Avoiding ‘finger cramp’ when measuring blood oxygen

Steller Startups: The uniqueness of the Oxitone Wearable Pulse Oximeter is "its ability to measure pulse rate and oxygen saturation without hindering wires and painful clips."

You know about wristwatches that can measure your pulse, but how about one that can measure your blood oxygen? There haven’t been any, until now. But thanks to Dr. Leon Eisen of Oxi- Tone Medical in Ashkelon, there is one now, and as a result, there will be far fewer cases of finger pain among patients who need to have their blood oxygen measured and monitored.
The OxiTone Wearable Pulse Oximeter actually seems like one of those ideas that you would think somebody would have come up with a long time ago. Oximeters are devices that patients with forms of COPD (chronic obstructive pulmonary disease) need to ensure that enough air is getting into the lungs.
COPD usually accompanies diseases such as chronic bronchitis and emphysema, causing the air passages to the lungs to become narrower and limiting the availability of oxygen. Patients feel short of breath, are limited in their ability to do physical activity and are at risk if they “overdo it.”
COPD is actually the thirdleading cause of death in the United States; in 2007, it cost the American economy $42.6 billion in health-care costs and lost productivity.
An oximeter (also called a saturometer) is able to indirectly monitor the oxygen saturation of a patient’s blood, avoiding the need to take a blood sample. Medicalcare personnel can monitor the level of oxygen in the blood and quickly inform doctors that help is needed if oxygen levels fall too far.
But there is a problem: Most oximeters generally require the patient to be hooked up to a battery of machines and monitors that analyzes the information, thereby requiring the patient to stay put, either in a hospital bed or at home, while the examination takes place. Numerous examinations are needed as well, so the patient has to be repeat the routine several times a day, making it very difficult for patients to engage in normal routine activities.
But the worst part is the finger pain. Current iterations of the oximeter feature “jaws” that must be clamped onto a fingertip or an earlobe – translucent parts of the body that allow the oximeter (which is based on photodiode technology) to check the level of oxygenated and deoxygenated hemoglobin in the system.
The oximeter uses two LEDs of differing wavelengths (red and infrared). Oxygenated hemoglobin absorbs more infrared light and allows more red light to pass through. Deoxygenated (or reduced) hemoglobin absorbs more red light and allows more infrared light to pass through.
The oximeter simply measures the amount and type of light being absorbed and uses that reading to determine whether there is a lack of oxygen in the blood. Considering that this procedure takes place several times a day for lengthy minutes, patients often complain of finger pain, Eisen says, even though the clamps are touted as being “pain free.”
Why clamp an oximeter on your finger or ear lobe when you can simply wear one on your wrist, just like a watch, pedometer or two-way radio (with apologies to Dick Tracy)? That’s exactly the point of the Oxi- Tone Wearable Pulse Oximeter, Eisen says.
“The uniqueness of our device is its ability to measure pulse rate and oxygen saturation without hindering wires and painful clips that ‘bite’ the finger,” he says.
“The device’s sensors are placed on the wrist and embedded into a convenient and familiar wristwatchlike enclosure. It’s much more comfortable and convenient.”
Part of that convenience is the wireless transmission of data to remote servers, without the need for wires, Eisen says.
“Tele-medicine is the next big thing,” he says, “and our device is entering the market just as there is a new demand for methods to remotely transmit data, saving time and money for both physicians and patients.”
“Because the device is wearable and communicates remotely, patients can wear it at home, when doing leisure activities, or even when they sleep,” he adds.
“Our device will provide reliable continuous monitoring and a realtime record of a patient’s state of health, through days and nights of changing activity.”
The reason Eisen is able to dispense with the finger-clamp oximeter method is because of the new measurement technology he developed.
“Our technology exploits coherent- light-speckle technology that produces a signal derived from the pulsatile blood flow” he says.
“We were able to develop a fundamentally distinct method of optical signals acquisition and processing that is resistant to the effects of movement, giving us a method to a c c u r a t e l y measure oxygen levels no matter what activity the wearer is engaged in.”
Eisen is very optimistic about the prospects for his invention, for which he has a prototype, ready for manufacture; the Wearable Pulse Oximeter is a classified consumer device, not a medical device, so he does not need to wait for FDA approval before moving forward with it.
“We believe that our device will generate a paradigm shift in continuous and prolonged health monitoring by providing a new dimension for high-quality health care,” Eisen says. “There is a great demand for a wearable and easy-to-use pulse oximeter that meets growing consumers’ demands for continuous health monitoring without compromising patients’ daily activity and sleep, and we are ready to fill that demand.”