Prosthetic limbs can play an important role in the rehabilitation process for people who have lost an arm, leg, or other extremities as a result of amputation. They not only help improve mobility, but they also empower amputees to stay independent and navigate their day-to-day lives easier.
As such, prostheses are generally custom fit to the exact shape and size of a patient’s limb to ensure maximum comfort and functionality. Fortunately, advancements in medical technology, like 3D scanning, have made the prostheses fitting process easier and more accurate.
With 3D scanning, we have the potential to create three-dimensional visualization of any product without even a millimeter out of shape. This means that patients can now have their prostheses customized using high-resolution images that provide more detailed information than ever before. This not only helps make sure that the limb fits properly—which makes it easier to use and improves comfort—but also allows for adjustments to be made as often as necessary throughout the life of a prosthetic limb.
Keep reading to learn more about 3D scanning and how it can help with the prosthesis fitting process.
What Is 3D Scanning?
3D scanning, also known as photogrammetry, is now becoming increasingly popular in the medical field for its use in prosthesis fitting. Instead of having a technician custom-tailor a prosthetic over a week, 3D scanning can get all the complex work done in just 15 minutes, and the resulting scan can be 3D printed in almost no time. Moreover, 3D-printed prosthetic limbs are more affordable and can even be customized to the most minute details, including the patient’s skin tone.
How Can 3D Scanning Help with Prosthesis Fitting?
Before the early 1990s, plaster of Paris was used to capture the exact shape and size of the limb to create a prosthesis. This process is often referred to as shape capture. The plaster of Paris was poured into a mold, then modified with various sculpting tools to achieve the final shape before wet lamination or thermoforming. Later, as technology evolved, digital fabrication transformed how prosthesis fitting was done, and now shape capture happens with the help of computers.
CNC carving of foam, plaster molds, or 3D printing are all examples of digital fabrication. 3D scanning is now becoming one of the most preferred ways of getting fitted for a new prosthesis. This is because it is a more accurate way of measuring and creating a custom socket for your prosthetic limb, ensuring better fit and comfort.
The quality of the measurements from 3D scanning provides more information about where the parts should be placed in relation to each other, helping them form a tight fit around your limb. This will help you minimize the pain and discomfort that would otherwise be caused by poorly fitting prosthetic components or uneven pressure points on the body.
3D scanners can also be used to make temporary or permanent prostheses that have been fitted using 3D scan data as opposed to traditional methods like physical measurement or handcrafting. This also allows for greater customization since prostheses can be made in all sizes without having to compromise on style or comfort.
Additionally, since 3D scanners can capture details, such as pores on the skin, and at high resolutions, they can help create more realistic models than those created with photographs alone. These devices have no limitations when it comes to materials and can work with virtually any material.
The 3D Scanning Process for Upper Extremities
3D scanning is a process that uses a specialized device to take digital images of an object, person, or space. The scanner captures data points on the surface of the object and then uses a computer program to combine these data points into a 3-dimensional image. When this principle is applied to prosthesis fitting and design, the results we get are more accurate and ensure better fit and comfort for the patient.
When it comes to prosthesis fitting for upper limbs, the process begins with identifying the patient’s needs through an initial interview about their lifestyle, hobbies, and activities, as well as any challenges they face with their current prosthesis fit.
After this assessment, there will be follow-up appointments to take measurements.
Step 1: The technician will pay attention to the shape of the residual limb before scanning.
Step 2: They will make sure that the fingers are spread evenly, and the wrist is properly positioned. If the fingers are placed too wide, or the wrist is titled at an unnatural angle, it can negatively affect the 3D scanning image quality.
Step 3: If it is a partial hand, wrist, or above wrist amputation or wrist disarticulation, they will use a blue tack to mark the side with the palm before the scan.
Step 4: Then, they will take a photo of the residual limb with blue tack and send it together with the STL file.
Step 5: The prosthetic experts at Fit Prosthetics will get a clear visualization of the blue tack mark on the cast to represent the palm. Also, it’s best to scan the forearm at least 70 mm from the wrist position. This will give us more data for the trail fabrication.
Step 6: If the residual limb has no obvious wrist position, the technician will use a blue tack to mark three dots on the wrist area to represent the palm and wrist position.
Step 7: If the residual limb has sensitive spots, place blue tack on the center of the sensitive spot and mark the size of the sensitive site on the photo when we print out the 3D cast. We can compare the cast against the picture; then, we can locate the accurate position and estimate the actual size of the sensitive spot.
The 3D Scanning Process for Lower Extremities
The 3D scanning process for the lower extremities is similar to the one for the upper extremities. The process begins with the patient having their foot or ankle flexed, which helps create a more accurate representation of the limb as it would be in everyday use. Once this step has been completed, a scanner will be placed over the patient’s limb and rotated around it at different angles. This allows for both topographical data and surface measurements to be collected without any additional invasive techniques being used on the patient’s body.
Once all of this information has been collected by your 3D scanner, you’ll need to process it so that you can create a prosthesis model based on these measurements.
The Benefits of Using 3D Scanning for Prosthesis Fitting
Helps Create a Pressure Map
3D scanning can create artificial limbs more efficiently. When you stand upright, there are certain pressure points in your feet. Insoles are shaped based on these points. 3D scanning makes it easy to extract the patient’s pressure map.
More Accurate
With 3D scanning, casting accuracy is enhanced. This technology doesn’t miss out even on a millimeter. As a result of 3D scanning’s accuracy, medical professionals can eliminate errors while taking measurements and creating pressure maps. They can also speed up the prosthesis designing process without compromising on quality
Improved Comfort
A 3D-printed prosthetic limb will be more stable and durable, which means you can wear it longer without pain or discomfort. It will also be easier on your skin since the prosthetic device won’t run or rub against your skin as much. The result is that you’ll feel better in general while wearing your artificial limb if it’s fitted properly and doesn’t interfere with your daily activities.
Cost-Effective
Digitizing the fitting process can also save time and reduce overall costs. For example, when using a physical mold, you must also take into consideration the time and money involved in shipping the mold to labs and manufacturing facilities. On the other hand, 3D scanning allows medical professionals to treat many patients at once with greater precision, speeding up the process and helping you save money and time by minimizing the need for corrections.
3D scanning is a new and exciting technology that is helping to transform the field of prosthesis fitting. With this technique, patients can get a more accurate fit in less time with fewer visits than traditional methods. Contact the Fit Prosthetics team in Salt Lake City, Utah, to learn more about 3D scanning and prosthesis fitting.
