Engineering students show off their creations

Imagine a cross between and old-fashioned sewing machine and a tiny guillotine.

That’s the blueberry stem cutter Aidan Blanchard and his teammates produced for Higbee’s Berry Farm & Nursery. In the process of cloning blueberry bushes to sell to other farmers, the woman who owns the New Ross operation was getting carpal tunnel syndrome and arthritis in her wrists from using hand shears to snip tens of thousands of stems over a two-week period.

“What we were tasked to do was come up with something for them to use instead of hand shears,” Blanchard said Thursday at the Capstone Conference that gives Dalhousie University engineering students who are about to graduate a chance to demonstrate their problem-solving skills.

The fifth year co-op student from Herring Cove and four other would be mechanical engineers looked at several different designs before coming up with their motorized cutter.

“We actually finished it yesterday, and as of yesterday, it does cut,” Blanchard said.

“Their prime time is starting up in a couple of weeks. Hopefully we’re going to do some reiterations. We might need to re-spec the motor and get a large one. So we’re going to do some little re-designs now that we have something that works and we can start properly testing it.”

Cheaper snow removal

A few stalls over in a conference room at The Westin Nova Scotian, Tate Linzel described how his team worked with Dexter Construction’s winter maintenance operations group to come up with better ways to pay snow plow drivers, track any damage they cause, and figure out how much it costs to clean up after a winter weather event.

The fifth year industrial engineering student helped develop four different methods of paying drivers to reduce Dexter’s costs and retain employees throughout the years.

By using a linear tiered salary, Dexter would see an average cost saving of 6.5 per cent, Linzel said.

Their damage-tracking tool has drivers inputting their oopsies into an Excel form. They took that data and linked it with Google Earth to map problem areas where drivers might need more training.

“The last one that we worked on is a cost per winter weather event, which is a performance metric for them,” Linzel said. “We took three major costs — their labour, equipment, and material costs — and we broke them down.”

From that, Dexter can investigate mysteries, for example, where there was no snow, but costs spiked. Turns out, in that case, the company spent a lot of money on salt and sand because temperatures were hovering around the freezing mark.

“There was no precipitation, but it was still icy out, so they had to send trucks out and put down salt, which costs a lot,” said Linzel, whose team will present their results to Dexter early next week.

A cardiovascular pump

If the winter weather’s got your heart pounding, a cardiovascular mimicking pump might play a role in your future.

“Basically it’s a pumping system that is supposed to mimic the heart flow throughout the body,” said Renae Verboom, part of a team of fourth year mechanical engineering students.

Their client, Clifton Johnston, an associate professor of mechanical engineering, is researching stents and wants to test how well they work in the body.

“There are stents (placed by surgeons) on the inside of arteries and on the outside,” Verboom said. “The ones on the inside remove blockages. And the ones on the outside are for aneurisms. So they basically go around an artery and if the blood vessel is too big, they’ll kind of encirculate it so that it can be the correct size and so it won’t blow up.”

The pump uses a motor and a pumping system, with a flow meter and pressure sensors that provide feedback on how well the system is working.

“The pump is the most crucial part of the model,” she said.

Verboom’s team looked at different kinds, but settled on a gear pump because it can rotate in both directions. “Because hearts have negative flow and it also is very easily programmable.”

Gluten-free beer

Anyone who wants to toast that solution might want to do it with a gluten-free beer.

That’s where Susan Barney and her team of four chemical engineering students came through with a buckwheat ale recipe they developed in the lab.

“Currently beer is typically made with barley, which is not a gluten-free product, so (people with Celiac disease) can’t consume it,” Barney said.

“So we were looking at making 100 per cent buckwheat beer, which is 100 per cent gluten-free and can be consumed by Celiacs.”

Buckwheat tastes better than sorghum or rice, which are both gluten-free alternatives to brewing, she said.

“A lot of the industrial scale (breweries) only use 50 per cent grain, and then they just fill up the rest with sugar because that’s what you actually ferment. The yeast uses that sugar to produce ethanol and CO2.”

The sugar is a cheap substitute to using all grain, Barney said.

Her team tried six different grain-to-water ratios before coming up with their recipe, which produces a beer with an alcohol content ranging from 4.36 per cent to 5.33 per cent.

Alas, they haven’t tried drinking it yet. “We did get to ferment it, but it wasn’t sterilized. It still had proteins and stuff in it, so we weren’t able to actually drink it. But when we opened it after fermentation, you could definitely tell that it was beer.”

While they didn’t have a client in the first place, Barney’s team plans to pitch the recipe to real brewers.

“We costed out some equipment that a brewery could (use) to retrofit their current system to be able to brew our product,” she said.

“There’s two pieces of equipment and about $37,000 is the capital investment to do it. This is based on a 20-hectolitre brewery. If they brew three brews a year, they can pay back their investment within one year.”

There are over 300,000 Canadians with Celiac disease, she said.

“And the numbers are rising due to increased awareness and testing,” Barney said.

“Then we also have a certain number of people who just choose to live a gluten-free diet. So there’s definitely a market there.”

Robotic fingers

If you need a hand hoisting that ale, Abigail LeFrank and her team of mechanical engineering students have designed a set of wearable robotic extra fingers for grasping compensation.

“This would help someone who’s had a stroke and can no longer grasp objects,” she said.

Strokes interrupt the blood flow in a person’s brain when blood vessels rupture, said Neil Chambers, who’s on the same team.

“Depending on where in the brain the vessels rupture they’ll lose the ability to do some sort of process,” he said. “So if it happens in the back of the brain, they may have their hands become spastic – just tight as a fist – permanently. So they won’t be able to grasp anything with that hand anymore,” Chambers said.

“The purpose of the device simply is to allow them to grasp objects again. So whether they have one or two spastic hands, they’ll be able to push the buttons on the top of the device (with their other arm) and then the fingers will retract and close upon the object that is in front of them.”

The robotic fingers, which they developed for one of their professors, are quite comfortable to wear, LeFrank said.

“We’ve got some pretty thick foam (on them),” she said.

They’ll be powered with worm gear motors attached to cables. “So when you push the close button, the motors will wind in the cable, causing the fingers to close,” LeFrank said. “It operates much in the same way that your regular finger would with tendons.”

They tested the robotic fingers ability to grasp objects ranging from the size of a pencil to a milk carton, she said. “So it’s meant to restore everyday tasks.”

While that project could reduce difficulties for people who suffered injuries, others were aimed at preventing them.

Ergonomic grape picking

Alexis Dunphy was one of four mechanical engineering students tasked with solving a problem for One Ten Vineyards, located just north of Wolfville.

“Due to the low fruiting heights of grapes, workers are forced to either work hunched over, kneeling, or sitting on buckets while they’re going down the vines, which causes a lot of strain on the body and is going to cause prolonged injuries,” Dunphy said.

The owner wanted his workers to be in a more ergonomic position while moving down the vines, she said.

“He’s a small vineyard owner, only having three acres, and (the solution needs to cost) below $500,” Dunphy said.

Using a tractor seat already designed for efficiency and comfort in the working environment, her team built a low cart with three wheels people could use to harvest grapes.

“You sit on it and push backwards like you would while moving around in a computer chair at home,” she said. “We wanted something that allows you to stretch and that encourages you to constantly be moving.”

Once users reach the vine they want to work on, they engage the brake, and then physically turn ninety degrees to work at the vine. “Picking, pruning, leaf pulling – all of that is within about the same range.”

The height of the seat can be adjusted, she said.

“That way people of different heights can work comfortably so their legs are in the position they like,” Dunphy said. “And it also allows you to move between different grape species that have different fruiting zones.”

They built a wooden prototype and are now working on an aluminum version.

“We are hoping to do testing at the vineyard,” she said. “That depends on if this snow ever leaves.”

Reducing wait times

If your knees wear out before they get it working, April MacHattie’s team of four industrial engineering students are working on ways to shorten the wait for replacement surgery.

“Our problem is that Nova Scotia has the longest wait times for knee replacement surgery,” she said.

Her team created a computer model to show the system as it exists right now. Then they proposed some solutions for the Nova Scotia Health Authority to decrease the wait times.

“There are two wait times. The first one is once you see your family doctor, you have to wait until you actually see a surgeon to see if you (need) surgery or not,” MacHattie said.

If someone requires surgery, they go on a second wait list for that, she said.

“We’re hoping to implement this new assessment clinic where instead of going to see the surgeon for your first consult … you go to this assessment clinic.”

Patients at the clinic wear a gait assessment tool that looks like a knee brace while walking on a treadmill. It employs cameras that provide data on whether the surgery is needed, she said. “There are trials going on right now (at the Camp Hill Veterans Memorial Building of the QE II Health Sciences Centre) and it’s about 89 per cent accurate.”

That should take patients who don’t need surgery off the wait list, rather than waiting a long time to see a surgeon to hear the same news, she said.

There are about 600 patients right now just waiting to see a surgeon for the initial consult, she said.

“Over a 10-year period, with this implemented, it would be down to less than 50,” MacHattie said.