Augmented reality simulator for CT-guided interventions.

INTRODUCTION: CT-guided interventions are taught using a mentored approach on real patients. It is well established that simulation is a valuable training tool in medicine. This project assessed the feasibility and acceptance of replicating a CT-guided intervention using a bespoke software application with an augmented reality head-mounted display (ARHMD). METHODS: A virtual patient was generated using a CT dataset obtained from The Cancer Imaging Archive. A surface mesh of a virtual patient was projected into the field-of-view of the operator. ChArUco markers, placed on both the needle and agar jelly phantom, were tracked using RGB cameras built into the ARHMD. A virtual CT slice simulating the needle position was generated on voice command. The application was trialled by senior interventional radiologists and trainee radiologists with a structured questionnaire evaluating face validity and technical aspects. RESULTS: Sixteen users trialled the application and feedback was received from all. Eleven felt the accuracy and realism was adequate for training and twelve felt more confident about their CT biopsy skills after this training session. DISCUSSION: The study showed the feasibility of simulating a CT-guided procedure with augmented reality and that this could be used as a training tool. KEY POINTS: • Simulating a CT-guided procedure using augmented reality is possible. • The simulator developed could be an effective training tool for clinical practical skills. • Complexity of cases can be tailored to address the training level demands.

Quantitative analysis of technological innovation in minimally invasive surgery.

BACKGROUND: In the past 30 years surgical practice has changed considerably owing to the advent of minimally invasive surgery (MIS). This paper investigates the changing surgical landscape chronologically and quantitatively, examining the technologies that have played, and are forecast to play, the largest part in this shift in surgical practice. METHODS: Electronic patent and publication databases were searched over the interval 1980-2011 for ('minimally invasive' OR laparoscopic OR laparoscopy OR 'minimal access' OR 'key hole') AND (surgery OR surgical OR surgeon). The resulting patent codes were allocated into technology clusters. Technology clusters referred to repeatedly in the contemporary surgical literature were also included in the analysis. Growth curves of patents and publications for the resulting technology clusters were then plotted. RESULTS: The initial search revealed 27,920 patents and 95,420 publications meeting the search criteria. The clusters meeting the criteria for in-depth analysis were: instruments, image guidance, surgical robotics, sutures, single-incision laparoscopic surgery (SILS) and natural-orifice transluminal endoscopic surgery (NOTES). Three patterns of growth were observed among these technology clusters: an S-shape (instruments and sutures), a gradual exponential rise (surgical robotics and image guidance), and a rapid contemporaneous exponential rise (NOTES and SILS). CONCLUSION: Technological innovation in MIS has been largely stagnant since its initial inception nearly 30 years ago, with few novel technologies emerging. The present study adds objective data to the previous claims that SILS, a surgical technique currently adopted by very few, represents an important part of the future of MIS.

The heritabilities, phenotypic correlations, and genetic correlations of lean color and palatability measures from longissimus muscle in beef cattle.

Data from a study conducted over 5 yr were analyzed to determine heritability estimates of LM lean color, as measured by subjective scoring and Hunter Colorimeter readings, and palatability, as measured by trained sensory panelists and Warner-Bratzler shear force (WBSF). Phenotypic and genetic correlations were determined between each of the measures of palatability and color. There were 1,066 cattle representing 12 different breeds in the study. Subjective lean color and a* (redness) and b* (yellowness) values were moderately heritable, 0.34 ± 0.122, 0.29 ± 0.115 and 0.28 ± 0.120, respectively, whereas the L* (lightness) was lowly heritable, 0.09 ± 0.087. The heritability of WBSF was moderately heritable ranging from 0.23 ± 0.114 (3 d) to 0.42 ± 0.148 (21 d). Sustained tenderness, as measured by sensory panelists, was found to be moderately heritable ranging from 0.16 ± 0.108 (21 d) to 0.33 ± 0.135 (14 d). Sustained juiciness and beef flavor, as measured by sensory panelists, were found to be lowly to moderately heritable ranging from 0.00 ± 0.089 (21 d) to 0.18 ± 0.105 (14 d) and 0.00 ± 0.080 (7 d) to 0.18 ± 0.110 (21 d), respectively. The significant phenotypic correlations were those between WBSF and subjective lean color, L* value, and a* value; both initial and sustained tenderness as well as beef flavor were correlated with subjective lean color and L* value. Flavor intensity and overall mouthfeel were associated with subjective lean color, L* value, a* value, and b* value. Both a* and b* values were highly correlated genetically with WBSF, -0.71 and -0.72, respectively, and subjective lean color was moderately correlated with WBSF, -0.46. The genetic correlation between subjective lean color and initial tenderness was also high, 0.56, whereas that between a* value and initial tenderness was 0.43, which was similar to that found between b* value and initial tenderness, 0.44. The genetic correlations between subjective lean color, a* value, and b* value with sustained tenderness were all high at 0.58, 0.70, and 0.58, respectively. The genetic correlations between a* value and b* value with beef flavor were low to moderate at 0.12 and 0.19, respectively, whereas that between subjective lean color and beef flavor was high, 0.64. The genetic correlations between a* value, b* value, and lean color with sustained juiciness were all moderate correlations at -0.35, -0.23, and -0.45, respectively. The genetic correlations between a* value and b* value with overall mouthfeel were high at 0.80 and 0.79, respectively, whereas that between subjective lean color and overall mouthfeel was moderate, 0.46. In conclusion, regardless of measurement technique of lean color, it was not only heritable but was also moderately to highly correlated with measurements of palatability in beef from LM.