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Virtual reality-based training for the diagnosis of prostate cancer
Prostate malignancies are the second leading cause of cancer deaths among men. The most common method of detecting this disease is digital rectal examination (DRE). Current DRE training is inadequate, since the number of patients that students can practice on is limited. Furthermore, allied care personnel do not train in screening for prostate cancer. Finally, there is no objective way to follow the improvement in DRE skills for medical personnel. This paper presents a virtual reality-based simulator that addresses the above problems. The prototype consists of a PHANToM haptic interface which provides feedback to the trainee's index finger, a motion restricting board, and an SGI workstation, which renders the patient's anatomy. Four types of prostates were modeled--normal, enlarged with no tumor, incipient malignancy (single tumor), and advanced malignancy (tumor cluster). Human factors studies were conducted on both nonmedical students and urology residents in order to quantify the system usefulness. After only five minutes of training, nonmedical students had a 67% correct diagnosis rate of malignant versus nonmalignant cases. This compared with 56% for urology residents in the same trials. Subjective evaluation by the residents pointed out the need to improve the virtual prostate model realism. A control group formed of urology residents performed the same trials on a modified Merck Procar simulator. The control group scored significantly better (96% correct diagnosis of malignancies). We conclude that the virtual prostate palpation simulator, while promising, needs significant improvement in both model realism and haptic interface hardware
Power Management for Low-Power Battery Operated Portable Systems Using Current-Mode Techniques
Three-dimensional ultrasound diagnosis of adenomyosis is not associated with adverse pregnancy outcome following single thawed euploid blastocyst transfer: prospective cohort study.
OBJECTIVES: The objectives of this study were (1) to assess the prevalence of ultrasound (US) features of adenomyosis in an infertile population undergoing in-vitro fertilization (IVF), (2) to define the inter- and intrarater agreement of three-dimensional (3D) US assessment of adenomyosis, and (3) to evaluate sonographic features of adenomyosis with respect to pregnancy outcome following transfer of a single thawed euploid blastocyst.
METHODS: This was a prospective cohort study. Subjects scheduled to undergo a single thawed euploid blastocyst transfer between April and December 2017 at a large IVF center were eligible for inclusion. Enrolled subjects underwent endometrial preparation for frozen embryo transfer. 3D-US was performed on the day prior to embryo transfer, with images stored for subsequent evaluation. Subjects then underwent transfer of a single thawed euploid blastocyst, and pregnancy outcomes were collected. All 3D-US volumes were de-identified and reviewed independently by five reproductive endocrinologists/infertility specialists with expertise in gynecological US for the presence of seven sonographic features of adenomyosis: global uterine enlargement, myometrial wall asymmetry, heterogeneous echogenicity, irregular junctional zone, myometrial cysts, fan-shaped shadowing and ill-defined myometrial lesions. Adenomyosis was considered to be present if the majority of the reviewers noted at least one of the seven sonographic features. Inter- and intrarater agreement was evaluated using Fleiss\u27s kappa. Clinical and cycle characteristics of subjects with and those without adenomyosis were compared. The primary outcome of interest was live birth rate. Secondary outcomes included clinical pregnancy rate and miscarriage rate. Logistic regression analysis was performed to account for potential confounders.
RESULTS: A total of 648 subjects were included. The prevalence of adenomyosis on US was 15.3% (99/648). On retrospective chart review, very few patients with adenomyosis had symptoms. The inter- and intrarater agreement amongst five independent specialists conducting the 3D-US assessments of adenomyosis were poor (κ = 0.23) and moderate (κ = 0.58), respectively. Subjects with adenomyosis were older (37.1 vs 35.9 years, P = 0.02) and more likely to undergo a gonadotropin-releasing hormone agonist downregulation protocol when compared with those without adenomyosis (12.1% vs 5.1%, P = 0.02). Clinical pregnancy (80.0% vs 75.0%) and live birth (69.5% vs 66.5%) rates were similar between the groups. When adjusting for potential confounders, there was no difference in the rate of clinical pregnancy (adjusted odds ratio (aOR), 1.47 (95% CI, 0.85-2.56)), miscarriage (aOR, 1.3 (95% CI, 0.62-2.72)) or live birth (aOR, 1.28 (95% CI, 0.78-2.08)) between subjects with and those without adenomyosis. No individual sonographic marker of adenomyosis was predictive of pregnancy outcome.
CONCLUSIONS: The inter-rater agreement of 3D-US assessment of adenomyosis is poor. Furthermore, sonographic markers of adenomyosis in asymptomatic patients may not be associated with altered pregnancy outcome following transfer of a single thawed euploid blastocyst. These findings suggest that routine screening for asymptomatic adenomyosis in an unselected infertile patient population undergoing frozen embryo transfer may not be warranted. © 2020 International Society of Ultrasound in Obstetrics and Gynecology