Project

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40 Add-on box for old stereo systems
Chutian Shao
Tong Zhao
Ziyang Liu
Jose Sanchez Vicarte design_document0.pdf
final_paper0.pdf
presentation0.pdf
proposal0.pdf
Members:
Tong Zhao (tzhao11)
Chutian Shao (cshao5)
Ziyang Liu (zliu63)

Problem:
Old stereo systems often lack modern features like equalizer and convenient way of control. For example, a user need to physically turn volume knob or press buttons on the audio equipment.

Solution:
A cheap add-on box that can be inserted into the signal path of existing stereo systems. It will be controlled wirelessly via Bluetooth using a smartphone app, and uses RCA for inputs and outputs, so it is compatible with most existing audio equipments. It will provide the following features:

- Volume control
- Select between multiple inputs (Multiplexer)
- Equalization (EQ)
- L/R channel balance
- Sleep timer / alarm: mute/unmute at user specified time

There are two approaches of doing the signal processing: one is using analog circuits. The other one is to use an ADC to convert the analog audio signal to digital and do all the processing digitally, and use a DAC to convert back to analog. If we go this way, we are able to add more DSP effects (reverb, etc.), even dynamically load/unload effects with the smartphone app. However, the additional ADC/DAC will decrease audio quality.

Since signal processing decreases audio quality, the device will have an audiophile/Hi-Fi mode that bypasses all processing except volume control to keep audio quality as close to input as possible.

The device will be powered by standard USB port.

Recovery-Monitoring Knee Brace

Dong Hyun Lee, Jong Yoon Lee, Dennis Ryu

Featured Project

Problem:

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.

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Solution:

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.

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Audience:

1) Average person with leg problems

2) Athletes with leg injuries

3) Elderly people with discomforts

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Equipment:

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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