Receiver and position estimation system for ingestible device

Abstract

A receiver (10A) that is mounted on a body surface comprises: a reception unit (11) that receives an ultrasonic wave signal transmitted from an ingestible device inside the body; a reception information measurement unit (12) that measures reception information including information regarding at least one of an elapsed time from a reference time to a time when the ultrasonic wave signal is received, a reception intensity of the ultrasonic wave signal, and a reception time difference of the ultrasonic wave signal; and a device position estimation unit (13) that estimates the position of the ingestible device inside the body on the basis of the reception information.

Description

Location estimation system for receivers and medication devices

[0001] This invention relates to a system for estimating the position of a receiver and a drug-administered device.

[0002] When measuring vital data using an inhalable in-vivo sensing device (Smartpill), it is important to identify the location where the measurement is being taken.

[0003] Non-patent document 1 describes a system that uses a highly efficient planar electromagnetic coil that encodes each spatial point with a different magnetic field strength to generate a three-dimensional magnetic field gradient within the field of view of the digestive tract, thereby enabling real-time, millimeter-level three-dimensional localization and tracking of wirelessly ingestible microdevices within the digestive tract of large animals.

[0004] S. Sharma et al. , “Location-aware ingestible microdevices for wireless monitoring of gastrointestinal dynamics”, Nature Electronics, 2023 March, Volume 6, Issue 3, p. 242-256

[0005] However, the system described in Non-Patent Document 1 requires the installation of a highly efficient planar electromagnetic coil to generate a magnetic field in order to locate the wirelessly ingestible microdevice. In other words, a dedicated device is required to locate the microdevice.

[0006] The present invention has been made to solve the above problems and aims to provide a receiver and a system for estimating the position of a drug-administered device within the body, without requiring a dedicated device for position estimation.

[0007] The receiver of the present invention is a receiver attached to the surface of the body and comprises: a receiving unit that receives an ultrasonic signal transmitted from a drug-taking device located inside the body; a receiving information measuring unit that measures received information including at least one piece of information: the elapsed time from a reference time to the time the ultrasonic signal was received, the received intensity of the ultrasonic signal, and the difference in the received time of the ultrasonic signal; and a device position estimation unit that estimates the position of the drug-taking device inside the body based on the received information.

[0008] The present invention provides a device position estimation system for a drug-administered device, comprising: a receiver attached to the body surface, having a receiving unit for receiving ultrasonic signals transmitted from a drug-administered device located inside the body; a receiving information measuring unit for measuring received information including at least one piece of information: the elapsed time from a reference time to the time the ultrasonic signal was received, the received intensity of the ultrasonic signal, and the difference in the received time of the ultrasonic signal; and a device position estimation unit for estimating the position of the drug-administered device inside the body based on the received information.

[0009] According to the present invention, it is possible to provide a receiver and a system for estimating the position of a drug-administered device that can determine the position of the drug-administered device within the body without requiring a dedicated device for position estimation.

[0010] Figure 1 is a block diagram illustrating an example of the configuration of the receiver in Embodiment 1. Figure 2 is a graph showing the relationship between the distance between the receiver and the drug delivery device and the detected voltage indicating the received signal strength. Figure 3 is a graph showing the relationship between the distance between the receiver and the drug delivery device and the received delay time. Figure 4 is a schematic diagram showing how the drug delivery device moves within the digestive tract. Figure 5 is a graph showing the results of a simulation of the change in the received delay time. Figure 6 is a schematic diagram showing an example of the receiver in Embodiment 1 being worn. Figure 7 is a schematic diagram showing an example of the receiver in Embodiment 5 being worn. Figure 8 is a graph showing the results of a simulation of the change in the received delay time in the two receiving units shown in Figure 7. Figure 9 is a graph showing the change in the sum of the received delay times shown in Figure 8. Figure 10 is a block diagram illustrating an example of the drug delivery device position estimation system in Embodiment 7.

[0011] The following describes the receiver and drug device position estimation system of the present invention. However, the present invention is not limited to the configuration described below, and may be modified as appropriate without altering the essence of the invention. Furthermore, a combination of several of the preferred configurations described below also constitutes the present invention.

[0012] The embodiments described below are illustrative, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments is possible. In the second embodiment and subsequent embodiments, descriptions of matters common to the first embodiment will be omitted, and the differences will be described mainly. In particular, similar effects and advantages due to similar configurations will not be mentioned sequentially for each embodiment.

[0013] In the following description, unless otherwise specified, each embodiment will simply be referred to as "the receiver of the present invention."

[0014] The drawings shown below are schematic representations, and their dimensions, aspect ratios, and scales may differ from those of the actual product.

[0015] [Embodiment 1] In a first embodiment, the present invention is a receiver that is attached to the surface of the body and comprises: a receiving unit that receives an ultrasonic signal transmitted from a drug-taking device located inside the body; a receiving information measuring unit that measures received information including at least one piece of information: the elapsed time from a reference time to the time the ultrasonic signal was received, the received intensity of the ultrasonic signal, and the difference in the time of reception of the ultrasonic signal; and a device position estimation unit that estimates the position of the drug-taking device inside the body based on the received information.

[0016] Figure 1 is a block diagram illustrating an example of the configuration of the receiver in Embodiment 1.

[0017] As shown in Figure 1, the receiver 10A includes a receiving unit 11, a received information measuring unit 12, and a device position estimation unit 13. The receiver 10A may also include a microcontroller (microcomputer), a storage unit, a transmitting unit (described later), a display unit, and a battery.

[0018] The receiving unit 11 receives ultrasonic signals emitted from the oral medication device located inside the body. By receiving ultrasonic signals from the oral medication device, the receiver 10A acquires biological information such as core body temperature and pH acquired by the oral medication device while inside the body.

[0019] The receiving unit 11 consists of an ultrasonic receiver that receives ultrasonic waves. The principle of ultrasonic wave reception by the ultrasonic receiver is not particularly limited, but it may include, for example, a piezoelectric element, and the piezoelectric element may generate a voltage when it receives ultrasonic waves. The piezoelectric element provided in the receiving unit 11 is also called a piezoelectric vibrator. As materials for the piezoelectric element, PZT (lead zirconate titanate), BT (barium titanate), KNN (potassium sodium niobate), etc. can be used.

[0020] The received information measurement unit 12 and the device position estimation unit 13 function by executing corresponding programs via a microcontroller. The microcontroller is a controller that controls each part of the receiver 10A and consists of a program for realizing various processes stored in the memory unit, and a CPU (Central Processing Unit) that executes the program.

[0021] The received information measuring unit 12 measures received information that includes at least one of the following pieces of information: the elapsed time from a reference time to the time the ultrasonic signal was received, the received intensity of the ultrasonic signal, and the difference in the time of reception of the ultrasonic signal. In other words, the received information measuring unit 12 may measure only one of the following pieces of information as received information: the elapsed time from a reference time to the time the ultrasonic signal was received, the received intensity of the ultrasonic signal, and the difference in the time of reception of the ultrasonic signal; it may measure any two of the following pieces of information; or it may measure all of the following pieces of information.

[0022] The received intensity of the ultrasonic signal (hereinafter also simply referred to as received intensity) can be measured, for example, as the magnitude of the voltage generated by the reception of the ultrasonic signal in the piezoelectric element of the receiving unit 11, i.e., the detected voltage of the piezoelectric element (voltage change due to displacement of the piezoelectric element, output voltage). The magnitude of this voltage can be obtained, for example, by detecting the detected voltage using a voltage detection circuit and amplifying it with a voltage amplification circuit. Alternatively, the difference between the positive and negative peaks (V p - p) of the sinusoidal output waveform of the voltage amplification circuit may be obtained as the detected voltage.

[0023] Furthermore, the signal received by the receiving unit 11 may contain noise signals in addition to the ultrasonic signal emitted from the drug administration device. Therefore, the detection voltage of the piezoelectric element detected as described above may be used with a voltage comparison circuit to determine whether it is an ultrasonic signal or a noise signal emitted from the drug administration device.

[0024] The difference in reception time of an ultrasonic signal (hereinafter also simply referred to as the reception time difference) is given by: reception time difference t = t ｂ - (t ａ +n × t ｓ ) is represented as t ｂ t is the time of reception of the ultrasonic signal. If the transmission time of the ultrasonic signal cannot be measured in the drug administration device, the transmission time of the received ultrasonic signal is also unknown in the receiver 10A. Therefore, it is difficult to directly calculate the reception delay time, which is the time required from the ultrasonic signal transmitted from the drug administration device until it is received by the receiver. However, the change in reception delay time can be shown by the change in the reception time difference t. ａ n is the reference time (time), which may be the time when the first ultrasound signal emitted from the medication device is received, or the time when the first ultrasound signal indicating that the medication device has moved from the stomach to the duodenum is received. n is the reference time t ａ This is the number of times an ultrasonic signal was transmitted after a certain point. Note that (n-1) may be used instead of n. ｓrepresents the transmission interval of an ultrasonic signal transmitted by an ingestion device (hereinafter also simply referred to as the transmission cycle), and the transmission of the ultrasonic signal is performed at a constant cycle. Said transmission cycle is preset, and according to said setting, when powered on, the ingestion device transmits ultrasonic signals at the constant cycle. t ｓ may be, for example, not less than 1 second and not more than 10 minutes. Said transmission cycle can be arbitrarily set according to the type of data to be measured and the position of the receiving unit 11. In addition, said transmission cycle is also stored in the receiver 10A and is used for calculating the reception time difference t.

[0025] Note that the first ultrasonic signal indicating that the ingestion device has moved from the stomach to the duodenum is preferably the first ultrasonic signal where the pH value has changed from acidic to neutral or alkaline, and specifically, is preferably the first ultrasonic signal where the pH value satisfies pH ≧ 6.

[0026] The elapsed time from a reference time to the time when an ultrasonic signal is received (hereinafter also simply referred to as elapsed time) indicates the time from the reference time to the time when each round of ultrasonic signal is received. The reference time in said elapsed time is the reference time t described in the explanation of the reception time difference ａ and may be said reference time t.

[0027] The device position estimating unit 13 estimates the in-vivo position of the ingestion device based on reception information. This makes it possible to specify the in-vivo position of the ingestion device without requiring a dedicated device for position estimation. More specifically, the receiver 10A can estimate the in-vivo position of the ingestion device only by detecting the elapsed time, reception intensity and / or reception time difference of the ultrasonic signal while acquiring biological information as an ultrasonic signal. That is, since it is only necessary to be able to transmit and receive ultrasonic signals for acquiring biological information, no dedicated device for estimating the in-vivo position of the ingestion device is required.

[0028] Furthermore, by estimating the position of the swallowing device within the body, the receiver 10A can estimate which part of the body the acquired biometric information is from. It can also estimate the movement speed of the swallowing device from its position within the body and the elapsed time, thus allowing for the estimation of intestinal activity. Additionally, by estimating the movement time (residence time) of the swallowing device in the rectum from its position within the body and the elapsed time, the state of bowel movements can be estimated.

[0029] The device position estimation unit 13 may estimate the position of the medication device within the body based on either the received signal strength or the received time difference from the received information.

[0030] Figure 2 is a graph showing the relationship between the distance between the receiver and the drug device and the detected voltage indicating the signal strength. Figure 3 is a graph showing the relationship between the distance between the receiver and the drug device and the reception delay time.

[0031] The intensity of ultrasound is I (W / m). ２ If P (W) is the total power emitted from the sound source and r (m) is the distance from the sound source, then the intensity of the ultrasound is I = P / 4πr ２ This relationship is expressed by the inverse square law. That is, the intensity of ultrasound decreases inversely proportional to the square of the distance. This is because as the distance from the sound source increases, the energy is dispersed over a wider area. Therefore, the received intensity of ultrasound emitted from the drug device also decreases as the distance between the receiver and the drug device increases, specifically, it decreases inversely proportional to the square of the distance between the receiver and the drug device. As a result, the received intensity decreases as the distance between the receiver and the drug device increases, and as shown in Figure 2, the detection voltage of the piezoelectric element also decreases as the distance between the receiver and the drug device increases. In other words, the received intensity increases or decreases as the distance between the receiver and the drug device increases or decreases.

[0032] The reception delay time is the time required for an ultrasonic signal transmitted from an ingestion device to be received by a receiver. The reception delay time increases as the required time increases when the distance between the receiver and the ingestion device becomes longer. Therefore, as shown in FIG. 3, the reception delay time increases as the distance between the receiver and the ingestion device becomes longer. When the distance between the receiver and the ingestion device increases or decreases, the reception delay time also increases or decreases. Further, the reception time difference t is proportional to the change in reception time t ｂ , and the reception time t ｂ changes in accordance with a change in the reception delay time. That is, when the reception delay time increases or decreases, the reception time difference also increases or decreases in accordance with the increase or decrease in the reception delay time.

[0033] Therefore, when the distance between the receiver and the ingestion device changes, the reception intensity and the reception time difference also change in accordance with the change.

[0034] FIG. 4 is a diagram schematically illustrating how an ingestion device moves inside the digestive tract. FIG. 5 is a graph showing results of simulating a transition of the reception delay time. The graph shown in FIG. 5 shows results of simulating the transition of the reception delay time in a reception unit disposed at a position 1 cm below the navel. In the simulation of the transition of the reception delay time, the passage time of the ingestion device through each organ is calculated based on the average time the ingestion device stays in each organ, the distance between the reception unit and the ingestion device during each passage time is calculated based on internal arrangement information, and the reception delay time for each passage time is calculated.

[0035] The time for the ingestion device to reach the stomach from the mouth is approximately 10 seconds to 1 minute as a guideline. Normally, after being swallowed, the ingestion device passes through the esophagus in several seconds to several tens of seconds and reaches the stomach.

[0036] Further, the gastric residence time (passage time from the stomach to the duodenum) of the ingestion device is generally about 30 minutes to 2 hours, and is several hours in long cases. The gastric residence time of the ingestion device particularly varies greatly. The ingestion device is sent to the duodenum by the movement of the stomach and the opening and closing of the pyloric sphincter. Drugs that promote gastric emptying (e.g., prokinetics, etc.) may also be used in some cases.

[0037] Further, the approximate transit time of an administration device from the duodenum to the small intestine (jejunum, ileum) is about 2 to 4 hours. Transit from the duodenum to the entire small intestine (jejunum, ileum) is relatively rapid.

[0038] Further, the colonic transit time of an administration device is, for example, about 10 to 24 hours; it is about 6 hours even for people with fast transit, and about 48 hours for people with slow transit.

[0039] In the calculation of transit time for simulating the transition of reception delay time, the average retention time of the administration device in each of the above organs was calculated respectively, and used as "the average retention time of the administration device retained in each organ".

[0040] Further, the distances from the navel to the stomach, duodenum, jejunum, ileum, cecum, the entrance of the ascending colon, the entrance of the transverse colon, the entrance of the descending colon, the rectum, and the anus are, for example, as follows. Stomach: about 15 to 20 cm; Duodenum: about 5 to 10 cm; Jejunum: about 5 to 15 cm; Ileum: about 10 to 20 cm; Cecum: about 20 to 30 cm; Entrance of ascending colon: about 25 to 30 cm; Entrance of transverse colon: about 15 to 20 cm; Entrance of descending colon: about 15 to 20 cm; Rectum: about 20 to 30 cm; Anus: about 35 to 45 cm

[0041] In the calculation of the distance between the receiving unit and the administration device for simulating the transition of reception delay time, the average value of the above distances from the navel to each organ was calculated respectively, and used as "internal organ arrangement information".

[0042] Note that the reception time difference exhibits a transition similar to the transition of the reception delay time shown in FIG. 5 and the like. Further, as the distance between the receiver and the administration device increases, the reception time difference increases in proportion to the distance, while the reception intensity decreases inversely proportional to the square of the distance. Therefore, the reception intensity changes in an opposite manner to the reception time difference. Accordingly, it is considered that although the direction of the transition of the reception intensity is opposite to that of the transition of the reception time difference (the transition of the reception delay time shown in FIG. 5 and the like), the timing (time point) at which increase and decrease switch is the same.

[0043] As shown in Figure 4, the administration device 20 moves sequentially from the stomach through the intestines (duodenum → jejunum → ileum → large intestine). Therefore, the reception time difference changes according to the elapsed time (or the number of times the ultrasonic signal is received), as shown in Figure 5, and also changes according to the structure (shape) and arrangement (position) of each digestive organ, and it is thought that there is a certain rule (regularity) in how it changes. Because of this regularity, the device position estimation unit 13 can estimate the organ in which the administration device 20 is located and / or its position within that organ based on the change in the reception time difference, which changes according to the elapsed time (or the number of times the ultrasonic signal is received). Furthermore, although the case based on the change in reception time difference has been explained here, the same can be said for the case based on the change in reception intensity.

[0044] Furthermore, after swallowing, the drug delivery device first resides in the stomach. Therefore, the time difference in reception and the changes in reception intensity can be observed starting from the time spent in the stomach. When observing the changes starting from the time spent in the stomach, the time difference in reception and other parameters hardly change during the time the device is in the stomach. However, characteristic changes occur in the time difference in reception and other parameters when the drug delivery device moves to the small intestine or large intestine, making it easier to estimate the location of the drug delivery device.

[0045] Furthermore, by estimating the location of the drug device based on the difference in reception time and reception intensity, the degree of intestinal activity can be estimated from the change in the length of time the drug device is estimated to be in the small or large intestine. In addition, the degree of constipation or bowel movement can be estimated from the length of time the drug device is estimated to be in the large intestine.

[0046] The position estimation of the drug administration device 20 based on the changes in signal strength or reception time difference may be performed sequentially in real time, or it may be performed retrospectively after all the data on signal strength or reception time difference has been detected.

[0047] Furthermore, since the structure of internal organs does not change significantly depending on factors such as age, sex, and body type, it is thought that the way in which the reception intensity or reception time difference changes does not change significantly depending on the above conditions. In addition, especially in adults, it is thought that there is little change in the structure of internal organs due to factors such as sex and body type.

[0048] Furthermore, the device position estimation unit 13 may estimate the position of the drug device within the body based only on the elapsed time from the received information. This allows, for example, the system to estimate how far the drug device has moved from a reference position (the position where the drug device was located at a reference time, for example, the entrance to the duodenum) based on the elapsed time, and to estimate the position of the drug device within the body. More specifically, for example, the system may calculate the estimated distance traveled by the drug device from the reference position based on the elapsed time and the average speed at which food moves through the digestive tract, and then estimate the position of the drug device within the body based on the calculated estimated distance traveled and the average position information of each digestive organ (information indicating the average distance from the reference position to each digestive organ).

[0049] Alternatively, the location of the drug delivery device at a given time interval may be estimated based on the elapsed time, the average time it takes for the drug delivery device to move through each organ, and the average positional information of each digestive organ. As the average time it takes for the drug delivery device to move through each organ, information such as the average time the drug delivery device stays in each organ, which was used in the simulation of the progression of the reception delay time described above, can be used.

[0050] Furthermore, the device position estimation unit 13 may estimate the position of the drug device within the body based only on the elapsed time and received intensity from the received information. By measuring the received intensity, the distance between the receiver and the drug device can be estimated from the received intensity based on the correspondence between the received intensity and the distance between the receiver and the drug device. When estimating the position of the drug device based only on elapsed time, it is expected to be affected by the amount and quality of food eaten, changes in intestinal activity that may occur due to physical condition, and the state of the intestines such as the presence or absence of deposits due to constipation or tumors. Therefore, by referring to information related to the ultrasonic signal emitted from the drug device, such as received intensity, in addition to elapsed time, it becomes possible to estimate the position of the drug device more accurately. Thus, by estimating the position of the drug device based on received intensity in addition to elapsed time, the accuracy of estimating the position of the drug device is improved compared to when it is based only on elapsed time.

[0051] Furthermore, the device position estimation unit 13 may estimate the position of the drug administration device based only on the received signal strength and the received time difference from the received information, or it may be based on either the received signal strength or the received time difference and the elapsed time, or it may be based on all of the received signal strength, the received time difference, and the elapsed time.

[0052] In particular, the received signal strength is susceptible to errors because it is affected by scattering, reflection, and absorption of ultrasound signals by substances in the intestines, as well as body fat, muscles, organs, etc. Therefore, by considering not only the received signal strength but also the reception time difference and / or elapsed time, it becomes possible to estimate the location of the drug administration device more accurately.

[0053] Furthermore, by preparing reference data that shows the average trends of reception intensity and reception time difference, the device position estimation unit 13 can estimate the position of the drug device based on the reception intensity and / or reception time difference and the corresponding reference data. By using this reference data, it becomes possible to detect errors in reception intensity and reception time difference due to the user's condition, and by correcting the reception intensity and / or reception time difference while referring to this error information, a more accurate position of the drug device can be estimated.

[0054] Also, any time t ｎ At time t ｎ Time t after a predetermined time (e.g., the interval between ultrasonic signal transmissions) ｎ＋１ The device position is predicted using a Kalman filter, and the device position estimation unit 13 determines the position of the medication device at time t ｎ＋１ This may be compared with the estimated location of the medication device.

[0055] Figure 6 is a schematic diagram showing an example of the receiver of Embodiment 1 installed.

[0056] As shown in Figure 6, the receiver 10A is attached to the body surface, specifically, to the body surface of the user, such as the torso, using a fastener such as a belt. Ultrasonic signals are reflected at the interface between the body and the air and hardly leak into the air, propagating only within the body. By attaching the receiver 10A to the body surface, the ultrasonic signals emitted from the drug device can be received by the receiver 10A.

[0057] The receiver 10A is attached, for example, so as to be in direct contact with the body surface, or so as to be in contact with the body surface via an intermediary such as a gel.

[0058] In the receiver of the present invention, one or more receiving units may be provided. As shown in Figure 6, only one receiving unit 11 may be provided, or two or more may be provided, as in the receiver of Embodiment 5 described later.

[0059] When only one receiving unit 11 is provided, the receiver feels lighter when worn. Therefore, from the viewpoint of reducing the burden of wearing the receiver, it is preferable that only one receiving unit 11 is provided.

[0060] The time variation of the received signal strength and the difference in reception time is affected by the position of the receiving unit 11. For example, if the receiving unit 11 is positioned far from the center of the arrangement of the small and large intestines, it is expected that the received signal strength of the ultrasonic signal emitted from the drug delivery device, which is far from the receiving unit 11, will be weakened. Therefore, from the viewpoint of improving the accuracy of estimating the position of the drug delivery device, if only one receiving unit 11 is provided, it is preferable to mount the receiver so that the receiving unit 11 is located near the center of the arrangement of the small and large intestines, for example, near the navel as shown in Figure 6.

[0061] [Embodiment 2] In the receiver of Embodiment 2 of the present invention, the device position estimation unit 13 estimates the position of the drug device within the body based on three-dimensional information of the internal organs, in addition to the received information. This improves the accuracy of estimating the position of the drug device.

[0062] The three-dimensional information of the internal organs is information (internal body map information) that shows the three-dimensional position and structure of each organ, and is, for example, information obtained from three-dimensional images obtained by MRI. The digestive organs are preferred as internal organs, and may also be the small intestine (duodenum, ileum, jejunum) and the large intestine (cecum, ascending colon, transverse colon, descending colon, sigmoid colon, rectum). Furthermore, the three-dimensional information of the internal organs may be an average of the three-dimensional information of the internal organs of a typical human, but it is preferable that it be the three-dimensional information of the internal organs of the person taking the drug device.

[0063] In addition to the received information, a method for estimating the position of the drug delivery device based on three-dimensional information of the internal organs may be used, for example, by referring to reference data based on three-dimensional information of the internal organs and correcting the estimated position based on the received information. This reference data may be data obtained by simulating the changes in received intensity and the difference in received time over time (or the number of times the ultrasound signal is received) based on three-dimensional information of the internal organs.

[0064] [Embodiment 3] In the receiver of Embodiment 3 of the present invention, the device position estimation unit 13 estimates the position of the drug device within the body using received information obtained by using the drug device multiple times, in addition to the received information. That is, in addition to the received information based on the ultrasonic signal received from the drug device of interest, which is the drug device whose position within the body is about to be estimated, the position of the drug device of interest is estimated using (learned) the received information based on the ultrasonic signals received from each drug device that has been taken at least once before the drug device of interest was taken. This improves the accuracy of drug device position estimation.

[0065] In addition to received data, a method for estimating the position of a drug administration device using received data obtained from multiple uses of the drug administration device may be used. For example, the estimated position based on received data for the device of interest may be corrected by referring to reference data based on received data obtained from multiple uses. More specifically, for example, when using received data obtained from two uses of the drug administration device, first, the difference at each time point between the received data obtained from the second use and the received data obtained from the first use is calculated. Then, this difference is used as a correction value to create predicted data for the received data in the third use, and the created predicted data is referred to as reference data to correct the received data for the device of interest in the third use. Furthermore, the difference between the received data obtained from the third use and the received data obtained from the first and second uses is calculated, and new predicted data is created using this difference. In this way, the accuracy of the predicted data can be improved in accordance with the number of times the drug administration device is used. In addition, the accuracy of the predicted data can be further improved by incorporating data such as the user's diet, posture, and heart rate in addition to the received data obtained from multiple uses of the drug administration device, and further improving the accuracy of the received data for the device of interest.

[0066] [Embodiment 4] In the receiver of Embodiment 4 of the present invention, the device position estimation unit 13 detects that the drug administration device has moved from the stomach to the duodenum based on the detection result of the pH sensor mounted on the drug administration device, and estimates the position of the drug administration device within the body based on the detection time. This makes it possible to more accurately determine the movement to the duodenum compared to determining it from the way in which the reception intensity changes (slope) or the elapsed time, thereby improving the accuracy of estimating the position of the drug administration device.

[0067] When the medication device moves from the stomach to the duodenum, the surrounding environment changes from acidic to neutral or alkaline. As a result, the pH value detected by the pH sensor on the medication device increases as the device moves from the stomach to the duodenum, becoming pH ≥ 6. The receiver can detect that the medication device has moved from the stomach to the duodenum because the acquired pH value is pH ≥ 6.

[0068] Furthermore, the detection time indicating that the drug administration device has moved from the stomach to the duodenum may be defined as the time when the first ultrasonic signal is received when the pH value exceeds a predetermined value, for example, pH ≥ 6.

[0069] The detection time indicating that the medication device has moved from the stomach to the duodenum is used to calculate the reception time difference t. ａ It can be used as such, or as a reference time for elapsed time.

[0070] [Embodiment 5] Figure 7 is a schematic diagram showing an example of the receiver of Embodiment 5 in a mounted state.

[0071] In the receiver 10B of this embodiment, as shown in Figure 7, there are two or more receiving units 11. This allows the position of the drug device inside the body to be estimated based on the received ultrasonic signal information received by the two or more receiving units 11, thereby improving the accuracy of position estimation of the drug device. Specifically, in the receiver 10B, the received information measurement unit measures the received ultrasonic signal information from each of the two or more receiving units 11, and the device position estimation unit estimates the position of the drug device inside the body based on the measured received information from each receiving unit 11.

[0072] The receiver 10B shown in Figure 7 is provided with two receiving units 11, receiving units 11a and 11b. When two receiving units 11 are provided in this way, it is preferable that each receiving unit 11 is provided on the front side of the body, symmetrically with respect to the center of the body (for example, near the navel), as shown in Figure 7. When three receiving units 11 are provided, it is preferable that two receiving units be provided on the front side of the body, symmetrically with respect to the center of the body (for example, near the navel), and one receiving unit be provided on the back side of the body, near the center of the body (for example, near the opposite side of the navel). Furthermore, as shown in Figure 7, it is preferable that each receiving unit 11 is provided far apart from each other, and it is preferable that the distance between each receiving unit 11 is greater than the distance between them.

[0073] Figure 8 is a graph showing the results of a simulation of the changes in reception delay time at the two receiving units shown in Figure 7. Figure 9 is a graph showing the changes in the sum of reception delay times shown in Figure 8. In Figure 8, the upper graph shows the results of a simulation of the changes in reception delay time at the receiving unit (receiving unit 11a in Figure 7) installed 12 cm to the right of the navel, and the lower graph shows the results of a simulation of the changes in reception delay time at the receiving unit (receiving unit 11b in Figure 7) installed 12 cm to the left of the navel. Since the reception time difference shows a similar change to the changes in reception delay time, the reception delay times shown in Figures 8 and 9 will be treated as equivalent to the reception time difference in the following explanation.

[0074] As shown in Figure 8, the reception delay time indicates that at times when the reception time difference between one of the receiving units 11a and 11b is smaller, that receiving unit is closer to the drug administration device than the other receiving unit. Furthermore, at times when the reception time difference between the two receiving units 11 is equal, it can be seen that the drug administration device is located at an equidistant position from both receiving unit 11a and receiving unit 11b.

[0075] Furthermore, as shown in the sum of reception delay times in Figure 9, the minimum point in the sum of reception time differences of each receiving unit 11 indicates that the medication device is located on the line segment connecting both receiving units 11a and 11b. Therefore, from the sum of reception time differences of each receiving unit 11, it can be determined that the medication device moved upward or downward relative to the receiving units 11a and 11b before and after the minimum point.

[0076] In other words, when two or more receiving units 11 are provided, as in the receiver 10B shown in Figure 7, these things can be determined using the difference in reception time between each receiving unit 11, thus improving the accuracy of estimating the position of the drug administration device compared to when only one receiving unit 11 is provided. Furthermore, although we have explained the case based on the difference in reception time, the same can be said for the case based on reception intensity.

[0077] In this embodiment, the receiver 10B may further estimate the position of the drug device within the body using three-dimensional information of the internal organs, as in the receiver of Embodiment 2 of the present invention. Alternatively, in this embodiment, the receiver 10B may estimate the position of the drug device within the body based on the detection time when the drug device moves from the stomach to the duodenum, as in the receiver of Embodiment 4 of the present invention.

[0078] Furthermore, by positioning the receiving units 11a and 11b along the path in which the drug administration device moves, the time the drug administration device remains along that path can be measured based on the duration of the period during which the sum of the reception time differences of each receiving unit 11 is at its minimum. Therefore, if the receiving units 11a and 11b are positioned along a straight section of the small or large intestine, the activity level of the intestines can be estimated, and if they are positioned along a straight section of the large intestine (especially the rectum), the state of bowel movements can be estimated.

[0079] [Embodiment 6] The receivers of Embodiments 1 to 5 of the present invention may be combined with a drug-taking device 20 that transmits biological information acquired in the body as an ultrasonic signal, as shown in Figure 1, to constitute a drug-taking device position estimation system.

[0080] The administration device 20 digitally processes the acquired analog biological information and transmits it as an ultrasonic signal at regular intervals. The biological information includes, for example, core body temperature and pH. The predetermined interval may be, for example, 1 second or more and 10 minutes or less, for example, 10 seconds or 1 minute. This interval can be arbitrarily set according to the type of data to be measured and the position of the receiving unit 11. The administration device 20 is also equipped with a pH sensor for detecting the pH value. The administration device 20 may also include a piezoelectric element, a battery, a biological information acquisition unit, an A / D converter, a storage unit, and a control unit, which will be described later. The pH sensor may also be included in the biological information acquisition unit. The biological information acquisition unit may include a temperature sensor (e.g., a thermistor) for detecting core body temperature.

[0081] [Embodiment 7] In a second embodiment, the present invention is a system for estimating the position of a drug device, comprising: a receiver attached to the surface of the body, having a receiving unit for receiving ultrasonic signals transmitted from a drug device located inside the body; a receiving information measuring unit for measuring received information including at least one piece of information: the elapsed time from a reference time to the time the ultrasonic signal was received, the received intensity of the ultrasonic signal, and the difference in the time of reception of the ultrasonic signal; and a device position estimation unit for estimating the position of the drug device inside the body based on the received information.

[0082] Figure 10 is a block diagram showing an example of a location estimation system for a drug administration device according to Embodiment 7.

[0083] As shown in Figure 10, the drug device position estimation system 100 comprises a receiver 110, a received information measurement unit 112, and a device position estimation unit 113. The received information measurement unit 112 may be included in the receiver 110 as shown in Figure 10, or it may be included in the processing unit 130. The device position estimation unit 113 may also be included in the processing unit 130 as shown in Figure 10. The processing unit 130 may be a mobile terminal such as a PC or smartphone, or a part of its functions (for example, the device position estimation unit 113) may be executed on a cloud server. That is, the device position estimation unit 113 may function on a PC or mobile terminal, or it may transfer received information from a PC or mobile terminal to a cloud server and function on the cloud server.

[0084] The receiver 110 receives ultrasonic signals transmitted from the drug administration device, acquires information from the drug administration device, measures the received information related to the ultrasonic signals, and transmits each piece of information to the processing unit 130. The receiver 110 is attached to the surface of the body. The receiver 110 may be the same as the receivers 10A and 10B described in the above embodiment.

[0085] The receiver 110 includes, for example, a receiving unit 111, a received information measuring unit 112, a transmitting unit 114, a battery 116, and a display unit 115. The receiver 110 may also include a microcontroller (microcomputer) and a storage unit.

[0086] The received information measurement unit 112 functions by executing a corresponding program via a microcontroller. The microcontroller is a controller that controls various parts of the receiver 110 and consists of a program for realizing various processes stored in the memory unit, and a CPU (Central Processing Unit) that executes the said program.

[0087] The receiving unit 111 receives ultrasonic signals transmitted from an intravenous drug device, and may be the same as the receiving unit in the receivers of embodiments 1 to 6 described above.

[0088] The receiving unit 111 may be provided in units of one or more. Also, when the device position estimation unit 113 is to be used in the processing unit 130, two or more receivers, each having a receiving unit, may be installed separately.

[0089] The received information measuring unit 112 measures received information that includes at least one piece of information: the elapsed time from a reference time when the ultrasonic signal was received, the received intensity of the ultrasonic signal, and the difference in the received time of the ultrasonic signal. It may function similarly to the received information measuring unit in the receivers of embodiments 1 to 6 described above.

[0090] The transmitting unit 114 transmits information acquired from the drug administration device and measured received information to the processing unit 130 via wireless communication. Wireless communication can be, for example, a data communication line using mobile phone radio waves, an internet line, Bluetooth®, etc. However, communication between the transmitting unit 114 and the processing unit 130 is not limited to wireless communication, and may also be conducted via wired connections such as USB cable connection, Ethernet cable connection, or serial cable connection.

[0091] The battery 116 supplies power to various parts of the receiver 110 and may be a rechargeable secondary battery. The specific type of battery 116 is not particularly limited.

[0092] The display unit 115 is configured to display information acquired from, for example, a medication device. Examples of the display unit 115 include a liquid crystal display.

[0093] The processing unit 130 acquires information transmitted from the transmitter 114 of the receiver 110, i.e., information from the drug administration device, and received information. Based on the acquired information, the processing unit 130 performs various data processing and data management. Specifically, for example, it manages and analyzes biological information acquired from the drug administration device, manages medications taken together with the drug administration device, and estimates the position of the drug administration device within the body.

[0094] The processing unit 130 includes, for example, a device position estimation unit 113.

[0095] The device position estimation unit 113 estimates the position of the drug device within the body based on the received information, and may function similarly to the device position estimation unit in the receivers of embodiments 1 to 6 described above.

[0096] For example, the device position estimation unit 113 may estimate the position of the drug device within the body based on three-dimensional information of the internal organs, in addition to the received information, similar to the receiver in Embodiment 2 of the present invention.

[0097] Furthermore, the device position estimation unit 113 may estimate the position of the drug device within the body using received information obtained by using the drug device multiple times, in addition to the received information, similar to the receiver in Embodiment 3 of the present invention.

[0098] Furthermore, the device position estimation unit 113 may, similar to the receiver in Embodiment 4 of the present invention, detect that the drug administration device has moved from the stomach to the duodenum based on the detection result of the pH sensor mounted on the drug administration device, and estimate the position of the drug administration device within the body based on the detection time.

[0099] [Embodiment 8] The position estimation system 100 for a drug administration device according to Embodiment 8 of the present invention further comprises a drug administration device 120 that transmits biological information acquired in the body as an ultrasonic signal, as shown in Figure 10.

[0100] The administration device 120 includes, for example, a piezoelectric element 124, a battery 126, a biometric information acquisition unit 121, and an A / D converter 123. The administration device 120 also includes a control unit 122 that controls the timing of acquiring biometric information, digitally processes the acquired analog biometric information, and transmits it to the receiving unit of the receiver 110 at regular intervals. In other words, the administration device 120 acquires and transmits biometric information at regular intervals. The regular interval may be, for example, 1 second or more and 10 minutes or less, for example, 10 seconds or 1 minute. This interval can be arbitrarily set according to the type of data to be measured and the position of the receiving unit 111. The biometric information acquisition unit 121 also includes sensors such as a temperature sensor for detecting core body temperature and a pH sensor for detecting pH value. The temperature sensor may include, for example, a thermistor.

[0101] The drug administration device 120 may also include a memory unit 125, for example, biological information acquired by the biological information acquisition unit 121 may be stored in the memory unit 125.

[0102] The drug administration device location estimation system 100 confirms, for example, whether the patient has taken the prescribed medication by the following method.

[0103] The drug administration device 120 is configured to automatically turn on when removed from its sealed container, and once powered on, the drug administration device 120 continuously emits an ultrasonic signal of a constant frequency from the piezoelectric element 124.

[0104] Simultaneously, the receiver 110 continues to receive the ultrasonic signal emitted from the drug administration device 120. When the drug administration device 120 is taken by the patient along with the medication, the frequency of the ultrasonic signal received by the receiver 110 changes as the drug administration device 120 enters the body. By detecting this change in frequency, it is possible to detect that the drug has been taken along with the drug administration device 120. This time may be used as a reference time for calculating the reception time difference, etc.

[0105] When the receiver 110 detects that the drug and the drug administration device 120 have been taken, it transmits information to the processing device 130 indicating this, and the processing device 130, upon receiving this information, manages whether the drug has been taken, the time of administration, etc. In addition, the received information measuring unit 112 of the receiver 110 transmits received information to the processing device 130, which includes at least one piece of information such as elapsed time, received signal strength, and received time difference, and the device position estimation unit 113 of the processing device 130, upon receiving this information, estimates the position of the drug administration device inside the body based on the received information.

[0106] 10A, 10B, 110 Receivers 11, 11a, 11b, 111 Receiving Units 12, 112 Received Information Measurement Units 13, 113 Device Position Estimation Units 20, 120 Medication Device 100 Medication Device Position Estimation System 114 Transmitter 115 Display Unit 116, 126 Battery 121 Biometric Information Acquisition Unit 122 Control Unit 123 A / D Converter 124 Piezoelectric Element 125 Storage Unit 130 Processing Unit

Claims

1. A receiver that is attached to the surface of the body, comprising: a receiving unit that receives an ultrasonic signal transmitted from a drug-taking device located inside the body; a receiving information measuring unit that measures received information including at least one piece of information: the elapsed time from a reference time to the time the ultrasonic signal was received, the received intensity of the ultrasonic signal, and the difference in the time of reception of the ultrasonic signal; and a device position estimation unit that estimates the position of the drug-taking device inside the body based on the received information.

2. The receiver according to claim 1, wherein two or more receiving units are provided.

3. The receiver according to claim 1 or 2, wherein the device position estimation unit estimates the position of the drug-taking device within the body based on three-dimensional information of the internal organs, in addition to the received information.

4. The receiver according to any one of claims 1 to 3, wherein the device position estimation unit estimates the position of the drug device within the body using, in addition to the received information, received information obtained by using the drug device multiple times.

5. The receiver according to any one of claims 1 to 4, wherein the device position estimation unit detects that the drug-taking device has moved from the stomach to the duodenum based on the detection result of a pH sensor mounted on the drug-taking device, and estimates the position of the drug-taking device within the body based on the detection time.

6. A system for estimating the position of a drug administration device, comprising: a receiver according to any one of claims 1 to 5; and a drug administration device that transmits biological information acquired inside the body as an ultrasonic signal.

7. A system for estimating the position of a drug device, comprising: a receiver attached to the surface of the body, having a receiving unit for receiving ultrasonic signals transmitted from a drug device located inside the body; a receiving information measuring unit for measuring received information including at least one piece of information: the elapsed time from a reference time to the time the ultrasonic signal was received, the received intensity of the ultrasonic signal, and the difference in the time of reception of the ultrasonic signal; and a device position estimation unit for estimating the position of the drug device inside the body based on the received information.

8. The location estimation system for a drug administration device according to claim 7, wherein two or more receiving units are provided.

9. The device position estimation system according to claim 7 or 8, wherein the device position estimation unit estimates the position of the drug device within the body based on three-dimensional information of the internal organs in addition to the received information.

10. The device position estimation system according to any one of claims 7 to 9, wherein the device position estimation unit estimates the position of the drug device within the body using received information obtained by using the drug device multiple times, in addition to the received information.

11. The device position estimation unit detects that the drug device has moved from the stomach to the duodenum based on the detection result of a pH sensor mounted on the drug device, and estimates the position of the drug device within the body based on the detection time, according to any one of claims 7 to 10.

12. A location estimation system for a drug device according to any one of claims 7 to 11, further comprising a drug device that transmits biological information acquired within the body as an ultrasonic signal.

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