Team Members 2.1.13 Alissa Anderson Team Manager Conor Murphy System Integration Engineer Ronald Dries Lead Electrical Kelly Murosky Lead Mechanical MSD P13038 Hearing Aid Design Detailed Design Review February 8, 2012 Nanxi Yu EDGE Master Paula Garcia Secretary Eric Lew Budget Master Marbella Vidals Customer Relations Sarah Brownell Guide Agenda 2.1.13 Project Overview (5 minutes) - Welcome Mechanical Design Review (30 minutes) - Enclosure review (function, assembly) - Assembly Review - Hot Topic: Assembly Feedback Electrical Design (40 minutes) - Electrical Feasibility - Circuit Schematic Review - Printed Circuit (PCB) Review - Hot Topic: Schematic Review Mechanical Software Design (40 minutes) - Software Flowchart Review - Programming In Circuit - Processing Algorithm - Hot Topic: Programming in Circuit Project Plan (5 minutes) - Critical Path - Budget review
Functional Decomposition (ME) 1.11.13 Key Needs: (2) Fits most adult ears ages 15-25 years (3) Device does not draw negative attention (4) Device supports an active lifestyle (7) Device is rechargeable by computer USB user input recognizes input Product Concept 1.2.13 battery enclosure amplify sound program device accepts data stores data stores input adjusts system to input modify function to data process sound output sound capture sound supply power accept energy interface with user accept ear round enclosure modify sound filter sound adjust by frequency raise sound level store energy transform energy output energy track power level fits comfortably protects user resists water and shock controls volume manages heat transfer module Interface with standard ear tube and ear molds Round Enclosure (No Transfer Module) 2.1.13 CAD Proto 1- Rotation Feature 2.1.13 pin to interface with transfer module for stability micro USB opening - to interface with transfer module pin to interface with transfer module for stability holes for microphone sound capture outlet for wires to BTE enclosure 5 way button up = volume up down = volume down right = profile up left = profile down in = power on/off 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
How to attach Transfer Module 2.1.13 Battery Enclosure 2.1.13 stability pins (1) rotate blue ring down wires to round enclosure micro USB (power charging) (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! Batteries slide out of enclosure when they need to be replaced Proto 2 Changes: (1) Battery Clips (2) PCB Standoffs Proto-2 Change List 2.6.13 User Renderings 1.2.13 Planned Changes as of February 7, 2012 (1) add PCB standoffs to bottom round enclosure and battery case (2) add standoff location for 5-way switch (3) increase size of transfer module and improve transfer module / enclosure interface (4) update tube interface and solidify ear mold attachment plan (5) Add battery clips H C A F E D B G
Material Selection 2.6.13 Material Properties 2.6.13 Sabic s Cycolac acrylonitrile-butadiene-styrene (ABS) thermoplastic resin Grade MG94 Superior flow, injection molding ABS Good impact resistance Best for thin-wall applications Medical biocompatibility Gamma and ethylene oxide (EtO) sterilization properties FDA and ISO 10993 compliant Chemical resistance Flame-retardancy that meets regulatory and safety standards Handles temperatures up to 110 C Broad range of colors Test Plans (ME) 1 of 2 2.1.13 Test Plans (ME) 2 of 2 2.1.13 Spec # S8 S10 S18 Source CN11, CN12 CN4, CN6, CN10, CN11 CN9 Specification Maximum temperature at outside surface of device Direc tion min Units of measure of Marginal Ideal Test Plan body temp + 10 body temp Weight of earpiece min g <15 <12 Attaches to a standard ear tube and ear mold yes/ no yes/no yes yes Temperature sensor on final product to measure operating temperatures weigh final product using scale Test product with standard ear tub and ear molds Spec # S9 S14 S15 Source CN2, CN4, CN11 CN3 CN3 Specification Range of adult ear size accommodated Percent of surveyed people who identify a picture of the device as something other than a hearing aid. Percent of surveyed hard of hearing people who prefer the form of the new device to standard behind the ear hearing aids Direc tion Units of measure max percentile 25th to 75th Marginal Ideal Test Plan 10th to 90th Heuristic Analysis Dimensional Analysis to prove the final product max percent >60 >80 Heuristic Analysis max percent >50 >75 Heuristic Analysis S19 CN14 Manufactured cost (estimated) min $ <2000 <1000 Mathematical 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
Key Risks (ME) 2.1.13 ID Risk Item Effect Cause Likeli Severit Impo hood y rtanc Action to Minimize Risk e 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 2 3 6 Work carefully with finished parts; During alpha and beta prototypes, work with a variety of materials and companies to Conor find best quality; order multiple prototypes and electrical components to replace broken parts 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 2 3 6 Complete full tolerance analysis and CAD review prior Kelly to ordering final 3D print EE 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 2 3 6 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 2 3 6 Seek advice from experts. Research companies and obtain quotes. Kelly Murosky Functional Decomposition (EE) 1.11.13 Round PCB (EE/CE) 2.1.13 Key Needs: (1) Device amplifies sound (7) Device charges via USB port user input recognizes input 3 6 5 7 BTE WIRE ATTACHMENT LOCATION STANDOFF HOLE amplify sound program device accepts data stores input adjusts system to input 3 stores data 6 process sound output sound capture sound modify sound filter sound adjust by frequency raise sound level modify function to data supply power interface with user accept energy accept ear store energy fits comfortably transform energy protects user output energy resists water and shock track power level controls volume 4 1 2 STANDOFF HOLE ITEM NO. PART NUMBER DESCRIPTION QTY. 1 PCB_Round_Feb6 PCB BOARD 1 2 MicroProcessor_FreeS cale FREESCALE MC56F9006 1 3 RC_Regtangle SURFACEMOUNT RESISTOR & CAPA 12 4 Speaker KNOWLES ES-23127 1 5 Microphone_Knolls_TP 24605000 KNOWLES TD-24618 1 6 I_A_New INSTRUM AMPLIFIER 1NA333A1DGKT 2 7 microusb_keepout MICRO USB ZX62-AB-5P8 1 Change Date UNLESS OTHERWISE SPECIFIED: NAME DATE 3 Alissa Anderson manages heat
Battery Layout (EE/CE) 2.1.13 MSD 1 Unit Test Plans (EE/CE) 2.1.13 Test EE/CE Test Description Expected Outcome Equipment Needed Microphone Unit Test Speaker Unit Test EE 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 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 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 Microphone better understanding of how the microphone works. Also determine how the outputs of the two mics is different 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 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,, 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 MSD 1 Unit Test Plans (EE/CE) 2.1.13 Round Circuit Schematic 2.1.13 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 Batteries This test will make sure that the DSC can be Battery Charger Circuit powered by the batteries, and show that there aren't any problems with the battery charging battery system when connected with the DSC Multimeter Test the 5-Way Tactile Switch EE/CE This test will prove the functionality of We will have a clear understanding of how the switch. The switch will be wired up exactly the switch works after this test. As well 5-Way Tactile Switch on a breadboard. Then it will be probed as we will know if the switch is active high or Multimeter as the different directions are pressed active low which will be needed for when we to determine the output of the switch. 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. Microphone Speaker 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 Multimeter
Round PCB Schematic 2.1.13 Battery Circuit Schematic 2.1.13 Back PCB with Planes Shown 2.1.13 Back PCB without Planes Shown 2.1.13
Top Layer of Back Piece PCB 2.1.13 Bottom Layer of Back Piece PCB 2.1.13 Key Risks (EE) 2.1.13 ID Risk Item Effect Cause Likeli hood Severit y Impo rtanc Action to Minimize Risk e Own er 27 PCB Company cannot cut custom edges Team will be forced to re-design PCBs to accommodate straight Failure to research edges; changing the PCB process prior to board shape may creation hinder EE ability to properly route traces 3 3 9 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 3 1 3 Cannot avoid risk based on team decision to use PCB Express. Eric CE 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 3 2 6 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 3 3 9 Contact Freescale immediately and research reprograming options. Ron
Functional Decomposition 1.11.13 Mode Change / Standby Flow Chart (CE) 2.6.13 Key Needs: (1) Device amplifies sound (7) Device charges via USB port amplify sound program device accepts data user input recognizes input stores input adjusts system to input process sound stores data modify function to data output sound capture sound modify sound supply power accept energy store energy transform energy interface with user accept ear fits comfortably filter sound adjust by frequency raise sound level output energy track power level protects user resists water and shock controls volume manages heat Volume Flow Chart (CE) 2.6.13 Sound Modification Flowchart (CE) 2.6.13
Programming in Circuit (CE) 2.6.13 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. Processing Algorithm (CE) 2.6.13 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. MSD 1 Unit Test Plans (EE/CE) 2.1.13 Test EE/CE Test Description Expected Outcome Equipment Needed MSD 1 Unit Test Plans (EE/CE) 2.1.13 Test EE/CE Test Description Expected Outcome Equipment Needed Test ADC/ ADC CE interrupt Put a simple signal/sinusoid into the Freescale DSC eval board to determine The signal will generate an interrupt on the SignalGenerator that the ADC is configured correctly ADC pin and call and interrupt service handler. and that an interrupt can be generated This will ensure that we can detect ecternal and handled. Measure the signal before events coming into the system on the ADC /Multimeter putting it into the ADC to ensure it does port not burn anything Test Mode Select CE Put a simple signal into the the ADC of The outpust signal should vary depending on the Eval kit, the interrupts have already what mode the user is currently in/switched been tested at this point so this will be too. The modes will vary the non volume testing the interrupt service routine, or adjusted gains of the hearing aid, so the signal the interrupt handler. The mode button should vary much like the volume is being will be pressed right and left to simulate adjusted, just with the volume level set to 0. the user changing the mode Signal Generator 5-Way Tactile Switch 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 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 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 5-Way Tactile Switch 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. Signal Generator
MSD 2 Product Test Plans (EE/CE) 2.1.13 MSD 2 Product Test Plans (EE/CE) 2.1.13 Spe c # Sourc e Specification Direction Units of measure Marginal Ideal Test Plan 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 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 300-7000 85-8000 Place microphone and speaker into Audiologist Test equipment and look at response of the hearing aid to the input S2 CN1 Frequencies amplified max Hz 300-7000 85-8000 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 85-95 90 Place Mic and Speaker into test equipment, set gain to max and observe output response graph S3 CN1, CN6 Maximum amplification target db 85-95 90 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 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 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 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 S12 CN8 Earpiece battery life at maximum amplification max hours >16 >48 Run product at max power andâ record the battery life Proposed Budget 1.11.13 Timeline: Critical Dates 2.1.13 Item Qty Cost ea. Total Evaluation s 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 $175 $175 Miscellaneous X X $1000 TOTAL $4255 Date Event DRI Jan 29 order proto 1 enclosure Ali February 15 Printed Circuit (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
Updated Team Risks 2.1.13 ID Risk Item Effect Cause L S I Action to Minimize Risk Owner 13 14 15 Loss of team member (ex: last minute coop) Project exceeds budget allowance ($5000) Team member overloaded with work outside of MSD Team loses knowledge and creates more work for other team members. Cause may be due to graduation requirements / personal 2 3 6 class choices / personal emergency Team member other then "budget master" Team can no made unapproved longer purchase; parts are financially more expensive than continue with anticipated; emergency project purchases are more expensive due to overnight shipping 1 3 3 Team loses support from stressed team member (external to MSD) 2 3 6 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). Track expenses and purchase items; Budget Master makes and records all purchases Alissa Anderson Eric Lew team members should be constantly aware Alissa Anderson, and proactive about academic schedules to Kelly Murosky, foresee high stress work weeks. team Ronald Dries, members should vocalize stress / busy weeks Conor Murphy, to team and team manager so that their Paula Gracia,Nanxi responsbile MSD responsibilities can be Yu, Eric Lew, reassigned or other team members can assist Marbella Vidals Backup MatLab 1.11.13 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. Types of Ear Molds 1.9.13 Amplitude Shaper: Output signal is inputted into an amplitude shaper to remove noise and confirms signal is in acceptable (not harmful) range. Oticon Intiga Hearing aid with dome style earmold Oticon DigiFocus II Hearing aid with custom style earmold Motorola HK200 Bluetooth Headset, dome style earmold
Customer Needs 1.11.13 Specifications 1.11.13 Customer Need Rank Description Spec # Source Specification Direction Units of measure Marginal Ideal Notes DRI CN1 9 The device amplifies sound S1 CN1 Lowest level of sound detected min db <60 <30 lowest range of normal hearing EE CN2 9 The device fits most adult ears ages 15-25years S2 CN1 Frequencies amplified max Hz 300-7000 85-8000 marginal values are those used in radio, 85 is lowest male voice EE CN3 9 The device does not draw attention to the user as a hard of hearing individual S3 CN1, CN6 Maximum amplification target db 85-95 90 max considered safe EE CN4 9 The device supports an active lifestyle (stays on the ear during everyday activities and light activities) S4 CN5 Levels of volume adjustment max levels 5 20 adjusted in steps or continuous EE CN5 9 The device includes a way for the user to adjust the volume while on the ear S5 CN7 Time to charge earpiece min minutes <60 <30 EE CN6 9 The device is safe to use S7 CN7 Connects to standard USB 2.0 computer port target yes/no yes/no yes EE CN7 9 The device is rechargeable by computer USB port S8 CN11, CN12 Maximum temperature at outside surface of device min of body temp + 10 body temp MEEE CN8 3 The power in the earpiece should lasts at least 48 non-continuous hours S9 CN2, CN4, CN11 Range of adult ear size accommodated max percentile 25th to 75th 10th to 90th ISE CN9 3 The device interfaces with a standard tube and ear mold S10 CN4, CN6, CN10, CN11 Weight of earpiece min g <15 <12 marginal values will depend on ergonomic info ISE CN10 3 The weight of the device is similar to existing earpieces S12 CN8 Earpiece battery life at maximum amplification max hours >16 >48 EE CN11 3 The device is comfortable to wear S14 CN3 Percent of serveyed people who identify a picture of the device as something other than a hearing aid. max percent >60 >80 team should conduct surveys (at imagine RIT? thoughts?) ID CN12 3 The device does not generate excessive heat during use or charging CN13 1 The device includes an additional method for toggling between functions (for later use to switch between programs or turn on Bluetooth, etc.) S15 S16 CN3 CN3 Percent of surveyed hard of hearing people who prefer the form of the new device to standard behind the ear hearing aids Percent of surveyed hearing people who would use the device for Bluetooth or music listening max percent >50 >75 team should conduct surveys ID max percent >50 >70 team should conduct surveys ID CN14 1 The device has a cost similar to current devices when in production S17 CN11 Percent of surveyed people who feel the device is comfortable to wear max percent >60 >80 team should conduct surveys ID CN15 0 Optional: The device communicates with a cell phone or music player by Bluetooth S18 CN9 Attaches to a standard ear tube and ear mold yes/no yes/no yes yes maybe should interview audiologist for final decision ID CN16 0 Optional: The device has noise cancellation capabilities S19 CN14 Manufactured cost (estimated) min $ <2000 <1000 not as important in first round of prototyping, but should be considered ISE Proto 2 Change List 2.1.13