Body worn physiological sensor device having a disposable electrode module

• US 9,877,663 B2
• Filed: 08/16/2016
• Issued: 01/30/2018
• Est. Priority Date: 11/01/2006
• Status: Active Grant

• Current Assignee: Welch Allyn Incorporated
• Original Assignee: Welch Allyn Incorporated
• Inventors: Baker, Steven D., McAdams, Eric T., Welch, James P.
• Primary Examiner(s): Johnson, Nicole F
• Application Number:
  US15/237,719
• Publication Number:
  US 20160354003A1
• Time in Patent Office: 532 Days
• Field of Search: 600509
• CPC Class Codes: A61B 2560/0209 adapted for power saving
• CPC Class Codes: A61B 2560/0214 of power generation or supply
• CPC Class Codes: A61B 2560/0412 Low-profile patch shaped housings
• CPC Class Codes: A61B 2562/0214 Capacitive electrodes
• CPC Class Codes: A61B 2562/182 Electrical shielding, e.g. using a Faraday cage
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/259 using conductive adhesive means, e.g. gels
• CPC Class Codes: A61B 5/274 using snap or button fasteners
• CPC Class Codes: A61B 5/282 Holders for multiple electrodes for introduction into the body A61B5/287
• CPC Class Codes: A61B 5/301 providing electrical separation, e.g. by using isolating transformers or optocouplers
• CPC Class Codes: A61B 5/303 Patient cord assembly, e.g. cable harness
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/68335 including release sheets or liners
• CPC Class Codes: A61B 5/7232 involving compression of the physiological signal, e.g. to extend the signal recording period
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61B 5/746 : Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B

Abstract

A body worn patient monitoring device includes a flexible substrate having a plurality of electrical connections adapted to be coupled to a skin surface to measure physiological signals. The flexible substrate is adapted to be directly and non-permanently affixed to a skin surface of a patient and configured for single patient use. A communication-computation module, removably attached to an upper surface of the flexible substrate, is configured to receive physiological signals from the flexible substrate and includes a microprocessor that is configured to process and analyze the physiological signals. A series of resistive traces screened onto the flexible substrate are configured as at least one series current-limiting resistor to protect the communication-computation module.

Claims

1. A method to improve ECG signal high pass filtering, said method comprising:

providing an ECG monitor having a programmed microprocessor and a plurality of electrical connections to measure patient heartbeat signals;

filtering the measured heartbeat signals with an analog high pass filter having an analog high pass cutoff frequency;

performing a first measurement on the measured heartbeat signals filtered with the analog high pass filter at the analog high pass cutoff frequency;

removing the effects of the analog high pass filter with a digital inverse filter algorithm resulting in substantially unfiltered heartbeat signals;

filtering the substantially unfiltered heartbeat signals digitally using a digital filter having a digital high pass filter cutoff frequency lower than the analog high pass cutoff frequency; and

performing a second measurement on the measured heartbeat signals filtered with the lower digital high pass filter cutoff frequency.

2. The method of claim 1, wherein the step of filtering the measured heartbeat signals with an analog high pass filter comprises the step of filtering the measured signals with an analog high pass filter having a 0.5 Hz analog high pass cutoff frequency, and the step of filtering the substantially unfiltered heartbeat signals digitally comprises the step of filtering the substantially unfiltered heartbeat signals digitally using a digital filter having a digital 0.05 Hz high pass filter cutoff frequency.

3. The method of claim 1, wherein the ECG monitor is part of a body-worn monitoring device, the monitoring device comprising a disposable module having a plurality of electrical connections for coupling to a skin surface, a power source to power the body-worn monitoring device, and a computation-communication module, the body-worn monitoring device being adapted to be directly non-permanently affixed to the skin surface.

4. The method of claim 3, further comprising providing at least one series current-limiting resistor configured to protect the computation-communication module.

5. The method of claim 4, wherein the step of providing the at least one series current-limiting resistor includes the steps of providing resistive traces on a flexible substrate of the body-worn monitoring device.

6. The method of claim 5, further comprising providing an insulating material overlaying the at least one series-limiting resistor to prevent arcing.

7. The method of claim 3, including the step of providing a pacer detection circuit.

8. The method of claim 7, wherein the pacer detection circuit is provided in the computation-communication module.

9. The method of claim 8, wherein the pacer detection circuit is configured to produce an interrupt signal when a pacer event has occurred.

10. The method of claim 9, including the step of determining whether a patient has a pacemaker and only enabling the pacer detection circuit when a pacemaker is present.

11. The method of claim 3, including the step of implementing the high pass filter in software running on a microprocessor in the computation-communication module.

12. The method of claim 9, including the step of self-checking the pacer detection circuit by injecting a simulated pacer pulse into a front end amplifier to simulate the presence of a pacemaker.

13. The method of claim 3, including the step of providing electro-surgical suppression (ESIS) circuits to protect the computation-communication module from external high energy signals.