Exer­cise is impor­tant for patients suffering from paral­ysis. “Patients suffering from paral­ysis, such as stroke victims, lose muscle mass quickly if they remain immo­bile,” says Rovshan Makhmudov, a physi­cian and managing director of Orthorent, a Russian producer of reha­bil­i­ta­tion equip­ment based in Moscow. “That impedes their recovery and often leads to compli­ca­tions. Exer­cise is good medi­cine!”

Exer­cise machines like those made by his company can help. With the “Moto” model, patients prac­tice moving their arms and legs at three levels, with the elec­tric motor moving the limbs either entirely on its own or in support of the patient’s own move­ments. In the latter case, the motor exerts an adjustable resis­tance against which patients act to develop their strength.

Vari­o­Drive motor protects against muscle spasms

Orthorent’s rehab machines with elec­tric motors actively protect patients against muscle spasms.

An impor­tant require­ment was for the motor to work with the control system to reli­ably detect muscle spasms in the patient. In such cases, the motor has to stop the move­ment imme­di­ately to prevent injuries from occur­ring. “The Vari­o­drive Compact from ebm-papst was a safe solu­tion here since the control inputs for the motor elec­tronics can be used to slow down or stop the motor or to change its direc­tion of rota­tion,” says Makhmudov.

Another impor­tant crite­rion was the noise level. When several patients are using a rehab facility, high noise levels there mean stress for them. “Some of them already suffer from nervous condi­tions,” notes Makhmudov. “Quiet oper­a­tion is an impor­tant and often under­es­ti­mated factor in successful rehab.”

Frequency, not voltage

While devel­oping the Moto, Orthorent made use of tech­nical advice from ebm-papst in Russia. “First and fore­most, we’re doctors and not engi­neers. So we were glad to have ebm-papst as a project partner. All we had to do was name our require­ments and we got what we needed right away.”

An impor­tant require­ment was for the motor to be powerful yet light and compact as well.

Rovshan Makhmudov, Orthorent

For example, the Moto’s elec­tronics design called for a motor with a set value require­ment based on frequency instead of voltage, as is usually the case. The tech­ni­cians at the ebm-papst produc­tion site in St. Georgen made the neces­sary adjust­ments, simply assem­bling the circuit boards for the motor elec­tronics accord­ingly before sending the ship­ment to Russia. The shape of the output shaft was also an issue. Normally it has the shape of the letter “D” to keep it from twisting. However, the gears for the toothed belt that Orthorent wanted to use didn’t fit here. So the engi­neers changed the shape of the shaft while also suggesting another way to keep it from twisting.

The network doctor

Rovshan Makhmudov, Managing Director of Orthorent.

Makhmudov says, “One of our main require­ments was for the motor to be powerful yet light and compact as well, because our machines get trans­ported a lot.” Espe­cially since the Russian ministry of health launched the world’s first program for remote home rehab in 2015. Russia is a huge country, so it’s often a long way to the nearest rehab prac­tice. For many patients, being able to rent a machine and use it at home is impor­tant.

The Moto has an Internet connec­tion so that such patients can still get medical super­vi­sion in spite of the distance. Using detailed exer­cise proto­cols, doctors can follow a patient’s progress from their desks. They can even adjust the machine’s settings for the patient during an exer­cise session. The motor also plays an impor­tant role here, according to Makhmudov. “Many of our competi­tors’ prod­ucts still work with mechan­ical resis­tance. That makes them more diffi­cult for immo­bile patients to operate, and there’s no way to adjust their resis­tance para­me­ters via the Internet,” he says.

Here you can see Orthorent’s Moto working (Russian)