Intrauterine monitoring and contraception system

Abstract

An intrauterine monitoring system is described. The system has an intrauterine device shaped and sized to be implanted into the uterus, and a receiving device. An intrauterine device is used to measure conditions within the uterus to generate sensor data and to act as a contraceptive device to prevent pregnancy. The receiving device is used for wirelessly receiving sensor data generated by the implantable sensor device of the intrauterine device.

Description

Technical Field

[0001] The present invention relates to an intrauterine monitoring and contraceptive system. Embodiments of the present invention relate to a system for long-term, real-time, in vivo measurement of biophysical parameters and contraceptive function in the human uterus. Background Art

[0002] Contraceptive intrauterine devices (IUDs) are implantable contraceptive devices. Currently, contraceptive IUDs chemically or physically disrupt the uterus to prevent implantation of a fertilized egg. They are effective contraceptive devices because they do not rely on the patient to perform tasks (such as taking oral contraceptives every day), are long-term (>5 years), and are non-permanent. Contraceptive IUDs are designed to be implanted in the uterus for months to years, during which time uterine function and the intrauterine environment (i.e., biophysical parameters such as temperature, dissolved oxygen concentration, pH, glucose, etc.) may change, for example in response to hormonal changes as the patient ages. Abnormal changes in the intrauterine environment may serve as early indicators of disease, such as endometrial cancer or conditions such as endometriosis. However, current contraceptive IUDs do not provide long-term in vivo monitoring to detect these changes in the uterus.

[0003] The present invention is intended to address these limitations. Summary of the invention

[0004] According to one aspect of the present invention, there is provided an intrauterine contraceptive system, comprising:

[0005] Intrauterine devices, which are shaped and sized to be implanted in the uterus; and

[0006] receiving device,

[0007] Among them, the intrauterine device is used to measure conditions in the uterus to generate sensor data and is used as a contraceptive device to prevent pregnancy, and

[0008] The receiving device is used to wirelessly receive sensor data generated by the intrauterine contraceptive device.

[0009] In this way, the IUD can monitor and collect data about the intrauterine environment over long periods of time. The IUD can be kept small and simple, requiring only the mechanical and electronic structures required to take the sensor measurements and transmit them to a receiving device, and a device to chemically or physically disrupt the intrauterine environment to prevent implantation of a fertilized egg.

[0010] Preferably, the receiving device is operable to wirelessly charge the IUD. In this way, a battery may not be required in the IUD, or its size may be minimised, making it smaller and avoiding potential problems associated with intrauterine battery leakage.

[0011] Preferably, the shape of the IUD is designed to be anchored in the uterus. This can prevent the IUD from moving in the uterus to ensure effective contraceptive function and can help to carry out effective wireless communication with the receiving device.

[0012] Preferably, the IUD is shaped to contact at least a portion of the endometrium in the uterus.

[0013] Preferably, at least a portion of the IUD that contacts the endometrium disrupts the growth of the endometrium, thereby interfering with the implantation of a fertilized egg and preventing pregnancy.

[0014] Preferably, the IUD releases chemicals into the uterus to disrupt the intrauterine environment.

[0015] Preferably, the chemical is located in or as a coating of a portion of the IUD, or is located in or as a portion of the IUD.

[0016] Preferably, the chemical is hormonal, such as progesterone or estrogen, or non-hormonal, such as copper.

[0017] Preferably, wireless charging can be performed using electromagnetic field coupled wireless energy transfer. The receiving device may include an antenna, a transceiver circuit, and a power source, and the intrauterine device may include an antenna, a charging circuit, and a controller. The receiving device is operable to transfer power from the antenna of the receiving device to the antenna of the intrauterine device by electromagnetic coupling. The charging circuit uses the power to store power to operate the sensor of the intrauterine device and transmit the sensor data to the receiving device.

[0018] Preferably, the intrauterine device includes a capacitor or a rechargeable battery, and the charging circuit can store electricity by charging the capacitor or the rechargeable battery.

[0019] The power source may be a rechargeable battery.

[0020] Preferably, the receiving device has a controller and a primary coil for wirelessly communicating with the intrauterine device, and the receiving device is operable to wirelessly charge the intrauterine device through inductive coupling between the primary coil and the secondary coil; wherein:

[0021] The quality factor of the primary coil is controllable;

[0022] The controller is operable to control the quality factor of the primary coil to be higher when the receiving device is wirelessly charging the IUD than when the receiving device is receiving sensor data from the IUD; and

[0023] The receiving device drives the primary coil to operate at a frequency of the order of 100 kHz.

[0024] Since the quality factor is controllable, the same coil can be used both for using the coil in a (relatively) high quality factor mode for efficient power transfer (wireless charging) and for using the coil in a (relatively) low quality factor mode for reliable data communications.

[0025] The quality factor can be controlled by modifying the resistance associated with the primary coil. For example, a damping resistor can be connected or disconnected in series with the primary coil.

[0026] The quality factor of the primary coil can be selected between a number of different levels. In a simple case, this can be two levels - a high level for wireless charging and a low level for receiving and / or transmitting data. In a more complex case, this can be three levels, with intermediate quality factors used, for example, if a different quality factor is optimal for transmitting data compared to receiving data. For example, different data rates can be used for transmission and reception. If a faster data rate is used for reception, then reception will require a higher bandwidth and therefore a lower quality factor. All other factors being equal, a coil with a relatively high quality factor will output a higher field strength for the same input power than a coil with a relatively low quality factor. This will make wireless charging more efficient. A coil with a relatively high quality factor corresponds to a lower resistance in the coil circuit, which will result in less heat being generated than a low quality factor coil for the same input power. This has benefits for heat generation and heat distribution within the receiving device.

[0027] Another reason to provide multiple different quality factors is to provide robustness to the communication link when the user is close to a metallic environment. For example, if the user is sitting in a car or sitting on a metallic chair, then if the system is operating at a high quality factor, the presence of metal may detune the system, causing one or both of power transfer and communication to fail. However, a system with a lower quality factor will waste more power, which is generally undesirable and may not be acceptable for devices that require relatively low power consumption. To alleviate this problem, the system can be configured to adaptively change the quality factor to adapt to the external environment while maintaining reasonable battery life.

[0028] The receiving device may include a coil circuit including a primary coil and a damping resistor, the damping resistor being switched in series with the primary coil to reduce the quality factor of the primary coil. The coil circuit may include one or more other damping resistors, different damping resistors or combinations of these damping resistors are used to control the amount of reduction in the quality factor.

[0029] Preferably, the IUD comprises a single axis antenna, wherein the receiving means comprises a Helmholtz coil, wherein the Helmholtz coil is arranged to communicate with the single axis antenna in order to wirelessly charge the IUD and receive the sensor data.

[0030] The single axis antenna may be configured to operate at a frequency of the order of 100 kHz, preferably in the range of 119 kHz to 140 kHz, preferably in the range of 130 kHz to 140 kHz, preferably in the range of 139.6 kHz.

[0031] The IUD may include one or more of a temperature sensor, a pH sensor, and a dissolved oxygen sensor. These sensors may be miniature electrochemical sensors integrated into the IUD, particularly suitable for human fertility analysis applications. Other biophysical parameter sensors may also be used, for example conductivity or pressure sensors may be provided. In some cases, multiple sensors of the same type (e.g. temperature sensors) may be provided at different locations on the IUD, for example in the form of a sensor array. This enables separate measurements to be taken in different areas within the uterus. For example, a first temperature sensor may be provided at one end of the IUD (close to the cervix), while a second temperature sensor may be provided at the other end of the IUD (deeper into the uterus). In this way, a temperature distribution or gradient may be inferred.

[0032] The IUD may include a body and one or more arms extending laterally from the body to secure the sensor in the uterus. This should increase the likelihood that the device will remain in place during the desired implantation period. The IUD may include a pair of arms located at or near one end of the body and generally extending away from each other. It has been found that these structures provide stable positioning of the IUD in the uterus.

[0033] The receiving device may be a wearable receiving device.

[0034] By making the receiving device wearable, it can be kept in relatively close proximity to the IUD for long periods of time, making regular monitoring easier.

[0035] The receiving device can be arranged in the clothing. The clothing can effectively ensure that the receiving device is kept near the user and in a substantially fixed position for a long time.

[0036] The garment can be a pair of underpants, for example, worn near the uterus, or a belt tied around the waist of the user. Alternatively, the wearable receiving device can be a sanitary napkin. Thus, the system causes negligible disruption to the user's daily life. The garment is also located relatively close to the IUD.

[0037] The receiving device may be a mat or blanket. Such a device may allow for long-term monitoring and / or charging, for example, while the user is lying down or sleeping.

[0038] The wearable receiving device may include a transmitter for wirelessly transmitting the received sensor data to an external device. The external device may be a portable electronic device (such as a mobile phone, tablet or dedicated phone) or a computer. The external device may be a remote server, or a database for building a sensor database.

[0039] The IUD may have an antenna disposed inside the IUD.

[0040] The IUD may have a contraceptive copper portion disposed on the outside of the IUD.

[0041] The contraceptive copper portion may be spatially separated from the antenna so that the contraceptive copper portion does not interfere with the operation of the antenna.

[0042] BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which like parts have corresponding reference numerals, and in which:

[0044] Figure 1 Schematically shows an intrauterine contraceptive system according to an embodiment of the present invention;

[0045] Figure 2 Schematically illustrates an intrauterine contraceptive device according to an embodiment;

[0046] Figure 3 schematically illustrates an intrauterine device according to another embodiment;

[0047] Figure 4A schematically illustrates a front view of a wearable garment according to an embodiment;

[0048] Figure 4B Schematically shows the Figure 4A A rear view of a wearable garment of an embodiment of the present invention;

[0049] Figure 5 Schematically shows the basis in use Figure 4A A wearable garment of an embodiment of the present invention;

[0050] Figure 6 schematically illustrates inductive coupling between a sensor device and a receiving device;

[0051] Figure 7 is a schematic block diagram of an implantable sensor device; and

[0052] Figure 8 is a more detailed schematic block diagram of an implantable sensor device.

[0053] Detailed Description

[0054] See also Figure 1 , shows a three-module structure multi-parameter in vivo sensing platform for intrauterine environment monitoring. The platform includes a smart intrauterine device sensor 1 (whose shape and size are suitable for implantation in the human uterus), an external receiver 2 and monitoring software installed on suitable data processing hardware (such as a computer 3a or a portable electronic device 3b).

[0055] Although in Figure 1 In the example shown, the receiving device 2 is a wearable receiving device 2 set in clothing, but the receiving device 2 can take any suitable form. The receiving device 2 can be a pad (e.g., Figure 1a as shown) or thick layers (e.g. Figure 1b as shown), or any other suitable device allowing long-term communication between the intrauterine device sensor 1 and the receiving device 2.

[0056] The smart IUD sensor 1 is a fully implantable (within the uterus 5 of the human female body 6) sensor device that contains multiple embedded biosensors (for measuring hormones, proteins, ions, glucose, lactate, temperature, dissolved oxygen concentration (DOC), and pH). These parameters can be monitored over a period of time to be used as a diagnostic tool. For example, oxygen depletion (as determined by dissolved oxygen concentration) may indicate endometrial cancer. Since these cancers are not usually associated with pain, they can be detected at an earlier stage. Similarly, excess estradiol may indicate endometritis.

[0057] The smart intrauterine device sensor 1 is used as a contraceptive device. The sensor 1 achieves this through chemical disruption, physical disruption, or a combined disruption mechanism. For chemical disruption, the sensor 1 releases hormones into the uterus to disrupt the intrauterine environment. In one example, the hormone is progesterone. It acts as a contraceptive in two ways to prevent pregnancy: First, excess progesterone in the uterus causes the cervical mucus to thicken, effectively preventing sperm from reaching the egg. Second, progesterone prevents the egg from being released from the ovary. In another example, the chemical may be non-hormonal, such as copper. In this example, copper acts as a contraceptive by thickening the cervical mucus, preventing sperm from reaching the egg. Second, copper prevents the fertilized egg from implanting in the endometrium.

[0058] For chemical disruption, the sensor 1 can have a membrane coating that releases progesterone, or copper wire can be wrapped around the body of the sensor 1 .

[0059] For physical disruption, the shape of the sensor 1 is suitable for being placed in the uterus and contacting at least a portion of the endometrium in the uterus. This enables the sensor 1 to disrupt the growth of the endometrium, thereby affecting the success rate of implantation of the fertilized egg to prevent pregnancy. Since the uterus is generally pear-shaped, the sensor 1 can be of any suitable shape and size. For example, the shape of the sensor 1 can be T-shaped, snake-shaped, oval-shaped. Advantageously, the shape of the sensor 1 enables the sensor 1 to be anchored in the uterus.

[0060] As previously mentioned, the sensor 1 can act as a contraceptive device using chemical and physical destruction means.

[0061] The smart IUD sensor 1 is capable of wirelessly receiving power from and wirelessly transmitting data to a wearable receiver 2, which is located outside the user's body and worn by the user. As a result, the smart IUD sensor 1 does not require batteries and cables, and is comparable in size to a standard IUD used for contraception. This is important because for uterine implantation, the device must meet strict size restrictions. Some battery-based sensors have been found to be too large to be used in the uterus. In addition, battery-based designs are often limited by the physical size of the battery and the short life before the battery is exhausted and can no longer operate. In addition, there are potential risks from the battery's toxic substances.

[0062] The receiver 2 serves as a medium between the IUD sensor device 1 and an external data processing device running suitable software (therefore operating as a data analyzer). Specifically, the receiver 2 delivers energy to the sensor device and collects real-time information. The antenna 4 of the receiver 2 can be embedded in clothing and connected to the receiver 2. The software module is developed to upload the in vivo data simultaneously to a smart terminal or PC server for later data processing and analysis. The software module consists of a set of monitoring software running on a PC or smart terminal (which is designed as a user-friendly interface for data processing and system configuration). The positioning of the smart IUD sensor 1 in the uterus is as follows Figure 1 In this example, the smart IUD sensor 1 has a generally elongated structure and is positioned generally upright (vertically) within the uterus, such that when the user is standing, the longitudinal axis of the smart IUD sensor 1 is generally vertical, however it will be understood that the vertical orientation may be achieved by other shapes (e.g., an ellipse).

[0063] In this three-module structure system, the effectiveness of wireless energy transmission and data communication between the smart intrauterine device sensor 1 and the receiver 2 directly affects the usability of the intended system. The optimized design can not only bring better performance, smaller size, lower power consumption and lower cost, but also improve the end-user experience and clinical practice.

[0064] See also Figure 2 , the figure shows an example structure of the smart intrauterine device sensor 1. Figure 2 In (a), it can be seen that the upper part of the T-shaped smart intrauterine contraceptive device sensor includes an intermediate connector 20, a first arm 21 and a second arm 22 with a connector 23. Figure 2 In (b), it is explained that the intermediate connector 20 is made of a different material having a different hardness from the joint of the first arm 21 and the second arm 22. Specifically, the body and the connector 23 use a relatively hard material, while the joint on the first arm 21 and the second arm 22 uses a relatively soft material. Figure 2 (c) shows how the first and second arms 21, 22 are bent together to assist insertion / removal during delivery to the uterus and removal. Once inserted, the first and second arms 21, 22 help to maintain the position of the smart intrauterine device sensor 1 in the uterus. Although two arms are used in this embodiment, it should be understood that in other embodiments, a single arm can be used, or more than two arms can be used, or other shapes of smart intrauterine device sensors 1 can be used.

[0065] exist Figure 2 In (d), it can be seen that the main circuit board 24 is connected to the intermediate connector 20, and the antenna 25 is fixed to the second arm 22 by the connector 23. The main circuit board 24 carries sensors and circuits, which will be described in detail below. In this arrangement, one of the arms both helps to maintain the smart IUD sensor 1 in place within the uterus, and also serves as an antenna for communicating with the receiver 2 (and receiving power from the receiver 2). The antenna 25 is generally horizontal within the uterus, which makes it particularly suitable for use with a receiver having an antenna embedded in a top. In alternative embodiments, the antenna may not form part of the arm, but may be located elsewhere. For example, the antenna may be located in the intermediate connector portion 20 (such as Figure 2 (e)).

[0066] The antenna is wrapped around the inside of the arm 22 or the intermediate connector portion 20 of the IUD sensor 1, and the IUD sensor includes a coating or material portion 26 covering the body of the sensor 1. The coating or material portion 26 contains hormonal or non-hormonal contraceptive chemicals, such as copper or progesterone, and releases the contraceptive chemicals, such as copper ions or progesterone, over time. In this example, the antenna communicates with the receiving device 2 to provide sensor data, and the coating enables the sensor 1 to be used as a contraceptive device. As previously described, the hormonal or non-hormonal contraceptive chemicals in the coating help change the intrauterine environment to prevent pregnancy. The coating or material portion 26 can be in the form of a copper winding. The coating or material portion 26 is in contact with the physiological fluid in the uterine cavity and can provide a contraceptive function.

[0067] Placing the antenna inside the IUD is beneficial because the antenna is isolated from the physiological fluids in the uterine cavity. The physiological fluids in the uterine cavity have high conductivity and the antenna will be ineffective if the coil of the wireless antenna is not isolated.

[0068] The internal antenna may be spatially separated from the contraceptive copper 26 providing the contraceptive function, or may be completely or partially located under the coil or coating providing the contraceptive function.

[0069] Regardless of the position of the antenna relative to the IUD sensor 1, the shape and size of the IUD sensor can prevent pregnancy by physically disrupting the endometrium (ie, the endometrial layer).

[0070] See also Figure 3 , showing the simplified structure of the smart IUD sensor. Figure 3 The left side of FIG. 1 shows a cross section of the intermediate connector 32, while Figure 3 The right side of the figure shows the complete smart IUD sensor 30, including the internal connections of the intermediate connector 32. The intermediate connector 32 has two sockets, here presented as rectangular slots 38, for connecting to the main circuit board 36 (with the sensor and circuit on the board), and circular slots 39, for connecting to the tubular antenna 34. As previously mentioned, the antenna 34 can be contained within the tube 34, or contained in the arm. The smart IUD sensor 30 can also include a coating on a portion of the device. For example, the coating can extend only along the intermediate connector 32, or it can extend to the entire body of the device 30. Figure 3 The sensor device is oriented perpendicular to the uterus, making it suitable for use with a receiver having a strip antenna or an antenna embedded in a panty (or disposable sanitary napkin). It should be understood that Figure 3 The sensor device in may be equipped with one or more arms to assist in stabilizing its position within the uterus (if required), or may have any other suitable shape. Compared to other types of antennas, a tubular antenna can achieve a relatively small size and be tightly wound around a ferrite core because it does not require a coil frame. Considering the manufacturing complexity and the need for the sensor to be as small as possible, a tubular antenna with a ferrite core is considered to be a particularly suitable antenna for an implantable sensor device. Antenna 34 can be a single-axis antenna, formed as a coil antenna wound around a core so that the wire is arranged circumferentially around only one axis of the core.

[0071] Figure 4A A receiver 2 is shown in the form of a wearable garment comprising a Helmholtz coil, in this case a pair of underpants 40. A front view is shown. The underpants 40 include a first Helmholtz coil 42a located at the front of the underpants 40. The first Helmholtz coil 42a is positioned so as to generally conform to the contours of the wearer's body when worn, for example, along the groove where the user's legs join the pelvis. Figure 4BA rear view of the panty 40 is shown. The panty 40 comprises a second Helmholtz coil 42b located at the rear of the panty 40.

[0072] Each Helmholtz coil is a generally planar wound wire that is protected from moisture intrusion by a moisture-tight barrier, such as by sandwiching the wire between two moisture-tight layers. Typically, a Helmholtz coil comprises a copper track disposed on a polyimide film.

[0073] Figure 5 The user is shown wearing underwear 40. The user also implants the intrauterine device sensor 1 in the uterus, as described above. The intrauterine device sensor 1 has a single-axis antenna. As previously described, the underwear 40 includes a first and a second Helmholtz coil 42a, 42b, which are located at the front and back of the underwear 40, respectively. The positioning of the coils 42a, 42b is such that the first Helmholtz coil 42a is located on a first side of the single-axis antenna 34, and the second Helmholtz coil 42b is located on a second side of the single-axis antenna 34. Since the first Helmholtz coil 42a is located on the first side of the garment and the second Helmholtz coil 42b is located on the second side of the garment, it can be seen that when the user wears the garment, the first Helmholtz coil 42a is located on the side of the user opposite to the second Helmholtz coil 42b.

[0074] Each Helmholtz coil 42a, 42b defines a respective main axis 44a, 44b, which passes through the center of the coil and is perpendicular to the plane of the coil. It can be seen that the main axes 44a, 44b of the two Helmholtz coils 42a, 42b intersect approximately at the location of the IUD sensor 1. Therefore, when current is applied to the Helmholtz coils, a very uniform magnetic field is generated between them, in which the IUD sensor 1 is located. Therefore, the IUD sensor 1 can be wirelessly charged from this magnetic field using its single-axis antenna.

[0075] When viewed from the front of the body, the direction of current in each coil can be applied in the same direction (clockwise or counterclockwise) through the front and rear coils to produce a magnetic field that is essentially aligned with the sensor's single-axis antenna located between the body's transverse planes and close to but not aligned with the body's coronal plane. Alternatively, the direction of current in each coil can be applied in a different direction through the front coil relative to the rear coil to produce a magnetic field that is essentially aligned with the sensor's single-axis antenna, which is aligned with the body's coronal plane. A magnetic field of the appropriate direction can thereby be generated depending on the orientation of the single-axis antenna. This direction may depend on the orientation of the uterus in which the device is implanted, and it is generally not possible to change this in vivo orientation. Therefore, it is very important to be able to control the direction of the applied magnetic field in the manner described above.

[0076] refer to Figure 6, showing the arrangement of the receiver 2 and the IUD sensor 1 in a manner in which they can communicate and transmit power. In FIG4 , the power generated by the AC power source 41 is transmitted from the receiver 2 to the inductively coupled IUD sensor 1 using the energy of the alternating magnetic field generated by the receiver 2. The power transmission in FIG4 is achieved by the principle of magnetic induction, wherein the wireless power transmission of the IUD sensor 1 and the communication between the two devices are both achieved using the same near-field magnetic induction link.

[0077] The receiver 2 drives the primary coil 43 at a low frequency to generate a magnetic field (in this case, the frequency is of the order of 100 kHz). The IUD sensor 1 has a secondary coil 45 near the primary (receiver) coil 43, which is inductively coupled to the receiver coil 43 (via a magnetic field H). This results in an induced voltage on the IUD sensor coil 45, which is then converted into energy by the front end 47 to power the integrated circuit 46 of the IUD sensor 1. More specifically, the front end 47 uses the energy received at the coil 45 to charge a capacitor 48, which can then be used to power the sensor circuit 46. In order to achieve high power transmission efficiency over long distances, preferably, both the receiver 2 and the IUD sensor 1 are designed to operate their antenna circuits at the same resonant frequency.

[0078] The communication between the receiver 2 and the IUD sensor 1 is achieved using the same pair of coils 43, 45 that power the IUD sensor 1. When the receiver or IUD sensor 1 manipulates the applied voltage to change the amplitude, frequency or phase of the voltage on one side, the other side will detect a similar change through the inductive link between the two devices. The message is encoded in this change, and the speed or data rate at which the message is sent depends on the bandwidth of the inductive link. Any form of modulation (amplitude, frequency or phase) will produce sidebands in the frequency domain, and if the spectrum of the modulated signal does not fall completely or substantially within the bandwidth of the inductive link, the modulated signal is difficult or impossible to detect. In this embodiment, the message transmitted from the receiver 2 to the IUD sensor 1 through the inductive link can be a command message (for example) that triggers the IUD sensor 1 to obtain a sensor reading, while the message transmitted from the IUD sensor 1 to the receiver 2 through the inductive link can be sensor data generated by a pH sensor, a temperature sensor or a dissolved oxygen sensor (for example), or a status message indicating the current state of the IUD sensor 1 (for example, power level).

[0079] See also Figure 7, shows a block diagram of a microsystem structure suitable for an intrauterine device sensor 1. In order to achieve data capture, signal processing and wireless communication, the microsystem includes an integrated sensor or a multi-sensor array 51, an analog signal conditioning circuit 52, an analog-to-digital converter (ADC) 53 (optionally including a multiplexer (MUX), a digital signal processor 54 or a microprogrammed control unit (MCU), a wireless transmitter 55 and a power manager 56. In operation, the sensor 51 converts a physical parameter into an electrical signal. The sensor can be manufactured on a micro silicon chip based on microfabrication technology suitable for the microsystem. The conditioning circuit 52 is used to improve the quality of the analog signal from the sensor 51. Generally, a more complex circuit is required for high voltage side regulation performance. A simpler regulating circuit The circuit will result in limited performance and further data processing is required after analog-to-digital conversion. Therefore, the balance between signal conditioning performance and circuit complexity should be considered in the system implementation. A multiplexer (MUX) can be used to achieve circuit hardware sharing, which has the advantages of reducing the size of the device and reducing power consumption. The processor 54 is responsible for logic control and digital signal processing. The microprogram control unit (MCU) is a widely used component with flexible functions and good scalability. At the same time, compared with powerful processors, the MCU can reduce power consumption. The wireless transmitter 55 and the power manager 56 are used for data transmission and power control, respectively. The integration of these different units can facilitate the miniaturization of the device.

[0080] See also Figure 8 , showing the main structure of the intrauterine device sensor 1 in more detail, including sensors 61a, 61b, 61c (in this case, hormones, proteins, glucose, lactate, ions, temperature, DOC and pH), corresponding analog signal conditioning units 62a, 62b, 62c (respectively used to adjust the output of each sensor 61a, 61b, 61c), a multiplexer 63a (used to allow the sensor array to interface with the ADC), an analog to digital converter 63b and an MCU 64 and a transmitter 65. It is also possible to communicate bidirectionally with the MCU from outside the body, for example to wake it up from a power-saving sleep state. In addition, the antenna can be used for wireless power transmission through inductive coupling. The transmitter 65 here includes a passive RF control unit 65a for communicating with the MCU 64 and controlling an antenna drive circuit 65b and a charging circuit 65c. The antenna drive circuit is capable of bidirectional data communication with an external receiver (antenna, ANT) through an antenna (in this case, a loop antenna) 68, and receiving power (charging voltage, VCL) through the antenna 68. Thus, it can be understood that the system utilizes wireless power transmission through inductive coupling, using low frequency RFID signals to transmit data and receive power through the user's abdominal area. The charging circuit 65c is capable of charging the capacitor 67 and is also capable of delivering power to the control unit 65a using power received through the antenna 68 and the drive circuit 65b. All power is managed through the power management block 66. Figure 8 The flow of power around the circuit is indicated by the solid directional arrows. The flow of analog data signals is indicated by the first type of dashed directional arrows. The flow of control signals is indicated by the second type of dashed directional arrows. The flow of data is indicated by the solid arrows. It can be seen that the charging capacitor 67 delivers power to the power manager 66 (which in turn manages the power delivered to the multiplexer 63a, ADC 63b and MCU 64), as well as the signal conditioning units 62a, 62b, 62c. The capacitor 67 is preferably a ceramic capacitor. This type of capacitor is particularly suitable for the present purpose for safety reasons, for example because it does not use toxic materials and has little or no risk of leakage.

[0081] The receiving device has a primary coil for wirelessly communicating with the IUD sensor, and when the receiving device wirelessly charges the IUD sensor, the quality factor of the primary coil can be controlled to be higher than the quality factor when the receiving device receives sensor data from the IUD sensor.

[0082] Since the quality factor is controllable, the same coil can be used for both efficient power transfer (wireless charging), i.e., using the coil in a (relatively) high quality factor mode, and for reliable data communication, i.e., using the coil in a (relatively) low quality factor mode.

[0083] The quality factor can be controlled by modifying the resistance associated with the primary coil. For example, a damping resistor can be connected or disconnected in series with the primary coil.

[0084] The quality factor of the primary coil can be selected between a number of different levels. In a simple case, this can be two levels - a high level for wireless charging and a low level for receiving and / or transmitting data. In a more complex case, this can be three levels, with intermediate quality factors used, for example, where a different quality factor is optimal for transmitting data compared to receiving data. For example, different data rates can be used for transmission and reception. If a faster data rate is used for reception, then the reception will require a higher bandwidth and therefore a lower quality factor. Another reason for providing multiple different quality factors is to provide robustness for the communication link when the user is close to a metallic environment. For example, if the user is sitting in a car or sitting on a metallic chair, then if the system is running at a high quality factor, the presence of metal may detune the system, causing one or both of power transmission and communication to fail. However, a system with a lower quality factor will waste more power, which is generally undesirable and may be unacceptable for a receiving device that requires relatively low power consumption. To alleviate this problem, the system can be configured to adaptively change the quality factor to adapt to the external environment while maintaining a reasonable battery life.

[0085] The receiving device 2 may include a user interface including an LCD display and a keyboard capable of displaying received sensor data and system information provided by the microcontroller, and providing the user with the convenience of operating the device through the microcontroller. The Bluetooth module may provide advanced communication with a server or smart terminal, on which data analysis may be performed.

[0086] The IUD sensor may be operable for single sampling or continuous sampling. For each sampling event, the IUD may be wirelessly charged from the receiving device in multiple steps, or the IUD sensor may be charged on demand so that whenever the stored charge in the IUD falls below a threshold, the IUD may be wirelessly charged from the receiving device.

[0087] A low power state may be a "sleep" state in which the device is essentially powered off to conserve power, but can be awakened to operate. In contrast, an idle state may be an operational state in which the device is merely waiting for instructions. The device may react faster in an idle state than in a low power (sleep) state.

[0088] As described above, electromagnetic induction wireless transmission technology performs near-field energy transmission by using two coupled coils (primary coil and secondary coil) respectively arranged at the receiving device and the implantable intrauterine contraceptive device sensor. The current flowing through the primary coil generates a magnetic field, which acts on the secondary coil, thereby generating an induced current in the secondary coil. Tight coupling is necessary to achieve high energy collection efficiency and long working distance. Increasing the distance between the coils causes the magnetic field to extend beyond the secondary coil receiving area and causes the loss of transmitted energy. In the intended application, the implantable intrauterine contraceptive device sensor requires a small size, low power consumption and a relatively short working distance of about 10 cm. This can monitor intrauterine parameters for a long time. When the intrauterine contraceptive device sensor 1 uses a hormone coating, ideally, the sensor is replaced after the hormone coating is exhausted. Typically, this can be done between 3-7 years after implantation.

[0089] Energy loss due to tissue absorption of wireless signals (electromagnetic energy is converted into other forms of energy by substances in the tissue medium, such as into heat) depends on the signal frequency. Lower frequency signals have better propagation characteristics, resulting in less tissue absorption. Therefore, the implantable intrauterine device sensor uses wireless energy transmission based on low-frequency electromagnetic induction. The wireless energy transmission circuit can also be used as wireless data communication for low-frequency RFID links, thereby reducing the need for additional circuits or circuit board space for data communication. In the intended application, in vivo information and system configuration do not require high data rate transmission, and LF RFID links can provide sufficient data bandwidth to meet the needs. The data communication range is usually farther than the energy transmission distance, which means that it is not a bottleneck for the effective working distance.

[0090] Monitoring changes in biophysical parameters within the uterus enables the IUD sensor 1 to be used to diagnose medical conditions.

[0091] While the various techniques and implantable IUD sensors and external receivers have been explained in the context of intrauterine monitoring, it will be appreciated that these techniques and structures may be applied to monitoring other body cavities, such as within the vagina, bladder, or digestive tract of the human or animal body.

Claims

1. An intrauterine contraceptive system, comprising: an intrauterine device that is shaped and sized to be implanted in the uterus; and External receiving device, wherein the intrauterine device is used to measure conditions within the uterus to generate sensor data and is used as a contraceptive device to prevent pregnancy, and Wherein, the receiving device is used to wirelessly receive the sensor data generated by the intrauterine contraceptive device.

2. The intrauterine contraceptive system according to claim 1, wherein: The receiving device is operable to wirelessly charge the implantable sensor device.

3. An intrauterine contraceptive system according to any one of the preceding claims, wherein The IUD is shaped to be anchored within the uterus.

4. An intrauterine contraceptive system according to any one of the preceding claims, wherein The IUD is shaped to contact at least a portion of the endometrium within the uterus.

5. The intrauterine contraceptive system according to claim 4, wherein: At least a portion of the IUD in contact with the endometrium disrupts the growth of the endometrium, thereby affecting the implantation of a fertilized egg to prevent pregnancy.

6. An intrauterine contraceptive system according to any one of the preceding claims, wherein The intrauterine contraceptive device releases chemical substances into the uterus to destroy the intrauterine environment.

7. The intrauterine contraceptive system according to claim 6, wherein: The chemical is located in a portion of the IUD or as a coating of a portion of the IUD, or is located in a portion of the IUD or as a portion of the IUD.

8. The intrauterine contraceptive system according to claim 6 or 7, wherein: The chemical substance is hormonal or non-hormonal, preferably one or more of copper, progesterone or estrogen.

9. An intrauterine contraceptive system according to any one of the preceding claims, wherein The receiving device comprises an antenna, a transceiver circuit and a power source, and the intrauterine device comprises an antenna, a charging circuit and a controller, wherein the receiving device is operable to transfer power from the antenna of the receiving device to the antenna of the intrauterine device by electromagnetic coupling, and the charging circuit uses the power to store power for operating a sensor of the intrauterine device and transmitting the sensor data to the receiving device.

10. The intrauterine contraceptive system according to claim 9, wherein: The intrauterine contraceptive device includes a capacitor or a rechargeable battery, and the charging circuit stores the electricity by charging the capacitor or the rechargeable battery.

11. An intrauterine contraceptive system according to claim 9 or claim 10, wherein: The power source is a rechargeable battery.

12. An intrauterine contraceptive system according to any one of the preceding claims, wherein The receiving device has a controller and a primary coil for wirelessly communicating with the intrauterine device, and the receiving device is operable to wirelessly charge the intrauterine device through inductive coupling between the primary coil and the secondary coil; wherein: The quality factor of the primary coil is controllable; The controller is operable to control a quality factor of the primary coil such that the quality factor of the primary coil is higher when the receiving device wirelessly charges the intrauterine device than when the receiving device receives sensor data from the intrauterine device; and The receiving device drives the primary coil to operate at a frequency of the order of 100 kHz.

13. An intrauterine contraceptive system according to any one of the preceding claims, wherein The IUD comprises a single axis antenna, and wherein the receiving means comprises a Helmholtz coil, wherein the Helmholtz coil is arranged to communicate with the single axis antenna in order to wirelessly charge the IUD and receive the sensor data.

14. The intrauterine contraceptive system according to claim 13, wherein: The single-axis antenna is configured to operate at a frequency in the range of 119 kHz to 140 kHz, preferably in the range of 130 kHz to 140 kHz, preferably at 139.6 kHz.

15. An intrauterine contraceptive system according to any one of the preceding claims, wherein The intrauterine device includes one or more of a temperature sensor, a pH sensor, and a dissolved oxygen sensor.

16. An intrauterine contraceptive system according to any one of the preceding claims, wherein The intrauterine device includes one or both of a conductivity sensor and a pressure sensor.

17. An intrauterine contraceptive system according to any one of the preceding claims, wherein The IUD includes a body and one or more arms extending laterally from the body to secure the sensor within the uterus.

18. The intrauterine contraceptive system according to claim 17, wherein: The IUD includes a pair of arms located at or near one end of the body and extending generally away from each other.

19. An intrauterine contraceptive system according to any one of the preceding claims, wherein The receiving device is a wearable receiving device.

20. An intrauterine contraceptive system according to any one of the preceding claims, wherein The receiving device is arranged in the clothing.

21. The intrauterine contraceptive system according to claim 20, wherein: The garment is a pair of underpants worn adjacent to the uterus.

22. An intrauterine contraceptive system according to any one of claims 1 to 18, wherein The receiving device is a mat or a blanket.

23. An intrauterine contraceptive system according to any one of the preceding claims, wherein The receiving device includes a transmitter for wirelessly transmitting the received sensor data to an external device.

24. The intrauterine contraceptive system according to claim 23, wherein The external device is a portable electronic device or a computer.

25. An intrauterine contraceptive system according to any one of the preceding claims, wherein The intrauterine device has an antenna, which is arranged inside the intrauterine device.

26. The intrauterine contraceptive system according to claim 25, wherein The IUD has a contraceptive copper portion disposed on the exterior of the IUD.

27. The intrauterine contraceptive system according to claim 26, wherein The contraceptive copper portion is spatially separated from the antenna so that the contraceptive copper portion does not hinder the operation of the antenna.

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