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Nanosecond Electrical Pulse (nsEP) Pain Inhibition Device

Description:

TECHNOLOGY AREA(S): Bio Medical 

OBJECTIVE: To develop a high voltage nanosecond electrical pulse generator for the use in pain inhibition techniques. 

DESCRIPTION: raumatic injury in the battlefield provides a severe complication both short term and long term for the warfighter. Studies suggest that pain intervention very early on provides preliminary improvements in pain, safety, and complications. A device that can relieve pain after quick attachment by a fellow Airman will enable more rapid stabilization and extraction of injured personnel. In addition, such technology can reduce the amount of drugs carried, handled, or administered. It can also help reduce any complications due to side effects, overdose, or allergic reaction typically seen with drug use. Similar to validated nerve block technology, this treatment at the site of the wound allows the injured to remain conscious and may help to alleviate pain. It has been shown that secondary issues such as phantom limb syndrome and chronic pain occur regardless of the use of whole body analgesics, which block the perception of pain but not the sensory signals that reach the brain. Therefore, the cognitive effects of lasting and persistent pain are still “felt” by the brain. Localized pain treatment has been shown to reduce these secondary complications by blocking the signal from reaching the brain, resulting in fewer secondary complications following severe injury. This proposed technology maintains this advantage while also removing the need for localized administration of pain killers. nsEPs are generally ultra-short electric pulses that have durations typically between 0.1 and 10000 nanoseconds, and amplitude in thousands of volts. Applications using high-powered nsEP range from instrument sterilization to in vivo treatment of superficial melanomas. Schoenbach et al. first applied nsEP to cells using a microscopic parallel plate setup and showed dramatic bioeffects, including nuclear granulation, calcium influx into cytoplasm (reported to be from internal stores), permeabilization of intracellular granules, cell apoptosis, and damage to the nuclear DNA. It is hypothesized that “nanopores” are formed within the plasma membrane, allowing for the influx of ions and water into the cell, but still restricting the influx of larger molecules like propidium iodide. Pakhomov et al. further verified this finding using patch clamp technique to measure the plasma membrane integrity following nsEP exposure. Low-intensity nsEP exposures have also generated action potentials (APs), leading to muscle contractions and neural stimulation. Modeling work suggests that at higher voltages (100 kV/cm at 10 ns or 2 kV/cm at 600 ns) nsEPs can cause the inhibition of APs by forming a conductance block. It is anticipated that a man portable device (less than 5 pounds and less than 10000 cm3 in volume) is feasible because the repetition rate to maintain nerve block is anticipated to be less than 0.1 Hertz, requiring minimal power supply volume and cooling capability. 

PHASE I: In Phase I, a prototype design concept will be developed for use in a laboratory setting. The developed “breadboard” should meet basic requirements for repeated nanosecond electrical pulse generation. Generic requirements for the pain inhibition device are: - Adjustable high voltage: 10-80kV - Pulse width: 900-10000 nanoseconds - Rise time: 10 nanoseconds - Pulse repetition frequency: 0.1Hz to 0.003Hz - Load: 200 ohm - Electrode/tissue interface that will allow delivery of maximum current to tissue with no arcing 

PHASE II: The developed breadboard from Phase I will be implemented into a final design solution, a laboratory-use prototype developed, and optimized output validated. Based on the Phase I design parameters, construct and demonstrate a functional prototype of the device. The technical feasibility of the device should be validated through voltage and current measurements into a biologically relevant load for high voltage delivery (such as an aqueous-electrolyte resistor). Specifically, the prototype should address the general requirements of Phase I, as well as the method for electrical delivery control and attachment to patient. The SBIR company may propose to do joint testing with 711 HPW/RHDR of the final prototype using RHDR’s electrical measurement capabilities.  

PHASE III: Phase III will transition the device, developed in Phase II, into a clinically acceptable prototype for use during en-route care and in a hospital setting, for use both in military and commercial applications. The SBIR company should propose partnership with an organization (commercial, university, or military), with experience at animal and human research, clinical trials, and FDA coordination of medical devices in order to successfully transition the device to medical end users. In addition, the company should explore airworthiness requirements for airevac scenarios. The translation of the technology can also be explored into the commercial sector for chronic pain therapy. The objective system should be suitable to allow man-portable transport to the field by Independent Duty Medical Technicians (IDMTs). It is anticipated that the IDMTs will be in field conditions for a number of days without access to battery-charging power, therefore, the package should be able to maintain a usable charge for several weeks in a storage condition, then operate for up to 24 hours when attached to a patient. It is anticipated that the electrode assembly will be placed on the patient by the IDMT and remain with the patient until they are delivered to a higher echelon of care or airlifted out of theater. The electronics package should be interchangeable so the electrodes can stay on the patient and the electronics (to include the power supply) can be changed out by treatment providers at the higher echelon of care.  

REFERENCES: 

1: Roth CC, Payne JA, Tolstykh GP, Kuipers MA, Thompson GL, Wilmink GJ, Ibey BL, Nanosecond pulsed electric field thresholds for nanopore formation in neural cells, Journal of Biomedical Optics, 2013, 18(3): 035005-1-10

2:  Joshi RP, Mishra A, Song J, Pakhomov A, Schoenbach K. 2008. Simulation Studies of Ultrashort, High-Intensity Electric Pulse Induced Action Potential Block in Whole-Animal Nerves. IEEE Trans Biomed Eng. 55:1391-1398.

3:  Schoenbach, KH, Beebe SJ, Buescher ES. 2001. Intracellular effect of ultrashort electrical pulses. Bioelectromagnetics. 22:440-448.

4:  Pakhomov AG, Kolb JF, White JA, Joshi, RP, Xiao, X, Schoenbach, KH. 2007. Long-lasting plasma membrane permeabilization in mammalian cells by nanosecond pulsed electric field (nsPEF). Bioelectromagnetics. 28:655-663.

5:  Joshi RP, Mishra A, Song J, Pakhomov AG, Schoenbach KH. 2008. Simulation Studies of Ultrashort, High-Intensity Electric Pulse Induced Action Potential Block in Whole-Animal Nerves. Biomedical Engineering, IEEE Transactions on, 55:1391-1398

KEYWORDS: Pulse Generation, Generator, Nanosecond Pulsers, Pulsed Power Applications, High Voltage, Electrical Pulse Generation 

CONTACT(S): 

Dr. Noel Montgomery 

(210) 539-8052 

noel.montgomery.1@us.af.mil 

Dr. Michael Jirjis 

(210) 539-8035 

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