Author
Poster for Design Day
Apr. 16, 2019—The poster that will be presented in our final presentation on 04/22/2019 is attached below and was used for consideration in design meetings on 04/10/19 and 04/17/19. BME_5 Design Day Poster
PID Final Validation in Servo Construct
Apr. 16, 2019—Because of the differences in state seen between the prosthesis and the servo motor used as a proof of concept, two distinct PIDs were constructed for clinical use and for servo validation. The intial PID was formed based on pre-existing arduino libraries, but the analog output, did not translate as smoothly as our matlab model...
Validation Data for Software
Apr. 16, 2019—Final device validation, performed with software and hardware constructs with servo motor actuation model. The first graph illustrates the ability for the software to accurately determine the user intended action for future actuation. The final graph shows the distribution of action across the three main elements of the software: mean absolute value of differential EMG...
Safety Design Considerations
Apr. 3, 2019—A risk analysis was performed previously during Grant development and is shown above. Probability of Safety Event: 1 = extremely unlikely, 10 = guaranteed Severity of Safety Event: 1 = no harm to the user, 10 = fatal
Gesture Classifier Possible Fits
Apr. 3, 2019—Preprocessed emg data from the current hardware landscape with varied percent contractions across three subjects was taken and used to train a gesture classifier for software implementation. The three fits shown below were considered for use in the current scheme. The third order polynomial presented too much variation at the extremes of the data set...
SNR Recalculations
Apr. 3, 2019—SNR values were previously recalculated given changes in baseline considerations from previous studies, as well as, with outputted data from the software preprocessing system to assess are ability to achieve similar SNR in real time, to that seen in previously manually filtered data. We found the values shown below which remained consistent with previous tests,...
Comparison Teensy Processed Data to Raw Signal
Apr. 3, 2019—Software Development Progress with inputted Signals On the left above is the output from the Teensy v3.6 analog pin following intake of raw signals from the EMG microcontrollers, shown on the right, and processing using a Tustin Approximation in the developed software system. Varying contraction levels are evident throughout the approximation as well as varied...
Progress Report 6 (2/27/19)
Feb. 26, 2019—Previous Goals We had previously strived to continue hardware addition and construction with battery pack incorporation and the identification of myoware sensor processing issues. We also aimed for translation and effective implementation of PID controller in arduino IDE. EMG testing was begun and we hoped to continue the identification of effective phantom users and become...
Weekly Meeting 10 (2/18/19)
Feb. 19, 2019—Prosthetic Hand Update Kevin (contact from Emily) connected with third party in the US who should be able to identify correct path moving forward For time’s sake: SERVO Motor to be ordered this week Need to match properties of the hand PWM actuation Hold angle once the signal ceases as current velocity-based systems do Algorithm...
Serial Output for Myoware Sensors
Feb. 13, 2019—First Visualization of Myoware Sensors The relative ports for each of the myoware input/outputs for serial observation of the output forms. This is without internal feedback, that is each sensor is outputting to independent analog ports to be read. Theoretically, both sensor positive nodes could be soldered to the same 3.3 V node in the...
Progress Report 5 (2/13/19)
Feb. 12, 2019—Previous Goals Our prior goals included writing a protocol for EMG studies with myoware sensors (such as how to test and where to place electrodes). We also strived to investigate EMG signal interpretation and analysis, reading existing literature to map expectations of movement. We further investigated PID behavior with manipulated variables creating sine and step...
PID Observations
Feb. 10, 2019—PID Observations General behavior Characteristics: Higher Proportional Control = Operates at defined setpoint Higher fraction control here to force the fight between muscle activation and relaxed hand posture Lower Proportional Control = Infinite rise in output value (operating in the single digits results in 10^6 outputs) Higher Integral Control = Infinite rise in value although...
Initial PID Behavior Observation MatLab Code
Jan. 29, 2019—Matlab Code used for initial PID behavior observation. Several different constants and graphical outputs were observed with a step function to see how the controller outputs would change with time. Will be used if Matlab communication with teensy board is made available through Matlab features Useful information regarding MatLab to arduino transformation: https://www.mathworks.com/help/supportpkg/arduinoio/getting-started-with-matlab-support-package-for-arduino-hardware.html % PID...
PID Controller Notes
Jan. 20, 2019—Resources: https://www.omega.com/prodinfo/pid-controllers.html https://www.omega.com/prodinfo/how-does-a-pid-controller-work.html https://www.quora.com/How-would-I-implement-a-PID-controller-code-in-a-microcontroller https://en.wikipedia.org/wiki/PID_controller#/media/File:PID_en.svg
BMEideas Grant Proposal
Oct. 29, 2018—A grant proposal for the BMEideas program will be completed based on this project throughout the semester and posted here: BMEIdeas Proposal
Progress Report 1 (11/01/18)
Oct. 29, 2018—Background Current commercially available myoelectric prostheses operate using a velocity-based controller mechanism, which does not accurately represent the relationship between intact muscle activation and hand motor function. This limits the validity of experimental comparisons between the prosthesis and intact hand. In an intact motor control system, continuous active muscle drive is required for motion and...