专利快速检索-快速检索全球专利，免费商用专利数据库-IPRDB

1. 发明授权

US5020541A Apparatus for sensing lead and transthoracic impedances 失效
公开(公告)号：US5020541A
公开(公告)日：1991-06-04
申请号：US464348
申请日：1990-01-12
申请人： Arthur R. Marriott
发明人： Arthur R. Marriott
IPC分类号： A61B5/0424 , A61B5/053
CPC分类号： A61B5/0535 , A61B5/0424
摘要： A method and apparatus for use with medical electrode systems that sense the integrity of lead connections and patient transthoracic impedance is provided. In an ECG electrode application, a carrier circuit (12) produces two carrier signals (S.sub.C1 and S.sub.C2) that are out of phase with each other. The S.sub.C1 signal is applied to an RA lead through a terminating impedance (Z1). The S.sub.C2 signal is applied to LA, LL and V leads through terminating impedances (Z2, Z3, and Z4). Each of the S.sub.C1 and S.sub.C2 carrier signals comprises a lead impedance frequency component (S.sub.LI) and an impedance respiration frequency component (S.sub.IR). First stage amplifiers (A1, A2, and A3) located in an ECG preamplifier (13) amplify the difference between a lead voltage on the RA lead (V.sub.RA) and lead voltages on the LA, LL, and V leads (V.sub.LA, V.sub.LL and V.sub.V). High pass filters (F1, F2 and F3) remove patient ECG signals from the outputs of A1, A2 and A3 to produce first stage output voltages (V.sub.1, V.sub.2 and V.sub.5). The V.sub.1, V.sub.2 and V.sub.5 voltages are demodulated by a demodulator circuit (18). Lead impedance demodulators (DM1, DM2 and DM3) are clocked by a lead impedance control signal (S.sub.A) that has the same frequency as the S.sub.LI component so that the outputs of DM1, DM2 and DM3 are lead impedance-related voltages (V.sub.L1, V.sub.L2 and V.sub.L5). V.sub.2 is also demodulated by an impedance respiration demodulator (DM4). DM4 is clocked by an impedance respiration control signal (S.sub.B) that has the same frequency as the S.sub.IR component so that the output of DM4 is a transthoracic impedance-related voltage V.sub.T. V.sub.T is amplified by an operational amplifier (OA10) to produce an impedance respiration-related voltage (V.sub.R). The ECG preamplifier (13) and the demodulator circuit (18) include fast DC restoration circuits (66, 68, 70 and 71) that use switched capacitor integrators (76) to restore ECG outputs (V.sub.E1, V.sub.E2, and V.sub.E5) and the V.sub.R voltage to nominal values when a DC offset has occurred.

2. 发明授权

US4919145A Method and apparatus for sensing lead and transthoracic impedances 失效
公开(公告)号：US4919145A
公开(公告)日：1990-04-24
申请号：US219080
申请日：1988-07-13
申请人： Arthur R. Marriott
发明人： Arthur R. Marriott
IPC分类号： A61B5/0424 , A61B5/053
CPC分类号： A61B5/0535 , A61B5/0424
摘要： A method and apparatus for use with medical electrode systems that sense the integrity of lead connections and patient transthoracic impedance is provided. In an ECG electrode application, a carrier circuit (12) produces two carrier signals (S.sub.C1 and S.sub.C2) that are out of phase with each other. The S.sub.C1 signal is applied to an RA lead through a terminating impedance (Z1). The S.sub.C2 signal is applied to LA, LL and V leads through terminating impedances (Z2, Z3, and Z4). Each of the S.sub.C1 and S.sub.C2 carrier signals comprises a lead impedance frequency component (S.sub.LI) and an impedance respiration frequency component (S.sub.IR). First stage amplifiers (A1, A2, and A3) located in an ECG preamplifier (13) amplify the difference between a lead voltage on the RA lead (V.sub.RA) and lead voltages on the LA, LL, and V leads (V.sub.LA, V.sub.LL and V.sub.V). High pass filters (F1, F2 and F3) remove patient ECG signals from the outputs of A1, A2 and A3 to produce first stage output voltages (V.sub.1, V.sub.2 and V.sub.5). The V.sub.1, V.sub.2 and V.sub.5 voltages are demodulated by a demodulator circuit (18). Lead impedance demodulators (DM1, DM2 and DM3) are clocked by a lead impedance control signal (S.sub.A) that has the same frequency as the S.sub.LI component so that the outputs of DM1, DM2 and DM3 are lead impedance-related voltages (V.sub.L1, V.sub.L2 and V.sub.L5). V.sub.2 is also demodulated by an impedance respiration demodulator (DM4). DM4 is clocked by an impedance respiration control signal (S.sub.B) that has the same frequency as the S.sub.IR component so that the output of DM4 is a transthoracic impedance-related voltage V.sub.T. V.sub.T is amplified by an operational amplifier (OA10) to produce an impedance respiration-related voltage (V.sub.R). The ECG preamplifier (13) and the demodulator circuit (18) include fast DC restoration circuits (66, 68, 70 and 71) that use switched capacitor integrators (76) to restore ECG outputs (V.sub.E1, V.sub.E2, and V.sub.E5) and the V.sub.R voltage to nominal values when a DC offset has occurred.

你已经成功收藏专利！

检索式保存成功!

IPRDB

热门服务

关于我们

友情链接

联系方式