This password protected page is for the sole use of Nelson Powell and is not accessible to the public.
Nelson:
I've documented some of the OSA-related projects we've talked about here along with various other ideas.
-Roger
Tissue Compression
Spiral Tissue Compression
Tissue compression via a coiled suture.
After insertion the ends are pulled tight, and each tied off and secured
to the surface with a perforated disk.
The main obstacle to this method is that the suture will not
slide within a spiral channel longer than about 180 degrees, and without sliding there can be no compression.
Suture Vortex Tissue Compression
This method uses a group of 3 or 6 parallel sutures that are
inserted straight through the tissue, then attached to perforated disks on each end.
The disks are then rotated to provide the compressing force and secured to
the surface using an additional tab on the disk to prevent further rotation.
A prototype of both the tool and the disks were built, and tests were done
using ballistics gel.
Genioglossus Advancement
GA Distraction with Captive Screw Bracket Actuation
This bracket attaches securely to the typical GA bone fragment using 2 or 3 screws.
The bracket has a screw on each side which is axially fixed to the bracket using a captive nut.
The screws are free to rotate and align with threaded inserts embedded in the mandible.
Turning the screws results in movement of the bone fragment.
A fixture would have to be used during the initial surgery to precisely align the
bone fragment with the threaded inserts.
A prototype of the bracket has been made and attached to a mandible model.
GA with Bracket Deformation Actuation
This design uses a bracket attached to the bone fragment like others, but
it's attached with screws and short spacers so the flanges can slide.
The bracket has 2 weak spots on each side allowing a simple right-angle tool having
a slot to adjust the bend angle. This results in various degrees of advancement.
This design seems promising because of its simplicity, elimination of the need for precise alignment,
vertical intraoral access for adjustment, and forward/backward rigidity.
GA Bracket with Wedge Actuation
With this method, the bracket uses a pair of tiny wedges on each side of
the bone fragment to adjust advancement.
Screws at the top (parallel with the teeth) of each wedge assembly bring the
wedge components together to advance the fragment.
This arrangement has the benefit of easier access through tiny incisions inside
the mouth where the initial incisions were made.
Design and fabrication of the mechanics will be tricky but I believe possible.
GA Bracket with Cam Actuation
This is a variation of the wedge idea but uses a cam on each side of the bracket.
Turning each cam adjusts the bone fragment advancement.
Problems with this design include needing to prevent the forward movement of
the fragment and locking of the cam at various positions - neither appears insurmountable.
This method shares the vertical intraoral access benefits of the wedge design.
GA Bracket with Inflatable Actuation
This design uses a bracket fixed to the bone fragment like other designs listed here
but actuation is done by a tiny inflatable balloon on each side.
This design, while challenging or unworkable, possibly has the benefit of adjustment via hypodermic needle
avoiding incisions altogether.
Mandible Distraction
Intelligent Distraction Actuator
This device uses a tiny permanent magnet gear motor and leadscrew-driven linear actuator mechanics.
The motor is driven and controlled by a pre-programmed microcontroller that fits within the
body of the device.
A short-range wireless data link allows adjustment of the actuator and reading/confirmation of
the actuator's position, available battery power, and possibly sensors indicating stresses or impacts.
Power is supplied by a miniature battery which can be charged inductively through the skin.
Tissue Stiffening Implants
Magnetically Activated Linear Stiffener Implant
This idea uses a bead-like string that is inserted into the tissue (tongue, etc).
The individual beads have hollow channels and the string has a series of rods that slide through the channel.
On each end of the string is an ecapsulated magnetic actuator.
Normally the implant will flex freely, but upon actuation the string becomes stiff.
Actuation is accomplished by a tiny but powerful magnet that moves the string and rods
inside the bead channels locking them together.
Actuation from one side locks the beads, from the otherside unlocks them.
There is quite a bit of work needed to miniaturize the actuation mechanisim.
Active Positional Compensation
Cervical Spine Curvature Actuator
This is an actuator that acts upon the sleeper's neck position.
The actuator, processor and battery pack are embedded in a common
soft collar used for support after neck injuries.
Actuation can be controlled with feedback from the neck curvature sensor (see below)
or the audio snoring analysis system (see below).
Nasal Dilation
Electro-Magnetic Nasal Dilation
This device utilizes a servoed electomagnet to affect the nasal opening which
has a small ferroelectric implant.
Upon activation, the electromagnet energizes pulling the implant and opening the nasal opening
and an optical sensor detects the deformation and servos the electromagnet to the desired force.
Diagnostics
Spinal Curvature Logging
Thin strips of tape-like sensor material are now available that change electrical resistance upon deformation.
The sensor can be affixed to the back of the neck from the hairline down about 10cm in order to detect
the angle of the head.
The resistance of the sensor can be measured and recorded along with other channels during a sleep study.
The data can then be used to correlate neck angle with breathing events.
Accelerometer-Based PSG Sensor
Tiny multi-axis accelerometers are now constructed with silicon wafer processes.
These devices draw very little current, are relatively inexpensive
and are easily interfaced with a microprocessor.
These sensors could be used in place of chest, abdominal and limb sensors
currently used for polysomnography.
The data could be wirelessly transmitted to a nearby receiver eliminating
the need for a wiring harness, adding to patient comfort and likely improving sleep efficiency
which is notoriously poor during studies.
Snore Spectrum Analysis
It's my assertion that the audio spectrum of a typical apneic snore contains
frequencies indicating the mass of vibrating tissue and therefore a clue to its location.
This data could aid treatment selection.
To prove this, patients with known obstructive locations would have their snore audio
digitized and the resulting data would be run through a fast Fourier transform algorithm
to extract the frequency components, deducing the mass of the tissue vibrating, thus providing
evidence of the tissue responsible.
Airflow velocity measurements might also be needed to aid calculations.