitude. Considering only the near-infrared measurements, HD 95086 b is most analogous to the brown dwarfs 2MASS J2244316+204343 and 2MASS J21481633+4003594, both of which are thought to have dusty atmospheres. Morphologically, the SED of HD 95086 b is best fit by low temperature ( = 800-1300 K), low surface gravity spectra from models which simulate high photospheric dust content. This range of effective temperatures is consistent with field L/T transition objects, but the spectral type of HD 95086 b is poorly constrained between early L and late T due to its unusual position the color-magnitude diagram, demonstrating the difficulty in spectral typing young, low surface gravity substellar objects. As one of the reddest such objects, HD 95086 b represents an important empirical benchmark against which our current understanding of the atmospheric properties of young extrasolar planets can be tested.
We present H band spectroscopic and H photometric observations of HD 100546 obtained with the Gemini Planet Imager and the Magellan Visible AO camera. We detect H band emission at the location of the ...protoplanet HD 100546 b, but show that the choice of data processing parameters strongly affects the morphology of this source. It appears point-like in some aggressive reductions, but rejoins an extended disk structure in the majority of the others. Furthermore, we demonstrate that this emission appears stationary on a timescale of 4.6 years, inconsistent at the 2 level with a Keplerian clockwise orbit at 59 au in the disk plane. The H band spectrum of the emission is inconsistent with any type of low effective temperature object or accreting protoplanetary disk. It strongly suggests a scattered-light origin, as this is consistent with the spectrum of the star and the spectra extracted at other locations in the disk. A non-detection at the 5 level of HD 100546 b in differential H imaging places an upper limit, assuming the protoplanet lies in a gap free of extinction, on the accretion luminosity of 1.7 × 10−4 L and for 1 RJup. These limits are comparable to the accretion luminosity and accretion rate of T-Tauri stars or LkCa 15 b. Taken together, these lines of evidence suggest that the H band source at the location of HD 100546 b is not emitted by a planetary photosphere or an accreting circumplanetary disk but is a disk feature enhanced by the point-spread function subtraction process. This non-detection is consistent with the non-detection in the K band reported in an earlier study but does not exclude the possibility that HD 100546 b is deeply embedded.
ABSTRACT We present the first scattered light detections of the HD 106906 debris disk using the Gemini/Gemini Planet Imager in the infrared and Hubble Space Telescope (HST)/Advanced Camera for ...Surveys in the optical. HD 106906 is a 13 Myr old F5V star in the Sco-Cen association, with a previously detected planet-mass candidate HD 106906b projected 650 AU from the host star. Our observations reveal a near edge-on debris disk that has a central cleared region with radius ∼50 AU, and an outer extent >500 AU. The HST data show that the outer regions are highly asymmetric, resembling the "needle" morphology seen for the HD 15115 debris disk. The planet candidate is oriented ∼21° away from the position angle of the primary's debris disk, strongly suggesting non-coplanarity with the system. We hypothesize that HD 106906b could be dynamically involved in the perturbation of the primary's disk, and investigate whether or not there is evidence for a circumplanetary dust disk or cloud that is either primordial or captured from the primary. We show that both the existing optical properties and near-infrared colors of HD 106906b are weakly consistent with this possibility, motivating future work to test for the observational signatures of dust surrounding the planet.
ABSTRACT We present H-band observations of β Pic with the Gemini Planet Imager's (GPI's) polarimetry mode that reveal the debris disk between ∼0 3 (6 AU) and ∼1 7 (33 AU), while simultaneously ...detecting β Pic b. The polarized disk image was fit with a dust density model combined with a Henyey-Greenstein scattering phase function. The best-fit model indicates a disk inclined to the line of sight ( ) with a position angle (PA) (slightly offset from the main outer disk, ), that extends from an inner disk radius of to well outside GPI's field of view. In addition, we present an updated orbit for β Pic b based on new astrometric measurements taken in GPI's spectroscopic mode spanning 14 months. The planet has a semimajor axis of , with an eccentricity The PA of the ascending node is offset from both the outer main disk and the inner disk seen in the GPI image. The orbital fit constrains the stellar mass of β Pic to Dynamical sculpting by β Pic b cannot easily account for the following three aspects of the inferred disk properties: (1) the modeled inner radius of the disk is farther out than expected if caused by β Pic b; (2) the mutual inclination of the inner disk and β Pic b is when it is expected to be closer to zero; and (3) the aspect ratio of the disk ( ) is larger than expected from interactions with β Pic b or self-stirring by the disk's parent bodies.
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