Week 8- Friday Feb 5th, 10-12 (Nazareth Visit)
Questions for Sara/Topics to Discuss
- Is the group planning to present Sara with the 6DOF sensor idea and get her input?
-Also, You can mention to her that with the 6 DOF sensor, it becomes very accurate. -Might be worth printing out the datasheet for it to show her?
- What kind of "Extreme" motion should we test? Do you have a specific kind of test process for a patient?
- If we use the off center attachment method, can we make it a uniform location for all patients? Or will it be unique for each person?
- With the triangle method of attachment, can we treat it as a rigid body?
- What is zero for most people?
- Discuss Amplifiers/Filters (as requested by Sara)
-We most likely wont need amplifying or much filtering, if so easy to implement and test with components in lab.
- Clarify triangular sensor arrangement
-Also, she mentioned the triangle system, how many regions is most likely to be looked at? i.e. upper lumbar/lower lumbar would require (2) 6 DOF sensors (I need to know this when looking at power consumption)
- Rank customer needs again (bring copy of needs)
- Can we use your VICON system or P10007's spine fixture to test our sensors?
- Do you know anything else about Dr. Heiderscheit's system? IDEEA?
-The single 6DOF sensor is around $125.00, plus whatever wires and the microcontroller around $150.00-$400.00, Is Sara fine with that amount of money going home with the patient?
- Sara has a new EMG system with wireless recorders-
made by a italian company named Aurion.
- 50-500 HZ
- Obtained through a US vendor named Narokian? US Vendor now has their own EMG system
- Regarding motion tracking there are 2 separate
schools of thought.
- School 1 says should do full body tracking
- School 2 says should focus on specific parts
- Sara is mostly interested in lower back tracking- but maybe middle. Her VICON system requires 3 markers for each lumbar segment in order to get 6 DOF, but we would only need 1 6 DOF sensor per lumbar segment.
- We definitely need to mount our sensors off-center due to spinal structure and skin motion. We will need to adjust our calculations slightly to counter this.
- 5-10 degrees = maximum rotation that will be seen in
a human's spine
- We can set our computer program to accept "inputs" for each sensor- then Sara can manually type in the offset values for each sensor. Due to the muscle structure of humans' backs it is impossible to have 1 fixed offset value for all humans, so unfortunately we have to make do with this cumbersome method.
- Sara suggested putting 3 flex sensors on the elbow for measuring different points
- Sara's ideal system would be comprised of: (She is
not interested in many lumbar-thoracic details, just
position relative to eachother)
- A fixed sensor on the pelvis- the basis for all measurement
- A sensor on the L4 vertebrae representing the lower lumbar area
- A sensor on the L1 vertebrae representing the upper lumbar area
- A sensor on the T1 vertebrae representing the thoracic spine area.
- Sara will need signal frequency of filter and amplifier range
- Sara will need a zero button for sure- covered, so that clients cannot mistakenly trigger it
- Sara's Wisconsin correspondent is now working on the lumbar region- she will see him shortly and ask more questions
- We can definitely use P10007's mechanical spine test platform to validate our sensors. We can also use Vicon but that would be circular (and more complicated), so she suggested we use the mechanical spine instead.
- Software: Company- Cmotion, Software- Visual 3d
- A product on the market exists using flex sensors for spinal applications, but lacks in rotation
- Skin stretching is a huge issue.
- Wires need a lead!
- Error is 1-2 percent not degrees!