NBM 200 system accurately measures hemoglobin level

Oct 11 2010

OrSense Ltd., developer of monitors for non-invasive measurements of various blood parameters, presented today at the AABB Annual Meeting & CTTXPO 2010, in Baltimore, Maryland, results showing that hemoglobin (Hb) measurements obtained by its NBM 200, a non-invasive Hb measurement system for anemia screening, showed accurate performance compared with invasive point of care (POC) devices.

“OrSense's non-invasive solution has the potential for improving anemia screening and monitoring by eliminating pain, reducing infection risk and enabling a simple and fast diagnosis.”

Hemoglobin measurements allow the detection of anemia and hemorrhage, and are widely used by hospital wards such as operating rooms, ICU, emergency and delivery rooms as well as in outpatient clinics and women's and children's health care facilities. In blood donation centers, a predonation Hb measurement of blood donors is required by most countries to protect anemic donors, and to ensure adequate Hb content of blood units. The determination of Hb levels of prospective blood donors is usually performed using capillary blood obtained by finger pricking, rendering current Hb screening methods invasive, painful, time consuming and labor intensive.

"Two billion people—over 30 percent of the world's population—are anemic, mainly due to iron deficiency. In blood banks, adequate Hb screening is thus imperative in order to ensure donor safety and blood units' quality. Anemia is even more common in hospitalized patients, and negatively affects prognosis of several medical conditions," said Dr. Paul Holland, Former President of the International Society of Blood Transfusion (ISBT). "OrSense's non-invasive solution has the potential for improving anemia screening and monitoring by eliminating pain, reducing infection risk and enabling a simple and fast diagnosis."

Results of the Hb clinical trials

The clinical trials were conducted at the VA Medical Center (Milwaukee, Wisconsin) and the hematology and blood bank department of Assaf Harofeh Medical Center (Zerifin, Israel) on 563 volunteers (303 male, 260 female) in the age range 18-68 years. Upon receipt of informed consent, the NBM sensor was placed on the subject's thumb, and non-invasive Hb measurements were recorded. Reference values were obtained from venous samples and evaluated on a Coulter LH 750 blood analyzer or Radiometer OSM3 CO-Oximeter.

Hb reference values ranged from 7 to 17.2 g/dL, with an average of 12.5 g/dL. The mean difference (bias) between the NBM readings and the reference was 0.1 g/dL, the mean absolute error was 0.75 g/dL, and the standard deviation of error (SD) was 0.92 g/dL. The NBM 200 had a false positive ratio of 6.4% and false negative ratio of 8.6%. Over 46.4% of Hb readings were under 12.5 g/dL, the exclusion border line commonly used in blood donation centers. Focusing on more significant anemic values, there were 243 (24.5%) data points that fell under 11 g/dL, and the NBM identified 96% of them as anemic. Under 10 g/dL there were 110 (11%) points, and they were all identified by the OrSense system.

Non Invasive Hemoglobin Measurement

OrSense's non-invasive Hb measurement has many advantages including the prevention of pain and potential transmission of infectious diseases, a reduced need for trained personnel, short measurement time, and the absence of bio-hazardous waste. NBM 200 offers a unique, breakthrough, non-invasive solution for accurate and quick Hb measurements. This portable device operates via a ring-shaped sensor that is fitted on the donor's finger and applies pressure, temporarily occluding local blood flow. During the occlusion, optical elements in the sensor perform a sensitive measurement of the light transmitted through the finger. This method, called Occlusion Spectroscopy, provides a quick, accurate and painless measurement of the donor's blood constituents, while greatly improving the donor's comfort, eliminating infection risk, and providing the medical staff with accurate readings and immediate results.