Portable data acquisition unit

• US 5,224,485 A
• Filed: 05/28/1991
• Issued: 07/06/1993
• Est. Priority Date: 05/28/1991
• Status: Expired due to Term

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Powers, Daniel J., Saltzstein, William E., Galen, Peter M., Osborne, Jeffrey C., Hart, Susan R.
• Primary Examiner(s): Cohen, Lee S.
• Assistant Examiner(s): GILBERT, SAMUEL G
• Application Number:
  US07/706,139
• Time in Patent Office: 770 Days
• Field of Search: 128/696, 128/710, 128/709, 128/903, 364/413.06, 340/870.13, 340/825.06, 370/112
• US Class Current: 600/508
• CPC Class Codes: A61B 2560/045 with a separable interface unit, e.g. for communication
• CPC Class Codes: A61B 5/333 Recording apparatus specially adapted therefor

Abstract

A portable data acquisition unit which features a sample order register which sets addresses in a multiplexer unit allowing one out of many electrical signals connected to the multiplexer to pass through at one time. The selected electrical signal is a sample which is transmitted to an A-to-D converter so that a digital signal is generated and passed to a communications port and then to a remote host device. A clock pulse increments the next address in the sample order list to the multiplexer to establish the next signal sample to be transmitted to the host device. At the host device, the original electrical signals may be reconstituted. For example, the electrical signals may be physiological signals derived from transducers associated with an EKG. The host device may be a remote EKG apparatus.

Claims

1. A data acquisition unit for receiving analog signals from transducers comprising,

a portable terminal block terminating a plurality of wire leads for carrying analog signals from the transducers,

a volatile sample order register means in said terminal block containing a sample order, the sample order listing a sequence for sampling said plurality of wire leads,

a multiplexer in said terminal block having as an input said plurality of wire leads, each of the wire leads having an address, the multiplexer having an output,

logic means in said terminal block connected between the sample order register means and the multiplexer for associating the sample order to particular wire leads,

analog-to-digital converter means in said terminal block connected to the multiplexer for receiving the multiplexer output and providing a digital signal, and

a communications port means in said terminal block connected to the analog-to-digital converter means for receiving the digital signal and providing an output signal onto a communications channel and for receiving a new sample order for the sample order register means.

2. This apparatus of claim 1 wherein said sample order register means comprises a random access memory adapted to contain the sample order and a sequencer which reads the sample order in sequence.

3. The apparatus of claim 2 wherein said sample order register means further comprises command decode logic.

4. The apparatus of claim 2 wherein said sequencer is connected to a clock.

5. The apparatus of claim 1 wherein said multiplexer comprises a pair of multiplexer devices.

6. The apparatus of claim 1 wherein said terminal block has hand-holdable size dimensions.

7. The apparatus of claim 1 wherein said communications port means is a serial port.

8. The apparatus of claim 1 wherein said communications channel is a two-way channel having send and receive sub-channels.

9. The apparatus of claim 8 wherein said receive sub-channel carries preselected sample order signals from a remote signal source.

10. A method of operating a data acquisition unit, comprising the steps of:

providing a terminal with a number of wire lead inputs, transmitting a list of wire leads to be sampled in a particular sequence in the terminal from a remote location, the list having an order,

outputting sampled signals from the terminal in accord with the order of the list, and

changing the order of the list by providing a new list.

11. A data acquisition unit for providing to a host a series of digital signals, where each one of the digital signals corresponds to an analog signal present on a respective one of a plurality of wire leads, and where the series proceeds in a sequence selected by the host, the data acquisition unit comprising:

sample order register means for reading from the host a list of numbers representing the sequence, for storing the list of numbers, and for serially writing the numbers in the list, where each number in the list corresponds to one of the wire leads, the sample order register means including means for reading from the host a new list of numbers representing a new sequence;

multiplexer means, receiving the numbers from the sample order register means, and having as inputs said plurality of wire leads, for, in response to receiving each number, providing as an output an analog signal corresponding to the analog signal present on the wire lead corresponding to the number;

analog-to-digital converter means connected to the multiplexer means for receiving the output signal of the multiplexer means and outputting a corresponding digital signal; and

communication port means connected to the output of the analog-to-digital converter means for receiving said digital signal and outputting said digital signal to said remote host.