GB2308652A - Temperature-sensitive catheter - Google Patents
Temperature-sensitive catheter Download PDFInfo
- Publication number
- GB2308652A GB2308652A GB9526587A GB9526587A GB2308652A GB 2308652 A GB2308652 A GB 2308652A GB 9526587 A GB9526587 A GB 9526587A GB 9526587 A GB9526587 A GB 9526587A GB 2308652 A GB2308652 A GB 2308652A
- Authority
- GB
- United Kingdom
- Prior art keywords
- temperature
- catheter
- sensitive
- optic cable
- fibre optic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000000835 fiber Substances 0.000 claims description 25
- 239000000463 material Substances 0.000 claims description 3
- 230000003287 optical effect Effects 0.000 claims description 3
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims description 2
- 229910052721 tungsten Inorganic materials 0.000 claims description 2
- 239000010937 tungsten Substances 0.000 claims description 2
- 239000003814 drug Substances 0.000 description 5
- 229940079593 drug Drugs 0.000 description 5
- 238000003780 insertion Methods 0.000 description 5
- 230000037431 insertion Effects 0.000 description 5
- 208000015181 infectious disease Diseases 0.000 description 4
- 238000005259 measurement Methods 0.000 description 3
- 229920000915 polyvinyl chloride Polymers 0.000 description 3
- 239000004800 polyvinyl chloride Substances 0.000 description 3
- 239000008280 blood Substances 0.000 description 2
- 210000004369 blood Anatomy 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 230000017531 blood circulation Effects 0.000 description 1
- 210000004204 blood vessel Anatomy 0.000 description 1
- 238000009529 body temperature measurement Methods 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000012377 drug delivery Methods 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 229920001296 polysiloxane Polymers 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 239000004814 polyurethane Substances 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 230000002277 temperature effect Effects 0.000 description 1
- 230000002123 temporal effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K11/00—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
- G01K11/32—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in transmittance, scattering or luminescence in optical fibres
- G01K11/3206—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in transmittance, scattering or luminescence in optical fibres at discrete locations in the fibre, e.g. using Bragg scattering
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M25/00—Catheters; Hollow probes
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M25/00—Catheters; Hollow probes
- A61M25/0017—Catheters; Hollow probes specially adapted for long-term hygiene care, e.g. urethral or indwelling catheters to prevent infections
Landscapes
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Biomedical Technology (AREA)
- Heart & Thoracic Surgery (AREA)
- Biophysics (AREA)
- Pulmonology (AREA)
- Engineering & Computer Science (AREA)
- Anesthesiology (AREA)
- Veterinary Medicine (AREA)
- Public Health (AREA)
- Hematology (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Urology & Nephrology (AREA)
- Epidemiology (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)
Description
A TEMPERATURE-SENSITIVE CATHETER
This invention relates to improvements in catheters.
Catheters can be inserted into a human or animal body intravascularly in order to infuse drugs or fluids or to measure some property of the body at a particular site, e.g.
blood flow rate.
There is a finite possibility of infection due to the catheter insertion, mainly at two sites:- at the tip of the catheter, and at the insertion site. Detection of infection is normally difficult in the early stages. The first indication is a temperature rise at the site of the infection. The invention can be used to measure the temperature at the tip of the catheter, at the insertion site and at several points in between, thereby giving an early indication of the onset of any infection.
According to the invention, a temperature-sensitive catheter comprises an elongate catheter body and a fibre optic cable affixed thereto wherein the fibre optic cable incorporates at least one optical grating.
The temperature measurement technique depends on the variability of the Bragg wavelength of an induced grating within a fibre optic cable. The grating can be formed by a variation in the refractive index of the fibre core written when the fibre is drawn. The Bragg wavelength of reflected light from the grating is a function of temperature and strain of the fibre at the site of the grating. In this application temperature effects will dominate and strain will be regarded as constant.
By writing several gratings into the fibre distributed along its length, the temperature can be measured at several sites. This requires discrimination between the various sites. Because the length of fibre required is relatively short, temporal discrimination is impractical and in the preferred embodiment wavelength discrimination is used. In this case the gratings are written with different frequencies so that there is a significant change in Bragg wavelength between gratings.
Advantageously, the invention measures temperature optically, requiring no introduction of electrical conductors or electrical potentials or currents into a patient's body, thereby being electrically safe and avoiding electrical interference from external sources.
The invention covers the measurement of temperature for both short term (e.g. during clinical procedures) and long term monitoring.
The fibre optic cable may be located by means of embedding the fibre into the core of the catheter body. The catheter body could in this case typically consist of many lumens or cavities into one of which the fibre would be fed.
Alternatively the fibre may be secured at the insertion site using a stud or button which would fasten to the outside of the catheter body once it was in position intravascularly.
The latter arrangement offers the advantage of lower risk to the patient should the fibre fracture or break within the catheter.
The catheter body can be made from a wide range of materials which are polymeric in origin, although any requirement to exhibit enhanced blood compatibility will limit the number of polymers that can be used. Examples with good blood compatibility include polyurethane, polyvinyl chloride and silicone.
Further advantages of the invention are; the possibility of computer interfacing for data logging, a sensitivity of 0.001k, operation which is independent of drug dose rate, minimal interference with drug delivery systems and the capability of use with small blood vessels.
An embodiment of the invention will now be described, by way of example only, with reference to the drawings of which:
Figure 1 is a sectional side view of a catheter in accordance with the invention, and
Figure 2 is a cross-sectional view along a line Il-Il' of
Figure 1.
Referring to Figure 1, a catheter comprises an elongate catheter body 1 which incorporates a central channel 2 for the injection of fluid (drugs eg) into a patient's body. The catheter body 1 includes a further channel 3 into which is inserted a fibre optic cable 4.
The fibre optic cable 4 is connected at one of its ends to a laser diode light source 5 and measurement system 6.
Gratings 7 are written into the fibre optic cable 4 at several locations along its length.
Referring now to Figure 2, the catheter body 1 is drawn from PVC and (optionally) incorporates a thermally-conducting segment 8, which runs the length of the catheter body 1 and is located adjacent to the fibre optic cable 4 so that good thermal conductivity between the fibre 4 and the outside of the catheter but not the inside of the catheter exists.
Good conductivity between the fibre 4 and the inner walls of the catheter body would result in the temperature sensed being contaminated by the temperature of the drugs being introduced into the patient's body. This is undesirable, therefore the thermally-conducting segment 8 is confined to the peripheral region of the catheter body 1.
As a further option the segment 8 can also be made to be radio-opaque thereby permitting X-ray tracking of the catheter within the patient's body. A suitable material for the segment 8 in this example is tungsten-loaded PVC.
In use, the catheter is inserted into a patient's body as appropriate, the drug dose is administered as appropriate and the light source 5 is activated.
By monitoring the frequencies of light reflected from the individual gratings 7, the measurement system 6 is able to monitor the temperature of the surrounding patient's tissue at the insertion site and catheter tip and various points in between.
Claims (10)
1. A temperature-sensitive catheter comprising an elongate
catheter body and a fibre optic cable affixed thereto
wherein the fibre optic cable incorporates at least one
optical grating.
2. A temperature-sensitive catheter according to claim 1 in
which said optical grating is formed by a variation in
refractive index of the core of said fibre optic cable.
3. A temperature-sensitive catheter according to claim 1 or
claim 2 and incorporating a plurality of gratings, each
of said gratings having a different Bragg wavelength.
4. A temperature sensitive-catheter according to any
preceding claim in which the catheter body includes a
channel running along its length, in which is located
said fibre optic cable.
5. A temperature-sensitive catheter according to any of
claims 1 to 3 in which the catheter body includes
securing means for fastening said fibre optic cable to
the outer surface of the catheter body.
6. A temperature-sensitive catheter according to claim 4 in
which the catheter body incorporates a thermally
conducting segment located adjacent to said fibre optic
cable and running the length of the catheter body.
7. A temperature-sensitive catheter according to claim 6 in
which said thermally-conducting segment is opaque to
X-rays.
8. A temperature-sensitive catheter according to claim 7 in
which said thermally-conducting segment is composed of
tungsten-loaded PVC.
9. A temperature-sensitive catheter according to any
preceding claim in which the catheter body is drawn from
a polymeric material.
10. A temperature-sensitive catheter substantially as
hereinbefore described with reference to the drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9526587A GB2308652B (en) | 1995-12-28 | 1995-12-28 | A temperature-sensitive catheter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9526587A GB2308652B (en) | 1995-12-28 | 1995-12-28 | A temperature-sensitive catheter |
Publications (4)
| Publication Number | Publication Date |
|---|---|
| GB9526587D0 GB9526587D0 (en) | 1996-02-28 |
| GB2308652A true GB2308652A (en) | 1997-07-02 |
| GB2308652A8 GB2308652A8 (en) | 1999-03-25 |
| GB2308652B GB2308652B (en) | 2000-07-19 |
Family
ID=10786118
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9526587A Expired - Fee Related GB2308652B (en) | 1995-12-28 | 1995-12-28 | A temperature-sensitive catheter |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2308652B (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2346965A (en) * | 1999-02-18 | 2000-08-23 | Oxford Fiber Optic Tools Ltd | Fibre optic grating sensor |
| WO2003051449A1 (en) * | 2001-12-14 | 2003-06-26 | Scimed Life Systems, Inc. | Dilation catheter assembly and related methods |
| CN100490737C (en) * | 2007-07-20 | 2009-05-27 | 华中科技大学 | Device and method for detecting depth of anesthesia |
| EP2713861A1 (en) * | 2011-06-01 | 2014-04-09 | Koninklijke Philips N.V. | System for distributed blood flow measurement |
| EP2403402A4 (en) * | 2009-03-04 | 2016-04-06 | Imricor Medical Systems Inc | Mri compatible medical device temperature monitoring system and method |
| EP3831284A1 (en) | 2019-12-05 | 2021-06-09 | Elmedix NV | Invasive temperature sensor system |
| US12551110B2 (en) | 2019-12-05 | 2026-02-17 | Elmedix Nv | Invasive temperature sensor system |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0259973A2 (en) * | 1986-09-10 | 1988-03-16 | John E. Shulze | Fluorometric sensor system using heterodyne technique |
| US4806012A (en) * | 1984-08-13 | 1989-02-21 | United Technologies Corporation | Distributed, spatially resolving optical fiber strain gauge |
| US4868381A (en) * | 1986-10-03 | 1989-09-19 | Optical Technologies, Inc. | Fiber optic interferometric thermometer |
| WO1989011311A1 (en) * | 1988-05-18 | 1989-11-30 | Kasevich Associates, Inc. | Microwave balloon angioplasty |
| US4996419A (en) * | 1989-12-26 | 1991-02-26 | United Technologies Corporation | Distributed multiplexed optical fiber Bragg grating sensor arrangeement |
| GB2268581A (en) * | 1992-07-03 | 1994-01-12 | Marconi Gec Ltd | Optical fibre diffraction grating sensor |
| WO1994017366A1 (en) * | 1993-01-29 | 1994-08-04 | United Technologies Corporation | Active multipoint fiber laser sensor |
-
1995
- 1995-12-28 GB GB9526587A patent/GB2308652B/en not_active Expired - Fee Related
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4806012A (en) * | 1984-08-13 | 1989-02-21 | United Technologies Corporation | Distributed, spatially resolving optical fiber strain gauge |
| EP0259973A2 (en) * | 1986-09-10 | 1988-03-16 | John E. Shulze | Fluorometric sensor system using heterodyne technique |
| US4868381A (en) * | 1986-10-03 | 1989-09-19 | Optical Technologies, Inc. | Fiber optic interferometric thermometer |
| WO1989011311A1 (en) * | 1988-05-18 | 1989-11-30 | Kasevich Associates, Inc. | Microwave balloon angioplasty |
| US4996419A (en) * | 1989-12-26 | 1991-02-26 | United Technologies Corporation | Distributed multiplexed optical fiber Bragg grating sensor arrangeement |
| GB2268581A (en) * | 1992-07-03 | 1994-01-12 | Marconi Gec Ltd | Optical fibre diffraction grating sensor |
| WO1994017366A1 (en) * | 1993-01-29 | 1994-08-04 | United Technologies Corporation | Active multipoint fiber laser sensor |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2346965A (en) * | 1999-02-18 | 2000-08-23 | Oxford Fiber Optic Tools Ltd | Fibre optic grating sensor |
| GB2346965B (en) * | 1999-02-18 | 2002-01-16 | Oxford Fiber Optic Tools Ltd | Fibre optic grating sensor |
| WO2003051449A1 (en) * | 2001-12-14 | 2003-06-26 | Scimed Life Systems, Inc. | Dilation catheter assembly and related methods |
| US7029450B2 (en) | 2001-12-14 | 2006-04-18 | Boston Scientific Scimed, Inc. | Dilation catheter assembly and related methods |
| CN100490737C (en) * | 2007-07-20 | 2009-05-27 | 华中科技大学 | Device and method for detecting depth of anesthesia |
| EP2403402A4 (en) * | 2009-03-04 | 2016-04-06 | Imricor Medical Systems Inc | Mri compatible medical device temperature monitoring system and method |
| EP2713861A1 (en) * | 2011-06-01 | 2014-04-09 | Koninklijke Philips N.V. | System for distributed blood flow measurement |
| US11553852B2 (en) | 2011-06-01 | 2023-01-17 | Koninklijke Philips N.V. | System for distributed blood flow measurement |
| EP3831284A1 (en) | 2019-12-05 | 2021-06-09 | Elmedix NV | Invasive temperature sensor system |
| WO2021111014A1 (en) | 2019-12-05 | 2021-06-10 | Elmedix Nv | Invasive temperature sensor system |
| US12551110B2 (en) | 2019-12-05 | 2026-02-17 | Elmedix Nv | Invasive temperature sensor system |
Also Published As
| Publication number | Publication date |
|---|---|
| GB9526587D0 (en) | 1996-02-28 |
| GB2308652A8 (en) | 1999-03-25 |
| GB2308652B (en) | 2000-07-19 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20051228 |