Electromagnetic Energy Harvester Targeting Wearable and Biomedical Applications.

This work presents a miniaturized electromagnetic energy harvester (EMEH) based on two coils moving in a head-to-head permanent magnet tower. The two coils are separated by a set distance so that the applied force moves the EMEH from one equilibrium position to another. In this configuration, the harvester produces energy in two different working modes: when a force is applied to the moving part or when an external random acceleration is applied to the whole system.

Design Aspects for Portable LED-Based Colorimetric Characterisation Systems Targeting Liquid Analytes.

Colorimetric characterisation systems based on LEDs and RBG sensors are straightforward to implement, are highly integrable allowing for portable measurement systems and can be constructed using widespread and affordable components. They have already proved to be a satisfactory solution in several applications related to chemical analysis. In this paper, we present an RGB sensor-based prototype for colorimetric characterisation, which can accommodate cuvettes with optical paths of 10 mm and 40 mm.

Low-Cost Optical pH Sensor with a Polyaniline (PANI)-Sensitive Layer Based on Commercial Off-the-Shelf (COTS) Components.

In this paper, we presented a novel, compact, conceptually simple, and fully functional low-cost prototype of a pH sensor with a PANI thin film as a sensing layer. The PANI deposition process is truly low-cost; it performs from the liquid phase, does not required any specialized equipment, and comprises few processing steps. The resulting PANI layer has excellent stability, resistance to solvents, and bio- and chemical compatibility.

Package Design Thermal Optimization for Metal-Oxide Gas Sensors by Finite Element Modeling and Infra-Red Imaging Characterization.

We designed a 3D geometrical model of a metal-oxide gas sensor and its custom packaging and used it in finite element modeling (FEM) analysis for obtaining temperature and heat flux distribution. The 3D computer simulation, performed with GetDP software (version 3.5.

Flexible Forearm Triboelectric Sensors for Parkinson's Disease Diagnosing and Monitoring.

Existing approaches that assess and monitor the severity of Parkinson's Disease (PD) focus on the integration of wearable devices based on inertial sensors (accelerometers, gyroscopes) and electromyographic (EMG) transducers. Nevertheless, some of these sensors are bulky and lack comfortability. This manuscript presents triboelectric nanogenerators (TENGs) as an alternative stretchable sensor solution enabling PD monitoring systems.

Analysis of the capacitance of minimally insulated parallel wires implanted in biological tissue.

State of the art bioelectronic implants are using thin cables for therapeutic electrical stimulation. If cable insulation is thin, biological tissue surrounding cables can be unintentionally stimulated. The capacitance of the cable must be much less than the stimulating electrodes to ensure stimulating currents are delivered to the electrode-tissue interface.

A Wireless Wearable Sensor Patch for the Real-Time Estimation of Continuous Beat-to-Beat Blood Pressure.

This paper proposes a wireless wearable sensor system for the continuous beat-to-beat blood pressure (BP) monitoring. The real-time BP can be estimated utilising a 2-parameter regression model based on the pulse arrival time (PAT) and heart rate (HR). The PAT is defined as the time interval between the electrocardiogram (ECG) R-peak and the corresponding maximum inclination point of photoplethysmography (PPG) signal.

An Automatic Navigation and Pressure Monitoring for Guided Insertion Procedure.

Navigation is an important feature needed for medical insertion procedures. It is required to guide the medical device in the right direction at the right time. Navigation techniques used in the Wireless Capsule Endoscopy and conventional endoscopy fields are based on image-guided systems that require a large amount of data to be transferred and processed computationally.

Blood Pressure Estimation Using On-body Continuous Wave Radar and Photoplethysmogram in Various Posture and Exercise Conditions.

The pulse arrival time (PAT), pre-ejection period (PEP) and pulse transit time (PTT) are calculated using on-body continuous wave radar (CWR), Photoplethysmogram (PPG) and Electrocardiogram (ECG) sensors for wearable continuous systolic blood pressure (SBP) measurements. The CWR and PPG sensors are placed on the sternum and left earlobe respectively. This paper presents a signal processing method based on wavelet transform and adaptive filtering to remove noise from CWR signals.

Subcutaneous Solar Energy Harvesting for Self-Powered Wireless Implantable Sensor Systems.

This paper presents the study of subcutaneous solar energy harvesting for implantable sensor systems. The characteristics of a flexible solar panel under a 3 mm thick porcine skin are measured under different ambient light conditions. The output power of the solar panel when covered by the skin varies from tens of micro Watts to a few milli Watts depending on the light source.

A Locomotion Control Platform With Dynamic Electromagnetic Field for Active Capsule Endoscopy.

Conventional radiological and endoscopic techniques utilizing long tubes were ineffective in visualizing the small bowel mucosa until the development of wireless capsule endoscopy (WCE). WCE is a revolutionary endoscopic technology that can diagnose the complete gastrointestinal tract. However, the existing capsule technologies are passive, and thus they cannot be navigated to or held in a specific location.

Flexible wearable sensor nodes with solar energy harvesting.

Wearable sensor nodes have gained a lot of attention during the past few years as they can monitor and record people's physical parameters in real time. Wearable sensor nodes can promote healthy lifestyles and prevent the occurrence of potential illness or injuries. This paper presents a flexible wearable sensor system powered by an efficient solar energy harvesting technique.

A wireless capsule endoscopy steering mechanism using magnetic field platform.

In this paper, a new steering mechanism for wireless capsule devices is presented. The proposed system consists of a platform generating a magnetic field to direct and control the motion of a capsule. The platform contains an upper and a lower set of electromagnets.

A sub 125 nW sub-threshold analog adaptive sampler in 180 nm CMOS.

We present an ultra low power analogue adaptive sampler for extraction of features from an arterial blood pressure signal, prior to ADC operation or conversion. The architecture is implemented and simulated in UMC 180 nm technology. A worst case power consumption across process variation of 124.

Comparison of the impedance cardiogram with continuous wave radar using body-contact antennas.

This paper describes a continuous wave (CW) radar system with body-contact antennas and basic signal processing. The goal is to assess the signals' reproducibility across different subjects as well as a respiration cycle. Radar signals using body-contact antennas with a carrier frequency of 868 MHz are used to acquire the cardiac activity at the sternum.

Development of a wearable plantar force measurement device for gait analysis in remote conditions.

The pressure field that exists between the foot and the supporting surface is identified as the foot plantar pressure. The information obtained from foot plantar pressure measurements has useful applications that include diagnosis of gait disturbances, optimization of footwear design, sport biomechanics and prevention of injury. Using wearable technology to measure foot plantar pressure continuously allows the collection of comprehensive real-life data sets while interfering minimally with the subject's daily activities.

Systolic Time Interval Estimation Using Continuous Wave Radar With On-Body Antennas.

Unlabelled: The estimation of systolic time intervals (STIs) is done using continuous wave (CW) radar at 2.45 GHz with an on-body antenna.

Motivation: In the state of the art, typically bioimpedance, heart sounds and/or ultrasound are used to measure STIs.

Integration of Low-Power ASIC and MEMS Sensors for Monitoring Gastrointestinal Tract Using a Wireless Capsule System.

This paper presents a wireless capsule microsystem to detect and monitor the pH, pressure, and temperature of the gastrointestinal tract in real time. This research contributes to the integration of sensors (microfabricated capacitive pH, capacitive pressure, and resistive temperature sensors), frequency modulation and pulse width modulation based interface IC circuits, microcontroller, and transceiver with meandered conformal antenna for the development of a capsule system. The challenges associated with the system miniaturization, higher sensitivity and resolution of sensors, and lower power consumption of interface circuits are addressed.

A 180 nm CMOS analog adaptive sampler for blood pressure feature extraction.

This paper presents an analogue feature detector for extraction and sampling of key-points on an arterial blood pressure signal in both humans and small mammals used as human physiological models. A CMOS integrated circuit was implemented in UMC 180nm technology, utilizing the proposed sampling method to greatly reduce the number of samples necessary for meaningful reconstruction of the low bandwidth signal. This circuit was interfaced with an external ADC to fully extract the feature points, and evaluate the system performance.

Improving resolution of robotic capsule locomotion using dynamic electromagnetic field.

This paper describes a new method to control the motion of swallowable wireless capsule endoscopy devices. A dynamic magnetic field produced by a set of external magnetic coils is used to manage the locomotion of the capsule. A permanent magnet is embedded into the capsule in order to manipulate the capsule by changing the external magnetic field strength for each specific position.

A MEMS Interface IC With Low-Power and Wide-Range Frequency-to-Voltage Converter for Biomedical Applications.

This paper presents an interface circuit for capacitive and inductive MEMS biosensors using an oscillator and a charge pump based frequency-to-voltage converter. Frequency modulation using a differential crossed coupled oscillator is adopted to sense capacitive and inductive changes. The frequency-to-voltage converter is designed with a negative feedback system and external controlling parameters to adjust the sensitivity, dynamic range, and nominal point for the measurement.

Cuffless blood pressure estimation from the carotid pulse arrival time using continuous wave radar.

Ambulatory blood pressure monitors based on pulse transit time are limited by the challenge of changing vascular tone. This study focuses on the use of the carotid artery as an alternative location for arterial pulse acquisition. We use continuous wave radio frequency (RF) radar coupled directly to the body to detect the pulse wave signal.

Wireless power transmission for biomedical implants: The role of near-zero threshold CMOS rectifiers.

Biomedical implants require an electronic power conditioning circuitry to provide a stable electrical power supply. The efficiency of wireless power transmission is strongly dependent on the power conditioning circuitry specifically the rectifier. A cross-connected CMOS bridge rectifier is implemented to demonstrate the impact of thresholds of rectifiers on wireless power transfer.

A 1.04µW wireless integrated MEMS interface in UMC 0.18µm CMOS.

This paper presents an ultra low-power integrated interface for capacitive and resistive MEMS and sensors, intended for use in biomedical applications. The interface encodes the sensed data in the time between transmitted UWB pulses: this reduces the number of transmitted bits and benefits the power consumption. The interface was designed and fabricated in the UMC 0.

Meandered conformal antenna for ISM-band ingestible capsule communication systems.

The wireless capsule has been used to measure physiological parameters in the gastrointestinal tract where communication from in-body to external receiver is necessary using a miniaturized antenna with high gain and onmidirectional radiation pattern. This paper presents a meandered conformal antenna with center frequency of 433 MHz for a wireless link between an in-body capsule system and an ex-body receiver system. The antenna is wrapped around the wireless capsule, which provides extra space for other circuits and sensors inside the capsule as well as allows it having larger dimensions compared to inner antennas.