Powered lower limb prosthetics hold promise for improving the mobility of amputees, but errors in the technology may also cause some users to stumble or fall. New research examines exactly what happens when these technologies fail, with the goal of developing a new generation of more robust powered prostheses.

"My work has focused on developing technology that translates electrical signals in human muscle into signals that control powered prosthetic limbs - such as decoding muscle signals to tell a prosthetic leg that it needs to walk forward or step up onto a staircase," says Dr. Helen Huang, senior author of a paper on the work and an associate professor in the joint biomedical engineering program at North Carolina State University and the University of North Carolina at Chapel Hill.

"But sometimes this 'decoding' technology makes mistakes, such as thinking someone wants to climb a step when he doesn't," says Fan Zhang, lead author of the paper and a Ph.D. student in the joint biomedical engineering program. "This is a problem, because we don't want to put users at risk of stumbling or falling."

Huang's team set out to understand exactly what happens to users of powered prosthetic legs when there's an error in the decoding technology.

"We not only want to improve the decoding accuracy, but determine which errors are important and which have little or no impact on users," Huang says. "Understanding the problem is an important step in finding ways to make these prostheses more reliable."

To address the issue, the researchers had study subjects use a customized prosthetic device that was programmed to make errors. This was done in a lab setting that allowed Huang's team to monitor each user's balance and biomechanics. Users were also asked how stable they felt during each trial.

The researchers found that some errors were so insignificant that users didn't even notice them - particularly errors that were short in duration or that occurred when a user's weight was not being applied to the prosthetic leg.

But errors that lasted longer, or that occurred when a user's weight was on the prosthetic limb, were more noticeable. The researchers also determined that critical, or especially noticeable, errors were also characterized by a large "mechanical work change," meaning the prosthetic limb thought it had to do significantly more or less work than the user intended.

"One of the things we'll be doing as we move forward with this work is seek ways to limit that mechanical work change," Huang says.

"Any system that involves a human interface will have occasional errors," Huang notes. "But we think we can find ways to make those errors effectively insignificant."

The paper, "Effects of Locomotion Mode Recognition Errors on Volitional Control of Powered Above-Knee Prostheses," is published in early view online in the journal IEEE Transactions on Neural Systems and Rehabilitation Engineering. The paper was co-authored by Ming Liu, a laboratory manager in the joint biomedical engineering program. The work was supported by the National Science Foundation under grants number 1406750 and 1361549, by the Department of Defense under grant number W81XWH-09-2-0020, and by the National Institute on Disability and Rehabilitation Research under grant number H133G130308.

Milner Placed on Reserve

MOLINE, Ill. (November 20, 2014) - Goaltender John Curry has been assigned to the Quad City Mallards by the American Hockey League's Iowa Wild and the Mallards have placed goaltender Parker Milner on reserve, the Mallards announced today.

Curry, 30, has posted a 3.72 goals against average and .885 save percentage while going 0-4-0 in five games with Iowa this season. 

"John is here for a stint to get some playing time before going back to Iowa," said Mallards coach and general manager Terry Ruskowski.  "We look forward to having him here because he's a character guy and an excellent goaltender."

Curry played two National Hockey League games for the Minnesota Wild last season- going 1-0-0 with a 3.00 goals against average and .930 save percentage- and has played six career NHL games for the Wild and Pittsburgh Penguins.  The 5' 11", 185-pound Shorewood, Minnesota, native has gone 3-2-0 and turned in a 3.54 goals against average and .893 save percentage in those six games.

Curry last season divided his time among Minnesota, Iowa and the ECHL's Orlando Solar Bears.  In 19 AHL games he was 7-9-2 with a 2.62 goals against average, a .920 save percentage and one shutout.  He ran up a record of 10-2-0 with Orlando on a 2.66 goals against average and .917 save percentage.

Curry has spent the bulk of his eight-year professional career in the AHL.  He has gone 103-63-7 with a 2.51 goals against average, a .907 save percentage and ten shutouts in 183 American League games with the Wilkes-Barre/Scranton Penguins, Houston Aeros and Wild.   As a rookie he backstopped Wilkes-Barre/Scranton to a berth in the 2008 AHL Calder Cup finals.

After spending his first four seasons in the Penguins' organization Curry moved abroad to spend the 2011-12 campaign in Germany with the Hamburg Freezers.  He returned to North America in the Wild system the following year.  Curry's first season under the Wild umbrella saw him go 17-11-2 with a 2.80 goals against average and .910 save percentage in 32 games with the Solar Bears and also play one game for Houston.

Before turning pro Curry was a standout at Boston University, where he went 59-29-15 with a 2.07 goals against average, a .923 save percentage and 13 shutouts in 107 games over four seasons.  As a senior in 2006-07, he was named a finalist for the Hobey Baker award and earned First Team All-American honors after going 17-10-8 with a 2.01 goals against average, a .921 save percentage and seven shutouts.  The All-American selection was Curry's second in as many seasons- he was a second team choice as a junior while helping the Terriers to the 2006 Hockey East regular season and tournament titles.  Curry also helped propel B.U. to three straight NCAA tournament appearances.

Milner, 24, has gone 3-2-0 with a 2.77 goals against average and a .912 save percentage in five games with the Mallards this season.  Last night Milner stopped 22 shots in regulation and overtime and made four saves in the shootout as the Mallards came from behind for a 4-3 shootout win over Tulsa Oilers.

The 6' 1", 197-pound Pittsburgh native returned to the Mallards from Iowa Sunday after serving as the Wild's back-up goaltender in three games following a November 11 call-up.

The Mallards return to action tomorrow night at 7:05 p.m. on home ice against the Rapid City Rush.  Tomorrow evening also brings the return of $1 Dog/$1 Beer Night presented by 97X and MetroLINK.  Fans can enjoy $1 hot dogs and beers from iWireless Center concession stands during all Friday home games.  97X will follow in the spirit of the evening by presenting hot dog-themed intermission entertainment.

Tickets for all remaining Mallards regular season home games- including tomorrow night's tilt- are on sale now at the iWireless Center box office, Ticketmaster outlets, ticketmaster.com and Ticketmaster charge-by-phone toll free at 1-800-745-3000.  The box office is open weekdays from 10:00 a.m. to 5:30 p.m., Saturdays from 10 a.m. to 2:00 p.m. and game days from 10:00 a.m. until the start of the second period.  Tickets are available for $10, $16, $20 and $28.

Washington, D.C. - Congressman Dave Loebsack released the following statement this evening in response to the President's action on immigration.

"There is universal agreement that our immigration system is broken and is in need of reforming. It isn't working for families, businesses or rural America. But for nearly two years, House Republicans led by John Boehner have had a chance to address this issue and have refused to put any comprehensive, bipartisan legislation on the floor. At the same time, bipartisan Senate-passed legislation, while not perfect, awaits action in the House. It is unfortunate that Speaker Boehner has catered to the demands of the extreme Tea Party members in his party and has simply refused to act.

"I have concerns about the President acting without Congressional approval and would have preferred that Congress address this issue. But it has become increasingly clear that the extreme Tea Party faction will not allow any vote on immigration legislation. It is my hope that this action by the President will provide the impetus necessary to spur the House to act on legislation that secures our borders, enforces the rule of law and ensures accountability for those who came here illegally while not tearing apart families who have been here for many years. I am committed to working with anyone on either side of the aisle to advance a serious proposal that will finally fix our broken immigration system."

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(DES MOINES) -Today, Governor Terry E. Branstad approved an emergency proclamation suspending the regulatory provisions pertaining to hours of service for drivers of commercial motor vehicles transporting diesel products.

Pipeline and refining outages affecting the supply of diesel products, coupled with the abrupt and early drop in temperatures, have resulted in low inventories of diesel products in Iowa and the upper Midwest. The Governor's emergency proclamation suspends regulatory provisions of the Iowa Code pertaining to hours of service for crews and drivers delivering diesel products.

The proclamation is as follows:

WHEREAS, because of pipeline and refining outages affecting the supply of diesel products in Iowa and throughout the upper midwest, coupled with an abrupt and early drop in temperatures throughout the state, the people of the State of Iowa are faced with extremely low inventories of diesel products; and

WHEREAS, this shortage of diesel products has a serious impact on the flow of critical goods and services throughout the State of Iowa; and

WHEREAS, the limited suspension of certain hours of service regulations for drivers of commercial motor vehicles transporting diesel products in our state will increase the amount of those products transported throughout the State of Iowa, thereby reducing the damaging effects of this shortage; and

WHEREAS, these conditions threaten the peace, health, and safety of the citizens of the State of Iowa and accordingly provide legal justification for the issuance of a Proclamation of a State of Disaster Emergency pursuant to Iowa Code § 29C.6 (1).

NOW, THEREFORE, I, TERRY E. BRANSTAD, Governor of the State of Iowa, by the power and authority vested in me by the Iowa Constitution Art. IV, §§ 1, 8 and Iowa Code § 29C.6 (1), and all other applicable laws, do hereby proclaim a State of Disaster Emergency for the entire state of Iowa and do hereby ORDER and DIRECT the following:

SECTION One. I temporarily suspend the regulatory provisions of Iowa Code § 321.449 pertaining to hours of service for crews and drivers delivering diesel products during the duration of this disaster, subject to these conditions:

A.     Nothing contained in this Proclamation shall be construed as an exemption from the controlled substances and alcohol use and testing requirements under 49 CFR Part 382, the commercial drivers' license requirements under 49 CFR Part 383, the financial responsibility requirements of 49 CFR Part 387, or any other portion of the Code of Federal Regulations not specifically identified in this proclamation.

B.     No motor carrier operating under the terms of this proclamation shall require or allow a fatigued or ill driver to operate a motor vehicle. A driver who informs a carrier that he or she needs immediate rest shall be given at least ten consecutive hours off duty before the driver is required to return to service.

C.    Upon the request of a driver, a commercial motor carrier operating under this proclamation must give a driver at least thirty-four (34) consecutive hours off when the driver has been on duty for more than seventy (70) hours during any eight consecutive days.

D.    Motor carriers that have an out-of-service order in effect may not take advantage of the relief from regulations that this declaration provides under title 49 CFR § 390.23.

E.     Upon the expiration of the effective date of this Proclamation, or when a driver has been relieved of all duty and responsibility to provide direct assistance to the emergency effort, a driver that has had at least thirty-four (34) consecutive hours off duty shall be permitted to start his or her on-duty status hours and 60/70 hour clock at zero.

Iowa Code § 29C.6 (6).

SECTION Two. This state of disaster emergency shall be effective at 12:01 a.m. on November 21, 2014, shall continue for fourteen (14) days, and shall expire on December 5, 2014, at 11:59 p.m., unless sooner terminated or extended in writing by me. Iowa Code § 29C.6(1).

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