Figure 1. This project was initiated as a response to the DoD solicitation to develop a technology for measuring hydration status, particularly in dry and hot desert conditions.
Army photograph by Spec. Eric Guzman
Armen Sarvazyan – armen@artannlabs.com
Artann Laboratories
1753 Linvale-Harbourton Rd
Lambertville, NJ 08530
Popular version of paper 4pBA6
Presented Thursday Afternoon, November 3, 2011
162nd ASA Meeting, San Diego, Calif.
Shortly after deployment in Iraq, the Department of Defense (DoD) announced a funding opportunity to help develop a technology that could measure body hydration status, particularly in dry and hot desert conditions. Our novel acoustic technology for body dehydration assessment started in response to the Army’s research solicitation. Since then, several proof-of-principle prototypes of the acoustic Hydration Monitor were developed by Artann Laboratories and tested on tissue models and in preliminary human studies which confirmed the feasibility of this new technology. As a result, a new medical application of acoustics has emerged: assessment of body hydration status by ultrasonic measurement of muscle water content. This new technology is based on the experimental fact that ultrasound velocity through soft tissue is a linear function of water content. Skeletal muscle is the largest water compartment in the body; it comprises 40 percent of body mass and 75 percent of muscle is water. The ultrasound velocity in muscle as a function of water content has the slope of about 3 m/s per 1-percent change in water content. Ultrasound velocity in tissue is evaluated by measuring the ultrasound pulse time-of-flight and the distance between the transmitting and receiving transducers. Similar to MRI, ultrasound velocity is equally sensitive to both intracellular and extracellular water.
Figure 1. This project was initiated as a response to the DoD solicitation to develop a technology for measuring hydration status, particularly in dry and hot desert conditions.
Army photograph by Spec. Eric Guzman
The need for an easy-to-perform method for detecting water imbalance also proved to be of the utmost clinical importance in vulnerable populations as well as the military application. Body hypohydration may cause severe health and performance problems, decreasing cognitive and physical work capabilities, while excessive hydration is a common symptom of many diseases. Most vulnerable population groups are infants and elderly. The dehydration of newborns is a significant clinical problem; it is a leading cause of infant morbidity and mortality worldwide. In the United States, infant dehydration accounts for 10 percent of children hospital admissions and is a major cause of newborn readmissions after discharge. A neonate’s hydration status is a critical piece of information that guides baby’s health assessment and management.
Dehydration is a frequent cause of morbidity and mortality in the elderly. Research shows that dehydration is present in up to one quarter of older patients living in nursing homes and patients with dementia are likely to be at even higher risk. It is estimated that dehydration accounts for 10 percent of hospital admissions in those over age 65.
Other vulnerable population groups are soldiers and athletes. Improved dehydration monitoring would benefit 230,000 US troops around the world, serving in areas where dehydration is a vital concern and their safe return is a top priority. Control of body hydration status is an important performance problem in sports medicine, specifically during long-term endurance exercise in hot conditions.
To date, there is no standardized, non invasive, reproducible, rapid, technically simple and not easily confounded tool to assess the body hydration status. Our study is aiming to address this problem and Figure 2 shows the general view of the proof-of-concept acoustic hydration monitor developed by Artann Laboratories. This compact battery powered device has a LCD that shows the measured ultrasonic velocity. The application time needed to acquire velocity readings is just a few seconds.
Figure 2. General view of the proof-of-principle acoustic hydration monitor and the measurement process
The device was used in a collaborative study between Artann Laboratories and research group of Dr. Alan Utter at the Appalachian State University, Boone, North Carolina, on the athletes (wrestlers) undergoing a dehydration-rehydration protocol. This quantitative cross sectional human study was completed with 47 wrestlers who volunteered to be tested in euhydrated, dehydrated, and rehydrated conditions. The ultrasound velocity measurements have clearly demonstrated ability to detect changes in hydration status of each individual subject. Notably, among the techniques tested, the ultrasound velocity measurements seemed to provide the most immediate response to dehydration and rehydration. While other control techniques utilized in the study, such as urine and plasma osmolality response, appeared to lag the ultrasound velocity response between the dehydration and rehydration phases. This preliminary human study fully confirmed feasibility of the method.
There are numerous therapeutic and diagnostic medical applications of ultrasound but it has never been used for monitoring body water content. To the best of our knowledge, Artann Laboratories is the only group in the world working on this method. Our goal is develop a versatile acoustic technology for a wide range of applications on body water balance assessment for infants, elderly, soldiers, and athletes.
Figure 1. This project was initiated as a response to the DoD solicitation to develop a technology for measuring hydration status, particularly in dry and hot desert conditions.
Army photograph by Spec. Eric Guzman