Apparatus and methods for wireless communication via electrical pulses conducted by the interstitial tissues of the body for an active implantable medical device
An active implantable medical device having wireless communication of data via electrical pulses conducted by the interstitial tissues of the body. This device ( 12, 14 ) includes a pair of electrodes ( 22, 24 ) and generates pulse trains consisting of a series of electrical pulses applied to the electrodes. The pulse train is modulated by digital information (data) that is produced by the device. A regulated current or voltage source ( 42 ) is used to generate ( 44, 48 ) current or voltage pulses to form the pulse train. Each current or voltage pulse is a biphasic pulse comprising a positive and negative alternation. The biphasic current or voltage modulated by the digital information, is injected between the electrodes ( 22, 24 ) and wirelessly communicated.
1. An active implantable medical device, comprising means for wireless intracorporeal communication with at least one other active implantable medical device via electrical signals conducted by the interstitial tissues of a patient's body comprising:
Means for providing digital information to be communicated;
at least one pair of electrodes
Means for generating a pulse train containing a succession of electrical pulses, said generator means comprising a regulated current source, wherein said pulse train comprises a train of biphasic current pulse produced by said regulated current source, each biphasic pulse comprising a positive and a negative alteration;
Means for modulating the pulse train by said digital information; and
Means for injecting the modulated pulse train between said at least one pair of electrodes;
wherein the modulation means further comprises means for modulating a temporal interval between the pairs of consecutive biphasic current pulses of the biphasic pulse train.
2. The device of claim 1 , wherein each positive and negative alternation of a biphasic current pulse comprises a square wave shape.
3. The device of claim 1 , wherein the negative alternation of the biphasic current pulse follows the positive alternation of that pulse, or vice versa.
4. The device of claim 1 , wherein the negative and positive alternations of said biphasic current pulse are symmetrical.
5. The device of claim 1 , wherein said pulse train comprises an alternation of the sequence of polarities of the alternations from one biphasic pulse to the next, so that a biphasic pulse whose positive alternation precedes the negative alternation is followed by a biphasic pulse whose negative alternation precedes the positive alternation, and vice versa.
6. The device of claim 1 , wherein the modulation means further comprises means for modulating the pulse width of successive biphasic current pulses of the pulse train.
7. The device of claim 1 , wherein the modulation means further comprises means for modulating an amplitude of the successive biphasic current pulses of the pulse train.
8. The device of claim 1 , wherein the biphasic current pulse has a duration between 0.1 and 30 μs.
9. The device of claim 8 , wherein the biphasic current pulse has a duration of 0.5 μs.
10. The device of claim 1 , wherein the biphasic current pulse has a recurrence period of between 2 μs and 2 ms.
11. The device of claim 10 , wherein the recurrence period is 2 μs.
12. The device of claim 1 , wherein the positive and negative alternation of the current pulse each has an amplitude of between 30 μA and 20 mA.
13. The device of claim 12 , wherein the amplitude is 10 mA.