In 2023, ZOZOFIT's scanning technology was utilized in a study based on how our technology can help track and measure limbs affected by lymphedema. The study was conducted by Ryo Karakawa (Deputy Chief of Plastic Surgery, Ariake Hospital) and results of this research were presented by Karakawa et al. at the Annual meeting of the American Society of Reconstructive Microsurgery (January 12-16, 2024).

Authors: Ryo Karakawa, Tomoyuki Yano.

Overview:

This study was conducted through a collaborative research effort between the Cancer Institute Hospital of the Japanese Foundation for Cancer Research and ZOZO Inc. 

Objective:

Looking at the feasibility and utility evaluation of limb circumference measurement method using a measurement suit (ZOZOSUIT) and smartphone app (ZOZOFIT) in Lymphedema.

Key Points of Presentation:

• The use of the ZOZOSUIT, a 3D body measurement suit paired with a lymphedema-specific app for validation to assess the limb circumference measurement as an evaluation system of lymphedema 
• Limb circumference measurement using this device is highly accurate and offers a groundbreaking method for quick and easy measurements compared to traditional manual measurements
• The application of this technology is expected to contribute to lymphedema evaluation in a non-invasive and convenient way, without the need of a professional examiner 

Summary of Presentation:

• The Department of Plastic Surgery at the Cancer Institute Hospital of the Japanese Foundation for Cancer Research, Ariake Hospital (located in Koto-ku, Tokyo, Director: Takeshi Sano), led by Ryo Karakawa and Tomoyuki Yano, collaborated with ZOZO Inc. (located in Chiba City, President and CEO: Kotaro Sawada) to investigate the feasibility of limb circumference measurements using the ZOZOSUIT paired with the ZOZOFIT smartphone app to assess lymphedema in patients. The research findings suggest the potential usefulness of limb circumference measurements using this device as an evaluation tool for lymphedema. The results of this study were presented by Arigawa at the Annual Meeting of the American Society of Reconstructive Microsurgery in January 2024
• Lymphedema is estimated to affect over 150,000 people in Japan. It requires early detection and appropriate intervention to prevent worsening. However, there is a shortage of facilities capable of diagnosing lymphedema relative to the number of patients, leading to insufficient intervention for early or mild cases of lymphedema 
• The method using the ZOZOSUT suggests its potential usefulness as an evaluation system for lymphedema due to its ability to provide quick, easy, and accurate measurements. The application of this technology is expected to lead the development of a novel diagnostic tool that enables the non-invasive and repeated assessment of lymphedema treatment effects, early detection, and early intervention at home without the need of a medical professional 

Lymphedema is a condition characterized by swelling in the limbs due to lymphatic congestion. In Japan, cases of lymphedema are increasing with an estimated population of 150,000, particularly those following breast cancer and gynecological cancer surgeries. 

As the condition progresses, the volume and weight of the affected limb increase, leading to recurrent infections and reduced quality of life. Lymphedema is a chronic progressive disease for which there is currently no universally effective curative treatment. Therefore, a combination of conservative therapies such as compression garments and surgical interventions is necessary to prevent progression. 

Early detection, early intervention, and appropriate treatment, are crucial to prevent the worsening of the condition. However, since there is a shortage of facilities capable of diagnosing lymphedema, it is difficult to diagnose and assist those with early or mild cases of lymphedema. 

Given these circumstances and the need to prevent the worsening of lymphedema in patients and streamline lymphedema management, there has been a demand for the development of a simple yet accurate lymphedema evaluation system. 

In this study, the research team collaborated with ZOZO Inc. to investigate the feasibility of using it’s 3D body measurement suit, ZOZOSUIT, along with its dedicated smartphone app, ZOZOFIT, for lymphedema verification, to measure the limb circumference of patients with secondary lymphedema after cancer surgery. Participants wore the ZOZOSUIT and followed the instructions of the app, positioned 5 feet away, rotating 360 degrees and capturing 12 photos. The app automatically generates a 3D model of the body surface from these 12 photos, from which circumference measurements of important points for lymphedema treatment were extracted. 

This study conducted accuracy verification of repeated measurements using this system, as well as comparisons of circumference measurements with those obtained by conventional manual measurements performed by lymphedema treatment practitioners. The average error for all measurement points in repeated measurements was less than 10mm (1cm), and the average absolute error compared to conventional measurement methods was generally less than 20mm (2cm). Furthermore, the measurement time using this system was significantly shorter compared to manual measurements (1 minute 26 seconds vs. 3 minutes 50 seconds).

Based on the results of this study, it is expected that the application of this technology will lead to the development of a novel diagnostic tool that allows for a non-invasive, at-home assessment of lymphedema treatment effects, early detection, and early intervention without the need for an examiner. Furthermore, the high-precision data accumulation using the ZOZOSUIT may contribute to building evidence for unresolved issues in lymphedema treatment. While there are still challenges to practical implementation, the development of a lymphedema evaluation system using this technology could benefit patients by detecting it before it progresses to severe stages. This could also enable remote diagnosis, also benefiting healthcare workers by potentially reducing the need for extensive surgical interventions. 

Research Team:

Cancer Institute Hospital, Japanese Foundation for Cancer Research Department of Plastic Surgery: Tomoyuki Yano (Chief), Hidehiko Yoshimatsu (Deputy Chief). Lymph Care Room: Maiko Ogasawara (Therapist), Kuniko Utsugi (Chief). Kawabata Clinic. ZOZO Inc.

Glossary:

ISL Classification Stages I to IIb: Classification by the International Society of Lymphology (ISL).

• Stage 0: Impaired lymph transport with no apparent swelling, representing latent or asymptomatic pathology.
• Stage I: Relatively high protein content tissue fluid accumulation, still in the early stages and resolves with limb elevation. Indentation marks may be present.
• Stage IIa: Elevation of limbs alone no longer significantly reduces tissue swelling, and indentation marks become clearer.
• Stage IIb: Fibrosis of tissues is observed, and indentation marks disappear.
• Stage III: In addition to lymphedema without indentation marks, skin changes such as acanthosis and fat deposition become apparent.