P15073: Autonomous IV Stand - EDGEedge.rit.edu/content/P15073/public/Detailed Design Documents... · Prelim.Test Plan - Mechanical P15073 ... P15073: Autonomous IV Stand 1. Test battery

P15073: Autonomous IV StandDetailed Design

Michael Binger, Caitlin Conway, Nick Goddard, Nick Jacobs, Christina

Pysher, & Ethan Whritenor

Friday December 5, 2014

Topics Covered

● Problem Statement

● CAD Model

● Use Scenarios

● Functional Decomposition

● Bill of Materials Summary

● High and Medium Risk Subsystem Feasibility

● Drawings

● Wiring Diagrams

P15073: Autonomous IV Stand

Current IV Stand

● Insufficient number of hooks

● Pole length is not always adjustable

● Stand can not be taken apart

● Base is too wide for some areas of

hospital

● Difficult for weak patients to transport


Problem Statement

An autonomous intravenous (IV) stand is a device that allows for mobile

medicine distribution without the need for the patient to maneuver the device.

The current IV stand has a large base that causes trip hazards, is limited to four

hooks, and is difficult for weak patients to maneuver. The IV stand became

prominent in the 1950's and the design has not experienced much modification

since then.

The goal of this project is to modify the existing IV stand by developing and

implementing an autonomous system that will follow a patient around a medical

facility. Other projected outcomes include improvements to the design of the

stand such as a smaller base, a detachable base that will attach to a bed or

wheelchair, and provide more IV bag hooks.P15073: Autonomous IV Stand

● Weak patients use IV stands for stability

when walking

● Patients need to manually maneuver IV

stands when walking

Main Problems to Solve

Target Patients

● 13 years and older

● Long term stay (more than a week)

● Low traffic areas

● Weak or post-operation patients

o Patients that require assistance to walk without

using an IV stand for stability

o Not recommended for patients who recently had

abdominal surgery


Scenario 1: Patient goes for walkP15073: Autonomous IV Stand

● Detects patient is

mobile.

● Follows at safe

distance.

● Allows patient

access to proper

support.

Scenario 2: Manually Push IV Stand

● Omni wheels lift up

● Nurse maneuvers IV

stand manually

● Allows for flexibility

of the device

Removed

CAD Model


CAD ModelP15073: Autonomous IV Stand

Omni - wheel function

Here is a short youtube video of the type of wheel system we will be using.


http://youtube.com/v/5vJCucpVdX0

http://youtube.com/v/5vJCucpVdX0

Bill of Materials Summary

● 53 items to be purchased: $1458.10

● Total w/ Estimated Shipping Cost: $1654.24

● 10% Contingency: $145.81

● Estimated Overall Cost: $1800.05

● 4 items already purchased through MSDo $422.32

Questions?


Questions for Dr. DeMartino

● What do you need from us for grant

justification?

● Would we continue to purchase parts through

MSD or would we have to use a different

process through the Innovation Center?


SME: Rob Kraynik

Base Machine Suggestion: Weld It● He will do the welding

● Should look aesthetically pleasing

● Will be easier than forming it

Recommended Dimensions● .060” Al

● Use 6/32 or 8/32 screws to attach base in 8 locations

Scheduling● Stop down first week of spring semester

● They will look at amount of work and provide an estimated completion date

Ensure Driving Wheels Make Contact with the Floor

Ping Sensor Placement

14.2 inches apart

~3.8 inches from the front

centered on the base

Max Height (in.)

74.4

Waist Width (0.191H)

14.2



Prelim.Test Plan - Mechanical


1. Test FEA of UHMW

2. Turn resistance of encoder and potentiometer

Prelim. Test Plan - Electrical


1. Test battery to determine that it provides 24V DC. Test battery with voltage

division circuit to determine the proper voltage and amperage are being

provided to each component.

2. Test motors using power supply.

3. Initial arduino programming and testing with motor shields to determine

functionality and proper outputs to the motors.

4. Initialize communication between arduino and encoders.

5. Initialize communication between arduino and ping sensors.

6. Run independently from laptop.

Prelim. Test Plan - Subsystem


1. Test integration between arduino and motor shields with

actual motors.

2. Test the tether subsystem with arduino logic

3. Test the object detection subsystem with arduino logic.

4. Test motor connector shaft with omni wheels and motors.

Electrical Risks


Electrical Risks


Electrical Risks


Electrical Risks


MSD II Project Plan

MSD II Project Plan

MSD II Project Plan

Planned Meeting Time: Tuesdays 2:00pm - 3:30pm

Questions?


High Risk Subsystems

● Provide Power

● Maintain Proximity

● Avoid Objects

● Deliver IV Bags


Provide Power


Materials to Provide Power


Power Feasibility Calculations


Maintain Proximity


Materials For Drive Sub-System


Feasibility


● 8” Omni-wheels needed instead of 6”

● Omni-wheels enable us to make quick and

accurate adjustments to direction

● Motor provides torque required to move

stand at specified RPM’s

● Motor will mount to the sides of the base

shell

Feasibility

Aluminum Rod-Al 6061

-High yield strength

-Cost effective

-deflection not an issue

Set screw

-fits our design parameters


Feasibility

Pixy Camera - provides unreliable feedback

Encoder - provide constant feedback

Pixy Camera - needed to be tested to understand its capabilities

Encoder - straight forward implementation

Pixy Camera - patient must wear a vest to determine their location

Encoder - patient must wear a belt to determine their location

Both options include an additional tether attached to the patient

for safety

CMU Pixy Camera vs. Tether with Encoder


Feasibility

CMU Pixy Camera vs. Tether with Encoder

We chose the tether with encoder option to detect the

patient due to its straight forward implementation and

its ability to provide constant feedback on the

patient’s position.

Encoder Potentiometer


Material for Following Sub-System


● The 90 degree angle purchased

from McMaster will be machined for

our purposes.

● The sheet metal parts will be cut on

the waterjet from the aluminum

sheet that is also being used for the

cover on the base.

Lower Assembly

● Will be bolted to the base

● A retractable keychain will also bolt

to the aluminum angle

● The rotary encoder will mount to

the angle with the provided panel

nut

Aluminum Angle Needs Machining

● Machine in RIT shop

● The dimensions of the retractable

spool are not currently known

Upper Assembly

● Will affix to the larger telescoping

tube at a specific height from the

ground

● The tether will feed up from the

lower assembly

● The sheet metal arm provides a

moment to easily turn the

potentiometer

Upper Assembly

Pole Flange

● Will be made on the waterjet along

with the base cover and arm

● Will mount to tapped holes on shaft

collar

● Potentiometer will mount from

bottom with panel nut

Sheet Metal Arm

● Will be made on the waterjet

along with the base cover and

pole flange

● The two ends will be bent to 90

degrees as shown

Standoff needs Machining

● The standoff from McMaster will be

machined down to 6mm in order to fit

with shaft coupler that is attached to

the potentiometer

Avoid Objects


Material to Avoid Objects

● Perform measurements between moving

or stationary objects

● Provides precise, non-contact distance

measurements within a 2 cm to 3 m range

● Burst indicator LED shows measurement

in progress

● Simple pulse-in/pulse-out communication


Deliver IV Bags


Materials to Deliver IV Bags


Medium Risk Subsystems

● Provide Feedback

● Manually Maneuver IV Stand (Raise Omni-

Wheels)

● Keeping the Omni-Wheels on the ground


Omni-Wheel Lifting MechanismP15073: Autonomous IV Stand

Provide Feedback


Materials for Providing Feedback


Mechanical Drawings

● Baseo Top Shell

o Flat Bottom

● Motor Lift Plate

● Battery Shelf

● Top pole

● Bottom pole

● Wheel Hub and Drive ShaftP15073: Autonomous IV Stand

Base Top

UHMW Bottom

Motor Lift Sheet

Battery Shelf

Top Pole


Bottom Pole


Wheel Hub and Drive Shaft


Electrical Diagrams


All sensors use a

total of 50 Digital

I/O pins and 4

analog pins

LCD screen and Fan

Motor Connection and Sonic Ping

Pseudo Code


Questions?


What We Want From The Audience

Is there anything that we are failing to consider?

Do you see any challenges with our design we have failed

to observe?


Thank You
