Apparatus and methods for biomimetic expression of breast milk
An apparatus for biomimetic expression of breast milk can comprise a breast interface having an expandable membrane configured to mimic the geometry of an infant's mouth. Various regions of the expandable membrane may be configured to simulate the structure and/or function of various parts of an infant's mouth. The expandable membrane may comprise one or more of a distal sealing region configured to simulate the lips, a superior region configured to simulate the hard palate, an inferior protruding region configured to simulate the gums, an intermediate curved region configured to simulate the tongue, and one or more internal expansion regions configured to simulate the soft palate and the throat. The expandable membrane may have a varying thickness throughout the one or more various regions to enable movement of the regions similar to the movement of the corresponding regions of an infant's mouth during nursing.
1. An apparatus for biomimetic expression of breast milk from a breast, the apparatus comprising:
a rigid housing; and
an expandable membrane coupled to the housing to form a chamber therebetween, the expandable membrane having a distal opening to receive at least a portion the breast therethrough and a proximal opening opposite the distal opening,
wherein the expandable membrane is operably coupled to an actuatable assembly configured to alternate between an actuation phase and a resting phase during operation,
wherein the expandable membrane comprises an expandable region adjacent the proximal opening, the expandable region configured to expand and move towards the rigid housing during the actuation phase of the actuatable assembly, thereby generating negative pressure at the breast to cause the expression of breast milk from the breast,
wherein the expandable membrane comprises a distal sealing region adjacent the distal opening, the distal sealing region configured to fluidly seal against the breast, and
wherein the expandable membrane comprises at least one movable region disposed between the expandable region and the distal sealing region, the at least one movable region configured to be responsive to a transition from the actuation phase to the resting phase to move towards the breast during the resting phase to compress the breast as the expandable membrane transitions to the rest phase and contracts towards the breast.
2. An apparatus as in claim 1 , wherein a thickness of the expandable membrane varies through different regions of the expandable membrane.
3. An apparatus as in claim 1 , wherein the distal sealing region comprises an inferior portion having a first wall thickness and a superior portion having a second wall thickness greater than the first wall thickness.
4. An apparatus as in claim 3 , wherein the inferior portion of the distal sealing region is configured to deflect downwards during the actuation phase.
5. An apparatus as in claim 1 , wherein the at least one movable region comprises an inferior protruding region proximally adjacent an inferior portion of the distal sealing region and protruding radially inwards towards the breast.
6. An apparatus as in claim 5 , wherein the inferior protruding region is configured to compress against a nipple or an areola of the breast during the resting phase.
7. An apparatus as in claim 5 , wherein the inferior protruding region is configured to fold downwards and away from the breast during the actuation phase to allow breast tissue to be pulled proximally into the expandable membrane.
8. An apparatus as in claim 1 , wherein the at least one movable region comprises an intermediate curved region distally adjacent the expandable region, the intermediate curved region comprising a central portion disposed between flanking portions, the central portion having a greater thickness than the flanking portions, and the flanking portions configured to deflect downwards during the actuation phase and upwards during the resting phase to cause movement of the central portion towards the breast during the resting phase, thereby causing compression of the breast.
9. An apparatus as in claim 1 , wherein the expandable membrane further comprises a superior region disposed between a superior portion of the distal sealing region and the expandable region, the superior region comprising a distal portion having a first thickness and a proximal portion having a thickness that gradually decreases from the first thickness to a thickness of the expandable region.
10. An apparatus as in claim 9 , wherein the distal portion of the superior region is configured to compress against the breast when the at least one movable region moves towards the breast during the resting phase.
11. An apparatus as in claim 10 , wherein the distal portion of the superior region comprises a textured internal surface.
12. An apparatus as in claim 1 , wherein the expandable region is configured to elastically deform during the actuation phase.
13. An apparatus as in claim 1 , wherein the expandable region comprises one or more pleats or curved portions that allow the region to expand radially outwards during the actuation phase.
14. An apparatus as in claim 1 , wherein the expandable region does not directly contact the breast during the expression of breast milk.
15. An apparatus as in claim 1 , wherein the expandable membrane is operably coupled to the actuatable assembly via a tube coupled to the housing and to the actuatable assembly, wherein the tube and the chamber are filled with a driving fluid, and wherein actuation of the actuatable assembly causes movement of the driving fluid into or out of the chamber.
16. An apparatus as in claim 15 , wherein the driving fluid comprises a substantially incompressible fluid.