Method of interference-tolerant transmission of heartbeat signals

• US 5,611,346 A
• Filed: 04/14/1995
• Issued: 03/18/1997
• Est. Priority Date: 08/16/1993
• Status: Expired due to Term

• Current Assignee: Polar Electro Oy
• Original Assignee: Polar Electro Oy
• Inventors: Heikkila, Ilkka, Pietila, Arto
• Primary Examiner(s): Manuel, George
• Assistant Examiner(s): LAYNO, CARL HERNANDZ
• Application Number:
  US08/416,792
• Time in Patent Office: 704 Days
• Field of Search: 128/695, 128/696, 128/903, 607/60
• US Class Current: 600/509
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: Y10S 128/903 Radio telemetry

Abstract

A method of interference-tolerant heartbeat measurement comprises the steps of measuring the person'"'"'s heartbeat signal at a suitable part of the body and transmitting the signal by telemetric transmission from a transmitter to a receiver as a pulse message formed by successive measuring pulses. A transmission interval of at least some pulse signals is proportional to the person'"'"'s measured heartbeat rate. Each measuring pulse is formed of at least two identification pulses (C1 and C2), whereby the time interval (t_x) between the identification pulses corresponds to a specific time interval determined for each transmitter-receiver pair, on the basis of which specific interval the receiver identifies the pulse signals intended for itself.

Claims

1. Method of interference-tolerant heartbeat measurement, said method comprising the steps of:

(a) measuring a person'"'"'s heartbeat signal at a suitable part of said person'"'"'s body;

(b) forming groups of data pulses corresponding to measurements of said heartbeat signal, each of said groups of data pulses including at least first and second identification pulses separated by a first time interval, said first time interval being selected for identification of a transmitter-receiver pair including a transmitter and a receiver;

(c) transmitting said groups of data pulses from said transmitter to said receiver by telemetric transmission said groups of data pulses including at least some pulse signals which are separated by a second time interval, said second time interval being proportional to a heartbeat rate corresponding to said person'"'"'s measured heartbeat signal;

(d) receiving said groups of data pulses in said receiver; and

(e) identifying said groups of data pulses as emanating from said transmitter by means of sensing said first time interval between said first and second identification pulses.

2. Method according to claim 1, wherein:

in step (b), said groups of data pulses include a break pulse followed after a third time interval by the first identification pulse; and

in step (c), break pulses of sucessive groups of said data pulses are separated by said second time interval.

3. Method according to claim 1, wherein:

in steb (b), said groups of data pulses include a break pulse which follows a third time interval after said second identification pulse; and

in step (c), first identification pulses of successive groups of said data pulses are separated by said second time interval.

4. A method in accordance with claim 1, wherein in said transmitting step, said telemetric transmission comprises transmission by magnetic inductive coupling.

5. Method according to claim 1, wherein in step (b), said groups of data pulses include:

a break pulse;

a first measuring pulse following a third time interval after said break pulse; and

a second measuring pulse, which simultaneously is the first identification pulse, following said second time interval after said first measuring pulse.

6. Method according to claim 5, wherein step (c) includes the sub-step of separating said groups of data pulses by a transmission interval which is set to be randomly variable in such a way that the time between the groups of data pulses varies randomly within predetermined limits.

7. A method in accordance with claim 6, wherein said predetermined limits are between 2 and 4 seconds.

8. Method of interference-tolerant heartbeat measurement, said method comprising the steps of:

(a) measuring a person'"'"'s heartbeat signal at a suitable part of said person'"'"'s body;

(b) forming first and second groups of pulses corresponding to at least first and second measurements of said heartbeat signal, each of said groups of pulses including;

(i) a first pulse, said first pulse being a break pulse;

(ii) a second pulse, said second pulse being a measuring pulse, said second pulse following a first time interval after said first pulse, said first time interval being fixed;

(iii) a third pulse, said third pulse being both a measuring pulse and an identification pulse, said third pulse following a second time interval after said second pulse, said second time interval being variable and being proportional to a heartbeat rate corresponding to said person'"'"'s measured heartbeat signal; and

(iv) a fourth pulse, said fourth pulse being an identification pulse, said fourth pulse following a third time interval after said third pulse, said third time interval being fixed and being equal to a specific time interval preselected for identification of a transmitter-receiver pair including a transmitter and a receiver;

(c) transmitting said first and second groups of pulses from said transmitter to said receiver by telemetric transmission, said first and second groups of pulses being separated by a fourth time interval, said fourth time interval being proportional to said heartbeat rate corresponding to said person'"'"'s measured heartbeat signal;

(d) receiving said first and second groups of pulses in said receiver; and

(e) identifying said first and second groups of pulses as emanating from said transmitter by means of sensing said third time interval between said third and fourth pulses of each of said first and second groups of pulses.

9. Method of interference-tolerant heartbeat measurement, said method comprising the steps of:

(a) measuring a person'"'"'s heartbeat signal at a suitable part of said person'"'"'s body;

(b) forming groups of pulses corresponding to measurements of said heartbeat signal, each of said groups of pulses including;

(i) first pulse, said first pulse being a break pulse;

(ii) a second pulse, said second pulse being a first identification pulse, said second pulse following a first time interval after said first pulse;

(iii) a third pulse, said third pulse being a second identification pulse, said third pulse following a second time interval after said second pulse, said second time interval being proportional to a consecutive transmission number or the like; and

(iv) a fourth pulse, said fourth pulse being a third identification pulse, said fourth pulse following a third time interval after said third pulse, said third time interval being equal to a specific time interval selected for identification of a transmitter-receiver pair including a transmitter and a receiver;

(c) transmitting said groups of pulses from said transmitter to said receiver by telemetric transmission, said groups of pulses being separated by a fourth time interval, said fourth time interval being proportional to a heartbeat rate corresponding to said person'"'"'s measured heartbeat signal;

(d) receiving said groups of pulses in said receiver; and

(e) identifying said groups of pulses as emanating from said transmitter by means of sensing said third time interval between said third and fourth pulses of each of said groups of pulses.

10. Method of interference-tolerant heartbeat measurement, said method comprising the steps of:

(a) measuring a person'"'"'s heartbeat signal at a suitable part of said person'"'"'s body;

(b) forming a first specific time interval for a transmitter-receiver pair including a transmitter and a receiver, said first specific time interval of said transmitter-receiver pair being formed by a random operation when said transmitter is started, said receiver being locked to said first specific time interval throughout a time for which said person'"'"'s heartbeat is to be measured for purposes of identifying said transmitter to said receiver;

(c) subsequent to step (b), forming first and second groups of pulses corresponding to at least first and second measurements of said heartbeat signal, each of said groups of pulses including at least first and second identification pulses separated by said first time interval;

(d) transmitting said first and second groups of pulses from said transmitter to said receiver by telemetric transmission, said first and second groups of pulses being separated by a second time interval, at least one of;

(i) said second time interval; and

(ii) a third time interval between pulses within said first and second groups of pulses being proportional to a heartbeat rate corresponding to said person'"'"'s measured heartbeat signal;

(e) receiving said first and second groups of pulses in said receiver; and

(f) identifying said first and second groups of pulses as emanating from said transmitter by means of sensing said first specific time interval between said first and second identification pulses of each of said first and second groups of pulses.

11. Method of interference-tolerant heartbeat measurement, said method comprising the steps of:

(a) measuring a person'"'"'s heartbeat signal at a suitable part of said person'"'"'s body;

(b) forming first and second groups of pulses corresponding to at least first and second measurements of said heartbeat signal, each of said groups of pulses including at least first and second identification pulses separated by a first specific time interval, said first specific time interval being preselected for time-interval-coded identification of a transmitter-receiver pair including a transmitter and a receiver;

(c) transmitting said first and second groups of pulses from said transmitter to said receiver by telemetric transmission, said first and second groups of pulses being separated by a second time interval, at least one of;

(i) said second time interval; and

(ii) a third time interval between pulses within each of said first and second groups of pulses being proportional to a heartbeat rate corresponding to said person'"'"'s measured heartbeat signal and constituting a time-interval-coded representation of said heartbeat rate;

(d) receiving said first and second groups of pulses in said receiver; and

(e) identifying said first and second groups of pulses as emanating from said transmitter by means of sensing said first specific time interval between said first and second identification pulses of each of said first and second groups of pulses.

12. A method in accordance with claim 11, wherein in said transmitting step, said telemetric transmission comprises transmission by magnetic inductive coupling.