P16041: Smart Walker IV/public/
Table of Contents
Phase Goals and Accomplishments
- Develop a fuller understanding of the current state of the system
- Compiled a comprehensive list of all sensors and their purposes
- Assessed the drivetrain and clutch system
|Date||Person Interviewed||Role||Questions and Responses|
|February 10, 2016||David Malanga||Smart Walker III EE||Notes|
|February 23, 2016||Kailee Polimeni||Smart Walker III ME||Notes|
High Level Block Diagram
High Level Schematic
Current Design Analysis
- Can the system operate at 12V as opposed to 24V?
- Measure current draw
- Measure torque
- Can the clutch operate as required?
- Alignment and mounting of the electromagnetic clutch
Seat Load Cell Uses
- Off balance seating does not necessarily imply
pressure sore development
- This is only one of 6 parameters used in the Braden Scale
- Questionable repeatability when weighing a patient
- Would require routine calibration
|Smart Walker IV||Measure vitals, Fall detection, Autonomous navigation, bed sore prediction|
|Siemens C-Walker||Assist user movement, Obstacle avoidance, High level mapping software|
|FlexiForce Walker||Diagnosing muscle or nerve problems based on changes in grip strength|
|VTT IoT Walker||
Heart Rate Detection
|Detection Method||Accuracy||Ease of Measurement||Lighting||Skin Tone||Distance From Camera||Measurable Range|
|Metal Hand Sensors||±1 bpm||Hold handles||n/a||n/a||n/a||40-240 bpm|
|Measurement Method||Accuracy||Technical Concerns||Medical Relevance|
|Metal Handles||~4% error||Very specific measurement position, see image below||Debatable usefulness|
|Device||Release Date||Processor||Architecture||Cores, Speed||Memory||I2C, SPI, GPIO?||Cost||Notes|
|PandaBoard ES||2011||OMAP4460||ARM Cortex A9||2, 1.2GHz||1GB LPDDR2||Yes, Yes, Yes||~$182||Currently on SWIII|
|Raspberry Pi 2-B||2015||BCM2836||ARM Cortex A7||4, 900MHz||1GB LPDDR2||Yes, Yes, Yes||~$40|
|Raspberry Pi 3-B||2016||BCM2837||ARM Cortex A53||4, 1.2GHz||1GB LPDDR2||Yes, Yes, Yes||~$40||Just released, potential alternative|
|Intel Galileo Gen. 2||2014||Quark X1000||P54C/i586||1, 400MHz||256MB||No, No, Yes||~$80||Underpowered, too little I/O|
|Intel NUC||2015||Core i7-5557U||Intel x86||2, 3.1GHz||Up to 16GB||No, No, No||~$400-500||Expensive, too little I/O|
|ODROID-XU4||2015||Exynos5422||ARM Cortex A15||4, 2GHz||2GB LPDDR3||Yes, Yes, Yes||~$74||High power consumption|
|BeagleBone Black||2013||AM3359||ARM Cortex A8||1, 1GHz||512 MB DDR3L||Yes, Yes, Yes||~$55|
- Mechanical drivetrain completion
- Machine shop is typically very busy
- Potentially faulty design
- New design has not been tested
- ROS integration potentially unnecessary
- Could create a time issue
- PandaBoard model is over 5 years old
- Could be difficult to acquire the same model if more Smart Walkers are built
- Could be expensive to purchase more boards
To view the updated document, see Risk Assessment.
Plans for next phase
- Find out how to interface with the PandaBoard
- Meet with previous team members
- Take sensor inventory
- Test all sensors to determine degree of functionality
- Plan what needs to be done to fix any sensor issues
- Research into low level vital signs algorithm development
- Create a completion plan for the drivetrain and clutch system
Heart Rate DetectionFor a basic description of how heart rate measurement works with metal handles, see information here.
To see the research on the camera based method developed by MIT, see the article here.
To see some numerical data on handle based heart rate detection, see the data for this product.
BMI SensorFor a basic description of how BMI measurement works, see this information.
To see the top 5 most accurate BMI measurement methods, see this article.
To see the type of device used by the Smart Walker IV, see data here.
To read up on what BMI is and what it can be used for, see the data here and here.