Design Document

Video Lecture

Video, Slides


The design document communicates the complete and detailed design of your project. It is substantially more detailed than the proposal and prepares you for the assembly phase of the semester. A quality design document is the key to a successful project. Use the following format.

  1. Introduction

    • Objective: One to two paragraphs detailing the problem statement and proposed solution.
    • Background: One to two paragraphs explaining the context of the problem to be solved by your project, including any relevant references to justify the existence and/or importance of the problem (i.e., the need or want for a solution).
    • High-level requirements list: A list of at most three quantitative characteristics that this project must exhibit in order to solve the problem. Each high-level requirement must be stated in complete sentences and displayed as a bulleted list.
  2. Design
    • Block Diagram: A general block diagram of the design of your solution. Each block should be as modular as possible. In other words, they can be implemented independently and re-assembled later. The block diagram should be accompanied by a brief (1 paragraph) description of the high level design justifying that the design will satisfy the high-level requirements.
    • Physical Design (if applicable): A physical diagram of the project indicating things such as mechanical dimensions or placement of sensors and actuators. The physical diagram should also be accompanied by a brief one paragraph description.
    • Block Design: A detailed design for every block in the block diagram, including software and mechanical design. Each block design should include the following.
      1. Functional Overview: A highly detailed and quantitative block description. Each description must include a statement indicating how the block contributes to the overall design dictated by the high-level requirements. Any and all design decisions must be clearly justified. Any interfaces with other blocks must be defined clearly and quantitatively.
      2. Requirements and Verifications: Requirements and verifications for each block must be included. Please see the R&V page for guidance on writing requirements and verification procedures.
      3. Supporting Material: Include any relevent supporting figures and data in order to clearly illustrate and justify the design. Typically a well justified block design will include some or all of the following items:
        • Circuit Schematics
        • Simulations
        • Calculations
        • Measurements
        • Flow charts (often for software)
        • Mechanical diagrams (e.g. CAD drawings, only necessary for mechanical components)
    • Tolerance Analysis: Through discussions with your TA, identify a critical requirement to explore in great detail. Your analysis of that component will prove that your implementation will meet that requirement. See the Tolerance Analysis guide for further guidance.
  3. Cost and Schedule
    1. Cost Analysis: Include a cost analysis of the project by following the outline below. Include a list of any non-standard parts, lab equipment, shop services, etc., which will be needed with an estimated cost for each.
      • LABOR: (For each partner in the project)
        Assume a reasonable salary ($/hour) x 2.5 x hours to complete = TOTAL. Then total labor for all partners. It's a good idea to do some research into what a graduate from ECE at Illinois might typically make.
      • PARTS:
        Include a table listing all parts (description, manufacturer, part #, quantity and cost) and quoted machine shop labor hours that will be needed to complete the project.
    2. Schedule: Include a time-table showing when each step in the expected sequence of design and construction work will be completed (general, by week), and how the tasks will be shared between the team members. (i.e. Select architecture, Design this, Design that, Buy parts, Assemble this, Assemble that, Prepare mock-up, Integrate prototype, Refine prototype, Test integrated system).
  4. Discussion of Ethics and Safety:
    1. Expand upon the ethical and safety issues raised in your proposal to ensure they are comprehensive. Add any ethical and safety concerns that arose since your proposal.
    2. Document procedures to mitigate the safety concerns of your project. For example, include a lab safety document for batteries, human/animal interfaces, aerial devices, high-power, chemicals, etc. Justify that your design decisions sufficiently protect both users and developers from unsafe conditions caused by your project.
      Projects dealing with flying vehicles, high voltage, or other high risk factors, will be required to produce a Safety Manual and demonstrate compliance with the safety manual at the time of demo.
  5. Citations: Any material obtained from websites, books, journal articles, or other sources not originally generated by the project team must be appropriately attributed with properly cited sources in a standardized style such as IEEE, ACM, APA, or MLA.


The DD Grading Rubric is available for your viewing pleasure. An example is available available to illustrate the expectations for a high quality Design Document: Sample DD.

Submission and Deadlines

Your design review document should be uploaded to PACE in PDF format by the deadline shown on the course calendar (typically midnight the Friday before Design Review). If you have uploaded a mock DR document to PACE, please make sure that it has been removed before DR.

Recovery-Monitoring Knee Brace

Dong Hyun Lee, Jong Yoon Lee, Dennis Ryu

Featured Project


Thanks to modern technology, it is easy to encounter a wide variety of wearable fitness devices such as Fitbit and Apple Watch in the market. Such devices are designed for average consumers who wish to track their lifestyle by counting steps or measuring heartbeats. However, it is rare to find a product for the actual patients who require both the real-time monitoring of a wearable device and the hard protection of a brace.

Personally, one of our teammates ruptured his front knee ACL and received reconstruction surgery a few years ago. After ACL surgery, it is common to wear a knee brace for about two to three months for protection from outside impacts, fast recovery, and restriction of movement. For a patient who is situated in rehabilitation after surgery, knee protection is an imperative recovery stage, but is often overlooked. One cannot deny that such a brace is also cumbersome to put on in the first place.



Our group aims to make a wearable device for people who require a knee brace by adding a health monitoring system onto an existing knee brace. The fundamental purpose is to protect the knee, but by adding a monitoring system we want to provide data and a platform for both doctor and patients so they can easily check the current status/progress of the injury.



1) Average person with leg problems

2) Athletes with leg injuries

3) Elderly people with discomforts



Temperature sensors : perhaps in the form of electrodes, they will be used to measure the temperature of the swelling of the knee, which will indicate if recovery is going smoothly.

Pressure sensors : they will be calibrated such that a certain threshold of force must be applied by the brace to the leg. A snug fit is required for the brace to fulfill its job.

EMG circuit : we plan on constructing an EMG circuit based on op-amps, resistors, and capacitors. This will be the circuit that is intended for doctors, as it will detect muscle movement.

Development board: our main board will transmit the data from each of the sensors to a mobile interface via. Bluetooth. The user will be notified when the pressure sensors are not tight enough. For our purposes, the battery on the development will suffice, and we will not need additional dry cells.

The data will be transmitted to a mobile system, where it would also remind the user to wear the brace if taken off. To make sure the brace has a secure enough fit, pressure sensors will be calibrated to determine accordingly. We want to emphasize the hardware circuits that will be supplemented onto the leg brace.

We want to emphasize on the hardware circuit portion this brace contains. We have tested the temperature and pressure resistors on a breadboard by soldering them to resistors, and confirmed they work as intended by checking with a multimeter.

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