Bill Johnson, Yakima WA
I wish I had your elegant explanation of how fetuses "hear" ultrasound
22 years ago. Our midwife had a new hand held Doppler, and got
frustrated with our son since every time she used it he would turn in
the womb. It was completely obvious to my wife that he "heard" the
ultrasound, since he would be lying peacefully until the midwife touched
her with the Doppler. I told her he "sensed" it but I doubted he could
hear it. "It uses energy," I said, and mumbled something the amniotic
fluid might enhance the effect, but the frequency was above human range.
In spite of my explanation (or because of it) she figured we could get a
dog whistle to call him home when he was old enough to run around.
The midwife said he was the only one of the eight or so babies she was
preparing to birth that reacted that way, a positive aversion to the
monitor. When she asked what I did for a living, she was quite taken
aback. "Don't expect him to follow in your footsteps!"
Never tried the dog whistle.
On Sat, 1 Apr 2006, Kirk Beach wrote:
"As an expert in obstetrics, you know that a fetus will "hear" an
ultrasound examination, not because the fetal ear can hear 3 MHz
ultrasound (they don't "hear" CW Doppler fetal monitors) but because the
radiation force of the pulsed ultrasound bursts, at a 5 KHz PRF for
Doppler or at a 30 Hz frame rate for 2-D B-mode imaging, knocks on the
oval window of the coclea (and probably even on the hair cells in the
coclea) to allow the fetus the "hear" the ultrasound PRF, which is
their hearing range."
CONFIDENTIALITY NOTICE: The information contained in this email, including any attachments, is private, confidential and protected from disclosure. If the reader of this message is not the intended recipient, or an employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any unauthorized review, disclosure or distribution is strictly prohibited. If you have received this communication in error, please notify us immediately by replying to the message and deleting it from your computer. Thank you. Pacific Vascular, Inc.
To unsubscribe or search other topics on UVM Flownet link to: