Modular wearable belt for non-invasive monitoring of uterine contractions, fetal movements, and fetal heart rate

Abstract

Abstract A wearable belt for non-invasive monitoring of uterine contractions, fetal movement, and fetal heart rate with a central processing and wireless data transmission unit is a modular medical wearable belt designed for non-invasive monitoring of pregnancy status. The main problem in prior systems was their restriction to monitoring one or two physiological indicators and an integrated structure that made replacement or upgrade of components difficult. The solution presented in this invention is a flexible belt with a central processing and power-supply unit and independent sensor cartridges. The sensors employed include uterine-contraction, fetal-movement, and fetal-heart-rate sensors that collect data simultaneously and, after synchronization and processing, are transmitted via a wireless communication module to a receiving device. This design enables accurate and continuous monitoring of pregnancy status without the need for complex hospital equipment, and, due to its modular structure, installation, removal, and serviceability of components can be performed easily.

Description

DescriptionTitle of Invention : Modular Wearable Belt for Non-lnvasive Monitoring of Uterine Contractions, Fetal Movements, and Fetal Heart RateTechnical Field

[0001] This idea relates to wearable equipment for non-invasive monitoring of physiological indices associated with pregnancy, including uterine contractions, fetal movements, and fetal heart rate.Background Art

[0002] In patent number US11896384B2 in 2024, entitled “Wearable maternity sensor device,” a wearable device was introduced that, using a dry electrode and a pressure sensor on the mother’s abdomen, measures intra-abdominal pressure and records the number of fetal physiological activities (such as movements). The focus of this technology was on transmitting data to a cloud server to generate a fetal health report, whereas the present idea, in addition to simultaneous monitoring of multiple indices (uterine contractions, movements, and fetal heart rate), has a modular structure and performs data processing locally.

[0003] In patent number US11207002B2 in 2021 , entitled “Fetal health monitor,” a wearable flexible sensor was disclosed that detects fetal movements using a stretch sensor on a flexible substrate. The focus of this technology was on continuous monitoring of fetal movements and analysis of movement patterns, whereas the present idea, in addition to movements, also covers uterine contractions and fetal heart rate, and its modular structure enables separation and serviceability of components.

[0004] In patent number US10595792B2 in 2020, entitled “Tocodynamometer GPS alert system,” a wearable device was presented that monitors uterine contractions with a pressure sensor and, upon detecting a labor-onset pattern, transmits a wireless alert together with the patient’s location. The focus of this technology was on alerting the first stage of labor, whereas the present ideaenables simultaneous monitoring of multiple indices and does not require sending data solely to outside centers.

[0005] In patent number US10278581 B2 in 2019, entitled “Wireless pregnancy monitor,” a wireless system was introduced that, using a patch on the mother’s abdomen, monitors uterine contractions (EMG), fetal movements, and fetal heart rate. The focus of this technology was on integrating sensors in the form of an adhesive patch, whereas the present idea, in addition to avoiding adhesive patches, offers a modular design with independent cartridges for the sensors.Technical Problem

[0006] During pregnancy, continuous monitoring of the condition of the mother and fetus is of vital importance; however, many existing equipment are usable only in hospital environments and, due to an integrated structure, do not allow separation and serviceability of components. This issue leads to increased costs and limitations of use in home environments. In addition, a portion of pregnancies are accompanied by complications such as preterm labor or abnormal changes in fetal heart rate, which require precise and long-term monitoring. Scientific reports have also shown that the use of non-invasive and remote monitoring methods can help reduce risks associated with fetal and maternal complications.

[0007] The objective of this idea is to design a non-invasive wearable belt with a modular structure that, by using independent cartridges for the sensors and a central unit for processing and wireless data transmission, enables simultaneous monitoring of uterine contractions, fetal movements, and fetal heart rate. This technical solution, in addition to resolving the limitations of existing equipment, also provides ease of use in home environments and healthcare facilities.Solution to Problem

[0008] The present idea, aiming to address existing technical problems in non- invasive pregnancy monitoring, is a modular wearable belt designed to enable simultaneous monitoring of uterine contractions, fetal movements, and fetal heart rate. The main body of the belt is made of medical elastic fabric or hypoallergenic polymer and is easily conformable to different maternal abdominal sizes. To secure the belt firmly on the body, two lateral straps (one upper and the otherlower) are provided, which are precisely adjustable using a mechanical buckle or hook-and-loop tape.

[0009] In the central section of the belt, a compartment is provided for the device’s main control unit. This unit includes a processing board that is responsible for receiving, cleaning, and synchronizing data from the sensors and preparing the results for transmission. The energy required for device operation is supplied by a rechargeable lithium-polymer battery whose capacity is designed for at least eight hours of continuous use. For safe charging, a standard charging port (such as Type-C), together with an on-board power management system, is provided on the board to control charge and discharge current and to protect the device against events such as short circuit or overcharge. For transferring the monitored information, a low-power wireless communication module (such as Bluetooth) is embedded in the circuit, which wirelessly transmits the processed data to a mobile application or an external display.

[0010] The smart belt is equipped with three separate sensors, each placed in a dedicated housing around the belt. The uterine contraction sensor is secured in an appropriate position on the mother’s abdomen using a pressure sensor to record mechanical changes resulting from uterine contractions. The motion (fetal) sensor, in addition to detecting fetal movements, sends the data required for the removal of errors (motion artifacts) from other received signals to the processing unit. Finally, the fetal heart rate sensor, which is a non-invasive sensor (such as Doppler or phonocardiography), receives the fetal cardiac signal. The raw signals received from all three sensors are transmitted to the central board via medical shielded and isolated cables that are embedded along internal pathways of the belt body.

[0011] After receiving the raw data from the sensors, the central board performs cleaning operations. These operations include signal amplification, noise filtering, and then removal of motion artifacts (with the aid of the motion sensor data) from the heart rate and contraction signals. Ultimately, all data are prepared synchronously for transmission. The prepared data are sent via the wireless module to the mobile application or the display. In the software, the monitored information is displayed as real-time charts including contractions, movements,and fetal heart rate rhythm, and the user also has the capability to store these records.

[0012] The main feature of this design is the modular architecture and the use of independent cartridges. In the event of failure or the need to upgrade any sensor, only that part is replaced and there is no need to open the entire device. This architecture, in addition to ease of repair and serviceability, increases the service life of the device and reduces maintenance cost. Moreover, the angular placement of the sensors on the belt body is implemented in such a way that signal interference is reduced and monitoring accuracy is improved.Advantageous Effects of Invention

[0013] The present invention has a set of advantages and technical superiorities compared with existing examples. First, it is wearable and completely non invasive and can be used without the need for fixed hospital equipment or clinical interventions. Second, it has a modular design based on independent cartridges; therefore, each sensor or module, in case of failure or the need for an upgrade, is replaced independently, whereas in most prior examples repair or replacement of the entire device is required.

[0014] Third, it enables simultaneous monitoring of three key pregnancy indices — uterine contractions, fetal movement, and fetal heart rate — whereas many prior systems cover only one or two indices. In this device, the central processing and power supply unit integrates all signals and transmits the data wirelessly without dependence on complex peripheral equipment or external servers.Brief Description of Drawings

[0015] Fig. 1 : General view of the device.

[0016] Fig. 2: Various views of the device from different angles.Description of Embodiments

[0017] The main body of the belt (1 ) is made of medical grade elastic textile or hypoallergenic polymer and is capable of adapting to different abdominal sizes of the mother. For better fixation of the device on the body, two lateral straps, including the upper strap (2) and the lower strap (3), are provided and are precisely adjusted by a mechanical buckle or a hook and loop fastener.

[0018] In the central portion of the body, a dedicated cartridge (4) is provided for the control unit, which includes a processing board (5) with a microcontroller architecture (such as an ESP32 or an equivalent). This board is responsible for receiving, pre processing, and synchronizing the data, and for preparing the results for transmission. Power is supplied by a rechargeable lithium polymer battery (6) whose capacity is sized for continuous use for at least an eight hour interval.

[0019] For safe charging, a USB Type C module (7) together with an on board power management system is provided so that charge and discharge current are controlled and protection against short circuit and overcharge is ensured. For data transmission, a wireless communication module (8) of the Bluetooth Low Energy (BLE) type is implemented, which transfers the processed data to a mobile application or an external display.

[0020] Around the belt, three separate cartridges are designed for the sensors. The first cartridge (9) relates to the uterine contractions sensor and fixes the FSR pressure sensor (10) in an appropriate position on the mother’s abdomen so that mechanical changes resulting from uterine contractions are recorded. The second cartridge (11 ) is the installation location for the movement sensor (12), which is of the accelerometer or IMU (inertial measurement unit) type, and in addition to detecting fetal movements, its data are used to remove motion artifacts from the other signals.

[0021] The third cartridge (13) relates to the fetal heart rate sensor, wherein a non invasive sensor (14) such as Doppler or phonocardiographic is positioned to receive the fetal cardiac signal. Each cartridge has a cable outlet path or a flexible connector that routes the signals to the central board (5). These cables are embedded in internal pathways of the belt body and are protected with medical insulation so that user safety is maintained and data transmission is performed without noise.

[0022] After receiving raw data from the three sensors, the central board performs pre processing operations including signal amplification, noise filtering, and data synchronization based on a common reference clock, and, using the movement sensor data (12), motion artifacts are removed from the signals related to fetalheart rate and uterine contractions. The prepared data are then transmitted through the Bluetooth module (8) to the application or the display, and in the software they are presented as real time plots including contractions, movements, and the fetal heart rate rhythm, with the possibility of storage.Examples

[0023] To use the device, the wearable belt is fastened on the mother’s abdominal area, and its lateral straps are adjusted so that the device is fixed in the correct position without creating excessive pressure. After installation, the control unit is turned on and the system indicates the active status of the device through a light indicator. Wireless communication between the device and the mobile application or the external display is established via the Bluetooth module, and the user can complete the connection process by running the dedicated application. At the beginning of monitoring, the user’s initial information, including general data and gestational age, is recorded in the application.

[0024] After the start of operation, the sensors installed on the belt simultaneously record the signals related to uterine contractions, fetal movements, and fetal heart rate, and the data are transferred to the central unit. The processing unit performs pre-processing including amplification, filtering, and synchronization of the data, and then the results are transmitted wirelessly to the application. The data are displayed in the application as real-time plots, and storage is possible for subsequent examinations. In addition, the user can send the recorded results to the attending physician.

[0025] After completion of monitoring, the device is turned off, and if needed the internal battery is charged through the USB Type C port. The system is designed to provide the energy required for several hours of continuous monitoring, and after a full charge it will again be ready for use. In this way, the user is able, without the need for fixed hospital equipment, to monitor the pregnancy status in the home or clinical environment and to provide accurate and reliable information to the physician.Industrial Applicability

[0026] Given the modular design, the use of commercial off the shelf components, and the capability to conform to medical equipment safety and performance standards such as IEC 60601 1 , IEC 60601 1 2, and IEC 62304, this idea is fully industrially exploitable and can be used in the manufacture of wearable medical equipment for home and clinical use.

Claims

Claims

1. A modular wearable belt for non-invasive monitoring of pregnancy, comprising: a. at least three embedded slots for installing sensor cartridges; b. independently installable and removable modular cartridges for accommodating sensors; c. heart rate sensor; d. motion sensor of accelerometer type; e. uterine contraction sensor; f. central processing unit comprising a printed circuit board to receive, amplify, filter, synchronize, and process sensor data; wherein the recorded data from the three sensors, after synchronization and motion artifact removal in the processing unit, are transmitted via a wireless communication module to a receiver device.

2. The modular wearable belt of claim 1 , wherein the sensors and the central unit are positioned in independent modular cartridges such that installation, removal, or replacement of each part is performed independently and without the need to open the entire device.

3. The modular wearable belt of claim 1 , wherein the fetal heart rate sensor includes a band-pass filter circuit to remove noise outside the cardiac signal bandwidth.

4. The modular wearable belt of claim 1 , wherein the motion sensor is a three-axis accelerometer or a multi-axis IMU, and its data are used in the processing algorithm to remove motion artifacts from fetal heart rate and uterine contraction signals.

5. The modular wearable belt of claim 1 , wherein the uterine contraction sensor is a surface pressure sensor that records pressure changes caused by abdominal contractions.

6. The modular wearable belt of claim 1 , wherein the central processing algorithm comprises: a. synchronizing the sensor data based on a common reference clock, b. removing noise and amplifying signal amplitude, c. removing motion artifacts from fetal heart rate and uterine contraction signals using the motion sensor data, d. calculating the Normalized Signal Deviation index to analyze signal quality and stability.

7. A method for non-invasive monitoring of pregnancy, comprising: a. concurrent acquisition of physiological signals from the uterine contraction sensor, the fetal motion sensor, and the fetal heart rate sensor; b. performing pre-processing on the signals including noise filtering and amplitude amplification; c. synchronizing the data using a common reference clock in the central processing unit; d. extracting motion data from the motion sensor and using it to remove motion artifacts from the uterine contraction and fetal heart rate signals; e. calculating the Normalized Signal Deviation index to analyze the quality and stability of the recorded signals; wherein the processed data are packetized and transmitted via the wireless communication module to a receiver device or display software.

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