Modularized inexpensive detection of cerebral spinal fluid for medical applications
Various examples are provided for disposable medical sensors that can be used for the detection of cerebral spinal fluid. In one example, a medical sensing system includes a disposable sensing unit comprising a functionalized sensing area disposed between electrodes; and a portable sensing unit analyzer including pulse generation circuitry that can generate synchronized gate and drain pulses and a transistor with a gate electrically coupled to one electrode. A gate pulse output of the pulse generation circuitry is electrically coupled to a second electrode and a drain pulse output is electrically coupled to a drain of the transistor. In another example, a method includes providing a sample to a functionalized sensing area, generating synchronized gate and drain pulses for a transistor, the gate pulse provided via the electrodes and functionalized sensing area, and sensing an output of the transistor that is a function of a target concentration of the sample.
1 . A medical sensing system, comprising:
a disposable sensing unit comprising:
a substrate;
first and second electrodes disposed on the substrate; and
a functionalized sensing area disposed between the first and second electrodes on the substrate without a transistor between the first and second electrodes, the functionalized sensing area functionalized with an anti β-2-transferrin antibody; and
a portable sensing unit analyzer comprising:
pulse generation circuitry configured to generate synchronized gate and drain pulses, the first electrode of the disposable sensing unit electrically coupled to a gate pulse output of the pulse generation circuitry; and
a transistor having a drain electrically coupled to a drain pulse output of the pulse generation circuitry, and a gate electrically coupled to the second electrode of the disposable sensing unit.
2 . The medical sensing system of claim 1 , wherein the anti β-2-transferrin antibody is bound to the functionalized sensing area by a binding agent disposed on the first electrode.
3 . The medical sensing system of claim 2 , wherein the binding agent is thioglycolic acid (TGA, HSCH 2 COOH).
4 . The medical sensing system of claim 1 , wherein the first and second electrodes comprise a passivation layer of photoresist.
5 . The medical sensing system of claim 4 , wherein the passivation layer comprises an opening exposing the functionalized sensing area.
6 . The medical sensing system of claim 1 , wherein the transistor is a Si metal oxide semiconductor field effect transistor (MOSFET).
7 . The medical sensing system of claim 1 , wherein the transistor is a GaAs MESFET, an InP FET, a heterojunction bipolar transistor, a SiCMOS transistor, a SiGe FET, a biCMOS transistor or an III-V semiconductor based high electron mobility transistor (HEMT).
8 . The medical sensing system of claim 7 , wherein the III-V semiconductor based HEMT is a GaAs, InAlAs or InGaAs based HEMT.
9 . The medical sensing system of claim 1 , wherein the functionalized sensing area is disposed between the first and second electrodes and comprises at least one end of the first electrode and at least one end of the second electrode.
10 . The medical sensing system of claim 9 , wherein the functionalized sensing area is disposed between the first and second electrodes and comprises one end of the first electrode and one end of the second electrode.
11 . The medical sensing system of claim 1 , wherein the first and second electrodes are Ni/Au based metal electrodes disposed on the substrate.
12 . The medical sensing system of claim 1 , wherein the substrate comprises a ceramic strip, a paper strip or a plastic strip.
13 . The medical sensing system of claim 12 , wherein the plastic strip is a polyethylene terephthalate (PET) strip.
14 . The medical sensing system of claim 1 , wherein the disposable sensing unit comprises microfluid channels extending between a sample deposit opening and the functionalized sensing area.
15 . The medical sensing system of claim 14 , wherein disposable sensing unit comprises a plurality of functionalized sensing areas.