Sensor/lead systems for use with implantable medical devices

• US 8,388,670 B1
• Filed: 01/16/2007
• Issued: 03/05/2013
• Est. Priority Date: 01/16/2007
• Status: Active Grant

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Inventors: Zou, Yongning, Vogel, Alan B., Sorensen, Chris, Hamilton, James B., Albu, Ryan
• Primary Examiner(s): Bertram, Eric D
• Assistant Examiner(s): Dinga, Roland
• Application Number:
  US11/623,663
• Time in Patent Office: 2,240 Days
• Field of Search: 607/122
• US Class Current: 607/112
• CPC Class Codes: A61B 2562/0204 Acoustic sensors
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 2562/0247 Pressure sensors
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/029 Measuring or recording blood output from the heart, e.g. minute volume A61B8/065 takes precedence
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/6869 Heart
• CPC Class Codes: A61B 5/7285 for synchronising or triggering a physiological measurement or image acquisition with a physiological event or waveform, e.g. an ECG signal A61B6/5205, A61B6/541, A61B8/5207, A61B8/543 take precedence
• CPC Class Codes: A61N 1/056 Transvascular endocardial electrode systems
• CPC Class Codes: A61N 1/368 comprising more than one electrode co-operating with different heart regions A61N1/3622, A61N1/3627 take precedence
• CPC Class Codes: A61N 1/3704 Circuits specially adapted therefor, e.g. for sensitivity control
• CPC Class Codes: A61N 1/39622 Pacing therapy

Abstract

Techniques are provided for equipping sensing/pacing leads with physiological sensors without requiring additional conductors within the leads. In a bipolar lead example for use with a pacemaker, a sensor is connected between tip and ring conductors of the lead. The sensor is configured to be activated only in response to enhanced pacing pulse (EPPs) having magnitudes or durations greater than typical pacing pulses or in response to impedance detection pulses (IMPs). In a unipolar example, the sensor is connected to the tip conductor and includes an output terminal on the external housing of the lead for providing a return current path to the pacemaker. The sensor of the unipolar lead is likewise configured to respond only to EPPs or IMPs. In other examples, the sensors are configured to be fitted to the external housing of the lead and to derive power from the lead via electromagnetic induction. Still other examples include actuators rather than sensors.

Claims

1. A lead for use with an implantable medical device for implant within patient tissue, the lead comprising:

a stimulation electrode fitted to be positioned adjacent patient tissue;

a conductor operative to conduct electrical current from the implantable medical device through the lead to the stimulation electrode, the current returning to the implantable medical device along a return conduction path; and

a sensor disposed within the lead and connected between the conductor and the return conduction path so that the sensor and the stimulation electrode are connected in parallel between the conductor and the return path;

wherein the sensor is configured to be activated only in response to enhanced pacing pulses which exceed an activation threshold and wherein the stimulation electrode is configured to be activated only in response to pacing pulses which are below the activation threshold such that current is selectively directed either through the stimulation electrode or through the sensor.

2. The lead of claim 1 wherein the sensor is one or more of a blood oxygen sensor, a pH sensor, a temperature sensor, a blood glucose sensor, an accelerometer, a cardiac output sensor, a contractility sensor, an acoustic sensor and a pressure sensor.

3. The lead of claim 1 wherein the sensor of the lead is an actuator.

4. The lead of claim 3 wherein the actuator is an implantable drug pump.

5. The lead of claim 1 wherein the stimulation electrode is a first electrode and the return conduction path to the implantable medical device is through patient tissue, so that a unipolar lead is provided having a sensor and a first electrode connected in parallel between a conductor within the lead and a return path within patient tissue.

6. The lead of claim 1 wherein the stimulation electrode is a first electrode connected to a first electrode conductor within the lead and wherein the return conduction path includes a second electrode connected to a second electrode conductor within the lead, so that a bipolar lead is provided having a sensor and an electrode pair connected in parallel between a first electrode conductor and a second electrode conductor within the lead.

7. The lead of claim 1 wherein the sensor of the lead is configured to be activated only in response to a voltage exceeding a predetermine threshold voltage, so that any electrical pulses delivered by the implantable medical device at voltages less than that threshold do not activate the sensor.

8. The lead of claim 1 wherein the sensor of the lead is configured to be activated only in response to a pulse having a pulse width exceeding a predetermine threshold width, so that any electrical pulses delivered by the implantable medical device with widths less than that threshold do not activate the sensor.

9. The lead of claim 1 wherein the sensor of the lead is configured to respond to a sequence of electrical pulses delivered by the implantable medical device.

10. The lead of claim 9 wherein the sensor of the lead is a physiological sensor configured to respond to a first pulse by sensing physiological parameters and to respond to a second pulse by transmitting the physiological parameters to the device.

11. The lead of claim 1 wherein the sensor of the leads is a physiological sensor equipped to transmit sensed signals to the implantable medical device via wireless communication.

12. The lead of claim 1 wherein the sensor of the leads is a physiological sensor equipped to transmit sensed signals to the implantable medical device via non-wireless communication along the return conduction path.

13. The lead of claim 1 wherein the physiological sensor is mounted externally to the lead and is equipped to receive power inductively from the lead.