Ear piece and method of providing continuous physiological detection using a wearable ear piece

Abstract

An ear piece having a light source and an optical sensor arranged to acquire physiological data from the tragus of an ear. At least one additional light source or optical sensor is provided so that there is a back-up. This back-up allows the misaligned ear piece to still have a sufficient number of light sources and optical sensors to continuously acquire physiological data.

Description

Technical Field

[0001] This invention relates to a detector for user physiological information. In particular, this invention relates to a wearable detector worn on the ear. Background Technology

[0002] Many devices capable of detecting physiological changes and worn on the body for extended periods have been proposed. Some of these devices are worn on the wrist, others on the torso, and still others are in the form of earpieces with extensions that can be inserted into the ear canal (see [link to earpiece]). Figure 1 For comparative purposes, it illustrates such prior art where the extension of the earpiece is aligned with direction VV and located within the ear canal.

[0003] However, people engage in a wide variety of activities. Sometimes, simply because the hands are engaged in activities requiring a lot of movement, wearing a device on the wrist is inconvenient. For example, a tennis player cannot wear a physiological monitor on his wrist without risking its accuracy. At other times, it is not convenient for users to wear devices inside their ear canals. For example, a user may have an ear infection, or their ear canals may be too sensitive to tolerate any contact when inserted into the ear canal.

[0004] Therefore, it is desirable to provide an alternative wearable mode that increases the options for users of wearable monitors. Summary of the Invention

[0005] In a first aspect, the present invention provides an earpiece having a shape for fitting into the concha of a user's ear, the earpiece having a surface for contacting the tragus of the ear; and a physiological sensor disposed on the surface such that the physiological sensor can interact with the tragus. Preferably, the physiological sensor includes at least one light source and at least one optical sensor.

[0006] This invention provides an alternative for using the ear canal as a monitoring site. An earpiece that rests solely within the concha of the ear and obtains physiological readings from the tragus of the ear can be used for young children and infants who are less likely to cry due to discomfort.

[0007] Typically, the at least one light source and at least one optical sensor are disposed on a portion of the surface so as to be aligned along the length of the tragus when worn by a user.

[0008] More preferably, the surface has an area that is too large for contact with the tragus of the ear; the physiological sensor further includes: a plurality of sensor components for interacting with the tragus; and the plurality of sensor components are disposed at different positions in the area such that when the position of the ear component in the concha changes and a portion of the area moves to a position where it is no longer in contact with the tragus, another portion of the area remains in contact with the tragus; and at least one of the plurality of sensor components located on the other portion of the area still interacts with the tragus.

[0009] Typically, the sensor components work in conjunction with corresponding portions. For example, the plurality of sensor components are multiple light sources. Therefore, the corresponding portion is an optical sensor. If so, preferably at least one optical sensor is positioned between two of the plurality of light sources arranged in a line, which extends along the length of the tragus when the user wears the device. In this case, the invention provides the advantage of having a backup light source. Even if the earpiece in the concha is not properly aligned with the tragus and one of the light sources is not illuminating the tragus, at least the optical sensor, along with the other light sources still in contact with the tragus, can provide continuous monitoring of the user's physiology.

[0010] Alternatively, the plurality of sensor components can be a plurality of optical sensors. Therefore, the corresponding portion is a light source. If so, preferably at least one light source is positioned between two of the plurality of optical sensors arranged in a line, which extends along the length of the tragus when the user wears the device. In this case, the invention provides the advantage of having a spare optical sensor. Even if the earpiece in the concha is not properly aligned with the tragus and one of the optical sensors is detecting light passing through the tragus, at least the light source and the remaining optical sensors still in contact with the tragus can provide continuous monitoring of the user's physiology.

[0011] Possibly, the multiple sensor components are multiple electrodes of one polarity. In the earpiece, only one electrode of another polarity may be provided for operation with multiple electrodes of the same polarity. Typically, the multiple electrodes are used to measure skin impedance. Alternatively, the multiple electrodes are used to measure electrocardiogram (ECG) signals, thereby providing an ECG.

[0012] Optionally, the surface has an area that is too large for contact with the tragus of the ear; the physiological sensor further includes a first electrode laid across the area to interact with the tragus; such that when the position of the ear changes and a portion of the area moves out of contact with the tragus, another portion of the area remains in contact with the tragus, so that a portion of the first electrode still interacts with the tragus. Thus, the first electrode extends beyond the tragus, and the sliding length of the first electrode across the tragus as the ear rotates within the concha keeps the electrode in contact with the tragus for continuous physiological monitoring. Typically, the physiological sensor further includes a second electrode laid across the area to interact with the tragus; such that when the position of the ear changes and a portion of the area moves out of contact with the tragus, another portion of the area remains in contact with the tragus, so that a portion of the second electrode still interacts with the tragus.

[0013] Preferably, the earpiece further includes a speaker, making the earpiece usable as headphones.

[0014] The headset can wirelessly connect to a smartphone for downloading physiological data acquired by the device. Alternatively, the headset can have a cable connector for wired connection to a smartphone, also for downloading physiological data. This allows devices such as Machintosh... Headphones that do not include any digits inserted into the ear canal include physiological devices that detect information from the tragus.

[0015] In a second aspect, the present invention provides a method for providing continuous physiological monitoring using a wearable earpiece, the method comprising the steps of: providing an earpiece having a plurality of sensor components disposed at different positions on the earpiece; positioning the earpiece in a user's ear such that at least one of the plurality of sensor components interacts with the tragus; allowing the earpiece to move such that at least one of the plurality of sensor components moves to a position where the at least one of the plurality of sensor components can no longer interact with the tragus, and at least another of the plurality of sensor components moves to a position where the at least another of the plurality of sensor components can continue to interact with the tragus.

[0016] Optionally, the plurality of sensor components are a plurality of optical sensors. Alternatively, the plurality of sensor components are a plurality of light emitters. Further alternatively, the plurality of sensor components are a plurality of electrodes.

[0017] This invention proposes that, for a device with an optical physiological detector, the tragus is the suboptimal position within the outer ear structure, while the ear canal is the optimal position, allowing the device to have other functions that mask its physiological detection purpose, such as headphones. The rest of the outer ear—such as the concha—curves too gently for ensuring continuous and isolated contact with the optical detector. Therefore, this invention provides a possible good alternative for using the ear canal to apply the optical detector. Attached Figure Description

[0018] Referring to the accompanying drawings illustrating possible arrangements of the invention will facilitate further description of the invention, wherein the same numbers refer to the same parts. Other embodiments of the invention are also possible, and therefore the specificity of the drawings should not be construed as replacing the generality of the previously described invention.

[0019] Figure 1 Prior art is shown for comparative purposes;

[0020] Figure 1a The structure of the outer ear is shown;

[0021] Figure 2 An embodiment is shown placed within the concha of the outer ear;

[0022] Figure 3 yes Figure 2 A close-up view of an embodiment;

[0023] Figure 4 yes Figure 2 A close-up view of a variant of an embodiment;

[0024] Figure 5 The diagram shows... Figure 4 The advantages provided by the embodiments;

[0025] Figure 6 It is also illustrated. Figure 4 The advantages provided by the embodiments;

[0026] Figure 7 It shows Figure 4 A variation of an embodiment;

[0027] Figure 8 It also shows Figure 4 A variation of an embodiment;

[0028] Figure 8a It shows Figure 8 A variation of an embodiment;

[0029] Figure 9 It also shows Figure 4 A variation of an embodiment;

[0030] Figure 10 It also shows Figure 4 A variation of an embodiment;

[0031] Figure 11 A second embodiment of the present invention is shown;

[0032] Figure 12 Explained Figure 4 A variation of an embodiment. Detailed Implementation

[0033] Figure 1a The structure of the outer ear is shown, including the following structures: antihelix 101, helix 103, cymba conchae 105, superior crus of antihelix 107, triangular fossa 109, inferior crus of antihelix 111, crus of helix 113, tragus 115, conchae cavity (usually referred to as concha) 117, intertragic notch 119, earlobe 121, and antitragus 123.

[0034] The tragus 115 is a small, pointed ridge in the outer ear located anterior to the concha 117 and extends posteriorly over the entire ear canal. The adjacent antitragus 123 extends anteriorly and upwardly.

[0035] Figure 2 The earpiece 200 is shown, which is disc-shaped and has a generally circular shape in cross-sectional view. The earpiece 200 is appropriately sized to be received in the concha 117 of the ear, such that the outer periphery of the earpiece 200 presses against the surface of the tragus 115 facing the antihelix 101.

[0036] Figure 3 A close-up view of the earpiece 200 is shown. A light source 301 and an optical sensor 303 are disposed on the outer peripheral or edge surface of the earpiece 200. The light source 301 is typically a light-emitting diode (LED), and the optical sensor 303 is typically a photodiode, but other light sources and photodetectors can be used. Such a pair of light sources 301 and optical sensors 303 has been used in optical volumetric imaging. In this embodiment, the light source 301 is positioned to emit light into the tragus 115 of the ear. For the purpose of explaining how the earpiece 200 works, Figure 3 The tragus 115 is illustrated as being separated from the light source 301 and the optical sensor 303 by a small distance. In reality, the outer periphery of the earpiece 200 contacts the tragus 115, causing the light source 301 and the optical sensor 303 to be covered by the tragus 115. This ensures that ambient light generally cannot reach the optical sensor 303, and that the light emitted by the light source 301 illuminates as much of the tragus 115 as possible without illuminating the surrounding environment.

[0037] Preferably, the light source 301 emits monochromatic light at frequencies that can be absorbed by blood. Furthermore, although not essential, but also preferably, the optical sensor 303 is capable of selectively detecting light of specific frequencies from the light source 301. This can be achieved by placing a filter on the optical sensor 303 to ensure that only light of the selected frequencies can excite the optical sensor 303.

[0038] Figure 3 The illustration, shown in dashed lines, illustrates how light is emitted from light source 301 and penetrates into the tragus 115. Some of this light is absorbed by the blood in the tissue and converted into heat or other forms of energy. Another portion of the light simply diffuses within the tissue. As a result, the light is scattered within the tragus 115. A portion of the scattered light exits the tragus 115 again at the point where it contacts the optical sensor 303 and reaches the optical sensor 303.

[0039] As blood flows through the tragus 115 and pulsates with the heart's pumping action, the amount of light absorbed by the blood increases and decreases depending on the pulsating blood volume. Consequently, the amount of light reaching the optical sensor 303 after passing through the tragus 115 fluctuates. Using signal analysis, a user's pulse can be analyzed to deduce their cardiac condition, blood pressure, fitness and exercise effectiveness, and even their psychological stress level. For example, by monitoring the degree of cyclical variation between consecutive heartbeats, the user's heart rate variability (HRV) can be calculated. Low HRV indicates high stress levels. Similar signal processing and statistical techniques for monitoring physiological and psychological conditions from the pulse are known and have been developed by numerous research groups, and will not be detailed here.

[0040] Figure 4 Another embodiment 400 is shown, which includes two light sources 301 and an optical sensor 303. The two light sources 301 and the optical sensor 303 are shown disposed on the side of the earpiece 400 and arranged vertically in a row. Typically, the two light sources 301 and the optical sensor 303 are positioned close to each other such that they are both covered by the tragus 115. Preferably, the optical sensor 303 is positioned between the two light sources 301.

[0041] and Figure 3 same, Figure 4 This is a schematic illustration. Although the light source 301 and the optical sensor 303 are shown as spaced apart from the tragus 115 for clarity, those skilled in the art will recognize that the tragus 115 actually covers the light source 301 and the optical sensor 303.

[0042] If the user wears the earpiece 200 correctly, the tragus 115 covers the entire array of light sources 301 and optical sensors 303. Light from both light sources 301 enters the tragus 115 and is either scattered back or reflected and detected by the optical sensors 303. However, if the user inadvertently causes the earpiece 200 to rotate within the concha 117, exposing one of the light sources 301 so that it is no longer covered by the tragus 115, the distance between that light source 301 and the optical sensor 303 may allow the other light source 301, along with the optical sensor 303, to remain covered by the tragus 115.

[0043] Therefore, preferably, the distance between the two light sources 301 is less than the average length of the tragus. Typically, this distance is about 5 mm.

[0044] Figure 5 The following situation is shown, where Figure 4 The earpiece 400 has rotated counterclockwise within the concha 117 of the left ear, and the higher light source 301 in the row of light sources 301 and optical sensors 303 has been removed from the coverage of the tragus 115, thus preventing light from being transmitted into the tragus 115. However, within a limited range of rotation of the earpiece 400, both the lower light source 301 and the optical sensor 303 are still covered by and in contact with the tragus 115. Therefore, light from the lower light source 301 can still enter the tragus 115 and be detected by the optical sensor 303.

[0045] Figure 6 The following situation is shown, where Figure 4 The earpiece 400 has been rotated clockwise, and the lower light source 301 in the row of light sources 301 and optical sensors 303 has fallen out of the cover of the tragus 115, thus preventing light from being transmitted into the tragus 115. However, within a limited range of rotation of the earpiece 400, both the higher light source 301 and the optical sensor 303 are still covered by and in contact with the tragus 115. Therefore, light from the higher light source 301 can enter the tragus 115 and be detected by the optical sensor 303.

[0046] In such Figure 7 shown Figure 4In variant 700 of the embodiment, two optical sensors 303 are used with the same light source 301, instead of two light sources 301 with the same optical sensor 303. The light source 301 is located at the center of the optical sensor-light source-optical sensor 303 column. However, if the user becomes negligent and the earpiece 200 rotates within the concha 117, exposing one of the optical sensors 303 so that it is no longer covered by the tragus 115, the distance between the optical sensor 303 and the light source 301 would allow the other optical sensor 303 to remain under the coverage of the tragus 115 along with the light source 301.

[0047] Earpieces 400 and 700 are suitable devices for negligent users because, although earpieces 400 and 700 can rotate in place within the concha 117 to an permissible extent, at least one sensor component—i.e., a light source 301 or an optical sensor 303—provided in additional or spare quantities may still be covered by the tragus 115, and the observation of the user's physiological data remains stable, continuous, and uninterrupted. In other words, earpieces 400 and 700 have at least one additional light source 301 or optical sensor 303 to provide a backup that allows earpiece 200 to be misaligned.

[0048] Although the accompanying drawings show earpieces 200, 400, and 700 for the left ear, those skilled in the art will understand that mirror-sized earpieces can be made for the right ear. To use earpieces 200, 400, and 700, the user simply inserts them into the concha 117 of their ear and rotates them until the tragus 115 correctly covers the entire optical sensor 303 and the light source. However, more preferably, the disc shape of earpieces 200, 400, and 700 is made such that both sides of the disc can fit into the concha 117 of both the right and left ears. In this way, production costs may be reduced, as only one mold is needed to produce earpieces 200, 400, and 700 for both the right and left concha 117.

[0049] exist Figure 4 and Figure 7 Further variations can be provided in both embodiments, wherein different frequencies of light can be used in the same earpieces 400 and 700. For example, in Figure 4In the device 400, two light sources 301 are located adjacent to an optical sensor 303, emitting light into the tragus 115. These two light sources 301 can emit light at different electromagnetic frequencies, such as red and infrared light. Since there is only one optical sensor, the two light sources 301 emit light in a compact, alternating manner, one after the other. The earpiece 400 includes a microcontroller capable of identifying when and which light source 301 is emitting light and accordingly attributing the readings of the optical sensor 303 to the correct light source 301. Because the light sources 301 switch very rapidly, the data readings for the two different electromagnetic frequencies are practically continuous. If the reading of the optical sensor 303 for any one electromagnetic frequency is significantly lower than the reading for the other, it means that the light source 301 has necessarily deviated from its position where it can emit light into the tragus 115.

[0050] Assuming the user maintains the correct positioning of the earpiece 400 and simultaneously uses two electromagnetic frequencies to monitor blood flow in the tragus 115, more information can be obtained compared to the case with only the pulse, such as the oxygen saturation in the blood, which requires measuring the difference between the absorption of red and infrared light. This technique is known and need not be detailed here.

[0051] Figure 7 The embodiment 700 can also be modified in a similar manner. Figure 7 The light source 301 can emit light within a multi-color range of different electromagnetic frequencies, such as a range including both red and infrared light, or simply a range of white light. Each of the two optical sensors 303 is equipped with a different filter, allowing the optical sensor 303 to detect different electromagnetic frequencies. It is not necessary for either the light source 301 or the optical sensor 303 to operate alternately, as both optical sensors 303 can operate simultaneously. If the reading of either optical sensor 303 is abnormal, such as if the amount of light detected is significantly higher than the reading of the other optical sensor 303, it may mean that the optical sensor 303 has deviated from the tragus 115 and is exposed to ambient light. In this case, the reading of the deviated optical sensor 303 is ignored, while the reading of the other optical sensor 303 can still be used to continue monitoring the user's pulse.

[0052] Preferably, earpieces 200, 400, and 700 include a gyroscope for sensing the orientation of earpieces 200, 400, and 700. If earpieces 200, 400, and 700 rotate significantly from their initial position from which a reasonable reading is displayed, earpieces 200, 400, and 700 emit an alarm, such as a faint beep, from their built-in acoustic devices to alert the user to check the orientation of earpieces 200, 400, and 700.

[0053] Figure 8The illustration shows an earpiece 800 having an antenna and a microphone housed in a rod 803 hanging from the body of the earpiece 800. As in the embodiment described above, the body of the earpiece 800 is adapted to reside within the concha 117 of the ear. The earpiece 800 includes a microphone (not shown), thus functioning similarly to the Macintosh's AirPods. TM It functions as an earphone in this way. The shape of the earphone body is simply to fit the concha 117, without any part that inserts into the ear canal. Therefore, since it is not possible to use the ear canal, such an earpiece 800 benefits from having a light source 301 and an optical sensor 303 configured to illuminate the tragus 115.

[0054] The earpiece 800 requires a microprocessor and memory for controlling the operation of the light source 301 and the optical sensor 303. Typically, the memory includes firmware for instructing the microprocessor's execution. To enable the earpiece 800 to transmit physiological data, it preferably includes a wireless transceiver and can communicate via technologies such as Bluetooth. TM Or send data using any known communication protocol such as Wi-Fi. Alternatively, such as Figure 8a As shown, the earpiece 800 has a cable 805 that can be connected to a suitable jack on the computing earpiece 800 that can collect data, such as a cable connector on a smartphone that can download data from the earpiece 800 for processing.

[0055] Figure 9 Another earpiece 900 is shown, in which the physiological detector is not an optical sensor as described above. Instead, electrodes are provided. Figure 9 Two negative electrodes 901 and one positive electrode 903 arranged in an array are shown, capable of being aligned with the tragus 115. These electrodes operate according to circuitry disposed within the earpiece 900 and may be part of an impedance monitor, temperature sensor, etc. The impedance monitor can be used to detect whether the earpiece 900 is in contact with the skin of the ear. An additional electrode of the same polarity is provided for backup. Therefore, in Figure 9 In this configuration, one of the negative electrodes 901 can be moved away from contact with the tragus 115, such as when the earpiece 900 is rotated counterclockwise when inserted into the left ear. Within permissible limits, the other negative electrode 901 remains in contact with the tragus 115, and together with the positive electrode 903, which is also in contact with the tragus 115, it reads physiological information by contacting the tragus 115. Despite the limited range of rotation of the earpiece 900, this provides a high probability that the earpiece 900 can continue to monitor the user's physiological condition.

[0056] Although Figure 9 The columns of negative-positive-negative electrodes 901 and 903 are shown, but the opposite case of columns with positive-negative-positive electrodes is also expected in this embodiment.

[0057] Figure 10 A further embodiment 1000 is shown, in which there are three pairs of light source-optical sensors. Any one pair can be rotated out of the range of interaction with the tragus 115, and at least one other pair is present within a limited range that can still interact with the tragus 115. This also provides continuous physiological monitoring of the user, since any pair can be moved to a position that does not come into contact with the tragus 115 without interrupting the continuity of physiological monitoring.

[0058] Figure 11 Another embodiment 1100 is shown, in which there are only two electrodes 1101, 1103. Each electrode is a metal contact line extending along at least a portion of the outer periphery of the disc-shaped earpiece 110. As shown, one electrode 1103 is placed closer to the inner side of the earpiece 1100, closer to the ear, while the other electrode 1101 is placed closer to the outer side of the earpiece 1100. Therefore, the two electrodes 1101, 1103 are parallel. The earpiece 1100 can rotate within the concha 117 without breaking the contact between the electrode and the tragus, as long as the rotation is within the length of the electrode. If the electrode is laid out along the entire outer periphery, even large rotations will not break the contact between the electrode and the tragus.

[0059] Figure 12 The illustration shows a gear-like edge on the lug 1200, rather than a smooth and continuous edge. Figure 12 This illustrates how the edge of the earpiece 1200, which contacts the tragus 115, can have discontinuous surface areas yet still provide continuous physiological monitoring as the earpiece 1200 rotates within the concha 117. Provided there are a sufficient number of discontinuous surfaces positioned sufficiently close to each other, and sensor components are disposed on each discontinuous surface, one discontinuous surface with sensor components can move away from contact with the tragus 115 while another discontinuous surface with sensor components remains in contact with the tragus 115. In this way, physiological monitoring of the user via contact with the tragus 115 is maintained despite movement of the earpiece 1200.

[0060] Therefore, the described embodiments include earpieces 200, 400, 700, 1000, 1100, and 1200, each having a shape for fitting into the concha 117 of a user's ear, and a surface for contacting the tragus 115 of the ear; and a physiological sensor disposed on the surface such that the physiological sensor can interact with the tragus 115. Preferably, the physiological sensor includes at least one light source 301 and at least one optical sensor 303.

[0061] While preferred embodiments of the invention have been described above, those skilled in the art will understand that many variations or changes can be made to the details of the design, construction, or operation without departing from the scope of the invention as claimed.

[0062] For example, while an optical sensor 303 is described in most embodiments, other detectors may alternatively be implemented in these embodiments. Any type and every type of sensor can be added to the device. For example, the device may also include a temperature sensor, a photodiode, a humidity sensor, and every other type of analytical sensor.

Claims

1. A wireless earpiece, The wireless earpiece has a shape for fitting into the concha of a user's ear. The wireless earpiece has a surface for contacting the tragus of the ear, the surface having an area exceeding the tragus; and Physiological sensors disposed on the surface enable them to interact with the tragus. The physiological sensor includes multiple sensor components for interacting with the tragus; and The plurality of sensor components are disposed at different positions in the region, such that when the user wears the device, the plurality of sensor components are aligned along the length of the tragus, and such that when the position of the wireless earpiece in the concha changes and a part of the region moves to a position where it is no longer in contact with the tragus, the other part of the region remains in contact with the tragus, and both the part and the other part of the region are provided with sensor components.

2. The wireless earpiece as claimed in claim 1, wherein... The plurality of sensor components include at least one light source and at least one optical sensor.

3. The wireless earpiece as claimed in claim 1, wherein the plurality of sensor components are a plurality of light sources.

4. The wireless earpiece as claimed in claim 3, further comprising: At least one optical sensor is disposed between two of the plurality of light sources arranged in a line, the line extending along the length of the tragus when worn by the user.

5. The wireless earpiece as claimed in claim 1, wherein... The multiple sensor components are multiple optical sensors.

6. The wireless earpiece of claim 5, further comprising: At least one light source is disposed between two of the plurality of optical sensors arranged in a line, the line extending along the length of the tragus when worn by the user.

7. The wireless earpiece as claimed in claim 1, wherein... The multiple sensor components are multiple electrodes of different polarities.

8. The wireless earpiece as claimed in claim 7, wherein The multiple electrodes are used to measure skin impedance.

9. The wireless earpiece as claimed in claim 7, wherein The multiple electrodes are used to measure electrocardiogram (ECG) signals.

10. The wireless earpiece as described in any of the preceding claims, further comprising: The speaker enables the wireless earpiece to be used as headphones.

11. A method for providing continuous physiological monitoring using a wearable wireless earpiece, the method comprising the steps of: A wireless earpiece is provided, which has multiple sensor components disposed at different positions on the wireless earpiece, wherein the multiple sensor components are aligned along the length of the tragus when worn by a user; Position the wireless earpiece into the user's ear such that at least one of the plurality of sensor components interacts with the tragus; The wireless earpiece is allowed to move such that at least one of the plurality of sensor components moves to a position where at least one of the plurality of sensor components cannot interact with the tragus, and at least another of the plurality of sensor components moves to a position where at least another of the plurality of sensor components can continue to interact with the tragus.

12. The method for providing continuous physiological monitoring using a wearable wireless earpiece as described in claim 11, wherein... The multiple sensor components are multiple optical sensors.

13. The method for providing continuous physiological monitoring using a wearable wireless earpiece as described in claim 11, wherein... The multiple sensor components are multiple light emitters.

14. The method for providing continuous physiological monitoring using a wearable wireless earpiece as described in claim 11, wherein... The multiple sensor components are multiple electrodes.

Images