Because of the poor economic situation and lack of medical resources in the developing world, this device must cost less than $4 in quantities of 500, achieve minimal maintenance and considerable longevity. Specifically, this device must output a normal sinus rhythm waveform including the P wave, QRS complex and T wave at varying heart rates as well as a 1 mVpp sine wave in order to test the function and the frequency response of the ECG machine. The target heart rates for the device are 40, 70, 130, 190 bpm and the target sine frequencies are 1, 5, 10 and 50 Hz. The main goals of this project are to create a safe, reliable, low cost device which can simulate the normal sinus rhythm of the heart. Addition of the sine wave output and varying pulse rates would improve the product and are desired, but will be completed if time and resources permit. Through the development of this device, engineers will have a more effective way to identify problems with ECG machines and subsequently test repairs made to malfunctioning ECG machines.
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Step 1: Specifications
- Sine Waves
- 1 mVpp4 @ 1 Hz, 5Hz, 10Hz, 50Hz
- Normal Sinus Rhythm Waveform
- Include P wave, QRS complex, T Wave
- 40, 70, 130, 210 bpm5
- Mimic the impedance of the chest cavity at device outputs.
- Cost less than $4 in quantities of 500.
- Blink an LED that corresponds to the frequency or rate of device when it is on.
- Achieve minimal maintenance and considerable longevity.
- Maintain functionality for 10 years.
- Switch contacts
- No encapsulation will be used because of the complexity of the switch.
- Last for at least 1 year on 3 AA batteries, assuming a sporadic 20 hrs per year of usage.
- Measures less than 4" x 4" x 1" when stored.
- Three alligator clips on the test will clip to the positive (right arm), negative (left arm) and ground (left leg) leads of the ECG machine.
Step 2: Materials
1 Battery Pack
3 Alligator Clips
1 330K Ohm Resistor
3 560 Ohm Resistor
1 33 uF Capacitor
Small Phillips Screwdriver