Source: http://patents.com/us-20120022348.html
Timestamp: 2017-09-24 17:43:17
Document Index: 763353878

Matched Legal Cases: ['Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61', 'Application No. 61']

Application # 2012/0022348. SYSTEMS AND METHODS FOR NON-CONTACT MULTIPARAMETER VITAL SIGNS MONITORING, APNEA THERAPY, SWAY CANCELLATION, PATIENT IDENTIFICATION, AND SUBJECT MONITORING SENSORS - Patents.com
United States Patent Application 20120022348
Droitcour; Amy ; et al. January 26, 2012
SYSTEMS AND METHODS FOR NON-CONTACT MULTIPARAMETER VITAL SIGNS MONITORING, APNEA THERAPY, SWAY CANCELLATION, PATIENT IDENTIFICATION, AND SUBJECT MONITORING SENSORS
Inventors: Droitcour; Amy; (San Francisco, CA) ; Vergara; Alexander; (Honolulu, HI) ; Shing; Tommy; (Honolulu, HI) ; El Hourani; Charles; (Honolulu, HI) ; Nakata; Robert; (Honolulu, HI) ; Mostafanezhad; Isar; (Honolulu, HI) ; Miyasato; Scott; (Mililani, HI)
Assignee: KAI MEDICAL, INC.
Serial No.: 108795
Current U.S. Class: 600/323; 600/407; 600/484; 600/528; 600/538
Class at Publication: 600/323; 600/484; 600/538; 600/407; 600/528
International Class: A61B 5/0205 20060101 A61B005/0205; A61B 5/08 20060101 A61B005/08; A61B 6/00 20060101 A61B006/00; A61B 5/1455 20060101 A61B005/1455; A61B 5/087 20060101 A61B005/087
[0001] This application claims the benefit under 35 U.S.C. .sctn.119(e) of U.S. Provisional Application No. 61/345,065 (Atty. Docket No. KAI-00084), filed on May 14, 2010, titled "Integration of Radar-based Respiratory Measurement or Monitoring with Multi-parameter Patient Monitoring and/or Multi-parameter Vital Signs Measurement Systems"; U.S. Provisional Application No. 61/345,070 (Atty. Docket No. KAI-00085), filed on May 15, 2010, titled "Methods for Sway Cancellation for Non-Contact Measurement of Cardiopulmonary Motion"; U.S. Provisional Application No. 61/370,457 (Atty. Docket No. KAI-00086), filed on Aug. 4, 2010, titled "Patient Identification in Conjunction With a Remote Vital Sign Sensing Radar System". This application also claims the benefit of priority of International Application No. PCT/US11/36543 (Atty. Docket No. KSENS.084WO), filed on May 13, 2011, titled "Systems and Methods for Non-Contact Multiparameter Vital Signs Monitoring, Apnea Therapy, Sway Cancellation, Patient Identification, and Subject Monitoring Sensors". Each of the foregoing applications is incorporated herein by reference in its entirety. This application also incorporates by reference in their entireties all of the following: U.S. application Ser. No. 12/575,447 (Atty. Docket No. KSENS.100CP1), filed on Oct. 7, 2009, titled "Non-Contact Physiologic Motion Sensors and Methods For Use;" U.S. application Ser. No. 12/418,518 (Atty. Docket No. KSENS.100A), filed on Apr. 3, 2009, titled "Non-Contact Physiologic Motion Sensors and Methods For Use;" U.S. Provisional Application No. 61/072,983 (Atty. Docket No. KSENS.021PR), filed on Apr. 3, 2008, titled "Doppler Radar System for Local and Remote Respiration Signals Monitoring"; U.S. Provisional Application No. 61/072,982 (Atty. Docket No. KSENS.023PR), filed on Apr. 3, 2008, titled "Method for Detection of Cessation of Breathing"; U.S. Provisional Application No. 61/123,017 (Atty. Docket No. KSENS.024PR), filed on Apr. 3, 2008, titled "Method for Detection of Motion Interfering with Respiration"; U.S. Provisional Application No. 61/123,135 (Atty. Docket No. KSENS.025PR), filed on Apr. 3, 2008, titled "Method for Detection of Presence of Subject"; U.S. Provisional Application No. 61/125,021 (Atty. Docket No. KSENS.028PR), filed on Apr. 21, 2008, titled "Non-contact Spirometry with a Doppler Radar"; U.S. Provisional Application No. 61/125,019 (Atty. Docket No. KSENS.029PR), filed on Apr. 21, 2008, titled "Monitoring Physical Activity with a Physiologic Monitor"; U.S. Provisional Application No. 61/125,018 (Atty. Docket No. KSENS.030PR), filed on Apr. 21, 2008, titled "Non-contact Method for Calibrating Tidal Volume Measured with Displacement Sensors"; U.S. Provisional Application No. 61/125,023 (Atty. Docket No. KSENS.032PR), filed on Apr. 21, 2008, titled "Use of Empirical Mode Decomposition to Extract Physiological Signals from Motion Measured with a Doppler Radar"; U.S. Provisional Application No. 61/125,027 (Atty. Docket No. KSENS.033PR), filed on Apr. 21, 2008, titled "Use of Direction of Arrival and Empirical Mode Decomposition Algorithms to Isolate and Extract Physiological Motion Measured with a Doppler Radar"; U.S. Provisional Application No. 61/125,022 (Atty. Docket No. KSENS.034PR), filed on Apr. 21, 2008, titled "Data Access Architectures for Doppler Radar Patient Monitoring Systems"; U.S. Provisional Application No. 61/125,020 (Atty. Docket No. KSENS.035PR), filed on Apr. 21, 2008, titled "Use of Direction of Arrival Algorithms to Isolate and Separate Physiological Motion Measured with a Doppler Radar"; U.S. Provisional Application No. 61/125,164 (Atty. Docket No. KSENS.036PR), filed on Apr. 22, 2008, titled "Biometric Signature Collection Using Doppler Radar System"; U.S. Provisional Application No. 61/128,743 (Atty. Docket No. KSENS.037PR), filed on May 23, 2008, titled "Doppler Radar Based Vital Signs Spot Checker"; U.S. Provisional Application No. 61/137,519 (Atty. Docket No. KSENS.039PR), filed on Jul. 30, 2008, titled "Doppler Radar Based Monitoring of Physiological Motion Using Direction of Arrival"; U.S. Provisional Application No. 61/137,532 (Atty. Docket No. KSENS.040PR), filed on Jul. 30, 2008, titled "Doppler Radar Respiration Spot Checker with Narrow Bean Antenna Array"; U.S. Provisional Application No. 61/194,838 (Atty. Docket No. KSENS.041PR), filed on Sep. 29, 2008, titled "Doppler Radar-Based Body Worn Respiration Sensor"; U.S. Provisional Application No. 61/194,836 (Atty. Docket No. KSENS.042PR), filed on Sep. 29, 2008, titled "Wireless Sleep Monitor Utilizing Non-Contact Monitoring of Respiration Motion"; U.S. Provisional Application No. 61/194,839 (Atty. Docket No. KSENS.043PR), filed on Sep. 29, 2008, titled "Continuous Respiratory Rate and Pulse Oximetry Monitoring System"; U.S. Provisional Application No. 61/194,840 (Atty. Docket No. KSENS.044PR), filed on Sep. 29, 2008, titled "Separation of Multiple Targets' Physiological Signals Using Doppler Radar with DOA Processing"; U.S. Provisional Application No. 61/194,848 (Atty. Docket No. KSENS.045PR), filed on Sep. 30, 2008, titled "Detection of Paradoxical Breathing with a Doppler Radar System"; U.S. Provisional Application No. 61/196,762 (Atty. Docket No. KSENS.046PR), filed on Oct. 17, 2008, titled "Monitoring of Chronic Illness Using a Non-contact Respiration Monitor"; U.S. Provisional Application No. 61/200,761 (Atty. Docket No. KSENS.047PR), filed on Dec. 2, 2008, titled "Detection of Paradoxical Breathing with a Paradoxical Breathing Indicator with a Doppler Radar System"; U.S. Provisional Application No. 61/200,876 (Atty. Docket No. KSENS.048PR), filed on Dec. 3, 2008, titled "Doppler Radar Based Monitoring of Physiological Motion Using Direction of Arrival and An Identification Tag"; U.S. Provisional Application No. 61/141,213 (Atty. Docket No. KSENS.049PR), filed on Dec. 29, 2008, titled "A Non-Contact Cardiopulmonary Sensor Device for Medical and Security Applications"; U.S. Provisional Application No. 61/204,881 (Atty. Docket No. KAI-00050), filed on Jan. 9, 2009, titled "Doppler Radar Based Continuous Monitoring of Physiological Motion"; U.S. Provisional Application No. 61/204,880 (Atty. Docket No. KAI-00051), filed on Jan. 9, 2009, titled "Doppler Radar Respiration Spot Checker with Narrow Beam Antenna Array"; U.S. Provisional Application No. 61/206,356 (Atty. Docket No. KAI-00052), filed on Jan. 30, 2009, titled "Doppler Radar Respiration Spot Check Device with Narrow Beam Antenna Array: Kai Sensors Non-Contact Respiratory Rate Spot Check"; U.S. Provisional Application No. 61/154,176 (Atty. Docket No. KAI-00053), filed on Feb. 20, 2009, titled "A Non-Contact Cardiopulmonary Monitoring Device for Medical Imaging System Applications"; U.S. Provisional Application No. 61/154,728 (Atty. Docket No. KAI-00054), filed on Feb. 23, 2009, titled "Doppler Radar-Based Measurement of Vital Signs for Battlefield Triage"; U.S. Provisional Application No. 61/154,732 (Atty. Docket No. KAI-00055), filed on Feb. 23, 2009, titled "Doppler Radar-Based Measurement of Presence and Vital Signs of Subjects for Home Healthcare"; U.S. Provisional Application No. 61/178,930 (Atty. Docket No. KAI-00057), filed on May 15, 2009, titled "Aiming or Aligning Methods and Indicator Display for a Doppler Radar System;" U.S. Provisional Application No. 61/181,289 (Atty. Docket No. KAI-00058), filed on May 27, 2009, titled "Intermittent Doppler Radar Respiration Spot Check;" U.S. Provisional Application No. 61/184,315 (Atty. Docket No. KAI-00059), filed on Jun. 5, 2009, titled "Doppler Radar Respiration Spot Check with Automatic Measurement Length;" and U.S. Provisional Application No. 61/226,707 (Atty. Docket No. KAI-00060), filed on Jul. 18, 2009, titled "Spiral Antenna for a Contacting Cardiopulmonary Sensor."
[0087] In the system 100, deviation of the phase can be proportional to the chest motion divided by the wavelength of the carrier signal, and the amplitude of the signal may not be significantly affected by chest motion, such that when the phase is plotted in the I/Q plane, the I/Q constellation is distributed along an arc of a circle or a full circle. In embodiments in which the chest motion is small compared to the signal's wavelength, the arc can sweep a small portion of the circle, such that it can be approximated by a line, and the phase can be demodulated through linear methods. Alternatively, if the chest motion is large compared with the carrier signal's wavelength, the I/Q constellation samples can be distributed on a larger arc that cannot be approximated by a line. In some embodiments in which the transceiver operates at approximately 5.8 GHz, when the chest motion due to the respiration is approximately 0.5 cm, the phase deviation due to the chest motion can be approximately 70.degree.; a 70.degree. arc may not be accurately approximated as a line in the complex constellation. In these embodiments, non-linear demodulation based on arctangent function can extract phase information directly from arc-distributed samples.
[0092] In various embodiments, the linear demodulation algorithm can comprise one or more of the following operations: [0093] 1. Compute covariance matrix C.sub.M-1 of the current input frame x as shown in block 901a. [0094] 2. Based on C.sub.M-1 and covariance matrices C.sub.0 to C.sub.M-2 of previous frames, compute an A-matrix as shown in block 901b represented by the equation:
[0094] A = i = 0 M - 1 - .alpha. ( M - 1 - i ) C i ##EQU00001## [0095] In this equation, .alpha. can correspond to a damping factor and can be a positive real number. In various embodiments, the value of .alpha. can range from approximately 0.1 to approximately 0.5. In one embodiment, .alpha. can be approximately 0.2. M can correspond to the number of frames in the buffer and can range from about 2 to 15. In one embodiment, M can be 10. [0096] 3. Find the primary vector or eigenvector v.sub.0 corresponding to the largest primary value or eigenvalue of A as shown in block 901c. [0097] 4. Compute the inner product of v.sub.0 and v.sub.1, where v.sub.1 can represent the eigenvector found in operation 3 when performing the algorithm for the previous input frame as shown in block 901d. [0098] 5. Multiply v.sub.0 by the sign of the inner product found in operation 4 as shown in block 901e. [0099] 6. Project samples of the current input frame x on the eigenvector v.sub.0 calculated in operation 5 to get the demodulated frame as shown in block 902.
[0100] If a target's periodic physiological motion variation is represented by x(t), and the wavelength of the radar signal is represented by .lamda., the quadrature baseband output, assuming balanced channels, can be expressed as:
B ( t ) = A r exp ( * ( .theta. + 4 .pi. .DELTA. x ( t ) .lamda. ) ) + D C ##EQU00002##
[0101] In this equation, DC can be a complex number representing the non-time-varying voltage values of the I and Q channels, .theta. can represent the constant phase shift due to the transceiver architecture and target range, and Ar can represent the amplitude of the baseband signal. From (1), it will be appreciated that if DC, which can come from clutter, intra-circuit reflection, and self-mixing is estimated and removed, the angle deviation, which can be linearly proportional to actual physical motion of a target x(t), can be extracted simply by the arctangent function. However, if the low-frequency or direct-current component of the phase shift caused by x(t) is removed, or if DC is not removed, arctangent demodulation can be more complicated and is not straightforward.
[0106] 1. Mode=1 [0107] a. Compute covariance matrix C.sub.M-1 of the current input frame x.sub.h2 filtered with a first filter having a filter function h2, as shown in block 1201f of FIG. 9B. In some embodiments, the first filter can be a low-pass filter. [0108] b. Using C.sub.M-1 and the covariance matrices C.sub.0 to C.sub.M-2 of previous frames, compute an A-matrix
as shown in block 1201g of FIG. 9B, where M can represent the number of preceding frames to consider and in some embodiments M can be 32. In various embodiments M can be larger or smaller than 32. [0109] c. Find the eigenvector v.sub.o corresponding to the largest eigenvalue of A, as shown in block 1201h of FIG. 9B. [0110] d. Compute the absolute value chd of the inner product of v.sub.0 and v.sub.1, where v.sub.1 is the eigenvector found in operation c when performing the algorithm for the previous input frame, as shown in block 1201i of FIG. 9B. [0111] e. Compute the ratio pc of the largest to the second-largest eigenvalue, as shown in block 1201j of FIG. 9B. [0112] f. Compute the energy e.sub.1 of the input frame x.sub.3 filtered with a second filter having a filter function h3. In various embodiments, the second filter can be a high-pass filter, as shown in block 1201k of FIG. 9B. [0113] g. Compute the average energy per frame e.sub.2 of all M-1 previous input frames x.sub.3 filtered with h3, as shown in block 1201l of FIG. 9B. [0114] h. Compute the ratio detectp=e.sub.1/e.sub.2, as shown in block 1201m of FIG. 9B. [0115] i. If (chd<th1 OR pc<thev1 OR detectp>thp1) AND detectp>thp1d), as shown in block 1201b and 1201c then non-cardiopulmonary motion or other signal interference is detected, switch to Mode=2. In various embodiments th1 can have a value between approximately 0.6 and approximately 1. In various embodiments, thev1 can have a value in the ranging from about 4 to 12. In various embodiments, thp1 can have a value ranging from about 4 to 20. In various embodiments, thp1d can have a value between approximately 0.1 and approximately 0.8.
where C.sub.i can represent a covariance matrix from frame i (frame n being the most recent), as shown in block 1201n of FIG. 9C. [0118] b. Compute a matrix p of eigenvectors as follows, as shown in block 1201p of FIG. 9C:
TABLE-US-00001 [0118] For j = 0 To SeqM { For i = 0 To SeqM { i. m = M - (minM + i - 1) ii. n = M - j iii. .rho..sub.i,j = v.sub.m,n } }
.rho. = [ v M - ( minM - 1 ) , M - 1 v M - ( minM - 1 ) , M - SeqM v M - ( minM - SeqM - 1 ) , M - 1 v M - ( minM - SeqM - 1 ) , M - SeqM ] , ##EQU00005##
where SeqM can be about 5 in some embodiments and can correspond to the number of preceding frames to consider, where minM can represent the number of frames prior to current frame to consider and can be about 8 in some embodiments, where v.sub.m,n can represent the eigenvector corresponding to the largest eigenvalue of A.sub.m,n. [0119] c. Compute the ratio pc.sub.i,M-1 of the largest to the second largest eigenvalue of the matrix A.sub.i,M-1, as shown in block 1201q of FIG. 9C. [0120] d. Find the minimum chd of the absolute value of the inner product of all pairs of v.sub.m,n in .rho., as shown in block 1201r of FIG. 9C. [0121] e. Compute the energy ratio
[0121] .sigma. i = k = 0 N x h 3 i ( k ) / j = i M - 1 k = 0 N x h 3 j ( k ) , ##EQU00006##
where x.sub.h3.sup.i(k) can represent sample k from frame i filtered with h3, as shown in block 1201s of FIG. 9D. [0122] f. If (chd>th2 AND pc.sub.M-(minM-1),M-1>thev2) then non-cardiopulmonary motion and/or other signal interference is indicated to have stopped, switch to Mode=1, as shown in blocks 1201d and 1201e of FIG. 9A. In various embodiments, th2 can have a value between approximately 0.6 and approximately 1. In various embodiments, thev2 can have a value between approximately 4 and approximately 12. [0123] g. Retrospect: Compute 4 indices idx1, idx2, idx3, idx4 as follows, as shown in block 1201t. [0124] idx1: the largest i such that v.sub.M-(minM-1),M-1.sup.Hv.sub.i,M-1<th3. [0125] idx2: the largest i such that v.sub.M-(minM-1),M-2.sup.Hv.sub.i,M-1<th3 [0126] idx3: the largest i such that pc.sub.i,M-1<thev2. [0127] idx4: the largest i such that .sigma..sub.i<thp2. [0128] In various embodiments, th3 can have a value between approximately 0.6 and approximately 1. In various embodiments, thp2 can have a value between approximately 4 and 12. In one embodiment, thp2 can be approximately 5. In one embodiment, th3 can be approximately 0.97. [0129] h. Then, non-cardiopulmonary motion and/or other signal interference is indicated to have stopped during frame index max(idx1, idx2, idx3, idx4), as shown in block 1201u.
Ae.sup.j.theta., where A can represent power and .theta. can represent phase.
[0154] In some embodiments, the complex weight factor can be selected by solving for A and .theta. to minimize undesired signal power for the sum of the front and back signal. In some embodiments, the undesired signal power may be that of a certain bandwidth. In some embodiments, the undesired signal power may be some specific frequency such as that of the swaying motion. In some embodiments, MMSE estimation may be used to solve for A and .theta.. In some embodiments, LSE may be used to solve for A and .theta..
[0159] In some embodiments, as shown in FIG. 15B, one or more of the following operations can be performed on the signals obtained from both of the sensors: [0160] 1. Acquire time synced I and Q signals from both of the sensors. x.sub.i1, x.sub.q1 from sensor 1 and x.sub.i2, x.sub.q2 from sensor 2. [0161] 2. Perform Principal Component Analysis (PCA) on x.sub.i1, x.sub.q1 and call the result D1 [0162] 3. Perform Principal Component Analysis (PCA) on x.sub.i2, x.sub.q2 and call the result D2 [0163] 4. Perform PCA on D1 and D2. Choose the output with the smaller eigen value as a physiological signal and the output with larger eigen value as the sway component.
[0183] Obstructive apnea can be defined as an 80-100% reduction in airflow signal amplitude for a minimum of 10 seconds with continued respiratory effort. The rib cage and abdomen can move out of phase as the patient tries to breathe, but the airway can be blocked. A quadrature Doppler radar system, such as the one described above, can monitor this paradoxical breathing based on the complex constellation due to the target's chest and abdomen motion. Since a human's physiological signal such as breathing is a very narrow band signal (.about.less than 1 KHz) compared to the radar carrier signal, all the reflected signals will be phase modulated on a coherent carrier signal. Therefore, if human body parts, for example the chest and abdomen, are expanding or contracting simultaneously, the received reflecting signals from different paths (reflecting from different body parts) may only shift the phasor of the carrier signal but not the phase modulated narrow band carrier signals. Shift of the phasor of phase modulated narrow band carrier signals can also occur when different body parts are moving at the same frequency but with different amplitude or phase delay, as is the case in paradoxical breathing. Consequently, in the former case, the shape of the complex plot at the baseband due to the respiration may not change and can form a fraction of a circle (an arc) which can be similar to the one from the a single source, while in the latter case the phasor of the baseband signal changes during the periodic motion (such as breathing), resulting in distortion of the complex constellation. This fact can be used to detect paradoxical breathing.
Cost ( input ) = 1 v .times. 2 .pi. .intg. x 1 x 2 exp ( - ( input - m ) 2 2 .times. v 2 ) x , ##EQU00007##
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