The Experts below are selected from a list of 1116 Experts worldwide ranked by ideXlab platform

B. Ziaie - One of the best experts on this subject based on the ideXlab platform.

  • Modeling and characterization of a valved glaucoma drainage device with implications for enhanced therapeutic efficacy
    IEEE Transactions on Biomedical Engineering, 2005
    Co-Authors: V.h. Barocas, J.d. Brown, B. Ziaie
    Abstract:

    We report on modeling and bench test results targeted at better understanding of valved glaucoma drainage devices (GDDs), a common current surgical treatment for glaucoma. A simple equivalent circuit is described to model fluid mechanical behavior of the aqueous humor in an eye with glaucoma, both before and after implantation of a valved GDD. Finite element method simulations (FEM), based on the lubrication-von Ka/spl acute/rma/spl acute/n model, are then performed to analyze the valve's mechanical and fluidic performance. Using nanoporous membranes to mimic the in vivo Fibrous Capsule, we have developed a microfluidic bench test to simulate the aqueous humor flow and the post-implantation Fibrous tissue encapsulation around the GDD back plate. Our numerical and bench test results show that, contrary to the prevailing belief, the valve significantly contributes to the total pressure drop even after Fibrous Capsule Formation. Furthermore, we show that bypassing the valve through a simple polyimide tube insertion will dramatically lower the intraocular pressure (IOP) after Fibrous Capsule Formation. This may offer a new treatment option in some patients with advanced glaucoma.

  • Microfluidic characterization of a valved glaucoma drainage device with implications for enhanced therapeutic efficacy
    Proceedings of the 25th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (IEEE Cat. No.03CH37439), 2003
    Co-Authors: Z. Li, J.d. Brown, B. Ziaie
    Abstract:

    In this paper, we report on the microfluidic characterization of a valved glaucoma drainage device (the Ahmed/spl trade/ glaucoma valve). Using a microfluidic test set-up, we have simulated the aqueous humor flow and post implantation Fibrous tissue encapsulation of the external plate. We have shown that, contrary to the prevailing belief, the valve significantly contributes to the total pressure even after the Fibrous Capsule Formation. This was demonstrated both by disabling the valve using sharp dissection, and by bypassing it using a polyimide microtube. ANSYS/spl trade/ and Fluent/spl trade/ simulations verified the pressure measurements following the microtube insertion. Further reduction of intraocular pressure after Fibrous Capsule Formation could significantly reduce the potential for glaucoma progression.

  • A microfluid test-bed with nanopore membranes for in-vitro simulation of flow characteristics of glaucoma drainage devices
    Proceedings of the Second Joint 24th Annual Conference and the Annual Fall Meeting of the Biomedical Engineering Society] [Engineering in Medicine and, 1
    Co-Authors: Tingrui Pan, J.d. Brown, B. Ziaie
    Abstract:

    In this paper, we report on a microfluidic test-bed for in-vitro simulation of flow characteristics of valved-glaucoma drainage devices. A nanopore membrane is used to mimic the Fibrous tissue encapsulation of the sub-conjunctival plate following surgery. Pressure measurements with and without the valve clearly demonstrated the persisting effect of the microvalve in regulating the intraocular pressure subsequent to the Fibrous Capsule Formation.

Hala Zreiqat - One of the best experts on this subject based on the ideXlab platform.

  • effects of material tissue interactions on bone regeneration outcomes using baghdadite implants in a large animal model
    Advanced Healthcare Materials, 2018
    Co-Authors: Jiao Jiao Li, Austin J Akey, Colin R Dunstan, Martin Vielreicher, Oliver Friedrich, David C Bell, Hala Zreiqat
    Abstract:

    : Extensive bone loss due to trauma or disease leads to impaired healing. Current bone grafts and substitutes have major drawbacks that limit their effectiveness for treating large bone defects. A number of bone substitutes in development are undergoing preclinical testing, but few studies specifically investigate the in vivo material-tissue interactions that provide an important indicator to long-term implant safety and efficacy. This study is the first of its kind to specifically investigate in vivo material-tissue interactions at the bone-implant interface. Baghdadite scaffolds implanted in critical-sized segmental defects in sheep tibia for 26 weeks are analyzed by focused ion beam scanning electron microscopy, multiphoton microscopy, and histology. The scaffolds are seen to induce extensive bone Formation that directly abut the implant surfaces with no evidence of chronic inflammation or Fibrous Capsule Formation. Bone remodeling is influenced by slow in vivo degradation around and within the implant, causing portions of the implant to be incorporated into the newly formed bone. These findings have important implications for predicting the long-term effects of baghdadite ceramics in promoting defect healing, and support the translation of baghdadite scaffolds as a new generation of bone graft substitutes with improved properties for the repair of large bone defects.

  • effects of material tissue interactions on bone regeneration outcomes using baghdadite implants in a large animal model
    Advanced Healthcare Materials, 2018
    Co-Authors: Austin J Akey, Colin R Dunstan, Martin Vielreicher, Oliver Friedrich, David C Bell, Hala Zreiqat
    Abstract:

    Extensive bone loss due to trauma or disease leads to impaired healing. Current bone grafts and substitutes have major drawbacks that limit their effectiveness for treating large bone defects. A number of bone substitutes in development are undergoing preclinical testing, but few studies specifically investigate the in vivo material-tissue interactions that provide an important indicator to long-term implant safety and efficacy. This study is the first of its kind to specifically investigate in vivo material-tissue interactions at the bone-implant interface. Baghdadite scaffolds implanted in critical-sized segmental defects in sheep tibia for 26 weeks are analyzed by focused ion beam scanning electron microscopy, multiphoton microscopy, and histology. The scaffolds are seen to induce extensive bone Formation that directly abut the implant surfaces with no evidence of chronic inflammation or Fibrous Capsule Formation. Bone remodeling is influenced by slow in vivo degradation around and within the implant, causing portions of the implant to be incorporated into the newly formed bone. These findings have important implications for predicting the long-term effects of baghdadite ceramics in promoting defect healing, and support the translation of baghdadite scaffolds as a new generation of bone graft substitutes with improved properties for the repair of large bone defects.

J.d. Brown - One of the best experts on this subject based on the ideXlab platform.

  • Modeling and characterization of a valved glaucoma drainage device with implications for enhanced therapeutic efficacy
    IEEE Transactions on Biomedical Engineering, 2005
    Co-Authors: V.h. Barocas, J.d. Brown, B. Ziaie
    Abstract:

    We report on modeling and bench test results targeted at better understanding of valved glaucoma drainage devices (GDDs), a common current surgical treatment for glaucoma. A simple equivalent circuit is described to model fluid mechanical behavior of the aqueous humor in an eye with glaucoma, both before and after implantation of a valved GDD. Finite element method simulations (FEM), based on the lubrication-von Ka/spl acute/rma/spl acute/n model, are then performed to analyze the valve's mechanical and fluidic performance. Using nanoporous membranes to mimic the in vivo Fibrous Capsule, we have developed a microfluidic bench test to simulate the aqueous humor flow and the post-implantation Fibrous tissue encapsulation around the GDD back plate. Our numerical and bench test results show that, contrary to the prevailing belief, the valve significantly contributes to the total pressure drop even after Fibrous Capsule Formation. Furthermore, we show that bypassing the valve through a simple polyimide tube insertion will dramatically lower the intraocular pressure (IOP) after Fibrous Capsule Formation. This may offer a new treatment option in some patients with advanced glaucoma.

  • Microfluidic characterization of a valved glaucoma drainage device with implications for enhanced therapeutic efficacy
    Proceedings of the 25th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (IEEE Cat. No.03CH37439), 2003
    Co-Authors: Z. Li, J.d. Brown, B. Ziaie
    Abstract:

    In this paper, we report on the microfluidic characterization of a valved glaucoma drainage device (the Ahmed/spl trade/ glaucoma valve). Using a microfluidic test set-up, we have simulated the aqueous humor flow and post implantation Fibrous tissue encapsulation of the external plate. We have shown that, contrary to the prevailing belief, the valve significantly contributes to the total pressure even after the Fibrous Capsule Formation. This was demonstrated both by disabling the valve using sharp dissection, and by bypassing it using a polyimide microtube. ANSYS/spl trade/ and Fluent/spl trade/ simulations verified the pressure measurements following the microtube insertion. Further reduction of intraocular pressure after Fibrous Capsule Formation could significantly reduce the potential for glaucoma progression.

  • A microfluid test-bed with nanopore membranes for in-vitro simulation of flow characteristics of glaucoma drainage devices
    Proceedings of the Second Joint 24th Annual Conference and the Annual Fall Meeting of the Biomedical Engineering Society] [Engineering in Medicine and, 1
    Co-Authors: Tingrui Pan, J.d. Brown, B. Ziaie
    Abstract:

    In this paper, we report on a microfluidic test-bed for in-vitro simulation of flow characteristics of valved-glaucoma drainage devices. A nanopore membrane is used to mimic the Fibrous tissue encapsulation of the sub-conjunctival plate following surgery. Pressure measurements with and without the valve clearly demonstrated the persisting effect of the microvalve in regulating the intraocular pressure subsequent to the Fibrous Capsule Formation.

V.h. Barocas - One of the best experts on this subject based on the ideXlab platform.

  • Modeling and characterization of a valved glaucoma drainage device with implications for enhanced therapeutic efficacy
    IEEE Transactions on Biomedical Engineering, 2005
    Co-Authors: V.h. Barocas, J.d. Brown, B. Ziaie
    Abstract:

    We report on modeling and bench test results targeted at better understanding of valved glaucoma drainage devices (GDDs), a common current surgical treatment for glaucoma. A simple equivalent circuit is described to model fluid mechanical behavior of the aqueous humor in an eye with glaucoma, both before and after implantation of a valved GDD. Finite element method simulations (FEM), based on the lubrication-von Ka/spl acute/rma/spl acute/n model, are then performed to analyze the valve's mechanical and fluidic performance. Using nanoporous membranes to mimic the in vivo Fibrous Capsule, we have developed a microfluidic bench test to simulate the aqueous humor flow and the post-implantation Fibrous tissue encapsulation around the GDD back plate. Our numerical and bench test results show that, contrary to the prevailing belief, the valve significantly contributes to the total pressure drop even after Fibrous Capsule Formation. Furthermore, we show that bypassing the valve through a simple polyimide tube insertion will dramatically lower the intraocular pressure (IOP) after Fibrous Capsule Formation. This may offer a new treatment option in some patients with advanced glaucoma.

Tomoaki Kano - One of the best experts on this subject based on the ideXlab platform.

  • Fibrous Capsule Formation of the peritoneal catheter tip in ventriculoperitoneal shunt: Two case reports.
    Surgical neurology international, 2014
    Co-Authors: Tomoaki Kano
    Abstract:

    A Fibrous Capsule Formation of a peritoneal catheter tip has not previously been researched as a complication of ventriculoperitoneal (VP) shunts. Two adult patients who had undergone a VP shunt for communicative hydrocephalus following subarachnoid hemorrhage caused by a ruptured aneurysm have been identified with malfunction of the VP shunt system by mild disturbance of consciousness and gait disturbance or loss of appetite. Hydrocephalus was diagnosed by computed tomography and the obstruction of the peritoneal catheter was revealed by shuntgraphy. Laparoscopy was performed and the peritoneal catheter tips were obstructed by Fibrous white Capsules that covered them. One was a thin membranous Capsule like a stocking with two small endoluminal granulomas of the peritoneal catheter, and other one was a Fibrous glossy white Capsule like a sock. These Fibrous Capsules were excised by laparoscopy forceps without the conversion to a new peritoneal catheter. Following the procedure, the shunt functioned normally. The pathological diagnoses were peritoneum with foreign body reaction or hyalinization of membranous tissue surrounded by Fibrous tissue. These Fibrous Capsules might be formed by the peritoneal reaction to cerebrospinal fluid as a foreign material. As such, a periodic medical check should be scheduled since a Fibrous Capsule of the peritoneal catheter tip might be formed again.

  • Fibrous Capsule Formation of the peritoneal catheter tip in ventriculoperitoneal shunt: Two case reports
    Surgical Neurology International, 2014
    Co-Authors: Tomoaki Kano
    Abstract:

    Background: A Fibrous Capsule Formation of a peritoneal catheter tip has not previously been researched as a complication of ventriculoperitoneal (VP) shunts. Case Description: Two adult patients who had undergone a VP shunt for communicative hydrocephalus following subarachnoid hemorrhage caused by a ruptured aneurysm have been identified with malfunction of the VP shunt system by mild disturbance of consciousness and gait disturbance or loss of appetite. Hydrocephalus was diagnosed by computed tomography and the obstruction of the peritoneal catheter was revealed by shuntgraphy. Laparoscopy was performed and the peritoneal catheter tips were obstructed by Fibrous white Capsules that covered them. One was a thin membranous Capsule like a stocking with two small endoluminal granulomas of the peritoneal catheter, and other one was a Fibrous glossy white Capsule like a sock. These Fibrous Capsules were excised by laparoscopy forceps without the conversion to a new peritoneal catheter. Following the procedure, the shunt functioned normally. The pathological diagnoses were peritoneum with foreign body reaction or hyalinization of membranous tissue surrounded by Fibrous tissue. Conclusion: These Fibrous Capsules might be formed by the peritoneal reaction to cerebrospinal fluid as a foreign material. As such, a periodic medical check should be scheduled since a Fibrous Capsule of the peritoneal catheter tip might be formed again.