Mechanism Of Erection Research Articles

The Natural (non-invasive) Erection Test: Is it a reliable alternative to the artificial erection test?

To test the accuracy and reliability of the natural erection test (NET) as compared to the artificial erection test in assessing penile curvature in hypospadias. 50 children underwent both natural and artificial erection tests intraoperatively between January 2020 and October 2021. These included 5 glandular, 26 distal, 9 proximal, and 10 perineal hypospadias patients with curvature. The mean follow up period was 20 months (range 16-37). Under anesthesia, the curvature was assessed before degloving, then after degloving using both the natural and the artificial erection test. The NET test was repeated after curvature correction (3 times per patient). The measurements were analyzed using paired t-test. Two fingers of the left hand press just below the symphysis pubis to stop blood drainage from the penis and two fingers of the right hand massage the blood from the perineum distally into the penis until it becomes hard without tourniquet. The standard artificial erection test was performed using saline injected through a butterfly needle into the corporeal bodies without tourniquet. Photos were taken of both tests using the exact angle and angle of curvature was measured using Angle Meter App. There was no statistically significant difference between both erection tests with a P value of 0.705. The Bland-Altman plot also showed that all studied children have a difference in their natural and artificial erection tests within the limits of agreements. Erection is commonly induced using the artificial saline injected erection test first described by Gittes and less commonly using pharmaceutical erection test first described by Perovic. The severity of chordee apparent during artificial erection test varies with the amount of pressure used during injection. Also, it is difficult to place the tourniquet proximal enough to detect chordee at the base of the penis. It may be associated with hematoma formation, oedema, postoperative pain and the need for multiple punctures to assess the curvature before and after repair. Disadvantages of the pharmacological-induced erections in hypospadias include increased blood loss during erection, additional cost, and the need for a reversal agent. The natural erection test mimic the normal erection mechanism and may avoid all these potential disadvantages. The study showed that the natural erection test is easy to perform, non-invasive, non-traumatic and can be repeated several times intraoperatively without the need of repeated puncturing of the corpora cavernosa and avoids the potential risks and complications of the artificial erection test.

Neural Network-Based Dual-Cylinder Synchronous Control of a Multi-Link Erection Mechanism

A dual-cylinder erection mechanism, in which two telescopic cylinders physically connect to a load, is a nonlinear system with model uncertainties and coupled dynamics. In this paper, a novel synchronous control algorithm with thrust-allocation law is proposed for eliminating the excessive internal forces caused by the unbalanced rotation and lateral moments during the erection process. With regulated internal forces, the “pull and drag” issue is attenuated and better synchronization performance is attained. For improved tracking accuracy, the inter-stage collision dynamics of the telescopic cylinder are considered for model compensation to enhance stage-changing and in-position performance. A radial basis function (RBF) neural network is utilized to estimate the model uncertainties and external disturbances, which alleviates reliance upon the accuracy of a system model for controller implementation. As a result, theoretical analysis revealed that the semi-global asymptotic stability and synchronized motion performance with decreased internal forces can be achieved via the presented synchronous controller with thrust-allocation strategy. Contrasting simulations were implemented on a multi-link erection mechanism and the results confirmed the superiority and effectiveness of the proposed synchronous control algorithm.

Ингибиторы фосфодиэстеразы 5-го типа: клиническая эффективность и роль в терапии эректильной дисфункции

This article discusses the physiological mechanisms of erection and the pathophysiological basis of erectile dysfunction. Parameters characterizing the features of the pharmacokinetics and pharmacodynamics of drugs from the group of phosphodiesterase type 5 inhibitors (PDE-5i) are presented. The clinical efficacy and possible adverse effects of the most significant PDE-5i are considered. These include sildenafil, tadalafil, vardenafil, udenafil, avanafil. There are also data on less known PDE-5i, which include lodenafil and mirodenafil.

122 Regimented Phosphodiesterase Type 5 Inhibitor Use Reduces Emergency Department Visits for Recurrent Ischemic Priapism

Priapism is an erection disorder defined by an undesirable and often painful penile erection that persists in the absence of sexual desire or arousal. Recurrent ischemic priapism (RIP) manifests as multiple repetitive episodes over time and can have potentially irreversible pathologic consequences. The ideal strategy for managing RIP is preventative therapy. Current treatment options are often ineffective, have significant adverse effects, and have limited evidence. A recently recognized proposal has been the use of regimented phosphodiesterase type 5 inhibitor (regPDE5i) therapy intended to modulate the deranged regulatory mechanisms of penile erection in RIP. Previous reports on this strategy, mostly in small clinical trials and case series, have documented encouraging outcomes. However, its effectiveness as a treatment in use more extensively in real-world clinical practice remains to be shown.

Load simulation analysis of a new erection system based on the gas-assisted drive erecting scheme

To improve the traditional erecting process with lower velocity and smaller power density, a new erection system is designed based on the hybrid drive of gas and electric cylinder, witch could erect quickly without increasing the power of the whole machine. According to the prescribed rotational motion and the rotational differential equation of the erection mechanism, the computational models of the related characteristic parameters in erection process were set up. Taking some parameters of a missile as boundary conditions, the models were simulated in MATLAB, and the parameters were obtained graphically. The results can offer references for the design of a new erection mechanism based on pyrotechnics.

Angiotensin-converting enzyme 2 (ACE2), angiotensin-(1-7) and Mas receptor in gonadal and reproductive functions.

Angiotensin (Ang)-(1-7) is an active peptide formed from Ang I or Ang-(1-9) by multiple proteolytic steps involving angiotensin-converting enzyme (ACE) 1 and other peptidases, or by a single cleavage of Ang II catalyzed chiefly by ACE2. The effects of Ang-(1-7) are mediated by the G protein-coupled receptor Mas (or Mas1), encoded by the protooncogene MAS. The reproductive system expresses ACE2 quite abundantly and therefore is able to generate Ang-(1-7) using precursor peptides produced locally or taken from circulation. In several mammalian species, Ang-(1-7) stimulates ovarian follicle growth, oocyte maturation and ovulation. The peptide is found in human endometrium, mostly during the secretory phase of menstrual cycle when the uterus is receptive to embryo implantation. Rat models and human observational studies suggest that Ang-(1-7) is part of the maternal adaptive response to pregnancy and its deficiency is associated with poor circulation in the placental bed. Knockout mice revealed a relevant participation of Mas-mediated stimulus to the maintenance of normal spermatogenesis, even though the animal can still reproduce without it. In addition, the vasorelaxant effect of Ang-(1-7) participates in the physiological mechanism of corpus cavernosum blood influx and penile erection. We conclude that preclinical evidence encourages the pursuit of treatments for female and male reproductive dysfunctions based on Mas agonists, starting with its natural ligand Ang-(1-7).

A Rare Case of Recurrent Idiopathic Low-flow Priapism that Developed into a High-flow Priapism

Priapism, according to the American Urological Association is defined as a persistent penile erection that continues hours beyond sexual stimulation; typically, greater than 4 hours. Although priapism is a rare condition and has an unpredictable course in most presentation, it affects 5.36 per 100,000 male subjects per year [1]. Priapism is a urological emergency and delay in treatment or refractory cases can result in cavernous smooth muscle necrosis, fibrosis and penile shortening [2]. There are 2 categories of priapism-namely low-flow (ischemia, veno-occlusive) and high-flow (non-ischemic, arterial) [3,4]. There is a subset of ischemic priapism known as stuttering priapism which presents with recurrent incidences of ischemic priapism varying in length and is usually self-limiting [4]. Low-flow priapism occurs when an occlusive process inhibits the relaxation of the corpus cavernosum, thus the outflow of blood is impaired. The conditions associated with low-flow/ischemic priapism are as follows: sickle cell disease, vasoactive drugs, neoplastic diseases of the penis, urethra, prostate, bladder, kidney, gastrointestinal tract, leukemia, polycythemia, traumatic injury, hyperlipidemic parenteral nutrition, hemodialysis, heparin treatment, Fabry disease and neurologic conditions [3]. On the other hand, high-flow priapism occurs when there is increased arterial blood flow or pooling of blood. Conditions associated with high-flow priapism include traumatic arterio-cavernous fistula, vasoactive drugs, penile revascularization surgery, and neurologic conditions [3]. The mechanism of penile erection is a multifocal phenomenon that involves the nervous system, molecules (nitric oxide, cGMP, calcium), enzymes, and blood vessels. We present an interesting case of a patient with a history of recurrent priapism who converted from a low-flow priapism to a high-flow priapism, thought to be secondary to an arterio-cavernous fistula. Upon further review of PubMed and NIH database, there has been only few of such cases reported. We discuss the diagnostic process and management of high-flow priapism in this report.

Linear Active Disturbance Rejection Control for Lever-Type Electric Erection System Based on Approximate Model

Linear active disturbance rejection control (LADRC) algorithm is proposed to realize accurate trajectory tracking for the lever-type electric erection system. By means of system identification and curve fitting, the approximate model is built, which is consisting of the servo drive system with velocity closed-loop and the lever-type erection mechanism. The proportional control law with velocity feedforward is designed to improve the trajectory tracking performance. The experimental results verify that, based on approximate model, LADRC has better tracking accuracy and stronger robustness to the disturbance caused by the change of intrinsic parameters compared with PI controller.

Improved Linear Active Disturbance Rejection Control for Lever-Type Electric Erection System with Varying Loads and Low-Resolution Encoder

The lever-type electric erection system is a novel kind of erection system and the experimental platform in this paper operates with varying loads and low-resolution encoder. For high accuracy trajectory tracking, linear active disturbance rejection control (LADRC) is introduced. An approximate model, consisting of the servo system configured at velocity control mode and the lever-type erection mechanism, is built by means of system identification and curve fitting. Reduced-order LADRC based on the further simplified model is proposed to improve tracking accuracy and robustness. As comparisons, traditional LADRC and PID with high-gain tracking differentiator (HGTD) are designed. Simulation and experimental results indicate that reduced-order LADRC can realize higher trajectory tracking accuracy with low-resolution encoder and has better robustness to variation in erection loads, compared with traditional LADRC and PID with HGTD.

The Role of Nocturnal Penile Tumescence and Rigidity (NPTR) Monitoring in the Diagnosis of Psychogenic Erectile Dysfunction: A Review.

Nocturnal penile tumescence and rigidity (NPTR) monitoring with RigiScan was considered one of the most reliable methods to differentiate psychogenic erectile dysfunction (pED) from organic ED. However, its reliability has been questioned because of some limitations in the practice. To present contemporary views on the role of NPTR monitoring in the diagnosis of pED. We performed a comprehensive review of English-language literature on NPTR and pED by a PubMed search. Studies were included if the mechanisms of pED and nocturnal erection and the practice of NPTR monitoring in ED were the main research contents. The pED results from not only psychosocial factors but also physiological changes containing central nervous abnormality. NPTR monitoring with RigiScan is still considered a useful method for the diagnosis of pED. A normal NPTR recording in a man with ED complaints probably suggests pED, whereas an abnormal recording may represent organic ED. Radial rigidity of no more than 60% is correlated well with axial rigidity, but, when it is more than 60%, the correlation between them is questioned. The consistency between NPTR and sex-stimulated erection is questionable, and the correlation of NPTR with different patient-reported outcome scoring systems is different. A normal NPTR recording in patients with ED does not necessarily mean pED, especially in patients with spinal cord injury. NPTR recordings can be influenced by depression, smoking, aging, negative dream content, and sleep disorders. NPTR monitoring with the RigiScan is still considered a useful diagnostic tool for pED at the present stage. However, there are some disputes regarding the correlation between penile radial rigidity and axial rigidity and between NPTR and sex-related erection, as well as normative evaluation criteria for ED and the possibility of a false NPTR result, that need to be further studied. Zou Z, Lin H, Zhang Y, etal. The Role of Nocturnal Penile Tumescence and Rigidity (NPTR) Monitoring in the Diagnosis of Psychogenic Erectile Dysfunction: A Review. Sex Med Rev 2019;7:442-454.

Возможности применения ударно-волновой терапии в комплексной коррекции сексуальных дисфункций у женщин

In recent decades, interest in the quality of sexual life has significantly increased all over the world, not only among men but also among women, especially in low-birth-rate European countries. Improving this quality will not only resolve health issues in men and women, but will also improve the demographic situation in these countries. Scientific research in the field of both male and female sexual dysfunction is developing at a rapid pace. Both men and women go through the same phases of sexual reactions cycle: sexual desire, sexual arousal, and, as a result, orgasm and resolution phase. During the phase of sexual arousal, in both men and women, the blood flow to pelvic organs increases, but in the event of erectile dysfunction in men and frigidity in women, this process weakens or does not occur at all. Furthermore, the innervation of genital organs in male and female organisms is identical. Activation, which enables genital innervation, launches the activation of blood circulation in the target organs. Therefore, in case of ED in men, and in case of female sexual arousal disorder in women, along with other specific treatment methods, it is useful to perform non-invasive stimulation of insufficiently active physiological mechanisms of sexual arousal. However, for the treatment of ED in men, such stimulation has already been successfully used for a long time – that is the low-intensity extracorporeal shock wave therapy, which allows to restore the erection mechanism itself. Studies from throughout the world, including those conducted by Ukrainian scientists, have established that low-intensity extracorporeal shock wave therapy induces neovascularization and therefore improves blood circulation. The intensity of the basal and sexually stimulated genital blood flow is a necessary physiological tool of sexual arousal and orgasmic discharge, which makes the subject of artificial stimulation of this indicator by means of shock wave therapy in both men and women particularly important. The use of shock wave therapy can have a number of advantages not only due to the increased blood and lymph flow in the genitals, but also due to the powerful stimulation of the release of neurotransmitters and hormones which provide emotional coloring to the sexual feeling and increase libido (serotonin, dopamine, endorphins etc.). Therefore, along with combined therapy, the method of low-intensity extracorporeal shock wave therapy can be successfully used in the treatment of female sexual dysfunction. Key words: shock wave therapy, sexual dysfunction, female sexual arousal disorder, erectile dysfunction, DSM-5.

162 Dysregulated NO Signaling in the Lower Genitourinary Tract: A Common Mechanism of Erection and Micturition Dysfunction in a Mouse Model of Sickle Cell Disease

Sickle cell disease (SCD) is a state of chronic nitric oxide (NO) deficiency. Priapism, a disorder of non-willful, excessive penile erection, is a highly prevalent complication of SCD. The principal molecular defects underlying priapism in SCD include reduced NO/cGMP/PDE5 bioavailability in the penis related to decreased endothelial NO synthase (eNOS) activity. Recently, urinary dysfunction, including nocturnal enuresis and overactive bladder, have been clinically observed in SCD patients, but the mechanisms underlying urinary dysfunction in SCD are unknown. We hypothesized that aberration in NO regulatory signaling is a common pathophysiologic mechanism for concomitant erection and voiding disorders in SCD. 3 month old SCD (Sickle) and wild type (WT) male mice were used. Erectile function measurement (intracavernosal pressure/mean arterial pressure) and cystometric studies were performed. Bladder and urethra were collected from separate groups of Sickle and WT mice for organ bath studies or measurement of protein expressions of phospho (P)-eNOS (Ser-1177) and P-nNOS (Ser-1412) protein expression by Western immunoblot.

Topology Optimisation and Fabrication Aspects for Light Weight Design of an Articulating Beam of Article Launching System

<p class="p1">Light weight design of an articulating beam that is utilised for erection mechanism of heavy article (above 15-ton class) is quite challenging task considering high stiffness requirement at erection start mode. The research work presents structural topology optimisation of an articulating beam to obtain optimal material distribution within available space pertaining to required stiffness parameters and boundary constrains. Optimal weight of articulating beam structure is achieved using density optimisation technique aiming minimum compliance and volume. This study highlights problem formulation with solid isotropic material with penalisation optimisation technique with case study followed by discussion on various fabrication aspects for converting the topology results in to feasible design. As an outcome, optimal material design of the articulated beam is achieved that is converted into two feasible light weight designs considering manufacturing aspects. These designs are then validated for their structural adequacy with finite element analysis computing desired stiffness and strength parameters.<span class="Apple-converted-space"> </span></p>

Efficacité de la rééducation du plancher pelvien dans la dysfonction érectile : revue de la littérature

The pelvic floor is now well known and its role in the mechanism of erection is demonstrated. We wanted to know what is the evidence of the effectiveness of perineal rehabilitation in erectile dysfunction. An English search was performed in Google scholar and databases PubMed, Medline, Pedro with the keywords "pelvic floor, erectile dysfunction, impotence, physiotherapy, exercises, rehabilitation, PFMT". We have selected randomized clinical trials published in indexed journals. Six randomized trials were selected. Five of them have shown statistically and clinically significant effectiveness in populations of men with erectile dysfunction and various underlying pathologies. In the fifth trial, the difference in effectiveness was not statistically significant. At 3months, the best-conducted study showed an average improvement of 7points at IIEF-5compared to the control group (P-value: 0.004). Rehabilitation has not resulted in any adverse side effects. However, these studies were conducted in heterogeneous populations and the protocols for pelvic floor muscle strengthening rehabilitation differed from one study to another, making it impossible to formulate a specific recommendation for clinical practice. Based on the results of this literature review, perineal physiotherapy may have a role to play in the management of erectile dysfunction.

Fuzzy sliding mode control for erection mechanism with unmodelled dynamics

ABSTRACTErection mechanism is a complicated system suffering from nonlinearities, uncertainties and disturbances. It is difficult to establish mathematical model and perform a high precision control using linear control methods. In this study, adaptive fuzzy sliding mode control algorithm was designed to control erection mechanism. The proposed method combines the advantages of fuzzy logic and sliding mode control. The structure of the system is partially unknown and does not require the bounds of uncertainty to be known. Fuzzy logic is used to approximate the unknown parts of the system. The chattering phenomenon of sliding mode control is eliminated without deteriorating the system robustness. Experimental results of the position control under various reference trajectories are obtained. The proposed method can achieve favourable tracking performance for erection mechanism in the presence of unmodelled dynamics and disturbances.

Mathematical Modeling and Fuzzy Adaptive PID Control of Erection Mechanism

This paper describes an application of fuzzy adaptive PID controller to erection mechanism. Mathematical model of erection mechanism was derived. Erection mechanism is driven by electro-hydraulic actuator system which is difficult to control due to its nonlinearity and complexity. Therefore fuzzy adaptive PID controller was applied to control the system. Simulation was performed in Simulink software and experiment was accomplished on laboratory equipment. Simulation and experiment results of erection angle controlled by fuzzy logic, PID and fuzzy adaptive PID controllers were respectively obtained. The results show that fuzzy adaptive PID controller can effectively achieve the best performance for erection mechanism in comparison with fuzzy logic and PID controllers.

Mathematical Modeling and Fuzzy Adaptive PID Control of Erection Mechanism

Mathematical Modeling and Fuzzy Adaptive PID Control of Erection Mechanism

Erectile Dysfunction: Science and Medicine

Abstract Much progress has been made over the past 20 years in the science and medicine of erectile dysfunction. Advances in knowledge of the basic mechanisms of penile erection and that associated with its pathophysiology have been impressively translated into an expanding range of therapies, which have increasingly enabled natural erectile responses. Despite this progress, ideal interventions for erectile dysfunction should fully restore natural erectile ability without the need for repeated treatments. Progress in the field is expected to address this limitation and to arise from new discoveries of erectile mechanisms and novel approaches to deliver corrective therapy.

MP76-04 ANDROGENIC THERAPY IN TREATING PATIENTS WITH VASCULOGENIC ERECTILE DYSFUNCTION

You have accessJournal of UrologySexual Function/Dysfunction: Medical, Hormonal & Non-surgical Therapy I1 Apr 2016MP76-04 ANDROGENIC THERAPY IN TREATING PATIENTS WITH VASCULOGENIC ERECTILE DYSFUNCTION Dmitry Kurbatov, Andrey Erkovich, Roman Aliev, and Ruslan Aliev Dmitry KurbatovDmitry Kurbatov More articles by this author , Andrey ErkovichAndrey Erkovich More articles by this author , Roman AlievRoman Aliev More articles by this author , and Ruslan AlievRuslan Aliev More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.1855AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES It is well known that testosterone plays a critical role in regulation of erectile function (EF). Veno-occlusive insufficiency is a causal or accompanying symptom in 20–45% of patients with ED. The conventional therapy of venogenic ED may be useless if unrecognized andogendeficiency. There are limited data shown that testosterone improves EF in hypogonadal patients with veno-occlusive dysfunction. In this multiclinical study we evaluated the results of testosterone therapy (TT) in the hypogonadal patients with corporal venous leakage. METHODS 49 hypogonadal men with ED and venous leakage from corpora cavernosa, aged 32 – 56 (44±8, 3) non-responded to PDE-5 inhibitors, were examined. Comorbidities included diabetes mellitus (4 pts), arterial hypertension (5 pts), alcohol abuse ( 8pts). Testosterone levels were 2,3 -11,2 (6,8±3,1) nmol/l. After lab tests each patient underwent penile duplex ultrasound for reveling signs of venous deficiency. Arterial inflow was normal at all patients while the end diastolic velocity was >5 ml/sec. All patients underwent the treatment with 1,000 mg testosterone undecanoate on day 1, followed by another injection after 6 weeks and every 3 months thereafter - 5 injections totally. Pharmacocavernosography (PCG) (7 pts) or magnetic resonance imaging (MRI) with contrast enhancement (14 pts) were used for visualization of venous leakage pathways prior to TT and after 6 -8 months of TT for the detection of venous leakage decreasing. Design of the investigation: open, prospective, non-control, non-randomize. RESULTS All patients responded to the therapy and noted the considerable improvement in EF domain (IIEF scores increased to 24,5 ± 0,5) and SD domain (IIEF scores increased to 9 ± 0.3) 41/49 pts (84%) restore satisfactory coitus with monotherapy of testosterone. 8/49 pts (16%) poor responded to monotherapy had satisfactory coitus after combine therapy with PDE-5 inhibitors. After 6 months treatment the control penile duplex ultrasound revealed in 45 pts the end diastolic velocity <5 ml/sec. PCG or MRI was repeated in 12 patients. Compared with baseline investigation, repeat radiological studies after TT showed significant decreasing or even absence of the venous leakage from the corporal bodies. CONCLUSIONS These results demonstrate that testosterone regulates the veno-occlusive mechanism of erection and improves the EF in hypogonadal patients with venous leakage. The combination of TT with PDE-5 inhibitors will be useful in poor responders to the testosterone monotherapy. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e1008 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Dmitry Kurbatov More articles by this author Andrey Erkovich More articles by this author Roman Aliev More articles by this author Ruslan Aliev More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Architecture of the Corpus Spongiosum: An Anatomical Study

Urethral reconstruction is performed for urethral stricture or hypospadias correction. Research on urethral tissue engineering is increasing. Because the corpus spongiosum is important to support the urethra, urethral tissue engineering should ideally be combined with reconstruction of a corpus spongiosum. We describe a method to visualize and measure the architecture of the corpus spongiosum, which is needed for scaffold design. The penis was dissected from 2 unembalmed male cadavers. One penis was flaccid and the other was erect, as induced by saline infusion. Both were frozen in ice. At 6 sites sections were obtained in the transverse and frontal directions. After digitalizing the stained sections the images were edited, area measurements were taken and a 3-dimensional reconstruction was made. In transverse sections the mean area of the vascular lumen was 60% and 77% in the flaccid and the erect corpus spongiosum, and in frontal sections it was 53% and 74%, respectively. This indicated a 129% transverse increase and a 140% longitudinal increase in erection. Section sites did not essentially differ except in the glans penis. Frontal sections showed larger vascular cavities and more incomplete septae than transverse sections. This study provides what is to our knowledge novel information on corpus spongiosum architecture, which is relevant for scaffold design in tissue engineering. The study protocol can be used in future research with a larger number of specimens and more extensive analyses.