MSD P13038 Hearing Aid Design. MSD 2 Preview March 8, 2012

Transcription

1 MSD P13038 Hearing Aid Design MSD 2 Preview March 8, 2012

2 Team Members Alissa Anderson Team Manager Conor Murphy System Integration Engineer Ronald Dries Lead Electrical Kelly Murosky Lead Mechanical Nanxi Yu EDGE Master Paula Garcia Secretary Eric Lew Budget Master Marbella Vidals Customer Relations Sarah Brownell Guide

3 Functional Decomposition (ME) Key Needs: (2) Fits most adult ears ages years (3) Device does not draw negative attention (4) Device supports an active lifestyle (7) Device is rechargeable by computer USB amplify sound program device accepts data stores data user input recognizes input stores input adjusts system to input process sound output sound capture sound modify sound filter sound adjust by frequency raise sound level supply power accept energy store energy transform energy output energy track power level modify function to data interface with user accept ear fits comfortably protects user resists water and shock controls volume manages heat

4 Product Concept battery enclosure round enclosure transfer module Interface with standard ear tube and ear molds

5 Product Concept battery enclosure micro USB port for power charging button interface detachable Bluetooth module

6 Round Enclosure (No Transfer Module) holes for microphone sound capture outlet for wires to BTE enclosure pin to interface with transfer module for stability micro USB opening - to interface with transfer module pin to interface with transfer module for stability 5 way button up = volume up down = volume down right = profile up left = profile down in = power on/off

7 CAD Proto 1- Rotation Feature Outer blue ring rotates about the main enclosure allowing user to hide the micro-usb hole. Rotation is controlled by grey wire stem. Top Closed Front Closed Proto 2 Changes: (1) Update microphone hole locations (2) Improve ring assembly Top Open Front Open

8 How to attach Transfer Module stability pins (1) rotate blue ring down (3) add transfer module. module will be secured by female micro USB (not shown) and stability pins (2) expose micro usb port (4) wear and enjoy!

9 Battery Enclosure wires to round enclosure micro USB (power charging) Batteries slide out of enclosure when they need to be replaced Proto 2 Changes: (1) Battery Clips (2) PCB Standoffs

10 Types of Ear Molds Oticon Intiga Hearing aid with dome style ear mold Oticon DigiFocus II Hearing aid with custom style ear mold Motorola HK200 Bluetooth Headset, dome style ear mold

11 User Renderings

12 Functional Decomposition (EE) Key Needs: (1) Device amplifies sound (7) Device charges via USB port user input recognizes input amplify sound program device accepts data stores data stores input adjusts system to input process sound output sound capture sound modify sound filter sound adjust by frequency raise sound level supply power accept energy store energy transform energy output energy track power level modify function to data interface with user accept ear fits comfortably protects user resists water and shock controls volume manages heat

13 Round PCB (EE/CE) BTE WIRE ATTACHMENT LOCATION 3 7 STANDOFF HOLE STANDOFF HOLE 3 ITEM NO. PART NUMBER DESCRIPTION QTY. 1 PCB_Round_Feb6 PCB BOARD 1 2 MicroProcessor_FreeS cale FREESCALE MC56F RC_Regtangle SURFACEMOUNT RESISTOR & CAPA 12 4 Speaker KNOWLES ES Microphone_Knolls_TP KNOWLES TD I_A_New INSTRUM AMPLIFIER 1NA333A1DGKT 2 7 microusb_keepout MICRO USB ZX62-AB-5P8 1 Change Date UNLESS OTHERWISE SPECIFIED: NAME DATE Alissa Anderson

14 Battery Layout (EE/CE)

15 Round Circuit Schematic

16 Round PCB Schematic

17 Battery Circuit Schematic

18 Back PCB with Planes Shown

19 Back PCB without Planes Shown

20 Top Layer of Back Piece PCB

21 Bottom Layer of Back Piece PCB

22 Functional Decomposition Key Needs: (1) Device amplifies sound (7) Device charges via USB port user input recognizes input amplify sound program device accepts data stores data stores input adjusts system to input process sound output sound capture sound modify sound filter sound adjust by frequency raise sound level supply power accept energy store energy transform energy output energy track power level modify function to data interface with user accept ear fits comfortably protects user resists water and shock controls volume manages heat

23 Mode Change / Standby Flow Chart (CE)

24 Volume Flow Chart (CE)

25 Sound Modification Flowchart (CE)

26 Programming in Circuit (CE) Programming Options JTAG/ONCE connector SCI (Serial Communication Interface) i2c Major issue is how to program the DSC in the circuit (on the PCB) Possible Solutions Detachable JTAG connector USB to SCI RS232 to SCI JTAG/ONCE also allows for debugging of DSC as well as programming USB or RS232 to SCI requires additional hardware that will need to be built in a separate box. JTAG/ONCE connects to USB port of computer then to the hearing aid.

27 Processing Algorithm (CE) Basic idea behind amplifying sound for this project is to : - Collect samples of human speech - Take the Fourier transform of the samples once a predetermined number has been reached - Walk through samples in the frequency domain and multiply by the gain - Take the inverse Fourier transform of the modified data to bring it back to the time domain - Output result through the DAC to the speaker Sample code from Freescale to perfom an FFT on values in an ADC buffer res = dfr16rfft(prfft, (FRAC16 *) &AdcBuffer[AdcReadIndex], (dfr16_sinplacecrfft *) &FFTInplaceBuf[0]); The sample code takes in a signal performs the FFT and outputs the highest frequency to the terminal.

28 MatLab Code Overview: amplifies sound and reduces noise for a patient with ski-slope hearing loss Frequency Shaper: Breaks hearing loss into piecewise functions and calculates the required gain for each section Applies Fourier Transform on the input signal, and multiplies transformed signal by the required gain function The Inverse Fourier Transform of the signal converts signal back to the time domain. Amplitude Shaper: Output signal is inputted into an amplitude shaper to remove noise and confirms signal is in acceptable (not harmful) range.

29 Proposed Budget Item Qty Cost ea. Total Evaluation Boards 7 $200 $1400 Microphones 5 $0 $0 Microprocessor 3 $5 $15 Amplifier components 1 $70 $70 Speaker 5 $0 $0 USB Interface 1 $20 $20 Rechargeable Battery 10 $15 $150 PCB 4 $100 $400 Acoustic Test Stand 1 $500 $500 3D Printing Costs 7 $75 $525 Customer Survey Incentive 1 $50 $50 Miscellaneous X X $1000 TOTAL $4130

30 Timeline: Critical Dates Date Event DRI Jan 29 order proto 1 enclosure Ali February 15 Printed Circuit Board (PCB) 1.0 Ordered Conor February 18 order proto 2 enclosure Ali March 10 order final PCB Conor March 18 Order final enclosures for integration Ali April 1 Start integration and debug ALL April 26 WORKING PROTOTYPE DUE ALL May 4 Imagine RIT ALL May 10 Final MSD Review (Week 10) ALL

31 TEST PLANS MSD 2 Preview March 8, 2012

32 Test Plans (ME) 1 of Spec # Source Specification Direc tion Units of measure Marginal Ideal Test Plan S8 CN11, CN12 Maximum temperature at outside surface of device min of body temp + 10 body temp Temperature sensor on final product to measure operating temperatures S10 CN4, CN6, CN10, CN11 Weight of earpiece min g <15 <12 weigh final product using scale S18 CN9 Attaches to a standard ear tube and ear mold yes/ no yes/no yes yes Test product with standard ear tub and ear molds S19 CN14 Manufactured cost (estimated) min $ <2000 <1000 Mathematical Analysis

33 Test Plans (ME) 2 of Spec # Source Specification Direc tion Units of measure Marginal Ideal Test Plan S9 CN2, CN4, CN11 Range of adult ear size accommodated max percentile 25th to 75th 5th to 95th Heuristic Analysis Dimensional Analysis to prove the final product S14 CN3 Percent of surveyed people who identify a picture of the device as something other than a hearing aid. max percent >60 >80 Heuristic Analysis S15 CN3 Percent of surveyed hard of hearing people who prefer the form of the new device to standard behind the ear hearing aids max percent >50 >75 Heuristic Analysis S16 CN3 Percent of surveyed hearing people who would use the device for Bluetooth or music listening max percent >50 >70 Heuristic Analysis S17 CN11 Percent of surveyed people who feel the device is comfortable to wear max percent >60 >80 Heuristic Analysis

34 MSD 1 Unit Test Plans (EE/CE) Test EE/CE Test Description Expected Outcome Equipment Needed Microphone Unit Test EE This test will test the functionality of the microphone. We will setup a microphone and connect its ouputs to an oscilloscope. Then observe the output as we talked into it We will see what the output of the microphone is and be able to determine if the level of output from the micophone is too high for the ADC on the DSC. Also we will get a better understanding of how the microphone works. Also determine how the outputs of the two mics is different Oscilloscope Microphone Speaker Unit Test EE This will test the functionality of the speaker. A speaker will be setup and we will connect its input to a signal generator. We will then be able to observe how the speaker works The expected outcome of this test is to determine that the speaker functions, and what kind of amplitude is required to make the speaker function. Waveform Generator Oscilloscope Speaker Bandpass filter and Pre- Amplification Test EE This will test the functionality of the bandpass RC filter and the preamplification instrumentation amplifier. We will test the system by applying signals of varying frequency and amplitude, and measuring the output signals produced. The expected output of the test should be a reduction in amplitude of frequencies outside of our desired range of 200Hz-800Hz, with the amplitude of the output signal before amplification being less than one-half of the input signal. We should also see desired frequencies amplified to a level in which they can be evaluated by the ADCs of the DSC. Breadboard, Oscilloscope, Waveform Generator, Instrumentation Amplifier, Resistors and capacitors of desired values Battery Charger Unit Test EE The battery charger will be wired up on a breadboard like it will be in the final circuit. We will then apply the correct input voltage to the battery charger circuit and attempt to charge the batteries that we purchased. This will show us that the battery charger functions properly. This test will be performed by measuring the batteries during charging to see if they are actually charging, then discharging the batteries in a way similar to the device's operation. We can also experiment with the battery charging circuit to make it as optimized as possible. Battery Charger IC Batteries Breadboard Multimeter

35 MSD 1 Unit Test Plans (EE/CE) Test EE/CE Test Description Expected Outcome Equipment Needed Battery Charger/ Battery connected to DSC EE/CE Connect the battery charger circuit/ batteries to a breakout board for the DSC This test will make sure that the DSC can be powered by the batteries, and show that there aren't any problems with the battery charging battery system when connected with the DSC Batteries Battery Charger Circuit Freescale DSC Eval Board Multimeter Test the 5-Way Tactile Switch EE/CE This test will prove the functionality of the switch. The switch will be wired up on a breadboard. Then it will be probed as the different directions are pressed to determine the output of the switch. We will have a clear understanding of how exactly the switch works after this test. As well 5-Way Tactile Switch as we will know if the switch is active high or Multimeter active low which will be needed for when we use the switch to detect button presses Integration Testing Evaluation boards EE/CE Connect the microphone, speaker, and switch to the DSC connect the microphone input, and the output of the DSC to an oscilloscope. This will take the functioning units that we previously tested and begin to test them as a whole. The point of this is to use the microphone to input actual speech to the DSC and observe how the processing algorithm works for actual speech. Changes/ tweaks will be made to optimize the output. Oscilloscope Microphone Speaker Freescale DSC Eval Board 5-way Tactile Switch PCB Testing 1 EE/CE First protoype PCB's will be connected together and tested to show correct operation of components, Also test programming of DSC The batteries power the circuit as required, the usb charging functions, the DSC can be programmed and runs the same as when using the eval board. Initial PCB's Oscilloscope Multimeter

36 MSD 1 Unit Test Plans (EE/CE) Test EE/CE Test Description Expected Outcome Equipment Needed Test ADC/ ADC interrupt CE Put a simple signal/sinusoid into the Freescale DSC eval board to determine that the ADC is configured correctly and that an interrupt can be generated and handled. Measure the signal before putting it into the ADC to ensure it does not burn anything The signal will generate an interrupt on the ADC pin and call and interrupt service handler. This will ensure that we can detect ecternal events coming into the system on the ADC port SignalGenerator Freescale DSC Eval Board Oscilloscope/Multimeter Test GPIO/ GPIO interrupts CE The switch will be wired up to the GPIO ports defined for the different functions that we would like to implement. We will then move the switch to determine that each of the interrupts is generated as we had design them to work. If we can detect and handle all of the interrupts from the switch then we know that this functionality is working and the ports and pins that we had chosen for each of the functions is working correctly 5-Way Tactile Switch Freescale DSC Eval Board Test Volume Adjust CE Put a simple signal into the the ADC of the Eval kit, the interrupts have already been tested at this point so this will be testing the interrupt service routine, or the interrupt handler. The volume button will be pressed up and down to simulate the user changing the volume level The output signal should vary from the input signal according to if the volume is increased or decreased. The input and output of the system will be shown pn an oscilloscope and the output should avry with the volume level selected. Signal Generator Oscilloscope 5-Way Tactile Switch Freescale DSC Eval Board

37 MSD 1 Unit Test Plans (EE/CE) Test EE/CE Test Description Expected Outcome Equipment Needed Test Mode Select CE Put a simple signal into the the ADC of the Eval kit, the interrupts have already been tested at this point so this will be testing the interrupt service routine, or the interrupt handler. The mode button will be pressed right and left to simulate the user changing the mode The outpust signal should vary depending on what mode the user is currently in/switched too. The modes will vary the non volume adjusted gains of the hearing aid, so the signal should vary much like the volume is being adjusted, just with the volume level set to 0. Signal Generator Oscilloscope 5-Way Tactile Switch Freescale DSC Eval Board Test Standby CE Press the tactile switch in to put the hearing aid into a standby/power down mode. The hearing aid should go into a powered down state and no processing should be done at this point. TO return back into a processing state the switch must be pressed again. 5-Way Tactile Switch Freescale DSC Eval Board Initial Sound Processing Test CE Put a simple signal into the ADC of the eval kit, measure the input signal and output signal on an oscilloscope to visualize how the sound is being manipulated by the DSC The output signal should be amplified by a value determined by the gain we would like to have for the system. This will give an indication of how exactly the processing is working on a simple test signal. We can then experiment with the sound processing to tweak it or add to it. With the simple signal it should be easier to implement and see the result of the processing. Oscilloscope Signal Generator Freescale DSC Eval Board

38 SPEC TEST PLAN (EE/CE) Spec # Source Specification Direction Units of measure Marginal Ideal Test Plan S1 CN1 Lowest level of sound detected min db <60 <30 Place microphone and speaker into Audiologist Test equipment run low sound scenario and see hearing aid response S2 CN1 Frequencies amplified max Hz Place microphone and speaker into Audiologist Test equipment and look at response of the hearing aid to the input S3 CN1, CN6 Maximum amplification target db Place Mic and Speaker into test equipment, set gain to max and observe output response graph S4 CN5 Levels of volume adjustment max levels 5 20 Â Put simple sinusoid into hearing, probe input and output. See how output changes with different volume levels S5 CN7 Time to charge earpiece min minutes <60 <30 Record the time to charge product S7 CN7 Connects to standard USB 2.0 computer port target yes/no yes/no yes Plug hearing aid into USB 2.0 port. Measure voltage/current from battery charger to determine if batteries are charging S12 CN8 Earpiece battery life at maximum amplification max hours >16 >48 Run product at max power andâ record the battery life

39 KEY RISKS MSD 2 Preview March 8, 2012

40 Key Risks (ME) ID Risk Item Effect Cause Likeli hood Severit y Impo rtanc e Action to Minimize Risk Owner 8 Parts break during system integration Prototype (or final product) cannot be assembled; schedule pushed back Failure to work carefully with parts; poor material choice; failure of EE and ME teams to communicate with part sizes Work carefully with finished parts; During alpha and beta prototypes, work with a variety of materials and companies to find best quality; order multiple prototypes and electrical components to replace broken parts Conor 9 Parts do not assemble Prototype (or final product) cannot be assembled; schedule pushed back Failure to review CAD and complete full tolerance analysis; failure of EE and ME teams to communicate with part sizes Complete full tolerance analysis and CAD review prior to ordering final 3D print Kelly 22 Unable to create Button Interface that meets space constraints and is water resistant Cannot interface part electrically; miss waterproof customer need Poor switch device choice Prototype with button; research more options for waterproofing connection Ali Anderson, Nanxi Yu 26 Rapid Prototyping tolerances Design will not be with in specifications; parts will not assembly 3D printing company cannot support required tolerances Seek advice from experts. Research companies and obtain quotes. Kelly Murosky

41 Key Risks (EE) ID Risk Item Effect Cause Likeli hood Severit y Impo rtanc e Action to Minimize Risk Own er 27 PCB Company cannot cut custom edges Team will be forced to re-design PCBs to accommodate straight edges; changing the board shape may hinder EE ability to properly route traces Failure to research PCB process prior to creation Call PCB company and confirm manufacturing abilities. Change companies or adjust board prior to ordering Eric 28 PCB software is only supported by a single company (PCB Express) Team is forced to order board from PCB Express; cannot look for alternative price, manufacturing options, etc. Failure to research PCB process prior to creation Cannot avoid risk based on team decision to use PCB Express. Eric 29 PCB Express does not assemble boards Team will be forced to hand-solder surface mount components Choosing a company that does not support PCB assembly Call PCB Express and verify if they support assembly; if they do not, team must investigate surface mount support on campus Eric 30 Freescale chip requires additional hardware to reprogram Product loses ability to be reprogramed (deliverable) Miss-reading the Freescale chip documentation Contact Freescale immediately and research reprograming options. Ron

42 Updated Team Risks ID Risk Item Effect Cause L S I Action to Minimize Risk Owner 13 Loss of team member (ex: last minute coop) Team loses knowledge and creates more work for other team members. Cause may be due to graduation requirements / personal class choices / personal emergency Cross train between positions. Team manager should be aware of everyones' projects and responsibilities (in the event that one team member leaves, the team manager can help divide the extra work and reassign responsibilities) by checking edge for on a weekly basis to ensure each member updates their documentation. Prior to exit, exiting member should review with the team and transfer all knowledge (if possible). Alissa Anderson 14 Project exceeds budget allowance ($5000) Team can no longer financially continue with project Team member other then "budget master" made unapproved purchase; parts are more expensive than anticipated; emergency purchases are more expensive due to overnight shipping Track expenses and purchase items; Budget Master makes and records all purchases Eric Lew 15 Team member overloaded with work outside of MSD Team loses support from stressed team member (external to MSD) team members should be constantly aware and proactive about academic schedules to foresee high stress work weeks. team members should vocalize stress / busy weeks to team and team manager so that their responsbile MSD responsibilities can be reassigned or other team members can assist Alissa Anderson, Kelly Murosky, Ronald Dries, Conor Murphy, Paula Gracia,Nanxi Yu, Eric Lew, Marbella Vidals