Prostheses are artificial arms, legs or body parts that restore a reasonable degree of normal function of a limb or body part for amputees or people who have lost the normal use of a body part. Historically, prostheses have been available as beautifully designed imitations of arms, legs and other body parts. Unfortunately, these prostheses were inflexible and non-functional. In the twentieth century, materials such as modern plastics made it possible to design strong but lightweight prostheses that more closely matched missing body parts.
With advances in CAD/CAM technology and 3D printing, it has become possible to design a new breed of myoelectric prosthetic limbs. Myoelectricity uses electrical signals from the body to move the prosthetic device, thereby enabling the person to have simulated motion of a body part. Could this novel approach toward designing prostheses be considered disruptive?
What is disruptive technology? In ordinary terms, it means that a new way of doing things overturns or replaces established or traditional practice. The Harvard professor M. Christensen defines disruptive innovation as one that creates a new market, so that it eventually disrupts an existing market and value network. These are examples of disruptive technology:
- The introduction of the internet changed the traditional method of sending stamped mail. Although the traditional method still exists and it has not been completely displaced, emails provide a fast, efficient way to communicate.
- The personal computer displaced the typewriter almost completely.
- Introduction of the cell phone disrupted the telecommunications industry, because people all over the world can now communicate and exchange information effortlessly.
- Robotic surgery made it possible for skilled surgeons to perform less invasive surgeries, and to perform surgical procedures remotely.
- 3D printing has significantly invaded the traditional manufacturing industry.
- Cloud computing is rapidly replacing in-house networking, and it is making it easier for companies to collaborate and to operate efficiently even when their branches are located on different continents.
It is possible for new technology to be revolutionary, but not disruptive. These are examples of revolutionary, but not disruptive technology:
- Invention of the automobile was revolutionary but not disruptive, because it did not displace horse-drawn vehicles. It only became disruptive when the cost of automobiles became affordable for the ordinary working person.
- The introduction of electric cars could become disruptive only when the cost of purchasing and operating an electric car becomes cost effective for the ordinary working person.
The purpose of this article is to determine whether modern prosthetics technology could be considered as disruptive. In order to be disruptive, modern prosthetics technology should satisfy two conditions:
- It should replace traditional methods of providing artificial limbs and prostheses,
- It should disrupt the existing healthcare market for prostheses.
On the basis of this premise, we could ask the following questions:
- What difficulties should be overcome to make modern prostheses commercially viable?
- How rapidly are modern prostheses displacing traditional prostheses?
What Difficulties Should Be Overcome To Make Modern Prostheses Viable?
These difficulties and hurdles should be overcome to make modern prostheses commercially viable:
- A prosthetic device should be lightweight and strong. It should also be aesthetically pleasing so that it looks as much as possible as the missing body part. For this reason, there is ongoing research to find suitable construction materials such as aluminum alloys, plastics and carbon fiber composites.
- It will be difficult to mass produce prosthetic devices, because each device should be custom made and fitted to the patient. Furthermore, when prostheses are fitted to children, the devices require continual re-design and fitting as the children grow and their bodily dimensions change. For these reasons, prosthetic devices are costly. With 3D printing, manufacturing costs should decline.
- A patient fitted with prosthetic device needs rehabilitation in the form of therapy and training to effectively use the device. The amount of training may not be extensive if the prosthetic device is myoelectric. However, if the loss of limb is congenital, extensive therapy is required.
How Rapidly Are Modern Prostheses Displacing Traditional Prostheses?
Apart from providing functionality in a prosthetic device, a main focus of prosthetic research is to provide comfort for the patient. It is well known that amputees fitted with ambulatory prostheses often experience pain and degenerative joint diseases, and that they exert increased energy in order to ambulate.
It is unfortunate that advances in prosthetic technology usually occur in tandem with acts of war. Nevertheless, certain significant advances are noteworthy. The advances utilize microprocessor technology, pattern recognition, and advanced surgical techniques.
This brief list highlights advances in prosthetic technology:
- The iwalk BiOM has become a commercially available foot and ankle device that restores powered movements for patients.
- Significant improvement has been made by the Military Amputee Research to develop a powered knee prosthetic device. Microprocessor technology is being utilized to make it easier for amputees to push freely into a knee joint without excessive pain. This technology is also helping to reduce low-back pain for amputees fitted with prosthetic knee joints. The Ossur Power knee is now a commercially available prosthetic device.
- Osseo-integration is emerging as a surgical technique for direct skeletal attachment of prostheses. The technique is in its infancy and awaits FDA approval. Its success will eliminate problems such as sweating, infections, fracture, loosening of implants, and socket pain.
- Targeted muscle reinnervation (TMR) is an area of research that seeks to make myoelectric prostheses such as shoulder disarticulations functional. The technology uses advanced pattern recognition to decipher surface electrode data from the patient, and to associate the data with prosthesis control and response. For example, electrode signals generated when a patient closes a hand are programmed into the myoelectric prosthesis to generate the desired response.
Conclusions
Modern prosthetic devices should satisfy many conditions to become commercially available. These include (a) functionality, (b) comfort for the patient, (c) FDA approval, (d) customization, and (e) cost effectiveness.
For these reasons, it is unlikely that modern prostheses will completely replace traditional prostheses in the near future. At this time, modern prosthetics technology is revolutionary, but not disruptive.
– IndiaCADworks
