| US 7,463,343 B2 | ||
| Sensing systems and methods for differentiating between different cellular blood species during extracorporeal blood separation or processing | ||
| Matthew R. Muller, Lindenhurst, Ill. (US) | ||
| Assigned to Fenwal, Inc., Lake Zurich, Ill. (US) | ||
| Filed on Oct. 15, 2007, as Appl. No. 11/974,650. | ||
| Application 11/974650 is a division of application No. 11/255356, filed on Oct. 21, 2005, granted, now 7,282,154. | ||
| Application 11/255356 is a division of application No. 10/280109, filed on Oct. 24, 2002, granted, now 7,011,761. | ||
| Application 10/280109 is a continuation in part of application No. 09/931146, filed on Aug. 16, 2001, granted, now 6,537,445. | ||
| Application 09/931146 is a continuation of application No. 09/389912, filed on Sep. 03, 1999, granted, now 6,284,142. | ||
| Prior Publication US 2008/0094610 A1, Apr. 24, 2008 | ||
| Int. Cl. G01N 33/48 (2006.01) | ||
| U.S. Cl. 356—39 [356/40] | 2 Claims |
| 1. An optical sensing assembly for differentiating between the presence of platelets and red blood cells in a plasma flow
comprising
a first emitter of light at a first wavelength (λ1) having a known optical attenuation for platelets at the first wavelength (εplateletsλ1) and a known optical attenuation for hemoglobin at the first wavelength (εHbλ1),
a second emitter of light at a second wavelength (λ2) having a known optical attenuation for platelets at the second wavelength (εplateletsλ2) and a known optical attenuation for hemoglobin at the second wavelength (εHbλ2),
wherein:
λ1≠λ2;
εplateletsλ1≈εplateletsλ2
εHbλ1>εHbλ2,
a path transparent to light at the first and second wavelengths to convey the plasma flow past the first and second emitters,
a light detector to receive light emitted by the first and second emitters through the path and to generate signals proportional
to intensities of received light, and
a module coupled to the light detector to analyze the signals to derive intensities of the received light at the first and
second wavelengths and generate an output representing presence of a blood cell concentration in the plasma flow, and to compare
changes in the signals over time to derive changes in intensities of received light at the first and second wavelengths over
time and generate an output that differentiates between changes in intensity attributable to changes in platelet concentration
in the plasma flow and changes in intensity attributable to changes in red blood cell concentration in the plasma flow.
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