Training robots revolutionize therapy

Image © Dynamic Devices

Image © Dynamic Devices

When two Swiss robotics engineers developed a new computer-controlled leg press, they were thinking of athletes as their main target audience. Then it turned out that their Soft Robotic Training was surprisingly effective in the rehabilitation therapy of injuries and other physical conditions.

The device has little in common with the leg presses you see in gyms. Of course there is a seat and two pedals, but that is where the similarities end. Taking a seat on the Allegro (for Adaptive Leg Robot) means entering into the care of a unique, soft-robotic training partner. It is equipped with state-of-the-art industrial drive and safety components and a learning computer system. Human and machine work closely together – with astonishing results.

A pneumatic muscle is the core
Allegro is the brainchild of robotics experts Max Lungarella and Raja Dravid, founders of the company Dynamic Devices AG. They developed the first Allegro prototype in 2007 at the Artificial Intelligence Laboratory at the University of Zurich.

Their goal was to build a high-tech device for athletes, a highly dynamic machine that monitors and analyzes all workout sessions and makes suggestions for the next exercise. The core of the device is a pneumatic muscle that is able to deliver large forces to the pedals very quickly. This enables the machine to be used for a variety of challenging exercises.

Example: By pressing or pulling in with their legs, the user has to stay close to a line displayed on the screen. At the same time, the computer amplifies the effective forces, either gently or in the form of impacts. The user has to compensate these forces continuously, which is demanding but extremely effective. Not just the body is trained, but also the brain. “Our system supports this kind of dynamic interaction”, says Max Lungarella. The concept works even better than the two developers had at first imagined.

“Our system supports the dynamic interaction between brain and body.”
Max Lungarella, Dynamic Devices

More or less by chance, the two discovered that their training system had great effects on patients with neuro-muscular disorders or orthopedic conditions. On the Allegro machine, a number of patients were able to move their legs again in ways that didn’t seem possible. Stroke patients also made great progress in the restoration of their motor skills. These effects have now been corroborated in studies – a fact that motivated the developers of the softrobotic training device to focus primarily on rehabilitation. This is where maxon motors enter the stage.

In order to certify the Allegro as a medical device, it needed a critical safety feature: an adjustable stop that prevents the press from going past a certain angle. This is to protect the patient, especially those who are no longer able to fully bend their knees. A brushless EC 45 DC motor takes care of the individual positioning of the safety stop. Absolute reliability is an important, if not the most vital criteria for the drive. “With a maxon motor, we can be certain that this requirement is being fulfilled”, says Lungarella. Other important points include the compact design and integrated electronics of the flat motor.

Successful combination of drive and controller

Another maxon flat motor, an EC 90 with an outside rotor, is in charge of automatic seat positioning. Dynamic Devices combined the brushless motor with a planetary drive and an ESCON 50/5 servo controller. maxon drives are a key component of this training device, providing comfort and safety to the patient.

Success through a playful approach
Despite being a relatively new company, Dynamic Devices has achieved considerable success. Engineers, scientists, physicians, and therapists have collaborated to create a training device that gives many patients new hope for an improvement of their motor abilities. The decisive factor is the training aspect, which was traditionally relegated to a relatively minor role in rehabilitation therapy. If you sit down on the Allegro, you can expect to be challenged. If users are motivated to become better and score higher, their performance improves faster. Motivation is important, and that is why Dynamic Devices focuses on a playful approach. When patients use the pedals to control a simulated penguin sliding down a hill on its belly, trying to score as high as possible, they almost forget about the physical effort.

Some hospitals and rehabilitation centers are already using the new robotics-based training with more soon to follow. The next step is an expansion into the entire Eurozone. In addition, Max Lungarella and Raja Dravid are working to make their soft-robotic training device even more intelligent.


A brushless DC motor for demanding operating room applications

A sterilizable EC-4pole 30 from maxon motor

A sterilizable EC-4pole 30 from maxon motor

A sterilizable EC-4pole 30 from maxon motor

maxon’s new brushless electric motor, the EC-4pole 30, delivers high torque (106 mNm) and is sterilizable – a perfect drive for hand-held surgical tools.

Swiss drive specialist maxon motor has developed a robust brushless DC motor for hand-held surgical tools: the EC-4pole 30. Featuring two pole pairs, this DC motor provides a nominal torque of 106 mNm and an output of 150 W. It has a hermetically sealed rotor, meaning that it can withstand over 1000 autoclave cycles.

Need to operate at overload? No problem!

The EC-4pole 30 is equipped with the special ironless maxon winding, which makes it highly efficient. Another key feature is that the torque and current behave linearly and the drive can be overloaded. It is available with an optional Hall sensor, as well as with a hollow shaft with a diameter of up to 4.1 millimeters.

With the EC-4pole 30, engineers get a first-class drive for surgical hand tools that work flawlessly under the tough conditions of operating rooms.

maxon offers a complete line of dc brushed and brushless motors, gearheads and controllers. Contact us to help find the right solution for your application.

Brushless DC motors for down hole and directional drilling.

Directional Drilling

Directional Drilling

The recovery of petroleum and natural gas requires constant innovation and improvement of technology. This technology used for deep drilling processes are exposed to extreme environmental conditions. Temperatures of 200+°C, high pressure and extreme shock and vibration. Brushless DC motor technology from maxon motor is utilized in various drilling applications, hydraulic valve control, communication mechanisms and measuring instrumentation.

Today over 85 percent of the world’s energy use is based on fossil fuel sources such as coal, oil and gas. However, reaching these resources requires the need to drill deeper than ever before which is not a simple exercise. Down hole deep drilling equipment opens the possibility of recovering resources from depths greater than 2.5km. Recent developments allowing down hole drilling equipment to be directionally controlled has given access to formerly inaccessible oil reserves. Now drilling to 5km down and 11km across is even possible.

Extremely tough environmental conditions are commonplace globally for drilling equipment, the demands on the drill head in particular are at their highest. Brushed and brushless DC motors need to withstand the intense vibration, pressure and heat. The heavy duty brushless DC motor range produced by maxon motor are not only designed for but are rated and tested to meet these conditions. Combined with new electronics technology they allow for improved control and monitoring of drilling procedures.

Mud flow power and more.

Using magnetic couplings a back driven motor becomes a generator. Using the mud flow for the drill turbine the brushless DC motor power is then harnessed for localized electronics in the drill head avoiding the need for batteries. The drill head position can also be detected and adjusted on the fly. This process is called Measurement While Drilling (MWD). This technology converts sensor data into pulses that are transmitted to the drilling platform. maxon heavy duty motors can actuate the mechanism, forming the communication pulses. maxon heavy duty DC motors also actuate hydraulic valves within the drill head.

Heavy Duty Brushless DC Motor. © 2012 maxon motor

Heavy Duty Brushless DC Motor. © 2012 maxon motor

maxon heavy duty motors are also available with corresponding gearboxes. The gearboxes are manufactured with the same extreme operating environments in mind. The applications typically require elevated torque for very low duty cycles. For example: Generating the mud pulses and actuating the hydraulic valves. A unique feature of the heavy duty gearbox is the through holes in the gear housing. These are ports that allow the gearhead to be submerged in oil and they facilitate the possibility for oil to circulate through the gearbox and provide elevated heat-sinking. The heavy duty DC motor also contains the oil ports and may also be used submerged in oil or in free air. The gearmotors are manufactured entirely without structural adhesives giving it the capability of withstanding extreme temperatures. This is also of particular importance when using the motor in vacuum conditions avoiding the contamination of the vacuum via outgassing. The heavy duty motor range is designed to withstand temperatures over 240°C at pressures up to 1,733 atmospheres. They can withstand vibrations to 25 Grms, impacts to 100 G.

High efficiency DC motors at great depths
The maxon heavy duty motor range features efficiencies of up to 88% in air and over 70% submerged in oil. This makes it an ideal solution for any extreme environment such as aerospace and heavy industry. They have zero cogging making them easy to control and suitable for precise positioning.

maxon’s ESCON Controllers

Roger Hess, Sales Engineer, discusses maxon’s line of ESCON motor controllers. These controllers were designed for dc brushed and brushless motors. You can configure the drive using maxon’s ESCON studio.

High performance drive in a small package

maxon's NEW brushless EC4mm motor and gearhead

maxon’s NEW brushless EC4mm motor and gearhead

maxon sets new standards in micro drives

maxon’s smallest DC brushless motor is only four millimeters in diameter and comes in two different lengths. Certified in accordance with ISO 13485, the new brushless micro drive is ideal for medical applications.

The EC 4 brushless DC motor is maxon motor’s ultra-compact solution to the market’s needs. As the smallest micromotor to come from the Swiss manufacturer, the EC 4 is only four millimeters in diameter. It is available in two lengths, with power ratings of 0.5 and 1 W. Equipped with an ironless maxon winding, the EC 4 stands out for its robust design, high power density, and energy efficiency.

EC4 measuring tool

EC4 measuring tool

maxon has the matching gearhead

Combined with the GP 4 planetary gearhead, the EC 4 becomes a compact drive for use in micropumps, analytic and diagnostic devices, and laboratory robots. Precise and reliable, it can adjust lenses, dispense fluids, or position sensing devices. All units meet the ISO 13485 medical standard, which makes this maxon micro drive the perfect choice for applications in medical technology.

maxon offers a complete line of dc motors, gearheads and controllers. Contact us to help find the right solution for your application.

Circulatory Support without Surgery for Heart Failure Patients

The cardiac pump is a mere 6 millimeters and 6.5 centimeters long. Image ©Procyrion

The cardiac pump is a mere 6 millimeters and 6.5 centimeters long. Image ©Procyrion

Intra-aortic pump powered by miniature brushless DC motors provides heart failure patients an aid to help hearts rest and heal.

Chronic heart failure patients draw hope from a new technology. A team of life science entrepreneurs in Houston, Texas has developed the first catheter-deployed circulatory assist device intended for long-term use. Procyrion, Inc.’s Aortix™ provides a minimally invasive treatment option for the more than two million chronic heart failure patients in the USA alone who are too sick for medication. This pre-clinical cardiologist tool dramatically reduces risks associated with circulatory support devices and enables treatment of younger, healthier patients before progressive damage occurs.

Assisting the natural function of the heart, the intra-aortic pump has been thoughtfully designed as an alternative to large, cumbersome surgical devices currently providing full circulatory support. Unlike these devices, Aortix provides minimal procedural risk. Measuring approximately 6 mm in diameter and 6.5 cm long, a cardiologist can deliver Aortix via a catheter in the femoral artery to the descending thoracic aorta. Once the catheter sheath is retracted, the self-expanding nickel-titanium anchors deploy to affix the pump to the aortic wall.

Aortix accelerates a portion of the body’s native blood flow within the pump and pushes it through fluid entrainment ports directed downstream. The jets entrain native aortic flow, transferring energy to the cardiovascular system and increasing blood flow to vital organs such as the kidneys. Additionally, in a model of chronic heart failure, Aortix decreased energy consumption of the heart by 39 percent, allowing the heart to operate more efficiently, encouraging cardiac rehabilitation and recovery.

The cardiac pump is a mere 6 millimeters and 6.5 centimeters long. Image ©Procyrion

The cardiac pump is a mere 6 millimeters and 6.5 centimeters long. Image ©Procyrion

Procyrion has been working with maxon for almost two years to develop a motor for this unique and demanding application. The basis for the Aortix device is a maxon EC6 motor with some customization including the electrical lead, shaft length, and bearing assemblies – all designed to make the pump durable and biocompatible. maxon also designed a high efficiency motor core for this application, which extends battery life and produces less heat so it doesn’t adversely affect the circulating blood. In addition, maxon is working closely with Procyrion to implement a magnetic torque drive, so the motor could be mounted inside a hermetically sealed chamber. This configuration eliminates the possibility of blood entering the motor core. The magnetically coupled pump arrangement is a method sometimes used for giant pumps in the oil field, but because of maxon’s breadth of experience across multiple industries, the company was able to help the Procyrion team successfully transfer this technology to a miniature scale medical application.

Each Aortix device consists of a small, continuous flow pump mounted within a self-expanding anchoring system. The anchored pump attaches to a flexible power lead, which can be tunneled to a desired transdermal exit site or to a Transcutaneous Energy Transfer (TET) system for subcutaneous implantation without an indwelling power lead.

Presently, the device can operate for over eight hours on a single battery pack. The external battery pack and control unit have been designed to be “hot swappable”, meaning the battery can be changed without needing to stop the device. A variety of charging devices can be used.

“Aortix reduces the heart’s energy consumption by 39 percent.”

The Procyrion team has also built a TET charging system that enables the battery to be charged wirelessly. This design has the potential to significantly reduce the risk of infection, common with other implantable heart pumps.

Because traditional assist devices replace heart function rather than support it, device failure can be fatal. With Aortix, a partial support device which doesn’t obstruct native blood flow, failure is not life threatening. Should the pump fail, the device can easily be retrieved and replaced in another minimally invasive, catheter-based procedure.

Kenshiro: Strong robot with 160 muscles.

Kenshiro humanoid robot, maxon motor ag © 2013

Kenshiro humanoid robot, maxon motor ag © 2013

The tendon-controlled humanoid robot created by the University of Tokyo has more than 160 artificial muscles and is the result of many years of experience. Around 100 brushless maxon motors ensures that the only 1.58 m tall robot has humanlike movements.

The University of Tokyo has developed a tendon-controlled humanoid robot that is capable of very realistic humanlike movements. He is called Kenshiro – named after a well-known Japanese hero who was made famous in the 1980s manga comic series. During the development of the robot, the Japanese scientists used the human anatomy as its focus to create an artificial human that looks as natural as possible. “We wanted to understand the movements and appearance of humans and replicate it as closely as possible in Kenshiro,” explains Professor Kei Okada. At a height of 1.58 m and weighing 50 kg, the robot matches the stature of a 12-year old Japanese boy.

To imitate the very complex human anatomy made up of approximately 640 muscles, the scientists equipped Kenshiro with the most important human muscles: 50 in the legs, 76 in the torso, 12 in the shoulder and 22 in the neck. This robot has the greatest number of muscles ever installed in a humanoid robot. Kenshiro’s 160 individual tendon-controlled “muscles” make many humanlike movement patterns possible. Kenshiro can move his arms, legs and torso. He still has to learn how to walk properly. How does a robot learn humanlike movements? It’s simple: demonstrate a movement, he will then imitate it.A simple learning method, implemented by means of open source intelligent software and a mechanical interface. Learning how to walk requires more.

Kenshiro’s “bones” are made of aluminum and, as is the case in the human body, are movably connected to each other. The biggest challenges to the scientists, led by Professor Masayuki Inaba, was the robot’s weight at 50 kg. A replica with the size of an adult would weigh approximately 100 kg which means a higher load, higher energy requirements and slower movements.

93 motors for 160 muscles
The researchers from the Jouhou System Kougaku Laboratory (JSK) of the University of Tokyo decided on a drive system by maxon motor. Kenshiro’s 160 muscles use 93 maxon brushless DC motors. For those special muscles as in the abdominal and thoracic, only a single motor provides the necessary drive and it is that of the maxon brushless EC 16 and EC 22 motors. These electronically commutated servo motors stand out with excellent torque characteristics, high dynamics, an extremely wide speed range, and their very long service life. Strong brushless motors are required for the muscle movements, therefore 60 W to 100 W maxon motors are used. Another important criterion for the motor selection was the temperature development of the motor. It is not possible to install a cooling system in the robot. According to Professor Kei Okada, it was therefore very important that the motors dispense very little heat.

JSK has been building various service robots and industrial robots since 1980 and today are focusing on their work with humanlike robots like Kenshiro. Just a

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