Technology


The SweetSense and SweetData technologies are commerialized through the Portland State SweetLab spin-out, SweetSense Inc. Please visit SweetSense Inc. here.

Nearly a billion people in the world lack access to safe drinking water, two billion have inadequate sanitation facilities, three billion use biomass for their daily energy needs and nearly half the world’s population live in rural isolation, lacking access to the most basic human services. Combined, these limitations are a leading cause of the perpetuating cycle of poverty and political insecurity. Meanwhile, the majority of international development agencies are responsible for self-reporting project outcomes. At best, expert spot-checks are conducted in the field occasionally. These results tend to show individual project success, while meta-surveys indicate on-going challenges in the sector.

This disconnect may be addressed through independent data monitoring technologies that provide objective data on system performance and use and can be used to demonstrate success and identify project weaknesses.

The Sustainable Water, Energy and Environmental Technologies Laboratory, the SWEETLab™, at Portland State University is working with partners to demonstrate this concept across several applications and countries. The SWEETSense™ technology can provide objective, quantitative and continuous operational data on the usage and performance of programs across a range of sectors and communities. The data is then directly integrated into SWEETData™, an internet database presenting summary statistics on performance and usage of the monitored technologies to front-end users.

The SWEETLab™ has demonstrated this technology in water, sanitation, household energy and rural infrastructure programs with diverse partners including USAID, DFID, Mercy Corps, the Lemelson Foundation, Gates Foundation partners, and DelAgua Health, in 15 countries including India, Nepal, Indonesia, Kenya, Rwanda and Haiti.

Remote monitoring systems are an innovative method to ensure the success of appropriate technology projects. Rather than infrequent engagement, remote monitoring systems ensure that community partnerships are maintained through continuous monitoring. This approach seeks to raise the quality and accountability of these projects internationally.

 Our smart-sensor technology is designed to have a low power profile, while maintaining high resolution data logging capabilities. Currently, data loggers have a tradeoff between frequency of sampling and logging, and energy consumption. However, for these applications infrequent sampling and logging (anything less than every second), can result in missing usage events that are of interest.

The SWEETSense™ technology addresses this issue by sampling at a comparatively high rate, between several times a minute and many times a second, while only logging and relaying the data when a predetermined change in the parameter is sampled. This thereby minimizes power consumption and allows high resolution logging of usage events while running off of compact batteries for a targeted minimum of six months.

The SWEETSense™ combines commercially available front-end sensors, selected for specific applications including water treatment, cookstove, sanitation, infrastructure or other applications, with a comparator circuit board that samples these sensors at a reasonably high rate. The comparator boards monitor the sensors for trigger threshold events that start and end periodic local data logging.

The comparators sample the sensors frequently, and the output is fed into a low power microcomputer chip where the relative time that the parameter change occurs is logged. Logging continues until the parameter returns to a predetermined baseline. The stored events are coded to reduce the amount of data, and thereby the amount of energy required for transmission.

One or more times per day, the comparator board relays logged data events to the internet via Wi-Fi or GSM cellular phone technology. Data processing is enabled on an internet based software program (www.sweetdata.org), where the primary algorithms are stored. The internet based program also contains manually and automatically updated calibration files that are periodically and automatically relayed back to the local sensor boards. The innovations in this invention include the processes used to enable long duration operation with high resolution data logging while operating on simple, small batteries; the use of customized and remotely updatable threshold trigger events; and the distributed data processing load between the local sensors and the internet.