US 20050192489 A1
The present invention provides a swallowable data recorder medical device. The swallowable data recorder medical device includes a capsule including a sensing module for sensing a biologic condition within a body. A recording module is provided including an atomic resolution storage device. The recording module is electrically coupled to the sensing module for recording data representative of the sensed biologic condition in the atomic resolution storage device. A power supply is coupled to the recording module.
23. A method of recording data internally within a human body comprising:
ingesting an inert capsule within a digestive tract of a human body;
sensing a predetermined type of biological condition within the digestive tract with a sensor disposed within the capsule; and
recording the sensed biologic condition as data in an atomic resolution storage device memory module within the capsule while the capsule is in the digestive tract.
24. The method of
retrieving the sensed data from memory module when the capsule is outside of the human body.
25. The method of
capturing the capsule after passage of the capsule through the digestive tract.
26. The method of
transmitting the data from the capsule to a location outside of the human body while the capsule is within the human body.
27. The method of
obtaining an image of a predetermined body location within the digestive tract.
28. The method of
arranging a magnetic member in the capsule prior to the ingesting step;
arranging a magnet positioner outside the body; and
magnetically manipulating the relative position and orientation of the capsule within the digestive tract by using the magnet positioner to move the magnetic member in the capsule.
29. The method of
exposing a chemical sensor array on the surface of the capsule to sense one or more chemical conditions in the digestive tract.
30. The method of
sensing at least one of a relative amount and an absolute amount of at least one or more digestive tract constituents.
31. The method of
sensing a pH of the digestive tract constituents.
32. The method of
exposing an electrically based sensor in the capsule to sense biologic conditions.
33. The method of
sensing a temperature within the digestive tract.
34. The method of
performing the sensing step at a predetermined body location within the digestive tract that corresponds to a known location for the predetermined biologic condition.
35. The method of
identifying the passage of the capsule at a predetermined body location within the digestive tract using at least one of a radiographic technique and an ultrasonic technique.
36. The method of
recording sensed data continuously within the digestive tract.
37. The method of
initiating and maintaining recording of the sensed data when the sensed data reaches a predetermined value of a predetermined biologic condition.
38. A method of recording data about biological conditions within a human body, the method comprising:
placing a capsule within a digestive track of a human body, the capsule including a sensor and a storage device comprising an atomic resolution storage device;
sensing a biological condition within the human body with the sensor; and
performing one or more logical operations using the sensed biological condition; and
selectively recording the sensed biological condition to the storage device based upon the logical operations.
39. The method of
receiving video of the biological condition via a video receiver.
40. The method of
accessing programmable logic from the storage device.
41. The method of
generating an electron beam current; and
bombarding a storage area of the atomic resolution storage device with the electron beam current to record data representative of the sensed biological condition.
42. The method of
positioning the storage area to be bombarded by the electron beam current.
This patent application is related to Non-Provisional U.S. Patent DISPENSER CAPSULE MEDICAL DEVICE,” having Attorney Docket No. 10002323-1; which is filed on even date herewith, is assigned to the same assignee as the present application, and is herein incorporated by reference.
The present invention relates to intrabody sensors, and in particular an ingestible data recorder capsule medical device which senses and records information within a body.
Obtaining information about biologic conditions on the inside of the body poses at least two basic issues. First, one must place a sensing device in the body at the desired location. For example, to obtain data about biologic conditions on the large intestine or colon, one must insert a sensor at that location. Second, the data obtained must be transmitted from the internal location to a remote location outside of the human body for processing, storage and/or analysis.
In one example, a conventional endoscope inserted within a colon can obtain internal information about the colon, such as an image of any polyps in the colon, and then transmit that image to a remote location for real time viewing and/or storage. Unfortunately, use of an endoscope is quite invasive requiring insertion of a probe within the colon and simultaneous extension of communication lines from the probe to a location outside of the colon. Moreover, in addition to manual insertion, this method requires manually maintaining the position of the sensing device, e.g. probe, within the body. Accordingly, only locations within the body that are reachable by insertable probes can be monitored using this method.
In another example, an inert, ingestible medical capsule is known which is capable of sensing temperature within the digestive tract and then transmitting that temperature data to a receiver located remotely outside of the body. Since the capsule is inert, i.e. non-digestible, the capsule can be reused for subsequent procedures. Use of this medical capsule requires the patient to be located closely to the remote data receiver for an extended period of time to insure that the sensed data is properly transmitted to the remote receiver.
Perhaps more importantly, this conventional capsule is limited to sensing a single type of data, e.g. temperature. Moreover, the amount of data recorded remotely is limited by the size and strength of components located within the capsule, such as the size and amount of memory storage available within the capsule, the size and strength of transmitter in the conventional capsule, as well as by the associated wireless communication technique. Naturally, these constraints artificially limit the amount and types of biologic data that could otherwise be sensed and recorded throughout the digestive tract since the biologic information available is virtually limitless.
Accordingly, conventional intrabody sensors have several limitations. First, manual insertion of sensors limit the number and type of body locations that can be monitored and also require extensive remote (i.e. outside of the body) equipment support during the procedure. Second, more mobile sensors, such as ingestible capsules, require a remote receiver for receiving data transmitted from the capsule. This requirement forces the patient to remain relatively stationary for a protracted period of time during the procedure, or forces the patient to wear some form of remote receiver. Finally, the conventional capsule is limited in the amount and type of data sensed and recorded.
The present invention provides a swallowable data recorder medical device. The swallowable data recorder medical device includes a capsule enclosing a sensing module for sensing a biologic condition within a body. A recording module is provided including an atomic resolution storage device. The recording module is electrically coupled to the sensing module for recording data representative of the sensed biologic condition in the atomic resolution storage device. A power supply is coupled to the recording module.
In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.
The present invention provides a swallowable data recorder capsule medical device which internally senses and internally records information about biologic conditions within the digestive tract of a body. The capsule is inert and therefore ingestible and passable through the digestive tract without being consumed. Accordingly, the swallowable sensor and recorder optimally is used in sensing and recording information about the digestive tract or about chemical conditions or conditions within the digestive tract that are indicative of conditions in other organs (e.g., skin). Preferably all of the biologic information sensed within the digestive tract is recorded immediately in an atomic resolution storage device or atomic resolution memory within the capsule while the capsule is in the digestive tract. The sensed data is conveniently retrievable from the atomic resolution storage device memory after the capsule is captured outside of the body.
The atomic resolution storage device memory used in the swallowable data recorder capsule medical device according to the present invention is subminiature in size, allowing it to be contained within a swallowable capsule, has low power requirements, and provides for non-volatile storage of large amounts of data, including video. The term “atomic resolution storage device” memory as used herein is defined as a non-volatile memory storage device capable of storing a large volume of data, such as megabytes to gigabytes of data points, within a relatively small storage area and requiring very low power consumption. The atomic resolution storage device includes a field emitter, a storage medium, and a micromover and associated circuitry for the reading and writing of data. Preferably, the atomic resolution storage device includes a plurality of spaced apart field emitters, wherein each field emitter is responsible for a number of storage areas on the storage medium.
As shown generally in
Capsule 10, particularly its shell 12, preferably is made of or coated with one or more of the following inert materials: Teflon (i.e., polytetrafluouroethylene); glass; ceramic; or other materials known to those skilled in the art. Other suitable materials will become apparent to those skilled in the art after reading the present application. Capsule 10 preferably has a size as large as the digestive tract will allow, such as five millimeters in diameter, and preferably has a generally rounded oblong shape, as shown in
Capsule 10 is capable of continuously sensing biologic conditions and continuously recording that sensed data within the capsule 10. Alternatively, each of the sensing and recording functions can be selectively controlled using remote wireless communication techniques for selective activation at a predetermined body location or at a predetermined point in time. Accordingly, as shown in
Sensors 50, 52 further define sensing module 14 of
Controller 54 regulates communication between sensors 50, 52 and memory 54, communication between memory 54 and any remote controllers outside of the human body, and communication with programmable logic component(s) 58. Finally, controller 54 operably controls communication interface 62 and preferably includes a central processing unit or one or more other devices capable of performing a sequence of logical operations. In one preferred embodiment, controller 54 is a microprocessor. In another embodiment, controller 54 includes one or more logic gates located within memory 56.
Memory or storage device 56 is preferably an ultra-high capacity storage device, and which is more preferably of a silicon-based construction. In one preferred embodiment, memory 56 is an atomic resolution storage device capable of storing a large volume of data, such as megabytes to gigabytes of data points, within a relatively small storage area. The atomic resolution storage device is a low power consumption storage device, requiring only about 0.1 watts or less to operate. In one preferred embodiment, ARS module 70 has a size of about 1 square millimeter, suitable to be carried within a swallowable medical capsule. In addition, ARS module can include its own modules that correspond to the functions of programmable logic 58 and/or controller 54. Finally, other subminiature memory devices, known to those skilled in the art, that have a high storage capacity with relatively low power consumption can be used in place of ARS module. However, these alternative devices may limit the volume and quality of data recorded since these devices will not be as powerful as ARS module 70 relative to the power consumption requirements and amount of memory storage.
One atomic resolution storage device suitable for use in the swallowable data recorder capsule medical device according to the present invention is disclosed in U.S. Pat. No. 5,557,596 to Gibson et al., issued Sep. 17, 1996, entitled “Ultra-High Density Storage Device.” Other suitable ultra-high density storage devices suitable for use as memory 56 with the swallowable data recorder capsule medical device according to the present invention will become apparent to those skilled in the art after reading the present application. One exemplary embodiment of a suitable ultra-high density storage device (i.e., atomic resolution storage device) suitable for use as memory 56 with the swallowable data recorder capsule medical device according to the present invention is disclosed in further detail later in this application.
A suitable power supply 58 includes a lithium-ion battery, which is relatively non-toxic, as well as other power supplies suitable for in vivo environments.
Communication interface 62 includes a suitable transmission technology, preferable wireless (e.g. ultrasonic, radiofrequency, etc.), that readily permits communication to and from capsule 10 while capsule is in digestive tract 34 and remote transmitter/receiver 21 (
In use, sensors 50,52 of capsule 10 sense biologic data within digestive tract 34 and the sensed data is passed through controller 54 for storage in memory 56. The sensed data is stored in memory 56 and retrieved via communication interface 62 after capture of capsule 10 upon exiting digestive tract 34. Finally, wireless communication system 20 optionally is used in addition to, or as an alternative to, controller 54 and memory 56 to facilitate and retrieving storing sensed data. The most significant aspect of capsule 10 is recording module 16 including memory 56, which permits internally recording within capsule 10 a profile of one or more biologic parameters throughout the entire digestive tract. This feature eliminates the need for transmission of data to a remote receiver as well as expands the type and amount of biologic data sensed and recorded.
In one embodiment, the field emitters are point emitters having relatively very sharp points. Each point emitter may have a radius of curvature in the range of approximately 1 nanometer to hundreds of nanometers. During operation, a pre-selected potential difference is applied between a field emitter and its corresponding gate, such as between field emitter 102 and gate 103 surrounding it. Due to the sharp point of the emitter, an electron beam current is extracted from the emitter towards the storage area. Depending on the distance between the emitters and the storage medium 106, the type of emitters, and the spot size (bit size) required, electron optics may be utilized to focus the electron beams. A voltage may also be applied to the storage medium 106 to either accelerate or decelerate the field-emitted electrons or to aid in focusing the field-emitted electrons.
In one embodiment, casing 120 maintains storage medium 106 in a partial vacuum, such as at least 10−5 torr. It is known in the art to fabricate such types of microfabricated field emitters in vacuum cavities using semiconductor processing techniques. See, for example, “Silicon Field Emission Transistors and Diodes,” by Jones, published in IEEE Transactions on Components, Hybrids and Manufacturing Technology, 15, page 1051, 1992.
In the embodiment shown in
As will be described, the field emitters are responsible to read and write information on the storage areas by means of the electron beams they produce. Thus, field emitters suitable for use in storage device 100 are the type that can produce electron beams that are narrow enough to achieve the desired bit density on the storage medium, and can provide the power density of the beam current needed for reading from and writing to the medium. A variety of ways are known in the art that are suitable to make such field emitters. For example, one method is disclosed in “Physical Properties of Thin-Film Field Emission Cathodes With Molybdenum Cones,” by Spindt et al, published in the Journal of Applied Physics, Vol. 47, No. 12, December 1976. Another method is disclosed in “Fabrication and Characteristics of Si Field Emitter Arrays,” by Betsui, published in Tech. Digest 4th Int. Vacuum Microelectronics Conf., Nagahama, Japan, page 26, 1991.
In one embodiment, there can be a two-dimensional array of emitters, such as 100 by 100 emitters, with an emitter pitch of 50 micrometers in both the X and the Y directions. Each emitter may access tens of thousands to hundreds of millions of storage areas. For example, the emitters scan over the storage areas with a periodicity of about 1 to 100 nanometers between any two storage areas. Also, all of the emitters may be addressed simultaneously or sequentially in a multiplexed manner. Such a parallel accessing scheme significantly reduces access time, and increases data rate of the storage device.
Micromover 110 can also be made in a variety of ways, as long as it has sufficient range and resolution to position the field emitters over the storage areas. As a conceptual example, micromover 110 is fabricated by standard semiconductor microfabrication process to scan storage medium 106 in the X and Y directions with respect to casing 120.
In another embodiment, the electron beam currents are rastered over the surface of storage medium 106 by either electrostatically or electromagnetically deflecting them, such as by electrostatic deflectors or electrodes 125 (shown in
In one method, writing is accomplished by temporarily increasing the power density of the electron beam current to modify the surface state of the storage area. Reading is accomplished by observing the effect of the storage area on the electron beams, or the effect of the electron beams on the storage area. For example, a storage area that has been modified can represent a bit 1, and a storage area that has not been modified can represent a bit 0, and vice versa. In fact, the storage area can be modified to different degrees to represent more than two bits. Some modifications may be permanent, and some modifications may be reversible. The permanently modified storage medium is suitable for write-once-read-many memory (WORM).
In one embodiment, the basic idea is to alter the structure of the storage area in such a way as to vary its secondary electron emission coefficient (SEEC), its back-scattered electron coefficient (BEC), or the collection efficiency for secondary or back-scattered electrons emanating from the storage area. The SEEC is defined as the number of secondary electrons generated from the medium for each electron incident onto the surface of the medium. The BEC is defined as the fraction of the incident electrons that are scattered back from the medium. The collection efficiency for secondary/back-scattered electrons is the fraction of the secondary/back-scattered electrons that is collected by an electron collector, typically registered in the form of a current.
Reading is typically accomplished by collecting the secondary and/or back-scattered electrons when an electron beam with a lower power density is applied to storage medium 106. During reading, the power density of the electron beam should be kept low enough so that no further writing occurs.
One embodiment of storage medium 106 includes a material whose structural state can be changed from crystalline to amorphous by electron beams. The amorphous state has a different SEEC and BEC than the crystalline state, which leads to a different number of secondary and back-scattered electrons emitted from the storage area. By measuring the number of secondary and back-scattered electrons, one can determine the stage of the storage area. To change from the amorphous to crystalline state, one increases the beam power density and then slowly decreases it. This heats up the amorphous and then slowly cools it so that the area has time to anneal into its crystalline state. To change from crystalline to amorphous state, one increases the beam power density to a high level and then rapidly decreases the beam power. To read from the storage medium, a lower-energy beam strikes the storage area. An example of such type of material is germanium telluride (GeTe) and ternary alloys based on GeTe. Similar methods to modify states using laser beams as the heating source have been described in “Laser-induced Crystallization of Amorphous GeTe: A Time-Resolved Study,” by Huber and Marinero, published in Physics Review B 36, page 1595, in 1987, and will not be further described here.
There are many preferred ways to induce a state change in storage medium 106. For example, a change in the topography of the medium, such as a hole or bump, will modify the SEEC and BEC of the storage medium. This modification occurs because the coefficients typically depend on the incident angle of the electron beam onto the storage area. Changes in material properties, band structure, and crystallography may also affect the coefficients. Also, the BEC depends on an atomic number, Z. Thus, one preferred storage medium has a layer of low Z material on top of a layer of high Z material or vice versa, with writing accomplished through ablating some of the top layer by an electron beam.
Field emitters may be noisy with the magnitude of the electron beam current varying with respect to time. Moreover, the gap distance between the tips of the emitters and the surface of the storage medium may vary. If the information stored were based on tunneling current, then the gap distance may be extremely crucial. However, the application presently disclosed depends on field emitters, and not directly on the emitted electron beam current, but rather on the effect of the beam. At least two ways may be used to alleviate the problem of the emitters being noisy. One way is to connect constant current source 154 to field emitter 102. This source will control the power density of electron beam current beam 156. Although this method would not help storage techniques using the magnitude of the field emitted current as the signal, this method reduces the field emitter noise significantly. Another way to alleviate the field-emitter noise is to separately measure the emitted electron beam current and use it to normalize the signal current. As the electron beam current varies, the signal current varies correspondingly. On the other hand, the normalized signal current remains the same to indicate the state of the storage area.
Sensing module 90 preferably is a silicon-based module, which includes various cavities filled with the desired type of sensing substance and/or circuitry to form each sensor 92, 94, 96. For example, sensor 90 preferably is constructed from a silicon surface bearing a chemically sensitized film for each sensor 92, 94, 96, wherein the film reacts upon the presence of a particular biologic constituent, producing an electrical response in the silicon surface that is recorded in memory as sensed data. Suitable sensor modules 90 are known in the art, such as are available from Agilent Technologies (e.g., an Agilent 2100 bioanalyzer).
For example, using these techniques sensor 92 can be selected to sense absolute values of pH, or sense pH only below a certain value, e.g. 5. Sensor 92 also could be selected to sense any pH value to provide continuously variable data on pH.
Alternatively, sensor 92 could sense the presence of any expected digestive tract constituent such as bile fluids, or any unexpected digestive tract constituent such as blood, or cancer cells. For example, one of the sensors 92, 94, 96 could be chemically sensitive to cancer cells. Upon a sensor detecting a cancer cell constituent, the data is recorded. After retrieving the data outside of the body, the location in digestive tract 34 is determined based on the character of the sensed data and is used to target future diagnostic and/or therapeutic techniques to that location. Alternatively, radiographic or wireless communication techniques can be used to identify the location of capsule 10 upon the sensed data triggering a transmission signal to a remote receive.
This type of sensor array 90 conveniently permits a large number of the same type or different type of sensors to be placed on small electrically communicable module. This arrangement is preferred where many different types of tests must be performed. For example, in investigative research, comprehensive information can be gathered about many biologic conditions with one pass of capsule 10, rather than checking for a single biologic condition with each pass of capsule 10.
As shown in
A swallowable medical capsule of the present invention has many advantageous features. Foremost, after sensing biologic conditions within a digestive tract, the capsule immediately records that sensed biologic data in memory within the capsule while still in the digestive tract. The sensed data is retrieved later after the capsule is captured upon exit from the digestive tract.
The ultra large storage capacity of the memory within the capsule along with the use of silicon-based surface sensing modules (or other types of sensors, e.g., imaging) permits large volumes of many different types of biologic conditions to be sensed and recorded internally for later study. In addition, this internal recording feature alleviates the prior art need to immediately transmit sensed data from the capsule inside the digestive tract to a receiver remotely located away from the capsule outside of the body. Accordingly, a patient no longer must remain in close proximity to a receiving device during the time period that the capsule is within the human body. Rather, the patient can move freely, making more likely that such a capsule will be used. Nevertheless, for ultimate flexibility, the internal recording ability also can be used at the same time as known wireless data transmission techniques to both immediately transmit sensed data to a remote location and to record the data internally within the capsule. Finally, unlike the use of endoscopes, use of the capsule is essentially non-invasive, which will likely cause more patients to agree to a diagnostic sensing procedure using the capsule. The capsule may also be implanted at a desired location within a body for long periods of time, sense and record data, and be removed at a later date for data retrieval and analysis.
Although specific embodiments have been illustrated and described herein for purposes of description of the preferred embodiment, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent implementations calculated to achieve the same purposes may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. Those with skill in the chemical, mechanical, electromechanical, electrical, and computer arts will readily appreciate that the present invention may be implemented in a very wide variety of embodiments. This application is intended to cover any adaptations or variations of the preferred embodiments discussed herein. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof.