Multi-channel electrophysiologic signal data acquisition system on an integrated circuit

• US 7,896,807 B2
• Filed: 10/28/2005
• Issued: 03/01/2011
• Est. Priority Date: 10/29/2004
• Status: Expired due to Fees

• Current Assignee: Worcester Polytechnic Institute
• Original Assignee: Worcester Polytechnic Institute
• Inventors: McNeill, John A., Michalson, William R., Clancy, Edward A.
• Primary Examiner(s): Hindenburg; Max
• Assistant Examiner(s): Foreman; Jonathan M
• Application Number:
  US11/262,493
• Publication Number:
  US 20060173364A1
• Time in Patent Office: 1,950 Days
• Field of Search: 600/300, 600/301, 600/323, 600/485, 128/920
• US Class Current: 600/300
• CPC Class Codes: A61B 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: A61B 5/30 Input circuits therefor
• CPC Class Codes: A61B 5/305 Common mode rejection
• CPC Class Codes: A61B 5/307 specially adapted for particular uses
• CPC Class Codes: A61B 5/369 Electroencephalography [EEG] devices for psychotechnics A61B5/16
• CPC Class Codes: A61B 5/389 Electromyography [EMG]
• CPC Class Codes: A61B 5/398 Electrooculography [EOG], e.g. detecting nystagmus; Electroretinography [ERG]
• CPC Class Codes: A61B 5/7242 using integration
• CPC Class Codes: G16H 40/63 for local operation

Abstract

A physiologic data acquisition system includes an analog input, a sigma-delta front end signal conditioning circuit adapted to subtract out DC and low frequency interfering signals from and amplify the analog input before analog to digital conversion. The system can be programmed to acquire a selected physiologic signal, e.g., a physiologic signal characteristic of or originating from a particular biological tissue. The physiologic data acquisition system may include a network interface modulating a plurality of subcarriers with respective portions of an acquired physiologic signal. A receiver coupled to the network interface can receive physiologic data from, and send control signals and provide power to the physiologic data acquisition system over a single pair of wires. The network interface can modulate an RF carrier with the plurality of modulated subcarriers and transmit the resulting signal to the receiver across a wireless network. An integrated circuit may include the physiologic data acquisition system. Also included are methods for acquiring physiologic data comprising the step of selectively controlling an acquisition circuit to acquire the physiologic signal.

Claims

1. A physiologic data acquisition system, comprising:

a plurality of integrated acquisition circuits, a first integrated acquisition circuit in the plurality of integrated acquisition circuits including a plurality of acquisition channels, each acquisition channel being programmable to acquire a signal from an independently selected physiological source, a first acquisition channel in the plurality of acquisition channels including;

an analog input;

a sigma-delta front end signal conditioning circuit; and

an output;

a digital multiplexer coupled to each acquisition channel in the plurality of acquisition channels, the digital multiplexer combining a plurality of digital signals into a serial data stream;

a network interface coupled to the digital multiplexer, the network interface modulating a plurality of subcarriers with respective portions of the serial data stream; and

a receiver networked to the integrated acquisition circuits that receives a plurality of serial data streams from the respective integrated acquisition circuits, the receiver sending a plurality of control signals to each respective integrated acquisition circuit and receiving the plurality of serial data streams from each respective integrated acquisition circuit over a single pair of wires.

2. The system of claim 1, wherein the physiologic signal is an electrophysiologic signal.

3. The system of claim 2, wherein the electrophysiologic signal originates in a tissue selected from heart, brain, skeletal muscle, peripheral nerve, eye, and smooth muscle of the digestive system.

4. The system of claim 1, wherein the physiologic signal relates to blood pressure or blood oxygenation.

5. The system of claim 1, wherein the physiologic signal is light reflected from a physiologic substance.

6. The system of claim 1, wherein the sigma-delta front end signal conditioning circuit comprises a bandpass filter and an amplifier.

7. The system of claim 1, wherein the first integrated acquisition circuit further comprises the digital multiplexer.

8. The system of claim 1, wherein the first integrated acquisition circuit further comprises the network interface.

9. The system of claim 1, wherein each integrated acquisition circuit comprises a data output bandpass filter and a control input bandpass filter corresponding respectively to a data input bandpass filter and a control output bandpass filter comprised by the receiver, the receiver receiving the plurality of serial data streams from each respective integrated acquisition circuit at a data frequency corresponding to the data bandpass filters, and the receiver controlling each respective integrated acquisition circuit at a control frequency corresponding to the control bandpass filters.

10. The system of claim 1, wherein the receiver further provides power to each integrated acquisition circuit over the single pair of wires.

11. The system of claim 1, wherein each acquisition channel includes a respective sigma-delta front end signal conditioning circuit that passband filters each respective analog input signal.

12. The system of claim 1, wherein each acquisition channel includes a respective sigma-delta front end signal conditioning circuit that digitizes each respective analog input signal.

13. A physiologic data acquisition system, comprising:

a plurality of integrated acquisition circuits, a first integrated acquisition circuit in the plurality of integrated acquisition circuits including a plurality of acquisition channels, each acquisition channel being programmable to acquire a signal from an independently selected physiological source, a first acquisition channel in the plurality of acquisition channels including an analog input, a sigma-delta front end signal conditioning circuit, and an output;

a digital multiplexer coupled to each acquisition channel in the plurality of acquisition channels, the digital multiplexer combining a plurality of digital signals into a serial data stream;

a network interface coupled to the digital multiplexer, the network interface modulating a plurality of subcarriers with respective portions of the serial data stream; and

a receiver that receives a plurality of serial data streams from the respective integrated acquisition circuits, the receiver being networked to the integrated acquisition circuits by a wireless network.

14. The system of claim 13, wherein the network interface modulates an RF carrier with the plurality of modulated subcarriers.

15. The system of claim 13, wherein the physiologic signal is an electrophysiologic signal.

16. The system of claim 15, wherein the electrophysiologic signal originates in a tissue selected from heart, brain, skeletal muscle, peripheral nerve, eye, and smooth muscle of the digestive system.

17. The system of claim 13, wherein the physiologic signal relates to blood pressure or blood oxygenation.

18. The system of claim 13, wherein the physiologic signal is light reflected from a physiologic substance.

19. The system of claim 13, wherein the sigma-delta front end signal conditioning circuit comprises a bandpass filter and an amplifier.

20. The system of claim 13, wherein each acquisition channel includes a respective sigma-delta front end signal conditioning circuit that passband filters each respective analog input signal.

21. The system of claim 13, wherein each acquisition channel includes a respective sigma-delta front end signal conditioning circuit that digitizes each respective analog input signal.

22. A physiologic data acquisition system, comprising:

an analog input;

a sigma-delta front end signal conditioning circuit, the sigma-delta front end circuit including a differential difference amplifier that amplifies the difference between a differential voltage of the analog input and a tracking voltage of a subtraction loop, the subtraction loop coupling the differential difference amplifier output to a subtraction input of the differential difference amplifier; and

an output,

the system being programmable to acquire a selected physiologic signal.

23. The system of claim 22, wherein the subtraction loop comprises a quantizer.

24. The system of claim 23, wherein the subtraction loop further comprises at least one programmable integrator.

25. The system of claim 24, wherein a first programmable integrator is coupled between the differential difference amplifier output and the quantizer, and a second programmable integrator is coupled between the differential difference amplifier subtraction input and the quantizer.

26. The system of claim 22, further comprising a reconstruction filter coupled to the differential difference amplifier output.

27. An physiologic data acquisition system, comprising:

means for programming a signal conditioning circuit to condition a signal from a selected physiologic source, the signal being acquired with a first integrated acquisition circuit in a plurality of integrated acquisition circuits, each integrated acquisition circuit including a plurality of acquisition channels, each acquisition channel being programmable to acquire a signal from an independently selected physiological source;

means for digitizing the conditioned signal to produce a plurality of digital signals;

means for combining the plurality of digital signals into a serial data stream;

means for modulating a plurality of subcarriers with respective portions of the serial data stream; and

means for wirelessly receiving a plurality of serial data streams from the respective integrated acquisition circuits.