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Yang X, Zhao R, Solav D, Yang X, Lee DR, Sparrman B, Fan Y, Herr H. Material, design, and fabrication of custom prosthetic liners for lower-extremity amputees: A review. MEDICINE IN NOVEL TECHNOLOGY AND DEVICES 2022. [DOI: 10.1016/j.medntd.2022.100197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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Steer JW, Worsley PR, Browne M, Dickinson A. Key considerations for finite element modelling of the residuum-prosthetic socket interface. Prosthet Orthot Int 2021; 45:138-146. [PMID: 33176573 DOI: 10.1177/0309364620967781] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 09/22/2020] [Indexed: 02/03/2023]
Abstract
BACKGROUND Finite element modelling has long been proposed to support prosthetic socket design. However, there is minimal detail in the literature to inform practice in developing and interpreting these complex, highly nonlinear models. OBJECTIVES To identify best practice recommendations for finite element modelling of lower limb prosthetics, considering key modelling approaches and inputs. STUDY DESIGN Computational modelling. METHODS This study developed a parametric finite element model using magnetic resonance imaging data from a person with transtibial amputation. Comparative analyses were performed considering socket loading methods, socket-residuum interface parameters and soft tissue material models from the literature, to quantify their effect on the residuum's biomechanical response to a range of parameterised socket designs. RESULTS These variables had a marked impact on the finite element model's predictions for limb-socket interface pressure and soft tissue shear distribution. CONCLUSIONS All modelling decisions should be justified biomechanically and clinically. In order to represent the prosthetic loading scenario in silico, researchers should (1) consider the effects of donning and interface friction to capture the generated soft tissue shear stresses, (2) use representative stiffness hyperelastic material models for soft tissues when using strain to predict injury and (3) interrogate models comparatively, against a clinically-used control.
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Affiliation(s)
- Joshua W Steer
- Bioengineering Science Research Group, School of Engineering, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
| | - Peter R Worsley
- Clinical Academic Facility, School of Health Sciences, Faculty of Environment and Life Sciences, University of Southampton, Southampton, UK
| | - Martin Browne
- Bioengineering Science Research Group, School of Engineering, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
| | - Alex Dickinson
- Bioengineering Science Research Group, School of Engineering, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
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Youngblood RT, Hafner BJ, Czerniecki JM, Brzostowski JT, Allyn KJ, Sanders JE. Modeling the mechanics of elevated vacuum systems in prosthetic sockets. Med Eng Phys 2020; 84:75-83. [PMID: 32977925 DOI: 10.1016/j.medengphy.2020.07.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 07/24/2020] [Indexed: 10/23/2022]
Abstract
Elevated vacuum (EV) is suggested to improve suspension and limb volume management for lower limb prosthesis users. However, few guidelines have been established to facilitate configuration of EV sockets to ensure their safe and proper function. A benchtop model of an EV socket was created to study how prosthetic liner tensile elasticity, socket fit, and socket vacuum pressure affect liner displacement and subsequent pressure on the residual limb. A domed carbon fiber layup was used to represent an EV socket. Inserts were used to simulate various air gaps between the socket and liner. Various prosthetic liner samples were placed under the carbon fiber layup. Liner displacement and the corresponding pressure change underneath the liner were measured as vacuum was applied between the liner sample and socket wall. Tissue vacuum pressure increased linearly with socket vacuum pressure until the liner contacted the socket wall. Predicted tissue vacuum pressure matched well with experimental results. Findings suggest that the effect of vacuum pressure on the residual limb is primarily determined by air gap distance. The developed model may be used to assess effects of EV on residual limb tissues based on an individual's socket fit, liner characteristics, and applied vacuum. Understanding the physiological effects of EV on the residual limb could help practitioners avoid blister formation and improve EV implementation.
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Affiliation(s)
| | - Brian J Hafner
- Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA
| | - Joseph M Czerniecki
- Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA; VA Center for Limb Loss and Mobility, VA Puget Sound Health Care System, Seattle, WA, USA
| | | | - Katheryn J Allyn
- Department of Bioengineering, University of Washington, Seattle WA, USA
| | - Joan E Sanders
- Department of Bioengineering, University of Washington, Seattle WA, USA
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Rankin K, Steer J, Paton J, Mavrogordato M, Marter A, Worsley P, Browne M, Dickinson A. Developing an Analogue Residual Limb for Comparative DVC Analysis of Transtibial Prosthetic Socket Designs. MATERIALS 2020; 13:ma13183955. [PMID: 32906701 PMCID: PMC7557588 DOI: 10.3390/ma13183955] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/01/2020] [Accepted: 09/02/2020] [Indexed: 12/18/2022]
Abstract
Personalised prosthetic sockets are fabricated by expert clinicians in a skill- and experience-based process, with research providing tools to support evidence-based practice. We propose that digital volume correlation (DVC) may offer a deeper understanding of load transfer from prosthetic sockets into the residual limb, and tissue injury risk. This study’s aim was to develop a transtibial amputated limb analogue for volumetric strain estimation using DVC, evaluating its ability to distinguish between socket designs. A soft tissue analogue material was developed, comprising silicone elastomer and sand particles as fiducial markers for image correlation. The material was cast to form an analogue residual limb informed by an MRI scan of a person with transtibial amputation, for whom two polymer check sockets were produced by an expert prosthetist. The model was micro-CT scanned according to (i) an unloaded noise study protocol and (ii) a case study comparison between the two socket designs, loaded to represent two-legged stance. The scans were reconstructed to give 108 µm voxels. The DVC noise study indicated a 64 vx subvolume and 50% overlap, giving better than 0.32% strain sensitivity, and ~3.5 mm spatial resolution of strain. Strain fields induced by the loaded sockets indicated tensile, compressive and shear strain magnitudes in the order of 10%, with a high signal:noise ratio enabling distinction between the two socket designs. DVC may not be applicable for socket design in the clinical setting, but does offer critical 3D strain information from which existing in vitro and in silico tools can be compared and validated to support the design and manufacture of prosthetic sockets, and enhance the biomechanical understanding of the load transfer between the limb and the prosthesis.
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Affiliation(s)
- Kathryn Rankin
- Bioengineering Science Research Group, School of Engineering, University of Southampton, Southampton SO17 1BJ, UK; (K.R.); (J.S.); (J.P.); (A.M.); (M.B.)
- µ-VIS X-Ray Imaging Centre, University of Southampton, Southampton SO17 1BJ, UK;
| | - Joshua Steer
- Bioengineering Science Research Group, School of Engineering, University of Southampton, Southampton SO17 1BJ, UK; (K.R.); (J.S.); (J.P.); (A.M.); (M.B.)
| | - Joshua Paton
- Bioengineering Science Research Group, School of Engineering, University of Southampton, Southampton SO17 1BJ, UK; (K.R.); (J.S.); (J.P.); (A.M.); (M.B.)
| | - Mark Mavrogordato
- µ-VIS X-Ray Imaging Centre, University of Southampton, Southampton SO17 1BJ, UK;
| | - Alexander Marter
- Bioengineering Science Research Group, School of Engineering, University of Southampton, Southampton SO17 1BJ, UK; (K.R.); (J.S.); (J.P.); (A.M.); (M.B.)
| | - Peter Worsley
- Skin Health Research Group, School of Health Sciences, University of Southampton, Southampton SO16 6YD, UK;
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - Martin Browne
- Bioengineering Science Research Group, School of Engineering, University of Southampton, Southampton SO17 1BJ, UK; (K.R.); (J.S.); (J.P.); (A.M.); (M.B.)
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - Alexander Dickinson
- Bioengineering Science Research Group, School of Engineering, University of Southampton, Southampton SO17 1BJ, UK; (K.R.); (J.S.); (J.P.); (A.M.); (M.B.)
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, UK
- Correspondence: ; Tel.: +44-(238)-059-5394
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Quinlan J, Yohay J, Subramanian V, Poziembo B, Fatone S. Using mechanical testing to assess the effect of lower-limb prosthetic socket texturing on longitudinal suspension. PLoS One 2020; 15:e0237841. [PMID: 32813733 PMCID: PMC7437898 DOI: 10.1371/journal.pone.0237841] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 07/27/2020] [Indexed: 11/18/2022] Open
Abstract
To function effectively, a lower limb prosthetic socket must remain securely coupled to the residual limb during walking, running and other activities of daily living; this coupling is referred to as suspension. When this coupling is insufficient longitudinal pistoning of the socket relative to the residual limb occurs. Increasing friction of the socket/liner interface may improve socket suspension and textured sockets may be fabricated relatively easily with 3D printing. The aim of this study was to investigate longitudinal displacement of sockets with different types of textures under two suspension conditions: passive suction and active vacuum. In order to do this, we developed a mock residual limb and mechanical testing protocol. Prosthetic sockets, 14 textured sockets and an Original Squirt-Shape (OSS) Socket, were fabricated from polypropylene copolymer using the Squirt-Shape™ 3D Printer and compared to a smooth socket thermoformed from polypropylene copolymer. Sockets were mounted onto a dual durometer mock residual limb and subjected to four levels of distraction forces (100 N, 250 N, 500 N and 650 N) using a hydraulic material testing system. There was a statistically significant three-way interaction between suspension, force level and texture (p < 0.0005). Longitudinal displacements between textured and reference sockets, for all force levels and both suspension conditions, were significantly different (p < 0.0005). Using these newly developed mechanical testing protocols, it was demonstrated that texturing of polypropylene copolymer sockets fabricated using Squirt-Shape significantly decreased longitudinal displacements compared to a smooth socket. However, none of the novel textured sockets significantly reduced longitudinal displacement compared to the OSS socket under passive suction suspension.
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Affiliation(s)
- Julia Quinlan
- Department of Physical Medicine and Rehabilitation, Northwestern University Prosthetics-Orthotics Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - Jessica Yohay
- Department of Physical Medicine and Rehabilitation, Northwestern University Prosthetics-Orthotics Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - Vasanth Subramanian
- Department of Physical Medicine and Rehabilitation, Northwestern University Prosthetics-Orthotics Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - Brad Poziembo
- Prosthetic Design Inc, Dayton, Ohio, United States of America
| | - Stefania Fatone
- Department of Physical Medicine and Rehabilitation, Northwestern University Prosthetics-Orthotics Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
- * E-mail:
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Quintero-Quiroz C, Botero LE, Zárate-Triviño D, Acevedo-Yepes N, Escobar JS, Pérez VZ, Cruz Riano LJ. Synthesis and characterization of a silver nanoparticle-containing polymer composite with antimicrobial abilities for application in prosthetic and orthotic devices. Biomater Res 2020; 24:13. [PMID: 32817803 PMCID: PMC7425163 DOI: 10.1186/s40824-020-00191-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 07/22/2020] [Indexed: 01/24/2023] Open
Abstract
Background The presence of skin problems in patients using external lower limb prosthesis is recurrent. This has generated the need to develop interfaces for prosthesis with the ability to control microbial growth. Silver nanoparticles (AgNPs) have been implemented in the development of biomaterials because of their high antimicrobial activity. This article discusses the development of an AgNP-containing polymer composite with antimicrobial activity for developing prosthetic liners. Methods AgNPs were synthesized using a photochemical method and certain physicochemical properties were characterized. Furthermore, the antimicrobial activity of AgNPs against Staphylococcus aureus ATCC 25923 and methicillin-resistant Staphylococcus aureus (MRSA), was assessed on the basis of their minimum inhibitory concentrations (MICs). AgNPs were incorporated into a silicon elastomer to assess certain physicomechanical properties, antimicrobial activity and cytotoxic effect of the material. Results The maximum antimicrobial activity of the material against Staphylococcus aureus ATCC 25923 and MRSA was 41.58% ±2.97% at AgNP concentration of 32.98 μg/mL and 14.85% ±5.94% at AgNP concentration of 16.49 μg/mL, respectively. Additionally, the material exhibited tensile yield strength, rupture tensile strength, and tensile modulus of elasticity of 0.70 - 1.10 MPa, 0.71–1.06 MPa, and 0.20 - 0.30 MPa, respectively. The mechanical characteristics of the material were within the acceptable range for use in external lower limb prosthetic and orthotic interfaces. Conclusions It was possible to incorporate the AgNPs in a silicone elastomer, finding that the composite developed presented antimicrobial activity against Staphylococcus aureus ATCC 25923 and MRSA when compared to non-AgNP material samples.
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Affiliation(s)
- Catalina Quintero-Quiroz
- Centro de Bioingeniería, Grupo de investigaciones en Bioingeniería, Universidad Pontificia Bolivariana, circular 1 No. 73-76, Medellín, 050031 Colombia
| | - Luz E Botero
- Grupo de Investigación de Biología de Sistemas,Universidad Pontificia Bolivariana, Cl 78B No. 72A-109, Medellín, 050031 Colombia
| | - Diana Zárate-Triviño
- Laboratorio de Inmunología y Virología, Universidad Autónoma de Nuevo León, Ave. Pedro de Alba S/N Ciudad Universitaria San Nicolás de los Garza, Monterrey, 64450 México
| | - Natalia Acevedo-Yepes
- Centro de Bioingeniería, Grupo de investigaciones en Bioingeniería, Universidad Pontificia Bolivariana, circular 1 No. 73-76, Medellín, 050031 Colombia
| | - Jorge Saldarriaga Escobar
- Grupo de Investigación Sobre Nuevos Materiales, Universidad Pontificia Bolivariana, Cq.1 No. 70-01, Medellín, 050031 Colombia
| | - Vera Z Pérez
- Centro de Bioingeniería, Grupo de investigaciones en Bioingeniería, Universidad Pontificia Bolivariana, circular 1 No. 73-76, Medellín, 050031 Colombia.,Facultad de Ingeniería Eléctrica y Electrónica, Cq.1 No. 70-01, Medellín, 050031 Colombia
| | - Luis Javier Cruz Riano
- Grupo de Investigación Sobre Nuevos Materiales, Universidad Pontificia Bolivariana, Cq.1 No. 70-01, Medellín, 050031 Colombia
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Using mechanical testing to assess texturing of prosthetic sockets to improve suspension in the transverse plane and reduce rotation. PLoS One 2020; 15:e0233148. [PMID: 32525868 PMCID: PMC7289418 DOI: 10.1371/journal.pone.0233148] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 04/28/2020] [Indexed: 11/21/2022] Open
Abstract
Creating a secure and comfortable linkage between the residual limb and prosthetic socket in persons with lower limb amputation is a critical factor for successful rehabilitation, including ambulation and other activities of daily living. Unwanted rotation within the socket can be a clinical problem for prosthesis users. One way of addressing issues experienced with transverse plane control of the socket may be through increased friction interface forces. It has been proposed that friction at the residual limb/socket interface may be increased by adding texture to interface components. Three-dimensional (3D) printing may be used to fabricate sockets with texture patterns added to the inner socket surface. Hence, the aim of this study was to investigate the effects of socket texturing on transverse plane rotation of the socket on a mock residual limb under two suspension conditions: passive suction and active vacuum. To conduct this study, we developed a mechanical testing protocol as no standardized tests currently exist to assess prosthetic sockets. Sockets with 14 different texture patterns were fabricated using the Squirt-Shape™ 3D printer. Textured sockets were compared to an Original Squirt-Shape (OSS) socket and a smooth thermoformed socket. Sockets were fitted with a mock residual limb and bi-axially loaded to 350 N compression with simultaneous rotation (2.5°, 5° and 7.5°) using a custom rotation assembly attached to a uniaxial hydraulic material testing system. There was a statistically significant three-way interaction between suspension, angle and texture (p < 0.0005). Torques between textured and reference sockets, for all rotation angles and both suspension conditions, were significantly different (p < 0.0005). Using newly developed testing protocols, it was demonstrated that some texture patterns significantly increased torque (i.e., resistance against unwanted rotation) in the transverse plane compared to both OSS and smooth sockets, especially for passive suction. Rotation testing of sockets may provide insight into socket design to improve suspension in the transverse plane.
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Characterization of Prosthetic Liner Products for People with Transtibial Amputation. ACTA ACUST UNITED AC 2018; 30:187-199. [PMID: 30906148 DOI: 10.1097/jpo.0000000000000205] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Cagle JC, Reinhall PG, Allyn KJ, McLean J, Hinrichs P, Hafner BJ, Sanders JE. A finite element model to assess transtibial prosthetic sockets with elastomeric liners. Med Biol Eng Comput 2018; 56:1227-1240. [PMID: 29235055 PMCID: PMC5999538 DOI: 10.1007/s11517-017-1758-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Accepted: 11/20/2017] [Indexed: 11/24/2022]
Abstract
People with transtibial amputation often experience skin breakdown due to the pressures and shear stresses that occur at the limb-socket interface. The purpose of this research was to create a transtibial finite element model (FEM) of a contemporary prosthesis that included complete socket geometry, two frictional interactions (limb-liner and liner-socket), and an elastomeric liner. Magnetic resonance imaging scans from three people with characteristic transtibial limb shapes (i.e., short-conical, long-conical, and cylindrical) were acquired and used to develop the models. Each model was evaluated with two loading profiles to identify locations of focused stresses during stance phase. The models identified five locations on the participants' residual limbs where peak stresses matched locations of mechanically induced skin issues they experienced in the 9 months prior to being scanned. The peak contact pressure across all simulations was 98 kPa and the maximum resultant shear stress was 50 kPa, showing reasonable agreement with interface stress measurements reported in the literature. Future research could take advantage of the developed FEM to assess the influence of changes in limb volume or liner material properties on interface stress distributions. Graphical abstract Residual limb finite element model. Left: model components. Right: interface pressures during stance phase.
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Affiliation(s)
- John C Cagle
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Per G Reinhall
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Kate J Allyn
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Jake McLean
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Paul Hinrichs
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Brian J Hafner
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Joan E Sanders
- Department of Bioengineering, University of Washington, Seattle, WA, USA.
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Weathersby EJ, Cagle JC, Larsen BG, Henrikson KM, Sanders JE. Development of a magnetic composite material for measurement of residual limb displacements in prosthetic sockets. J Rehabil Assist Technol Eng 2018; 5:2055668318763481. [PMID: 31191930 PMCID: PMC6453102 DOI: 10.1177/2055668318763481] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 02/12/2018] [Indexed: 11/16/2022] Open
Abstract
INTRODUCTION Wearable limb-socket displacement sensors may help patients and prosthetists identify a deteriorating socket fit and justify the need for repair or replacement. METHODS A novel sensor using an inductive sensing modality was developed to detect limb-to-socket distances. Key detection elements were a coil antenna placed in the socket wall and a magnetic composite sheath worn over the outside of the prosthesis user's elastomeric liner. The sheath was a nylon or cotton prosthetic stocking coated with a polyurethane composite. The polyurethane composite contained embedded iron particles (75 wt%). RESULTS Brushing γ-glycidoxypropyltriethoxysilane onto the sheath fabric, coating it first with unfilled polyurethane and then iron-filled polyurethane, enhanced bonding between the sheath and the composite and overcame mechanical degradation problems. A γ-glycidoxypropyltriethoxysilane-rich fumed silica layer applied to the outside of the sheath reduced friction and improved durability. Field testing demonstrated less than a 3% signal degradation from four weeks of field use. CONCLUSIONS The developed wearable displacement sensor meets durability and performance needs, and is ready for large-scale clinical testing.
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Affiliation(s)
| | - John C Cagle
- Department of Bioengineering, University of
Washington, Seattle, USA
| | - Brian G Larsen
- Department of Bioengineering, University of
Washington, Seattle, USA
| | | | - Joan E Sanders
- Department of Bioengineering, University of
Washington, Seattle, USA
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