Baby vital sign monitoring belt
The present invention relates to a defibrillation protected flexible sensor belt ( 1 ) suitable for being worn around an abdominal part of a human body. The belt comprises: electrodes ( 8 ) for contacting a skin of the body; a flex-PCB ( 10 ) carrying wiring ( 16 ) that connects the electrodes for readout, and a barrier ( 20 ) that encapsulates the wiring. The barrier includes: a primary barrier structure ( 21 ) formed by a dielectric carrier substrate of the flex-PCB and a dielectric cover layer that covers the wiring; and a secondary barrier structure that encapsulates the first barrier structure. The secondary barrier structure comprises: a first layer ( 22 - 1 ) comprising a first electrically insulating elastomeric composition ( 22 - 1 c ) that extends at least along a skin-facing side ( 25 ) of the belt, and a second layer ( 22 - 2 ) comprising a second electrically insulating elastomeric composition ( 22 - 2 c ) that extends along a non-skin facing side ( 26 ) of the belt.
1 . A flexible sensor belt suitable for being worn around an abdominal part of a human body, comprising:
an electrode portion having one or more electrodes with a surface for contacting a skin of the body,
a flexible printed circuit board (flex-PCB) carrying wiring that connects the one or more electrodes for readout, and
a barrier that encapsulates the wiring
wherein the barrier includes:
a primary barrier structure formed by a dielectric carrier substrate of the flex-PCB and a dielectric cover layer that covers the wiring opposite the carrier substrate; and
a secondary barrier structure that encapsulates the primary barrier structure, said secondary barrier structure comprising at least:
a first layer comprising a first electrically insulating elastomeric composition and that extends at least along a skin-facing side of the belt, and
a second layer, in addition to the first layer, comprising a second electrically insulating elastomeric composition and that extends along a non-skin facing side of the belt.
2 . The flexible sensor belt according to claim 1 , wherein the belt has a thickness≤5 mm.
3 . The flexible sensor belt according to claim 1 , wherein the first and the second electrically insulating elastomeric composition are silicone based rubber compositions.
4 . The flexible sensor belt according to claim 1 , wherein
the first electrically insulating elastomeric composition is a cured flexible mold rubber based composition having a hardness as defined by a Shore-A hardness below 10, and
wherein the second electrically insulating elastomeric composition is a cured flexible mold rubber based composition having a hardness as defined by a Shore-A hardness in a range of 1 to 20.
5 . The flexible sensor belt according to claim 1 , wherein the first electrically insulating elastomeric composition, at least along portions for contacting with the skin of the body, has a hardness that is lower and a tack that is higher than the second electrically insulating elastomeric composition.
6 . The flexible sensor belt according to claim 1 , wherein the first electrically insulating elastomeric composition has a probe tack energy value ≥than 10 mJ/cm 2 when tested on standard substrate maintaining a constant crosshead speed of 10+/−0.1 mm/s.
7 . The flexible sensor belt according to claim 1 , wherein the first electrically insulating elastomeric composition has a peel adhesion when peeled from a standard substrate within a range of 0.1-2 N/mm as determined by ASTM 3330.
8 . The flexible sensor belt according to claim 1 , wherein the barrier is configured to withstand, without breakdown:
a one second (±10%) application of 5000V DC (±10%); and
a one min (±20%) application of 1000 Vrms (±10%)
in accordance with ANSI/AAMI EC12.
9 . The flexible sensor belt according to claim 1 , wherein the first and the second electrically insulating elastomeric composition are silicone based.
10 . The flexible sensor belt according to claim 1 , wherein the flex-PCB is provided with one or more cutouts that allow a direct contact between the first and the second electrically insulating elastomeric composition.
11 . The flexible sensor belt according to claim 1 , wherein the electrode portion of belt has stretchability in a direction along a length of the belt of 5%-15%, when subjected to a tensile force of 5 Newton in a length direction.
12 . The flexible sensor belt according to claim 1 , wherein a remaining portion of the belt ( 3 ) for extending around the abdominal part, outside the electrode portion, has a stretchability in a direction along a length of the belt of at least 40%, when subjected to a tensile force of 5 Newton in a length direction.
13 . The flexible sensor belt according to claim 1 , wherein the flex-PCB comprises a meander structure.
14 . The flexible sensor belt according to claim 1 , further comprising a non-stick cover layer that extends along an exterior face of the barrier, except portions that are covered by the first electrically insulating elastomeric composition.
15 . The flexible sensor belt according to claim 1 , wherein the belt is connected to a connector that is electrically connected to the one or more electrodes via the wiring, said connector configured for wireless transmitting output data from the electrodes for external signal processing.
16 . A system for monitoring vital signs of a human, comprising the belt according to claim 1 and one or more electronic units configured for processing a signal of the one or more sensors comprised in the belt.