W Kenneth Ward

Summary

Publications

  1. doi request reprint Increased expression of Interleukin-13 and connective tissue growth factor, and their potential roles during foreign body encapsulation of subcutaneous implants
    W Kenneth Ward
    Legacy Health System, 1225 NE 2nd Avenue, Portland, OR 97232, USA
    J Biomater Sci Polym Ed 19:1065-72. 2008
  2. doi request reprint Controlled release of dexamethasone from subcutaneously-implanted biosensors in pigs: localized anti-inflammatory benefit without systemic effects
    W Kenneth Ward
    Legacy Health System, Portland, Oregon, USA
    J Biomed Mater Res A 94:280-7. 2010
  3. ncbi request reprint An implantable subcutaneous glucose sensor array in ketosis-prone rats: closed loop glycemic control
    W Kenneth Ward
    Legacy Clinical Research and Technology Center, Portland, OR 97232, USA
    Artif Organs 29:131-43. 2005
  4. ncbi request reprint The role of new technology in the early detection of hypoglycemia
    W Kenneth Ward
    Clinical Research and Technology Center, Legacy Health System, Portland, Oregon 97232, USA
    Diabetes Technol Ther 6:115-7. 2004
  5. pmc Factors influencing the effectiveness of glucagon for preventing hypoglycemia
    Jessica R Castle
    Oregon Health and Science University, Portland, Oregon 97239, USA
    J Diabetes Sci Technol 4:1305-10. 2010
  6. pmc Continuous glucose monitoring in subjects with type 1 diabetes: improvement in accuracy by correcting for background current
    Joseph El Youssef
    Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
    Diabetes Technol Ther 12:921-8. 2010
  7. pmc A controlled study of the effectiveness of an adaptive closed-loop algorithm to minimize corticosteroid-induced stress hyperglycemia in type 1 diabetes
    Joseph El Youssef
    Oregon Health and Science University, Portland, Oregon, USA
    J Diabetes Sci Technol 5:1312-26. 2011
  8. doi request reprint Development of a fully automated closed loop artificial pancreas control system with dual pump delivery of insulin and glucagon
    Peter G Jacobs
    Portland VA Medical Center and the Oregon Health and Sciences University, Portland, OR 97239, USA
    Conf Proc IEEE Eng Med Biol Soc 2011:397-400. 2011
  9. pmc Amperometric glucose sensors: sources of error and potential benefit of redundancy
    Jessica R Castle
    Oregon Health Services University, Portland, Oregon, USA
    J Diabetes Sci Technol 4:221-5. 2010
  10. ncbi request reprint A novel insulin delivery algorithm in rats with type 1 diabetes: the fading memory proportional-derivative method
    Bala Gopakumaran
    Legacy Clinical Research and Technology Center, Portland, OR 97232, USA
    Artif Organs 29:599-607. 2005

Collaborators

Detail Information

Publications26

  1. doi request reprint Increased expression of Interleukin-13 and connective tissue growth factor, and their potential roles during foreign body encapsulation of subcutaneous implants
    W Kenneth Ward
    Legacy Health System, 1225 NE 2nd Avenue, Portland, OR 97232, USA
    J Biomater Sci Polym Ed 19:1065-72. 2008
    ....
  2. doi request reprint Controlled release of dexamethasone from subcutaneously-implanted biosensors in pigs: localized anti-inflammatory benefit without systemic effects
    W Kenneth Ward
    Legacy Health System, Portland, Oregon, USA
    J Biomed Mater Res A 94:280-7. 2010
    ..c) 2010 Wiley Periodicals, Inc. J Biomed Mater Res, 2010...
  3. ncbi request reprint An implantable subcutaneous glucose sensor array in ketosis-prone rats: closed loop glycemic control
    W Kenneth Ward
    Legacy Clinical Research and Technology Center, Portland, OR 97232, USA
    Artif Organs 29:131-43. 2005
    ..A revised algorithm yielded better glycemic control than the initial algorithm did. Future research needs to further improve calibration methods and reduce foreign body fibrosis in order to avoid a time-related increase in lag duration...
  4. ncbi request reprint The role of new technology in the early detection of hypoglycemia
    W Kenneth Ward
    Clinical Research and Technology Center, Legacy Health System, Portland, Oregon 97232, USA
    Diabetes Technol Ther 6:115-7. 2004
  5. pmc Factors influencing the effectiveness of glucagon for preventing hypoglycemia
    Jessica R Castle
    Oregon Health and Science University, Portland, Oregon 97239, USA
    J Diabetes Sci Technol 4:1305-10. 2010
    ..Administration of small, intermittent doses of glucagon during closed-loop insulin delivery markedly reduces the frequency of hypoglycemia. However, in some cases, hypoglycemia occurs despite administration of glucagon in this setting...
  6. pmc Continuous glucose monitoring in subjects with type 1 diabetes: improvement in accuracy by correcting for background current
    Joseph El Youssef
    Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
    Diabetes Technol Ther 12:921-8. 2010
    ..We also tested whether increasing the frequency of sensor calibration would improve sensor accuracy...
  7. pmc A controlled study of the effectiveness of an adaptive closed-loop algorithm to minimize corticosteroid-induced stress hyperglycemia in type 1 diabetes
    Joseph El Youssef
    Oregon Health and Science University, Portland, Oregon, USA
    J Diabetes Sci Technol 5:1312-26. 2011
    ..6 ± 0.5%. We conclude that an adaptive algorithm that frequently estimates insulin sensitivity and adjusts gain factors is capable of minimizing corticosteroid-induced stress hyperglycemia...
  8. doi request reprint Development of a fully automated closed loop artificial pancreas control system with dual pump delivery of insulin and glucagon
    Peter G Jacobs
    Portland VA Medical Center and the Oregon Health and Sciences University, Portland, OR 97239, USA
    Conf Proc IEEE Eng Med Biol Soc 2011:397-400. 2011
    ..Results from this work may ultimately lead to development of a portable, easy to use, artificial pancreas device that can enable far better glycemic control in patients with diabetes...
  9. pmc Amperometric glucose sensors: sources of error and potential benefit of redundancy
    Jessica R Castle
    Oregon Health Services University, Portland, Oregon, USA
    J Diabetes Sci Technol 4:221-5. 2010
    ..If an array with three or more sensors were available, it would likely allow even better accuracy with the use of voting...
  10. ncbi request reprint A novel insulin delivery algorithm in rats with type 1 diabetes: the fading memory proportional-derivative method
    Bala Gopakumaran
    Legacy Clinical Research and Technology Center, Portland, OR 97232, USA
    Artif Organs 29:599-607. 2005
    ..0 vs. 130 +/- 2.9 mg/dL). Neither version produced hypoglycemia. Future research using this algorithm needs to focus on automated glucose sensing in combination with insulin delivery...
  11. pmc Safe glycemic management during closed-loop treatment of type 1 diabetes: the role of glucagon, use of multiple sensors, and compensation for stress hyperglycemia
    W Kenneth Ward
    Oregon Health and Science University, Portland, Oregon 97239, USA
    J Diabetes Sci Technol 5:1373-80. 2011
    ..Elements such as the use of glucagon to minimize hypoglycemia, adaptation to changes in insulin sensitivity, and sensor redundancy will likely increase safety during outpatient use of closed-loop glycemic control systems...
  12. pmc The accuracy benefit of multiple amperometric glucose sensors in people with type 1 diabetes
    Jessica R Castle
    Department of Medicine, Division of Endocrinology, Diabetes and Clinical Nutrition, Oregon Health and Science University, Portland, Oregon, USA
    Diabetes Care 35:706-10. 2012
    ..To improve glucose sensor accuracy in subjects with type 1 diabetes by using multiple sensors and to assess whether the benefit of redundancy is affected by intersensor distance...
  13. ncbi request reprint Elevation of transforming growth factor beta (TGFbeta) and its downstream mediators in subcutaneous foreign body capsule tissue
    Allen G Li
    Department of Dermatology, Oregon Health and Science University, Portland, Oregon 97239, USA
    J Biomed Mater Res A 82:498-508. 2007
    ..We suggest that TGFbeta plays an important role in the FBC formation. Inhibition of TGFbeta signaling could be a promising strategy in the prevention of FBC formation, thereby extending the useful life of subcutaneous implants...
  14. ncbi request reprint The effect of local subcutaneous delivery of vascular endothelial growth factor on the function of a chronically implanted amperometric glucose sensor
    W Kenneth Ward
    Clinical Research and Technology Center, Legacy Health System, Portland, Oregon 97232
    Diabetes Technol Ther 6:137-45. 2004
    ..Slow release of angiogenic growth factors may be a potential method for chronically enhancing the function of a subcutaneously implanted biosensor...
  15. ncbi request reprint A fully implantable subcutaneous glucose sensor array: enhanced accuracy from multiple sensing units and a median-based algorithm
    W Kenneth Ward
    Legacy Clinical Research and Technology Center, Legacy Health System, Portland, Oregon 97232, USA
    Diabetes Technol Ther 5:943-52. 2003
    ..When tested in an implanted array of glucose sensors, a median-based technique (ZMAD) yields an accurate unified signal, and its accuracy is superior to signal averaging...
  16. ncbi request reprint Induction of type-1 diabetes mellitus in laboratory rats by use of alloxan: route of administration, pitfalls, and insulin treatment
    Isaac F Federiuk
    Legacy Clinical Research and Technology Center, 1225 NE 2nd Avenue, Portland, Oregon 97232, USA
    Comp Med 54:252-7. 2004
    ..If specific precautions are observed, intraperitoneal administration of high-dose alloxan to laboratory rats leads to a condition that closely resembles human type-1 DM...
  17. ncbi request reprint Vascularizing the tissue surrounding a model biosensor: how localized is the effect of a subcutaneous infusion of vascular endothelial growth factor (VEGF)?
    W Kenneth Ward
    Legacy Health System, Legacy Clinical Research and Technology Center, 1225 NE 2nd Avenue, Portland, OR 97232, USA
    Biosens Bioelectron 19:155-63. 2003
    ..Vascularization of a foreign body capsule surrounding a subcutaneous biosensor might well extend its useful life...
  18. doi request reprint Stable liquid glucagon formulations for rescue treatment and bi-hormonal closed-loop pancreas
    Melanie A Jackson
    Oregon Health and Science University OHSU, 3181 SW Sam Jackson Park Road, OP05DC, Portland, OR 97239, USA
    Curr Diab Rep 12:705-10. 2012
    ..Assays for cyclic AMP (cAMP) or its downstream effector, protein kinase A (PKA), in engineered cell systems, are more reliable and suitable for inexpensive, high-throughput assessment of bioactivity...
  19. pmc Novel use of glucagon in a closed-loop system for prevention of hypoglycemia in type 1 diabetes
    Jessica R Castle
    Department of Medicine, Division of Endocrinology, Oregon Health and Science University, Portland, Oregon, USA
    Diabetes Care 33:1282-7. 2010
    ..To minimize hypoglycemia in subjects with type 1 diabetes by automated glucagon delivery in a closed-loop insulin delivery system...
  20. pmc In vitro and in vivo evaluation of native glucagon and glucagon analog (MAR-D28) during aging: lack of cytotoxicity and preservation of hyperglycemic effect
    W Kenneth Ward
    Legacy Health System Research, Portland, Oregon 97232, USA
    J Diabetes Sci Technol 4:1311-21. 2010
    ..However, under some conditions, solutions of glucagon can form amyloid fibrils. Currently, the usage instructions for commercially available glucagon allow only for its immediate use...
  21. pmc Discomfort from an alkaline formulation delivered subcutaneously in humans: albumin at pH 7 versus pH 10
    W Kenneth Ward
    Legacy Health and Legacy Research Institute, Portland, OR, USA
    Clin Drug Investig 32:433-8. 2012
    ..There is a paucity of data regarding tolerability of alkaline drugs administered subcutaneously. The aim of this study was to assess the tolerability of alkaline preparations of human albumin delivered subcutaneously to healthy humans...
  22. ncbi request reprint A wire-based dual-analyte sensor for glucose and lactate: in vitro and in vivo evaluation
    W Kenneth Ward
    iSense Corporation, Portland, Oregon 97224, USA
    Diabetes Technol Ther 6:389-401. 2004
    ..This study constitutes proof of the concept that oxidase-based, amperometric wire microsensors can detect changes in glucose and lactate during subcutaneous implantation in rats...
  23. ncbi request reprint The effect of microgeometry, implant thickness and polyurethane chemistry on the foreign body response to subcutaneous implants
    W Kenneth Ward
    Legacy Clinical Research and Technology Center, 1225 NE 2nd Ave, Portland, OR 97232, USA
    Biomaterials 23:4185-92. 2002
    ..In addition, thin implants lead to a thin FBC. Porous implants (PVA and ePTFE) cause more angiogenesis than solid implants. These results may have implications for the measurement of blood-derived analytes by biosensors...
  24. ncbi request reprint A new amperometric glucose microsensor: in vitro and short-term in vivo evaluation
    W Kenneth Ward
    iSense Corporation, 16125 SW 72nd Avenue, Portland, OR 97224, USA
    Biosens Bioelectron 17:181-9. 2002
    ..The response of the revised protocol sensors (n=7) to intraperitoneal glucose was tested in rats approximately one day after subcutaneous implantation and the sensors tracked glucose closely with a slight lag of 3-6 min...
  25. ncbi request reprint Passivating protein coatings for implantable glucose sensors: evaluation of protein retention
    Steven J Geelhood
    Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, USA
    J Biomed Mater Res B Appl Biomater 81:251-60. 2007
    ..Preadsorbed proteins on polymers appear to be removed by passive exchange and/or displacement by plasma proteins and by proteases released by monocytes...
  26. ncbi request reprint Prevention of hypoglycemia using risk assessment with a continuous glucose monitoring system
    Carine Choleau
    INSERM U341, Diabetes Department, Hotel Dieu Hospital, Paris, France
    Diabetes 51:3263-73. 2002
    ..This was, of course, not the case when the same glucose load was infused at the detection of the hypoglycemia threshold...