The Hippo Riders team of Rice engineering students has created a horse simulator for use by hippotherapy patients. From left: Amy Ryu, Erik Hansen, Jaime Gomez and Brett Berger. Photo by Jeff Fitlow

Rice University engineering students create equine simulator for hippotherapy

Some patients who could benefit from hippotherapy might not have access to a horse, due to geographic location, weather or affordability. Rice University engineering students have developed an alternative with their horse simulator, a robotic steed that can be ridden indoors anytime.

A team of students calling themselves the Hippo Riders created their device as a senior capstone design project at Rice’s Oshman Engineering Design Kitchen. The device will be demonstrated at the university’s annual Engineering Design Showcase April 14.

The simulator could give patients who use hippotherapy – also known as equine-assisted therapy — more opportunities to follow a regimen intended to help those with neurological or physical disorders like autism, arthritis, cerebral palsy and other ailments. The rhythmic, swinging motion is thought to enhance balance, coordination and motor development.

“It really does engage your core muscles and the ability to balance, and that’s what helps people,” said Amy Ryu, a mechanical engineering major.

“And it’s fun,” added teammate Jaime Gomez, also a mechanical engineer, after five minutes in the saddle.

Jaime Gomez tests the horse simulator. Photo by Jeff Fitlow

The robust prototype built with $1,200 in parts and a lot of labor began with help from Conroe-area physical therapist Janis Wells, who found her way to Rice through her work with team sponsors Harrell and Carolyn Huff. Carolyn is a Rice alumna.

“Janis was my physical therapist,” Harrell Huff said. “One day we were talking and I said, ‘Isn’t it expensive to have a horse and all this stuff? Why don’t y’all go to a bar and borrow one of those bucking broncos?’

“She said they can’t do that, so I said, ‘Would it be to your advantage to have a mechanical device that would substitute for a horse?’ I told her I knew a group that could probably design one.”

Wells told the team she wanted a way for patients to ride indoors during inclement weather or when the cost of reserving a horse was a factor. Ryu said physical therapy sessions with a horse can cost up to $150 an hour.

The resulting device differs from mechanical bulls and kiddie rides at supermarkets in the degree of control offered by three motors that can be programmed to operate independently and simulate a variety of gentle gaits.

“We can control the voltage and current output,” said Brett Berger, also a mechanical engineering major. “That lets us run a complicated control program for different motions.

“In the ride outside a grocery store, you put a quarter in and it moves back and forth a little bit,” he said. “But in our device, we can control the speed, the intensity and the type of gait, all routed through a microcontroller.”

“Because the motors are independently controllable, we can exert a huge degree of control over how the horse is moving,” added Erik Hansen, the team’s lone bioengineering major.

Amy Ryu and Erik Hansen make an adjustment to their robotic horse. Photo by Jeff Fitlow

The simulator can safely hold patients weighing up to 250 pounds, said the team members, who were advised by Rice engineering lecturer Matthew Elliott. “We designed it statically to hold much more than 250 pounds, and it won’t break until it goes up to 1,000-plus pounds,” Berger said. “But at 250 pounds, the motors stall. It’s just going to stop moving. The machine won’t continue, but it won’t break down.”

Motorized scissor lifts control the saddle height for each rider.

The students expect a new team of electrical engineering and computer science students will pick up the project next year and advance the control system to a more sophisticated level.

“We had to learn on the job how to weld, how to machine and how to build,” Berger said, noting that some computer programming was required as well. “But we don’t have the level of controllability we think our device is capable of. Moving forward, we expect another team will take it to the next level so that a physical therapist can use it in a clinic.”

“That’s going to require a more sophisticated control scheme than we have had time to learn how to do,” Hansen added. “A future team could get it to be like a horse walking through different kinds of obstacles or terrain.”

But the decorative, neighing hobby-horse head had better stay. Installing it was just too hard for the team to resist.

Rice University engineering students’ device makes composting easier

It’s good for crops, it’s good for water and, in the end, it’s good for people and the planet. Why would anyone not turn food waste into compost?

Rice University engineering students asked that question at the start of the school year and have spent the months since refining their answer.

The team known as (com)post-haste invented a device that sits under one’s sink and takes macerated food waste produced by a standard garbage disposal and sends it in one direction while liquid waste (including water) goes in another. Effectively, it simplifies the process of recycling garbage into a useful product while helping to protect water supplies.

The students make up one of more than 80 capstone design teams at Rice. Most senior engineering students are required to complete a project to graduate and are presented with a host of possibilities when they begin their classes in August.

For all the members of (com)post-haste, developing the device they call The BioBlend was a natural.

“I think for all of us this was the top choice,” said Kavana Gowda, who like all of her teammates is a senior mechanical engineering student. Other members are Christina Petlowany, Andrew Miller, Edgar Silva, Mitch Torczon and Ryan Yeh.

Rice University engineering students have invented a device to separate compostable materials from food waste processed by a garbage disposal. From left, Ryan Yeh, Christina Petlowany, Edgar Silva, Andrew Miller, Mitch Torczon and Kavana Gowda. Photo by Jeff Fitlow

The students have spent much of the last eight months working in the basement of Rice’s Oshman Engineering Design Kitchen, where they have installed an actual research kitchen – or at least the sink part.

The project is a partnership with NASA, which has an interest in such devices for outposts on the moon, Mars and beyond, and Chalmers University of Technology in Sweden, which pitched Rice on the project and intends to install The BioBlend at its Living Lab, where it will be tested alongside other emerging household technologies. Rice lecturer Matthew Elliott is the team’s faculty adviser.

“I think one of the major barriers to being eco-friendly in a variety of ways in the United States is people aren’t willing to put in any effort,” said Torczon of the device. “This doesn’t require users to change their behaviors. They can continue putting food down the garbage disposal, and once every couple of days take it out, just like taking out their trash.”

The difference is The BioBlend produces a moist, finely chopped form of waste that takes less time to turn to compost than regular garbage. Alternately, it can be used to generate biogas.

“One of the things our sponsors want to see is if they can make the device large enough to put in the basement of an apartment complex or a grocery store or restaurant, places with a ton of food waste,” Torczon said. “They could create a lot of biogas they could then turn around and sell or, if they’re in a restaurant, use themselves.”

“I think a family of four, using a biogas generator with their waste, would be able to make enough for them to cook with,” Gowda added.

Mechanical engineering student Andrew Miller makes an adjustment to The BioBlend prototype. Photo by Jeff Fitlow

Whether it’s used for compost or biogas production, the key to The BioBlend’s success will be its ability to keep garbage out of wastewater treatment plants, where it’s not only useless but also costly and complicated to remove.

The team’s research into separation techniques spanned sewage plants to hand-cranked tabletop devices for making jellies and tomato sauce. What they had in common was a circular strainer with a large screw in the middle that pushes solid waste along while allowing liquid to escape. Their own motor-driven, spring-loaded version has a failsafe to keep unwanted solids like ice from jamming the system.

A weight sensor tracks how full the bin is, a cutoff switch automatically trips before it overflows and a carbon filter helps quash odors and keep flies away from the compost.

The team has not ruled out giving The BioBlend Wi-Fi powers to alert users to its status via the Internet, Torczon said. They could just make it beep when full, but the students are wary that annoyed users would simply disconnect it rather than keep with the program.

The teammates had no problem finding a way to feed their creation. “One of the cool things about the project was digging once a week through the trash in the Rice serveries,” Yeh said.

“It’s caused me to reevaluate how much food I’m throwing away,” Torczon added. “Our sponsors said at the beginning they hoped it influenced our behavior.”