The present invention generally relates to fluid handling devices, their uses and operation. More particularly, this invention relates to a fluid handling device for treating a person exposed to biological and chemical agents.
The threat of biological and chemical (biochem) attack from terrorists and rogue states has increased in recent years. Biochem threats particularly put military personnel, law enforcement, emergency response, first responders, and postal workers at risk. While not all biochem agents have antidotes, a significant percentage does. For example, antidotes and treatments exist for sarin, VX, tabun, soman, cyanide, lewisite (β-chlorovinyldichloroarsine), anthrax, brucellosis, bubonic plague, Q fever, and botulism.
Biochemical and chemical compounds can be detected through the use of absorption. For example, film materials capable of selectively absorbing certain compounds find use in humidity, pH, glucose, bacteria, blood, cellular, pollution, poisons, gas and biotoxin sensors and detectors. However, many biochem agents that might be used in an attack require immediate treatment to save the victim's life, with the medical response time making the difference between complete recovery and a permanent handicap or death. Making treatment available in the field and in time to be effectively used is desirable but difficult. Treatment on a remote battlefield, especially when fast-acting chemical agents are involved, can be particularly difficult since many affected personnel may be incapacitated. Commercial or military products or systems do not exist that can provide immediate and effective defense against an actual biochem attack.
In view of the above, it would be desirable if a portable rapid-response device were available as a first defense for individuals against chemical and biological terrorist attacks. Such a device would preferably be capable of detecting the type and amount of biochem agent. Such a device would also be preferably capable of selecting one or more appropriate antidotes, and precisely delivering appropriate amounts and concentrations of antidote(s) to the victim. Finally, it would be advantageous if the number of separate components required to perform these functions could be minimized while maintaining or improving the precision by which these functions are performed.
The present invention provides a device capable of delivering precise amounts of one or more antidotes to treat a victim exposed to biological and chemical agents (biochem agents), and also preferably sensing the presence of biochem agents.
According to a first aspect of the invention, the delivery device includes a plurality of reservoirs containing antidotes, a manifold to which the reservoirs are fluidically and removably coupled, an outlet on the manifold, means for selectively releasing at least one of the antidotes from the reservoirs into the manifold, means for sensing flow of the at least one released antidote, and means for stopping flow of the at least one released antidote in response to specified amounts of the at least one released antidote having passed through the flow sensing means.
According to preferred aspect of the invention, the delivery device is preferably used in combination with a device capable of detecting biochem agents. Preferred detecting devices include a freestanding tube portion comprising an internal passage containing a substance selective to a chemical or biological agent so that matter accumulates within the freestanding tube portion when a fluid drawn through the tube portion contains the agent. When vibrated at resonance, the resonant frequency of the tube portion is indicative of the accumulation of matter and thereby the presence of the agent to which the substance is selective. The delivery device then preferably delivers precise amounts of one or more appropriate antidotes to treat the victim in response to the identified biochem agents.
In view of the above, a method performed by the detecting device involves detecting a chemical or biological agent by flowing a fluidic sample through a freestanding tube portion having an internal passage containing a substance selective to a chemical or biological agent so that matter accumulates within the freestanding tube portion, vibrating the tube portion at a resonant frequency thereof that varies with the combined density of the freestanding tube portion and contents of the internal passage, sensing movement of the freestanding tube portion to produce an output signal based on the resonant frequency of the freestanding tube portion and indicative of accumulation of the reaction product, and identifying the agent in the fluidic sample based on the accumulation of the reaction product in the freestanding tube portion.
In a preferred embodiment of the invention, the flow sensing means and the detecting device makes use of a micromachined resonating tube of a type disclosed in U.S. Pat. No. 6,477,901 to Tadigadapa et al. According to Tadigadapa et al., a resonating tube is operated on the basis of the Coriolis effect to sense mass flow and density of a flowing fluid. In the present invention, a resonating tube of the detecting device is adapted to sense a change in the mass of the tube as a result of the matter that accumulates as a result of the presence of a chemical or biological agent drawn through the tube.
The delivery device and the detection device are capable of being miniaturized and combined in a sufficiently small package to permit carrying by a person. As such, the devices are capable of being essential components of a portable rapid-response unit suitable for use as the first defense for individuals against chemical and biological attack. When used together, the detecting and delivery devices are capable of detecting the type and amount of biochem agent present, and then selecting and precisely delivering appropriate amounts and concentrations of the appropriate antidote(s) to the victim.
Other objects and advantages of this invention will be better appreciated from the following detailed description.
With reference to
A flow sensor 30 in accordance with Tadigadapa et al. and suitable for use in or as the flow sensors 18 and 58 is represented in
The device 10 depicted in
As discussed above, the sensor 18 preferably employs one or more micromachined resonating tubes 32 of the type disclosed in Tadigadapa et al. As used herein, micromachining is a technique for forming very small elements by bulk etching a substrate (e.g., a silicon wafer), or by surface thin-film etching, the latter of which generally involves depositing a thin film (e.g., polysilicon or metal) on a sacrificial layer (e.g., oxide layer) on a substrate surface and then selectively removing portions of the sacrificial layer to free the deposited thin film. Accordingly, suitable materials for the tube 32 include glass (e.g., quartz and Pyrex), ceramic, metal or a semiconductor, including micromachined silicon, germanium, Si/Ge and GaAs.
The freestanding tube portion 34 is preferably driven at resonance, with the resonant frequency being determined in part by its mechanical design (shape, size, construction and materials). Suitable frequencies are in the range of 1 kHz to over 100 kHz, depending on the particular fluid being analyzed. Under most circumstances, frequencies above 10 kHz, including ultrasonic frequencies (those in excess of 20 kHz), will be preferred. The amplitude of vibration is preferably adjusted through means used to vibrate the tube portion 34. For this purpose,
In Tadigadapa et al., monitoring the frequency of vibration of the tube portion 34 while a fluid flows through the passage 38 enables the density and mass flow rate of the fluid to be measured. As fluid flows through the tube portion 34 while the tube portion 34 is vibrated at resonance, the tube portion 34 twists under the influence of the Coriolis effect. As explained in Tadigadapa et al., the degree to which the tube portion 34 twists (deflects) when vibrated can be correlated to the mass flow rate of the fluid flowing through the tube portion 34 on the basis of the change in the amplitude of a secondary resonant vibration mode. The density of the fluid is proportional to the natural frequency of the fluid-filled vibrating tube portion 34, such that controlling the vibration of the tube portion 34 to maintain a frequency at or near its resonant frequency will result in the vibration frequency changing if the density of the fluid flowing through the tube portion 34 changes.
In contrast to Tadigadapa et al., the detecting device 10 of
The detecting device 10 has application for detecting the presence of a wide variety of biochemical agents, including chemical warfare agents (mustard gas, cyanide, lewisite, nerve agents, etc.) and biological warfare agents (anthrax, botulism, Brucellosis, plague, Q-fever, etc.). The device 10 can also be employed to detect a variety of other potentially harmful agents, including a variety of bacteria and viruses, dust, soot, organic solvents, drugs, explosive elements, poisons, gases, biotoxins, tainted food, water and air pollution, as well as the presence and/or properties of other chemicals, compounds, and particles of potential interest, such as humidity, pH, glucose, blood and its components, antibodies, cells, enzymes, DNA, proteins, white blood cells, urine and its components, etc. If bacteria detection is desired, the device 10 may require the capability of accumulating and incubating enough cells in the tube 32 for detection. However, since the tube 32 can be fabricated to have a volume of only several nanoliters, it offers the advantage of being able to detect the presence of a bacteria with only a few cells.
Liquid and gaseous deposition techniques can be employed to deposit the film 48, such as by injecting the absorbent or chemically/biologically reactive material into the tube 32 and allowing the material to dry to form the accumulation film 48. The performance of the tube 32 formed by silicon micromachining can be enhanced with several fabrication and design techniques. For example, single or multiple layers can be deposited or formed on the inner surfaces of the tube passage 38 to provide a surface that is more chemically reactive than the material of which the tube 32 is formed, for example, silicon or silicon oxide. For example, a metal such as gold can be deposited and then coated with a film 48 formed by a layer of thiolated single-stranded DNA to detect complementary DNA strands. Furthermore, platinum has been shown to attract proteins. Metal suicides can be deposited to improve adhesion of platinum and other reactive metals to a silicon tube 32. Furthermore, one or more polymer layers can be applied before application of a reaction-promoting layer (if present) and the film 48 to promote adhesion of these layers to tube surfaces formed of silicon, silicon oxide, silicon nitride, metal, metal silicide, etc.
The sensitivity of the tube portion 34 to mass change generally increases as the thickness of the film 48 increases relative to the tube wall thickness. Therefore, a relatively thick film 48 and/or relatively thin tube walls are generally desirable. For the latter, the tube 32 can be isotropically thinned with a plasma or wet etch after release of the tube portion 34 during the fabrication process. Nano-technology can also be used for the fabrication of the tube 32 to further increase the sensitivity of the sensor 30.
Since the densities of materials vary with temperature, temperature control is often used to manufacture highly accurate density meters of the prior art, such as thermoelectrically-controlled resonant temperature systems. Because the densities of the tube material, coatings, and analyzed fluids are all subject to change with temperature, the controller 24 may include a temperature control element (not shown) to sense the temperature of the flow sensor 18 and thereby achieve higher accuracy of chemical and biological detection with the device 10. Temperature control can also be used to improve the performance and reduce the damage to biologic compounds. As represented in
As noted above, the sensor 18 can comprise arrays of the flow sensor 30 depicted in
Because of the miniaturized sensor 18, the detecting device 10 can be small, portable and relatively inexpensive, especially when fabricated by micromachining technology to yield what is known as a microelectromechanical system (MEMS). It is foreseeable that the cost of the device 10 can be sufficiently low to render the device 10 disposable. Alternatively, the sensor 18 can be recycled after the film 48 becomes saturated. For example, heat and/or an aggressive detergent or solvent could be flushed through the tube 32 to strip the inner walls of the film 48 and the matter that has accumulated within the tube 32 as a result of absorption and/or reaction with a biochem agent. After cleaning, the inner walls of the tube 32 can be recoated if needed or desired. In view of the above, device size, batch fabrication and recycling can all contribute to reducing the cost of sensing biochem agents with the device 10.
In an investigation, water was injected into a flow sensor of the type represented in
As previously noted, the delivery device 50 represented in
The device 50 is represented in
As discussed above, the sensor 18 preferably employs one or more micromachined resonating tubes 32 of the type disclosed in Tadigadapa et al. Resonating tube flow sensors of the type disclosed by Tadigadapa et al. are preferred in view of their very small size and ability to precisely measure extremely small amounts of fluids, in contrast to prior art Coriolis-type flow sensors. For example, if the flow sensor 58 of
The reservoir 52 schematically depicted in
While capable of being configured to have any number of cartridges 72, the manifold system 70 depicted in
Delivery of one or more antidotes can be initiated with the controller 64 either through manual input by the user, a radio signal from a remote central location (e.g., the control system 29 of
In addition to the above, the device 50 can be configured to offer other advantages and functions. For example, the ability to measure antidote density can be used to prevent deliver of the wrong antidote or those that are spoiled or contain air bubbles or inclusions. Other functionalities that can be combined with the device 50 include indicating the location of the individual (e.g., through GPS (global positioning system)), broadcasting an alert signal to a remote center or others equipped with similar delivery devices 50 if delivery of an antidote is commenced in response to an attack, monitoring of the individual's biological functions (e.g., heart beat), sending such biological information to a remote center or another individual, etc. Along with the device 50 (including its valve 54, pump 56, sensor 58, and injection device), such additional components can be fabricated by micromachining to yield a fully integrated system that is small, low-power, rugged and biocompatible at high production volumes.
In use, after being notified of the presence of a biochem agent (such as by detection with the detecting device 10), the user can place a needle connected to the device 50 in his or her body and then activate the device 50 to allow the device 50 to deliver the appropriate antidote combination and dosage based on the type and concentration of agent sensed. Alternatively, in high risk situations such as a battlefield or suspected contaminated area, a needle or catheter can be pre-inserted so that the device 50 can inject the appropriate antidote combination and dosage without any (or minimal) direct input or action from the user. In one particular example, a remote central detection system (e.g., making use of the detecting device 10) can be linked through a wireless radio network with one or more of the delivery devices 50. When an alert from the central detection system is received, each device 50 automatically selects the appropriate antidote(s) and delivers the antidote(s) at the appropriate dose and delivery timing to the individual wearing the device 50. In another example, each device 50 has a keypad (not shown) to interface with the controller 64. When instructed that exposure to a chemical or biological agent has occurred (e.g., verbally, through a remote central detection system, with the detecting device 10, etc.), the user can punch in the appropriate code to cause the device 50 to select and deliver the correct antidote. In a third example, the detecting device 10 and the delivery device 50 are contained in a single portable unit, so that the unit contains all of the components necessary to sense and automatically respond to a chemical or biological threat.
In view of the above, the biochem detecting device 10 and antidote delivery device 50 can be combined into a single unit as a first defense for individuals against a chemical and/or biological attack. In combination, the detecting device 10 and delivery device 50 provide for the automatic detection of the type and amount of biochem agent present, selection of an appropriate antidote combination from multiple reservoirs, preparation and mixing of the appropriate antidotes at the correct concentration, and delivery of such antidote(s) with great accuracy. As such, the invention provides a small, portable, rapid-response bio-protector that can be carried as standard equipment by a soldier or other at-risk personnel for rapid treatment during an attack without the intervention of a medical professional. If the treatment is carried out automatically, the invention has the further advantage of being capable of precise dose control and repeated, timed injections as may be necessary.
While the invention has been described in terms of certain embodiments, it is apparent that other forms could be adopted by one skilled in the art. Therefore, the scope of the invention is to be limited only by the following claims.
This is a division patent application of co-pending U.S. patent application Ser. No. 10/709,782, filed May 27, 2004, which claims the benefit of U.S. Provisional Application No. 60/473,383, filed May 27, 2003. This patent application is also a continuation-in-part patent application of co-pending U.S. patent application Ser. No. 10/784,614, filed Feb. 23, 2004, which claims the benefit of U.S. Provisional Application No. 60/449,099, filed Feb. 24, 2003. The contents of these prior applications are incorporated herein by reference.
Number | Date | Country | |
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60473383 | May 2003 | US | |
60449099 | Feb 2003 | US |
Number | Date | Country | |
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Parent | 10709782 | May 2004 | US |
Child | 12031839 | US |
Number | Date | Country | |
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Parent | 10784614 | Feb 2004 | US |
Child | 10709782 | US |