BME 273 Fetal Stabilizer for Intrauterine Surgery

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BME 273Fetal Stabilizer for Intrauterine Surgery

• Michael Dinh
• Advisor Dr. Joseph Bruner

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Spina Bifida

• One of the most common debilitating neural tube
  defect
• Incomplete closure in the spinal column usually
  in the lower section during initial pregnancy.
• Spina Bifida affects approximately 1 out of every
  1,000 newborns in the U.S

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Degree of Spina Bifida

• Spina Bifida Occulta
• Spina bifida occulta is a small gap in one or
  more of the vertebrae. This is the mildest form
  of spina bifida as there is no apparent damage to
  the spinal cord.
• Meningocele
• Meninge (protective layer covering the spinal
  cord) protrudes through the gap in the spinal
  column in a form of a sac. The spinal cord itself
  remains intact and repairs can be made with
  little or no damage. Least common occuring form.
• Mylemeningocele
• Most severe form. This term is generally used
  interchangeably with spina bifida. Spinal cord
  itself protrudes through the gap in the spinal
  column.

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Spina Bifida Manifesta

• Protrusion of spinal cord membrane, spinal cord,
  and nerve roots
• Spinal cord exposure result in progressive damage
• Most often found in the lumbo-sacral region

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Adverse Affect

• Hydrocephalus
• Accumulation of spinal fluid in brain is common
  among infants with spina bifida
• Permanent weakness or paralysis in lower
  extremity below defect
• Loss of bowel and bladder control due to the
  nerve damage

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Vanderbilt University

• 165 cases of spina bifida repair
• Age range of infants 19-30 weeks
• Mean operating time is about 87 min
• Ranges from 62-131 min

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Design Objective

• Design a fetal stabilizer to assist in surgery
• Hold fetus steady while providing an opening for
  operation

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Approach

• Observe open repair of spina bifida
• Collect fetal biometrical data
• Look at similar device in handling fetus
• Simpson Forceps Used in delivery

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Fetal Data

• 19 week old fetus
• 6 inches head to end
• Weight about 8.5 ounces
• Abdominal Circumference about 133 mm
• Width about 60 mm

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Device Design
Top View
Front View
Side View
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Device Specification

• Overall Length 20 cm
• Depth of Paddle Arm 6 cm
• Width of Paddle Arm 4 cm
• Width of device 7.5 cm
• Space b/w Arm Center 6 cm

• Space b/w Arm bottom 5 cm
• Width of opening 5 cm
• Length of opening 7 cm
• Side handle about 45 mm in length

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Conclusion

• Design stabilizes fetus using forces present
• Contracting uterine wall force fetal outward
  force
• Facilitate in operation
• No need for retaining hooks
• Simple in use
• Two piece device
• Varying degree of adjustability for variation in
  fetal size