• Title/Summary/Keyword: Nerve simulation

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A New Model for Basic Microsurgical Nerve Repair Simulation: Making the Most Out of Less

  • Bogdan Ioncioaia
    • Archives of Plastic Surgery
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    • v.50 no.2
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    • pp.220-221
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    • 2023
  • Microsurgical peripheral nerve repair is a technical and challenging procedure that requires thorough training prior to a real-life operating theater scenario. While the gold standard in training remains training on biological living peripheral nerve specimen, various inanimate models of nerve repair simulation have been described in the past years. The textile elastic band (TEB) obtained from a surgical mask was either covered with a fine silicone sheath or was left bare and was used afterward for end-to-end coaptation. The average diameter of the TEB was 2 mm, similar with the nerves in the distal hand and can be easily crafted out of accessiblematerials such as a surgicalmask and silicone sealant. The silicone that covers the TEB offers more fidelity to the simulation for microsurgical nerve coaptation. The TEB model offers an affordable, available, and easy-to-craft alternative to the existing models for peripheral nerve repair simulation and serves as a good initiation tool before moving on to biological specimens.

Modified Urethral Graciloplasty Cross-Innervated by the Pudendal Nerve for Postprostatectomy Urinary Incontinence: Cadaveric Simulation Surgery and a Clinical Case Report

  • Hisashi Sakuma;Masaki Yazawa;Makoto Hikosaka;Yumiko Uchikawa-Tani;Masayoshi Takayama;Kazuo Kishi
    • Archives of Plastic Surgery
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    • v.50 no.6
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    • pp.578-585
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    • 2023
  • An artificial sphincter implanted in the bulbous urethra to treat severe postprostatectomy urinary incontinence is effective, but embedding-associated complications can occur. We assessed the feasibility, efficacy, and safety of urethral graciloplasty cross-innervated by the pudendal nerve. A simulation surgery on three male fresh cadavers was performed. Both ends of the gracilis muscle were isolated only on its vascular pedicle with proximal end of the obturator nerve severed and transferred to the perineum. We examined whether the gracilis muscle could be wrapped around the bulbous urethra and whether the obturator nerve was long enough to suture with the pudendal nerve. In addition, surgery was performed on a 71-year-old male patient with severe urinary incontinence. The postoperative 12-month outcomes were assessed using a 24-hour pad test and urodynamic study. In all cadaveric simulations, the gracilis muscles could be wrapped around the bulbous urethra in a γ-loop configuration. The length of the obturator nerve was sufficient for neurorrhaphy with the pudendal nerve. In the clinical case, the postoperative course was uneventful. The mean maximum urethral closure pressure and functional profile length increased from 40.7 to 70 cm H2O and from 40.1 to 45.3 mm, respectively. Although urinary incontinence was not completely cured, the patient was able to maintain urinary continence at night. Urethral graciloplasty cross-innervated by the pudendal nerve is effective in raising the urethral pressure and reducing urinary incontinence.

Inducibility of human atrial fibrillation in an in silico model reflecting local acetylcholine distribution and concentration

  • Hwang, Minki;Lee, Hyun-Seung;Pak, Hui-Nam;Shim, Eun Bo
    • The Korean Journal of Physiology and Pharmacology
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    • v.20 no.1
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    • pp.111-117
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    • 2016
  • Vagal nerve activity has been known to play a crucial role in the induction and maintenance of atrial fibrillation (AF). However, it is unclear how the distribution and concentration of local acetylcholine (ACh) promotes AF. In this study, we investigated the effect of the spatial distribution and concentration of ACh on fibrillation patterns in an in silico human atrial model. A human atrial action potential model with an ACh-dependent $K^+$ current ($I_{KAch}$) was used to examine the effect of vagal activation. A simulation of cardiac wave dynamics was performed in a realistic 3D model of the atrium. A model of the ganglionated plexus (GP) and nerve was developed based on the "octopus hypothesis". The pattern of cardiac wave dynamics was examined by applying vagal activation to the GP areas or randomly. AF inducibility in the octopus hypothesis-based GP and nerve model was tested. The effect of the ACh concentration level was also examined. In the single cell simulation, an increase in the ACh concentration shortened $APD_{90}$ and increased the maximal slope of the restitution curve. In the 3D simulation, a random distribution of vagal activation promoted wavebreaks while ACh secretion limited to the GP areas did not induce a noticeable change in wave dynamics. The octopus hypothesis-based model of the GP and nerve exhibited AF inducibility at higher ACh concentrations. In conclusion, a 3D in silico model of the GP and parasympathetic nerve based on the octopus model exhibited higher AF inducibility with higher ACh concentrations.

Permanent Peripheral Nerve Stimulation for Chronic Occipital Neuralgia -Case reports- (만성 후두통을 영구적 후두신경자극기로 치료한 경험 -증례보고-)

  • Park, Chan Hong;Huh, Billy K
    • The Korean Journal of Pain
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    • v.21 no.2
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    • pp.155-158
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    • 2008
  • This report presents the application of occipital nerve stimulation in two patients with severe and disabling bilateral occipital neuralgia. Pain persisted despite the use of several procedures and the administration of medication in the patients. The patients underwent peripheral nerve stimulation for the treatment of headache. Peripheral nerve stimulation was accomplished via implantation of a subcutaneous electrode to stimulate the peripheral nerve in the occipital area. The patients reported a 90% improvement in overall pain. These cases illustrate the possible utilization of peripheral nerve stimulation for the treatment of occipital neuralgia.

Reconstruction of the Inferior Orbital Wall with Simplified Simulation Technique in Case of the Fracture Extending to the Posterior Orbital Floor

  • Kim, Kyu Nam;Kim, Hoon
    • Journal of International Society for Simulation Surgery
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    • v.3 no.2
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    • pp.80-83
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    • 2016
  • A 37-year-old male was assaulted and complained of severe periorbital swelling. Physical examination revealed that there were limitation of eyeball movement on upper gaze, diplopia, and hypoesthesia on the infraorbital nerve innervating region. Three-dimensional (3D) computed tomography (CT) of facial bone exhibited the fracture of orbital floor accompanying the significant amount of orbital contents' herniation extending to the far posterior part. To recover the orbital volume and restore orbital floor without threatening the optic nerve, preoperative simplified simulation was applied. The posterior margin of the fractured orbit was delineated with simulation technique using cross-linkage between the coronal and sagittal sections based on the referential axial view of the CT scans. Dissection, reduction of orbital contents, and insertion of the absorbable mesh plate molded after the prefabricated template by the simulation technique was performed. Extensive orbital floor defect was successfully reconstructed and there were no serious complications. The purpose of this report is to emphasize the necessity of preoperative simulation in case of restoring the extensive orbital floor defect.

A Simulation Study on Improvements of Speech Processing Strategy of Cochlear Implants Using Adaptation Effect of Inner Hair Cell and Auditory Nerve Synapse (청각신경 시냅스의 적응 효과를 이용한 인공와우 어음처리 알고리즘의 개선에 대한 시뮬레이션 연구)

  • Kim, Jin-Ho;Kim, Kyung-Hwan
    • Journal of Biomedical Engineering Research
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    • v.28 no.2
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    • pp.205-211
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    • 2007
  • A novel envelope extraction algorithm for speech processor of cochlear implants, called adaptation algorithm, was developed which is based on a adaptation effect of the inner hair cell(IHC)/auditory nerve(AN) synapse. We achieved acoustic simulation and hearing experiments with 12 normal hearing persons to compare this adaptation algorithm with existent standard envelope extraction method. The results shows that speech processing strategy using adaptation algorithm showed significant improvements in speech recognition rate under most channel/noise condition, compared to conventional strategy We verified that the proposed adaptation algorithm may yield better speech perception under considerable amount of noise, compared to the conventional speech processing strategy.

Modeling the human memory in nerve fields

  • Fujita, Osamu;Kakazu, Yukinori
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10b
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    • pp.70-73
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    • 1992
  • This paper describes the modeling of human memory using a nerve field model which is proposed for modeling the mechanism of brain mathematically. In our model, two phases of memory, retention and recollection, are focused on. The former consists of two stages, short-term memory (STM) and long-term memory (LTM). The proposed model consists of three parts, the STM Layer, LTM Layer and the Intermediate Layer between them. Each of these is constructed by a nerve field. In the STM Layer, memorized information is retained dynamically in the form of the reverberating states of units within the layer, while in the LTM Layer, it is stored statically in the form of structures of the weight on the links between units. the Intermediate Layer is introduced to translate this dynamic representation in the STM Layer to the LTNI Layer, and also to extract the static information from the STM Layer. In addition to this, we consider the recollection of information stored in the LTM. Finally, the behavior of this model is demonstrated by computer simulation.

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Continuous Epidural Block in a 6 Year old Girl with Causalgia (6세 소녀의 하지 작열통에 대한 지속적 경막외 차단)

  • Han, Chung-Sun;Yoon, Duck-Mi;Oh, Hung-Kun;Chung, Kyung-Suk
    • The Korean Journal of Pain
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    • v.4 no.2
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    • pp.186-190
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    • 1991
  • Causalgia is an extremely incapacitating disease often associated with a major peripheral nerve injury, which is characterized by sustained diffuse burning pain, allodynia and hyperpathia. The condition follows traumatic nerve lesions, often combined with vasomotor and sudomotor disturbances and later trophic changes. While sympathectomy has been the classical treatment of causalgia, others nonsurgical therapies such as regional sympathetic block, IV regional sympathetic block, oral adrenolytic drugs, transcutaneous electrical nerve simulation, physical theraphy, cryotheraphy and psychotheraphy have been used. Causalgia is rare in children and early treatment is controversial because of the possibility of many different complications following aggressive treatment. This is a report of a 6-year-old girl with causalgia suffered after a right posterior tibial nerve injury following an intragluteal injection of an antipyretics. We successfully treated this syndrome with continuous epidural block using 0.5% lidocaine and no specific complication was encountered.

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Case Report of Radial Nerve palsy patients treated with acupuncture and Neuromuscular Electrical Stimulation (침(鍼)과 Neuromuscular Electrical Simulation으로 치료한 요골신경마비에 대한 증례보고)

  • Hwang, Wook;Kim, Jeung-shin;Bae, Ki-tae;Nam, Sang-soo;Kim, Yong-suk
    • Journal of Acupuncture Research
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    • v.21 no.6
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    • pp.249-257
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    • 2004
  • Objective : Radial nerve palsy is characterized by palsy or paralysis of extensors of the wrist and digits, as well as the forearm supinators. Very proximal lesions also may affect the triceps. Numbness occurs on the dorsoradial aspect of the hand and the dorsal aspect of the radial 3 and 1/2 digits. We observed 7 patients with radial nerve palsy, the results are as follows. Methods & Results : All patients were treated by the same method and treatment was performed by acupuncture and Neuromuscular Electrical Stimulation. the electrode were placed unilaterally on the motor points of forearm. As the result, symptoms are improved remarkably. Conclusions : Patients were treated for 5.4 weeks, 14.7 times(average). The grade was that 6 cases were good and 1 case was excellent.

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Performance evaluation of fieldbus protocol using simulation (시뮬레이션을 이용한 필드버스 프로토콜의 성능 평가)

  • Lee, Gyung-Chang;Kim, In-Joon;Lee, Seok
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.676-679
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    • 1997
  • Networking for manufacturing is gaining importance as a nerve system of computer-integrated manufacturing(CIM). Among the various network types, the most inexpensive type called fieldbus is specifically aimed to interconnect simple devices such as sensors and actuators. For this purpose, there are several choices of the protocol such as Profibus, FIP, Foundation Fieldbus, and IEC/ISA fieldbus. This paper presents the simulation results of Profibus and FIP. Both protocols has been simulated in order to evaluate the performance such as transmission delay and throughput under different protocol parameter setting and traffic conditions.

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