Summary
AIM: To determine the perifollicular vascular network and blood flow changes of the dominant preovulatory follicle using quantitative three-dimensional (3D) power Doppler analysis. METHODS: A ...total of 21 cycles were studied in spontaneously ovulating women who underwent folliculometry and 3D power Doppler angiography of perifollicular blood flow of the dominant preovulatory follicle on the day of human chorionic gonadotropin (hCG) administration and 24 h after it. RESULTS: At 24 h after the administration of hCG, increases were found in the area inside the biggest follicular circumference (8.48 ± 1.73 cm
2
vs.
9.30 ± 1.64 cm
2
), in the percentage of vessel volume inside the perifollicular capsule (3.58 ± 3.65%
vs.
7.76 ± 10.13%) and in total perifollicular blood volume (931.33 ± 1084.60
vs.
3486.00 ± 7272.34). Moreover, the rearrangement in blood volume distribution resulted in equalization of the contribution of each feeding vessel to total perifollicular blood flow. A more uniform vascular network resulting in decreased dominance of a single feeding vessel in total inflow was found (50.50 ± 28.18%
vs.
29.05 ± 14.14%). CONCLUSION: After the administration of hCG there was a visible increase in perifollicular capillary network volume, relative volume of blood, and balancing of blood inflow of each feeding vessel of the perifollicular circulation.
Background: Occurrence of early miscarriage in pregnancies accomplished by in vitro fertilisation procedures was studied, almost exclusively, in women in whom cleavage stage embryos were transferred. ...The primary objective of our retrospective study was to identify the factors predicting early miscarriage following the transfer of one or two blastocysts. Materials and Methods: Using the multivariate logistic regression model, we analyzed the parameters of 1020 sequential IVF/ICSI cycles with the transfer of one or two blastocysts, in which positive levels of βhCG were observed. Age of the patient, fertilization method, number of retrieved oocytes, number of developed, frozen and transferred blastocysts and their quality were analyzed as possible predictors for early spontaneous miscarriage. Results: The overall frequency of biochemical pregnancies in the observed group of patients was 6.6 % (67/1020). Biochemical pregnancies occurred somewhat more frequently following the transfer of one, rather than two blastocysts (9.05 % (23/254) vs. 5.8 % (44/763)). The rate of early clinical miscarriage was 13.3 % (136/1020), with the rate of miscarriage higher following the transfer of one as opposed to two blastocysts (15.3 % (39/254) vs. 12.7(97/763)). If biochemical pregnancies and early clinical miscarriages were observed together, the rate of early pregnancy losses in the overall sample studied was 19.9 % (203/1020), following the transfer of one blastocyst 24.4 % (62/254) and following the transfer of two 18.4 % (141/763). Using the multivariate logistic regression, we demonstrated that statistically significant predictors for early spontaneous miscarriages were the patient's age (OR = 1.098; 95 % CI 1.057-1.140, P < 0.001), the number of blastocysts transferred (OR = 0.592; 95 % CI 0.412-0.851, P = 0.005), the quality of blastocysts transferred (OR=0.666; 95 % CI 0.468-0.949; P = 0.024), as well as the number of blastocysts frozen (OR = 0.912; 95 % CI 0.832-0.999; P = 0.048). Conclusion: The transfer of optimal quality blastocyst(s) and transfer of two blastocysts were associated with a reduced rate of spontaneous miscarriages in pregnancies achieved by ART.
Background. Spontaneous miscarriage isn’t an unexpected complication either in early spontaneous or in ART pregnancy. Previous studies showed that incidence of SM was slightly increased in ART ...pregnancies in comparison with spontaneous ones after adjusting for maternal age and previous SM. Our objective was to examine the relationship between SM and embryo quality after transfer of one or two blastocysts. Materials and methods. The total of 1433 stimulated IVF and ICSI cycles achieved in our center in the period from 2001 to 2002 after SBT or DBT were retrospectively analyzed. Of these, in the final analysis we included only cases with positive βhCG for which complete data on pregnancy outcome were available – 418 cycles in total. Results. The mean age of patients was 32.2 ± 4.5 years. IVF was performed in 133 cases and ICSI was performed in 285 cases, SBT in 69 and DBT in 349. After SBT, SM rate was 11.6 % and after DBT it was 12.0 %. In SBT group we didn’t find significant relationship between embryo quality and SM (logistic regression: c2 = 0.88; p > 0.05). In this groups, using standard statistical tests, we also couldn’t find significant difference in SM rate between subgroups where optimal or suboptimal quality blastocyst was transferred (Yates corrected c2 test: p > 0.05, Student’s t-test: p > 0.05). In DBT group, we found a strong relationship between embryo quality and SM (logistic regression: c2 = 10.12; p < 0.01). After standard analysis, we confirmed significant difference between subgroups with different combinations of blastocyst quality: after transfer of both optimal blastocysts SM rate was 8.5 %, after transfer of optimal and suboptimal blastocyst SM rate was 10.1 % and after transfer of both suboptimal blastocyst SM rate was 25.4 % (Kruskal-Wallis test: p < 0.001; one-way ANOVA: p < 0.001). We confirmed strong relationship between age of the patients and SM (logistic regression: c2 = 14.57; p < 0.0001). Conclusions. In our study SM rate was 11.9 % which was lower than in previous reports; it was even at the lower limit of expected SM rate in general population. This discrepancy was probably the consequence of longer selection period of blastocysts in in vitro conditions. We didn’t find a significant relationship between SM and blastocyst quality after SBT, which was probably due to the small sample size. A strong relationship between SM and blastocyst quality after DBT was proved. We also confirmed a strong relationship between age of the patients and SM.
A large hymenal polyp in a 21-year-old virgin Borko, Elko; Dosen, Marko; Kavalar, Rajko ...
Acta dermatovenerologica Alpina, Panonica, et Adriatica,
12/2009, Letnik:
18, Številka:
4
Journal Article
Recenzirano
Pathological conditions of the hymen are rare in everyday medical practice. They are usually encountered in the pediatric patient population and are sometimes a matter of forensic interest. We report ...an interesting case of a large hymenal polyp in an adolescent virgin that presented only a cosmetic problem. The polyp was excised, the hymenal ring was preserved, and the sample was histologically verified.
Objective. The aim of the present work was to develop and test a flexible electrotactile stimulation system to provide real-time feedback to the prosthesis user. The system requirements were to ...accommodate the capabilities of advanced multi-DOF myoelectric hand prostheses and transmit the feedback variables (proprioception and force) using intuitive coding, with high resolution and after minimal training. Approach. We developed a fully-programmable and integrated electrotactile interface supporting time and space distributed stimulation over custom designed flexible array electrodes. The system implements low-level access to individual stimulation channels as well as a set of high-level mapping functions translating the state of a multi-DoF prosthesis (aperture, grasping force, wrist rotation) into a set of predefined dynamic stimulation profiles. The system was evaluated using discrimination tests employing spatial and frequency coding (10 able-bodied subjects) and dynamic patterns (10 able-bodied and 6 amputee subjects). The outcome measure was the success rate (SR) in discrimination. Main results. The more practical electrode with the common anode configuration performed similarly to the more usual concentric arrangement. The subjects could discriminate six spatial and four frequency levels with SR >90% after a few minutes of training, whereas the performance significantly deteriorated for more levels. The dynamic patterns were intuitive for the subjects, although amputees showed lower SR than able-bodied individuals (86% 10% versus 99% 3%). Significance. The tests demonstrated that the system was easy to setup and apply. The design and resolution of the multipad electrode was evaluated. Importantly, the novel dynamic patterns, which were successfully tested, can be superimposed to transmit multiple feedback variables intuitively and simultaneously. This is especially relevant for closing the loop in modern multifunction prostheses. Therefore, the proposed system is convenient for practical applications and can be used to implement sensory perception training and/or closed-loop control of myoelectric prostheses, providing grasping force and proprioceptive feedback.
Objective. Myoelectric activity volitionally generated by the user is often used for controlling hand prostheses in order to replicate the synergistic actions of muscles in healthy humans during ...grasping. Muscle synergies in healthy humans are based on the integration of visual perception, heuristics and proprioception. Here, we demonstrate how sensor fusion that combines artificial vision and proprioceptive information with the high-level processing characteristics of biological systems can be effectively used in transradial prosthesis control. Approach. We developed a novel context- and user-aware prosthesis (CASP) controller integrating computer vision and inertial sensing with myoelectric activity in order to achieve semi-autonomous and reactive control of a prosthetic hand. The presented method semi-automatically provides simultaneous and proportional control of multiple degrees-of-freedom (DOFs), thus decreasing overall physical effort while retaining full user control. The system was compared against the major commercial state-of-the art myoelectric control system in ten able-bodied and one amputee subject. All subjects used transradial prosthesis with an active wrist to grasp objects typically associated with activities of daily living. Main results. The CASP significantly outperformed the myoelectric interface when controlling all of the prosthesis DOF. However, when tested with less complex prosthetic system (smaller number of DOF), the CASP was slower but resulted with reaching motions that contained less compensatory movements. Another important finding is that the CASP system required minimal user adaptation and training. Significance. The CASP constitutes a substantial improvement for the control of multi-DOF prostheses. The application of the CASP will have a significant impact when translated to real-life scenarious, particularly with respect to improving the usability and acceptance of highly complex systems (e.g., full prosthetic arms) by amputees.
To effectively replace the human hand, a prosthesis should seamlessly respond to user intentions but also convey sensory information back to the user. Restoration of sensory feedback is rated highly ...by the prosthesis users, and feedback is critical for grasping in able-bodied subjects. Nonetheless, the benefits of feedback in prosthetics are still debated. The lack of consensus is likely due to the complex nature of sensory feedback during prosthesis control, so that its effectiveness depends on multiple factors (e.g., task complexity, user learning).
We evaluated the impact of these factors with a longitudinal assessment in six amputee subjects, using a clinical setup (socket, embedded control) and a range of tasks (box and blocks, block turn, clothespin and cups relocation). To provide feedback, we have proposed a novel vibrotactile stimulation scheme capable of transmitting multiple variables from a multifunction prosthesis. The subjects wore a bracelet with four by two uniformly placed vibro-tactors providing information on contact, prosthesis state (active function), and grasping force. The subjects also completed a questionnaire for the subjective evaluation of the feedback.
The tests demonstrated that feedback was beneficial only in the complex tasks (block turn, clothespin and cups relocation), and that the training had an important, task-dependent impact. In the clothespin relocation and block turn tasks, training allowed the subjects to establish successful feedforward control, and therefore, the feedback became redundant. In the cups relocation task, however, the subjects needed some training to learn how to properly exploit the feedback. The subjective evaluation of the feedback was consistently positive, regardless of the objective benefits. These results underline the multifaceted nature of closed-loop prosthesis control as, depending on the context, the same feedback interface can have different impact on performance. Finally, even if the closed-loop control does not improve the performance, it could be beneficial as it seems to improve the subjective experience.
Therefore, in this study we demonstrate, for the first time, the relevance of an advanced, multi-variable feedback interface for dexterous, multi-functional prosthesis control in a clinically relevant setting.
Objective. Technologically advanced assistive devices are nowadays available to restore grasping, but effective and effortless control integrating both feed-forward (commands) and feedback (sensory ...information) is still missing. The goal of this work was to develop a user friendly interface for the semi-automatic and closed-loop control of grasping and to test its feasibility. Approach. We developed a controller based on stereovision to automatically select grasp type and size and augmented reality (AR) to provide artificial proprioceptive feedback. The system was experimentally tested in healthy subjects using a dexterous hand prosthesis to grasp a set of daily objects. The subjects wore AR glasses with an integrated stereo-camera pair, and triggered the system via a simple myoelectric interface. Main results. The results demonstrated that the subjects got easily acquainted with the semi-autonomous control. The stereovision grasp decoder successfully estimated the grasp type and size in realistic, cluttered environments. When allowed (forced) to correct the automatic system decisions, the subjects successfully utilized the AR feedback and achieved close to ideal system performance. Significance. The new method implements a high level, low effort control of complex functions in addition to the low level closed-loop control. The latter is achieved by providing rich visual feedback, which is integrated into the real life environment. The proposed system is an effective interface applicable with small alterations for many advanced prosthetic and orthotic therapeutic rehabilitation devices.
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