Antenna for in-vivo imaging system

ANTENNA FOR IN-VIVO IMAGING SYSTEM

FIELD OF THE INVENTION

The present invention relates generally to an in-vivo imaging system suitable for imaging the gastrointestinal (Gl) tract or other body lumens. In particular, it is related to an imaging device and an antenna for transmitting for example captured image signals.

BACKGROUND OF THE INVENTION

Known devices may be helpful in providing in-vivo imaging. Autonomous in-vivo imaging devices, for example in-vivo imaging devices, such as swallowable or ingestible capsules or other devices may move through a body lumen, imaging as they move along. Some of these devices use a wireless connection to transmit image data.

In some in vivo devices, such as ingestible imaging capsules, the components within the capsule, such as an antenna(s), may be arranged on a board or on several boards, for example on a printed circuit board (PCB). In some cases the boards are aligned along an axis of the capsule and are electrically connected by a plurality of wires.

Several factors have so far limited the extent to which the size of an imaging device can be reduced. A first factor may be the size of the boards e.g. the PCB located in the device. Another factor limiting the size reduction or space usage in imaging devices may be the size of the antenna for transmitting (and/or receiving) data such as image data.

SUMMARY OF THE INVENTION

The present invention provides, according to some embodiments, an in vivo imaging device comprising a circuit board, for example a circuit board having one or more rigid sections or portions, and one or more flexible sections or portions. In some embodiments, the rigid sections and flexible sections may alternate.

Several factors may enable manufacturing of circuit boards, which may be shorter in length and lighter in weight, and which may be folded to smaller sizes

Embedded Antenna and thus provide for smaller sized in-vivo devices e.g. capsules. The first factor may be designing new components that may be for example smaller in size and economized in shape, for example redesigning an antenna so that it takes up less space in the circuit board. The second factor may be more efficient utilization of surface and cavity space within the in vivo device, for example more efficient use of the circuit board surface.

According to one embodiment of the present invention, an example for economizing space usage may be by employing rigid sections for several components. For example, according to one embodiment of the present invention a rigid section may support both an illumination system and/or an antenna, and thus decrease the number of rigid sections on the circuit board. Efficient and economized circuit board setup may enable circuit board folding into smaller sizes which take up less space, and thus provide for smaller sized in-vivo devices.

According to some embodiments of the present invention, the in vivo imaging device may include an image sensor and/or imager. The device may further include an illumination system and/or a transmitter and an antenna for transmitting image data to a receiving system.

According to some embodiments of the present invention, some components in the device, for example, the illumination system and the antenna may be disposed or attached to one of the rigid circuit board sections.

According to some embodiments of the present invention, the circuit board may be manufactured or pre-provided to include one or more integrated antenna(s).

According some embodiments of the present invention one or more rigid portions may include an illumination system or one or more illumination units, for example a Light Emitting Diodes (LEDs), a LED ring, an illumination ring, an illumination assembly, or other suitable illumination systems on a first surface of the rigid portion and an antenna on a second surface of the rigid portion.

According to some embodiments of the present invention, one or more illumination units, for example a LED ring or other suitable illumination systems

Embedded Antenna and the antenna may be integrated or embedded, for example, within a rigid portion of the circuit board. According to some embodiments of the present invention the antenna may be combined with or attached to other elements in the in vivo imaging device so as to possibly reduce the amount of space taken up by it.

According to some embodiments of the present invention there is provided an imaging device wherein a transmitter may include a voltage-controlled oscillator (VCO), and an antenna may be resonating loop of the VCO.

According to some embodiments of the present invention there is provided an imaging device which may include a shell or housing, and wherein an antenna may be disposed on the shell or housing.

According to another embodiment of the present invention, the antenna may be disposed along a perimeter of the inner side of shell or housing, and the perimeter may lie in a plane parallel to a short axis of the housing; in a plane forming a non-perpendicular angle with a long axis of the housing; or in a plane parallel to a long axis of the housing, or wherein the antenna may be disposed along a perimeter of the outer side of the shell or housing.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is herein described, by way of example only, with reference to the accompanying drawings, in which like components are designated by like reference numerals, wherein:

Fig. 1 shows a schematic diagram of an in vivo imaging device, according to one embodiment of the present invention;

Fig. 2 is a schematic illustration of an antenna, inside a shell of an imaging device, in accordance with some embodiments of the present invention;

Fig. 3 is a schematic illustration of an antenna, inside a shell of an imaging device, comprising a horizontally oriented air coil, in accordance with some embodimehts of the present invention;

Embedded Antenna

Figs. 4A- 4C are schematic illustrations of vertical antennas imprinted on a housing of an in-vivo device, in accordance with some embodiments of the present invention;

Fig. 5 is a schematic diagram of an in vivo imaging device, in accordance with some embodiments of the present invention;

Figs. 6A and 6B schematically illustrate a top side view and a bottom side view, respectively, of a circuit board in accordance with another embodiment of the present invention;

Figs. 6C and 6D schematically illustrate a top view and a bottom view, respectively, of a circuit board in accordance with some embodiments of the present invention;

Fig. 6E schematically illustrates, an antenna in accordance with some embodiments of the present invention;

Fig. 7A is a cutaway view depicting a rigid portion of a circuit board, an antenna and a transmitter, according to some embodiments of the present invention;

Figs. 7B-7C schematically illustrates a top view and a side view, respectively, of a rigid section of a circuit board, in accordance with some embodiments of the present invention;

Figs. 8A-8C schematically illustrates an antenna, according to some embodiments of the present invention;

Figs. 9A and 9B schematically illustrate a three-dimensional view of a circuit board and an antenna, in accordance with some embodiments of the present invention;

Fig. 10 is a block-diagram illustration of an exemplary transmitter containing a voltage-controlled oscillator, in accordance with some embodiments of the present invention;

Fig. 11A-11D a block-diagram illustrations of an electric circuit, in accordance with some embodiments of the present invention;

Embedded Antenna

Fig. 12 is a block-diagram illustration of an imprinted antenna, in accordance with some embodiments ofthe present invention; and

Fig. 13 is a schematic flow-chart of a method of manufacturing an in vivo imaging device in accordance with some embodiments of the invention.

It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.

DETAILED DESCRIPTION OF THE INVENTION

The following description is presented to enable one of ordinary skill in the art to make and use the invention as provided in the context of a particular application and its requirements. Various modifications to the described embodiments will be apparent to those with skill in the art, and the general principles defined herein may be applied to other embodiments. Therefore, the present invention is not intended to be limited to the particular embodiments shown and described, but is to be accorded the widest scope consistent with the principles and novel features herein disclosed. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention.

Reference is now made to FIG. 1, which schematically illustrates an in vivo imaging device according to an embodiment of the present invention. According to one embodiment the device 40 typically comprises an optical window 21 and an imaging system for obtaining images from inside a body lumen, such as the Gl tract. The imaging system may include one or more

Embedded Antenna illumination sources 23, such as a white LED, an imager 8, such as a CMOS imaging camera and an optical system 22 which focuses the images onto the imager 8. The illumination source 23 illuminates the inner portions of the body lumen through optical window 21. Device 40 may further include a transmitter 12 and an antenna 27 for transmitting image signals from the imager 8, and a power source 2, such as a silver oxide battery, that provides power to the electrical elements of the device 40.

According to some embodiments of the present invention, device 40 typically may be or may include an autonomous swallowable capsule, but device 40 may have other shapes and need not be swallowable or autonomous. Embodiments of device 40 are typically autonomous, and are typically selfcontained. For example, device 40 may be a capsule or other unit where all the components are substantially contained within a container or shell, and where device 40 does not require any wires or cables to, for example, receive power or transmit information.

According to some embodiments of the present invention, the device 40 may be capsule shaped and can operate as an autonomous endoscope for imaging the Gl tract. However, other devices, such as devices designed to be incorporated in an endoscope, catheter, stent, needle, etc., may also be used, according to embodiments of the invention. Furthermore, the device 40 need not include all the elements described above. For example, the device 40. need not include an internal light source or an internal power source; illumination and/or power may be provided from an external source, as known in the art.

The system and method of the present invention may be used with or in an imaging system such as that described in US Patent Application, Serial No 09/800,470, entitled A DEVICE AND SYSTEM FOR IN-VIVO IMAGING, filed on March 8, 2001. A further example of an imaging system with which the system and method of the present invention may be used is described in United States Patent Number 5,604,531 to Iddan et al., entitled IN-VIVO VIDEO CAMARA

Embedded Antenna

SYSTEM, filed on January 17, 1995. Both these publications are assigned to the common assignee of the present application and are hereby incorporated by reference. Alternatively, the system of the present invention may be utilized in any suitable imaging device providing images of a body lumen or cavity. For example, a circuit board according to an embodiment of the invention may be utilized in probes used for in vivo imaging, such as endoscopes.

According to one embodiment of the present invention, the various components of the device 40 are disposed on a circuit board 30 including rigid and flexible portions; preferably the components are arranged in a stacked vertical fashion. For example, one rigid portion 31 ofthe circuit board may hold a transmitter and possibly an antenna 27. Another rigid portion 33 of the circuit board may include, for example, an illumination source 23 lighting system, such as one or more LEDs or other illumination system, and an image sensor 8 on one side; the other side of this rigid portion 33 may include, for example, a contact for battery or power source 2. According to some embodiments of the present invention, each rigid portion of the circuit board may be connected to another rigid portion of the circuit board by a flexible connector portion (e.g. 32 and 32’) of the circuit board. In alternate embodiments, other arrangements of components may be placed on a circuit board having rigid portions connected by flexible portions.

In alternate embodiments, a circuit board having rigid portions and flexible portions may be used to arrange and hold components in other in vivo imaging devices, such as a swallowable capsule measuring pH, temperature or pressure, or in a swallowable imaging capsule having components other than those described above. Such circuit boards may be similar to embodiments described in US application number 10/879,054 entitled IN VIVO DEVICE WITH FLEXIBLE CIRCUIT BOARD AND METHOD FOR ASSEMBLY THEREOF, and US application number 60/298,387 entitled IN VIVO IMAGING DEVICE WITH A CIRCUIT BOARD HAVING RIGID SECTIONS AND FLEXIBLE SECTIONS, each incorporated by reference herein in their entirety.

Embedded Antenna

Fig. 2 is a schematic illustration of a vertical antenna 226 comprising a vertically oriented air coil, according to some embodiments of the present invention. When used herein, vertical and horizontal are relative terms, and may be interchangeable based on perspectives of the viewer, or based on specific embodiments. In one embodiment, antenna 226 may be included within an invivo device 40, having a shell or housing 205, and antenna 226 may be oriented so that it circles along axis “A” of the housing 205 of device 40 and extends more or less along axis A. In other words, a plane formed by the loop(s) or coil(s) of antenna 226 may be relatively perpendicular to axis A, or may be oriented relatively horizontally and parallel to the plane of a supporting board 204, e.g., a print-circuit-board (PCB) or other holders. While in one embodiment the loop(s) or coil(s) may be substantially circular, in other embodiments they may have other shapes, such as an oval, a square, etc.

According to some embodiments of the present invention, the printed circuit board (PCB) 204 and loops formed by antenna 226 may be oriented in a plane parallel to or substantially parallel to a short axis “B” of the housing 205 of device 40, and/or may be perpendicular to or substantially perpendicular to long axis A. Deviations from “horizontal” and “vertical” positions, such as angling, from long axis A or short axis B may be used: In one embodiment, antenna 226 may be disposed along the perimeter of device 40. For example, antenna 226 may be placed against or on the shell or housing, or incorporated within the shell or housing 205, for example, as is discussed below.

Fig. 3 shows an antenna 327, according to one embodiment of the invention, of a horizontal air coil, which is oriented such that loop(s) or coil(s) of antenna 327 may circle along short axis B of device 40, according to some embodiments of the present invention. According to one embodiment of the present invention, a plane or planes formed by the loop(s) or coil(s) may be perpendicular to a supporting board 304 (e.g. a circuit board), and may be in parallel with long axis A. Compared with antenna 327, the air coil of antenna 226 in Fig. 2 has a larger radius, referred herein as “R-!״, than radius of the air coil of conventional antenna 327, referred herein as “R₂”. For example, R₁ may be more

Embedded Antenna than twice R₂. Consequently, the coil area of antenna 226, kR!², is bigger, for example, more than four times bigger, than that of the coil area of antenna 327, πΗ₂². On the other hand, antenna 226 may have a less number of turns of coil than that of antenna 327. For example, antenna 327 may have, for example, seven turns of coil and, according to some exemplary embodiments of the invention; a vertical antenna 226 may have, for example, two to three turns of coil.

In another embodiment, for example when using a spherically shaped invivo device, the antenna may form a coil or set of coils lying in a plane or planes that are parallel to a circuit board or support on which the antenna is mounted, rather than forming a coil or set of coils in a plane or planes perpendicular to the support or circuit board. Further, in an embodiment in a spherically shaped device, the antenna may be disposed around the perimeter of the device, for example around the inside of a shell or housing of the device. Other dimensions and shapes for the antenna and for the in-vivo device, and other number of turns of coil may be used.

According to one embodiment of the present invention, a cumulative height or length (depending on the perspective) “H” of a series of stacked coils or loops, as is depicted by antenna 226 in Fig. 2, may be less than the diameter “D” of the stacked coils or loops, e.g., < 20%. H may be significantly less than D, e.g., < 5%, when antenna 226 is imprinted on a PCB, for example, as described in detail below. The set of loops or coils (when used herein the term “set” may include one unit) may extend along the length H. According to another embodiment of the present invention, diameter D of two or more loops or coils of antenna 226 may be slightly different from each other. For example, one coil may be slightly smaller than, and therefore may be contained within, another coil when antenna 226 is imprinted on a PCB, or other supporting medium and so different coils may be formed in substantially the same plane.

Efficiency of an antenna is generally measured by the amount of power radiated as a percentage of total power consumed by the antenna. The efficiency is in general determined by characteristics of the antenna among which is

Embedded Antenna radiation resistance, “Rr and dissipating factor, “Rd”, as are known in the art. The radiation resistance, Rr, is an indication of radiated power by an antenna, and usually the bigger the radiation resistance is the more power the antenna radiates. The value of radiation resistance may be proportional to the square of number of turns of coil multiplied by the square of coil area, e.g., Rr ~ (NA)², wherein “N” is the number of turns of coil and “A” is the coil area of the antenna. The dissipating factor, Rd, may be a resistance inherent to the conducting material of coil. Therefore, the efficiency of antenna may be given by Rr/(Rr+Rd) and for antennas used inside an in-vivo device whose dimensions are smaller than, for example, ten percentage of an operational wavelength, Rr«Rd.

According to some exemplary embodiments of the invention, it may be effective to increase the radius of air coil, such as by vertical antenna 226 instead of horizontally oriented antenna 327, in order to increase the amount of power radiated by the antenna.

The efficiency of an antenna may also depend on a coil inductance “L”, and in general it decreases with the increase in L. This is because the amount of a current that flows through an antenna resonator, e.g., coil, and radiates from the antenna, may be inversely proportional to the coil inductance. In general, the coil inductance L is proportional to the square of number of turns of coil multiplied by the square of the radius of coil, e.g., L ~ (NR)², where “R” is the radius of coil. Therefore, in the course of increasing the radius of coil to increase the amount of power radiated by antenna 226 as is described above, in order to counter the effect of increase in the coil inductance due to the increase of coil radius, the number of turns of coil may be reduced. Even though the radiation resistance Rr, which is proportional to the square of number of turns of coil, may decrease due to reduction in the number of turns of coil, it may be possible to increase the overall radiation resistance value of Rr without increasing coil inductance L by increasing R and reducing N accordingly, according to some exemplary embodiments of the invention. This is because the radiation resistance, Rr, is a 4^th power function, and the coil inductance, L, is a 2^nd power function, of antenna

Embedded Antenna radius R, respectively. Meanwhile, both Rr and L are the same function of the number of turns of coil, N.

According to one embodiment of the present invention, an antenna may be made having a geometry of a coil having a radius of less than 10mm; in other embodiments a coil radius of less than 8mm, less than 6mm, less than 5mm, less than 4mm, or less than 3mm may be used. In other embodiments, a total of five or less, for example, turns of coil or loop; three or less turns of coil or loop; or two or less turns of coil or loop may be used. For example, according to one embodiment of the present invention, a geometry of for example vertically oriented antenna may be made having a coil radius of 4mm and a total 2.5 turns of coil. When compared with, for example, a conventional antenna with a horizontally oriented air coil of a radius 1.8mm and 7 turns of coil, the antenna with new geometry may achieve an additional gain by a factor of 3.11, or 4.8dB in terms of radiated power. Other numbers of turns of coil, and other radii may be used.

According to one embodiment of the present invention, in order to keep coil inductance low, an operational radio frequency may be made to be off the resonance frequency of antenna coil, for example, by 40%. In other words, the resonance frequency of antenna coil may be, for example, two and half times higher than the operational radio frequency. Other amounts of offset by the operational frequency may be used depending on individual implementation details.

Fig. 4A is simplified schematic illustration of a vertical antenna 406 imprinted on a shell or housing 5 of an in-vivo device 40, in accordance with some embodiments of the present invention. The imprint of antenna 406 may be, for example, on the inner side or the outer side of the shell or housing 5, and preferably on the inner side. When the imprint of antenna 406 is on the outer side of the shell or housing 5, care may be exercised to ensure that proper electrical connection of antenna 406 to a transmitter 408 is made through, for example, piercing a pin-size hole on the housing wall and the hole is subsequently sealed

Embedded Antenna so that no leakage of any fluid, which may come from the inside of patient’s Gl or lumens, may enter the compartment of device 40. A supporting board 404, which for example may be a PGB, may contain a transmitter 408, a processor 410, and other elements such as, for example, an optional receiver. According to some embodiments of the present invention, antenna 406 may be placed on a perimeter surrounding a long axis of device 40 but need not be. Further, device 40 may not have one axis longer than the other e.g., it may be symmetrical, spherical, etc.

According to some embodiments of the present invention, the in-vivo device 40 may include a shell or housing, which may be one piece but may also be multiple pieces, such as for example a main body piece and an optical dome piece. Typically, the shell or housing is formed from suitable plastic, but may also be made of other materials, such as glass, metal, etc. According to some embodiments of the present invention, an antenna, or a portion of the antenna, or a majority of the antenna, may be placed generally around an inside perimeter of the shell. Preferably, the antenna is disposed around the longest inside perimeter, to increase loop or coil area, but need not be. For example, the device may have a short axis and a long axis, and the perimeter may be a longer perimeter, corresponding to the long axis.

According to some embodiments of the present invention as shown in Fig. 4B, an in-vivo device 40 may include an antenna 416 being imprinted on a shell or housing 5, either inner or outer side of the in-vivo device 40. In order to form maximum achievable coil area, antenna 416 may lie in a plane that is parallel to, or goes through a long axis of device 40.

According to some embodiments of the present invention as shown in Fig. 4C an antenna 426 may be imprinted on the housing 5 of an in-vivo device 40, or device 422, in a non-perpendicular angle relative to the long axis of the housing of device 40. A vertical antenna 426 may have less coil area than in an antenna of 416, but more than in an antenna of 406.

Embedded Antenna

Fig. 5, schematically illustrates an in vivo imaging device according to another embodiment of the present invention. According to one embodiment the device 40 may include an optical window 21 and an imaging system for obtaining images from inside a body lumen, such as the Gl tract. According to one embodiment of the present invention, the imaging system may include an illumination system which may include for example, one or more illumination sources 23, such as a white light emitting diode (LED) and/or an Organic LED (OLED), and/or an illumination ring such as a LED ring or an OLED ring and/or an illumination assembly and/or an hybrid illumination unit, or other suitable illumination units. According to one embodiment of the present invention, the imaging system may include an image sensor for example an imager 8, such as a CMOS imaging camera and an optical system 22 which focuses the images onto the imager 8. According to one embodiment of the present invention, the illumination sources 23 may illuminate the inner portions of the body lumen through optical window 21. According to some embodiments of the present invention, device 40 may include a control unit 14, a transmitter 12 and an antenna 13 for transmitting image signals from the imager 8, and a power source 2, such as a silver oxide battery, that provides power to the electrical elements of the device 40. According to some embodiments of the present invention, outside a patient’s body may be, for example, an image receiver 90 (including, for example, an antenna or an antenna array), a storage unit 91, a data processor 92, and a monitor 93.

According to some embodiments of the present invention, device 40 may communicate with an external receiving and display system (e.g., through receiver 90) to provide display of data, control, or other functions. For example, power may be provided to device 40 using an internal battery, an internal power source, or a wireless system to receive power. Other embodiments may have other configurations and capabilities. For example, components may be distributed over multiple sites or units, and control information may be received from an external source.

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Optionally, according to one embodiment of the present invention, transmitter 12 may include a processing unit or processor or controller, for example, to process signals and/or data generated by imager 8. In another embodiment, the processing unit may be implemented using a separate component within device 40, e.g., controller or processor 14, or may be implemented as an integral part of imager 8, transmitter 12, or another component, or may not be needed. The optional processing unit may include, for example, a Central Processing Unit (CPU), a Digital Signal Processor (DSP), a microprocessor, a controller, a chip, a microchip, a controller, circuitry, an Integrated Circuit (IC), an Application-Specific Integrated Circuit (ASIC), or any other suitable multi-purpose or specific processor, controller, circuitry or circuit. In one embodiment, for example, the processing unit or controller may be embedded in or integrated with transmitter 12, and may be implemented, for example, using an ASIC.

According to one embodiment of the present invention, the various components of the device 40 are disposed on a support, for example a circuit board 3 including rigid and flexible portions; preferably the components are arranged in a stacked vertical fashion, however, other arrangements are possible. For example, according to one embodiment of the present invention, one rigid portion 11 of the circuit board 3 may hold a control unit 14. Another rigid portion 9 of the circuit board may include, for example, an illumination system, such as one or more illumination sources 23 such as LEDs, and/or OLEDs and/or a LED ring or other illumination source, and an imager 8 on one side; the other side of this rigid portion 9 may include, for example, a contact 51 for battery or power source 2. According to one embodiment the battery contact is preferably a spring, such as described below. Another rigid portion 7 of the circuit board 3 may include, for example, another battery contact 53 on one side; the other side of this rigid portion 7 may include, for example a transmitter 12. According to some embodiments of the present invention, each rigid portion of

Embedded Antenna the circuit board may be connected to another rigid portion of the circuit board by a flexible connector portion (e.g. 17 and 17׳) of the circuit board.

According to one embodiment of the present invention, the circuit board 3 may be folded, for example, as shown in Figs. 1. When folded, the battery contacts may contact a set of one or more batteries, e.g., power source 2, which may be sandwiched between two rigid circuit board portions. The circuit board 3 may be folded in various manners, for example, circuit board 3 may have a “2” shape, a “5” shape, a “6” shape, a “C” shape, or other suitable shapes. FIG. 5 schematically shows according to one embodiment of the present invention, a circuit board, arranged as an “S״ with rigid portions 9, 17 and 11 and alternating flexible portions 17 and 17’.

According to some embodiments of the present invention, an antenna 13 may be attached to circuit board 3, or may be integrated or embedded within a layer of circuit board 3. For example according to one embodiment of the present invention an antenna 13 may be attached to rigid portion 9, or may be integrated or embedded within a layer of rigid portion 9. For example, according to one embodiment of the present invention rigid portion 9 or circuit board 3 may be manufactured such that antenna 13 is an integral part of circuit board 3, for example of rigid portion 9. According to some embodiments of the present invention, antenna 13 and rigid portion 9 or circuit board 3 may be an integrative unit, such that antenna 13 may not be easily detached or separated from rigid portion 9 or from circuit board 3, or may be firmly attached to and substantially inseparable from rigid portion 9 or circuit board 3.

According to some embodiments of the present invention, antenna 13 may be formed, manufactured or produced as an integrated or integral part of circuit board 3 or rigid portion 9. For example, a process of manufacturing circuit board 3 or rigid portion 9 may include bonding, gluing, soldering, connecting, or otherwise firmly attaching antenna 13 as a part of circuit board 3 or rigid portion

9. Such manufacturing may result in a pre-provided circuit board 3 or rigid portion

Embedded Antenna having an antenna 13 integrated therein, and may eliminate the need to assemble or further connect antenna 13 to circuit board 3 or rigid portion 9 after the manufacturing process of circuit board 3 or rigid portion 9 is completed.

According to some embodiments of the present invention, the loops of vertical antenna 13 may be imprinted close to the perimeter of circuit board 5 in order to form as much loop area as possible, and thereby increase the efficiency of power radiation by antenna 13.

According to some embodiments of the present invention, when imprinted in the circuit board 3, loops of antenna 13 may be made to have slightly different diameters from each other. For example, one loop may be slightly smaller than, and therefore be contained within, another loop so that different loops may be made in a same layer of the circuit board 3. According to some embodiments of the present invention, a cumulative thickness of the loops may be smaller than diameter D of the in-vivo device 40, e.g., < 20%. In addition, loops of antenna 13 may be made on different layers of the circuit board 3 with substantially same diameters.

Figs. 6A and 6B schematically illustrate a top side view and a bottom side view, respectively, of a circuit board or other suitable holder 600, configured to occupy a minimum of space within device 40, in accordance with some embodiments of the present invention.

According to one embodiment of the present invention, circuit board 600 may include rigid portions 601, 602 and 603, which may be interconnected using flexible portions 611 and 612. Although three rigid portions and two flexible portions are shown, embodiments of the present invention are not limited in this regard, and may include other numbers, orders or combinations of rigid portions and/or flexible portions. According to some embodiments of the present invention, rigid portion 601 may include, for example, an illumination system 632 e.g. a hybrid illumination unit and/or an illumination ring such as a LED ring or an OLED ring. According to some embodiments of the present invention, rigid

Embedded Antenna portion 602 may include an imager 622 on one side; the other side of this rigid portion 602 may include, for example a battery holder 621, e.g., a spring able to hold a battery or other power source in place. According to some embodiments of the present invention, rigid portion 603 may include a transmitter such as an

ASIC 651 and an antenna 623.

According to some embodiments of the present invention, each rigid portion may be equal to or less than 8mm in thickness. According to one embodiment of the present invention the circuit board 600 may include one or more layers, wherein an antenna, for example the antenna 623 may be embedded in one of the layers or partially in all of the layers e.g. by an antenna having a spiral shape with a dimension of depth. For example rigid section 603 may include six layers 631, wherein the antenna 623 may be embedded in one of the layers or in all of the layers. According to one embodiment of the present invention, one of the layers may include an electrical connection which may connect the antenna 623 to, for example ASIC 651 located for example in rigid section 603.

According to one embodiment of the present invention, the layers of the circuit board, for example the antenna may include any sort of known material; according to some embodiments copper is used.

FIGS. 6C and 6D schematically illustrate a top view and a bottom view, respectively, of a circuit board 670 in accordance with some embodiments of the present invention. In some embodiments, circuit board 670 may be used in conjunction with device 40 of FIG. 5, or with other suitable devices and systems for in vivo imaging or in vivo imaging.

According to one embodiment of the present invention circuit board 670 may include, for example, one or more rigid portions and one or more flexible portions. For example, circuit board 670 may include rigid portions 671, 673, 675 and 677, which may be interconnected using flexible portions 672, 674 and 676. Although four rigid portions and three flexible portions are shown, embodiments of the present invention are not limited in this regard, and may include other numbers, orders or combinations of rigid portions and/or flexible portions.

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In some embodiments, rigid portions 671 and 677 may include, for example, one or more illumination units or LEDs 681, and optionally one or more resistors and/or capacitors to regulate or control the power provided to illumination units or LEDs 681.

In some embodiments, rigid portion 673 may include a first imager 691, a transmitter such as an ASIC 692. According to some embodiments of the present invention, rigid portion 675 may optionally include a second imager 693 and/or a processor 694. According to some embodiments of the present invention, an antenna such as a circular loop antenna 678, may be mounted on and/or may be embedded in one or more sections of the circuit board 670. For example, according to one embodiment of the present invention, one part of the antenna 678 may be mounted on rigid portion 671, another part of antenna 678 may be mounted on flexible portion 672, and another part may be mounted on rigid portion and may be connected to ASIC 692.

According to one embodiment, as shown in Fig. 6E, an antenna 698 may be mounted and/or embedded along the entire length of circuit board 699.

Fig. 7A is a cutaway view depicting a rigid portion 703 an antenna 723 and a transmitter 751, according to some embodiments of the present invention. In some embodiments, rigid portion 703 may be an example of rigid portion 670 of Figs. 6A and 6B. According to some embodiments of the present invention the rigid portion 703 may include one or more layers 721, for example six inner layers. According to one embodiment of the present invention, antenna 723 may be embedded and/or printed in one of the layers, and may be electrically interconnected, for example to the transmitter 751. According to one embodiment of the present invention, antenna 723 may be coiled on the inside of rigid portion 703, for example in one of the layers. According to one embodiment of the present invention, rigid portion 703 may be in a cylindrical shape, and antenna 723 may be wrapped around the outside of rigid portion 701.

Figs. 7B-7C schematically illustrate a top view and a side view, respectively, of an inner layer, for example of rigid section 703, in accordance with some embodiments of the present invention. According to some

Embedded Antenna embodiments of the present invention, antenna 723 may communicate electrically, for example, through vias and/or wires and/or electrical contacts that may cross from one side of rigid section 703 to the other through one of the layers. According to one embodiment of the invention electrical wires, for example two printed traces 724 and 734, may be printed and/or molded on one of the layers 421. According to one embodiment of the present invention, each of the printed traces 724 and 734 may be connected either to a transmitter 751, or to other components which may be placed for example on circuit board 603.

Reference is now made to Figs. 8A-8C, which are schematic diagrams illustrating an antenna 823, according to some embodiments of the present invention. According to one embodiment, for example as shown in Fig. 8A, the antenna 823 may be a circular spiral shaped. According to one embodiment of the present invention, for example as shown in Fig. 8B, the antenna 823 may be a square spiral shaped antenna. According to another embodiment ofthe present invention, for example as shown in Fig. 8C, the antenna may be a ring or a boomerang shaped, for example with an internal circle e.g. a rounded hole in its center. Typically, the antenna 823 has compatible measurements for a suitable incorporation into a circuit board, for example into one of the layers in the rigid portion 703. The antenna 823 may be of a different shape other than a ring shape e.g. a rectangular, or of any other form compatible for fitting into an in vivo device, e.g., an ingestible capsule.

Fig. 9A schematically illustrates a three-dimensional view of a circuit board 900 in accordance with some embodiments of the present invention. According to some embodiments of the present invention, circuit board 900 may be an example of circuit board 600 of Fig. 6A and 6B. In some embodiments, circuit board 600 may be used in conjunction with device 40 of FIG. 5 or with other suitable devices and systems for in vivo imaging.

According to one embodiment of the present invention circuit board 900 may include, for example, one or more rigid portions and one or more flexible portions. For example, circuit board 900 may include rigid portions 901 and 902, which may be interconnected using a flexible portion 911. Although two rigid

Embedded Antenna portions and one flexible portion are shown, embodiments of the invention are not limited in this regard, and may include other numbers, orders or combinations of rigid portions and/or flexible portions.

According to one embodiment of the present invention, rigid portions 901 may have mounted on it on one face a lens holder and a LEDs ring 921 having one or more illumination units or LEDs 942, and possibly other components.

According to some embodiments of the present invention rigid portion 901 may optionally include one or more layers and an antenna 953, for example embedded in one of the layers. According to some embodiments of the present invention, rigid portion 902 may include a transmitter 930. The various components may communicate electrically, for example, through wires or electrical contacts embedded in the circuit board 900.

FIG. 9B schematically illustrates a three-dimensional view of a circuit board 960 in accordance with some embodiments of the present invention. According to some embodiments of the present invention, circuit board 960 may be an example of circuit board 600 of Fig. 6A and 6B. In some embodiments, circuit board 600 may be used in conjunction with device 40 of FIG. 5 or with other suitable devices and systems for in vivo imaging or in vivo imaging.

According to one embodiment of the present invention circuit board 960 may include, for example, one or more rigid portions and one or more flexible portions. For example, circuit board 960 may include rigid portions 961 and 962, which may be interconnected using a flexible portion 966. Although two rigid portions and one flexible portion are shown, embodiments of the invention are not limited in this regard, and may include other numbers, orders or combinations of rigid portions and/or flexible portions.

According to one embodiment of the present invention, rigid portions 961 may have mounted on it on one face a transmitter 951, and possibly other components.

According to some embodiments of the present invention flexible portion 961 may optionally include one or more layers and an antenna 923 embedded in one of the inner and/or the upper layers. The various components, for example

Embedded Antenna transmitter 951 may communicate electrically, for example, through vias 924 and/or wires and/or electrical contacts embedded in the circuit board 660.

Fig. 10 is a simplified block-diagram illustration of an exemplary transmitter 1002 containing a voltage-controlled oscillator (VCO) 1012 and using a resonating coil 1016 of VCO 1012 to function as an antenna, according to some embodiments of the present invention.

According to one embodiment of the present invention, a crystal oscillator (OSC) 1004 may provide a relatively stable and accurate reference frequency 1024. The reference frequency 1024 is then fed into a phase lock loop (PLL) 1008. A second input 1026 to the PLL may come from the output of a binary divider 1006, which may properly divide the frequency of an input signal 1032, tapped directly from the output of VCO 1012 for example, and output a signal whose frequency may be sufficiently close to the reference frequency 1024. The PLL 1008 may produce an output voltage signal 1028, which may be close to DC and may be proportional to the relative phase difference of its two input signals, 1024 and 1026. If the reference signal 1024 and the input signal 1026 from divider 1006 are at substantially the same frequency, the output of PLL 1008 may be a constant DC voltage. Any noise on this voltage may be smoothed out by a low-pass loop filter 1010, which then produces a control voltage output 1030. If the two input signals to the PLL 1008 are not identical in frequency, the control voltage output 1030 from the low-pass loop filter 1010 may fluctuate, which may then attempt to drive the VCO 1012 to the correct frequency. Other components or sets of components may be used in transmitter 1002.

According to some embodiments of the present invention, a modulation signal 1022, e.g., a signal from a processor may be a digital binary signal but need not be. According to one embodiment of the present invention, modulation signal 1022 may include imaging data collected by imaging system, and may also include other telemetry data such as pH data, pressure data, battery voltage data and the like. The modulation signal 1022 may be superimposed onto the control voltage signal 1030 of the VCO 1012 to produce a modulated signal 1034. According to some embodiments of the present invention, the modulation

Embedded Antenna may be conducted in a format of frequency modulation (FM), phase modulation (PM), frequency-shifted-key (FSK), phase-shifted-key (PSK), or any other suitable formats.

According to some embodiments of the present invention, a power amplifier may be used to further boost the power of modulated signal 1034 before it is applied to an antenna. However, this may not be an efficient way to power an antenna that is used inside imaging an in-vivo device, e.g., a swallowable capsule, wherein available power sources may be limited. According to some exemplary embodiments ofthe present invention, resonating coil 1014 of VCO 1012 may be used to function as an antenna, and modulated signal 1034 may be radiated by resonating coil 1014 directly. Additionally, relatively large dynamic range of radiation power, for example, 20dB, may be achieved by changing the driving current that flows through VCO 1012.

Fig. 11A schematically illustrates an electric circuit for example a resonant circuit such as a VCO (Voltage Controlled Oscillator) circuit 1101, in accordance with some embodiments of the present invention. According to one embodiment of the present invention, circuit 1101 may include a power amplifier 1102 or a power VCO and an antenna 1123. According to one embodiment of the present invention an inductive value of the antenna, for example antenna 1123 may be determined by the following equation:

f=1/2pNlc

Wherein:

f - CW, frequency value of carrier wave,

L - Inductance value of the resonant circuit, C - Capacitance value of the resonant circuit.

According to some embodiments of the present invention it may be possible to match an antenna inductance to a required value by using additional capacitance and/ or chock. For example according to one embodiment, as shown in Fig. 11B, circuit 1110 may include a capacitance 1111, which may be connected in series to antenna 1123.

Embedded Antenna

According to another embodiment of the present invention, as shown in

Fig. 11C, circuit 1120 may include a chock 1121, which may be connected in series to antenna 1123.

According to another embodiment of the present invention, as shown in Fig. 11D, circuit 1130 may include a capacitance 1131, which may be connected in parallel to antenna 1123.

Fig. 12 is a simplified structural illustration of an imprinted antenna 1202, which may be made upon, for example, a supporting board, a PCB, or a shell or housing of a capsule. Although an exemplary rectangular shape is illustrated in Fig. 12, embodiments of the invention may include antennas imprinted in shapes such as a circular, an oval, or other suitable shapes. As is schematically illustrated in Fig. 12, imprinted antenna 1202 may include a radiating section 604, and an impedance transformer section 606 to provide impedance match between the relatively low impedance of antenna and the relatively high impedance of driving circuitry (not shown) of RF signal. According to some embodiments of the present invention, imprinted antenna 1202 may also contain discrete components 1208, such as for example capacitors and/or resistors at the two far ends of the imprinted loop or coil pattern, for adjustment of antenna parameters, such as, for example, resonating frequency, impedance, and the like.

Fig. 13 is a schematic flow-chart of a method of manufacturing an in vivo imaging device in accordance with some embodiments of the invention. Step 1210 may include manufacturing or providing a circuit board having one or more rigid portions and one or more flexible portions, wherein each rigid or flexible portion may include one or more layers. Step 1320 may include attaching or connecting or embedding an antenna to one of the layers of the circuit board. This may include, for example, attaching the antenna below an illumination unit or other suitable components. Step 1330 may include folding, bending, twisting and/or shaping of the circuit board or a flexible portion of the circuit board, for example, into a pre-defined shape. Step 1340, may include inserting the folded circuit board into a suitable housing adapted or configured for in vivo imaging, for

Embedded Antenna example, a housing of a swallowable capsule. Other suitable operations or methods may be used in accordance with embodiments of the invention.

It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention is defined by the claims which follow.