Remo Lombardi

Data acquisition system for measurements in free moving subjects and its applications

A low-cost, portable acquisition system for monitoring and processing human biomechanical parameters is presented. It is equipped with 16 input channels, each one linked to an external transducer by a suitable connector. Input signals from sensors are converted into a digital form by a 12-bit analog-to-digital converter and stored in a removable memory (memory card) respecting the PCMCIA standard interface, allowing the download of acquired data toward the host computer. The acquisition operating mode is programmable by a host PC, writing proper values into the memory card; then, the instrument acquires the defined number of channels at the selected sampling rate. The instrument is battery powered; then, it can be used in all those applications, like rehabilitation and sports medicine, where the freedom for subject movement is a constraint for the test. In fact, this instrument does not require an arranged environment for measurements, and it is not connected to a PC. Three sample applications are presented in which the instrument is used to evaluate human motor capability, physical parameters in amputees, and motor performance in athletes.

Design and development of a novel capacitive sensor matrix for measuring pressure distribution

This work illustrates the design and realization of a mattress made of capacitive sensors that measures the pressure distribution and the center of pressure of a person, while driving a car for long periods of time. The scope of this device is to obtain a system able to detect important parameters without being perceived by the subject. The continuous and automatic measurement of the individuals movements contributes in the assessment of the psyco-physical condition of the driver, mainly regarding the level of discomfort, which influences the degree of fatigue and, as a consequence, the concentration of the subject.

Flow Rate Profiler: an instrument to measure blood velocity profiles.

In this paper we present Flow Rate Profiler (FRP), an instrument for measuring the blood velocity by means of ultrasound-based techniques. The velocity is directly related to the shear rate, which is in turn proportional to the shear stress, a parameter expressing the pressure exerted by the blood on the vessel walls. The knowledge of this value is important in medicine to establish the state of the vessels, directly related to vascular diseases. FRP provides a non-invasive measure of the blood velocity by exploiting the red corpuscles property of diffusing ultrasound waves: in practice blood velocity is determined by a cross-correlation technique, which analyses the time shift between correlated subsequent echo waves, instead of frequency shift characteristic of the Doppler technique. The acquired data are then processed on a personal computer by means of mathematical techniques based on the evaluation of the correlation function, giving a reconstructed velocity profile and showing a good adherence with experimental data, since the average error is nearly the 10%. The reconstructed profile is displayed to the operator, who can follow the vessel status in real time. A few comparisons between the reconstructed and the experimental profiles are also presented, together with a study on a small set of patients suffering from artery hypertension.

Self-Adaptive Prototype for Seat Adaption

Self-adaptive prototype for seat adaptation aims at enhancing the physical comfort of a driver by taking into account not only the state of the environment (state of the road, car settings), but also the driver’s emotional, cognitive and physical state. To implement this prototype we used a REFLECTive middleware, which provides a programming framework for the development of pervasive-adaptive applications. The REFLECTive middleware supports self-adaptive behavior and is generally composed of three tiers: Tangible tier contains services that read sensors data and send commands to actuators, REFLECTive tier is responsible for analyzing the data collected from sensors and for defining the actions that will be performed by actuators, Application tier facilitates high-level decision making. The seat adaptation prototype uses the information about Center of Pressure (COP) speed and number of bumps to determine the driver’s physical state, and then it combines this information with the driver’s cognitive and emotional state to figure out if the driver feels uncomfortable, and to change the state of seat cushions in an attempt to make driver feel more comfortable. The components of the seat adaptation prototype in the REFLECTive and Application tier are implemented using reaction rules.

A correlator for light scattering experiments

Light scattering is frequently used to examine the random motion of physical system particles. By evaluating the autocorrelation function of the acquired signal, structural information of macromolecular solutions can be obtained. Here we present an instrument that is able of calculating the correlation function in real time. The instrument features high-precision capabilities and a wide range of selectable delays. A digital signal processor (DSP) is charged with the calculations, whereas a PC permits the user the management of the global instrument and the visualization and the storing of the evaluated correlation.

A Multi-Purpose Wireless Sensor Network Based on Zigbee Technology

Among a wide offer of wireless technologies, ZigBee is one of the most actractive for connecting low–volume devices, such as sensors. This paper aims at presenting a project which is being carried on at Microcomputers and Biomedical Devices laboratory (Department of Computer Science, Faculty of Engineering, University of Pavia, Italy). The goal of the project is the development of a prototype of ZigBee sensors network for temperature monitoring. The idea is to evaluate the capability of ZigBee technology in order to build wireless sensors networks for environmental monitoring. The use of a single chip which integrates a microcontroller and a ZigBee transceiver gives the possibility of developing wireless devices with small dimensions, low power consumption, and a good computing capability.

A Portable System for Measuring Human Body Movement

A low cost portable acquisition system for monitoring and processing human body segment movements is presented It is equipped with 32 multiplexed input channels, each one linked to an external 2 axis MEMS accelerometer. Input signals from sensors are converted into a digital form by a 10 bit analog to digital converter and transmitted via Bluetooth technology to a remote PC. The instrument is battery powered and then it can be used in applications like ergonomics, rehabilitation and sport medicine. Labview 7.1 has been used to visualize in real time the human body segment movements

Portable acquisition system for measurements of pressures, temperatures and humidity in lower limb prosthesis

An instrument with a DSP for measurements of pressures, temperatures and humidity in lower limb prosthesis is presented. It has got sixteen analog input channels. The signals from the transducers are linked to the input channels and feed the conditioning network which is made up by amplification stages and peak detectors. Input signals are converted into a digital form by a 10 bit analog to digital converter integrated into the DSP and information are pre-processed and then stored in a removable memory with high capacity. The instalment is also equipped with an LCD display to show the progress of the interesting parameters in real time. Now we are testing the instrument at the Prosthetic Center in Vigorso di Budrio (Italy). The aim of these tests is checking the correct operation of the instrument in different working ways and bringing constructive modifications to prosthesis to better locate the sensors.

WESNEP: A Wireless Environmental Sensor Network for Permafrost Studies

The aim of this paper is to give an overview of WESNEP, an environmental wireless sensor network which is currently being developed at the University of Pavia in order to study alpine permafrost. After a brief introduction on environmental sensor networks and the definition of permafrost, the motivation of WESNEP project and the architecture of the network are described, finally the main benefits expected from the project are presented.

A Wireless Sensors System for Sport Studies

A system based on wireless sensors for biomechanical and sport applications is presented. It is currently used to study the interaction between athletes and sport surfaces, such as soccer turves and athletic tracks, with special focus on ankle vibrations. Thanks to a Bluetooth connection, the wireless sensors can communicate with a PC, where data are visualized and elaborated in real time. Thus, the subject under test can move freely, since there are no cable constraints.