I am the engineer who developed the world's most intelligent prosthetic limb

Do you believe that humans will ever have the ability to create artificial limbs that outperform our natural ones? If so, why?

I think London Paralympic legacy showed the world that amputees can run a 100 meters faster than most of us can. Can they do it under 10s? my personal view is yes. But most of it is motivation, although hardware plays a part (Energy absorption & return and stride)!!
But beyond speed, naturally evolved human limbs are very hard to beat. The two legged person in actual fact is a perfect wheel, consuming the least energy to go from a to b.

How do you see the application of machine learning to the socket (above and below knee) design process? Nowadays it should be possible to build datasets with patients/residuum data, and use them to help create sockets that fit well. Thank you

Obviously you are one of us! Machine Learning is the focus of IR4 (Industrial revolution 4 or Industry 4.0) that is the key for many future engineering developments. The application of AI and machine learning is already being experimented with sensors as input which are applied to the socket interface. This is a critical area in lower limb prosthetic, the holy grail. Naturally most R&D engineers are thinking of how to solve the issues of every individual being different and every residual limb after amputation being different. Then there are changes in volume during the day pending on variation of activities. All these variation are the Perfect problem and scenario for machine learning to solve.

Thank you for the reply! I've worked in academia on socket design topic and investigated on the automatization of geometrical operations (load and off-load areas creation, circumferences reduction and so forth). One of the issues was to get enough data to build a good dataset (lots of cases needed). I suppose that at Blatchford you don't have this kind of problem :-) thanks

I guess we are lucky at Blatchford, as we also look after over 20000 patients, so access to users is easier for us. I am your studies will find its benefit in future development in this area. Please keep up the work and publish! (make sure you patent novel ideas/concepts)

Amazing work! Any chance you will be working on wrist/hand prosthetic in the future?

I have debilitating pain in both wrists, one fused and one about to be, mobility is very limited now and the surgery was suppose to subside the pain, it went from 8/10 to 7.5/10. I am young and can only imagine how bad it's going to get in 5-10 years. Maybe Ill have another option.

I am sorry to hear about your pain, and hope it gets better. We have not worked on upper limb for several decades, but other designers and manufacturers of artificial limb do work on upper limb and they have made fantastic developments for those who lost their limbs. In my view technology has a lot further to go. Every case of injured limbs are root causes are usually different, If it was me, I would keep working with my Doctor and look for solutions to keep the natural limbs and reduce the pain.

In reference to the Real Doll AMA yesterday, have you considered working with a company such as theirs to cover your prosthesis in a lifelike synthetic skin?

Edit: Link to the AMA of the creator and founder of Real Dolls. https://www.reddit.com/r/IAmA/comments/4y0uyn/i_am_matt_mcmullen_ceo_creative_director_and/

Yes but for different reasons. We have done silicon cosmesis and naturally would be very interested in life like synthetic skin to cover and provide more natural texture for the amputee. But it needs to be light weight and durable. For some amputees appearance is as important as function.

Just curious, but in my most recent bme classes on rehabilition engineering we discussed the importance of cosmetics for devices and there was a huge debate surrounding its importance. as someone in industry, where would you rate appearance in terms of the importance of any medical device to be used on a person (i.e. prosthetic, hearing aid, etc)

i personally think that for an external device, appearance is the second most important thing about a device, the first obviously being function. I say this because if your product doesn't look good then it won't sell, but i would like to know if my reason for saying so are based in truth or if i'm just thinking about it wrong. thanks for the AMA

I agree. Decades ago when I was taught rehabilitation of amputee, it meant restoration of function as #1 and Cosmesis as #2. However, with increased acceptance of physical disability by society (Thank you again London Paralympics), the appearance of the prosthesis is taking a new direction amongst younger amputees. So cosmetically shaped foam to match other is more routinely replaces with latest high tech look of composites, gloss paint finsh and for some an art as means to communicate.

Don't forget, the Deus Ex games go so far as to speculate that in the future, people will want prosthetic limbs, as they might confer advantages over biological ones.

Do you ever see that as a real possibility? Are there any little add-ons you think you might integrate with current models, like generating electricity through walking to charge a cell phone, or adding a flashlight to the wrist, laser pointer to a hand, compass or watch face to a wrist. . . that sorta stuff?

There is lots of research done on the regeneration of power in walking in artificial limbs. However at present the extra weight of the mechanism needed (due to loss of efficiency) to generate power, so far has proven not to be as effective to justify inclusion of extra mass. With power devices and back drivable motors, new battery technology, and alternative low mass low volume regeneration method, the balance may tip over.

Could you explain like I'm five how the prosthetic knows how to move? Seeing the advancing developments of prosthetics over time has always been fascinating to me. I can't wait to see what the future will bring! You guys do great work!

Legs move like a pendulum. and at one end connected the body which powers it by bending and straightening. That makes you go forward. The end result is like wheel. You can watch people walking from the side and if you really watch you can see the wheel turning with every time your foot hits the floor and then it takes off. A prosthetic limb is trying to copy this function to create the motion. At present our brain sends signals to the residual leftover part of the leg. When the user wants to walk this sets the limb into motion. In future this could be directly connected to the nerves.

What is the future of prosthesis? & Do you think engineers should have an open data concept to help push forward advancements?

Open source is the future for Big data in every area of engineering application. That helps to speed up development process and reduce cost of development. The more we can share advances, the quicker we can achieve next generation of prosthetic. In my view, this will use more advanced robotics and AI combined with situation awareness data. Hence smarter partnership with other field of engineering (e.g. autonomous car data) is a key to accelerate realization of the future.

I'm glad to see someone in the industry that shares that sentiment. I read a comment a while back by a user that had diabetes I believe, who's insulin pump kept malfunctioning. He was having problems obtaining any type of code for the device from the manufacturer, as he was wanting to make a fix for it a lot sooner than the manufacturer had plans to do so. Do you think it is a patients right to be able to obtain any code for devices that may be a part of them/help them survive? It all is such an interesting field of study! Thanks for your time!

It is a difficult one to answer. I can visualize the need to provide full access when we think about provision of devices to 7.9m amputees in Asia using additive manufacture (3D printing). However, in Western world (US,EU,etc) the medical devices regulation and the need to ensure safety of users, combined with current level of technology, may not permit such option. For example when we provide an App for amputees to select Cycling mode, we are empowering them to a degree and need to assess carefully their capability before hand.

Do you see prosthetics taking a more "biological" turn? Meaning, do you think we will see prosthetics covered in the wearers own skin or something similar in the future?

If by Biological you mean connected to your body, this is already happening in upper limbs and R&D phase in lower limbs. This is in the form connected to nerves via implant. However, I think the synthetic skin technology will advance enough to mimic natural skin without the need to maintain it as living organ.

What about artificial muscles?

Yes, we played with this and we should again. Air Muscles

Are these nerve sensor implants in the long, or the brain? Where can I learn more about the nerve implant technology?

Austrian have done some upper limb prosthetics connected to nerve nodes. The meeting below should have lots of papers on this for upper limb http://www.ispo.org.uk/events_meetings-V.html

Why did you decide to say that you developed the prosthetic rather than say that you were part of a team that did the work in the title?

Of course, It is absolutely a team effort, (and the title was short for simplicity). The team on Linx in fact is the entire R&D team at Blatchford (over 30 people). It integrated the various champions on different projects such as Knee, ankle, etc, and integrated beyond R&D team to pre production and manufacturing. Without any one of them Linx would not have been possible. We then have sales, and education team to thank for their effort to enable people to access the Linx. My role, was to conduct an orchestra and watch performance of the team. It was like watching a dance. That we will remember for a long time. You can see some of the members of the team in video below https://www.youtube.com/watch?v=gXNZCTH1q4I

What is the most difficult joint or action to reproduce artificially in your prosthetics?

Thank you for the AMA

Today, in legs, the ankle/foot which combines several joints and structures. The knee joint despite appearing critical is really intended to shorten the leg in a controlled way to minimizes head movement during walking. Naturally makes it easy to sit too!. I used to think that the Knee joint function was critical, but we know now that ankle/foot provide the key to stability, security, confidence and reducing risk of falls as well as reducing pain and discomfort at residual limb. So getting that right is the most important thing today. Better still, if the ankle/foot talks with the knee it is sure to provide abetter function. This what we set up to achieve with Linx.

Hello! I'm working on an upper-limb prosthetics project, so I'll have a few questions here...

Based on the few articles you linked, I'm getting the impression that the Linx acts almost independently of the user - it predicts the user's action and adapts for it to allow movement, but the user has no direct control over the device. Is that correct?

Is the device entirely passive, or does it have active dorsi/plantarflexion options, and would there be an advantage to one over the other?

What is the next limiting factor in improving lower limb prosthetics?

Career wise, how did you get to technical director?

Thanks!

The Linx does allow the user feel that they are in control. So if they walk slowly, it swings slowly, if they stop, it goes to standing mode, if they go down the ramp, it provides more resistance at knee and more break at ankle, and if they walk up the ramp, it provides more assistance at knee to straighten and toes to return energy. However the settings are customized and matched to users ability, weight etc, through calibration and fine tuning. So in that way the user does not feel the limb controls them and they can chose and influence their settings.

Linx is passive in as much uses the body mass to absorb and return energy. so it is classifies as passive. The active are when external power is directly used to move the joint or segment. The planterflexion phase (heel colliding with ground) is now considered to be more critical as its sets the motion direction and the rest will follow, So if we get that right in timing and control the rest is easier to manage in my view.

The Socket is the most important part. We are working on consistent suspension and dry skin and have advances a lot, ready for next level of integration of the whole limb interface to the body.

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Lots of questions to reflect and answer! I did a degree in Mechanical Engineering, then went to do a post graduate degree in bioengineering, then worked in the NHS, and then joined the R&D team at Blatchford. I always had a natural tendency trying to fix things and also wanted to do medicine. Events and circumstance mapped out the route and the journey.

The most expensive component of the prosthetic? in a low cost limb (for low activity) , or static prosthesis used for cosmetic application, the manufacture of socket which interfaces to the body (the residual limb after amputation) is probably the most expensive part. With advances in technology and application of robotics, due to low volume in the early years, the advance components are most expensive parts. Linx comparatively is expensive at present, but in time like most technologies I feel the prices should come down. Linx enables the user to walk on different terrains with more comfort, and changes its characteristic during ramp descent, stairs etc..

The Bluetooth is used during the adjustment at fitting stage only. The device is programmed for the way the individual walks using a laptop and matched the way the person control the limb for the activities they undertake. The self calibration learns from the way the person walks and effectively looks after the rest and you end up with specific setting for each individual.

1) What role do you feel 3D printing has (or can have/will have) in the prosthetics world? 2) What advice do you have for a college student who is interested in getting into industry for Biomedical Engineering?

Factories of future in Prosthetic and Orthotics in my view will be using 3D printing, additive manufacture for future integrated products and services. See link below to MovAid project. I think this technology already have started to change the industry and enabling access for developing countries. http://www.ispoint.org/news/ispo-participates-movaid-under-eu-horizon-2020

Also see UN WHO Gate program with the aim of eradication of disability with mobility as #1 challenge.

Do prostetic limbs need external power, or are you able to get them to run exclusively on the energy of the human body?

The ones we are supplying currently uses external power to control electronics, processors, sensors and actuators for damping and control of level of energy absorption to springs. The batteries in the Linx last for several days. There are a few products in the market which uses external power to drive an electric motor or tighten a spring to provide assistance and their batteries last hours. The future however, will be more devices which uses the external power to power the limb and assist with power when needed to replace the loss of muscles and power.

Do you see the prosthetic leg ever being integrated with medical monitoring devices like Neural Dust? https://www.inverse.com/article/19462-tiny-wireless-implants-neural-dust

Yes, already we are monitoring activities in prosthetic devices and we need to look at Neural Dust and learn more. I think once they are readily available for all amputees we can integrate them for better control, and closer integration with the user, the environment they are and the activity they are undertaking.

What have been the most important recent developments in the materials side of prosthesis manufacturing? Will i be able to replace my leg with a porcelain glock?

Carbon fiber Composite in 80s was used for its light weight and strength for structural parts. Today we use the composites to make efficient springs to fit in confined spaces of a replacement leg. Titanium powder for additive manufacturing is a current focus. The advance materials being developed for 3D printing use with different hardness will enable us to construct the whole limb.

My father's biggest issues with modern prosthetics are the bad performance on stairs and especially mountains, and the need to charge.

I assume you perform better than anything he was offered and tried, but how well are you adjusting to sudden changes in steepness? How do you differentiate between stairs and slopes? The article only mentiones sensors, what are you measuring for this purpose?

How long does a current charge last, how long for a full load and can one swap the battery in a reasonable time?

I'm studying engineering and your field is an area I'm interested in. Which industries would be a good platform to later join a company as yours? Would you value medical eng. experience at the cost of more traditional one?

Great that you are studying engineering. You can go to medical engineering from mechanical or electrical engineering.

Linx users are asked to charge it every day, but the users have suggested it has last sometimes for 5 days and more pending use. The batteries are swappable, as they are configured specially for Linx and have long charge and discharge life cycle. So should last long.

The ramp detect mode adjust to steepness and can provide greater resistance, as it combines with ankle that complies to ground it provides greater stability in steep inclines. Slopes are detected by sensors in the foot and stairs by the sensors in the knee. We measure acceleration, strain, bending moments, stroke, and many kinetic (under lying forces) and kinematics (the motions caused as the result of forces applied) parameters.

The devices are limited, however their performance is improving all the time and we need to match that with training how to use the limb and get best out of the limb

Was there a particular moment that made you decide that you wanted to go into developing prosthetic limbs? Or did it happen by accident?

Say hi to Aaron for me from his Eurovision hosting buddy.

It was not an accident. You see a need, and working in the NHS perhaps was catalyst. You know there are better solutions, and if you are working with a right team, the solution emerges.

Obviously Linx is for the Left leg. I hope you have made a Rinx version for the Right leg ?

good one.. Actually with Linx Right leg can talk to left leg on bi lateral amputees (later) More to come...

Realistically how affordable is this for the middle to low income people?

It is no more expensive than other microprocessor controlled prosthesis. In middle income societies is deemed affordable in my view and in low income countries at present is supplied on special cases. It is integrated limb so the cost of foot and ankle is also included. So pending on the reimbursement system of each country, its cost in a number of countries is covered by health insurance, worker compensations, or national health. In UK at present for NHS patients a case needs to be made justifying how the overall health cost will be reduced. In time with more evidence of reduced low back pain and reduced risk of falls or ulceration, and reduced risk of damage to anatomical joints, the case for affordability will be smaller cost of overall life time heath economics.

Going to study Mech Eng in September at the University of Bristol.

What do you look for in job applications? What are things I can do to maximise my chances of working for your company or in robotics in general?

Thank you in advance!

I wish you the best in doing your degree in Mech Eng. Great Choice and Great University. While you are doing your degree you will get a better idea if you want to work in a R&D environment (discovering a tendency to develop solutions or you are more likely to want to do research to discover, or manage projects or lead a team). So depending on the job, if the job is looking for a design engineer for R&D, then we look to see if the person is a R&D type of person. If we are looking for a test engineer, then certain systematic characteristics as well as core understanding of engineering is deemed valuable. The same for production or manufacturing. So to match the person's ability and their natural aptitude to the job is the key. The best way to find out for yourself is to do as much work experience as possible in a variety of engineering field, and you will then know.

I am an amputee. I've always been interested in volunteering with an engineering company to test new products, but I've never known if you all do that. Do prosthetic companies take volunteers to test products? How would I go about doing so?

Amputee test pilots are our life line. We have a number of them working for us and with us as volunteers. We always need more. Contact your local prosthetists and tell them that it is what you want to do and want to help to test and provide feedback on new ideas We are there

If your prosthetic was any smarter, could it write a book, and then could it read it to me?

Theoretically yes, as robotics are enabling us to do more with sensors and processors. Our focus is on applying technology to artificial limbs for people who have lost their leg and need their mobility back.