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Qasemi A, Aminian A, Erfanian A. Real-time prediction of bladder urine leakage using fuzzy inference system and dual Kalman filtering in cats. Sci Rep 2024; 14:3879. [PMID: 38365925 PMCID: PMC10873426 DOI: 10.1038/s41598-024-53629-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 02/02/2024] [Indexed: 02/18/2024] Open
Abstract
The use of electrical stimulation devices to manage bladder incontinence relies on the application of continuous inhibitory stimulation. However, continuous stimulation can result in tissue fatigue and increased delivered charge. Here, we employ a real-time algorithm to provide a short-time prediction of urine leakage using the high-resolution power spectrum of the bladder pressure during the presence of non-voiding contractions (NVC) in normal and overactive bladder (OAB) cats. The proposed method is threshold-free and does not require pre-training. The analysis revealed that there is a significant difference between voiding contraction (VC) and NVC pressures as well as band powers (0.5-5 Hz) during both normal and OAB conditions. Also, most of the first leakage points occurred after the maximum VC pressure, while all of them were observed subsequent to the maximum VC spectral power. Kalman-Fuzzy method predicted urine leakage on average 2.2 s and 1.6 s before its occurrence and an average of 2.0 s and 1.1 s after the contraction started with success rates of 94.2% and 100% in normal and OAB cats, respectively. This work presents a promising approach for developing a neuroprosthesis device, with on-demand stimulation to control bladder incontinence.
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Affiliation(s)
- Amirhossein Qasemi
- Department of Biomedical Engineering, School of Electrical Engineering, Iran Neural Technology Research Center, Iran University of Science and Technology (IUST), Tehran, Iran
| | - Alireza Aminian
- Department of Biomedical Engineering, School of Electrical Engineering, Iran Neural Technology Research Center, Iran University of Science and Technology (IUST), Tehran, Iran
| | - Abbas Erfanian
- Department of Biomedical Engineering, School of Electrical Engineering, Iran Neural Technology Research Center, Iran University of Science and Technology (IUST), Tehran, Iran.
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2
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Yousefpour A, Erfanian A. A general framework for automatic closed-loop control of bladder voiding induced by intraspinal microstimulation in rats. Sci Rep 2021; 11:3424. [PMID: 33564019 PMCID: PMC7873267 DOI: 10.1038/s41598-021-82933-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 01/27/2021] [Indexed: 12/13/2022] Open
Abstract
Individuals with spinal cord injury or neurological disorders have problems in voiding function due to the dyssynergic contraction of the urethral sphincter. Here, we introduce a closed-loop control of intraspinal microstimulation (ISMS) for efficient bladder voiding. The strategy is based on asynchronous two-electrode ISMS with combined pulse-amplitude and pulse-frequency modulation without requiring rhizotomy, neurotomy, or high-frequency blocking. Intermittent stimulation is alternately applied to the two electrodes that are implanted in the S2 lateral ventral horn and S1 dorsal gray commissure, to excite the bladder motoneurons and to inhibit the urethral sphincter motoneurons. Asynchronous stimulation would lead to reduce the net electric field and to maximize the selective stimulation. The proposed closed-loop system attains a highly voiding efficiency of 77.2-100%, with an average of 91.28 ± 8.4%. This work represents a promising approach to the development of a natural and robust motor neuroprosthesis device for restoring bladder functions.
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Affiliation(s)
- Abolhasan Yousefpour
- Department of Biomedical Engineering, School of Electrical Engineering, Iran Neural Technology Research Center, Iran University of Science and Technology (IUST), Tehran, Iran
| | - Abbas Erfanian
- Department of Biomedical Engineering, School of Electrical Engineering, Iran Neural Technology Research Center, Iran University of Science and Technology (IUST), Tehran, Iran.
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Throckmorton G, Cayce J, Ricks Z, Adams WR, Jansen ED, Mahadevan-Jansen A. Identifying optimal parameters for infrared neural stimulation in the peripheral nervous system. NEUROPHOTONICS 2021; 8:015012. [PMID: 33816649 PMCID: PMC8010905 DOI: 10.1117/1.nph.8.1.015012] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 02/17/2021] [Indexed: 05/19/2023]
Abstract
Significance: Infrared neural stimulation (INS) utilizes pulsed infrared light to selectively elicit neural activity without exogenous compounds. Despite its versatility in a broad range of biomedical applications, no comprehensive comparison of factors pertaining to the efficacy and safety of INS such as wavelength, radiant exposure, and optical spot size exists in the literature. Aim: Here, we evaluate these parameters using three of the wavelengths commonly used for INS, 1450 nm, 1875 nm, and 2120 nm. Approach: In an in vivo rat sciatic nerve preparation, the stimulation threshold and transition rate to 100% activation probability were used to compare the effects of each parameter. Results: The pulsed diode lasers at 1450 nm and 1875 nm had a consistently higher ( ∼ 1.0 J / cm 2 ) stimulation threshold than that of the Ho:YAG laser at 2120 nm ( ∼ 0.7 J / cm 2 ). In addition, the Ho:YAG produced a faster transition rate to 100% activation probability compared to the diode lasers. Our data suggest that the superior performance of the Ho:YAG is a result of the high-intensity microsecond spike at the onset of the pulse. Acute histological evaluation of diode irradiated nerves revealed a safe range of radiant exposures for stimulation. Conclusion: Together, our results identify measures to improve the safety, efficacy, and accessibility of INS technology for research and clinical applications.
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Affiliation(s)
- Graham Throckmorton
- Vanderbilt Biophotonics Center, Keck FEL Center, Nashville, Tennessee, United States
- Vanderbilt University, Department of Biomedical Engineering, Nashville, Tennessee, United States
| | - Jonathan Cayce
- Vanderbilt Biophotonics Center, Keck FEL Center, Nashville, Tennessee, United States
- Vanderbilt University, Department of Biomedical Engineering, Nashville, Tennessee, United States
| | - Zane Ricks
- Vanderbilt Biophotonics Center, Keck FEL Center, Nashville, Tennessee, United States
- Vanderbilt University, Department of Biomedical Engineering, Nashville, Tennessee, United States
| | - Wilson R. Adams
- Vanderbilt Biophotonics Center, Keck FEL Center, Nashville, Tennessee, United States
- Vanderbilt University, Department of Biomedical Engineering, Nashville, Tennessee, United States
| | - Eric Duco Jansen
- Vanderbilt Biophotonics Center, Keck FEL Center, Nashville, Tennessee, United States
- Vanderbilt University, Department of Biomedical Engineering, Nashville, Tennessee, United States
- Vanderbilt University Medical Center, Department of Neurological Surgery, Nashville, Tennessee, United States
| | - Anita Mahadevan-Jansen
- Vanderbilt Biophotonics Center, Keck FEL Center, Nashville, Tennessee, United States
- Vanderbilt University, Department of Biomedical Engineering, Nashville, Tennessee, United States
- Vanderbilt University Medical Center, Department of Neurological Surgery, Nashville, Tennessee, United States
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4
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Chang TC, Wang M, Arbabian A. Multi-Access Networking with Wireless Ultrasound-Powered Implants. IEEE BIOMEDICAL CIRCUITS AND SYSTEMS CONFERENCE : HEALTHCARE TECHNOLOGY : [PROCEEDINGS]. IEEE BIOMEDICAL CIRCUITS AND SYSTEMS CONFERENCE 2020; 2019. [PMID: 31989118 DOI: 10.1109/biocas.2019.8919144] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Multi-access networking with miniaturized wireless implantable devices can enable and advance closed-loop medical applications to deliver precise diagnosis and treatment. Using ultrasound (US) for wireless implant systems is an advantageous approach as US can beamform with high spatial resolution to efficiently power and address multiple implants in the network. To demonstrate these capabilities, we use wirelessly powered mm-sized implants with bidirectional communication links; uplink data communication measurements are performed using time, spatial, and frequency-division multiplexing schemes in tissue phantom. A 32-channel linear transmitter array and an external receiver are used as a base station to network with two implants that are placed 6.5 cm deep and spaced less than 1 cm apart. Successful wireless powering and uplink data communication around 100 kbps with a measured bit error rate below 10-4 are demonstrated for all three networking schemes, validating the multi-access networking feasibility of US wireless implant systems.
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Affiliation(s)
- Ting Chia Chang
- Electrical Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Max Wang
- Electrical Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Amin Arbabian
- Electrical Engineering, Stanford University, Stanford, CA, 94305, USA
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Detecting Bladder Biomarkers for Closed-Loop Neuromodulation: A Technological Review. Int Neurourol J 2018; 22:228-236. [PMID: 30599493 PMCID: PMC6312967 DOI: 10.5213/inj.1836246.123] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 12/11/2018] [Indexed: 12/19/2022] Open
Abstract
Neuromodulation was introduced for patients with poor outcomes from the existing traditional treatment approaches. It is well-established as an alternative, novel treatment option for voiding dysfunction. The current system of neuromodulation uses an open-loop system that only delivers continuous stimulation without considering the patient's state changes. Though the conventional open-loop system has shown positive clinical results, it can cause problems such as decreased efficacy over time due to neural habituation, higher risk of tissue damage, and lower battery life. Therefore, there is a need for a closed-loop system to overcome the disadvantages of existing systems. The closed-loop neuromodulation includes a system to monitor and stimulate micturition reflex pathways from the lower urinary tract, as well as the central nervous system. In this paper, we reviewed the current technological status to measure biomarker for closed-loop neuromodulation systems for voiding dysfunction.
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Peh WYX, Raczkowska MN, Teh Y, Alam M, Thakor NV, Yen SC. Closed-loop stimulation of the pelvic nerve for optimal micturition. J Neural Eng 2018; 15:066009. [PMID: 30181427 DOI: 10.1088/1741-2552/aadee9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Neural stimulation to restore bladder function has traditionally relied on open-loop approaches that used pre-set parameters, which do not adapt to suboptimal outcomes. The goal of this study was to examine the effectiveness of a novel closed-loop stimulation paradigm for improving micturition or bladder voiding. APPROACH We compared the voiding efficiency obtained with this closed-loop framework against open-loop stimulation paradigms in anesthetized rats. The bladder pressures that preceded voiding, and the minimum current amplitudes for stimulating the pelvic nerves to evoke bladder contractions, were first calibrated for each animal. An automated closed-loop system was used to initiate voiding upon bladder fullness, adapt the stimulation current by using real-time bladder pressure changes to classify voiding outcomes, and halt stimulation when the bladder had been emptied or when the safe stimulation limit was reached. MAIN RESULTS In vivo testing demonstrated that the closed-loop system achieved high voiding efficiency or VE (75.7% ± 3.07%, mean ± standard error of the mean) and outperformed open-loop systems with either conserved number of stimulation epochs (63.2% ± 4.90% VE) or conserved charge injected (32.0% ± 1.70% VE). Post-hoc analyses suggest that the classification algorithm can be further improved with data from additional closed-loop experiments. SIGNIFICANCE This novel approach may be applied to an implantable device for treating underactive bladder (<60% VE), especially in cases where under- or over-stimulation of the nerve is a concern.
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Affiliation(s)
- Wendy Yen Xian Peh
- Singapore Institute for Neurotechnology, National University of Singapore, 28 Medical Drive, #05-02, Singapore 117456, Singapore
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Charthad J, Chang TC, Liu Z, Sawaby A, Weber MJ, Baker S, Gore F, Felt SA, Arbabian A. A mm-Sized Wireless Implantable Device for Electrical Stimulation of Peripheral Nerves. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2018; 12:257-270. [PMID: 29578414 DOI: 10.1109/tbcas.2018.2799623] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
A wireless electrical stimulation implant for peripheral nerves, achieving >10× improvement over state of the art in the depth/volume figure of merit, is presented. The fully integrated implant measures just 2 mm × 3 mm × 6.5 mm (39 mm3, 78 mg), and operates at a large depth of 10.5 cm in a tissue phantom. The implant is powered using ultrasound and includes a miniaturized piezoelectric receiver (piezo), an IC designed in 180 nm HV BCD process, an off-chip energy storage capacitor, and platinum stimulation electrodes. The package also includes an optional blue light-emitting diode for potential applications in optogenetic stimulation in the future. A system-level design strategy for complete operation of the implant during the charging transient of the storage capacitor, as well as a unique downlink command/data transfer protocol, is presented. The implant enables externally programmable current-controlled stimulation of peripheral nerves, with a wide range of stimulation parameters, both for electrical (22 to 5000 μA amplitude, ∼14 to 470 μs pulse-width, 0 to 60 Hz repetition rate) and optical (up to 23 mW/mm2 optical intensity) stimulation. Additionally, the implant achieves 15 V compliance voltage for chronic applications. Full integration of the implant components, end-to-end in vitro system characterizations, and results for the electrical stimulation of a sciatic nerve, demonstrate the feasibility and efficacy of the proposed stimulator for peripheral nerves.
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8
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Peh WYX, Mogan R, Thow XY, Chua SM, Rusly A, Thakor NV, Yen SC. Novel Neurostimulation of Autonomic Pelvic Nerves Overcomes Bladder-Sphincter Dyssynergia. Front Neurosci 2018; 12:186. [PMID: 29618971 PMCID: PMC5871706 DOI: 10.3389/fnins.2018.00186] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 03/06/2018] [Indexed: 12/25/2022] Open
Abstract
The disruption of coordination between smooth muscle contraction in the bladder and the relaxation of the external urethral sphincter (EUS) striated muscle is a common issue in dysfunctional bladders. It is a significant challenge to overcome for neuromodulation approaches to restore bladder control. Bladder-sphincter dyssynergia leads to undesirably high bladder pressures, and poor voiding outcomes, which can pose life-threatening secondary complications. Mixed pelvic nerves are potential peripheral targets for stimulation to treat dysfunctional bladders, but typical electrical stimulation of pelvic nerves activates both the parasympathetic efferent pathway to excite the bladder, as well as the sensory afferent pathway that causes unwanted sphincter contractions. Thus, a novel pelvic nerve stimulation paradigm is required. In anesthetized female rats, we combined a low frequency (10 Hz) stimulation to evoke bladder contraction, and a more proximal 20 kHz stimulation of the pelvic nerve to block afferent activation, in order to produce micturition with reduced bladder-sphincter dyssynergia. Increasing the phase width of low frequency stimulation from 150 to 300 μs alone was able to improve voiding outcome significantly. However, low frequency stimulation of pelvic nerves alone evoked short latency (19.9–20.5 ms) dyssynergic EUS responses, which were abolished with a non-reversible proximal central pelvic nerve cut. We demonstrated that a proximal 20 kHz stimulation of pelvic nerves generated brief onset effects at lower current amplitudes, and was able to either partially or fully block the short latency EUS responses depending on the ratio of the blocking to stimulation current. Our results indicate that ratios >10 increased the efficacy of blocking EUS contractions. Importantly, we also demonstrated for the first time that this combined low and high frequency stimulation approach produced graded control of the bladder, while reversibly blocking afferent signals that elicited dyssynergic EUS contractions, thus improving voiding by 40.5 ± 12.3%. Our findings support advancing pelvic nerves as a suitable neuromodulation target for treating bladder dysfunction, and demonstrate the feasibility of an alternative method to non-reversible nerve transection and sub-optimal intermittent stimulation methods to reduce dyssynergia.
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Affiliation(s)
- Wendy Yen Xian Peh
- Singapore Institute for Neurotechnology, National University of Singapore, Singapore, Singapore
| | - Roshini Mogan
- Singapore Institute for Neurotechnology, National University of Singapore, Singapore, Singapore
| | - Xin Yuan Thow
- Singapore Institute for Neurotechnology, National University of Singapore, Singapore, Singapore
| | - Soo Min Chua
- Singapore Institute for Neurotechnology, National University of Singapore, Singapore, Singapore
| | - Astrid Rusly
- Singapore Institute for Neurotechnology, National University of Singapore, Singapore, Singapore
| | - Nitish V Thakor
- Singapore Institute for Neurotechnology, National University of Singapore, Singapore, Singapore.,Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore.,Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore.,Biomedical Engineering, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Shih-Cheng Yen
- Singapore Institute for Neurotechnology, National University of Singapore, Singapore, Singapore.,Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
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Lee S, Peh WYX, Wang J, Yang F, Ho JS, Thakor NV, Yen S, Lee C. Toward Bioelectronic Medicine-Neuromodulation of Small Peripheral Nerves Using Flexible Neural Clip. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2017; 4:1700149. [PMID: 29201608 PMCID: PMC5700646 DOI: 10.1002/advs.201700149] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2017] [Revised: 04/30/2017] [Indexed: 05/24/2023]
Abstract
Neural modulation technology and the capability to affect organ function have spawned the new field of bioelectronic medicine. Therapeutic interventions depend on wireless bioelectronic neural interfaces that can conformally and easily attach to small (few hundred micrometers) nerves located deep in the body without neural damage. Besides size, factors like flexibility and compliance to attach and adapt to visceral nerves associated moving organs are of paramount importance and have not been previously addressed. This study proposes a novel flexible neural clip (FNC) that can be used to interface with a variety of different peripheral nerves. To illustrate the flexibility of the design, this study stimulates the pelvic nerve, the vagus nerve, and branches of the sciatic nerve and evaluates the feasibility of the design in modulating the function of each of these nerves. It is found that this FNC allows fine-tuning of physiological processes such as micturition, heart rate, and muscle contractions. Furthermore, this study also tests the ability of wirelessly powered FNC to enable remote modulation of visceral pelvic nerves located deep in the body. These results show that the FNC can be used with a range of different nerves, providing one of the critical pieces in the field of bioelectronics medicines.
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Affiliation(s)
- Sanghoon Lee
- Department of Electrical and Computer EngineeringNational University of Singapore4 Engineering Drive 3Singapore117583Singapore
- Singapore Institute for Neurotechnology (SINAPSE)National University of Singapore28 Medical Drive, #05‐CORSingapore117456Singapore
- Center for Intelligent Sensors and MEMSNational University of Singapore4 Engineering Drive 3Singapore117576Singapore
- NUS Suzhou Research Institute (NUSRI)Industrial ParkSuzhou215123P. R. China
| | - Wendy Yen Xian Peh
- Singapore Institute for Neurotechnology (SINAPSE)National University of Singapore28 Medical Drive, #05‐CORSingapore117456Singapore
| | - Jiahui Wang
- Department of Electrical and Computer EngineeringNational University of Singapore4 Engineering Drive 3Singapore117583Singapore
- Singapore Institute for Neurotechnology (SINAPSE)National University of Singapore28 Medical Drive, #05‐CORSingapore117456Singapore
- Center for Intelligent Sensors and MEMSNational University of Singapore4 Engineering Drive 3Singapore117576Singapore
- NUS Suzhou Research Institute (NUSRI)Industrial ParkSuzhou215123P. R. China
| | - Fengyuan Yang
- Department of Electrical and Computer EngineeringNational University of Singapore4 Engineering Drive 3Singapore117583Singapore
- Singapore Institute for Neurotechnology (SINAPSE)National University of Singapore28 Medical Drive, #05‐CORSingapore117456Singapore
| | - John S. Ho
- Department of Electrical and Computer EngineeringNational University of Singapore4 Engineering Drive 3Singapore117583Singapore
- Singapore Institute for Neurotechnology (SINAPSE)National University of Singapore28 Medical Drive, #05‐CORSingapore117456Singapore
| | - Nitish V. Thakor
- Department of Electrical and Computer EngineeringNational University of Singapore4 Engineering Drive 3Singapore117583Singapore
- Singapore Institute for Neurotechnology (SINAPSE)National University of Singapore28 Medical Drive, #05‐CORSingapore117456Singapore
- Graduate School for Integrative Science and EngineeringNational University of SingaporeSingapore117456Singapore
- Department of Biomedical EngineeringSchool of MedicineJohns Hopkins UniversityBaltimoreMD21205USA
| | - Shih‐Cheng Yen
- Department of Electrical and Computer EngineeringNational University of Singapore4 Engineering Drive 3Singapore117583Singapore
- Singapore Institute for Neurotechnology (SINAPSE)National University of Singapore28 Medical Drive, #05‐CORSingapore117456Singapore
| | - Chengkuo Lee
- Department of Electrical and Computer EngineeringNational University of Singapore4 Engineering Drive 3Singapore117583Singapore
- Singapore Institute for Neurotechnology (SINAPSE)National University of Singapore28 Medical Drive, #05‐CORSingapore117456Singapore
- Center for Intelligent Sensors and MEMSNational University of Singapore4 Engineering Drive 3Singapore117576Singapore
- NUS Suzhou Research Institute (NUSRI)Industrial ParkSuzhou215123P. R. China
- Graduate School for Integrative Science and EngineeringNational University of SingaporeSingapore117456Singapore
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Al Adem KM, Bawazir SS, Hassen WA, Khandoker AH, Khalaf K, McGloughlin T, Stefanini C. Implantable Systems for Stress Urinary Incontinence. Ann Biomed Eng 2017; 45:2717-2732. [PMID: 29022114 DOI: 10.1007/s10439-017-1939-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 09/29/2017] [Indexed: 01/23/2023]
Abstract
Stress urinary incontinence (SUI), the involuntary urine leakage due to failure of the urethral closure mechanism, is a global health challenge with substantial human suffering and socioeconomic costs. Approximately 167 million male and female patients are predicted to suffer from SUI in 2018, worldwide. A wide range of surgical interventions are available for the treatment of SUI. Severe cases, however, usually require the implantation of artificial urinary sphincter devices. This review comparatively presents and analyzes the working principles, as well as the challenges, associated with the current implantable SUI systems in clinical use. These include slings, urethral bulking agents, artificial urinary sphincters, and adjustable continence devices. It further reports on recent research progress and state-of-the-art in the field of SUI implants, including an original approach proposed by the authors with a pressure feedback sensory mechanism. The new emerging field of artificial muscle devices, including electroactive polymers, provides a promising innovative solution for replacing the weakened urethral sphincter in SUI patients.
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Affiliation(s)
- Kenana M Al Adem
- Department of Biomedical Engineering, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, UAE
| | - Sarah S Bawazir
- Department of Biomedical Engineering, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, UAE
| | - Waleed A Hassen
- Cleveland Clinic Lerner College of Medicine of Case Western University, Cleveland, OH, USA
- Urology, Surgical Subspecialties Institute, Cleveland Clinic, Abu Dhabi, UAE
| | - Ahsan H Khandoker
- Department of Biomedical Engineering, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, UAE
| | - Kinda Khalaf
- Department of Biomedical Engineering, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, UAE
| | - Tim McGloughlin
- Department of Biomedical Engineering, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, UAE
| | - Cesare Stefanini
- Department of Biomedical Engineering, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, UAE.
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Gomma HW, El-Azab AS. Developing a treatment for neurogenic bladder dysfunction using Model Predictive Control (MPC). Biomed Signal Process Control 2017. [DOI: 10.1016/j.bspc.2017.03.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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12
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Realistic Electric Field Mapping of Anisotropic Muscle During Electrical Stimulation Using a Combination of Water Diffusion Tensor and Electrical Conductivity. Int Neurourol J 2017; 21:S32-38. [PMID: 28446015 PMCID: PMC5426426 DOI: 10.5213/inj.1734878.439] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 04/07/2017] [Indexed: 11/12/2022] Open
Abstract
Purpose To realistically map the electric fields of biological tissues using a diffusion tensor magnetic resonance electrical impedance tomography (DT-MREIT) method to estimate tissue response during electrical stimulation. Methods Imaging experiments were performed using chunks of bovine muscle. Two silver wire electrodes were positioned inside the muscle tissue for electrical stimulation. Electric pulses were applied with a 100-V amplitude and 100-μs width using a voltage stimulator. During electrical stimulation, we collected DT-MREIT data from a 3T magnetic resonance imaging scanner. We adopted the projected current density method to calculate the electric field. Based on the relation between the water diffusion tensor and the conductivity tensor, we computed the position-dependent scale factor using the measured magnetic flux density data. Then, a final conductivity tensor map was reconstructed using the multiplication of the water diffusion tensor and the scale factor. Results The current density images from DT-MREIT data represent the internal current flows that exist not only in the electrodes but also in surrounding regions. The reconstructed electric filed map from our anisotropic conductivity tensor with the projected current density shows coverage that is more than 2 times as wide, and higher signals in both the electrodes and surrounding tissues, than the previous isotropic method owing to the consideration of tissue anisotropy. Conclusions An electric field map obtained by an anisotropic reconstruction method showed different patterns from the results of the previous isotropic reconstruction method. Since accurate electric field mapping is important to correctly estimate the coverage of the electrical treatment, future studies should include more rigorous validations of the new method through in vivo and in situ experiments.
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Normann RA, Fernandez E. Clinical applications of penetrating neural interfaces and Utah Electrode Array technologies. J Neural Eng 2016; 13:061003. [PMID: 27762237 DOI: 10.1088/1741-2560/13/6/061003] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This paper briefly describes some of the recent progress in the development of penetrating microelectrode arrays and highlights the use of two of these devices, Utah electrode arrays and Utah slanted electrode arrays, in two therapeutic interventions: recording volitional skeletal motor commands from the central nervous system, and recording motor commands and evoking somatosensory percepts in the peripheral nervous system (PNS). The paper also briefly explores other potential sites for microelectrode array interventions that could be profitably pursued and that could have important consequences in enhancing the quality of life of patients that has been compromised by disorders of the central and PNSs.
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Affiliation(s)
- Richard A Normann
- Departments of Bioengineering and Ophthalmology, University of Utah, Salt Lake City, UT 84112, USA
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14
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Lee KS. Future directions in overactive bladder treatment: Personalized medicine can be applied? Korean J Urol 2015; 56:671-2. [PMID: 26495066 PMCID: PMC4610892 DOI: 10.4111/kju.2015.56.10.671] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Kyu-Sung Lee
- Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. ; Department of Medical Device Management and Research, SAIHST, Sungkyunkwan University, Seoul, Korea
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15
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Kim KH. The rise of on-demand research and specific applications: optogenetics in urology. Int Neurourol J 2015; 19:1-2. [PMID: 25833474 PMCID: PMC4386482 DOI: 10.5213/inj.2015.19.1.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
- Khae Hawn Kim
- Department of Urology, Gachon University Gil Medical Center, Incheon, Korea
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