US 8,984,664 B2 · Helmet blastometer

Abstract

A helmet blastometer for characterizing the direction, speed, magnitude, and duration of a blast event to determine the likelihood of blast-induced traumatic brain injury (biTBI). Time of arrival (TOA) gage sensors are mounted on a rigid outer shell of the helmet each producing a TOA signal in response to a fast rising blast induced positive pressure change above a predetermined threshold. A receiver analyzes the positive pressure changes from the gages to determine direction, speed, and magnitude of a blast. Other TOA gauge sensors can be used to produce a TOA signal in response to a negative pressure change below a predetermined threshold. The positive and negative pressure change TOA signals are used to determine blast duration. A second set of internal contact pressure sensors is connected to an inner liner of the helmet to detect contact pressure on a user's head to determine if biTBI has been sustained.

Claims20

Dependent claims

A helmet blastometer comprising:

a helmet having a rigid outer shell;
a plurality of external sensors connected to the rigid outer shell at various locations thereof, with each external sensor comprising a time-of-arrival (TOA) gage that produces a TOA signal only in response to a blast-induced positive pressure change above a predetermined threshold pressure (“positive-pressure-change TOA signal”);
and
a receiver operably connected to receive the TOA signals from the TOA gages.

1 more element

A helmet blastometer comprising:

a helmet having a rigid outer shell;
a plurality of external sensors connected to the rigid outer shell at various locations thereof, with each external sensor comprising a time-of-arrival (TOA) gage that produces a TOA signal only in response to a blast-induced positive pressure change above a predetermined threshold pressure (“positive-pressure-change TOA signal”), wherein at least one of the external sensors is a dual-gage external sensor further comprising a second TOA gage that produces a TOA signal only in response to a blast-induced negative pressure change below a predetermined threshold pressure (“negative-pressure-change TOA signal”);
and
a receiver operably connected to receive the TOA signals from the TOA gages, wherein the receiver includes a processor adapted to determine blast presence and at least one of blast direction, blast velocity Us, blast overpressure magnitude P, and blast duration, wherein the blast presence, the blast direction, and the blast velocity Us are determined by temporal correlations of the positive-pressure-change TOA signals, the blast overpressure magnitude P is approximated from the blast velocity Us according to the equation
U
s
=
c
o
⁡
(
1
+
6
⁢
⁢
P
7
⁢
⁢
P
o
)
0.5
where co is the ambient sound speed in air and Po is the ambient pressure, and the blast duration is determined from a time interval between the positive-pressure-change TOA signal and the negative-pressure-change TOA signal received from the dual-gage external sensor, and wherein the processor is also adapted to determine that blast induced traumatic brain injury (biTBI) has likely been sustained upon determining that at least one of the blast direction, the blast velocity, the blast overpressure magnitude, and the blast duration has satisfied a corresponding predetermined biTBI threshold.

22 more elements

A helmet blastometer comprising:

a helmet having a rigid outer shell and an inner liner which spaces the rigid outer shell from a user's head;
a plurality of external sensors connected to the rigid outer shell at various locations thereof, with each external sensor comprising a time-of-arrival (TOA) gage that produces a TOA signal only in response to a blast-induced positive pressure change above a predetermined threshold pressure (“positive-pressure-change TOA signal”);
a plurality of internal sensors connected to the inner liner at various locations thereof;
with each internal sensor comprising a contact stress gage which measures contact stress between the inner liner and the user's head and produces a corresponding contact stress signal;
and
a receiver operably connected to receive the TOA signals from the TOA gages and operably connected to receive the contact stress signals from the contact stress gages, wherein the receiver includes a processor adapted to determine blast presence and at least one of blast direction, blast velocity Us, and blast overpressure magnitude P, wherein the blast presence, the blast direction, and the blast velocity Us are determined by temporal correlations of the positive-pressure-change TOA signals, and the blast overpressure magnitude P is approximated from the blast velocity Us according to the equation
U
s
=
c
o
⁡
(
1
+
6
⁢
⁢
P
7
⁢
⁢
P
o
)
0.5
where co is the ambient sound speed in air and Po is the ambient pressure, and adapted to determine that blast induced traumatic brain injury (biTBI) has likely been sustained upon determining that at least one of the blast direction, the blast velocity, the blast overpressure magnitude, and the contact stress has satisfied a corresponding predetermined biTBI threshold.

24 more elements

A helmet blastometer comprising:

a helmet having a rigid outer shell and an inner liner which spaces the rigid outer shell from a user's head;
a plurality of external sensors connected to the rigid outer shell at various locations thereof with each external sensor comprising a time-of-arrival (TOA) gage that produces a TOA signal only in response to a blast-induced positive pressure change above a predetermined threshold pressure (“positive-pressure-change TOA signal”), and at least one of the external sensors is a dual-gage external sensor further comprising a second TOA gage that produces a TOA signal only in response to a blast-induced negative pressure change below a predetermined threshold pressure (“negative-pressure-change TOA signal”);
a plurality of internal sensors connected to the inner liner at various locations thereof with each internal sensor comprising a contact stress gage which measures contact stress between the inner liner and the user's head and produces a corresponding contact stress signal;
and
a receiver operably connected to receive the TOA signals from the TOA gages and the contact stress signals from the contact stress gages, wherein the receiver includes a processor adapted to determine blast presence and at least one of blast direction, blast velocity Us, blast overpressure magnitude P, and blast duration, wherein the blast presence, the blast direction, and the blast velocity Us are determined by temporal correlations of the positive-pressure-change TOA signals, the blast overpressure magnitude P is approximated from the blast velocity Us according to the equation
U
s
=
c
o
⁡
(
1
+
6
⁢
⁢
P
7
⁢
⁢
P
o
)
0.5
where co is the ambient sound speed in air and Po is the ambient pressure, and the blast duration is determined from a time interval between the positive-pressure-change TOA signal and the negative-pressure-change TOA signal received from the dual-gage external sensor, and adapted to determine that blast induced traumatic brain injury (biTBI) has likely been sustained upon determining that at least one of the blast direction, the blast velocity, the blast overpressure magnitude, the blast duration, and the contact stress has satisfied a corresponding predetermined biTBI threshold.

23 more elements

Dependencies are inferred from the claim text.

Helmet blastometer

Life of this patent

Helmet blastometer

Life of this patent

Abstract

Claims20