Insertable sensor assembly having a coupled inductor communicative system

• US 20050038331A1
• Filed: 08/14/2003
• Published: 02/17/2005
• Est. Priority Date: 08/14/2003
• Status: Abandoned Application

• Current Assignee: Isense Corporation
• Original Assignee: Isense Corporation
• Inventors: Birck, Jonathan D., Silaski, Grayson
• Application Number:
  US10/640,978
• Publication Number:
  US 20050038331A1
• Time in Patent Office: Days
• US Class Current: 600/347
• CPC Class Codes: A61B 2560/0219 of externally powered implanted units
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors

Abstract

A sensing system for determining the concentration of an analyte inside an animal body. The system includes an in vivo portion that is adapted to reside inside the animal body and that includes a sensing element that produces a sensing signal. In addition, a wearable ex vivo portion is physically attached to the in vivo portion. The ex vivo portion includes a first inductor that is adapted to receive a varying electro-magnetic signal and that has a pair of terminals. A variable load assembly presents a load across the pair of terminals and varies the load in response to the sensing signal. Also, an electronic monitoring unit is physically separate from the ex vivo portion and includes a second inductor, which is magnetically coupled to the first inductor and is adapted to transmit a varying electro-magnetic signal and to detect changes in load across the terminals of the first inductor.

Claims

1. A sensing system for determining the concentration of an analyte inside an animal body, said system including:

(a) an in vivo portion, adapted to reside inside said animal body and including a sensing element that produces a sensing signal;

(b) a wearable ex vivo portion physically attached to said in vivo portion, including;

(i) a first inductor adapted to receive a varying electromagnetic signal and having a pair of terminals; and

(ii) a variable load assembly presenting a load across said pair of terminals and varying said load in response to said sensing signal; and

(c) an electronic monitoring unit that is physically separate from said ex vivo portion and includes a second inductor, which is magnetically coupled to said first inductor and adapted to transmit a varying electromagnetic signal and to detect changes in load across said terminals of said first inductor.

2. The biological sensing system of claim 1, wherein said ex vivo portion also includes a battery.

3. The biological sensing system of claim 1, wherein said battery biases said sensing element.

4. The biological sensing system of claim 1, wherein said ex vivo portion also includes memory to store measurement values from said in vivo portion.

5. In a biological sensing system that includes an in vivo portion, adapted to reside inside a patient, an ex vivo portion physically attached to the in vivo portion and having an antenna, and an electronic monitoring unit that is physically separate from, but in wireless communication by way of electromagnetic signals with the ex vivo portion, an improvement comprising:

(a) electronic memory adapted to store memory contents in said ex vivo portion; and

(b) a transmitter in said electronic monitoring unit adapted to transmit a said electromagnetic signal to said ex vivo portion, directing said ex vivo portion to transmit at least a portion of said memory contents to said electronic monitoring unit.

6. The biological sensing system of claim 5 wherein said electronic monitoring unit includes a manual actuator adapted to permit a patient to enter a request for data and wherein said transmitter transmits a said electromagnetic signal requesting data to said ex vivo portion in response thereto.

7. The biological sensing system of claim 5 wherein said ex vivo portion is able to effectively transmit to said electronic monitoring unit by sequentially changing impedance across said antenna.