Technology pulsates through heart and legs

Photo: Robot with a big red gripper

However, those robotic applications for working on human beings destined to become more important, must meet the highest safety standards.

Robotics is one of the oldest dreams of mankind and was always meant to make the impossible possible – at least in cinematic realization of science fiction and in literature. Since the first real confrontation between humans and robotics in the thirties during the New York World’s Fair however, a lot of time has passed. Back then humanized systems like the talking robot “Elektro“ and its later developed companion “Sparky“ the robot dog were a big attraction. Today the integration of technical solutions inside and on the human body is intriguing. Especially in surgical sciences, minimally invasive robotically-controlled procedures have been particularly convincing in the past few years. Significant developments have also taken their place in medical prosthetics and implant research.

A robot for your heart
A completely implantable cardiac assist system will be able to help patients with severe cardiac insufficiency in the long run, since up to now they only have limited treatment options available to them. Now researchers at the German Aerospace Center have developed a first alternative to heart transplants by way of a special propulsion technology on the basis of lightweight robots. By means of dual-chamber technology, the system supports the heart with pulsatile volumetric flow. The artificial heart pump is combined with a so-called DLR-TET. An implanted coil sends data and energy to the implant.
Whether the pumping system will reliably pass the crucial test in the human body however, is still the question. Especially when it comes to a highly sensitive and vitally important organ like the human heart, all possible complications should be ruled out beforehand. So far, the promising system has only been tested in acute and constant load experiments and on animals.

“Every time a symbiosis between human beings and technology occurs, we must scrutinize this kind of equipment with a technological impact assessment. We rate the system based on different criteria. For example, the user must not be put at risk and should not overrule him“, adds Professor Michael Decker, Deputy Director of the Institute for Technology Assessment and System Analysis (ITAS) at the Karlsruhe Institute of Technology (KIT).

First attempts at walking thanks to the exoskeleton
An entirely new robot system is being further developed at full speed by several companies all over the world: the exoskeleton – an external skeleton that is meant to assist mobility impaired people in walking.

This is a structure that’s modeled after a natural skeleton. Researchers integrated ankle and knee joints on which motors have been attached that power the individual skeleton parts, so the patient is being walked by the system. The only people considered for using an exoskeleton, are those which no longer have any active muscle function in their legs, but can still sufficiently move their arms. The patients hold walking crutches which in turn have built-in switches. The user then initiates the corresponding step by applying pressure on the handle of the walking crutch. However one basic question remains: how high is the performance of such a battery-powered system?


Photo: skeleton

Doctor Rüdiger Rupp, Chief of the Department of Experimental Neurorehabilitation at the Spinal Cord Injury Center, University Hospital Heidelberg, Germany, explains:”It varies with each system how long the batteries will last. The manufacturers keep a very low profile when it comes to this issue. However, this is a crucial criterion for user acceptance of these units. In our experience, the equipment should be operational for about eight hours. However, this largely depends on the type of use. “

If a patient wants to use the exoskeleton for an entire day that lasts about eight hours and wants to go for a walk for example, the battery capacity will barely be enough. Frequently the current exoskeleton versions are not operational for an entire day and have to occasionally be recharged.

The initial always positive reactions by paraplegic patients sometimes ignore one component: the robotic walker is not the magic cure for all patients. “The systems are suited for paraplegics with very deep lesions, where only the legs are being affected. All of the machines walk according to a programmed pattern. Consequently the patient has no way of controlling the machine under his own strength, at least as far as the current exoskeletons are concerned, “ Rupp emphasizes. That’s one important factor to not raise any unrealistic expectations.

As much as these developments in all areas of the public health sector raise early hopes and open up new possibilities for the industry: the safety of patients who use such robotic systems is an important part of the long-term success in the real world. Whatever possibilities still remain open, will require close examination for both systems. After all, the present state of studies is still in its beginning stages.

“So far the model was tested by the manufacturer in a study with ten patients; that’s the latest from this year’s Paraplegic Conference, to find out to which extent patients are actually able to control such a system. This was not about therapeutic effects,“ says Rupp.

At the moment predominantly rehabilitation clinics utilize the system to treat patients. But there is no reliable study data yet on how far the systems provide a therapeutic benefit. We may be anxious to see the further development.

Diana Posth