US4825851A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for comminuting kidney stones
Assignee: Duke University
•
Filing: 1987-12-14
•
Granted: 1989-05-02
•
Expires: 2007-12-14
Abstract
Abstract A method for comminuting kidney stones including treating a stone to be comminuted with a surface energy-lowering solution and applying acoustic impulses to the stone so as to pulverize the stone into fragments small enough to be passed through the ureter and urethra.
Inventors
- 👤 Franklin H. Cocks
- 👤 Scott R. Akers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 07:01
CPC Classifications
A; A61; A61B; A61B17/00; A61B17/22; A61B17/225; A61B17/22004; A61K; A61K31/00; A61K31/185; A61K31/19; A61B2017/22082; A61B2017/22084
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
85 words
A lithotripter method for comminuting kidney stones comprising: introducing a surface energy-lowering solution other than urine into a kidney through a catheter such that a stone within the kidney is exposed to said solution for at least 5 minutes; and applying at least 200 focused intense acoustic impulses to the stone after introduction of said solution; whereby the stone is comminuted into fragments small enough to be passed through the ureter and urethra with minimized risk of damage to the kidney from said acoustic impulses.
Claim 2
Dependent Claim
85 words
A lithotripter method for comminuting kidney stones comprising: introducing a surface energy-lowering solution other than urine into a kidney through a catheter such that a stone within the kidney is exposed to said solution for at least 5 minutes; and applying at least 200 focused intense acoustic impulses to the stone after introduction of said solution; whereby the stone is comminuted into fragments small enough to be passed through the ureter and urethra with minimized risk of damage to the kidney from said acoustic impulses.
Claim 3
Dependent Claim
16 words
A method according to claim 1 wherein the surface energy-lowering solution is a citric acid solution.
Claim 4
Dependent Claim
16 words
A method according to claim 2 wherein the stone to be communicated is a phosphate stone.
Claim 5
Dependent Claim
76 words
A lithotripter method for comminuting phosphate kidney stones comprising: introducing a citric acid surface energy lowering solution into a kidney through a catheter such that a stone within the kidney is exposed to said citric acid solution; and applying at least 200 focused intense acoustic impulses which produce pressure waves greater than 1 kbar in amplitude to the stone; whereby the stone is comminuted into fragments small enough to be passed through the ureter and urethra.
Claim 6
Dependent Claim
76 words
A lithotripter method for comminuting phosphate kidney stones comprising: introducing a citric acid surface energy lowering solution into a kidney through a catheter such that a stone within the kidney is exposed to said citric acid solution; and applying at least 200 focused intense acoustic impulses which produce pressure waves greater than 1 kbar in amplitude to the stone; whereby the stone is comminuted into fragments small enough to be passed through the ureter and urethra.
Claim 7
Dependent Claim
55 words
A method according to claim 4 wherein the citric acid solution comprises from about 20 to about 40 grams of citric acid, from about 2 to about 6 grams of anhydrous magnesium oxide, from about 3 to about 7 grams of anhydrous sodium carbonate and from about 800 to about 1200 cc of distilled water.
Claim 8
Dependent Claim
27 words
A method according to claim 4 wherein the stone is exposed to the citric acid solution for at least 5 minutes before the acoustic impulses are applied.
References Cited (Backward Citations)
JPS577416A
Cited
JPH0219154A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-05-01 | 1992-10-31 | 1993-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-01 | 1996-10-31 | 1997-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-01 | 2000-10-31 | 2001-05-02 | $7700.00 | Window Closed / Lapsed |