Page 417 - Flexible Robotics in Medicine

EndoGoose: a flexible and steerable endoscopic forceps 411
Table 18.3: Design failure mode and effect analysis (DFMEA).

Failure
mode Cause of failure Harm Risk Mitigation
Breakage of Mechanical failure of Ability to steer in that Low Forceps can be withdrawn
guiding the material direction is lost but no harm Likelihood of failure extremely
cables slim
Breakage of Mechanical failure of Forceps will not stay in place Low Forceps can still be withdrawn
gooseneck the material once joystick is released, no Likelihood of failure extremely
harm slim
Breakage of Mechanical failure of Forceps will not be able to Low Design verification shows that
nylon cable material close, no harm the likelihood occurrence is
low
Allergic Nonbiocompatibility Allergy reaction may lead to Low Conduct test as per ASTM
reaction of a prototype death standards
material

Table 18.4: Metrics with units. Each metric was linked to its related
operator needs in Table 18.5.

Metric Units
Duration of biopsy procedure Seconds
Contamination and infection Sterile/nonsterile disposable/reusable
Dimension and operator friendliness Millimeters, yes/no
Shape and strength of forceps Newton
Response time of bending section Seconds

Table 18.5: Needs-metrics mapping matrix with selected important items.

Duration of Dimension and Shape and Response time
biopsy Contamination operator strength of of bending
Metrics needs procedure and infection friendliness forceps section
Actively bendable X X
section
Forceps able to X X
prevent
contamination
Single-handed use X X
Compatible with
various endoscope
models