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Supporting parental contact for preterm infants

MAE 156B – Fall / Winter 2024-2025

Mayah Carlton, Reuven Reyman, Jeffrey Keppler, Parissa Teli, Mike Zhang

Design & Risk Management Report

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Problem Background

For Internal Use Only. Do not Distribute. Slide 2

10% of Pregnancies – result in preterm births
Skin to Skin Contact – Proven to benefit preterm infants

Challenges

Large number of tubes and accessories connected to infant
Probability of unintentional disconnect of tubes is high
Many hands needed to transfer infant from incubator to parent
Parents and doctors are nervous for the baby’s safety during and after transfer

Mayah

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Current Transfer Procedure

For Internal Use Only. Do not Distribute. Slide 3

Mayah

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Design Requirements

For Internal Use Only. Do not Distribute. Slide 4

Mayah

Fundamental Requirements	Constraints
The device shall maintain a predetermined distance between infant and jet ventilator box during the entirety of the transfer and kangaroo care time The device shall incorporate secure, adjustable support mechanisms that can bear the weight of the device components and an infant with a factor of safety ≥4* The device mount shall be compatible with standard NICU equipment	The device must integrate with existing tubes and accessories of the ventilator and other equipment Components in and near sterilized areas must be sterilizable Materials used must comply with medical safety standards

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System Design

For Internal Use Only. Do not Distribute. Slide 5

Reuven

Rail Mount

Can Pivot

Linkage Pair I

Can Rotate

Center Hub

Shoulder Mount

Can Pivot

Accessory Holder

Can Pivot and move up/down

Linkage Pair II

Can Rotate

Mounting Hub

Payload Hub

The KangaMove system is essentially a linkage arm responsible for managing the various ventilator tubes and accessories connected to the infant during and after transfer from the incubator to the parent.

The design features locking joints to assist doctors by keeping the arm in place while equipment is moved around, this in theory will remove the need to have so many nurses and doctors present for the transfer process. ��The device comprises of 8 main components

1. The Rail mount which supports the full weight of the arm and load

2. The mounting hub which connects the mount to the rest of the system

3. One of two linkage pairs

4. The center hub which connects the two linkage pairs

5. The second pair

5. The payload hub which connects the arm to the load

5. The accessory holder which mounts to the Jet Ventilator box and holds the ventilator tubes and other accessories in place

6. And finally the shoulder mount is attached to the accessory holder and rests on the parents shoulder to keep vital equipment nearby while they hold their baby

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System Design

For Internal Use Only. Do not Distribute. Slide 6

Reuven

Locking Joints

Free Joint (no lock)

Solenoids

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Design Usage Procedure

Objective: Minimize Labor Requirements for Active Transfer

For Internal Use Only. Do not Distribute. Slide 7

Mayah

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Risk Reduction Procedure

For Internal Use Only. Do not Distribute. Slide 8

Mayah

Define Components

Determine Failure Modes

Worst Possible Consequence of Failure

List Failure Causes

Define Severity

Probability of occurrence

Control / Reduction Effort

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Locking Joints

For Internal Use Only. Do not Distribute. Slide 9

Reuven

Define Components

Push-Pull Solenoid

15N Pull Force @ 0.75” Stroke

Locking Pin

ANSI 1566 Carbon Steel
Yield Strength 100,000 PSI

Rotational Gear

7075 Aluminum
R0.35” Indents for Locking

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Locking Joints

For Internal Use Only. Do not Distribute. Slide 10

Reuven

Determine Failure Modes

Solenoid Failure

Unintended Locking / Unlocking

Locking Pin Failure

Breakage
Interlocking Failure

Rotational Gear Failure

Damage to indents
Misalignment

User Error

Ultimate Failure Effect: Unexpected movement of linkage

Define Components

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Locking Joints

For Internal Use Only. Do not Distribute. Slide 11

Reuven

Control & Reduction

Redundancy

Two Locking Joints per hub

Material Selection

High-Strength materials for high-stress applications

Usage Direction

Prevent mistakes and errors

Determine Failure Modes

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Parallel Linkages

For Internal Use Only. Do not Distribute. Slide 12

Mike

Structure Components:

7075 Aluminum
M4 screws
0.5" ball-bearings

Durability & Accuracy
Initial Cost & Maintainability

High Risk Areas:

Bearing connection points

Future Risk Tests:

Load capacity (1.5x max)
Fatigue testing

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For Internal Use Only. Do not Distribute. Slide 13

Parissa

50 lbs.

Load Bearing Capacity

Secure Attachment

Material Durability

Ability to be sanitized

Redundancies

Rail Mount

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Rail Mount

Slide 14

Parissa

Side profile of rail attached to Drager Ventilator. Rail will be used to attach KangaMove to ventilator.

Integration

Draeger Equipment
Mounting Hub

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Rail Mount

Design

Requirements

Slide 15

Parissa

Safety Requirements

High Risk Areas

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Pivot

Tapered-Roller Bearings

Steel

Thrust Load Bearing

Static: 3400 Ibs
Dynamic: 550 Ibs
Lubricated to minimize friction

Requirements

Rotate Smoothly
Support Weight of Arm & Equipment

For Internal Use Only. Do not Distribute. Slide 16

Jeffrey

Location of Bearing

Our Pivot System which means the YAW direction of rotation will be using a Tapored-Roller Bearings which is made out of Steel, which will give us a Thrust load Bearing as shown for both static and dynamic values. It will also be lubricated to minimize friction to allow for easy adjustment of the bearing. We intend on using this kind of bearing because of the direction of the load. These load values give us a large factor of safety and will allow us to have a substantial amount of rotations before failure.

When looking at the design we can see the location of the bearing and how we intend on attaching the arm to the mount and bearing.

Our requirements for this component is for it to rotate smoothly and also support the weight of our arm & equipment which is the payload we expect to be connected.

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Pivot

Pros:

Load Capacity (Thrust)
Durable
Fits into Mount

Cons

Price
Complexity
Heavier

For Internal Use Only. Do not Distribute. Slide 17

Jeffrey

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Safety Regulations & Procedures

For Internal Use Only. Do not Distribute. Slide 18

IEC 60601	ISO 13485	510(k)
International Electrotechnical Commission	International Organization for Standardization	Food and Drug Administration - 21 CFR 807 Subpart E
Broad Electrical, Mechanical and EMC (electromagnetic compatibility) safety	QMS (Quality Management Standard) for lifecycle management	Pre-market Requirement for Class I/II devices
Supports compliance with FDA’s General Controls and Special Controls	Supports compliance with FDA QMS Standards	Significant equivalence to approved predicate device safety standards

Mayah

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Remaining Questions

Are there any unexpected situations we should anticipate for the use of the arm?
What is the cleaning & sterilization requirements for accessory devices?
What are the specific tests Sponsor, Nurse, NICU RT would like to see?

For Internal Use Only. Do not Distribute. Slide 19

Jeffrey

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Slide 20

Jeffrey

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Slide 21

Jeffrey

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Slide 22

Jeffrey

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For Internal Use Only. Do not Distribute. Slide 23

Thank You

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Risk Diagram

Slide 24

Jeffrey

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Gantt Chart

For Internal Use Only. Do not Distribute. Slide 25

Jeffrey

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For Internal Use Only. Do not Distribute. Slide 26

Failure Mode	Worst Failure Effect	Severity	Failure Cause(s)	Probability	Mitigation
Joint releases unintentionally	Arm falls and the vent box is torn from the child	High	Power Failure - Electrical	Low	Solenoid is defaulted to locked position
			Mechanical Failure (locking pin breaks) - Mechanical	Low	Re-enforce locking pin, perform extensive force testing
			Joint is misaligned with locking pin - Mechanical	Likely	Springs force locking pin into contact as soon as it is aligned
			User accidentally presses release button – User Error	Likely	Add a toggle switch to disable the controls of the arm
Joint is unable to release	The parent can move in a large degree and the joints will suffer extreme forces	Medium	Solenoid is unable to pull locking pin back due to friction - Mechanical	Somewhat Likely	Introduce bearings above and below the locking pin to allow smooth movement along its axis
Joint is unable to release		Medium	Solenoid does not receive power signal - Electrical	Somewhat Likely	Have feedback to signify if the arm is not receiving power

Risk Analysis – Locking Joint

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For Internal Use Only. Do not Distribute. Slide 27

Risk Analysis – Definitions

Failure Mode – What can go wrong
Failure Cause – Why did it go wrong

List all conceivable causes, however unlikely but foreseeable and describe mitigation efforts

Failure Mode Effect – Worst possible result
Scope

Which components, processes, procedures, etc. are within the scope of this risk analysis
Consider inputs and outputs

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Safety Compliance

IEC 60601:

-DDP (Design Development Plan) Documentation

-Test Plan

-Test Protocol

-Test Report

-Summary Report

ISO 13485:

-Quality Policy and Objectives

-Quality Manual

-Required Procedures and Records

-Additional Necessary Documents*

-Regulatory Documents**

For Internal Use Only. Do not Distribute. Slide 28

*As determined by organization internally

** Any explicitly required documentation detailed by regulatory authorities

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Market Approval

FDA 510(k):

-Description of Device

-Predicate comparison

-Testing Documentation

-Labeling

Basic Requirements:

-Establish Registration with the FDA

-Premarket Notification 510(k) or PMA

-Quality System Regulation (QSR)

-Labeling Requirement

-Medical Device Reporting (MDR)

For Internal Use Only. Do not Distribute. Slide 29

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Project Management for Next Quarter

Solenoid properly engages/ disengages with joint – Week 2
Finish CNC Machining – Week 4
Rail Mount finished – Week 5
Assembly of Joints - Week 6
Linkage functions & can support itself with no weight – Week 7
Demo run with Nurses & NICU RT – Week 8

For Internal Use Only. Do not Distribute. Slide 30

Jeffrey

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Pros:

Conforms with Existing Procedure
Size

Cons:

Existing Products
Failure Possibility
Comfortability

Parissa

Prior Design Idea – Support Vest

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High Risk Areas:

Infant / Parent Comfort
Securing box

Planned Risk Reduction Test:

Material Durability

Parissa

Prior Design Idea – Support Vest

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Prior Design Idea - Ventilation Cable Tension Sensor

Pros:

Prevent excessive tension on baby’s ventilator cable

Cons:

Possibility of failure
Additional device and cabling added to complex ventilator system

Reuven

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Prior Design Idea - Ventilation Cable Tension Sensor

High Risk Area:

Alarm Accuracy

Planned Risk Reduction Test:

Determine Threshold Tension Value Empirically
Sensor Testing

Reuven

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Design Description：

Secure Tube Management
Safe Transfer
Skin-to-skin Care

Pros:

Reduce Manpower Needs
Similar existing structures
Integrated Design

Cons:

Large footprint
Complex Structure
Requires large factor of safety
High initial cost

Mike

Prior Design Idea – Integrated Infant Transfer System

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High Risk Areas:

Infant Overall Safety
Effect on Efficiency
Tube Connection Safety

Planned Risk Reduction Test:

Hardware Testing

Simulated User Operation

Load Capacity Tests

Tube Tension Monitoring

Analytical Prediction

Stress Data Analysis & Safety Assessment

Mike

Prior Design Idea – Integrated Infant Transfer System

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Prior Design - Alarm Box

Pros:

Battery operated
Low Battery indicator
Auditory and visual alert methods

Cons:

Complex ventilator system
Requires batteries

Additional regulatory constraints

Jeffrey

Moving to the next component, the pros that we have is we want to explore the idea of using battery power to minimize the amounts of tubes and cables that pass to and from the infant. In addition, we will be including a low battery indicator to ensure that nurses are warned in case the battery looses charge. In addition, we plan to include both Auditory and visual alerts to have redundant safety measures to warn the nurses that the sensor detects something.�With this new alarm box, it will add a new level of complexity to the overall procedure. Furthermore, as the alarm box requires batteries it will require additional safety regulations to consider.��Feedback:

- Soft shell for box? Sharp corners?�- Tactile Sensor as an option, address it

Draw block diagram to illustrate the process
Identify the threshold values
Identify safety factors
Make sure to clearly say why we need the alarm

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Prior Design - Alarm Box

High Risk Areas:

Loud Noises (45db max)
Alarm Fatigue

Planned Risk Reduction Test:

Response Time
Alarm Testing
Connectivity Testing
Redundancy Testing

Jeffrey

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For Internal Use Only. Do not Distribute. Slide 39

Components being analyzed	Types of failures	Probability	Severity	Failure
Locking Joint	Mechanical	Unlikely	Low	Mode – what
Joint Solenoid	Electrical	Somewhat Likely	Medium	Cause – why
Support Arm	User Error	Likely	High	Effect
Linkage Arm	Physical	Very Probable	Fatal	Mitigation
Rail Mount		Will Happen
Vent Box Holder

Risk Analysis – Categories

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Slide 40

Define Components

Determine Failure Modes

Worst Possible Consequence of Failure

Define Severity

List Failure Causes

Probability of occurrence

Control / Reduction Effort

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Risk Reduction Procedure

For Internal Use Only. Do not Distribute. Slide 41

Parissa

Define Components

Design Components

Locking Joints
Linkages
Rail Mount
Pivot
Support Hub

Design Requirements

Regulatory Compliance
Fundamental Requirements
Safety