• HAND
  • sketches
  • development process
    development process
  • models
  • material testing
    material testing
  • prototype v1
    prototype v1
  • mechanism design
    mechanism design
  • prototype v2
    prototype v2
  • final prototype
    final prototype
  • production & assembly
    production & assembly
What It Does

HAND is a hand surgery simulator that it used to teach young surgeons surgical procedures such as syndactyly release and z-plasty.

The Inspiration

HAND is a hand surgery simulator that it used to teach young surgeons surgical procedures such as syndactyly release and z-plasty. It covers the training of the process of planning, incising and suturing.

Before a surgeon is able to perform surgical procedures such as the syndactyly release and z-plasty, he/she would usually attend a course which teaches them the knowledge required for the surgery through a textbook. Then, he/she would be attached to a senior surgeon to observe the surgery for a few times, before performing it on an actual patient.

Through interview and research, we realized that due to the nature of surgeries such as syndactyly release and z-plasty, which have relatively small number of occurrence, it is not possible for all surgeons to get a chance to observe, much less practice the surgical procedures. Also, quoting Dr Alphonsus Chong, Head & Senior Consultant, National University Hospital - Department of Hand & Reconstructive Microsurgery, it is unacceptable for one to perform the surgical procedure for the first time on a real patient.

This project is a collaboration between NUS: Division of Industrial Design & NUH: Department of Hand & Reconstructive Microsurgery. The brief is to create a simulator to be used on 16 November 2013, during a training course to teach young surgeons Z-Plasty and Syndactyly Release. This is the first time that a course of this nature is conducted.

How It Works

HAND is a hand surgery simulator that it used to teach young surgeons surgical procedures such as syndactyly release and z-plasty.

HAND features key landmarks found on the human hand, like knuckles and joints, to be used in the planning stage of the surgical procedure. This prepares them to optimize skin use during the actual operation and minimize skin deficit, which in turn reduces the amount of grafting required. This would serve to reduce the recovery time of the patient.

Surgical gloves with a layer of transparent film dressing applied to simulate the layers and tension of human skin to the required level of realism. These materials are readily available in hospitals. This would not only reduce the cost of each training, but also allow younger surgeons to have more opportunities to practice unlike the conventional medical simulators for other surgeries found on the market which can be costly.

HAND also features a springing motion when the "skin" of a specific area is incised. This is similar to the situation where the skin tension of the patient's hand is released during the syndactyly release procedure.

Stages of Development

We went through the process of preliminary research, interview, observation, concept generation, prototyping, testing and evaluation, final refinement and prototyping, testing, design for manufacturing and finally production.

Preliminary Research:
Before meeting the surgeons for the first time, we did secondary research to understand about the surgical procedures involved in the brief and to understand specific jargon that is used in this context. This allows us we better prepare for effective communication during the first meeting with the surgeons so as to gathering accurate insights.

We interviewed a few surgeons to understand the problem with the current teaching method and understood that the current course material only consist of a textbook and one of the key insights was that the younger surgeons, who lacked actual experience, had difficulty visualizing the human hand and this would directly affect the planning stage of the operation, which was the most crucial part as it is important for incisions to be planned beforehand to reduce skin deficit.

We were given an opportunity to observe the actual surgical procedure inside the operating theatre and this serves to confirm several points that the surgeons had highlighted during the interview and also allowed us to have a actual visual understand of the whole process. This allows us to eliminate assumptions and uncertainties.

Concept Generation:
By putting all the insights and material we have gathered through our research process, we began generating concepts of possible simulator types. In this process, we produced several "quick and dirty" models to illustrate concept of operation for each of the types and this was done in preparation for the next meeting with the surgeons to obtain feedbacks and suggestions which eventually leads to the final chosen concept, which is a hand simulator consisting of an inner structure and an replaceable "skin" which will be the main working surface during the simulation.

After the final concept is confirmed, we designed the mechanisms and the components required via computer-aided design to first simulate and identify any possible problems faced. After confirming that the parts are ready for fabrication, prototyping was done through the use of 3D-printing and CNC. Concurrently, material testing was performed in order to find a suitable material to be used to simulate the human skin. The material was selected based on the ability to simulate the elasticity and the texture of the human skin as realistic as required. In the end, the use of a surgical latex glove with a layer of transparent dressing film applied was selected as it was able to prevent the "skin" from springing apart after the incision, which was similar to the human skin. The prototype was assembled with the skin mounted to be used for testing and evaluation.

Testing & Evaluation:
The prototype was presented to the collaborators and a training was simulated according to how the course would be conducted. The process was documented via video for insights gathering after the process. Minor adjustment was to be made to make the landmarks found on the human hand more visible (knuckles, joints, etc)

Final Refinement & Prototyping:
The model was modified via CAD to make the required adjustments and also to improve the ease of assembly. The refined prototype was then produced for final testing before production.

Other than the functional aspect of the simulator, we also considered the durability of the material used so that high maintenance can be avoided. We made use of the tools provided by the surgeons (scalpels, suture, etc) to simulate extreme uses in order to confirm that the simulator is long-lasting. The prototype is then presented to the surgeon for final testing and the process is recorded and presented in the video.

Design For Manufacturing:
After the design is confirmed, we proceeded on to optimizing the simulator for the selected production method, which was 3D-printing. By making component modular, we were able to increase the production rate and consistency of the parts. This also opens up the possibility of replacing individual components in the event that repair is required.

A total of 10 pieces were produced to be used for a course that was conducted on 16 November 2013. The simulators received good feedback and was to be used for future courses.

This project has not been commercialized. A total of 10 pieces were produced to be used for training courses conducted within National University Hospital (Singapore)


This project has not been entered in other competitions.