poster draft from bioengineering’s capstone design course

Poster Draft from Bioengineering’s Capstone

Design Course

SpiralAT: First Generation Artificial TracheaTheodore John, Insiya Hussain, Nicole Campuzano, and Yoon Kim

Department of Bioengineering, Rice University, Houston, [email protected]

s

Mission Statement

We aim to provide the first artificial trachea unit that is:• Ready for immediate implantation in life-threatened

patients • Performed in a single-step surgical procedure

Motivation for Artificial Trachea

Clinical Significance of Tracheal Replacement• 90% of primary tracheal cancers are malignant• Of the 90,000 new cases/year of cancers in nearby

throat tissues, 25-50% will develop into secondary tracheal cancer

• Other patients suffer from congenital defects and physical trauma

• Currently, there is no standardized solution

Current Approaches Sub-optimal• Tracheal resection: limited for secondary tumors• Radiation: studies vary in conclusions of effectiveness• Case-by-case artificial trachea: multi-staged surgeries,

impractical for patients with urgent needs

Solution: The SpiralAT

• Ready for immediate implantation• Helical geometry provides increased stability and

rigidity• Porous mesh allows for enhanced tissue integration

Design Objectives

Mechanical Testing

3-point bending test

Compression test

Biocompatibility Testing

Future Clinical Studies in Canines• Quantitative analysis of extent of skin flap integration

• Measuring cross-sectional area at the most stenotic point of the trachea

• Qualitative endoscopy• Tissue ingrowth • Inflammation• Granulation tissue formation• Wound dehiscence • Tracheal extrusion/migration

Conclusion

• Need: Readily implantable, tracheal replacement performed in a single-step surgery

• Solution: Standardized artificial trachea unit that comprises a polyethylene helical structure for stability and a polypropylene mesh for good tissue integration

• Preliminary tests show that the SpiralAT allows for flexible motion without any permanent deformation or fracture

References

• Glatz F, Neumeister M, Suchy H, Lyons S, Damikas D, Mowlavi A., A tissue-engineering technique for vascularized laryngotracheal reconstruction, Arch Otolaryngol Head Neck Surg. 2003 Feb;129(2):201-6

• Fujiwara T, Maeda M, Kuwae K, Nakagawa T, Nakao K., Free-prefabricated auricular composite graft: a new method for reconstruction following extended hemilaryngectomy, Br J Plast Surg. 2005 Mar;58(2):153-7

• US Dept of Health and Human Services Cancer Statistics 2002• American Cancer Society 2006

AcknowledgementsWe’re grateful for the support of Dr. Peirong Yu, Dr. Michael

Liebschner, Dr. Maria Oden, Kevin Bowen, Eugene Koay, Cain Project, and Rice University’s Dept. of Bioengineering.

Flexibility in flexion/extension Flexibility in flexion/extension (flex/ext) and lateral bending(flex/ext) and lateral bending

Functional Range of Functional Range of MotionMotion

3.3-3.5 cm diameter3.3-3.5 cm diameter

6 cm length6 cm lengthSpecific SizeSpecific Size

> 90% of tissue > 90% of tissue vascularizedvascularized

Stable and Sufficient Stable and Sufficient VascularizationVascularization

Scar tissue < 10% of total Scar tissue < 10% of total surface areasurface area

BiocompatibilityBiocompatibility

Fig. 2. Simulation of flex/ext using a tennis ball covered crosshead to distribute the force across a wide area of the sample

Fig. 3. Increasing BLANK shows increasing BLANK (crosshead speed=20 mm/min, max extension=10 mm)

Fig. 4. Simulation of flex/ext lateral bending using an angled wedge attached to upper crosshead used to focus compressive force on one side

Fig. 5. Increasing load results in elastic deformation for flex/ext and lateral bending (crosshead speed=20 mm/min, max extension=10 mm)

Fig. 1. The SpiralAT consists of 2 separate components, a polyethylene helical support structure (A) and a polypropylene mesh shell (B)

Deformation (mm)

Load

(N

)

R2 = 0.9911

0

0.4

0.8

1.2

1.6

0 2 4 6 8 10

Deformation (mm)

Load

(N

)

R2 = 0.9911

0

0.4

0.8

1.2

1.6

0 2 4 6 8 10

Fig. 6. Post-operative examination of an artificial trachea in canine throat

A

B



s

Mission Statement













Design Objectives

Mechanical Testing


Compression test





Conclusion




References



















Deformation (mm)

Load

(N

)

R2 = 0.9911

0

0.4

0.8

1.2

1.6

0 2 4 6 8 10

Deformation (mm)

Load

(N

)

R2 = 0.9911

0

0.4

0.8

1.2

1.6

0 2 4 6 8 10


A

B

Nice background, title bar and headings



s

Mission Statement













Design Objectives

Mechanical Testing


Compression test





Conclusion




References



















Deformation (mm)

Load

(N

)

R2 = 0.9911

0

0.4

0.8

1.2

1.6

0 2 4 6 8 10

Deformation (mm)

Load

(N

)

R2 = 0.9911

0

0.4

0.8

1.2

1.6

0 2 4 6 8 10


A

B

Mission statement should be one sentence; needs emphasis.

Increase white space to the left of the text/bullets in this vertical white panel. Bullets and corresponding text should be closer together.

Too much white space between headings and text in each section.



s

Mission Statement













Design Objectives

Mechanical Testing


Compression test





Conclusion




References



















Deformation (mm)

Load

(N

)

R2 = 0.9911

0

0.4

0.8

1.2

1.6

0 2 4 6 8 10

Deformation (mm)

Load

(N

)

R2 = 0.9911

0

0.4

0.8

1.2

1.6

0 2 4 6 8 10


A

B

Punctuate sentences.

Cut “Currently”; emphasize with bold/color: “There is no standardized . . .”

“Limited” how?



s

Mission Statement













Design Objectives

Mechanical Testing


Compression test





Conclusion




References



















Deformation (mm)

Load

(N

)

R2 = 0.9911

0

0.4

0.8

1.2

1.6

0 2 4 6 8 10

Deformation (mm)

Load

(N

)

R2 = 0.9911

0

0.4

0.8

1.2

1.6

0 2 4 6 8 10


A

B

Label image and cut caption

What about the other prototypes?

Use different size or bold font to emphasize the difference between regular text and figure caption.



s

Mission Statement













Design Objectives

Mechanical Testing


Compression test





Conclusion




References



















Deformation (mm)

Load

(N

)

R2 = 0.9911

0

0.4

0.8

1.2

1.6

0 2 4 6 8 10

Deformation (mm)

Load

(N

)

R2 = 0.9911

0

0.4

0.8

1.2

1.6

0 2 4 6 8 10


A

B

Word choice? Dimensions?

Consider placing Design Objectives before your Solution.

Design doesn’t address this issue.



s

Mission Statement













Design Objectives

Mechanical Testing


Compression test





Conclusion




References



















Deformation (mm)

Load

(N

)

R2 = 0.9911

0

0.4

0.8

1.2

1.6

0 2 4 6 8 10

Deformation (mm)

Load

(N

)

R2 = 0.9911

0

0.4

0.8

1.2

1.6

0 2 4 6 8 10


A

B

Use r2; too many sig figs?

Tests and results are buried in captions.

Separate the testing of prototypes.

Multiple tests for multiple prototypes



s

Mission Statement













Design Objectives

Mechanical Testing


Compression test





Conclusion




References



















Deformation (mm)

Load

(N

)

R2 = 0.9911

0

0.4

0.8

1.2

1.6

0 2 4 6 8 10

Deformation (mm)

Load

(N

)

R2 = 0.9911

0

0.4

0.8

1.2

1.6

0 2 4 6 8 10


A

B

Good spacing of bullets here, but use different style for sub-bullets.

Lots of space for something not done.

Avoid jargon.

Caption font & line spacing should be smaller.



s

Mission Statement













Design Objectives

Mechanical Testing


Compression test





Conclusion




References



















Deformation (mm)

Load

(N

)

R2 = 0.9911

0

0.4

0.8

1.2

1.6

0 2 4 6 8 10

Deformation (mm)

Load

(N

)

R2 = 0.9911

0

0.4

0.8

1.2

1.6

0 2 4 6 8 10


A

B

Too many words obscure key point.

Evidence?

Is it like in the body?



s

Mission Statement













Design Objectives

Mechanical Testing


Compression test





Conclusion




References



















Deformation (mm)

Load

(N

)

R2 = 0.9911

0

0.4

0.8

1.2

1.6

0 2 4 6 8 10

Deformation (mm)

Load

(N

)

R2 = 0.9911

0

0.4

0.8

1.2

1.6

0 2 4 6 8 10


A

B

Could use smaller font for Acknowledgments and References.

Bullets are different sizes.

Add Brown Foundation Teaching Grant.

Revised poster . . .



s

Mission Statement













Design Objectives

Mechanical Testing


Compression test





Conclusion




References



















Deformation (mm)

Load

(N

)

R2 = 0.9911

0

0.4

0.8

1.2

1.6

0 2 4 6 8 10

Deformation (mm)

Load

(N

)

R2 = 0.9911

0

0.4

0.8

1.2

1.6

0 2 4 6 8 10


A

B

SpiralAT: First Generation Artificial TracheaTeam T.I.N.Y., Rice University

Theodore John, Insiya Hussain, Nicole Campuzano, and Yoon [email protected]

Mission StatementWe aim to provide the first artificial trachea unit that is ready for immediate implantation through a single-step surgical procedure.

Motivation for SpiralATClinical Significance of Tracheal Replacement

•90% of primary tracheal cancers are malignant.

•Of the 90,000 new cases/year of cancers in nearby throat tissues, 25-50% will develop into secondary tracheal cancer.

•Other patients suffer from congenital defects and physical trauma.

Current Approaches Sub-optimal

•Tracheal resection is limited because reconstruction after resection is not feasible.

•Radiation is not fully reliable because studies show inconsistent outcomes in effectiveness.

•Case-by-case artificial tracheas have been built, but require multi-staged surgeries that are impractical for patients with urgent needs.

There is no standardized solution.

Design ConceptDesign Objectives

Design Components

•Synthetic materials allow immediate use.

•Helical geometry provides stability and flexibility.

•Exterior casing promotes tissue integration.


Mechanical Testing


Compression test

Future WorkBiocompatibility Studies in Canines

•Quantitative analysis of skin flap integration

by measuring cross-sectional area at the most stenotic point.

•Qualitative endoscopy of tissue ingrowth and dehiscence.

Conclusion•Need: Readily implantable, tracheal replacement performed in a single-step

surgery.

•Solution: Standardized artificial trachea unit that comprises a polyethylene double-helical structure for stability and a polypropylene mesh for good tissue integration. The Double Spiral DPT is the most promising.

•Testing: The SpiralAT allows for flexible motion without any permanent

deformation or fracture.

Acknowledgements We’re grateful for the support of Dr. Peirong Yu, Dr. Michael Liebschner, Dr. Maria Oden, Kevin Bowen, Eugene Koay, Cain Project, Rice University’s Department of Bioengineering, and the Brown Foundation Teaching Grant.

References•Glatz F, Neumeister M, Suchy H, Lyons S,

Damikas D, Mowlavi A., A tissue-engineering technique for vascularized laryngotracheal reconstruction, Arch Otolaryngol Head Neck Surg. 2003 Feb;129(2):201-6

•Fujiwara T, Maeda M, Kuwae K, Nakagawa T, Nakao K., Free-prefabricated auricular composite graft: a new method for reconstruction following extended hemilaryngectomy, Br J Plast Surg. 2005 Mar;58(2):153-7

•US Dept of Health and Human Services Cancer Statistics 2002

•American Cancer Society 2006

DimensionsDimensions 3.3-3.5 cm diameter3.3-3.5 cm diameter6 cm length6 cm length

Functional Range Functional Range of Motionof Motion

Flexibility in Flexibility in flexion/extension flexion/extension

(flex/ext) and lateral (flex/ext) and lateral bendingbending

BiocompatibilityBiocompatibility Scar tissue < 10% of total Scar tissue < 10% of total surface areasurface area

Stable and Stable and Sufficient Sufficient

VascularizationVascularization



Fig. 3. Single Spiral Rice was the stiffest, followed by Double Spiral DPT and Single Spiral DPT. Adding an additional helix to the Single Spiral DPT increased stiffness. (crosshead speed=20 mm/min, max extension=10 mm)


Fig. 5. Increasing load resulted in elastic deformation. Double Spiral DPT was stiffer than Single Spiral DPT. (crosshead speed=20 mm/min, max extension=10 mm)

Fig. 1. The three versions of the SpiralAT have different structures and are made of different materials. Each version consists of 2 components, a helical support structure and a shell.


0

0.2

0.4

0.6

0.8

1

1.2

1.4

0 0.5 1 1.5 2 2.5 3

Load

(N

)

Deformation (mm)

Single Spiral Ricek = 7.3 N/mm

Single Spiral DPTk = 0.011 N/mm

Double Spiral DPTk = 0.16 N/mm

0

0.5

1

1.5

2

2.5

3

3.5

4

0 0.5 1 1.5 2 2.5 3




Load

(N

)

Deformation (mm)

A) Single Spiral Rice B) Single Spiral DPT C) Double Spiral DPT

polypropylenemesh

polyethylene

polypropylenemesh

polyethylenepolyethylene

polyethylene



s

Mission Statement













Design Objectives

Mechanical Testing


Compression test





Conclusion




References



















Deformation (mm)

Load

(N

)

R2 = 0.9911

0

0.4

0.8

1.2

1.6

0 2 4 6 8 10

Deformation (mm)

Load

(N

)

R2 = 0.9911

0

0.4

0.8

1.2

1.6

0 2 4 6 8 10


A

B

SpiralAT: First Generation Artificial TracheaTeam T.I.N.Y., Rice University

Theodore John, Insiya Hussain, Nicole Campuzano, and Yoon [email protected]

Mission StatementWe aim to provide the first artificial trachea unit that is ready for immediate implantation through a single-step surgical procedure.

Motivation for SpiralATClinical Significance of Tracheal Replacement

•90% of primary tracheal cancers are malignant.

•Of the 90,000 new cases/year of cancers in nearby throat tissues, 25-50% will develop into secondary tracheal cancer.

•Other patients suffer from congenital defects and physical trauma.

Current Approaches Sub-optimal

•Tracheal resection is limited because reconstruction after resection is not feasible.

•Radiation is not fully reliable because studies show inconsistent outcomes in effectiveness.

•Case-by-case artificial tracheas have been built, but require multi-staged surgeries that are impractical for patients with urgent needs.

There is no standardized solution.

Design ConceptDesign Objectives

Design Components

•Synthetic materials allow immediate use.

•Helical geometry provides stability and flexibility.

•Exterior casing promotes tissue integration.


Mechanical Testing


Compression test

Future WorkBiocompatibility Studies in Canines

•Quantitative analysis of skin flap integration

by measuring cross-sectional area at the most stenotic point.

•Qualitative endoscopy of tissue ingrowth and dehiscence.

Conclusion•Need: Readily implantable, tracheal replacement performed in a single-step

surgery.

•Solution: Standardized artificial trachea unit that comprises a polyethylene double-helical structure for stability and a polypropylene mesh for good tissue integration. The Double Spiral DPT is the most promising.

•Testing: The SpiralAT allows for flexible motion without any permanent

deformation or fracture.

Acknowledgements We’re grateful for the support of Dr. Peirong Yu, Dr. Michael Liebschner, Dr. Maria Oden, Kevin Bowen, Eugene Koay, Cain Project, Rice University’s Department of Bioengineering, and the Brown Foundation Teaching Grant.

References•Glatz F, Neumeister M, Suchy H, Lyons S,

Damikas D, Mowlavi A., A tissue-engineering technique for vascularized laryngotracheal reconstruction, Arch Otolaryngol Head Neck Surg. 2003 Feb;129(2):201-6

•Fujiwara T, Maeda M, Kuwae K, Nakagawa T, Nakao K., Free-prefabricated auricular composite graft: a new method for reconstruction following extended hemilaryngectomy, Br J Plast Surg. 2005 Mar;58(2):153-7

•US Dept of Health and Human Services Cancer Statistics 2002

•American Cancer Society 2006

DimensionsDimensions 3.3-3.5 cm diameter3.3-3.5 cm diameter6 cm length6 cm length

Functional Range Functional Range of Motionof Motion

Flexibility in Flexibility in flexion/extension flexion/extension

(flex/ext) and lateral (flex/ext) and lateral bendingbending

BiocompatibilityBiocompatibility Scar tissue < 10% of total Scar tissue < 10% of total surface areasurface area

Stable and Stable and Sufficient Sufficient

VascularizationVascularization



Fig. 3. Single Spiral Rice was the stiffest, followed by Double Spiral DPT and Single Spiral DPT. Adding an additional helix to the Single Spiral DPT increased stiffness. (crosshead speed=20 mm/min, max extension=10 mm)


Fig. 5. Increasing load resulted in elastic deformation. Double Spiral DPT was stiffer than Single Spiral DPT. (crosshead speed=20 mm/min, max extension=10 mm)

Fig. 1. The three versions of the SpiralAT have different structures and are made of different materials. Each version consists of 2 components, a helical support structure and a shell.


0

0.2

0.4

0.6

0.8

1

1.2

1.4

0 0.5 1 1.5 2 2.5 3

Load

(N

)

Deformation (mm)




0

0.5

1

1.5

2

2.5

3

3.5

4

0 0.5 1 1.5 2 2.5 3




Load

(N

)

Deformation (mm)

A) Single Spiral Rice B) Single Spiral DPT C) Double Spiral DPT

polypropylenemesh

polyethylene

polypropylenemesh

polyethylenepolyethylene

polyethylene

Nice job formulating a mission statement from the original text bullets. Bold text treatment works well. Definition of the problem and affected population is effective. Using red text calls attention to need for standardization, which is one of your primary design goals.

Switching the order of the sections devoted to Design Concept and Solution provides a more logical sequence.

Great juxtaposition of the images and graphs in Mechanical Testing. However, presenting the results as captions under the graphs diminishes their prominence and makes it harder to determine whether your design achieved what you set out to do.

poster draft from bioengineering’s capstone design course

Documents

case artificial trachea

primary tracheal cancers

blank crosshead speed

upper crosshead

tissueengineering technique

polyethylene helical

support of

max extension