Medical Instrumentation

Design Project > Information

Design Project Information

EE-436 is a capstone design course, so be prepared to design medical instrumentation systems!

The purpose of the laboratory is to provide hands-on experience with the topics and systems described in the course.  These will be primarily electronic systems for the measurement of human physiological parameters.  The laboratory problems will involve some degree of research and development on the part of each student group.  This will involve both the design, prototyping and testing of electronic circuits, as well as the development of measurement procedures for characterizing the circuits and using the systems in practice.

Lab Groups:
Each group will consist of either 2 or 3 students. Each group must submit ONE set of design documentation for the capstone design project. Each student in the group receives the same laboratory design project grade; thus, you should choose a group that you can work well in!  Students MAY NOT switch between lab groups throughout the quarter. 

Sections: AA Tuesday, 11:30am - 2:20pm room 137 EEB
AB Wednesday, 10:30am - 1:20pm room 137 EEB
First Lab Meeting: AA Tuesday, April 8, 2013 room 137 EEB
AB Wednesday, April 9, 2013 room 137 EEB

Structure of the Capstone Design Project:
Four options of starter projects (denoted Lab 1 and Lab 2) are provided which are intended to accelerate each group's progress toward the capstone design project. These are purely optional, none of these contribute to the final grade, but they can provide helpful starting points for some of the more basic measurement system designs.

Option A: Electrophysiology
Lab 1A: Design of an ECG Preamplifier
Lab 2A: Design of an ECG Recording System

Option B: Circulation
Lab 1B: Design of an Optical Heart Rate Monitor
Lab 2B: Design of a Pulse Oximeter

Option C: Respiration
Lab 1C: Design of a Differential Pressure Pneumotachometer
Lab 2C: Design of a Respiratory Capnometer

Option D: Metabolism
Lab 1D: Design of a Limb Motion Accelerometer
Lab 2D: Design of a Muscle Dynamics Tonometer

Laboratories 1 and 2 are linked pairs for each of the four starter project options. Laboratory 1 starts the development of a core design, and Laboratory 2 takes that design a step farther in sophistication and complexity.

The capstone design project occupies the majority of the quarter. Laboratories 1 and 2 are intended to provide a core design upon which the capstone design project can be based. It is not essential to use the designs of Lab 1 or Lab 2 within the capstone project, but the effort spent on them could save some development time for the capstone project. The capstone design projects are proposed by the student groups, and some library and web research will be required to properly specify the design goals and performance criteria. Some of these aspects will be undertaken as homework problems.

While the subject matter of this class is medical instrumentation, the class itself DOES NOT provide any training or certification in the practice of medicine!  Students should NOT assume that they are qualified to perform any medical or clinical procedures by being in the class or having taken it.  These skills are taught in the Department of Medicine, NOT in the College of Engineering.  Similarly, students are expressly forbidden to perform any clinical practices as part of the laboratory.  These would include, for example, taking blood or tissue samples from fellow students, placing electrodes on their own or a fellow student’s body, or measuring any fellow student’s physiological parameters without their express consent.  When in doubt, consult the teaching assistant or the instructor! 

Design Documentation:
The capstone design project requires a suitable set of professional quality design documents to be submitted.  The file Electronic Design Documentation describes what should be included in a documentation package, and gives some general guidelines for putting one together.  An example of a complete design documentation package is the Leach 120 Watt Stereo Power Amplifier.  This is only an example of what a set of design documents should look like in their level of detail and organization.  The specifics of what is required for each group's design project will vary, but it is expected that the final documentation package will provide a complete, clear, and concise description of the developed measurement system.

Parts for Prototyping:
The development of the capstone design project will require that some components be purchased from either the EE Stores, or from another electronic parts supplier.  A solderless breadboard (aka superstrip) is generally a good route for prototyping the circuits used in the laboratory.  These can also be purchased from the EE Stores. Data sheets for common parts and transducers can be found in the Laboratory > Parts page, along with some guidance on selecting and purchasing them. Some of the more specialized sensors used in the starter projects can be obtained from the instructor. Ask before buying! In all cases, be aware of ordering and lead times on specialized components.  

LabVIEW Data Acquisition:
Some of the design projects may involve the development of a LabVIEW data acquisition interface and subsequent signal processing. Here is a Quick Tutorial on LabVIEW Data Acquisition

Tektronix AFG3021 Arbitrary / Function Generators:
The Tektronix AFG3021 arbitrary / function generators (single channel, 250 MS/s, 25 MHz) can be used to produce a simulated ECG signal for testing biopotential amplifiers. Here are 3 ECG waveforms (.tfw files) that can be played back on the this instrument:

ECG signal at 30 bpm (30 beats per minute, 0.5 Hz)

ECG signal at 60 bpm (60 beats per minute, 1.0 Hz)

ECG signal at 180 bpm (180 beats per minute, 3.0 Hz)

To load any of these into the Tektronix AFG3021 arbitrary / function generator, first copy them over to a USB flash drive, and then use the following steps: 

  1. Turn on the function generator and attach the flash drive to the USB port in the front of the instrument. 
  2. Press Arb to select the arbitrary waveform menu
  3. Press USB in the memory menu
  4. Select the proper file from the USB memory; navigate the folders as necessary using the Change Directory button
  5. Use the WriteTo option in the Edit menu to copy the .tfw file to the function generator
  6. Play the file using the normal front panel controls

Agilent 33120A 15 MHz Function / Arbitrary Waveform Generators:
The Agilent 33120A 15 MHz function / arbitrary waveform generators may also be used to produce simulated ECG signals. These generators have a built-in cardiac waveform which can be used. To obtain the cardiac waveform, use the following steps:

  1. Turn on the function generator
  2. Press the Arb button (a sinc waveform is the default arbitrary waveform)
  3. Press Shift, Arb List, and the < or > keys to select Cardiac, and then press Enter
  4. To produce a HR of 60 bpm (1 Hz), press Freq, Enter Number, 1, and press Hz
  5. The minimum amplitude of this waveform is 3.3 mVrms or 31.73 Vpp into 50 Ohms. Note that the default for the 33120A is a 50 Ohm source impedance, so if the load is a high impedance, then the delivered voltage will be twice the displayed value. Because these minimum signal amplitudes are greater than most real biopotentials, an attenuator will usually be needed to create an appropriate low-level signal for testing any biopotential amplifier.