1. Field of the Invention
This invention relates generally to a syringe-like device that is used to collect samples for analysis. More specifically, the present invention provides a modified syringe-like device that enables single-handed operation when obtaining samples for analysis, and enables electronic chain of custody of the samples being gathered.
2. Description of Related Art
When describing relevant art, it is important to consider that the present invention is capable of securing samples of a variety of different substances. These substances include chemicals in liquid or gas form, and thus Solid Phase Microextraction (SPME) is one field in which the present invention finds application. However, while SPME is typically associated with the extraction of chemicals from liquids and vapors, the present invention can also obtain samples from solids and suspensions of solids.
SPME is known to those skilled in the art as a technique for sampling and concentrating chemical compounds for analysis by chromatography or other methods. Typically, a fiber is used to extract analytes from a sample and deliver them for analysis. The fiber is typically made of a fused silica or metal fiber coated with a polymer or an absorbent that is used to capture and concentrate the analytes by partition or adsorption. The fiber is moved to a sample introduction port of a chromatograph or spectrometer for desorption or extraction for analysis. The fiber used for SPME is typically held in a syringe-like device for convenience. The fiber is easily protected and transferred within the walls of a protective sheath that extends outwardly from the syringe-like device.
Before proceeding with the description of SPME techniques, it is noted that the present invention is using a syringe-like device for sampling, concentration, transporting and injecting samples. While the syringe-like device does not store a liquid within its housing like an actual syringe, the housing of the present invention is constructed to appear like a syringe with a handle, plunger, and a needle-like protrusion that is actually a sheath for the fiber described above. Accordingly, the term “syringe” used in this document and the claims is the syringe-like device to be more fully described hereinafter, and should not be mistaken for an actual syringe.
One of the drawbacks of existing syringes used for SPME is that two hands are typically needed to operate it. For example, a first hand grips the shaft of the syringe while the second hand extracts a plunger to move the fiber into the syringe after a sample has been taken. Thus, the process of obtaining a sample requires two hands. Accordingly, it would be an advantage over the state of the art in SPME syringes to provide a syringe that can be operated with only one hand, leaving the second hand free for other tasks.
Understandably, SPME is not the only application of the present invention that must be considered. It is clearly another aspect of the present invention to be able to use the syringe to also obtain samples from solids and solids in suspensions. For example, solids can be collected on filaments, as opposed to fibers used to collect samples from liquids and gases. The filaments of the present invention are designed with cavities, apertures or other similar features that enable solids to be collected on or within the filament. The present invention also provides a means for collecting solids in suspensions, as will be disclosed.
Samples also need to be carefully tracked from a point of origin, through transport, to final analysis. It would be another advantage over the state of the art to provide the syringe described above having a fiber or filament, and also including means for electronically tracking a chain of custody of samples.
The present invention is a syringe-like device (hereinafter “syringe”) that is operable by a single hand, wherein the syringe includes a plunger for ejecting and then retracting a fiber or filament used for the collection of solids, solids in suspensions and liquids, wherein the syringe includes a microchip embedded in the syringe housing, and wherein the microchip enables electronic chain of custody tracking of a sample from a point of origin through final analysis.
These and other objects, features, advantages and alternative aspects of the present invention will become apparent to those skilled in the art from a consideration of the following detailed description taken in combination with the accompanying drawings.
Reference will now be made to the drawings in which the various elements of the present invention will be given numerical designations and in which the invention will be discussed so as to enable one skilled in the art to make and use the invention. It is to be understood that the following description is only exemplary of the principles of the present invention, and should not be viewed as narrowing the claims which follow.
Operation of the syringe 10 of the first embodiment using only one hand is relatively straightforward. In a first embodiment, a user grasps the handle 12 with all of the fingers of a hand, leaving the thumb disposed over the thumb actuator 14. Alternatively, the user can grasp the handle 12 between an index finger and a middle finger of one hand. The thumb is then placed on top of the thumb actuator 14 such that it is ready for operation in either embodiment.
The user is free to perform other tasks with the hand that is not holding the syringe 10. These tasks include such things as securing a sample container while the sample is being obtained, preparing analysis equipment for sample introduction, and holding another device. Thus, it is immediately apparent that the user is free to do any other task with the free hand, and will typically be free to perform a task that would otherwise need to be performed by another person. Thus, not only does the present invention enable a user to perform more than one task while taking a sample, but also enables samples to be taken in situations where only a single person is present to perform the task.
It is noted for clarity that hereinafter, the term “sample” refers to liquids, solids, and solids in suspensions of any substance that can be sampled using the fiber of the present invention.
A more detailed description of the operation of the syringe 10 is herein described for the first embodiment. The syringe 10 of the present invention includes a camming system in order to lock the fiber 22 into an extended position when actuated a first time, and unlock and retract the fiber when actuated a second time. The spring 20 is required to make the camming system function as indicated above.
An important insight into the invention is that the spring 20 that is used in this first embodiment may be replaced by any suitable spring-like device that provides the needed tension for the cam mechanism 16 to function. Similarly, as the spring 20 and cam mechanism 16 function as a system to enable the fiber 22 to be ejected from and retracted into the protective sheath 28, it is an aspect of the present invention that this system can be replaced by any equivalent means for providing this function of fiber ejection and retraction.
Continuing with the first embodiment, when the syringe 10 is ready for use, the fiber 22 is loaded into the handle 12 and secured via the fiber clamp 32. For example, the fiber clamp 32 can be a small nut. The fiber clamp 32, along with the seals, prevents any chemicals from moving into the handle 12. The fiber clamp 32 also makes it possible to remove and replace the fiber 22 after it has been used to secure a sample. However, it is envisioned that the syringe 10 will be inexpensive enough such that it can be a disposable item. Nevertheless, it is envisioned that the fiber 22 may be replaced and the syringe 10 reused if desired.
When the user is ready to take a sample using the syringe 10, the user must lock the fiber 22 into an ejected position so that the sample can be disposed on the fiber through absorption, adsorption, static charge, etc. The user uses a digit (typically a thumb) on the thumb actuator 14. The thumb actuator 14 slides into the handle 12 until it reaches a point where the camming system prevents the fiber 22 from being retracted into the protective sheath 28. At this time in the procedure, the user does not have to keep a digit on the thumb actuator 14 in order to keep the fiber 22 extended from the protective sheath 28. The user then holds the fiber 22 in the sample for an appropriate amount of time as known to those skilled in the art.
In this first embodiment of the syringe 10, the user presses the thumb actuator 14 again in order to move the cam mechanism 16 to a different position that allows the fiber 22 to be retracted within its protective sheath 28. The syringe 10 is then moved to storage or taken to a chemical analysis station where the sample absorbed by the fiber 22 is retrieved and analyzed.
It should be noted that the camming system as described in the first embodiment can be modified to operate in a different manner. For example, a camming mechanism can also be actuated by the thumb, but include a locking release that is reachable on an outside of the handle 12. Thus, releasing the extended fiber 22 would consist of moving a tab or other release means that is disposed on the side of the handle 12.
It is noted that once the fiber 22 has been extended from outside its protective sheath 28, it is also possible to attach the syringe 10 to a container holding a sample. Thus, the syringe 10 enables “hands-free” operation while the sample is being absorbed. However, this is an optional aspect of the present invention, and not a requirement of the first embodiment.
Once the sample has been obtained, the fiber 22 is retracted inside the protective sheath 28. The protective sheath 28 not only protects the sample that has been absorbed by the fiber 22, but also protects the user or other persons present from the chemical in the sample. The user releases the cam mechanism 16 and retracts the fiber 22 inside the protective sheath 28 by actuating the thumb actuator 14 a second time.
The first embodiment described above describes a camming system that locks the fiber 22 into a single desired position external of its protective sheath 28 while the sample is being obtained. However, in an alternative embodiment, it is envisioned that the camming system incorporates means for enabling the fiber 22 to be exposed in ever-increasing lengths outside the protective sheath 28. Accordingly, it is envisioned that in one alternative embodiment, the fiber 22 may be exposed using pre-set incremental lengths upon multiple actuations of the thumb actuator 14 until the fiber is exposed to a maximum ejected length.
In yet another alternative embodiment, it is envisioned that the fiber 22 may be exposed in a non-incremental manner, and to any desired non-predetermined length, up to the maximum length of the fiber. It is envisioned that the fiber 22 would thus be ejected a length that is directly proportional to a length that the thumb actuator 14 was pushed into the handle 12.
Once the sample has been obtained, the sample is now safely moved to, for example, an analysis device or a storage device. Examples of the types of analysis that can be performed include mass spectrometry, ion mobility spectrometry, gas chromatography, liquid chromatography, flow injection analysis, etc. What is important to the present invention is that the analysis devices include an injection port for receiving the syringe 10.
Alternatively, the syringe 10 can be coupled to the receiving port 42 by twisting the handle 12, thereby mechanically locking the syringe to the receiving port by providing complementary locking channels in the receiving port. This alternative embodiment would enable hands-free delivery of the sample once the fiber has been ejected into the analysis device 40.
Another important aspect of this first embodiment of the present invention is the embedding of a microchip with memory into the syringe 10. The microchip is used to uniquely identify the sample absorbed by the fiber 22. Thus, the microchip and memory will be referred to collectively hereinafter as an identification (ID) circuit 24. Exact placement of the ID circuit 24 in this first embodiment is near the fiber ejection and retraction end thereof so that it can be easily placed in electrical contact with a device capable of reading data from or writing data to the ID circuit.
The ID circuit 24 enables tracking of a sample disposed on the fiber 22 from a point of origin (where the sample was obtained), through a chain of custody, to final analysis and/or storage. The electronic chain of custody is maintained by employing a recording instrument that can read from and add information to the data stored in the ID circuit 24. The recording instrument can be a stand-alone device having its own interface, or it can be coupled to another device such as a computer that provides an interface. This means that the recording instrument can operate in a stand-alone mode of operation, or be dependent upon another device for communication. The mode of operation is thus independent of any connection to or separation from a chemical analyzer such as the analysis device 40 shown in
In this first embodiment, the ID circuit 24 is any digital memory module and I/O circuitry that enables storage and reading of data that can maintain the electronic chain of custody of the sample. The memory is preferably non-volatile so that data remains safely within the memory even after power is removed. The use of non-volatile memory eliminates any need for a battery in the syringe 10 to preserve data in the memory.
In an alternative embodiment of the present invention, it is envisioned that the ID circuit 24 is simplified even further, and consists only of a memory module. Thus, any recording instrument would have to provide the means for communicating with the memory.
When considering the nature of the memory being used in the first embodiment of the present invention, it is noted that data stored therein cannot be erased after being stored. Thus, while new information can be added to the memory, old information is always retained. The memory can also be read as often as desired without modifying data.
In an alternative embodiment, it is envisioned that a reusable syringe includes an ID circuit 24 that uses memory that can be erased completely. It is important that the memory erasure cannot be selective, to thereby avoid doubt as to the integrity of the electronic chain of custody.
In another alternative embodiment, it is envisioned that a reusable syringe has a replaceable fiber for collecting a sample, and a new ID circuit 24. The fiber 22 and ID circuit 24 would be a single unit that would again ensure integrity of the electronic chain of custody.
Another important aspect of the memory of the first embodiment is that it has stored therein a unique code for the ID circuit 24. By giving each ID circuit 24 a unique code, electronic chain of custody is again ensured because there will be no possibility that two ID circuits will have the same code. Thus, even if the syringe is reusable, a new unique code would still need to be provided for the memory used in the ID circuit 24.
Storing data in the memory of the ID circuit 24 can be accomplished using an appropriate physical and electrical connection. Systems and methods for storing data to and reading data from non-volatile memory are well known to those skilled in the art, and thus the means for accomplishing these tasks is not of particular importance to the present invention. It is the application of memory storage and retrieval techniques as applied to the task of electronic chain of custody that is important for the present invention.
One reason for the requirement of the first embodiment that a physical connection be made between the syringe 10 and the recording instrument before data can be stored on the ID circuit 24, is that this step prevents unwanted tampering with the data stored therein. Thus, it is inappropriate to provide wireless means, such as radio-frequency (RF) or infra-red (IR) means, for storing data in the memory of the ID circuit 24. However, it is possible that RF or IR means for reading data may be permissible, and should be considered to be within the scope of an alternative embodiment of the present invention.
The data that is stored in the non-volatile memory of the ID circuit 24 to create the electronic chain of custody can be selected from information that is typically considered useful for such purposes. For example, such information may include, but should not be considered limited to, time and date that the sample is being taken, the location where the sample is being obtained, an identification code for the operator performing the sampling, storage, or analysis, and a unique identification code for the recording instrument.
The recording instrument that is used to store data to and read data from the ID circuit 24 can be a portable or stationary device. Thus, the recording instrument can be battery powered, or be operated directly from current from a wall socket.
Access to the recording instrument can be provided by any convenient interface. For example, a computer can provide access to the recording instrument and from there to the ID circuit 24 via a USB interface, Firewire, or any other wired access protocol or hardware connection. As mentioned previously, wireless access means might also be provided to read the data stored in the ID circuit 24 in an alternative embodiment. In this case, the ID circuit 24 must also include means for transmitting data stored therein.
The recording instrument might also include a display and keyboard so that it does not have to be accessed through a computer, thereby making it a true stand-alone device. However, size and complexity of the recording instrument will most likely be reduced by providing access through a computer, and thereby avoiding the need for keyboard and display on the recording instrument itself.
A specialized version of the recording instrument is designated as an Analyzer Recording Instrument. The Analyzer Recording Instrument may be designed to provide an interface with a particular analyzer. In the first embodiment, the Analyzer Recording Instrument is configured so that it is pre-programmed with all of the specific requirements of the particular analyzer with which it operates.
To complement the circuit of
While the ID circuit 24 has application for providing chain of custody for a sample absorbed by a fiber 22, the ID circuit can also be used in other devices. For example, a typical hypodermic syringe, a filter for collection of samples from air or other gaseous environments, and a plug sample device for securing samples of solid materials.
Several aspects of the present invention that bear further explanation begin with the fiber 22 when it is formed as a filament to collect liquids, solids or solids in suspensions. Collecting solids in suspensions is illustrated in
A twisted wire 90 should not be considered the only alternative embodiment for collecting samples. For example, braided wires, or a wire with holes drilled therethrough can also provide the desired cavities where solids can be disposed.
Another system for the collection of liquids, solids and solids in suspensions is illustrated by the use of a whisk 100 as shown in
As a last aspect of the invention, a suitable whisk 104 can be created using the following procedure. Three nitinol wires are welded together at one end. The three loose ends of the wires are inserted into a stainless steel tube having an inner diameter of 0.006 inches. A metal spacer is then inserted between the three wires to separate the wires and form the whisk 104. The wires and tube are then disposed in an oven at 500° C. for 5 minutes. The spacer can now be removed, and the memory effect induced on the three wires will now maintain the whisk 104 in the desired shape. The three wires are now removed from the tube, and coupled to a holder that is inserted into the syringe 10.
It is to be understood that the above-described arrangements are only illustrative of the application of the principles of the present invention. Numerous modifications and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of the present invention. The appended claims are intended to cover such modifications and arrangements.
This document claims priority to and incorporates by reference all of the subject matter included in the provisional patent applications, docket number 05-17, having Ser. No. 60/673,745 and filed on Apr. 21, 2005, and docket number 05-18, having Ser. No. 60/673,744, and filed on Apr. 21, 2005.
Number | Date | Country | |
---|---|---|---|
60673745 | Apr 2005 | US | |
60673744 | Apr 2005 | US |