Browsing by Author "Iversen, Edwin"

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    A NEW ELECTRIC SYSTEM WITH SIMULTANEOUS ELBOW & HAND CONTROL
    (2005) Sears, Harold; Iversen, Edwin; Hays, Kevin; Madsen, Ron
    The evolution of electric prosthetic systems has resulted in the widespread transition to digital controllers, i.e., microprocessors. In fact, it may be true that every available electronic controller in the field of prosthetics will soon be a digital controller. In our own experience, the ProControl 2 was introduced seven years ago, which provided digital control of hand and wrist. The last seven years have brought new generations of improved software (the newest version is 5.1.2, so five generations have evolved), as well as development of new sensors. Also, continued evolution of commercial microprocessors has resulted in more powerful controllers, in even smaller sizes than were available previously. In December of 2002, initial units of the Utah Arm 3 with electric elbow, hand, and wrist functions were prepared, including completely new digital controllers for elbow, hand, and wrist. Five units were placed into field trial usage on every-day wearers of a transhumeral (or higher level) electric arm prosthesis. The number has been increased as improvements have been implemented, although until January 2005 all were considered “Beta Units,” and the early ones upgraded with the improvements to the circuits, or other components.
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    Association of time-temperature curves with outcomes in temperature management for cardiac arrest.
    (BMJ neurology open, 2022-01) Luedke, Matthew William; Graffagnino, Carmelo; McKinney, B Grace; Piper, Jill; Iversen, Edwin; Kolls, Brad

    Background/purpose

    Cardiac arrest is a common cause of death and neurological injury; therapeutic cooling for neuroprotection is standard of care. Despite numerous and ongoing trials targeting a specified cooling temperature for a target duration, the concept of temperature dose-the duration spent at a given depth of hypothermia-is not as well explored.

    Methods

    In this retrospective study, we examined 66 patients 18 years of age or older undergoing therapeutic hypothermia for cardiac arrest between 2007 and 2010 to assess the relationship of temperature dose with outcomes. Demographic, clinical, outcome and temperature data were collected. Demographic and clinical data underwent bivariate regression analysis for association with outcome. Time-temperature curves were divided into pre-determined temperature thresholds and assessed by logistic regression analysis for association with outcome. A second, multivariate regression analysis was performed controlling for factors associated with poor outcomes.

    Results

    Old age was significantly associated with poor outcome and a shockable arrest rhythm was significantly associated with positive outcome. Subjects spent an average of 2.82 hours below 35°C, 7.31 hours ≥35°C to ≤36.5°C, 24.75 hours >36.5 to <38.0°C and 7.06 hours ≥38°C. Logistic regression analysis revealed borderline significant positive association between good outcome and time at a cooling depth (35°C-36.5°C, p=0.05); adjusted for old age, the association became significant (p=0.04).

    Conclusion

    Controlling for old age, longer durations between >35°C, ≤36.5°C during therapeutic hypothermia for cardiac arrest were significantly associated with good clinical outcomes. Time spent within a given temperature range may be useful for measuring the effect of temperature management.
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    Erythrocyte folate concentrations, CpG methylation at genomically imprinted domains, and birth weight in a multiethnic newborn cohort.
    (Epigenetics, 2014-08) Hoyo, Cathrine; Daltveit, Anne Kjersti; Iversen, Edwin; Benjamin-Neelon, Sara E; Fuemmeler, Bernard; Schildkraut, Joellen; Murtha, Amy P; Overcash, Francine; Vidal, Adriana C; Wang, Frances; Huang, Zhiqing; Kurtzberg, Joanne; Seewaldt, Victoria; Forman, Michele; Jirtle, Randy L; Murphy, Susan K
    Epigenetic mechanisms are proposed to link maternal concentrations of methyl group donor nutrients with the risk of low birth weight. However, empirical data are lacking. We have examined the association between maternal folate and birth weight and assessed the mediating role of DNA methylation at nine differentially methylated regions (DMRs) of genomically imprinted genes in these associations. Compared with newborns of women with folate levels in the lowest quartile, birth weight was higher in newborns of mothers in the second (β = 143.2, se = 63.2, P = 0.02), third (β = 117.3, se = 64.0, P = 0.07), and fourth (β = 133.9, se = 65.2, P = 0.04) quartiles, consistent with a threshold effect. This pattern of association did not vary by race/ethnicity but was more apparent in newborns of non-obese women. DNA methylation at the PLAGL1, SGCE, DLK1/MEG3 and IGF2/H19 DMRs was associated with maternal folate levels and also birth weight, suggestive of threshold effects. MEG3 DMR methylation mediated the association between maternal folate levels and birth weight (P =0.06). While the small sample size and partial scope of examined DMRs limit our conclusions, our data suggest that, with respect to birth weight, no additional benefits may be derived from increased maternal folate concentrations, especially in non-obese women. These data also support epigenetic plasticity as a key mechanistic response to folate availability during early fetal development.
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    EVALUATION STUDIES OF NEW ELECTRIC TERMINAL DEVICES
    (2005) Sears, Harold H.; Iversen, Edwin; Archer, Shawn; Linder, James; MacDonald, Joanna R.
    Two new electric terminal devices (TDs) have been developed for use with myoelectric prostheses of the upper limb, at all levels. They each feature a quick disconnect wrist connection, so they may be interchanged with each other, and also with existing electric TDs from other manufacturers
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    Evolution of the Utah Arm to Improve User Function
    (2008) Sears, Harold H.; Iversen, Edwin; Archer, Shawn; Jacobs, Tony
    An ambitious re-development of the Utah Arm was guided by direct clinical feedback, producing a list of features to improve the full-electric prostheses. The goals of the development focused on the following: • Smoother transition from elbow motion to hand function, and vice versa, i.e., more effortless locking and unlocking by the wearer, with many more locking positions. • Quieter operation of the elbow, both during the locking and unlocking operations (which can produce an audible “click” of the lock pin}, and during the powered freeswing function, which produces audible motor and gear noise. • More convenient connection of the prosthesis to the prosthetist’s or therapist’s computer for adjustment and training, which required a hard-wired connection of cables. • Wider range of input devices, as well as TDs, to take advantage of all available input sensors and output devices. Rather than “start over”, the technical capabilities and approach of the existing Utah Arm fullelectric system were used as a starting point, giving more advantages than disadvantages. Development time is greatly shortened by taking the approach of modifying an existing component, without the risks of using unproven designs. It is important to realize as well – the product is intended for clinical, rather than laboratory use, so practicality is of a very high priority.
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    Expression signatures of TP53 mutations in serous ovarian cancers.
    (BMC Cancer, 2010-05-26) Bernardini, Marcus Q; Baba, Tsukasa; Lee, Paula S; Barnett, Jason C; Sfakianos, Gregory P; Secord, Angeles Alvarez; Murphy, Susan K; Iversen, Edwin; Marks, Jeffrey R; Berchuck, Andrew
    BACKGROUND: Mutations in the TP53 gene are extremely common and occur very early in the progression of serous ovarian cancers. Gene expression patterns that relate to mutational status may provide insight into the etiology and biology of the disease. METHODS: The TP53 coding region was sequenced in 89 frozen serous ovarian cancers, 40 early stage (I/II) and 49 advanced stage (III/IV). Affymetrix U133A expression data was used to define gene expression patterns by mutation, type of mutation, and cancer stage. RESULTS: Missense or chain terminating (null) mutations in TP53 were found in 59/89 (66%) ovarian cancers. Early stage cancers had a significantly higher rate of null mutations than late stage disease (38% vs. 8%, p < 0.03). In advanced stage cases, mutations were more prevalent in short term survivors than long term survivors (81% vs. 30%, p = 0.0004). Gene expression patterns had a robust ability to predict TP53 status within training data. By using early versus late stage disease for out of sample predictions, the signature derived from early stage cancers could accurately (86%) predict mutation status of late stage cancers. CONCLUSIONS: This represents the first attempt to define a genomic signature of TP53 mutation in ovarian cancer. Patterns of gene expression characteristic of TP53 mutation could be discerned and included several genes that are known p53 targets or have been described in the context of expression signatures of TP53 mutation in breast cancer.
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    Utah Arm 2: New Technologies Applied To Electric Elbow And Hand Systems
    (1997) Sears, Harold H.; Iversen, Edwin; Dyck, Arthur D.; Hays, Kevin; Rivera, Caesar
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    Wrist Innovations To Improve Function of Electric Terminal Devices
    (2008) Sears, Harold H.; Iversen, Edwin; Archer, Shawn; Jacobs, Tony
    A major challenge in the development of terminal device (TD) and UE prosthetic devices is to add to the functional benefits to the wearer, without greatly increasing the weight, or complexity, or the cost of the prosthesis. Using existing TD designs, the opportunity existed to increase the function by increasing the degree of freedom available at the wrist, in several ways. Since the existing hands and electric terminal devices (ETD) were both single degree-of-freedom TDs, improving the positionability of the TD can logically improve the gripping orientation and grip security. Our goal was therefore, to improve positionability of TDs via improved wrist flexion/extension devices, and an improved wrist rotation device, which could be added in a modular fashion to the existing MC Hand, and ETD already developed and used extensively in the field.