The Zeus bionic limb is yet another solid contestant in the bionic arm/hand market. Strong and durable with a lift capacity of 35 kgs and one of the highest grip forces in the industry, it is also deft enough to support a wide variety of tasks.
A Quick Look at Zeus
This first short video shows Zeus being used in a variety of tasks around the house:
By contrast, this next video shows Zeus participating in all the steps required to make a meal. Notice how the wearer uses his Zeus to turn the door key and also how he holds the knife:
Now that you’ve seen Zeus in action, let’s dive into some of its more interesting features.
The Zeus Bionic Limb’s Key Features
Grip Patterns & Control System
In theory, the number and types of tasks that a bionic hand can perform depend on the number of grips that it supports. In the current bionic arm/hand market, this ranges from a low of 6 to a high of 36.
Numerically, Zeus falls in the middle of the pack with 12 standard grips plus 2 more that are user-configurable. Here is a quick look at some of its core grips:
There is a reason that we like to focus on core grips. According to multiple scientific studies, users only use a few core grips for most tasks, so having a high number of grips is not that important. What’s important is how well a bionic hand performs its core grips.
In this regard, Zeus offers a few valuable enhancements. First, it automatically detects the thumb position and limits the available grips accordingly. Also, as each finger closes, it stalls as soon as it meets a certain level of resistance. This allows Zeus to intuitively conform to the shape of each object that it grasps.
For example, when picking up a wine glass, the thumb, index finger, and middle finger all stop closing once they meet the resistance of the glass bowl. But the ring finger and pinky continue closing until they encounter the stem. This mirrors the way natural hands work and results in better, more adaptable grips.
Of course, none of this matters if a user can’t precisely control a bionic hand. To control Zeus, users must move the muscles in their residual limb as if they are:
- flexing their wrist;
- extending their wrist;
- clenching their hand into a fist.
Myoelectric sensors placed against the skin of the residual limb detect these movements. A control system then translates them into commands for the bionic hand, typically to open or close the hand. Exactly which fingers open or close depends on the selected grip.
This is collectively known as a myoelectric control system — the system currently used by all commercial bionic hands.
There are some challenges when using this type of system. For more information, see our article, Finding the Right Myoelectric Control Systems.
Zeus uses the Element Sensor System from Infinite Biomedical Technologies (IBT) as a key part of its myoelectric control system. We will soon be publishing an in-depth story on IBT’s technology because they are making a concerted effort to improve myoelectric control. Once we complete the IBT article, we will update this article accordingly. In the meantime, here are the key benefits of Zeus using the Element Sensor System:
- digital signal processing;
- improved noise reduction;
- a lower physical profile;
- wireless setup and adjustments.
We suspect that this system is superior to using standard suction socket myoelectrode systems but we are attempting to confirm this through independent sources. Either way, we will update this section when we learn more.
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To change a grip, users must make one of the three muscle movements described earlier combined with a full muscle contraction. They can do this to:
- loop through the available grips in sequence
- pair specific grips with specific actions
Manual Thumb Rotation
Zeus does not come with an electronically positioned thumb. The thumb does open and close electronically, and it has a built-in sensor to detect its position, which it uses to determine available grips. But users must manually rotate the thumb into an opposing or lateral position.
This is not a major drawback. Myoelectric hands typically require some form of preparation before performing a task, such as selecting an appropriate grip. In most instances, users will intuitively rotate Zeus’s thumb into position with their free hand. However, there are some cases where this is not convenient, such as when both hands are needed for a task.
In Zeus’s case, this is a trade-off for its grip strength and robustness. To rotate Zeus’s thumb would require a heavier motor, which in turn would increase the hand’s weight. It would also complicate the grip change mechanism, which Zeus has tried to make as easy as possible for users.
However, in a market where several hands now offer electronic thumb rotation, we do view this as a slight competitive disadvantage.
Proportional Speed Control
As with most myoelectric hands, the Zeus bionic limb offers proportional speed control. This allows the user to change the grip speed and strength just by controlling the strength of muscle signals.
Lift Capacity & Grip Strength
Zeus offers a lift capacity of 35 kgs, which puts it in the upper tier of the industry. It also offers a grip force of 152 newtons, which is the most we’ve seen for any bionic hand. By comparison, natural hands exert roughly 70 newtons of force for typical daily activities. Put another way, you will never lack grip strength when using Zeus.
The Zeus bionic limb offers several features to enhance its durability. Its fingers are compliant, which reduces the risk of finger breakage. Its palm uses a combination of hard and soft material for reduced weight and lateral shock absorption. And if you do happen to damage the hand, its modular design makes for a fast and easy repair that can be performed at a local service center.
The standard Zeus kit comes with thin, flexible battery cells that, combined with IBT’s low-profile sensor system, supports the creation of streamlined arm sockets.
Not only does this make the socket more attractive for the wearer; it also makes fabrication easier for the prosthetist.
The Zeus Bionic Limb comes with 10 different silicone glove color options that can be fit to the hand.
Zeus is also compatible with the Whizzlink system from Glaze Prosthetics. This means that a user can personalize his or her bionic limb with different levels of customization and finish.
Suitable for Both Above- and Below-the-Elbow Solutions
Another trend in the bionic arm/hand market is a move toward modular solutions, where separate components can work together to provide the required prosthesis.
Zeus is no different. It can be used with a fitted shell for below-the-elbow limb differences, or in combination with bionic elbows and/or shoulders to form a complete bionic arm.
According to our information, the Zeus bionic limb sells for between $10,000 and $20,000 US for a typical below-the-elbow solution, including all prosthetist fees.
For a complete list of prices for other bionic hands, please see our Bionic Hand Price List.
Considerations Before Buying the Zeus Bionic Limb
We cannot comment on many aspects of the Zeus bionic limb in the field, as it is still relatively new. As soon as we find independent user reviews, we’ll include them in this article.
What we can say is that, at $13,000 to $15,000 USD, prospective users should at least take a look at this device, especially with its focus on improved myoelectric control.
We also have a very good opinion of its founder and CEO, who has been as open and transparent with us as we could ask — a good sign with any company.
For a list of competitor devices, see All Bionic Hands.
For a complete description of all current upper-limb technologies, devices, and research, see our comprehensive guide.
Click here for more information on Aether Biomedical.