BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention pertains to stents that are placed inside a blood vessel, canal, or duct of a patient to aid healing or relieve an obstruction, and in particular, to a system and method for wirelessly and passively powering and/or interrogating an implanted stent using a touch probe assembly. The present invention also pertains to a wirelessly and passively powered power meter for use with implanted stents.

2. Description of the Related Art

Atherosclerosis is a disease described by the accumulation of plaque in arterial walls. This plaque build-up results in narrowing of the arteries. The disease leads to diminished blood flow through the artery and in some cases total loss of flow. Depending on the location of the diseased artery, obstruction of flow limits or eliminates the blood supply to organs, limbs, or other parts of the body. Heart attack, stroke, limb amputation, and even death are possibilities stemming from atherosclerosis.

Atherosclerosis affecting arteries in the lower-limbs is called Peripheral Artery Disease (PAD). PAD is often asymptomatic. Upwards of 80% of sufferers do not show symptoms. Based on patient medical history or symptoms, one of several methods may be employed to detect PAD. These methods include the ankle-brachial index, pulse volume recording, and duplex imaging studies using vascular ultrasound, all of which are non-invasive. If a severe blockage is detected (i.e., stenosis), surgical intervention involving balloon dilation angioplasty of the inner arterial lumen or placement of a medical device called a stent is needed to reintroduce blood flow through the diseased locations. Despite the surgical intervention, the likelihood of restenosis (i.e., re-narrowing of the inner arterial lumen due continued build-up of atheromatous plaque) is high, thereby requiring the patient to comply with quarterly or biannual hospital visits to detect blockages, which may be expensive, such as in the case of duplex studies.

A stent is a hollow mesh tube deployed at the diseased location of an artery to maintain inner lumen diameter for unobstructed blood flow. The stent starts as a collapsed mesh tube, which is then deployed using an angioplasty balloon, causing it to expand and press outwards on the inner lumen. Compared with only angioplasty balloon treatment of a diseased vessel, atherosclerotic arteries in the torso (i.e., coronary arteries, iliac arteries, etc.) have benefited greatly from revascularization with stents. The prevalence of stents in the torso has led to the development of many smart stents, which wirelessly (i.e., via far field telemetry) report the degree of restenosis, precluding the need for patient hospital visits, potentially giving rise to patient compliance and saving costs to hospitals and third party insurers.

SUMMARY OF THE INVENTION

In one embodiment, a method of powering a stent apparatus implanted in the body of a patient is provided, wherein the stent apparatus includes at least one stent member functioning as an antenna and an electronics module coupled to the at least one stent member. The method includes generating an RF signal using a reader device having a touch probe, providing the RF signal to the electronics module of the stent apparatus through a near-field electrical connection not over an air interface between the touch probe and the at least one stent member, converting the RF signal provided to the electronics module to DC power, and using the DC power to power the electronics module.

In another embodiment, a system for powering an implantable device is provided. The system a stent apparatus structured to be implanted in the body of a patient, wherein the stent apparatus includes at least one stent member functioning as an antenna and an electronics module coupled to the at least one stent member. The electronics module includes energy harvesting circuitry. The system further includes a reader device having a touch probe. The reader device is structured to generate an RF signal and provide the RF signal to the electronics module of the stent apparatus through a near-field electrical connection not over an air interface between the touch probe and the at least one stent member. The energy harvesting circuitry is structured to convert the RF signal provided to the electronics module to DC power, and the electronics module is structured to be powered by the DC power.

In still another embodiment, a method of interrogating a stent apparatus implanted in the body of a patient is provided, wherein the stent apparatus includes at least one stent member functioning as an antenna and an electronics module coupled to the at least one stent member. The method includes generating an RF signal using a reader device having a touch probe, providing the RF signal to the electronics module of the stent apparatus through a near-field electrical connection not over an air interface between the touch probe and the at least one stent member, and, in response to the RF interrogation signal being provided to the electronics module, receiving information from the electronics module in the reader device through the near-field electrical connection between the touch probe and the at least one stent member.

In yet another embodiment, a system for interrogating an implantable device is provided. The system includes a stent apparatus structured to be implanted in the body of a patient, wherein the stent apparatus includes at least one stent member functioning as an antenna and an electronics module coupled to the at least one stent member. The system further includes a reader device having a touch probe, the reader device being structured to generate an RF signal and provide the RF signal to the electronics module of the stent apparatus through a near-field electrical connection not over an air interface between the touch probe and the at least one stent member. The electronics module is structured to, in response to the RF signal, cause information to be provided to the reader device through the near-field electrical connection between the touch probe and the at least one stent member.

In still another embodiment, an implantable stent apparatus power meter is provided that includes at least one stent member structured to be implanted in a patient and structured to function as an antenna, and an electronics module coupled to the at least one stent member. The electronics module includes a programmable oscillator, wherein the programmable oscillator is structured to generate an oscillating signal that is proportional to an amount of AC power received by the implantable stent apparatus power meter through the at least one stent member, and wherein the electronics module is structured to cause information based on the oscillating signal to be communicated from the implantable stent apparatus using the at least one stent member.

In still a further embodiment, a system for regulating AC power provided to an implantable device is provided. The system includes an antenna and an electronics module forming a part of the implantable device, wherein the antenna is coupled to the electronics module and is structured to receive the AC power. The electronics module includes a programmable oscillator, wherein the programmable oscillator is structured to generate an oscillating signal that is proportional to a magnitude of the AC power received by the implantable device through the antenna, and wherein the electronics module is structured to cause information based on the oscillating signal to be communicated from the implantable device using the antenna. The system further includes a reader device structured to generate the AC power and receive the information from the implantable device, wherein the reader device implements a control loop configured to adjust the magnitude of the AC power based on the information.

In another embodiment, a method for regulating AC power provided to an implantable device is provided. The method includes generating the AC power in a reader device, transmitting the AC power from the reader device and causing the AC power to be received in the implantable device, wherein in response to receiving the AC power the implantable device generates an oscillating signal that is proportional to a magnitude of the AC power received by the implantable device, and receiving information based on the oscillating signal in the reader device and adjusting the magnitude of the AC power based on the information.

In yet a further embodiment, an RE reader device is provided that includes a radio component structured to generate and transmit an AC signal to an implantable device, wherein in response to receiving the AC signal the implantable device generates an oscillating signal that is proportional to a magnitude of the AC signal received by the implantable device wherein the radio component is further structured to receive information based on the oscillating signal from the implantable device, and a control system structured adjust the magnitude of the AC signal based on the information.

