Sphincter Prosthesis Research Articles

Advances in Assistive Electronic Device Solutions for Urology.

Recent technology advances have led urology to become one of the leading specialities to utilise novel electronic systems to manage urological ailments. Contemporary bladder management strategies such as urinary catheters can provide a solution but leave the user mentally and physically debilitated. The unique properties of modern electronic devices, i.e., flexibility, stretchability, and biocompatibility, have allowed a plethora of new technologies to emerge. Many novel electronic device solutions in urology have been developed for treating impaired bladder disorders. These disorders include overactive bladder (OAB), underactive bladder (UAB) and other-urinary-affecting disorders (OUAD). This paper reviews common causes and conservative treatment strategies for OAB, UAB and OUAD, discussing the challenges and drawbacks of such treatments. Subsequently, this paper gives insight into clinically approved and research-based electronic advances in urology. Advances in this area cover bladder-stimulation and -monitoring devices, robot-assistive surgery, and bladder and sphincter prosthesis. This study aims to introduce the latest advances in electronic solutions for urology, comparing their advantages and disadvantages, and concluding with open problems for future urological device solutions.

Dual implantation of an artificial urinary sphincter and inflatable penile prosthesis

Dual implantation of an artificial urinary sphincter and inflatable penile prosthesis

68 - Synchronous penoscrotal implantation of penile and artificial urinary sphincter prosthesis after radical prostatectomy: Single institutional experience in 9 years

68 - Synchronous penoscrotal implantation of penile and artificial urinary sphincter prosthesis after radical prostatectomy: Single institutional experience in 9 years

PD21-11 THE DYNAMIC URINE VIBRATION HALTER: A NEW OUTPATIENT DEVICE FOR REMOTE PATIENT MONITORING OF UROFLOW

You have accessJournal of UrologyTechnology & Instruments: Laparoscopy and Robotics: Benign Disease1 Apr 2015PD21-11 THE DYNAMIC URINE VIBRATION HALTER: A NEW OUTPATIENT DEVICE FOR REMOTE PATIENT MONITORING OF UROFLOW Jerry Blaivas, Matthew Benedon, James Weinberger, Yosi Rozenberg, Lior Ravid, and Jonathan Vapnek Jerry BlaivasJerry Blaivas More articles by this author , Matthew BenedonMatthew Benedon More articles by this author , James WeinbergerJames Weinberger More articles by this author , Yosi RozenbergYosi Rozenberg More articles by this author , Lior RavidLior Ravid More articles by this author , and Jonathan VapnekJonathan Vapnek More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.1440AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES The aim of the study is to compare uroflow parameters measured by a standard gravimetric uroflowmeter (GF) with the Dynamic Urine Vibration Halter (DUVH). METHODS The DUVH measures flow characteristics inside the urethra. A removable, small, vibro-acoustic sensor connected to a portable recorder is placed on the dorsum of the penis. Vibratory data during voiding is captured, stored, analysed by algorithms, and displayed. A prospective IRB approved study was conducted at two outpatient urology centers. Consecutive men were recruited. Subjects were instructed to urinate into GF while wearing the DUVH. Uroflow parameters recorded by the DUVH (voided volume [VV], maximum flow rate [Qmax], voiding time, flow time, average flow rate [Qavg]) were compared with the gravimetric flows using Pearson's Correlation Coefficient (Pearson's r). Exclusion criteria included inability to void, penile or sphincter prosthesis & improper use of the device. RESULTS 73 patients were recruited of whom 6 were excluded - 1 was unable to void. One had an intermittent stream that was not captured on the GF (the DUVH recognized all segments). In four patients, the DUVH recording was technically flawed. The measured parameters were equivalent between the two devices (table 1). Figure 1 shows representative tracings and figure 2 shows comparison of the two devices. The quantitative measures showed excellent correlation, but as seen in fig 2, there were 6 uroflow outliers, 4 of whom had a poor signal on the DUVH. There was a difference in Qmax of <3 ml/s in 79% (53/67). CONCLUSIONS The DUVH is a promising new technology for remote patient monitoring of uroflow. Further work needs to be done to increase the accuracy of this tool. Table 1. Comparison of measured parameters: DUVH vs. GF Qmax (ml/s) VV (ml) Qavg (ml/s) Voiding Time (s) Flow Time (s) DUVH 11.5±5.7 213.1±134.8 6.5±3.5 39.3±22.3 33.1±15.2 GF 11.8±5.8 216.7±132.8 6.2±3.2 46.0±29.8 35.2±18.9 Pearson’s r 0.87 0.92 0.81 0.70 0.78 p-value 0.74 0.88 0.71 0.14 0.48 © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e475 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Jerry Blaivas More articles by this author Matthew Benedon More articles by this author James Weinberger More articles by this author Yosi Rozenberg More articles by this author Lior Ravid More articles by this author Jonathan Vapnek More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Design and evaluation of an intelligent artificial anal sphincter system powered by an adaptive transcutaneous energy transfer system.

The aim of this study was to optimize an intelligent artificial anal sphincter system (AASS) II for patients with severe fecal incontinence. Redesigning and integrating a pressure sensor into the sphincter prosthesis allows us to reduce the sensor volume and makes it suitable for a chronic, ambulatory application. Furthermore, a close-loop frequency control method was designed for the transcutaneous energy transfer system. Finally, a longer working time of the implanted device was obtained by the low-power design of the hardware and software. The new model was implanted in 2 dogs and studied for periods of up to 5 weeks. The output voltage induced on the load of 30 Ω, for a variation range in k of 0.12 ~ 0.42, was maintained at approximately 6.8 V with a frequency control range of the 270 ~ 320 kHz. The minimum and maximum output voltages of the pressure sensor were found to be 1.7 V and 2.34 V, respectively, which corresponded to a pressure range of 90 ~ 120 kPa with maximum change rate of approximately 3.7% caused by the temperature variations. Moreover, compared with AASS I, the low-power design resulting in 94% reduction in power consumption. The efficacy of the device in achieving continence and sensing the need to defecate was assessed in an animal model. The technical concept and the design of the AASS II turned out to be capable of fulfilling the medical requirements.

Surgery for male urinary incontinence: where are we now and what is in the pipeline?

Male stress urinary incontinence, which has radical prostatectomy as the main aetiology, affects about 39% of the adult male population and is one of the complications of radical prostatectomy with the greatest impact on the quality of life of patients. There are a wide range of treatments for stress urinary incontinence available to the urologist, ranging from conservative treatments to surgical treatments, from minimally invasive procedures to the implant of artificial sphincter prosthesis. The aim of this work is to define the state-of-the-art of surgical treatments for male stress urinary incontinence, analyzing the most recent studies in the literature and evaluating the available scientific evidence.

C85: Preliminary own experiences in implantation artificial urinary sphincter and penile prosthesis in patients after radical prostatectomy

C85: Preliminary own experiences in implantation artificial urinary sphincter and penile prosthesis in patients after radical prostatectomy

Design and simulation of advanced charge recovery piezoactuator drivers

The German Artificial Sphincter System project aims at the development of an implantable sphincter prosthesis driven by a piezoelectrically actuated micropump. The system has been designed to be fully implantable, i.e. the power supply is provided by a rechargeable lithium polymer battery. In order to provide sufficient battery duration and to limit battery dimensions, special effort has to be made to minimize power consumption of the whole system and, in particular, of the piezoactuator driver circuitry. Inductive charge recovery can be used to recover part of the charge stored within the actuator. We are going to present a simplified inductor-based circuit capable of voltage inversion across the actuator without the need of an additional negative voltage source. The dimension of the inductors required for such a concept is nevertheless significant. We therefore present a novel alternative concept, called direct switching, where the equivalent capacitance of the actuator is charged directly by a step-up converter and discharged by a step-down converter. We achieved superior performance compared to a simple inductor-based driver with the advantage of using small-size chip inductors. As a term of comparison, the performance of the aforementioned drivers is compared to a conventional driver that does not implement any charge recovery technique. With our design we have been able to achieve more than 50% reduction in power consumption compared to the simplest conventional driver. The new direct switching driver performs 15% better than an inductor-based driver. A novel, whole-system SPICE simulation is presented, where both the driving circuit and the piezoactuator are modeled making use of advanced nonlinear models. Such a simulation is a precious tool to design and optimize piezoactuator drivers.

The First Teleautomatic Low‐Voltage Prosthesis With Multiple Therapeutic Applications: A New Version of the German Artificial Sphincter System

To date, there are no artificial sphincter prostheses for urinary or fecal incontinence that may be implemented elsewhere instead, for example, in the upper gastrointestinal tract. Conventional systems are conceptually similar but are constructed specifically for distinct applications and are manual in operation. The German Artificial Sphincter System (GASS) II is the evolution of a highly integrative, modular, telemetric sphincter prosthesis with more than one application. Redesigning and integrating multilayer actuators into the pump allows us to reduce the input voltage to -10 to +20 V (V(PP) = 30 V). This provides for a flow rate of 2.23 mL/min and a counterpressure stability of 260 mbar. Furthermore, multiple applications have become feasible due to our standardized connection system, therapy-specific compression units, and application-specific software. These innovations allow us to integrate not only severe fecal and urinary incontinence, erectile dysfunction, and therapy-resistant reflux disease, but also morbid adiposity into the gamut of therapeutic GASS applications.

Patient Satisfaction After Dual Implantation of Inflatable Penile and Artificial Urinary Sphincter Prostheses

Since description of the transverse scrotal approach for artificial urinary sphincter (AUS) placement, simultaneous implantation of an inflatable penile prosthesis (IPP) and AUS through a single incision has been shown to constitute safe, efficient, and cost-effective treatment for men plagued by both erectile dysfunction and urinary incontinence. We present patient satisfaction outcomes after simultaneous dual implantation (DI) of an IPP and AUS. We compared outcomes of postprostatectomy patients who underwent DI to those receiving IPP or AUS alone from 2001 to 2006. Telephone interviews using a standard questionnaire were conducted to evaluate prosthetic functionality, ease of use, and patient satisfaction. A total of 95 men were evaluated (31 for IPP alone, 31 for AUS alone, and 33 for DI). Daily pad usage decreased from 4.6 to 0.8 pads per day with AUS alone and 6.1 to 1.3 pads per day with DI. Patients were similarly satisfied with IPP rigidity during inflation and flaccidity during inactivation in both IPP and DI groups (4.1 to 4.4 for rigidity and 3.9 for flaccidity [1 = "unhappy" and 5 = "happy"]). Ease of scrotal pump operation was similar in all groups, as was overall prosthetic satisfaction. Most patients stated that they would recommend the DI procedure to a friend or relative (87% to 94%) or have the procedure done again (77% to 94%). Dual implantation produces encouraging outcomes in patient satisfaction, ease of use and functionality that are similar to those found after placement of either IPP or AUS alone.

MEMS-based micropumps in drug delivery and biomedical applications

This paper briefly overviews progress on the development of MEMS-based micropumps and their applications in drug delivery and other biomedical applications such as micrototal analysis systems (μTAS) or lab-on-a-chip and point of care testing systems (POCT). The focus of the review is to present key features of micropumps such as actuation methods, working principles, construction, fabrication methods, performance parameters and their medical applications. Micropumps have been categorized as mechanical or non-mechanical based on the method by which actuation energy is obtained to drive fluid flow. The survey attempts to provide a comprehensive reference for researchers working on design and development of MEMS-based micropumps and a source for those outside the field who wish to select the best available micropump for a specific drug delivery or biomedical application. Micropumps for transdermal insulin delivery, artificial sphincter prosthesis, antithrombogenic micropumps for blood transportation, micropump for injection of glucose for diabetes patients and administration of neurotransmitters to neurons and micropumps for chemical and biological sensing have been reported. Various performance parameters such as flow rate, pressure generated and size of the micropump have been compared to facilitate selection of appropriate micropump for a particular application. Electrowetting, electrochemical and ion conductive polymer film (ICPF) actuator micropumps appear to be the most promising ones which provide adequate flow rates at very low applied voltage. Electroosmotic micropumps consume high voltages but exhibit high pressures and are intended for applications where compactness in terms of small size is required along with high-pressure generation. Bimetallic and electrostatic micropumps are smaller in size but exhibit high self-pumping frequency and further research on their design could improve their performance. Micropumps based on piezoelectric actuation require relatively high-applied voltage but exhibit high flow rates and have grown to be the dominant type of micropumps in drug delivery systems and other biomedical applications. Although a lot of progress has been made in micropump research and performance of micropumps has been continuously increasing, there is still a need to incorporate various categories of micropumps in practical drug delivery and biomedical devices and this will continue to provide a substantial stimulus for micropump research and development in future.

A novel artificial sphincter prosthesis driven by a four-membrane silicon micropump

In this paper we present the state of the art of our artificial sphincter project. A novel silicon micropump has been designed recently for this system that features a four-membrane actuator set-up. The four-membrane micropump can transport fluid bidirectional with a maximum flow rate of 4.1 ml/min and can build up a back pressure of 60 kPa. The total size of the micropump is 30 mm × 12 mm × 1 mm. The novel pump is modeled by a lumped-parameter approach and compared to our three-membrane design. The main advantage of an additional membrane is a reduction of the driving frequency of the micropump while the flow rate remains the same compared to a three-membrane model. Consequently, the power consumption of the micropump can be reduced. A reliability analysis shows that the four-membrane micropump is more reliable then our previous design. The micropump was integrated into the artificial sphincter prosthesis. The first in vivo experiment is described and the measured data of the prosthesis implanted in a mini pig are given.

German Artificial Sphincter System: First Report of a Novel and Highly Integrated Sphincter Prosthesis for Therapy of Major Fecal Incontinence

German Artificial Sphincter System: First Report of a Novel and Highly Integrated Sphincter Prosthesis for Therapy of Major Fecal Incontinence

German Artificial Sphincter System-GASS

No highly integrated sphincter prosthesis for therapy of major fecal incontinence exists. Therefore, we developed a novel neosphincter, made of polyurethane. The GASS consists of a support ring (SR) which includes a fluid reservoir, fixed on the outer diameter of the SR, and a multi-chamber occluding cuff (C(int)) on the inside diameter. The total inflation volume of C(int) is about 23 cc. The integrated micropump based on piezotechnology measures 30x13x1 mm3 (flowrate 1.4 cc/min, max. backpressure 40,000 Pa) . GASS was evaluated around the external sphincter of isolated porcine anal canals. The threshold of continence was defined as the inflating volume which water ceased to leak through the area occluded by C(int) under an induced rectal pressure of 150 cm H2O. Minimal filling volumes maintained continence for liquids against high luminal pressures. A low intraanal resting pressure (delta p(anal)) induced by activated GASS indicates a little risk of ischemic injury of the anal canal in vivo (median delta p(anal) 24.1 mm hg:15 cc vs 46.9 mm hg:21 cc). In summary, a highly integrated and efficient high-tech neosphincter for the therapy of major fecal incontinence could be realized.

Intraurethral sphincter prosthesis to treat hyporeflexic bladders in women: does it work?

To assess the efficacy and safety of a new intraurethral sphincter prosthesis to treat hyporeflexic bladders in women. Between July 1997 and December 1998, 18 women (mean age 45.8 years, range 26-84) with neurogenic voiding disorders and a hyporeflexic bladder were examined prospectively. All but one patient (who used the Crédé manoeuvre) emptied their bladder using clean intermittent catheterization. The women were fitted with a prosthesis consisting of a valve and a pump inside a short self-retaining silicone device, which was activated by a magnetic remote control unit. The evaluation before implantation comprised a medical history, a neurological evaluation, urodynamic recordings and urine cultures. The follow-up after implantation included a monthly clinical assessment, a symptom questionnaire, urine culture, ultrasonographic examinations and replacement of the device if necessary. Urine samples were also cultured if there was any discomfort or fever. At 16 months of follow-up, only six of 18 patients continued to use the implant (mean follow-up 9.6 months) and were satisfied. In 10 patients major incontinence around the catheter, or irritation, led to removal of the device. Two patients were unable to learn how to transfer to the toilet to empty their bladder; therefore, their implant was removed and they were treated with a suprapubic catheter. Two patients died from unrelated causes. Twelve patients had positive bacteriuria while fitted with the device; six of them became symptomatic. Usually, only symptomatic lower urinary tract infections were treated. Technical problems occurred often; 14 catheters showed technical dysfunction and had to be replaced early and three external remote control units broke for no reason. Despite normal short-term cystoscopic findings (three patients), long-term urethral damage cannot be excluded. Indeed, the six patients who remain fitted with the device already show some widening of their urethra. This experience with the new device was disappointing; in eight of the 18 patients incontinence appeared or worsened and led to removal of the device. Technical problems were common. The other concern is that significant long-term urethral damage could be expected, as observed with indwelling catheters over time. Thus, although this device may function for a short period, it is unsuitable for long-term use.

ARTIFICIAL URINARY SPHINCTER FOR POST-RADICAL PROSTATECTOMY URINARY INCONTINENCE: LONG-TERM SUBJECTIVE RESULTS

Incontinence affects between 3% and 60% of patients after radical prostatectomy. Insertion of an artificial urinary sphincter is a mainstay therapeutic option available to these patients. We assessed patient satisfaction, outcome and complications long after artificial urinary sphincter implantation. From a data bank of 131 patients who underwent artificial urinary sphincter prosthesis insertion we identified 71 with a mean age of 72 years who had also undergone radical prostatectomy and were available for evaluation. This group included 29 patients (40.8%) who received an earlier version of the AMS-800 (American Medical Systems, Minnetonka, Minnesota) and 42 (59.2%) who received the newer narrow back cuff device. Information on surgical procedures and followup were obtained from a computerized database. Patients were also contacted by an impartial reviewer who administered a standard telephone questionnaire on the degree of continence, complications, other means used to help with urinary continence, proficiency in device operation and satisfaction. At a mean followup of 7.7 years (range 0.5 to 16) 19 patients (27%) used 0, 23 (32%) used 1, 11 (15%) used 1 to 3 and 18 (25%) used more than 3 daily, while 1 used an external catheter. Surgical revision in 21 cases (29%) was required due to mechanical failure in 18 (25%), device erosion in 3 (4%) and infection in 1 (1.4%). The need for revision correlated significantly with the design of the sphincter (p = 0.005). Only 7 of the 42 patients in whom a narrow cuff AMS-800 was implanted needed revision versus 18 of the 23 with a previous design. Mean time to revision was 2.5 years (range 0.5 to 8). The device was removed in 2 cases (2.8%). Of the patients 41 (58%) are very satisfied, 14 (19%) are satisfied and 16 (23%) are unsatisfied with the device. The degree of satisfaction correlated with the number of pads used (p = 0.0005) and sphincter design (0.028) but not with the number of surgical revisions (p = 0.521) or patient age. The artificial urinary sphincter is a viable treatment option for post-radical prostatectomy incontinence with a high rate of continence and satisfaction for a long period after the procedure. Patients should be informed that complications necessitating device revision and explantation may appear late in followup. A standard definition of treatment success and studies of homogenous groups of patients with an artificial urinary sphincter would enable better understanding and patient education in the future.

A New Intraurethral Sphincter Prosthesis With a Self Contained Urinary Pump

An intraurethral sphincter prosthesis with a self contained urinary pump for the management of atonic bladder in women was developed and tested. The prosthesis is comprised of a short, self retaining silicone catheter in which there is a valve and pump. Available in a range of lengths and diameters according to urethral size, its insertion is similar to that of a urethral catheter. The prosthesis is secured by a novel fixation method that has soft expandable silicone fins at the bladder neck and a flexible flange at the external meatus. It is activated by a small hand-held control device. To urinate, the activator is placed on the lower abdomen area and the "on" button is pressed, providing energy to the pump by a magnetic coupling method. Once activated, the valve opens and the pump rotates at a high speed, drawing urine from the bladder and pushing it forward, allowing the patient to "void" with a urine flow of 10 to 12 cc/sec. When the bladder is completely evacuated, the pumping ceases and the valve closes, restoring continence. The device was evaluated clinically in 17 women. Fifteen of the patients had a range of use of 2 weeks to 16 months during which they were dry and had complete bladder emptying. Two patients did not tolerate the device because of uninhibited detrusor contractions and, in both cases, it was removed without complication after 5 days.

A New Intraurethral Sphincter Prosthesis With a Self Contained Urinary Pump

A New Intraurethral Sphincter Prosthesis With a Self Contained Urinary Pump

Biomechanical evaluation of an artificial anal sphincter prosthesis

An artificial anal sphincter was designed to reproduce the normal physiology of the ano-rectum by flattening and angulating the bowel without causing crenation. It was shown in the laboratory that by eliminating crenation, occlusion pressure was evenly distributed without localized high pressure points under the device. Further, the design facilitates the creation of angulation of the bowel in a relatively large area of distribution of the occlusion pressure, allowing the device to be set at lower operating occlusion pressures than that required for circular designs yet still achieve continence. Each of the components of the device was studied separately and the whole system was assessed in an acute and survival animal model.

Urinary incontinence after radical prostatectomy

Urinary incontinence after radical prostatectomy is common, but in most patients the symptoms are transitory and subside spontaneously within several days to several months. During the recovery period, suitable means of managing the incontinence must be devised. These include absorbent pads, penile clamps, condom catheters, and occasionally indwelling catheters. Even at this early stage, it is important to exclude two remediable conditions-urinary tract infection and urinary retention. For the 5-10% of patients with persistent incontinence, the diagnosis and treatment is more difficult than a review of the literature might suggest and requires a complete evaluation, including micturition diaries and pad tests, urodynamics (including detrusor pressure/uroflow studies), and cystoscopy. The causes of postprostatectomy incontinence include sphincter malfunction, detrusor abnormalities, and urinary retention with overflow. Detrusor abnormalities include involuntary detrusor contractions, impaired or absent detrusor contractility, and low bladder compliance. Involuntary detrusor contractions may be caused by urinary tract infection, bladder outlet obstruction, bladder stones, carcinoma of the bladder, retained sutures or other foreign bodies, and neurologic conditions. Treatment of involuntary detrusor contractions includes (1) alleviating the underlying cause, (2) anticholinergics, (3) behavior modification, (4) biofeedback and (5) electrical stimulation. Most sphincteric incontinence is self-limited. Persistent sphincteric incontinence is usually associated with anastomotic scarring. The only surgical treatment of proven efficacy is sphincter prosthesis, but this should be considered only after about 1 year has elapsed, unless the incontinence is particularly severe and is clearly not improving. Periurethral injections of substances such as collagen show promise, with almost inconsequential morbidity, but are still in an evolutionary mode. Cancer 1995 ;75 :1978-82.