Amputees with Phantom Limb Pain Helped by Augmented Reality
Published : 2016-12-02 - Updated : 2018-04-30
Author : Chalmers University of Technology - Contact: chalmers.se/en/Pages/default.aspx
Synopsis* : Method of treating phantom limb pain using machine learning and augmented reality.
Dr Max Ortiz Catalan at Chalmers University of Technology has developed a novel method of treating phantom limb pain using machine learning and augmented reality. This approach has been tested on over a dozen of amputees with chronic phantom limb pain who found no relief by other clinically available methods before. The new treatment reduced their pain by approximately 50 per cent, reports a clinical study published in The Lancet.
Phantom limb pain (PLP) refers to ongoing painful sensations that seem to be coming from the part of the limb that is no longer there. A phantom limb is the sensation that an amputated or missing limb (even an organ, like the appendix) is still attached to the body and is moving appropriately with other body parts. Approximately 60 to 80% of individuals with an amputation experience phantom sensations in their amputated limb, and the majority of the sensations are painful. The pains are often described as a burning or similarly strange sensation for people who are missing limbs. Other induced sensations include warmth, cold, itching, squeezing, tightness, and tingling.
People who lose an arm or leg often experience phantom limb pain, as if the missing limb was still there. Phantom limb pain can become a serious chronic condition that significantly reduces the patients' quality of life. It is still unclear why phantom limb pain and other phantom sensations occur.
Several medical and non-medical treatments have been proposed to alleviate phantom limb pain. Examples include mirror therapy, various types of medications, acupuncture, and implantable nerve stimulators. However, in many cases nothing helps. This was the situation for the 14 arm amputees who took part in the first clinical trial of a new treatment, invented by Chalmers researcher Max Ortiz Catalan, and further developed with his multidisciplinary team in the past years.
"We selected the most difficult cases from several clinics," Dr Ortiz Catalan says. "We wanted to focus on patients with chronic phantom limb pain who had not responded to any treatments. Four of the patients were constantly medicated, and the others were not receiving any treatment at all because nothing they tried had helped them. They had been experiencing phantom limb pain for an average of 10 years."
The patients were treated with the new method for 12 sessions. At the last session the intensity, frequency, and quality of pain had decreased by approximately 50 per cent. The intrusion of pain in sleep and activities of the daily living was also reduced by half. In addition, two of the four patients who were on analgesics were able to reduce their doses by 81 per cent and 33 per cent.
"The results are very encouraging, especially considering that these patients had tried up to four different treatment methods in the past with no satisfactory results," Ortiz Catalan says. "In our study, we also saw that the pain continuously decreased all the way through to the last treatment. The fact that the pain reduction did not plateau suggests that further improvement could be achieved with more sessions."
Ortiz Catalan calls the new method "phantom motor execution". It consist of using muscle signals from the amputated limb to control augmented and virtual environments. Electric signals in the muscles are picked up by electrodes on the skin. Artificial intelligence algorithms translate the signals into movements of a virtual arm in real-time. The patients see themselves on a screen with the virtual arm in the place of the missing arm, and they can control it as they would control their biological arm.
Thus, the perceived phantom arm is brought to life by a virtual representation that the patient can see and control. This allows the patient to reactivate areas of the brain that were used to move the arm before it was amputated, which might be the reason that the phantom limb pain decrease. No other existing treatment for phantom limb pain generates such a reactivation of these areas of the brain with certainty. The research led by Ortiz Catalan not only creates new opportunities for clinical treatment, but it also contributes to our understanding of what happens in the brain when phantom pain occurs.
The clinical trial was conducted in collaboration with Sahlgrenska University Hospital in Gothenburg, Örebro University Hospital in Örebro, Bräcke Diakoni Rehabcenter Sfären in Stockholm, all in Sweden, and the University Rehabilitation Institute in Ljubljana, Slovenia.
"Our joint project was incredibly rewarding, and we now intend to go further with a larger controlled clinical trial," Ortiz Catalan says. "The control group will be treated with one of the current treatment methods for phantom limb pain. This time we will also include leg amputees. More than 30 patients from several different countries will participate, and we will offer more treatment sessions to see if we can make the pain go away completely."
The technology for phantom motor execution is available in two modalities - an open source research platform, and a clinically friendly version in the process of being commercialised by the Gothenburg-based company Integrum. The researchers believe that this technology could also be used for other patient groups who need to rehabilitate their movement capability, for example after a stroke, nerve damage or hand injury.
Amputees with Phantom Limb Pain Helped by Augmented Reality | Chalmers University of Technology (chalmers.se/en/Pages/default.aspx). Disabled World makes no warranties or representations in connection therewith. Content may have been edited for style, clarity or length.
You're reading Disabled World. Be sure to check out our homepage for further informative disability news, reviews, disability sports events, exclusive stories and how-tos. You can also find us on Twitter, Facebook, and LinkedIn.
Related Electronics/Software Documents
- 1: Brain Computer Interface Allows Locked-In People to Communicate : Brain computer interface that deciphers thoughts of people unable to communicate could revolutionize lives of those with completely locked-in syndrome.
- 2: Hot Virtual Keyboard for Persons with Disabilities : Hot Virtual Keyboard for persons with disability speeds up screen typing by replacing Windows built-in On-Screen Keyboard.
- 3: Acapela TTS Voices for NVDA Screen Reader : Acapela TTS voices for NVDA enables blind and vision impaired people to use high quality and high performing voices with NVDA screen reader.
- 4: Launch of Web Portal on Accessible Workplace Technology : U.S. Department of Labor Office of Disability Employment Policy announces launch of PEATworks.org a comprehensive Web portal spearheaded by ODEPs Partnership on Employment and Accessible Technology.
- 5: Secure 3D QR Codes with No Internet Required : Article examines how QR codes can be a means to display 3D images and secure visual communication.
*Disclaimer: Disabled World provides general information only. Materials presented are in no way meant to be a substitute for professional medical care by a qualified practitioner, nor should they be construed as such. Any 3rd party offering or advertising on disabled-world.com does not constitute endorsement by Disabled World. View our Advertising Policy for further information. Please report outdated or inaccurate information to us.
Journal: Disabled World. Language: English (U.S.). Author: Chalmers University of Technology. Electronic Publication Date: 2016-12-02 - Revised: 2018-04-30. Title: Amputees with Phantom Limb Pain Helped by Augmented Reality, Source: <a href=https://www.disabled-world.com/assistivedevices/computer/plp-ar.php>Amputees with Phantom Limb Pain Helped by Augmented Reality</a>. Retrieved 2021-04-18, from https://www.disabled-world.com/assistivedevices/computer/plp-ar.php - Reference: DW#160-12531.