MediKnit: Soft Medical Making for Personalized and Clinician-Designed Wearable Devices for Hand Edema
Current rapid prototyping in medical domains relies on rigid 3D-printed materials, lacking flexibility, customization, and clinician-led input. This paper introduces MediKnit, a novel approach for the fabrication of soft medical devices, addressing critical limitations in existing design processes for medical devices.
MediKnit provides a design tool empowering clinicians to personalize fabric-based devices for hand edema. This tool allows clinicians to adapt the design to individual patients’ demands, thereby enhancing the overall effectiveness of therapy. The MediKnit device created by this tool consists of a machine-knit glove with active compression, which is programmable through a custom PCB. This device facilitates the mobilization of edema. To illustrate the practical implementation of our approach, this paper presents case studies involving six patients experiencing hand edema. The results demonstrate the adaptability and feasibility of our process for developing soft medical devices, highlighting its potential to broaden accessibility, facilitate personalized solutions, and empower clinicians as active medical makers.
Publication:
MediKnit: Soft Medical Making for Personalized and Clinician-Designed Wearable Devices for Hand Edema
Heather Kim, Narjes Pourjafarian, Arhan Choudhury, Joan Stilling, Cindy Hsin-Liu Kao
Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies (IMWUT) 2024
PDF | DOI | Project Page
Project Credits:
Hybrid Body Lab at Cornell University, directed by Cindy Hsin-Liu Kao
Heather Kim (Lead Researcher), Narjes Pourjafarian, Arhan Choudhury, Joan Stilling, Cindy Hsin-Liu Kao
This project was funded by Cornell University Multi-Investigator Seed Grant 3223364
MediKnit system consists of a knitted substrate, 13 shape memory actuators, and hardware. (i) Substrate creates "channels" for actuators, (ii) accommodates swelling in the prominent direction, and (iii) covers hand corners. (b) The 13 actuators are designed based on lymphatic vessels distribution. (c) MediKnit device on participants with hand edema. Superimposed pictures show visible compression marks.
Left: Heat map of the actuated glove placed on a table. At a PWM of 80, SMA springs on the finger reached 31.6◦C and on the palm 30.2 - 31.6◦C. Right: Heat map of the actuated glove while worn on the hand. At a PWM of 127, finger temperatures hit 40.4°C and palm temperatures 37.8 - 39.8◦C, creating a comfortably warm sensation with pronounced pressure. While SMA springs are actuated sequentially, it takes time for recently activated SMAs to return to room temperature.
MediKnit design tool provides: (a) Visual guidance for thirteen hand measurements for customization; (b) Backend algorithm converts the measurements to 18 coordinate points; (c) and (d) A glove template is generated based on these coordinates, with options for therapists to adjust both the template and SMA channels; (e) The design tool then creates a machine-readable file.
Sequence diagram of MediKnit design tool.