Digital wound detection system
View Patent ↗Methods and devices for a miniature, ultra-low power impact recorder for detecting, quantifying and recording the energy of an explosive blast or ballistic projectile impact. In one embodiment, the impact recorder can included a sensor comprised of an array of electromechanical resonators that is sensitive to the vibrations produced in selected, discrete frequency ranges that approximate the spectral signature characteristics of the shockwave resulting from the ballistic impact event, even after traveling through impacted material or body tissues.
1. A method for detecting and characterizing a ballistic impact event comprising:
providing an impact recorder having a self-powered shock sensor powered by a signal from a resonant response to a ballistic impact event, the signal being proportional to a magnitude of the ballistic impact event, the self-powered shock sensor comprising an array of resonators, each resonator in the array being tuned for resonant response within a different frequency range, each of said different frequency ranges being within a frequency range corresponding to that generated by the ballistic impact event, the impact recorder further configured to transport the signal to a memory device and capture a value of the resonant response;
retrieving the captured resonant response value; and
utilizing the resonant response value to detect and characterize the ballistic impact event.
2. The method of claim 1 , wherein the array of resonators comprises an array of piezoelectric cantilever beams.
3. The method of claim 1 , wherein providing an impact recorder further comprises providing a shock sensor tuned to a range of frequencies generated by the ballistic impact of one of a projectile and an explosive blast.
4. The method of claim 1 , wherein providing an impact recorder further comprises providing at least three impact recorders orientated along three orthogonal axes for measurement of the ballistic impact in three dimensions.
5. The method of claim 4 , wherein providing an impact recorder further comprises mounting the at least three impact recorders on a helmet of a user.
6. The method of claim 4 , wherein providing an impact recorder further comprises mounting the at least three impact recorders on the body of the soldier.
7. The method of claim 1 , wherein providing an impact recorder further comprises providing a shock sensor configured to generate a power spectrum density of vibrations caused by the ballistic impact.
8. The method of claim 1 , wherein providing an impact recorder further comprises providing a memory device selected from the group consisting of a magnetic bubble memory cell, a resistive fusible link, a thin film memory cell and a dielectric breakdown cell.
9. The method of claim 1 , wherein providing an impact recorder further comprises providing a microprocessor configurable for hibernation in a low-power sleep state, wherein the signal generated by the shock sensor provides sufficient power to awaken the microprocessor.
10. The method of claim 9 , wherein providing an impact recorder further comprises providing a self-powered shock sensor configured for low-frequency power scavenging.
11. An impact recorder for measuring the severity of a ballistic impact experienced by a combat soldier comprising:
a self-powered shock sensor powered by a signal from a resonant response to a ballistic impact event, the signal being proportional to a magnitude of the ballistic impact event, the self-powered shock sensor comprising:
a plurality of resonators, each resonator being tuned for resonant response within a different frequency range, each of said different frequency ranges being within a frequency range corresponding to that generated by the ballistic impact event;
an electronic circuit configured to carry the signal away from the shock sensor; and
a memory device configured to capture a maximum value of the signal.
12. The recorder of claim 11 , wherein the plurality of resonators further comprises an array of piezoelectric cantilever beams.
13. The recorder of claim 12 , wherein the array of piezoelectric cantilever beams comprise an ascending length.
14. The recorder of claim 11 , wherein at least one of the plurality of resonators is configured to resonate within the range of frequencies generated by the ballistic impact of a projectile.
15. The recorder of claim 11 , wherein at least one of the plurality of resonators is configured to resonate within the range of frequencies generated by the ballistic impact of an explosive blast.
16. The recorder of claim 11 , wherein the electric signal further comprises a power spectrum density of vibrations caused by the ballistic impact.
17. The recorder of claim 11 , wherein the memory device is selected from the group consisting of a magnetic bubble memory cell, a resistive fusible link, a thin film memory cell and a dielectric breakdown cell.
18. The recorder of claim 11 , wherein the memory device is a microprocessor configurable for hibernation in a low-power sleep state, wherein the self-generated signal provides sufficient power to awaken the microprocessor.
19. The recorder of claim 18 , wherein at least one of the plurality of resonators is configured for low-frequency power scavenging.
20. A recorder for measuring an impact event comprising:
a self-powered shock sensor powered by signals from resonant responses to a ballistic impact event, the signals being proportional to a magnitude of the ballistic impact event within a frequency range of vibrations generated by the impact event, the self-powered shock sensor comprising:
an array of piezoelectric cantilever beams, each beam being tuned for resonant response within a different frequency range, each of said different frequency ranges being within a frequency range corresponding to that generated by the ballistic impact event;
an electronic circuit configured to carry the signals away from the shock sensor; and
a memory device configured to capture responses associated with the different frequency ranges conveyed by the signals to detect and characterize the impact event.
21. A method for measuring an impact event comprising:
providing an impact recorder having a self-powered shock sensor powered by signals from resonant responses to a ballistic impact event, the signals being proportional to a magnitude of the ballistic impact event within a frequency range of vibrations generated by the impact event, the self-powered shock sensor comprising an array of resonators, each resonator being tuned for resonant response within a different frequency range, each of said different frequency ranges being within a frequency range corresponding to that generated by the ballistic impact event;
transporting the signals to respective inputs of one or more memory devices; and
processing the signals to obtain information relating to the responses associated with the different frequency ranges conveyed by the signals.