公开(公告)号：US4892101A

公开(公告)日：1990-01-09

申请号：US315330

申请日：1989-02-24

申请人： Peter W. Cheung ,  Karl F. Gauglitz ,  Lee R. Mason ,  Stephen J. Prosser ,  Robert E. Smith ,  Darrell O. Wagner ,  Scott W. Hunsaker

发明人： Peter W. Cheung ,  Karl F. Gauglitz ,  Lee R. Mason ,  Stephen J. Prosser ,  Robert E. Smith ,  Darrell O. Wagner ,  Scott W. Hunsaker

IPC分类号： A61B5/00

CPC分类号： A61B5/14551

摘要： A feedback control system is disclosed for use in processing signals employed in pulse transmittance oximetry. The signals are produced in response to light transmitted through, for example, a finger at two different wavelengths. Each signal includes a slowly varying baseline component representing the relatively fixed attenuation of light produced by bone, tissue, skin, and hair. The signals also include pulsatile components representing the attenuation produced by the changing blood volume and oxygen saturation within the finger. The signals are processed by the feedback control system before being converted by an analog-to-digital (A/D) converter (72) for subsequent analysis by a microcomputer (16). The feedback control system includes a controllable offset subtractor (66), a programmable gain amplifier (68), controllable drivers (44) for the light sources (40, 42), and the microcomputer (16). The microcomputer (16) receives signals from the offset subtractor (66), gain amplifier (68), drivers (44) and A/D converter (72) to produce signals that control the function of the subtractor (66) and drivers (44) in the following manner. Normally, the drivers ( 44) are maintained within a predetermined current range. In the event the microcomputer (16) senses an output from the converter (72) that is not within a predetermined range, the drive signal is adjusted to produce an acceptable signal. The magnitude of the offset removed by the subtractor (66), as controlled by the microcomputer (16), is maintained at a constant level when the converter (72) output is within a first predetermined range and is a predetermined function of the converter (72) output when that output falls within a second predetermined range.

摘要翻译： 公开了一种反馈控制系统，用于处理脉冲透射比率测定中使用的信号。 信号是响应于透过例如两个不同波长的手指的光产生的。 每个信号包括缓慢变化的基线分量，其表示由骨，组织，皮肤和头发产生的光的相对固定的衰减。 信号还包括表示由手指内的血液体积变化和氧饱和度产生的衰减的脉动成分。 这些信号由模拟数字（A / D）转换器（72）转换之前由反馈控制系统处理，用于微计算机（16）的后续分析。 反馈控制系统包括可控偏移减法器（66），可编程增益放大器（68），用于光源（40,42）的可控驱动器（44）和微计算机（16）。 微型计算机（16）从偏移减法器（66），增益放大器（68），驱动器（44）和A / D转换器（72）接收信号，以产生控制减法器（66）和驱动器（44）的功能的信号 ）。 通常，驱动器（44）保持在预定的电流范围内。 在微计算机（16）感测到转换器（72）的输出不在预定范围内的情况下，调节驱动信号以产生可接受的信号。 当转换器（72）输出在第一预定范围内并且是转换器的预定功能时，被微计算机（16）控制的减法器（66）去除的偏移量的幅度保持在恒定水平 72）当该输出处于第二预定范围内时输出。

公开(公告)号：US4819646A

公开(公告)日：1989-04-11

申请号：US897664

申请日：1986-08-18

申请人： Peter W. Cheung ,  Karl F. Gauglitz ,  Lee R. Mason ,  Stephen J. Prosser ,  Robert E. Smith ,  Darrell O. Wagner ,  Scott W. Hunsaker

发明人： Peter W. Cheung ,  Karl F. Gauglitz ,  Lee R. Mason ,  Stephen J. Prosser ,  Robert E. Smith ,  Darrell O. Wagner ,  Scott W. Hunsaker

IPC分类号： A61B5/145 ,  A61B5/00 ,  A61B5/1455 ,  A61B6/00

CPC分类号： A61B5/14551

摘要： A feedback control system is disclosed for use in processing signals employed in pulse transmittance oximetry. The signals are produced in response to light transmitted through, for example, a finger at two different wavelengths. Each signal includes a slowly varying baseline component representing the relatively fixed attenuation of light produced by bone, tissue, skin, and hair. The signals also include pulsatile components representing the attenuation produced by the changing blood volume and oxygen saturation within the finger. The signals are processed by the feedback control system before being converted by an analog-to-digital (A/D) converter (72) for subsequent analysis by a microcomputer (16). The feedback control system includes a controllable offset subtractor (66), a programmable gain amplifier (68), controllable drivers (44) for the light sources (40,42), and the microcomputer (16). The microcomputer receives signals from the offset subtractor (66), gain amplifier (68), drivers (44) and A/D converter (72) to produce signals that control the function of the subtractor (66) and drivers (44) in the following manner. Normally, the drivers (44) are maintained within a predetermined current range. In the event the microcomputer (16) senses an output from the converter (72) that is not within a predetermined range, the drive signal is adjusted to produce an acceptable signal. The magnitude of the offset removed by the subtractor (66), as controlled by the microcomputer (16), is maintained at a constant level when the converter (72) output is within a first predetermined range and is a predetermined function of the converter (72) output when that output falls within a second predetermined range.

公开(公告)号：US4869253A

公开(公告)日：1989-09-26

申请号：US897662

申请日：1986-08-18

申请人： Kenneth C. Craig, Jr. ,  Karl F. Gauglitz ,  G. Michael Losh ,  Lee R. Mason ,  Richard C. Nova ,  James W. Taylor ,  Stephen J. Prosser

发明人： Kenneth C. Craig, Jr. ,  Karl F. Gauglitz ,  G. Michael Losh ,  Lee R. Mason ,  Richard C. Nova ,  James W. Taylor ,  Stephen J. Prosser

IPC分类号： G01N21/31 ,  A61B5/00 ,  A61B5/145 ,  A61B5/1459

CPC分类号： A61B5/14551 ,  A61B5/7207

摘要： The present invention discloses a method and apparatus for indicating perfusion and oxygen saturation trends in oximetry. In transmittance and reflectance oximetry, LEDs (40, 42) are typically employed to expose tissue to light at two different wavelengths. The light transmitted through, or reflected by, the tissue is received by a detector (38) where signals proportional to the intensity of light are produced. These signals are then processed by oximeter circuitry (14, 16) to determine oxygen saturation, pulse rate, and perfusion. Displays (20) are provided including a display (132, 134) of the change in the oxygen saturation during a specified interval. This display may include first (132) and second (134) trend indication displays that indicate when the oxygen saturation has either been increasing or decreasing at a rate in excess of some predetermined level. Preferably, these displays are triangular, upwardly and downwardly directed light-emitting diodes. A digital display (138) of the change in oxygen saturation may also be provided. A second type of display included provides pulse and perfusion information, with the perfusion being displayed as a logarithmic function of the actual perfusion. This display comprises an aligned array of light-emitting diodes (136) with the number of LED's lit imaging the plethysmigraphic waveform, peak to peak scaling is employed which is indicative of signal level and perfusion.