Preclinical development of SMA artificial anal sphincters

Luo, Yun; Higa, Masaru; Amae, Shintaro; Takagi, Toshiyuki; Yambe, Tomoyuki; Okuyama, Takeshi; Tanaka, Hiromu; Kakubari, Yasuyuki; Matsuki, H.

doi:10.1080/13645700600836695

Cited by 16 publications

(9 citation statements)

References 18 publications

(19 reference statements)

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“…A series of one to three months studies with goats was performed to test safety and efficacy of the pre-clinical prototype. 31 The authors had not detected any sign for infection around the implant but found a 3 to 5 mm-thick fibrous capsule around all components after 13 weeks. This capsule presumably influenced the force acting on the tissue, which was originally set to 5 to 8 kPa, i.e., 40 to 60 mmHg.…”

Section: Current Research On Artificial Sphincter Prosthesesmentioning

confidence: 87%

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Artificial Muscle Devices: Innovations and Prospects for Fecal Incontinence Treatment

et al. 2016

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Fecal incontinence describes the involuntary loss of bowel content, which is responsible for stigmatization and social exclusion. It affects about 45% of retirement home residents and overall more than 12% of the adult population. Severe fecal incontinence can be treated by the implantation of an artificial sphincter. Currently available implants, however, are not part of everyday surgery due to long-term re-operation rates of 95% and definitive explantation rates of 40%. Such figures suggest that the implants fail to reproduce the capabilities of the natural sphincter. This article reviews the artificial sphincters on the market and under development, presents their physical principles of operation and critically analyzes their performance. We highlight the geometrical and mechanical parameters crucial for the design of an artificial fecal sphincter and propose more advanced mechanisms of action for a biomimetic device with sensory feedback. Dielectric electro-active polymer actuators are especially attractive because of their versatility, response time, reaction forces, and energy consumption. The availability of such technology will enable fast pressure adaption comparable to the natural feedback mechanism, so that tissue atrophy and erosion can be avoided while maintaining continence during daily activities.

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Section: Current Research On Artificial Sphincter Prosthesesmentioning

confidence: 87%

“…To avoid thermal damages of the surrounding tissue and to allow healing after the surgery, a hinge mechanism keeps the canal open for the necessary periods of time. 31 …”

Section: Current Research On Artificial Sphincter Prosthesesmentioning

confidence: 99%

Artificial Muscle Devices: Innovations and Prospects for Fecal Incontinence Treatment

et al. 2016

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“…The research team from SEE, SJTU highly integrated all the components with sensor feedback to make surgical implantation easy and at low risk (Zan et al, 2008). Yun Luo developed an AAS device with a reduced number of parts and a compact structure for a less invasive prosthesis (Luo et al, 2006). In preliminary studies, Yun Luo found that the thickness of tissue around the implant was changed dramatically by a stress shielding effect caused by the large mechanical stimulus.…”

Section: Discussionmentioning

confidence: 99%

“…The basic design of the device is to use two elements implanted inside the body: an SMA based artificial sphincter and a secondary coil (Fig. 5) (Luo et al, 2006). Although the dimensions of the artificial sphincter are comparable to those of the silicone cuff in the AMS800, the secondary coil is disk-like and drastically reduces the volume of the implant.…”

Section: Tohoku University Artificial Sphincter Systemmentioning

confidence: 99%

Challenges faced in the clinical application of artificial anal sphincters

Wang

Zhou

Luo

2015

J. Zhejiang Univ. Sci. B

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Abstract:Fecal incontinence is an unresolved problem, which has a serious effect on patients, both physically and psychologically. For patients with severe symptoms, treatment with an artificial anal sphincter could be a potential option to restore continence. Currently, the Acticon Neosphincter is the only device certified by the US Food and Drug Administration. In this paper, the clinical safety and efficacy of the Acticon Neosphincter are evaluated and discussed. Furthermore, some other key studies on artificial anal sphincters are presented and summarized. In particular, this paper highlights that the crucial problem in this technology is to maintain long-term biomechanical compatibility between implants and surrounding tissues. Compatibility is affected by changes in both the morphology and mechanical properties of the tissues surrounding the implants. A new approach for enhancing the long-term biomechanical compatibility of implantable artificial sphincters is proposed based on the use of smart materials.

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“…Thus, stable and implantable PSS is required to supply enough power to AAS. Therefore, some preliminary form of PSSs appear in later AAS like Acticon Neosphincter, PAS, GASS, and artificial sphincter-shape memory alloy (AS-SMA) [17][18][19][20][21][22][23] . Preliminary PSSs bring many advantages to AAS.…”

Section: Introductionmentioning

confidence: 99%

A novel power supply system for puborectalis‐like artificial anal sphincter

et al. 2019

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Puborectalis‐like artificial anal sphincter (PAAS) is an innovative new type of artificial anal sphincter (AAS). It overcomes many drawbacks and inadequacies of various previous AASs, and it has successfully been implanted in vivo for almost 3 weeks. During in vivo testing, PAAS shows its ability to retain continence with low risk of ischemia necrosis, and somehow truly helps to remodel rectal perception. However, there are still many defects that influence the long‐term implantation of PAAS, especially in the power supply system (PSS). This article presents a new designed PSS which includes a new transcutaneous energy transfer (TET) system, a heat reduction system, and a safety usage system. The new PSS reduces the total size of PAAS by at least 30%. Newly designed TET system can satisfy the Qi standard, and render a power of 3W to fulfill the requirement of fast charging and normal use of PAAS at the distance of 15.5 mm when frequency of TET system is 110 kHz, which previous TET systems can hardly achieve. Heat reduction system helps to reduce the heat generated during TET charging. It can reduce heat by 40% during the same period of time of TET charging. Safety usage system helps the user control PAAS more properly which can reduce the rate of failure of PAAS system.

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Preclinical development of SMA artificial anal sphincters

Cited by 16 publications

References 18 publications

Artificial Muscle Devices: Innovations and Prospects for Fecal Incontinence Treatment

Artificial Muscle Devices: Innovations and Prospects for Fecal Incontinence Treatment

Challenges faced in the clinical application of artificial anal sphincters

A novel power supply system for puborectalis‐like artificial anal sphincter

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