This device continuously checks your blood pressure.

What a Little Federal Funding Can Do

December 2007 / January 2008 By: Suzanne Finch Volume 5 Number 6

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Anyone who has ever had a routine physical exam has had his blood pressure measured with a familiar device that uses an inflatable cuff that encircles the arm. While blood pressure changes constantly (depending upon a patient's position, state of rest, motion and other factors) this device records a snapshot of the blood pressure for a single moment.

While standard arm cuff blood pressure measurement is generally fine for most patients, there is often a need to get a continuous blood pressure (beat-by-beat) reading. Beat-by-beat blood pressure readings are sometimes required for patients with low blood pressure in case of shock, vascular disease and chronic high blood pressure (hypertension).

By far, the most common technique of measuring beat-by-beat blood pressure is through the use of an arterial catheter which uses a thin, hollow tube placed into an artery of the patient (most commonly of the wrist or groin). This is often accompanied by pain, infections and (rarely) blood clots.

Empirical Technologies of Charlottesville, Va., has found a solution to these potential risks by creating the first non-invasive, comfortable beat-by-beat arterial blood pressure monitor. With funding from the Office of Naval Research, the company engineered a wrist brace-style device that, as it turned out, had many applications, both in the military and civilian life. The device was trademarked under the name CareTaker.

The device uses a very lightly pressurized cuff that goes around the index finger. The sight pressure from the cuff couples to the pulse wave as it goes through the artery in your finger. Piezoelectric technology (similar to that used in fireplace lighters and gas stoves) is used in CareTaker to record pulse measurements from the cuff. These data are sent to a nearby computer, where blood pressure information is extracted. "It also gives us a whole spectrum of information," says David Gerdt, president and co-founder of Empirical Technologies. "It tells us what is going on in the aorta because CareTaker actually tracks central blood pressure."

To test the effectiveness of the technology, Empirical needed additional funding to build prototypes. Gerdt had heard of the Office of Technology Transfer and Commercialization and applied for funding. OTTC manages the Center for Commercialization of Advanced Technology (CCAT) at California State University, San Bernardino. With programs located at San Bernadino and San Diego State University, the CCAT program is tasked by the Department of Defense to seek out promising technologies invented by small entrepreneurs, academic researchers and government labs. The CCAT staff then guides the inventors/entrepreneurs through tech transfer processes resulting in products that can be used by the military and homeland security personnel.

Empirical Technologies was awarded $75,000 in November 2005. It was this CCAT funding that allowed the company to build their first six pre-production prototypes of CareTaker. They were also awarded a market study that examined potential customers, competitors and industry trends.

The market study proved helpful. "The market study did two things: it confirmed what we already knew and it also opened up some new areas that we didn't know very much about," said Gerdt. "So it gave us a good feeling that we'd been going along in the right direction and it gave us directions where we should go and, since, have gone." These included additional uses in the military to determine the stress levels in military personnel, which is currently being undertaken by the Navy.
In 2006, Empirical was awarded another $40,000 by OTTC to build 25 additional prototypes that were later distributed to military medical research facilities. CareTaker is being evaluated at Walter Reed Army Hospital, the Army Institute of Surgery and the Naval Health Research Center

Using the same piezoelectric technology in a different way, Empirical began development of the HRWatch in 2005. As the name suggests, the HRWatch is wristwatch-style device that records a continuous measure of a patient's heart rate. It is the only device to be able to do so without the use of a chest strap or other electrodes. "This means it can be worn all night with very little thought," said Gerdt.
In 2007, Empirical was also awarded CCAT grant of $20,000 through OTTC to produce 20 pre-production prototypes of the HRWatch. These prototypes are currently being tested at the Naval Hospital Research Center in San Diego.
The company is also working with another partner to manufacture a version of the HRWatch that would be able to monitor at-risk patients for sudden cardiac arrest. "There are over 500,000 of those in the U.S. every year," said Gerdt, who pointed out that if the patient is stricken in a location with a defibrillator, such as an airport or casino, the chances of survival are over 70 percent. "If you're at home, it's about 10 percent," he said. The proposed design of the watch will send a signal to the patient's cell phone, triggering a call to a national hotline that will utilize Global System for Mobile (GSM) communications technology. The GSM then locates the position of the patient wearing the watch. The next step is to send text messages to medical personnel in the area alerting them to the location of both the patient and the nearest defibrillator—€” all in less than three minutes.
While the HRWatch and CareTaker continue to evolve, the prototypes funded by OTTC continue in their importance to determine additional product applications and features. "You can give the prototypes to doctors and physiologists and they will tell you what they don't like about them and they also tell you about the features they would like to see," said Gerdt. "So you get an idea of what they're looking for—€”in other words, you get the market explained to you by people who are going to buy the product."

Suzanne Finch is spokesperson for the CCAT program.